Sample records for jnk-specific inhibitor sp600125

  1. Effect of JNK inhibitor SP600125 on hair cell regeneration in zebrafish (Danio rerio) larvae

    PubMed Central

    Sun, Shaoyang; Wang, Xu; Li, Wenyan; Li, Huawei

    2016-01-01

    The c-Jun amino-terminal kinase (JNK) proteins are a subgroup of the mitogen-activated protein kinase family. They play a complex role in cell proliferation, survival, and apoptosis. Here, we report a novel role of JNK signalling in hair cell regeneration. We eliminated hair cells of 5-day post-fertilization zebrafish larvae using neomycin followed by JNK inhibition with SP600125. JNK inhibition strongly decreased the number of regenerated hair cells in response to neomycin damage. These changes were associated with reduced proliferation. JNK inhibition also increased cleaved caspase-3 activity and induced apoptosis in regenerating neuromasts. Finally, JNK inhibition with SP600125 decreased the expression of genes related to Wnt. Over-activation of the Wnt signalling pathway partly rescued the hair cell regeneration defects induced by JNK inhibition. Together, our findings provide novel insights into the function of JNK and show that JNK inhibition blocks hair cell regeneration by controlling the Wnt signalling pathway. PMID:27438150

  2. Inhibition of adrenergic human prostate smooth muscle contraction by the inhibitors of c-Jun N-terminal kinase, SP600125 and BI-78D3.

    PubMed

    Strittmatter, F; Walther, S; Gratzke, C; Göttinger, J; Beckmann, C; Roosen, A; Schlenker, B; Hedlund, P; Andersson, K E; Stief, C G; Hennenberg, M

    2012-07-01

    BACKGROUND AND PURPOSE α(1) -Adrenoceptor-induced contraction of prostate smooth muscle is mediated by calcium- and Rho kinase-dependent mechanisms. In addition, other mechanisms, such as activation of c-jun N-terminal kinase (JNK) may be involved. Here, we investigated whether JNK participates in α(1)-adrenoceptor-induced contraction of human prostate smooth muscle. EXPERIMENTAL APPROACH Prostate tissue was obtained from patients undergoing radical prostatectomy. Effects of the JNK inhibitors SP600125 (50 µM) and BI-78D3 (30 µM) on contractions induced by phenylephrine, noradrenaline and electric field stimulation (EFS) were studied in myographic measurements. JNK activation by noradrenaline (30 µM) and phenylephrine (10 µM), and the effects of JNK inhibitors of c-Jun phosphorylation were assessed by Western blot analyses with phospho-specific antibodies. Expression of JNK was studied by immunohistochemistry and fluorescence double staining. KEY RESULTS The JNK inhibitors SP600125 and BI-78D3 reduced phenylephrine- and noradrenaline-induced contractions of human prostate strips. In addition, SP600125 reduced EFS-induced contraction of prostate strips. Stimulation of prostate tissue with noradrenaline or phenylephrine in vitro resulted in activation of JNK. Incubation of prostate tissue with SP600125 or BI-78D3 reduced the phosphorylation state of c-Jun. Immunohistochemical staining demonstrated the expression of JNK in smooth muscle cells of human prostate tissue. Fluorescence staining showed that α(1A)-adrenoceptors and JNK are expressed in the same cells. CONCLUSIONS AND IMPLICATIONS Activation of JNK is involved in α(1)-adrenoceptor-induced prostate smooth muscle contraction. Models of α(1)-adrenoceptor-mediated prostate smooth muscle contraction should include this JNK-dependent mechanism. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

  3. SP600125 promotes resolution of allergic airway inflammation via TLR9 in an OVA-induced murine acute asthma model.

    PubMed

    Wu, Hui-Mei; Fang, Lei; Shen, Qi-Ying; Liu, Rong-Yu

    2015-10-01

    c-Jun N-terminal kinase (JNK) relays extracellular stimuli through phosphorylation cascades that lead to various cell responses. In the present study, we aimed to investigate the effect of the JNK inhibitor SP600125 on the resolution of airway inflammation, and the underlying mechanism using a murine acute asthma model. Female C57BL/6 mice were sensitized with saline or ovalbumin (OVA) on day 0, and challenged with OVA on day 14-20. Meanwhile, some of the mice were treated with SP600125 (30 mg/kg) intraperitoneally 2 h before each challenge. The airway inflammation was evaluated by counting the numbers of various types of inflammatory cells in bronchoalveolar lavage fluid (BALF), histopathology, cytokines production and mucus secretion in individual mouse. In addition, we analyzed the protein levels of phosphorylated JNK and TLR9 in the lung tissues. SP600125 markedly reduced the invasion of inflammatory cells into the peribronchial regions, and decreased the numbers of eosinophils, monocytes, neutrophils and lymphocytes in BALF. SP600125 also reduced the level of plasma OVA-specific IgE, lowered the production of pro-inflammatory cytokines in BALF and alleviated mucus secretion. Meanwhile, SP600125 inhibited OVA-induced, increased expression of p-JNK and TLR9 in the lung tissues. Collectively, our data demonstrated that SP600125 promoted resolution of allergic airway inflammation via TLR9 in an OVA-induced murine acute asthma model. The JNK-TLR9 pathway may be a new therapeutic target in the treatment for the allergic asthma. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Autotetraploid cell Line induced by SP600125 from crucian carp and its developmental potentiality

    PubMed Central

    Zhou, Yonghua; Wang, Mei; Jiang, Minggui; Peng, Liangyue; Wan, Cong; Liu, Jinhui; Liu, Wenbin; Zhao, Rurong; Zhao, Xiaoyang; Hu, Wei; Liu, Shaojun; Xiao, Yamei

    2016-01-01

    Polyploidy has many advantages over diploidy, such as rapid growth, sterility, and disease resistance, and has been extensively applied in agriculture and aquaculture. Though generation of new polyploids via polyploidization has been achieved in plants by different ways, it is comparatively rare in animals. In this article, by a chemical compound, SP600125, polyploidization is induced in fish cells in vitro, and a stable autotetraploid cell line has been generated from diploid fibroblast cells of crucian carp. As a c-Jun N-terminal kinase (Jnk) inhibitor, SP600125 does not function during the induction process of polyploidization. Instead, the p53 signal pathway might be involved. Using the SP600125-induced tetraploid cells and eggs of crucian carp as the donors and recipients, respectively, nuclear transplantation was conducted such that tetraploid embryos were obtained. It suggests that combining polyploidization and the somatic cell nuclear transfer technique (SCNT) is an efficient way to generate polyploidy, and the presented method in this research for generating the tetraploid fish from diploid fish can provide a useful platform for polyploid breeding. PMID:26898354

  5. [Protein kinase A inhibitor H-89 blocks polyploidization of SP600125-induced CMK cells by regulating phosphorylation of ribosomal protein S6 kinase 1].

    PubMed

    Zhao, Song; Yang, Jingang; Li, Changling; Xing, Sining; Yu, Ying; Liu, Shuo; Pu, Feifei; Ma, Dongchu

    2016-10-01

    Objective To investigate the regulatory effect of post-translation modification of ribosomal protein S6 kinase 1 (S6K1) on the polyploidization of megakaryocytes. Methods SP600125, a c-Jun N-terminal kinase (JNK) inhibitor, and H-89, a cAMP-dependent protein kinase (PKA) inhibitor, were used to treat CMK cells separately or in combination. With propidium iodide (PI) to dye DNA in the treated cells, the relative DNA content was detected by flow cytometry, and then the DNA polyploidy was analyzed. The change of expression and phosphorylation of ribosomal protein S6 kinase 1 (S6K1), an important mammalian target of rapamycin (mTOR) downstream target molecule, was analyzed by Western blotting. Molecular docking study and kinase activity assay were performed to analyze the combination of H-89 with S6K1 and the effect of H-89 on the activity of S6K1 kinase. Results SP600125 induced CMK cell polyploidization in a time-dependent and dose-dependent manner. At the same time, it increased the phosphorylation of S6K1 at Thr421/Ser424 and decreased the phosphorylation of S6K1 at Thr389. H-89 not only blocked polyploidization, but also decreased the phosphorylation of S6K1 at Thr421/Ser424 and increased the phosphorylation of S6K1 at Thr389. Molecular docking and kinase activity assay showed that H-89 occupied the ATP binding sites of S6K1 and inhibited its activity. Noticeably, both H-89 and SP600125 inhibited the activity of PKA. Moreover, the two drugs further inhibited the activity of PKA when used together. Therefore, these data indicated that H-89 blocked the SP600125-induced polyploidization of CMK cells mainly by changing S6K1 phosphorylation state, rather than its inhibitory effect on PKA. Conclusion H-89 can block the polyploidization of SP600125-induced CMK cells by regulating S6K1 phosphorylation state.

  6. Indazole-based potent and cell-active Mps1 kinase inhibitors: rational design from pan-kinase inhibitor anthrapyrazolone (SP600125).

    PubMed

    Kusakabe, Ken-ichi; Ide, Nobuyuki; Daigo, Yataro; Tachibana, Yuki; Itoh, Takeshi; Yamamoto, Takahiko; Hashizume, Hiroshi; Hato, Yoshio; Higashino, Kenichi; Okano, Yousuke; Sato, Yuji; Inoue, Makiko; Iguchi, Motofumi; Kanazawa, Takayuki; Ishioka, Yukichi; Dohi, Keiji; Kido, Yasuto; Sakamoto, Shingo; Yasuo, Kazuya; Maeda, Masahiro; Higaki, Masayo; Ueda, Kazuo; Yoshizawa, Hidenori; Baba, Yoshiyasu; Shiota, Takeshi; Murai, Hitoshi; Nakamura, Yusuke

    2013-06-13

    Monopolar spindle 1 (Mps1) is essential for centrosome duplication, the spindle assembly check point, and the maintenance of chromosomal instability. Mps1 is highly expressed in cancer cells, and its expression levels correlate with the histological grades of cancers. Thus, selective Mps1 inhibitors offer an attractive opportunity for the development of novel cancer therapies. To design novel Mps1 inhibitors, we utilized the pan-kinase inhibitor anthrapyrazolone (4, SP600125) and its crystal structure bound to JNK1. Our design efforts led to the identification of indazole-based lead 6 with an Mps1 IC50 value of 498 nM. Optimization of the 3- and 6-positions on the indazole core of 6 resulted in 23c with improved Mps1 activity (IC50 = 3.06 nM). Finally, application of structure-based design using the X-ray structure of 23d bound to Mps1 culminated in the discovery of 32a and 32b with improved potency for cellular Mps1 and A549 lung cancer cells. Moreover, 32a and 32b exhibited reasonable selectivities over 120 and 166 kinases, respectively.

  7. [SP600125-induced polyploidization of megakaryocytic leukemia cell lines by ribosomal protein S6 kinase 1 depends on the degree of cell differentiation].

    PubMed

    Wang, Lili; Yang, Jingang; Li, Changling; Xing, Sining; Yu, Ying; Liu, Shuo; Zhao, Song; Ma, Dongchu

    2016-10-01

    Objective To investigate regulatory role of ribosomal protein S6 kinase 1 (S6K1) in the polyploidization of different megakaryocytic leukemia cell lines at the different differentiation stages. Methods Megakaryocytic leukemia cell lines (Dami, Meg-01 and HEL cells) were induced towards polyploidization by SP600125, a c-Jun N-terminal kinase (JNK) inhibitor. The SP600125-inducing process was blocked by H-89, a cAMP-dependent protein kinase (PKA) inhibitor. The phenotype (CD41a, CD42a and CD42b) and DNA ploidy were detected by flow cytometry. The expression and phosphorylation of S6K1 and related proteins were detected by Western blotting. Results SP600125 induced polyploidization and increased the phosphorylation of eukaryotic initiation factor 4E binding protein 1 (4E-BP1) in Dami, Meg-01 and HEL cells. However, the effect of SP600125 on polyploidization of the three cell lines was different, with the strongest effect on Dami cells and the weakest on Meg-01 cells. Moreover, SP600125 increased the phosphorylation of S6K1 Thr421/Ser424 and decreased the phosphorylation of Thr389 in Dami cells. However, it only increased the phosphorylation of Thr389 in HEL cells and had no effect on the phosphorylation of S6K1 in Meg-01 cells. Interestingly, H-89 only partially blocked the polyploidization of Dami cells, although it decreased the phosphorylation of 4E-BP1 in all SP600125-induced three cell lines. Noticeably, H-89 decreased the phosphorylation of S6K1 Thr421/Ser424 and increased the phosphorylation of Thr389 in Dami cells. However, H-89 had no effect on the phosphorylation of Thr421/Ser424, although it increased the phosphorylation of Thr389 in Meg-01 and HEL cells. Phenotypic analysis showed that the three cell lines were at different levels of differentiation in megakaryocytic lineage, with the highest differentiation in Dami and the lowest in Meg-01 cells. Conclusion SP600125-induced polyploidization of megakaryocytic leukemia cell lines is dependent on the effect

  8. Dexmedetomidine-induced Contraction Involves Phosphorylation of Caldesmon by JNK in Endothelium-denuded Rat Aortas

    PubMed Central

    Baik, Jiseok; Ok, Seong-Ho; Cho, Hyunhoo; Yu, Jongsun; Kim, Woochan; Nam, In-Koo; Choi, Mun-Jeoung; Lee, Heon-Keun; Sohn, Ju-Tae

    2014-01-01

    Caldesmon, an inhibitory actin binding protein, binds to actin and inhibits actin-myosin interactions, whereas caldesmon phosphorylation reverses the inhibitory effect of caldesmon on actin-myosin interactions, potentially leading to enhanced contraction. The goal of this study was to investigate the cellular signaling pathway responsible for caldesmon phosphorylation, which is involved in the regulation of the contraction induced by dexmedetomidine (DMT), an alpha-2 adrenoceptor agonist, in endothelium-denuded rat aortas. SP600125 (a c-Jun NH2-terminal kinase [JNK] inhibitor) dose-response curves were generated in aortas that were pre-contracted with DMT or phorbol 12,13-dibutyrate (PDBu), a protein kinase C (PKC) activator. Dose-response curves to the PKC inhibitor chelerythrine were generated in rat aortas pre-contracted with DMT. The effects of SP600125 and rauwolscine (an alpha-2 adrenoceptor inhibitor) on DMT-induced caldesmon phosphorylation in rat aortic vascular smooth muscle cells (VSMCs) were investigated by western blot analysis. PDBu-induced caldesmon and DMT-induced PKC phosphorylation in rat aortic VSMCs was investigated by western blot analysis. The effects of GF109203X (a PKC inhibitor) on DMT- or PDBu-induced JNK phosphorylation in VSMCs were assessed. SP600125 resulted in the relaxation of aortas that were pre-contracted with DMT or PDBu, whereas rauwolscine attenuated DMT-induced contraction. Chelerythrine resulted in the vasodilation of aortas pre-contracted with DMT. SP600125 and rauwolscine inhibited DMT-induced caldesmon phosphorylation. Additionally, PDBu induced caldesmon phosphorylation, and GF109203X attenuated the JNK phosphorylation induced by DMT or PDBu. DMT induced PKC phosphorylation in rat aortic VSMCs. These results suggest that alpha-2 adrenoceptor-mediated, DMT-induced contraction involves caldesmon phosphorylation that is mediated by JNK phosphorylation by PKC. PMID:25332685

  9. Involvement of the Tyr kinase/JNK pathway in carbachol-induced bronchial smooth muscle contraction in the rat.

    PubMed

    Sakai, Hiroyasu; Watanabe, Yu; Honda, Mai; Tsuiki, Rika; Ueda, Yusuke; Nagai, Yuki; Narita, Minoru; Misawa, Miwa; Chiba, Yoshihiko

    2013-05-01

    Tyrosine (Tyr) kinases and mitogen-activated protein kinases have been thought to participate in the contractile response in various smooth muscles. The aim of the current study was to investigate the involvement of the Tyr kinase pathway in the contraction of bronchial smooth muscle. Ring preparations of bronchi isolated from rats were suspended in an organ bath. Isometric contraction of circular smooth muscle was measured. Immunoblotting was used to examine the phosphorylation of c-Jun N-terminal kinasess (JNKs) in bronchial smooth muscle. To examine the role of mitogen-activated protein kinase(s) in bronchial smooth muscle contraction, the effects of MPAK inhibitors were investigated in this study. The contraction induced by carbachol (CCh) was significantly inhibited by pretreatment with selective Tyr kinase inhibitors (genistein and ST638, n = 6, respectively), and a JNK inhibitor (SP600125, n = 6). The contractions induced by high K depolarization (n = 4), orthovanadate (a potent Tyr phosphatase inhibitor) and sodium fluoride (a G protein activator; NaF) were also significantly inhibited by selective Tyr kinase inhibitors and a JNK inhibitor (n = 4, respectively). However, the contraction induced by calyculin-A was not affected by SP600125. On the other hand, JNKs were phosphorylated by CCh (2.2 ± 0,4 [mean±SEM] fold increase). The JNK phosphorylation induced by CCh was significantly inhibited by SP600125 (n = 4). These findings suggest that the Tyr kinase/JNK pathway may play a role in bronchial smooth muscle contraction. Strategies to inhibit JNK activation may represent a novel therapeutic approach for diseases involving airway obstruction, such as asthma and chronic obstructive pulmonary disease.

  10. Inhibitor of Nicotinamide Phosphoribosyltransferase Sensitizes Glioblastoma Cells to Temozolomide via Activating ROS/JNK Signaling Pathway.

    PubMed

    Feng, Jun; Yan, Peng-Fei; Zhao, Hong-Yang; Zhang, Fang-Cheng; Zhao, Wo-Hua; Feng, Min

    2016-01-01

    Overcoming temozolomide (TMZ) resistance is a great challenge in glioblastoma (GBM) treatment. Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme in the biosynthesis of nicotinamide adenine dinucleotide and has a crucial role in cancer cell metabolism. In this study, we investigated whether FK866 and CHS828, two specific NAMPT inhibitors, could sensitize GBM cells to TMZ. Low doses of FK866 and CHS828 (5 nM and 10 nM, resp.) alone did not significantly decrease cell viability in U251-MG and T98 GBM cells. However, they significantly increased the antitumor action of TMZ in these cells. In U251-MG cells, administration of NAMPT inhibitors increased the TMZ (100  μ M)-induced apoptosis and LDH release from GBM cells. NAMPT inhibitors remarkably enhanced the activities of caspase-1, caspase-3, and caspase-9. Moreover, NAMPT inhibitors increased reactive oxygen species (ROS) production and superoxide anion level but reduced the SOD activity and total antioxidative capacity in GBM cells. Treatment of NAMPT inhibitors increased phosphorylation of c-Jun and JNK. Administration of JNK inhibitor SP600125 or ROS scavenger tocopherol with TMZ and NAMPT inhibitors substantially attenuated the sensitization of NAMPT inhibitor on TMZ antitumor action. Our data indicate a potential value of NAMPT inhibitors in combined use with TMZ for GBM treatment.

  11. JNK1 regulates histone acetylation in trigeminal neurons following chemical stimulation

    PubMed Central

    Wu, Jing; Zhang, Xuan; Nauta, Haring J; Lin, Qing; Li, Junfa; Fang, Li

    2008-01-01

    Trigeminal nerve fibers in nasal and oral cavities are sensitive to various environmental hazardous stimuli, which trigger many neurotoxic problems such as chronic migraine headache and trigeminal irritated disorders. However, the role of JNK kinase cascade and its epigenetic modulation of histone remodeling in trigeminal ganglion (TG) neurons activated by environmental neurotoxins remains unknown. Here we investigated the role of JNK/c-Jun cascade in the regulation of acetylation of H3 histone in TG neurons following in vitro stimulation by a neuro-inflammatory agent, mustard oil (MO). We found that MO stimulation elicited JNK/c-Jun pathway significantly by enhancing phospho-JNK1, phospho-c-Jun expression, and c-Jun activity, which were correlated with an elevated acetylated H3 histone in TG neurons. However, increases in phospho-c-Jun and c-Jun activity were significantly blocked by a JNK inhibitor, SP600125. We also found that altered H3 histone remodeling, assessed by H3 acetylation in triggered TG neurons, was reduced by SP600125. The study suggests that the activated JNK signaling in regulation of histone remodeling may contribute to neuro-epigentic changes in peripheral sensory neurons following environmental neurotoxic exposure. PMID:18822271

  12. Tumor necrosis factor-{alpha} induces MMP-9 expression via p42/p44 MAPK, JNK, and nuclear factor-{kappa}B in A549 cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lin, C.-C.; Tseng, Hsiao-Wei; Hsieh, Hsi-Lung

    2008-06-15

    Matrix metalloproteinases (MMPs), in particular MMP-9, have been shown to be induced by cytokines including tumor necrosis factor-{alpha} (TNF-{alpha}) and contributes to airway inflammation. However, the mechanisms underlying MMP-9 expression induced by TNF-{alpha} in human A549 cells remain unclear. Here, we showed that TNF-{alpha} induced production of MMP-9 protein and mRNA is determined by zymographic, Western blotting, RT-PCR and ELISA assay, which were attenuated by inhibitors of MEK1/2 (U0126), JNK (SP600125), and NF-{kappa}B (helenalin), and transfection with dominant negative mutants of ERK2 ({delta}ERK) and JNK ({delta}JNK), and siRNAs for MEK1, p42 and JNK2. TNF-{alpha}-stimulated phosphorylation of p42/p44 MAPK and JNKmore » were attenuated by pretreatment with the inhibitors U0126 and SP600125 or transfection with dominant negative mutants of {delta}ERK and {delta}JNK. Furthermore, the involvement of NF-{kappa}B in TNF-{alpha}-induced MMP-9 production was consistent with that TNF-{alpha}-stimulated degradation of I{kappa}B-{alpha} and translocation of NF-{kappa}B into the nucleus which were blocked by helenalin, but not by U0126 and SP600125, revealed by immunofluorescence staining. The regulation of MMP-9 gene transcription by MAPKs and NF-{kappa}B was further confirmed by gene luciferase activity assay. MMP-9 promoter activity was enhanced by TNF-{alpha} in A549 cells transfected with wild-type MMP-9-Luc, which was inhibited by helenalin, U0126, or SP600125. In contrast, TNF-{alpha}-stimulated MMP-9 luciferase activity was totally lost in cells transfected with mutant-NF-{kappa}B MMP-9-luc. Moreover, pretreatment with actinomycin D and cycloheximide attenuated TNF-{alpha}-induced MMP-9 expression. These results suggest that in A549 cells, phosphorylation of p42/p44 MAPK, JNK, and transactivation of NF-{kappa}B are essential for TNF-{alpha}-induced MMP-9 gene expression.« less

  13. Regulation of B7.1 costimulatory molecule is mediated by the IFN regulatory factor-7 through the activation of JNK in lipopolysaccharide-stimulated human monocytic cells.

    PubMed

    Lim, Wilfred; Gee, Katrina; Mishra, Sasmita; Kumar, Ashok

    2005-11-01

    The engagement of CD28 or CTLA-4 with B7.1 provides the essential second costimulatory signal that regulates the development of immune responses, including T cell activation, differentiation, and induction of peripheral tolerance. The signaling molecules and the transcription factors involved in B7.1 regulation are poorly understood. In this study we investigated the role of MAPKs in the regulation of LPS-induced B7.1 expression in human monocytes and the promonocytic THP-1 cells. Our results show that LPS-induced B7.1 expression in monocytic cells did not involve the activation of either p38 or ERKs. Using the JNK-specific inhibitor SP600125, small interfering RNAs specific for JNK1 and JNK2, and agents such as dexamethasone that inhibit JNK activation, we determined that LPS-induced B7.1 expression was regulated by JNK MAPK in both monocytes and THP-1 cells. In addition, we identified a distinct B7.1-responsive element corresponding to the IFN regulatory factor-7 (IRF-7) binding site in the B7.1 promoter responsible for the regulation of LPS-induced B7.1 transcription. Furthermore, SP600125 and dexamethasone inhibited LPS-induced IRF-7 activity. Taken together, these results suggest that LPS-induced B7.1 transcription in human monocytic cells may be regulated by JNK-mediated activation of the IRF-7 transcription factor.

  14. β1 integrin- and JNK-dependent tumor growth upon hypofractionated radiation.

    PubMed

    Sayeed, Aejaz; Lu, Huimin; Liu, Qin; Deming, David; Duffy, Alexander; McCue, Peter; Dicker, Adam P; Davis, Roger J; Gabrilovich, Dmitry; Rodeck, Ulrich; Altieri, Dario C; Languino, Lucia R

    2016-08-16

    Radiation therapy is an effective cancer treatment modality although tumors invariably become resistant. Using the transgenic adenocarcinoma of mouse prostate (TRAMP) model system, we report that a hypofractionated radiation schedule (10 Gy/day for 5 consecutive days) effectively blocks prostate tumor growth in wild type (β1wt /TRAMP) mice as well as in mice carrying a conditional ablation of β1 integrins in the prostatic epithelium (β1pc-/- /TRAMP). Since JNK is known to be suppressed by β1 integrins and mediates radiation-induced apoptosis, we tested the effect of SP600125, an inhibitor of c-Jun amino-terminal kinase (JNK) in the TRAMP model system. Our results show that SP600125 negates the effect of radiation on tumor growth in β1pc-/- /TRAMP mice and leads to invasive adenocarcinoma. These effects are associated with increased focal adhesion kinase (FAK) expression and phosphorylation in prostate tumors in β1pc-/- /TRAMP mice. In marked contrast, radiation-induced tumor growth suppression, FAK expression and phosphorylation are not altered by SP600125 treatment of β1wt /TRAMP mice. Furthermore, we have reported earlier that abrogation of insulin-like growth factor receptor (IGF-IR) in prostate cancer cells enhances the sensitivity to radiation. Here we further explore the β1/IGF-IR crosstalk and report that β1 integrins promote cell proliferation partly by enhancing the expression of IGF-IR. In conclusion, we demonstrate that β1 integrin-mediated inhibition of JNK signaling modulates tumor growth rate upon hypofractionated radiation.

  15. Sphingosylphosphorylcholine promotes the differentiation of resident Sca-1 positive cardiac stem cells to cardiomyocytes through lipid raft/JNK/STAT3 and β-catenin signaling pathways.

    PubMed

    Li, Wenjing; Liu, Honghong; Liu, Pingping; Yin, Deling; Zhang, Shangli; Zhao, Jing

    2016-07-01

    Resident cardiac Sca-1-positive (+) stem cells may differentiate into cardiomyocytes to improve the function of damaged hearts. However, little is known about the inducers and molecular mechanisms underlying the myogenic conversion of Sca-1(+) stem cells. Here we report that sphingosylphosphorylcholine (SPC), a naturally occurring bioactive lipid, induces the myogenic conversion of Sca-1(+) stem cells, as evidenced by the increased expression of cardiac transcription factors (Nkx2.5 and GATA4), structural proteins (cardiac Troponin T), transcriptional enhancer (Mef2c) and GATA4 nucleus translocation. First, SPC activated JNK and STAT3, and the JNK inhibitor SP600125 or STAT3 inhibitor stattic impaired the SPC-induced expression of cardiac transcription factors and GATA4 nucleus translocation, which suggests that JNK and STAT3 participated in SPC-promoted cardiac differentiation. Moreover, STAT3 activation was inhibited by SP600125, whereas JNK was inhibited by β-cyclodextrin as a lipid raft breaker, which indicates a lipid raft/JNK/STAT3 pathway involved in SPC-induced myogenic transition. β-Catenin, degraded by activated GSK3β, was inhibited by SPC. Furthermore, GSK3β inhibitors weakened but the β-catenin inhibitor promoted SPC-induced differentiation. We found no crosstalk between the lipid raft/JNK/STAT3 and β-catenin pathway. Our study describes a lipid, SPC, as an endogenic inducer of myogenic conversion in Sca-1(+) stem cells with low toxicity and high efficiency for uptake. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. c-Jun N-terminal kinase modulates oxidant stress and peroxynitrite formation independent of inducible nitric oxide synthase in acetaminophen hepatotoxicity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Saito, Chieko; Lemasters, John J.; Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425

    Acetaminophen (APAP) overdose, which causes liver injury in animals and humans, activates c-jun N-terminal kinase (JNK). Although it was shown that the JNK inhibitor SP600125 effectively reduced APAP hepatotoxicity, the mechanisms of protection remain unclear. C57Bl/6 mice were treated with 10 mg/kg SP600125 or vehicle (8% dimethylsulfoxide) 1 h before 600 mg/kg APAP administration. APAP time-dependently induced JNK activation (detected by JNK phosphorylation). SP600125, but not the vehicle, reduced JNK activation, attenuated mitochondrial Bax translocation and prevented the mitochondrial release of apoptosis-inducing factor at 4-12 h. Nuclear DNA fragmentation, nitrotyrosine staining, tissue GSSG levels and liver injury (plasma ALT releasemore » and necrosis) were partially attenuated by the vehicle (- 65%) and completely eliminated by SP600125 (- 98%) at 6 and 12 h. Furthermore, SP600125 attenuated the increase of inducible nitric oxide synthase (iNOS) mRNA and protein. However, APAP did not enhance plasma nitrite + nitrate levels (NO formation); SP600125 had no effect on this parameter. The iNOS inhibitor L-NIL did not reduce NO formation or injury after APAP but prevented NO formation caused by endotoxin. Since SP600125 completely eliminated the increase in hepatic GSSG levels, an indicator of mitochondrial oxidant stress, it is concluded that the inhibition of peroxynitrite was mainly caused by reduced superoxide formation. Our data suggest that the JNK inhibitor SP600125 protects against APAP-induced liver injury in part by attenuation of mitochondrial Bax translocation but mainly by preventing mitochondrial oxidant stress and peroxynitrite formation and thereby preventing the mitochondrial permeability transition pore opening, a key event in APAP-induced cell necrosis.« less

  17. HCV upregulates Bim through the ROS/JNK signalling pathway, leading to Bax-mediated apoptosis.

    PubMed

    Deng, Lin; Chen, Ming; Tanaka, Motofumi; Ku, Yonson; Itoh, Tomoo; Shoji, Ikuo; Hotta, Hak

    2015-09-01

    We previously reported that hepatitis C virus (HCV) infection induces Bax-triggered, mitochondrion-mediated apoptosis by using the HCV J6/JFH1 strain and Huh-7.5 cells. However, it was still unclear how HCV-induced Bax activation. In this study, we showed that the HCV-induced activation and mitochondrial accumulation of Bax were significantly attenuated by treatment with a general antioxidant, N-acetyl cysteine (NAC), or a specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, with the result suggesting that the reactive oxygen species (ROS)/JNK signalling pathway is upstream of Bax activation in HCV-induced apoptosis. We also demonstrated that HCV infection transcriptionally activated the gene for the pro-apoptotic protein Bim and the protein expression of three major splice variants of Bim (BimEL, BimL and BimS). The HCV-induced increase in the Bim mRNA and protein levels was significantly counteracted by treatment with NAC or SP600125, suggesting that the ROS/JNK signalling pathway is involved in Bim upregulation. Moreover, HCV infection led to a marked accumulation of Bim on the mitochondria to facilitate its interaction with Bax. On the other hand, downregulation of Bim by siRNA (small interfering RNA) significantly prevented HCV-mediated activation of Bax and caspase 3. Taken together, these observations suggest that HCV-induced ROS/JNK signalling transcriptionally activates Bim expression, which leads to Bax activation and apoptosis induction.

  18. PI3-K/Akt/JNK/NF-κB is essential for MMP-9 expression and outgrowth in human limbal epithelial cells on intact amniotic membrane.

    PubMed

    Cheng, Ching-Yi; Hsieh, Hsi-Lung; Hsiao, Li-Der; Yang, Chuen-Mao

    2012-07-01

    Matrix metalloproteinase-9 (MMP-9) plays an important role in the outgrowth of expanded human limbal epithelial cells on intact amniotic membranes (AM). The mechanisms of MMP-9 expression and cell outgrowth remain unknown. Here, we demonstrated that MMP-9 is preferentially expressed at the leading edge of limbal epithelial outgrowth. Treatment with the inhibitors of PI3-K (LY294002), Akt (SH-5), MEK1/2 (U0126), and JNK1/2 (SP600125) attenuated the outgrowth area, indicating that PI3-K/Akt, p42/p44 MAPK, and JNK1/2 are involved in the outgrowth of intact AM-expanded limbal epithelial cells. However, MMP-9 expression at both transcriptional and translational levels was attenuated by treatment with SP600125, LY294002, or SH-5, not by U0126 and SB202190, suggesting that JNK1/2 and PI3-K/Akt participate in MMP-9 expression. Moreover, NF-κB phosphorylation and nuclear translocation was especially noted at the leading edge, which was attenuated by treatment with SP600125 or LY294002. Helenalin, a selective NF-κB inhibitor, reduced both the limbal epithelial outgrowth and MMP-9 expression. Finally, the data reveal that PI3-K/Akt is an upstream component of the JNK1/2 pathway in MMP-9 expression. Thus, both MAPKs and PI3-K/Akt are required for limbal epithelial outgrowth on intact AM, only the PI3-K/Akt/JNK is essential for MMP-9 expression mediated through activation of transcriptional factor NF-κB in this model. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. JNK1 Mediates Lipopolysaccharide-Induced CD14 and SR-AI Expression and Macrophage Foam Cell Formation.

    PubMed

    An, Dong; Hao, Feng; Hu, Chen; Kong, Wei; Xu, Xuemin; Cui, Mei-Zhen

    2017-01-01

    Foam cell formation is the key process in the development of atherosclerosis. The uptake of oxidized low-density lipoprotein (oxLDL) converts macrophages into foam cells. We recently reported that lipopolysaccharide (LPS)-induced foam cell formation is regulated by CD14 and scavenger receptor AI (SR-AI). In this study, we employed pharmaceutical and gene knockdown approaches to determine the upstream molecular mediators, which control LPS-induced foam cell formation. Our results demonstrated that the specific c-Jun N-terminal kinase (JNK) pathway inhibitor, SP600125, but neither the specific inhibitor of extracellular signaling-regulated kinase (ERK) kinase MEK1/2, U0126, nor the specific inhibitor of p38 MAPK, SB203580, significantly blocks LPS-induced oxLDL uptake, suggesting that the JNK pathway is the upstream mediator of LPS-induced oxLDL uptake/foam cell formation. To address whether JNK pathway mediates LPS-induced oxLDL uptake is due to JNK pathway-regulated CD14 and SR-AI expression, we assessed whether the pharmaceutical inhibitor of JNK influences LPS-induced expression of CD14 and SR-AI. Our results indicate that JNK pathway mediates LPS-induced CD14 and SR-AI expression. To conclusively address the isoform role of JNK family, we depleted JNK isoforms using the JNK isoform-specific siRNA. Our data showed that the depletion of JNK1, but not JNK2 blocked LPS-induced CD14/SR-AI expression and foam cell formation. Taken together, our results reveal for the first time that JNK1 is the key mediator of LPS-induced CD14 and SR-AI expression in macrophages, leading to LPS-induced oxLDL uptake/foam cell formation. We conclude that the novel JNK1/CD14/SR-AI pathway controls macrophage oxLDL uptake/foam cell formation.

  20. Phosphorylation of Ribosomal Protein S6 Kinase 1 at Thr421/Ser424 and Dephosphorylation at Thr389 Regulates SP600125-Induced Polyploidization of Megakaryocytic Cell Lines

    PubMed Central

    Lin, Di; Zhao, Yong-Shan; Liu, Shuo; Xing, Si-Ning; Zhao, Song; Chen, Cong-Qin; Jiang, Zhi-Ming; Pu, Fei-Fei; Cao, Jian-Ping; Ma, Dong-Chu

    2014-01-01

    Megakaryocytes (MKs) are one of the few cell types that become polyploid; however, the mechanisms by which these cells are designated to become polyploid are not fully understood. In this investigation, we successfully established two relatively synchronous polyploid cell models by inducing Dami and CMK cells with SP600125. We found that SP600125 induced the polyploidization of Dami and CMK cells, concomitant with the phosphorylation of ribosomal protein S6 kinase 1 (S6K1) at Thr421/Ser424 and dephosphorylation at Thr389. The polyploidization was partially blocked by H-89, a cAMP-dependent protein kinase (PKA) inhibitor, through direct binding to S6K1, leading to dephosphorylation at Thr421/Ser424 and phosphorylation at Thr389, independent of PKA. Overexpression of a rapamycin-resistant mutant of S6K1 further enhanced the inhibitory effect of LY294002 on the SP600125-induced polyploidization of Dami and CMK cells. SP600125 also induced the polyploidization of Meg-01 cells, which are derived from a patient with chronic myelogenous leukemia, without causing a significant change in S6K1 phosphorylation. Additionally, SP600125 induced the polyploidization of HEL cells, which are derived from a patient with erythroleukemia, and phosphorylation at Thr389 of S6K1 was detected. However, the polyploidization of both Meg-01 cells and HEL cells as a result of SP600125 treatment was lower than that of SP600125-induced Dami and CMK cells, and it was not blocked by H-89 despite the increased phosphorylation of S6K1 at Thr389 in both cell lines in response to H-89. Given that the Dami and CMK cell lines were derived from patients with acute megakaryocytic leukemia (AMKL) and expressed high levels of platelet-specific antigens, our data suggested that SP600125-induced polyploidization is cell-type specific, that these cell lines were more differentiated, and that phosphorylation at Thr421/Ser424 and dephosphorylation at Thr389 of S6K1 may play an important role in the SP600125

  1. Phosphorylation of ribosomal protein S6 kinase 1 at Thr421/Ser424 and dephosphorylation at Thr389 regulates SP600125-induced polyploidization of megakaryocytic cell lines.

    PubMed

    Li, Chang-Ling; Yang, Jin-Gang; Lin, Di; Zhao, Yong-Shan; Liu, Shuo; Xing, Si-Ning; Zhao, Song; Chen, Cong-Qin; Jiang, Zhi-Ming; Pu, Fei-Fei; Cao, Jian-Ping; Ma, Dong-Chu

    2014-01-01

    Megakaryocytes (MKs) are one of the few cell types that become polyploid; however, the mechanisms by which these cells are designated to become polyploid are not fully understood. In this investigation, we successfully established two relatively synchronous polyploid cell models by inducing Dami and CMK cells with SP600125. We found that SP600125 induced the polyploidization of Dami and CMK cells, concomitant with the phosphorylation of ribosomal protein S6 kinase 1 (S6K1) at Thr421/Ser424 and dephosphorylation at Thr389. The polyploidization was partially blocked by H-89, a cAMP-dependent protein kinase (PKA) inhibitor, through direct binding to S6K1, leading to dephosphorylation at Thr421/Ser424 and phosphorylation at Thr389, independent of PKA. Overexpression of a rapamycin-resistant mutant of S6K1 further enhanced the inhibitory effect of LY294002 on the SP600125-induced polyploidization of Dami and CMK cells. SP600125 also induced the polyploidization of Meg-01 cells, which are derived from a patient with chronic myelogenous leukemia, without causing a significant change in S6K1 phosphorylation. Additionally, SP600125 induced the polyploidization of HEL cells, which are derived from a patient with erythroleukemia, and phosphorylation at Thr389 of S6K1 was detected. However, the polyploidization of both Meg-01 cells and HEL cells as a result of SP600125 treatment was lower than that of SP600125-induced Dami and CMK cells, and it was not blocked by H-89 despite the increased phosphorylation of S6K1 at Thr389 in both cell lines in response to H-89. Given that the Dami and CMK cell lines were derived from patients with acute megakaryocytic leukemia (AMKL) and expressed high levels of platelet-specific antigens, our data suggested that SP600125-induced polyploidization is cell-type specific, that these cell lines were more differentiated, and that phosphorylation at Thr421/Ser424 and dephosphorylation at Thr389 of S6K1 may play an important role in the SP600125

  2. DISTINCT FUNCTIONS OF JNK AND C-JUN IN OXIDANT-INDUCED HEPATOCYTE DEATH

    PubMed Central

    Amir, Muhammad; Liu, Kun; Zhao, Enpeng; Czaja, Mark J.

    2013-01-01

    Overactivation of c-Jun N-terminal kinase (JNK)/c-Jun signaling is a central mechanism of hepatocyte injury and death including that from oxidative stress. However, the functions of JNK and c-Jun are still unclear, and this pathway also inhibits hepatocyte death. Previous studies of menadione-induced oxidant stress demonstrated that toxicity resulted from sustained JNK/c-Jun activation as death was blocked by the c-Jun dominant negative TAM67. To further delineate the function of JNK/c-Jun signaling in hepatocyte injury from oxidant stress, the effects of direct JNK inhibition on menadione-induced death were examined. In contrast to the inhibitory effect of TAM67, pharmacological JNK inhibition by SP600125 sensitized the rat hepatocyte cell line RALA255-10G to death from menadione. SP600125 similarly sensitized mouse primary hepatocytes to menadione toxicity. Death from SP600125/menadione was c-Jun dependent as it was blocked by TAM67, but independent of c-Jun phosphorylation. Death occurred by apoptosis and necrosis and activation of the mitochondrial death pathway. Short hairpin RNA knockdowns of total JNK or JNK2 sensitized to death from menadione, whereas a jnk1 knockdown was protective. Jnk2 null mouse primary hepatocytes were also sensitized to menadione death. JNK inhibition magnified decreases in cellular ATP content and β-oxidation induced by menadione. This effect mediated cell death as chemical inhibition of β-oxidation also sensitized cells to death from menadione, and supplementation with the β-oxidation substrate oleate blocked death. Components of the JNK/c-Jun signaling pathway have opposing functions in hepatocyte oxidant stress with JNK2 mediating resistance to cell death and c-Jun promoting death. PMID:22644775

  3. Expression and proliferation profiles of PKC, JNK and p38MAPK in physiologically stretched human bladder smooth muscle cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wazir, Romel; Luo, De-Yi; Dai, Yi

    2013-08-30

    Highlights: •Stretch induces proliferation in human bladder smooth muscle cells (HBSMC). •5% Equibiaxial elongation produces maximum proliferation. •Physiologic stretch decreases apoptotic cell death. •PKC is involved in functional modulation of bladder. •JNK and p38 are not involved in proliferating HBSMC. -- Abstract: Objective: To determine protein kinase C (PKC), c-Jun NH2-Terminal Kinase (JNK) and P38 mitogen-activated protein kinases (p38MAPK) expression levels and effects of their respective inhibitors on proliferation of human bladder smooth muscle cells (HBSMCs) when physiologically stretched in vitro. Materials and methods: HBSMCs were grown on silicone membrane and stretch was applied under varying conditions; (equibiaxial elongation: 2.5%,more » 5%, 10%, 15%, 20%, 25%), (frequency: 0.05, 0.1, 0.2, 0.5, 1 Hz). Optimal physiological stretch was established by assessing proliferation with 5-Bromo-2-deoxyuridine (BrdU) assay and flow cytometry. PKC, JNK and p38 expression levels were analyzed by Western blot. Specificity was maintained by employing specific inhibitors; (GF109203X for PKC, SP600125 for JNK and SB203580 for p38MAPK), in some experiments. Results: Optimum proliferation was observed at 5% equibiaxial stretch (BrdU: 0.837 ± 0.026 (control) to 1.462 ± 0.023)%, (P < 0.05) and apoptotic cell death rate decreased from 16.4 ± 0.21% (control) to 4.5 ± 0.13% (P < 0.05) applied at 0.1 Hz. Expression of PKC was upregulated with slight increase in JNK and no change in p38MAPK after application of stretch. Inhibition had effects on proliferation (1.075 ± 0.024, P < 0.05 GF109203X); (1.418 ± 0.021, P > 0.05 SP600125) and (1.461 ± 0.01, P > 0.05 SB203580). These findings show that mechanical stretch can promote magnitude-dependent proliferative modulation through PKC and possibly JNK but not via p38MAPK in hBSMCs.« less

  4. Inhibition of c-Jun N-terminal kinase activation reverses Alzheimer disease phenotypes in APPswe/PS1dE9 mice.

    PubMed

    Zhou, Qiong; Wang, Man; Du, Ying; Zhang, Wei; Bai, Miao; Zhang, Zhuo; Li, Zhuyi; Miao, Jianting

    2015-04-01

    Growing evidence indicates that the activation of c-Jun N-terminal kinase (JNK) is implicated in the multiple major pathological features of Alzheimer disease (AD). However, whether specific inhibition of JNK activation could prevent disease progression in adult transgenic AD models at moderate stage remains unknown. Here we first investigated the potential disease-modifying therapeutic effect of systemic administration of SP600125, a small-molecule JNK-specific inhibitor, in middle-aged APPswe/PS1dE9 mice. Using behavioral, histological, and biochemical methods, outcomes of SP600125 treatment on neuropathology and cognitive deficits were studied in APPswe/PS1dE9 mice. Compared with vehicle-treated APPswe/PS1dE9 mice, chronic treatment of SP600125 for 12 weeks potently inhibited JNK activation, which resulted in a marked improvement of behavioral measures of cognitive deficits and a dramatic reduction in amyloid plaque burden, β-amyloid production, tau hyperphosphorylation, inflammatory responses, and synaptic loss in these transgenic animals. In particular, we found that SP600125 treatment strongly promoted nonamyloidogenic amyloid precursor protein (APP) processing and inhibited amyloidogenic APP processing via regulating APP-cleavage secretase expression (ie, ADAM10, BACE1, and PS1) in APPswe/PS1dE9 mice. Our findings demonstrate that chronic SP600125 treatment is powerfully effective in slowing down disease progression by markedly reducing multiple pathological features and ameliorating cognitive deficits associated with AD. This study highlights the concept that active JNK actually contributes to the development of the disease, and provides critical preclinical evidence that specific inhibition of JNK activation by SP600125 treatment may be a novel promising disease-modifying therapeutic strategy for the treatment of AD. © 2015 American Neurological Association.

  5. Gefitinib enhances human colon cancer cells to TRAIL-induced apoptosis of via autophagy- and JNK-mediated death receptors upregulation.

    PubMed

    Chen, Lei; Meng, Yue; Guo, Xiaoqing; Sheng, Xiaotong; Tai, Guihua; Zhang, Fenglei; Cheng, Hairong; Zhou, Yifa

    2016-11-01

    Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a potent cancer cell-specific apoptosis-inducing cytokine with little toxicity to most normal cells. Here, we report that gefitinib and TRAIL in combination produce a potent synergistic effect on TRAIL-sensitive human colon cancer HCT116 cells and an additive effect on TRAIL-resistant HT-29 cells. Interestingly, gefitinib increases the expression of cell surface receptors DR4 and DR5, possibly explaining the synergistic effect. Knockdown of DR4 and DR5 by siRNA significantly decreases gefitinib- and TRAIL-mediated cell apoptosis, supporting this idea. Because the inhibition of gefitinib-induced autophagy by 3-MA significantly decreases DR4 and DR5 upregulation, as well as reduces gefitinib- and TRAIL-induced apoptosis, we conclude that death receptor upregulation is autophagy mediated. Furthermore, our results indicate that death receptor expression may also be regulated by JNK activation, because pre-treatment of cells with JNK inhibitor SP600125 significantly decreases gefitinib-induced death receptor upregulation. Interestingly, SP600125 also inhibits the expression CHOP, yet CHOP has no impact on death receptor expressions. We also find here that phosphorylation of Akt and ERK might also be required for TRAIL sensitization. In summary, our results indicate that gefitinib effectively enhances TRAIL-induced apoptosis, likely via autophagy and JNK- mediated death receptor expression and phosphorylation of Akt and ERK.

  6. [Effect of Acupuncture Intervention on c-jun N-terminal Kinase Signaling in the Hippocampus in Rats with Forced Swimming Stress].

    PubMed

    Guo, Yu; Xu, Ke; Bao, Wu-ye; Wang, Yu; Zhang, Xu-hui; Xu, Ming-min; Yu, Miao; Zhang, Chun-tao; Zhao, Bing-cong; Wu, Ji-hong; Tu, Ya

    2016-02-01

    To observe the effect of acupuncture on c-jun N-terminal Kinase (JNK) signaling in the hippocampus in rats with forced-swimming stress, so as to reveal its underlying mechanism in relieving depression-like motor response. Forty-eight Sprague-Dawley rats were randomly divided into 8 groups as control, control + JNK inhibitor (SP 600125) , model, model + SP 600125, acupuncture, acupuncture + SP 600125, Fluoxetine (an anti-depressant) , and Fluoxetine + SP 600125 (n = 6 in each group). The depression-like behavior (immobility) model was established by forcing the rat to swim in a glass-cylinder and solitary raise. Acupuncture stimulation was applied to "Baihui" (GV-20) and "Yintang" (GV 29) for 20 min before forced swimming and once again 24 h later.. The rats of the Fluoxetine and Fluoxetine+ SP 600125 groups were treated by intragastric administration of fluoxetine 10 mL (1.8 mg)/kg before forced swimming and once again 24 h thereafter. The rats of the model + SP 600125 and acupuncture + SP 600125 groups were treated by intraperitoneal injection of SP 600125 (10 mg/kg) 90 min before forced swimming and 30 min before acupuncture intervention, respectively. The immobility duration of rats in the water glass-cylinder was used to assess their depression-like behavior response. The expression levels of protein kinase kinase 4 (MKK 4), MKK 7, JNK, and phosphorylated JNK (p-JNK) in the hippocampus were detected by Western blot. Compared to the control group, the duration of immobility, and the expression levels of hippocampal MKK 4, MKK 7, and p-JNK proteins were significantly increased in the model group (P < 0.01). While in comparison with the model group, the duration of immobility in the model + SP 600125, acupuncture, acupuncture + SP 600125, Fluoxetine and Fluoxetine + SP 600125 groups, the expression levels of hippocampal MKK 4 and MKK 7 proteins in the Fluoxetine + SP 600125 group, and those of p-JNK protein in the acupuncture, acupuncture + SP 600125, model + SP

  7. Induction apoptosis of luteolin in human hepatoma HepG2 cells involving mitochondria translocation of Bax/Bak and activation of JNK

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, H.-J.; Wang, C.-J.; Kuo, H.-C.

    2005-03-01

    Since hepatocellular carcinoma remains a major challenging clinical problem in many parts of the world including Eastern Asia and Southern Africa, it is imperative to develop more effective chemopreventive and chemotherapy agents. Herein, we present an investigation regarding the anticancer potential of luteolin, a natural flavonoid, and the mechanism of its action in human hepatoma HepG2 cells. Using DNA fragmentation assay and nuclear staining assay, it showed that luteolin induced apoptosis of HepG2 cells. Luteolin induced the cytosolic release of cytochrome c and activated CPP32. We found that Bax and Bak translocated to mitochondria apparently, whereas Fas ligand (FasL) wasmore » unchanged after a treatment with luteolin for 3 h. In addition, it showed that c-Jun NH{sub 2}-terminal kinase (JNK) was activated after the treatment of luteolin for 3-12 h. Further investigation showed that a specific JNK inhibitor, SP600125, reduced the activation of CPP 32, the mitochondrial translocation of Bax, as well as the cytosolic release of cytochrome c that induced by luteolin. Finally, the apoptosis induced by luteolin was suppressed by a pretreatment with SP600125 via evaluating annexin V-FITC binding assay. These data suggest that luteolin induced apoptosis via mechanisms involving mitochondria translocation of Bax/Bak and activation of JNK.« less

  8. Ultra Fine Particles from Diesel Engines Induce Vascular Oxidative Stress via JNK Activation

    PubMed Central

    Li, Rongsong; Ning, Zhi; Cui, Jeffery; Khalsa, Bhavraj; Ai, Lisong; Takabe, Wakako; Beebe, Tyler; Majumdar, Rohit; Sioutas, Constantinos; Hsiai, Tzung

    2011-01-01

    Exposure of particulate air pollution is linked to increased incidences of cardiovascular diseases. Ambient ultra fine particles (UFP) from diesel vehicle engines have been shown to be pro-atherogenic in apoE knockout mice and may constitute a major cardiovascular risk in humans. We posited that circulating nano-sized particles from traffic pollution sources induced vascular oxidative stress via JNK activation in endothelial cells. Diesel UFP were collected from a 1998 Kenworth truck. Intra-cellular superoxide assay revealed that these UFP dose-dependently induced superoxide (O2·-) production in human aortic endothelial cells (HAEC). Flow cytometry (FACS) showed that UFP increased MitoSOX Red intensity specific for mitochondrial superoxide. Protein carbonyl content is increased by UFP as an indication of vascular oxidative stress. UFP also up-regulated hemeoxygenase-1 (HO-1) and tissue factor (TF) mRNA expression, and pre-treatment with antioxidant, N-acetyl cysteine (NAC), significantly decreased their expression. Furthermore, UFP transiently activated JNK in HAEC. Treatment with JNK inhibitor SP600125 and silencing of both JNK1 and JNK2 with siRNA inhibited UFP stimulated O2·- production and mRNA expression of HO-1 and TF. Our findings suggest that JNK activation play an important role in UFP-induced oxidative stress and stress response gene expression. PMID:19154785

  9. Asthmatic airway smooth muscle CXCL10 production: mitogen-activated protein kinase JNK involvement

    PubMed Central

    Alrashdan, Yazan A.; Alkhouri, Hatem; Chen, Emily; Lalor, Daniel J.; Poniris, Maree; Henness, Sheridan; Brightling, Christopher E.; Burgess, Janette K.; Armour, Carol L.; Ammit, Alaina J.

    2012-01-01

    CXCL10 (IP10) is involved in mast cell migration to airway smooth muscle (ASM) bundles in asthma. We aimed to investigate the role of cytokine-induced MAPK activation in CXCL10 production by ASM cells from people with and without asthma. Confluent growth-arrested ASM cells were treated with inhibitors of the MAPKs ERK, p38, and JNK and transcription factor NF-κB, or vehicle, and stimulated with IL-1β, TNF-α, or IFN-γ, alone or combined (cytomix). CXCL10 mRNA and protein, JNK, NF-κB p65 phosphorylation, and Iκ-Bα protein degradation were assessed using real-time PCR, ELISA, and immunoblotting, respectively. Cytomix, IL-1β, and TNF-α induced CXCL10 mRNA expression more rapidly in asthmatic than nonasthmatic ASM cells. IL-1β and/or TNF-α combined with IFN-γ synergistically increased asthmatic ASM cell CXCL10 release. Inhibitor effects were similar in asthmatic and nonasthmatic cells, but cytomix-induced release was least affected, with only JNK and NF-κB inhibitors halving it. Notably, JNK phosphorylation was markedly less in asthmatic compared with nonasthmatic cells. However, in both, the JNK inhibitor SP600125 reduced JNK phosphorylation and CXCL10 mRNA levels but did not affect CXCL10 mRNA stability or Iκ-Bα degradation. Together, the JNK and NF-κB inhibitors completely inhibited their CXCL10 release. We concluded that, in asthmatic compared with nonasthmatic ASM cells, JNK activation was reduced and CXCL10 gene expression was more rapid following cytomix stimulation. However, in both, JNK activation did not regulate early events leading to NF-κB activation. Thus JNK and NF-κB provide independent therapeutic targets for limiting CXCL10 production and mast cell migration to the ASM in asthma. PMID:22387292

  10. Asthmatic airway smooth muscle CXCL10 production: mitogen-activated protein kinase JNK involvement.

    PubMed

    Alrashdan, Yazan A; Alkhouri, Hatem; Chen, Emily; Lalor, Daniel J; Poniris, Maree; Henness, Sheridan; Brightling, Christopher E; Burgess, Janette K; Armour, Carol L; Ammit, Alaina J; Hughes, J Margaret

    2012-05-15

    CXCL10 (IP10) is involved in mast cell migration to airway smooth muscle (ASM) bundles in asthma. We aimed to investigate the role of cytokine-induced MAPK activation in CXCL10 production by ASM cells from people with and without asthma. Confluent growth-arrested ASM cells were treated with inhibitors of the MAPKs ERK, p38, and JNK and transcription factor NF-κB, or vehicle, and stimulated with IL-1β, TNF-α, or IFN-γ, alone or combined (cytomix). CXCL10 mRNA and protein, JNK, NF-κB p65 phosphorylation, and Iκ-Bα protein degradation were assessed using real-time PCR, ELISA, and immunoblotting, respectively. Cytomix, IL-1β, and TNF-α induced CXCL10 mRNA expression more rapidly in asthmatic than nonasthmatic ASM cells. IL-1β and/or TNF-α combined with IFN-γ synergistically increased asthmatic ASM cell CXCL10 release. Inhibitor effects were similar in asthmatic and nonasthmatic cells, but cytomix-induced release was least affected, with only JNK and NF-κB inhibitors halving it. Notably, JNK phosphorylation was markedly less in asthmatic compared with nonasthmatic cells. However, in both, the JNK inhibitor SP600125 reduced JNK phosphorylation and CXCL10 mRNA levels but did not affect CXCL10 mRNA stability or Iκ-Bα degradation. Together, the JNK and NF-κB inhibitors completely inhibited their CXCL10 release. We concluded that, in asthmatic compared with nonasthmatic ASM cells, JNK activation was reduced and CXCL10 gene expression was more rapid following cytomix stimulation. However, in both, JNK activation did not regulate early events leading to NF-κB activation. Thus JNK and NF-κB provide independent therapeutic targets for limiting CXCL10 production and mast cell migration to the ASM in asthma.

  11. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nguyen Ngoc, Tam Dan; Son, Young-Ok; Lim, Shin-Saeng

    2012-03-15

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaFmore » induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53

  12. JNK and NADPH Oxidase Involved in Fluoride-Induced Oxidative Stress in BV-2 Microglia Cells

    PubMed Central

    Yan, Ling; Liu, Shengnan; Wang, Chen; Wang, Fei; Song, Yingli; Yan, Nan; Xi, Shuhua; Liu, Ziyou; Sun, Guifan

    2013-01-01

    Excessive fluoride may cause central nervous system (CNS) dysfunction, and oxidative stress is a recognized mode of action of fluoride toxicity. In CNS, activated microglial cells can release more reactive oxygen species (ROS), and NADPH oxidase (NOX) is the major enzyme for the production of extracellular superoxide in microglia. ROS have been characterized as an important secondary messenger and modulator for various mammalian intracellular signaling pathways, including the MAPK pathways. In this study we examined ROS production and TNF-α, IL-1β inflammatory cytokines releasing, and the expression of MAPKs in BV-2 microglia cells treated with fluoride. We found that fluoride increased JNK phosphorylation level of BV-2 cells and pretreatment with JNK inhibitor SP600125 markedly reduced the levels of intracellular O2 ·− and NO. NOX inhibitor apocynin and iNOS inhibitor SMT dramatically decreased NaF-induced ROS and NO generations, respectively. Antioxidant melatonin (MEL) resulted in a reduction in JNK phosphorylation in fluoride-stimulated BV-2 microglia. The results confirmed that NOX and iNOS played an important role in fluoride inducing oxidative stress and NO production and JNK took part in the oxidative stress induced by fluoride and meanwhile also could be activated by ROS in fluoride-treated BV-2 cells. PMID:24072958

  13. Function-specific intracellular signaling pathways downstream of heparin-binding EGF-like growth factor utilized by human trophoblasts.

    PubMed

    Jessmon, Philip; Kilburn, Brian A; Romero, Roberto; Leach, Richard E; Armant, D Randall

    2010-05-01

    Heparin-binding EGF-like growth factor (HBEGF) is expressed by trophoblast cells throughout gestation. First-trimester cytotrophoblast cells are protected from hypoxia-induced apoptosis because of the accumulation of HBEGF through a posttranscriptional autocrine mechanism. Exogenous application of HBEGF is cytoprotective in a hypoxia/reoxygenation (H/R) injury model and initiates trophoblast extravillous differentiation to an invasive phenotype. The downstream signaling pathways induced by HBEGF that mediate these various cellular activities were identified using two human first-trimester cytotrophoblast cell lines, HTR-8/SVneo and SW.71, with similar results. Recombinant HBEGF (1 nM) induced transient phosphorylation of MAPK3/1 (ERK), MAPK14 (p38), and AKT within 15 min and JNK after 1-2 h. To determine which downstream pathways regulate the various functions of HBEGF, cells were treated with specific inhibitors of the ERK upstream regulator MEK (U0126), the AKT upstream regulator phosphoinositide-3 (PI3)-kinase (LY294002), MAPK14 (SB203580), and JNK (SP600125), as well as with inactive structural analogues. Only SB203580 specifically prevented HBEGF-mediated rescue during H/R, while each inhibitor attenuated HBEGF-stimulated cell migration. Accumulation of HBEGF at reduced oxygen was blocked only by a combination of U0126, SB203580, and SP600125. We conclude that HBEGF advances trophoblast extravillous differentiation through coordinate activation of PI3 kinase, ERK, MAPK14, and JNK, while only MAPK14 is required for its antiapoptotic activity. Additionally, hypoxia induces an autocrine increase in HBEGF protein levels through MAPK14, JNK or ERK. These experiments reveal a complexity of the intracellular signaling circuitry that regulates trophoblast functions critical for implantation and placentation.

  14. Fluoride induces oxidative damage and SIRT1/autophagy through ROS-mediated JNK signaling.

    PubMed

    Suzuki, Maiko; Bandoski, Cheryl; Bartlett, John D

    2015-12-01

    Fluoride is an effective caries prophylactic, but at high doses can also be an environmental health hazard. Acute or chronic exposure to high fluoride doses can result in dental enamel and skeletal and soft tissue fluorosis. Dental fluorosis is manifested as mottled, discolored, porous enamel that is susceptible to dental caries. Fluoride induces cell stress, including endoplasmic reticulum stress and oxidative stress, which leads to impairment of ameloblasts responsible for dental enamel formation. Recently we reported that fluoride activates SIRT1 and autophagy as an adaptive response to protect cells from stress. However, it still remains unclear how SIRT1/autophagy is regulated in dental fluorosis. In this study, we demonstrate that fluoride exposure generates reactive oxygen species (ROS) and the resulting oxidative damage is counteracted by SIRT1/autophagy induction through c-Jun N-terminal kinase (JNK) signaling in ameloblasts. In the mouse-ameloblast-derived cell line LS8, fluoride induced ROS, mitochondrial damage including cytochrome-c release, up-regulation of UCP2, attenuation of ATP synthesis, and H2AX phosphorylation (γH2AX), which is a marker of DNA damage. We evaluated the effects of the ROS inhibitor N-acetylcysteine (NAC) and the JNK inhibitor SP600125 on fluoride-induced SIRT1/autophagy activation. NAC decreased fluoride-induced ROS generation and attenuated JNK and c-Jun phosphorylation. NAC decreased SIRT1 phosphorylation and formation of the autophagy marker LC3II, which resulted in an increase in the apoptosis mediators γH2AX and cleaved/activated caspase-3. SP600125 attenuated fluoride-induced SIRT1 phosphorylation, indicating that fluoride activates SIRT1/autophagy via the ROS-mediated JNK pathway. In enamel organs from rats or mice treated with 50, 100, or 125 ppm fluoride for 6 weeks, cytochrome-c release and the DNA damage markers 8-oxoguanine, p-ATM, and γH2AX were increased compared to those in controls (0 ppm fluoride). These

  15. Fluoride induces oxidative damage and SIRT1/autophagy through ROS-mediated JNK signaling

    PubMed Central

    Suzuki, Maiko; Bandoski, Cheryl; Bartlett, John D.

    2015-01-01

    Fluoride is an effective caries prophylactic, but at high doses can also be an environmental health hazard. Acute or chronic exposure to high fluoride doses can result in dental enamel and skeletal and soft tissue fluorosis. Dental fluorosis is manifested as mottled, discolored, porous enamel that is susceptible to dental caries. Fluoride induces cell stress, including endoplasmic reticulum stress and oxidative stress, which leads to impairment of ameloblasts responsible for dental enamel formation. Recently we reported that fluoride activates SIRT1 and autophagy as an adaptive response to protect cells from stress. However, it still remains unclear how SIRT1/autophagy is regulated in dental fluorosis. In this study, we demonstrate that fluoride exposure generates reactive oxygen species (ROS) and the resulting oxidative damage is counteracted by SIRT1/autophagy induction through c-Jun N-terminal kinase (JNK) signaling in ameloblasts. In the mouse-ameloblast-derived cell line LS8, fluoride induced ROS, mitochondrial damage including cytochrome-c release, up-regulation of UCP2, attenuation of ATP synthesis, and H2AX phosphorylation (γH2AX), which is a marker of DNA damage. We evaluated the effects of the ROS inhibitor N-acetylcysteine (NAC) and the JNK inhibitor SP600125 on fluoride-induced SIRT1/autophagy activation. NAC decreased fluoride-induced ROS generation and attenuated JNK and c-Jun phosphorylation. NAC decreased SIRT1 phosphorylation and formation of the autophagy marker LC3II, which resulted in an increase in the apoptosis mediators γH2AX and cleaved/activated caspase-3. SP600125 attenuated fluoride-induced SIRT1 phosphorylation, indicating that fluoride activates SIRT1/autophagy via the ROS-mediated JNK pathway. In enamel organs from rats or mice treated with 50, 100, or 125 ppm fluoride for 6 weeks, cytochrome-c release and the DNA damage markers 8-oxoguanine, p-ATM, and γH2AX were increased compared to those in controls (0 ppm fluoride). These

  16. JNK1 Inhibition Attenuates Hypoxia-Induced Autophagy and Sensitizes to Chemotherapy.

    PubMed

    Vasilevskaya, Irina A; Selvakumaran, Muthu; Roberts, David; O'Dwyer, Peter J

    2016-08-01

    Inhibition of hypoxia-induced stress signaling through JNK potentiates the effects of oxaliplatin. The JNK pathway plays a role in both autophagy and apoptosis; therefore, it was determined how much of the effect of JNK inhibition on oxaliplatin sensitivity is dependent on its effect on autophagy. We studied the impact of JNK isoform downregulation in the HT29 colon adenocarcinoma cell line on hypoxia- and oxaliplatin-induced responses. Electron microscopic analyses demonstrated that both oxaliplatin- and hypoxia-induced formations of autophagosomes were reduced significantly in HT29 cells treated with the JNK inhibitor SP600125. The role of specific JNK isoforms was defined using HT29-derived cell lines stably expressing dominant-negative constructs for JNK1 and JNK2 (HTJ1.3 and HTJ2.2, respectively). These cell lines demonstrated that functional JNK1 is required for hypoxia-induced autophagy and that JNK2 does not substitute for it. Inhibition of autophagy in HTJ1.3 cells also coincided with enhancement of intrinsic apoptosis. Analysis of Bcl2-family proteins revealed hyperphosphorylation of Bcl-XL in the HTJ1.3 cell line, but this did not lead to the expected dissociation from Beclin 1. Consistent with this, knockdown of Bcl-XL in HT29 cells did not significantly affect the induction of autophagy, but abrogated hypoxic resistance to oxaliplatin due to the faster and more robust activation of apoptosis. These data suggest that balance between autophagy and apoptosis is shifted toward apoptosis by downregulation of JNK1, contributing to oxaliplatin sensitization. These findings further support the investigation of JNK inhibition in colorectal cancer treatment. Mol Cancer Res; 14(8); 753-63. ©2016 AACR. ©2016 American Association for Cancer Research.

  17. Cypermethrin Induces Macrophages Death through Cell Cycle Arrest and Oxidative Stress-Mediated JNK/ERK Signaling Regulated Apoptosis

    PubMed Central

    Huang, Fang; Liu, Qiaoyun; Xie, Shujun; Xu, Jian; Huang, Bo; Wu, Yihua; Xia, Dajing

    2016-01-01

    Cypermethrin is one of the most highly effective synthetic pyrethroid insecticides. The toxicity of cypermethrin to the reproductive and nervous systems has been well studied. However, little is known about the toxic effect of cypermethrin on immune cells such as macrophages. Here, we investigated the cytotoxicity of cypermethrin on macrophages and the underlying molecular mechanisms. We found that cypermethrin reduced cell viability and induced apoptosis in RAW 264.7 cells. Cypermethrin also increased reactive oxygen species (ROS) production and DNA damage in a dose-dependent manner. Moreover, cypermethrin-induced G1 cell cycle arrest was associated with an enhanced expression of p21, wild-type p53, and down-regulation of cyclin D1, cyclin E and CDK4. In addition, cypermethrin treatment activated MAPK signal pathways by inducing c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases 1/2 ERK1/2 phosphorylation, and increased the cleaved poly ADP-ribose polymerase (PARP). Further, pretreatment with antioxidant N-acetylcysteine (NAC) effectively abrogated cypermethrin-induced cell cytotoxicity, G1 cell cycle arrest, DNA damage, PARP activity, and JNK and ERK1/2 activation. The specific JNK inhibitor (SP600125) and ERK1/2 inhibitor (PD98059) effectively reversed the phosphorylation level of JNK and ERK1/2, and attenuated the apoptosis. Taken together, these data suggested that cypermethrin caused immune cell death via inducing cell cycle arrest and apoptosis regulated by ROS-mediated JNK/ERK pathway. PMID:27322250

  18. Inhibition of c-Jun NH2-terminal kinase switches Smad3 signaling from oncogenesis to tumor- suppression in rat hepatocellular carcinoma.

    PubMed

    Nagata, Hiromitsu; Hatano, Etsuro; Tada, Masaharu; Murata, Miki; Kitamura, Koji; Asechi, Hiroyuki; Narita, Masato; Yanagida, Atsuko; Tamaki, Nobuyuki; Yagi, Shintaro; Ikai, Iwao; Matsuzaki, Koichi; Uemoto, Shinji

    2009-06-01

    Transforming growth factor beta (TGF-beta) signaling involves both tumor-suppression and oncogenesis. TGF-beta activates the TGF-beta type I receptor (TbetaRI) and c-Jun N-terminal kinase (JNK), which differentially phosphorylate the mediator Smad3 to become COOH-terminally phosphorylated Smad3 (pSmad3C) and linker-phosphorylated Smad3 (pSmad3L). TbetaRI-dependent pSmad3C transmits a tumor-suppressive TGF-beta signal, while JNK-dependent pSmad3L promotes carcinogenesis in human chronic liver disorders. The aim of this study is to elucidate how SP600125, a JNK inhibitor, affected rat hepatocellular carcinoma (HCC) development, while focusing on the domain-specific phosphorylation of Smad3. The rats received subcutaneous injections of either SP600125 or vehicle 11 times weekly together with 100 ppm N-diethylnitrosamine (DEN) administration for 56 days and were sacrificed in order to evaluate HCC development 28 days after the last DEN administration. The number of tumor nodules greater than 3 mm in diameter and the liver weight/body weight ratio were significantly lower in the SP600125-treated rats than those in the vehicle-treated rats (7.9 +/- 0.8 versus 17.7 +/- 0.9: P < 0.001; 6.3 +/- 1.2 versus 7.1 +/- 0.2%: P < 0.05). SP600125 significantly prolonged the median survival time in rats with DEN-induced HCC (113 versus 97 days: log-rank P = 0.0018). JNK/pSmad3L/c-Myc was enhanced in the rat hepatocytes exposed to DEN. However, TbetaRI/pSmad3C/p21(WAF1) was impaired as DEN-induced HCC developed and progressed. The specific inhibition of JNK activity by SP600125 suppressed pSmad3L/c-Myc in the damaged hepatocytes and enhanced pSmad3C/p21(WAF1), acting as a tumor suppressor in normal hepatocytes. Administration of SP600125 to DEN-treated rats shifted hepatocytic Smad3-mediated signal from oncogenesis to tumor suppression, thus suggesting that JNK could be a therapeutic target of human HCC development and progression.

  19. Function-Specific Intracellular Signaling Pathways Downstream of Heparin-Binding EGF-Like Growth Factor Utilized by Human Trophoblasts1

    PubMed Central

    Jessmon, Philip; Kilburn, Brian A.; Romero, Roberto; Leach, Richard E.; Armant, D. Randall

    2010-01-01

    Heparin-binding EGF-like growth factor (HBEGF) is expressed by trophoblast cells throughout gestation. First-trimester cytotrophoblast cells are protected from hypoxia-induced apoptosis because of the accumulation of HBEGF through a posttranscriptional autocrine mechanism. Exogenous application of HBEGF is cytoprotective in a hypoxia/reoxygenation (H/R) injury model and initiates trophoblast extravillous differentiation to an invasive phenotype. The downstream signaling pathways induced by HBEGF that mediate these various cellular activities were identified using two human first-trimester cytotrophoblast cell lines, HTR-8/SVneo and SW.71, with similar results. Recombinant HBEGF (1 nM) induced transient phosphorylation of MAPK3/1 (ERK), MAPK14 (p38), and AKT within 15 min and JNK after 1–2 h. To determine which downstream pathways regulate the various functions of HBEGF, cells were treated with specific inhibitors of the ERK upstream regulator MEK (U0126), the AKT upstream regulator phosphoinositide-3 (PI3)-kinase (LY294002), MAPK14 (SB203580), and JNK (SP600125), as well as with inactive structural analogues. Only SB203580 specifically prevented HBEGF-mediated rescue during H/R, while each inhibitor attenuated HBEGF-stimulated cell migration. Accumulation of HBEGF at reduced oxygen was blocked only by a combination of U0126, SB203580, and SP600125. We conclude that HBEGF advances trophoblast extravillous differentiation through coordinate activation of PI3 kinase, ERK, MAPK14, and JNK, while only MAPK14 is required for its antiapoptotic activity. Additionally, hypoxia induces an autocrine increase in HBEGF protein levels through MAPK14, JNK or ERK. These experiments reveal a complexity of the intracellular signaling circuitry that regulates trophoblast functions critical for implantation and placentation. PMID:20130271

  20. Inhibition of c-Jun N-terminal kinase sensitizes tumor cells to flavonoid-induced apoptosis through down-regulation of JunD

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kook, Sung-Ho; Research Center of Bioactive Materials, Chonbuk National University, Chonju 561-756; Son, Young-Ok

    Reduction of susceptibility to apoptosis signals is a crucial step in carcinogenesis. Therefore, sensitization of tumor cells to apoptosis is a promising therapeutic strategy. c-Jun NH{sub 2}-terminal kinase (JNK) has been implicated in stress-induced apoptosis. However, many studies also emphasize the role of JNK on cell survival, although its mechanisms are not completely understood. Previously, we found that inhibition of JNK activity promotes flavonoid-mediated apoptosis of human osteosarcoma cells. We thus determined whether inhibition of JNK sensitizes tumor cells to a bioflavonoid-induced apoptosis, and whether this effect of JNK is a general effect. As the results, quercetin and genistein asmore » well as a flavonoid fraction induced apoptosis of tumor cells, which was further accelerated by specific JNK inhibitor, SP600125 or by small interfering RNA specific to JNK1/2. This effect was specific to types of cells because it was further apparent in tumorigenic cell lines. Inhibition of JNK by SP600125 also reduced flavonoid-stimulated nuclear induction of JunD which was known to have protective role in apoptosis, whereas JNK inhibition alone had little effect on apoptosis. The flavonoid-induced apoptosis of tumor cells was significantly enhanced by transfecting them with antisense JunD oligonucleotides. These results suggest that inhibition of JNK facilitates flavonoid-induced apoptosis through down-regulation of JunD, which is further sensitive to tumor cells. Therefore, combination with a specific JNK inhibitor further enhances the anti-cancer and chemopreventive potential of bio-flavonoids.« less

  1. The Proteasome Inhibitor Bortezomib Enhances ATRA-Induced Differentiation of Neuroblastoma Cells via the JNK Mitogen-Activated Protein Kinase Pathway

    PubMed Central

    Luo, Peihua; Lin, Meili; Li, Lin; Yang, Bo; He, Qiaojun

    2011-01-01

    Neuroblastoma (NB) is the most common extracranial solid tumor in childhood. Differentiated human NBs are associated with better outcome and lower stage; induction of differentiation is considered to be therapeutically advantageous. All-trans retinoic acid (ATRA) has been shown to induce the differentiation of neuroblastoma (NB) cell lines. The proteasome inhibitor bortezomib inhibits cell growth and angiogenesis in NBs. Here, we investigated the synergistic effect between bortezomib and ATRA in inducing NB cell differentiation in different NB cell lines. Bortezomib combined with ATRA had a significantly enhanced antiproliferative effect. This inhibition was characterized by a synergistic increase in neuronal differentiation. At the same time, the combination therapy showed little neuronal toxicity which was assessed in primary cultures of rat cerebellar granule cells by the MTT assay, PI staining. The combination of bortezomib and ATRA triggered increased differentiation through the activation of proteins, including RARα, RARβ, RARγ, p-JNK and p21, compared with ATRA treatment alone. Using JNK inhibitor SP600125 to block JNK-dependent activity, the combination therapy-induced neuronal differentiation was partially attenuated. In addition, p21 shRNA had no effect on the combination therapy-induced neuronal differentiation. The in vivo antitumor activities were examined in human NB cell xenografts and GFP-labeled human NB cell xenografts. Treatment of human NB cell CHP126-bearing nude mice with ATRA plus bortezomib resulted in more significant tumor growth inhibition than mice treated with either drug alone. These findings provide the rationale for the development of a new therapeutic strategy for NB based on the pharmacological combination of ATRA and bortezomib. PMID:22087283

  2. Rotenone-induced death of RGC-5 cells is caspase independent, involves the JNK and p38 pathways and is attenuated by specific green tea flavonoids.

    PubMed

    Kamalden, T A; Ji, D; Osborne, N N

    2012-05-01

    The aim of the present studies was to characterise cell death following inhibition of mitochondrial complex I with rotenone in a transformed cell line (RGC-5 cells) and to examine the neuroprotective properties of the flavonoids genistein, epigallocatechin gallate (EGCG), epicatechin (EC) and baicalin. Rotenone-induced cell death of RGC-5 cells results in a generation of reactive oxygen species, a breakdown of DNA, the translocation of membrane phosphatidylserine, an up-regulation of haemoxygenase-1 and is unaffected by necrostatin-1 (inhibitor of necroptosis), z-VAD-fmk (pan caspase inhibitor) or NU1025 (PARP inhibitor) but attenuated with SP600125 (JNK inhibitor). Rotenone-induced toxicity of RGC-5 cells also caused an activation of mitogen-activated kinases indicated by an up-regulation and translocation into mitochondria of p-c-Jun, pJNK and pp38. Exposure of RGC-5 cells to rotenone does not affect apoptosis inducing factor or significantly stimulate caspase-3 activity. EGCG and EC both significantly blunt rotenone toxicity of RGC-5 cells at concentrations of 50 μM while genistein and baicalin were without effect. Significantly, genistein is approximately 20 times less efficacious than EGCG (IC(50) 2.5 μM) and EC (IC(50) 1.5 μM) at inhibiting sodium nitroprusside-induced lipid peroxidation. These studies show that rotenone toxicity of RGC-5 cells is neither necroptosis nor caspase-dependent apoptosis but involves the activation of mitogen-activated kinases and is inhibited by a JNK inhibitor, EGCG and EC. Genistein attenuates lipid peroxidation less efficaciously than EC and EGCG and does not affect rotenone toxicity of RGC-5 cells.

  3. [Effects of several inhibitors of intracellular signaling on production of cytokines and signal proteins in RAW 264.7 cells cultivated with low dose ammonium].

    PubMed

    Novoselova, E G; Parfeniuk, S B; Glushkova, O V; Khrenov, M O; Novoselova, T V; Lunin, S M; Fesenko, E E

    2012-01-01

    Effects of four inhibitors of NF-kappaB, SAPK/JNK and TLR4 signaling, namely, inhibitor XII, SP600125, CLI-095 and Oxpapc on a macrophage response to low dose ammonium were studied in RAW 264.7 cells. Low dose ammonium induced pro-inflammatory response in cells as judged from enhanced production of TNF-alpha, IF-gamma, and IL-6, and by activation of signal cascades. The increase in production of cytokines, namely TNF, IFN, and IL-6, demonstrated that low-dose ammonium induced a pro-inflammatory cellular response. In addition, an activation of NF-kappaB and SAPK/JNK cascades, as well as enhancement of TLR4 expression was shown. Each of used inhibitors reduced to a variable degree the pro-inflammatory response of RAW 264.7 cells on chemical toxin by decreasing cytokine production. The inhibitor of NF-kappaB cascade, IKK Inhibitor XII, was more effective, and not only prevented the development of pro-inflammatory response induced by ammonium, but also decreased cytokine production below control values. The inhibitor of extra cellular domains of TLR2 and TLR4 (OxPAPC) had almost the same anti-inflammatory effect, and an addition of the inhibitor of JNK cascade (SP600125) to cell culture practically neutralized effect of ammonium ions by decreasing cytokine production to control level. Inhibitory analysis showed that activation of RAW 264.7 cells induced by chemical toxin coincide incompletely with intracellular signaling pathways that were early determined regarding macrophage's response to toxin from gram-negative bacteria. Nevertheless, application of the inhibitors defended RAW 264.7 from toxic effect of the low dose ammonium.

  4. Mitochondrial JNK activation triggers autophagy and apoptosis and aggravates myocardial injury following ischemia/reperfusion.

    PubMed

    Xu, Jie; Qin, Xinghua; Cai, Xiaoqing; Yang, Lu; Xing, Yuan; Li, Jun; Zhang, Lihua; Tang, Ying; Liu, Jiankang; Zhang, Xing; Gao, Feng

    2015-02-01

    c-Jun N-terminal kinase (JNK) is a stress-activated mitogen-activated protein kinase that plays a central role in initiating apoptosis in disease conditions. Recent studies have shown that mitochondrial JNK signaling is partly responsible for ischemic myocardial dysfunction; however, the underlying mechanism remains unclear. Here we report for the first time that activation of mitochondrial JNK, rather than JNK localization on mitochondria, induces autophagy and apoptosis and aggravates myocardial ischemia/reperfusion injury. Myocardial ischemia/reperfusion induced a dominant increase of mitochondrial JNK phosphorylation, while JNK mitochondrial localization was reduced. Treatment with Tat-SabKIM1, a retro-inverso peptide which blocks JNK interaction with mitochondria, decreased mitochondrial JNK activation without affecting JNK mitochondrial localization following reperfusion. Tat-SabKIM1 treatment reduced Bcl2-regulated autophagy, cytochrome c-mediated apoptosis and myocardial infarct size. Notably, selective inhibition of mitochondrial JNK activation using Tat-SabKIM1 produced a similar infarct size-reducing effect as inhibiting universal JNK activation with JNK inhibitor SP600125. Moreover, insulin-treated animals exhibited significantly dampened mitochondrial JNK activation accompanied by reduced infarct size and diminished autophagy and apoptosis following reperfusion. Taken together, these findings demonstrate that mitochondrial JNK activation, rather than JNK mitochondrial localization, induces autophagy and apoptosis and exacerbates myocardial ischemia/reperfusion injury. Insulin selectively inhibits mitochondrial JNK activation, contributing to insulin cardioprotection against myocardial ischemic/reperfusion injury. This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. The c-Jun N-terminal kinase pathway is critical for cell transformation by the latent membrane protein 1 of Epstein-Barr virus

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kutz, Helmut; Reisbach, Gilbert; Schultheiss, Ute

    The latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) transforms cells activating signal transduction pathways such as NF-{kappa}B, PI3-kinase, or c-Jun N-terminal kinase (JNK). Here, we investigated the functional role of the LMP1-induced JNK pathway in cell transformation. Expression of a novel dominant-negative JNK1 allele caused a block of proliferation in LMP1-transformed Rat1 fibroblasts. The JNK-specific inhibitor SP600125 reproduced this effect in Rat1-LMP1 cells and efficiently interfered with proliferation of EBV-transformed lymphoblastoid cells (LCLs). Inhibition of the LMP1-induced JNK pathway in LCLs caused the downregulation of c-Jun and Cdc2, the essential G2/M cell cycle kinase, which was accompanied bymore » a cell cycle arrest of LCLs at G2/M phase transition. Moreover, SP600125 retarded tumor growth of LCLs in a xenograft model in SCID mice. Our data support a critical role of the LMP1-induced JNK pathway for proliferation of LMP1-transformed cells and characterize JNK as a potential target for intervention against EBV-induced malignancies.« less

  6. Upregulation of RhoB via c-Jun N-terminal kinase signaling induces apoptosis of the human gastric carcinoma NUGC-3 cells treated with NSC12618.

    PubMed

    Kim, Bo-Kyung; Kim, Hwan Mook; Chung, Kyung-Sook; Kim, Dong-Myung; Park, Song-Kyu; Song, Alexander; Won, Kyoung-Jae; Lee, Kiho; Oh, Yu-Kyoung; Lee, Kyeong; Song, Kyung-Bin; Simon, Julian A; Han, Gyoonhee; Won, Misun

    2011-03-01

    RhoB expression is reduced in most invasive tumors, with loss of RhoB expression correlating significantly with tumor stage. Here, we demonstrate that upregulation of RhoB by the potent anticancer agent NSC126188 induces apoptosis of NUGC-3 human gastric carcinoma cells. The crucial role of RhoB in NSC126188-induced apoptosis is indicated by the rescue of NUGC-3 cells from apoptosis by knockdown of RhoB. In the presence of NSC126188, c-Jun N-terminal kinase (JNK) signaling was activated, and the JNK inhibitor SP600125 reduced RhoB expression and suppressed the apoptosis of NUGC-3 cells. Knockdowns of mitogen-activated protein kinase kinase (MKK) 4/7, JNK1/2 and c-Jun downregulated RhoB expression and rescued cells from apoptotic death in the presence of NSC126188. The JNK inhibitor SP600125 suppressed transcriptional activation of RhoB in the presence of NSC126188, as indicated by a reporter assay that used luciferase under the RhoB promoter. The ability of NSC126188 to increase luciferase activity through both the p300-binding site and the inverted CCAAT sequence (iCCAAT box) suggests that JNK signaling to upregulate RhoB expression is mediated through both the p300-binding site and the iCCAAT box. However, the JNK inhibitor SP600125 did not inhibit the upregulation of RhoB by farnesyltransferase inhibitor (FTI)-277. The p300-binding site did not affect activation of the RhoB promoter by FTI-277 in NUGC-3 cells, suggesting that the transcriptional activation of RhoB by NSC126188 occurs by a different mechanism than that reported for FTIs. Our data indicate that NSC126188 increases RhoB expression via JNK-mediated signaling through a p300-binding site and iCCAAT box resulting in apoptosis of NUGC-3 cells.

  7. Molybdenum induces pancreatic β-cell dysfunction and apoptosis via interdependent of JNK and AMPK activation-regulated mitochondria-dependent and ER stress-triggered pathways

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Tsung-Yuan; Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan; Yen, Cheng-Chieh

    2016-03-01

    Molybdenum (Mo), a well-known toxic environmental and industrial pollutant, causes adverse health effects and diseases in humans and has received attention as a potential risk factor for DM. However, the roles of Mo in the mechanisms of the toxicological effects in pancreatic β-cells are mostly unclear. In this study, the results revealed dysfunction of insulin secretion and apoptosis in the pancreatic β-cell-derived RIN-m5F cells and the isolated mouse islets in response to Mo. These effects were accompanied by a mitochondria-dependent apoptotic signals including a decreased in the MMP, an increase in cytochrome c release, and the activation of caspase cascadesmore » and PARP. In addition, ER stress was triggered as indicated by several key molecules of the UPR. Furthermore, exposure to Mo induced the activation of ERK1/2, JNK, AMPKα, and GSK3-α/β. Pretreatment with specific pharmacological inhibitors (in RIN-m5F cells and isolated mouse islets) of JNK (SP600125) and AMPK (Compound C) or transfection with si-RNAs (in RIN-m5F cells) specific to JNK and AMPKα effectively prevented the Mo-induced apoptosis and related signals, but inhibitors of ERK1/2 and GSK3-α/β (PD98059 and LiCl, respectively) did not reverse the Mo-induced effects. Additionally, both the inhibitors and specific si-RNAs could suppress the Mo-induced phosphorylation of JNK and AMPKα each other. Taken together, these results suggest that Mo exerts its cytotoxicity on pancreatic β-cells by inducing dysfunction and apoptosis via interdependent JNK and AMPK activation downstream-regulated mitochondrial-dependent and ER stress-triggered apoptosis pathways. - Highlights: • Molybdenum (Mo) induces pancreatic β-cell dysfunction and apoptosis. • Mo causes β-cell death via mitochondria-dependent caspase cascades signals. • ER stress-triggered apoptotic pathway also regulates Mo-induced β-cell death. • Interdependent of JNK and AMPK activation involves in Mo-induced β-cell apoptosis.« less

  8. Targeting p53 via JNK pathway: a novel role of RITA for apoptotic signaling in multiple myeloma.

    PubMed

    Saha, Manujendra N; Jiang, Hua; Yang, Yijun; Zhu, Xiaoyun; Wang, Xiaoming; Schimmer, Aaron D; Qiu, Lugui; Chang, Hong

    2012-01-01

    The low frequency of p53 alterations e.g., mutations/deletions (∼10%) in multiple myeloma (MM) makes this tumor type an ideal candidate for p53-targeted therapies. RITA is a small molecule which can induce apoptosis in tumor cells by activating the p53 pathway. We previously showed that RITA strongly activates p53 while selectively inhibiting growth of MM cells without inducing genotoxicity, indicating its potential as a drug lead for p53-targeted therapy in MM. However, the molecular mechanisms underlying the pro-apoptotic effect of RITA are largely undefined. Gene expression analysis by microarray identified a significant number of differentially expressed genes associated with stress response including c-Jun N-terminal kinase (JNK) signaling pathway. By Western blot analysis we further confirmed that RITA induced activation of p53 in conjunction with up-regulation of phosphorylated ASK-1, MKK-4 and c-Jun. These results suggest that RITA induced the activation of JNK signaling. Chromatin immunoprecipitation (ChIP) analysis showed that activated c-Jun binds to the activator protein-1 (AP-1) binding site of the p53 promoter region. Disruption of the JNK signal pathway by small interfering RNA (siRNA) against JNK or JNK specific inhibitor, SP-600125 inhibited the activation of p53 and attenuated apoptosis induced by RITA in myeloma cells carrying wild type p53. On the other hand, p53 transcriptional inhibitor, PFT-α or p53 siRNA not only inhibited the activation of p53 transcriptional targets but also blocked the activation of c-Jun suggesting the presence of a positive feedback loop between p53 and JNK. In addition, RITA in combination with dexamethasone, known as a JNK activator, displays synergistic cytotoxic responses in MM cell lines and patient samples. Our study unveils a previously undescribed mechanism of RITA-induced p53-mediated apoptosis through JNK signaling pathway and provides the rationale for combination of p53 activating drugs with JNK

  9. Targeting p53 via JNK Pathway: A Novel Role of RITA for Apoptotic Signaling in Multiple Myeloma

    PubMed Central

    Saha, Manujendra N.; Jiang, Hua; Yang, Yijun; Zhu, Xiaoyun; Wang, Xiaoming; Schimmer, Aaron D.; Qiu, Lugui; Chang, Hong

    2012-01-01

    The low frequency of p53 alterations e.g., mutations/deletions (∼10%) in multiple myeloma (MM) makes this tumor type an ideal candidate for p53-targeted therapies. RITA is a small molecule which can induce apoptosis in tumor cells by activating the p53 pathway. We previously showed that RITA strongly activates p53 while selectively inhibiting growth of MM cells without inducing genotoxicity, indicating its potential as a drug lead for p53-targeted therapy in MM. However, the molecular mechanisms underlying the pro-apoptotic effect of RITA are largely undefined. Gene expression analysis by microarray identified a significant number of differentially expressed genes associated with stress response including c-Jun N-terminal kinase (JNK) signaling pathway. By Western blot analysis we further confirmed that RITA induced activation of p53 in conjunction with up-regulation of phosphorylated ASK-1, MKK-4 and c-Jun. These results suggest that RITA induced the activation of JNK signaling. Chromatin immunoprecipitation (ChIP) analysis showed that activated c-Jun binds to the activator protein-1 (AP-1) binding site of the p53 promoter region. Disruption of the JNK signal pathway by small interfering RNA (siRNA) against JNK or JNK specific inhibitor, SP-600125 inhibited the activation of p53 and attenuated apoptosis induced by RITA in myeloma cells carrying wild type p53. On the other hand, p53 transcriptional inhibitor, PFT-α or p53 siRNA not only inhibited the activation of p53 transcriptional targets but also blocked the activation of c-Jun suggesting the presence of a positive feedback loop between p53 and JNK. In addition, RITA in combination with dexamethasone, known as a JNK activator, displays synergistic cytotoxic responses in MM cell lines and patient samples. Our study unveils a previously undescribed mechanism of RITA-induced p53-mediated apoptosis through JNK signaling pathway and provides the rationale for combination of p53 activating drugs with JNK

  10. Metformin and pioglitazone combination therapy ameliorate polycystic ovary syndrome through AMPK/PI3K/JNK pathway

    PubMed Central

    Wu, Yuanyuan; Li, Pengfen; Zhang, Dan; Sun, Yingpu

    2018-01-01

    Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder, which results in health problems such as menstrual disorders, hyperandrogenism and persistent anovulation. Hyperandrogenism and insulin resistance are the basic characteristics of PCOS. To investigate the combined effect of metformin and pioglitazone on POCS and the potential mechanisms, a rat model of PCOS was established by intramuscular injection of estradiol valerate (EV). The effect of metformin and pioglitazone monotherapy or combination therapy in control rats and PCOS rats was evaluated, involving the testosterone level, follicular development and insulin resistance. The potential mechanism for the therapeutic effect of metformin and pioglitazone on POCS was explored through using three inhibitors of the 5′adenosine monophosphate-activated protein kinase (AMPK)/phosphoinositide-3 kinase (PI3K)/c-Jun N-terminal kinase (JNK) pathway (Compound C, Wortmannin and SP600125). The results showed that EV-induced PCOS rats demonstrated hyperandrogenemia, hyperinsulinemia and follicular dysplasia. Metformin or pioglitazone monotherapy significantly suppressed the high level of testosterone, reduced the raised percentage of cystic follicles and primary follicles, promoted the number of early antral follicles, and markedly decreased the high concentration of fasting insulin and homeostatic model assessment for insulin resistance index in PCOS rats. In addition, metformin and pioglitazone combination therapy demonstrated greater efficacy than its individual components. Furthermore, individual or joint treatment with metformin and pioglitazone affected the phosphorylation level of JNK in PCOS rats. Compound C and Wortmannin eliminated the effect of metformin and pioglitazone combination therapy on improving the follicular growth in PCOS rats, whereas SP600125 treatment enhanced this combination therapy effect. These data suggested that metformin and pioglitazone combination therapy

  11. Antitumor effects of the flavone chalcone: inhibition of invasion and migration through the FAK/JNK signaling pathway in human gastric adenocarcinoma AGS cells.

    PubMed

    Lin, Su-Hsuan; Shih, Yuan-Wei

    2014-06-01

    Chalcones (benzylideneacetophenone) are cancer-preventive food components found in a human diet rich in fruits and vegetables. In this study, we first report the chemopreventive effect of chalcone in human gastric adenocarcinoma cell lines: AGS. The results showed that chalcone could inhibit the abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay, Boyden chamber invasion/migration assay, and wound-healing assay. Molecular data showed that the effect of chalcone in AGS cells might be mediated via sustained inactivation of the phosphorylation of focal adhesion kinase (FAK) and c-Jun N-terminal kinase 1 and 2 (JNK1/2) signal involved in the downregulation of the expressions of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Next, chalcone-treated AGS cells showed tremendous decrease in the phosphorylation and degradation of inhibitor of kappaBα (IκBα), the nuclear level of NF-κB, and the binding ability of NF-κB to NF-κB response element. Furthermore, treating FAK small interfering RNA (FAK siRNA) and specific inhibitor for JNK (SP600125) to AGS cells could reduce the phosphorylation of JNK1/2 and the activity of MMP-2 and MMP-9. Our results revealed that chalcone significantly inhibited the metastatic ability of AGS cells by reducing MMP-2 and MMP-9 expressions concomitantly with a marked reduction on cell invasion and migration through suppressing and JNK signaling pathways. We suggest that chalcone may offer the application in clinical medicine.

  12. Ciclopirox induces autophagy through reactive oxygen species-mediated activation of JNK signaling pathway

    PubMed Central

    Zhou, Hongyu; Shen, Tao; Shang, Chaowei; Luo, Yan; Liu, Lei; Yan, Juming; Li, Yan; Huang, Shile

    2014-01-01

    Ciclopirox olamine (CPX), a fungicide, has been demonstrated as a potential anticancer agent. However, the underlying anticancer mechanism is not well understood. Here, we found that CPX induced autophagy in human rhabdomyosarcoma (Rh30 and RD) cells. It appeared that CPX-induced autophagy was attributed to induction of reactive oxygen species (ROS), as N-acetyl-L-cysteine (NAC), a ROS scavenger and antioxidant, prevented this process. Furthermore, we observed that CPX induced activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 MAPK, which was also blocked by NAC. However, only inhibition of JNK (with SP600125) or expression of dominant negative c-Jun partially prevented CPX-induced autophagy, indicating that ROS-mediated activation of JNK signaling pathway contributed to CPX-induced autophagy. Of interest, inhibition of autophagy by chloroquine (CQ) enhanced CPX-induced cell death, indicating that CPX-induced autophagy plays a pro-survival role in human rhabdomyosarcoma cells. Our finding suggests that the combination with autophagy inhibitors may be a novel strategy in potentiating the anticancer activity of CPX for treatment of rhabdomyosarcoma. PMID:25294812

  13. The Anti-Apoptotic and Cardioprotective Effects of Salvianolic Acid A on Rat Cardiomyocytes following Ischemia/Reperfusion by DUSP-Mediated Regulation of the ERK1/2/JNK Pathway

    PubMed Central

    Chen, Qiuping; Zhu, Shasha; Liu, Yang; Pan, Defeng; Chen, Xiaohu; Li, Dongye

    2014-01-01

    The purpose of this study was to observe the effects of salvianolic acid A (SAA) pretreatment on the myocardium during ischemia/reperfusion (I/R) and to illuminate the interrelationships among dual specificity protein phosphatase (DUSP) 2/4/16, ERK1/2 and JNK pathways during myocardial I/R, with the ultimate goal of elucidating how SAA exerts cardioprotection against I/R injury (IRI). Wistar rats were divided into the following six groups: control group (CON), I/R group, SAA+I/R group, ERK1/2 inhibitor PD098059+I/R group (PD+I/R), PD+SAA+I/R group, and JNK inhibitor SP600125+I/R group (SP+I/R). The cardioprotective effects of SAA on the myocardium during I/R were investigated with a Langendorff device. Heart rate (HR), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), maximum rate of ventricular pressure rise and fall (±dp/dtmax), myocardial infarction areas (MIA), lactate dehydrogenase (LDH), and cardiomyocytes apoptosis were monitored. To determine the crosstalk betwee JNK and ERK1/2 via DUSP2/4/16 with SAA pretreatment, siRNA-DUSP2/4/16 were performed. The expression levels of Bcl-2, Bax, caspase 3, p-JNK, p-ERK1/2 and DUSP2/4/16 in cardiomyocytes were assayed by Western blot. Our results showed that LDH, MIA and cell apoptosis were decreased, and various parameters of heart function were improved by SAA pretreatment and SP application. In the I/R group, the expression levels of p-ERK1/2 and DUSP4/16 were not significantly different compared with the CON group, however, the protein expression levels of p-ERK1/2, Bcl-2 and DUSP4/16 were higher, while p-JNK, Bax, caspase 3 and DUSP2 levels were reduced among the SAA+I/R, PD+SAA+I/R and SP+I/R groups. The above indices were not significantly different between the SAA+I/R and SP+I/R groups. Compared with the SAA+I/R group, p-ERK1/2 was increased and p-JNK was decreased in the SAA+si-DUSP2+I/R, however, p-ERK was downregulated and p-JNK was upregulated in SAA+si-DUSP4+I

  14. Gadd45a, the gene induced by the mood stabilizer valproic acid, regulates neurite outgrowth through JNK and the substrate paxillin in N1E-115 neuroblastoma cells.

    PubMed

    Yamauchi, Junji; Miyamoto, Yuki; Murabe, Mayu; Fujiwara, Yoko; Sanbe, Atsushi; Fujita, Yuko; Murase, Shoko; Tanoue, Akito

    2007-05-15

    Valproic acid (VPA), a mood stabilizer and anticonvulsant, has a variety of neurotrophic functions; however, less is known about how VPA regulates neurite outgrowth. Here, using N1E-115 neuroblastoma cells as the model, we show that VPA upregulates Gadd45a to trigger activation of the downstream JNK cascade controlling neurite outgrowth. VPA induces the phosphorylation of c-Jun N-terminal kinase (JNK) and the substrate paxillin, while VPA induction of neurite outgrowth is inhibited by JNK inhibitors (SP600125 and the small JNK-binding peptide) or a paxillin construct harboring a Ser 178-to-Ala mutation at the JNK phosphorylation. Transfection of Gadd45a, acting through the effector MEKK4, leads to the phosphorylation of the JNK cascade. Conversely, knockdown of Gadd45a with siRNA reduces the effect of VPA. Taken together, these results suggest that upregulation of Gadd45a explains one of the mechanisms whereby VPA induces the neurotrophic effect, providing a new role of Gadd45a in neurite outgrowth.

  15. Resveratrol Inhibits the Epidermal Growth Factor-Induced Migration of Osteoblasts: the Suppression of SAPK/JNK and Akt.

    PubMed

    Kawabata, Tetsu; Tokuda, Haruhiko; Fujita, Kazuhiko; Kainuma, Shingo; Sakai, Go; Matsushima-Nishiwaki, Rie; Kozawa, Osamu; Otsuka, Takanobu

    2017-01-01

    Resveratrol is a polyphenol enriched in the skins of grapes and berries, that shows various beneficial effects for human health. In the present study, we investigated the mechanism behind the epidermal growth factor (EGF)-induced migration of osteoblast-like MC3T3-E1 cells, and the effect of resveratrol on this cell migration. The cell migration was examined using Boyden chamber, and phosphorylation of each kinase was analyzed by Western blotting. The EGF-induced migration was suppressed by PD98059, an inhibitor of MEK1/2, as well as SB203580, an inhibitor of p38 MAP kinase, SP600125, an inhibitor of SAPK/JNK, and deguelin, an inhibitor of Akt. In contrast, rapamycin, an inhibitor of upstream kinase of p70 S6 kinase, and fasudil, an inhibitor of Rho-kinase, hardly affected the migration. Resveratrol significantly reduced the EGF-induced migration in a dose-dependent manner. SRT1720, an SIRT1 activator, suppressed the migration by EGF. In addition, resveratrol markedly attenuated the EGF-induced phosphorylation of SAPK/JNK and Akt without affecting the phosphorylation of p44/p42 MAP kinase or p38 MAP kinase. The phosphorylation of SAPK/JNK and Akt induced by EGF was down-regulated by SRT1720. Our results strongly suggest that resveratrol reduces the EGF-stimulated migration of osteoblasts via suppression of SAPK and Akt, and that the inhibitory effect of resveratrol is mediated in part via SIRT1. © 2017 The Author(s). Published by S. Karger AG, Basel.

  16. 3-MCPD 1-Palmitate Induced Tubular Cell Apoptosis In Vivo via JNK/p53 Pathways

    PubMed Central

    Liu, Man; Huang, Guoren; Wang, Thomas T.Y.; Sun, Xiangjun; Yu, Liangli (Lucy)

    2016-01-01

    Fatty acid esters of 3-chloro-1, 2-propanediol (3-MCPD esters) are a group of processing induced food contaminants with nephrotoxicity but the molecular mechanism(s) remains unclear. This study investigated whether and how the JNK/p53 pathway may play a role in the nephrotoxic effect of 3-MCPD esters using 3-MCPD 1-palmitate (MPE) as a probe compound in Sprague Dawley rats. Microarray analysis of the kidney from the Sprague Dawley rats treated with MPE, using Gene Ontology categories and KEGG pathways, revealed that MPE altered mRNA expressions of the genes involved in the mitogen-activated protein kinase (JNK and ERK), p53, and apoptotic signal transduction pathways. The changes in the mRNA expressions were confirmed by qRT-PCR and Western blot analyses and were consistent with the induction of tubular cell apoptosis as determined by histopathological, TUNEL, and immunohistochemistry analyses in the kidneys of the Sprague Dawley rats. Additionally, p53 knockout attenuated the apoptosis, and the apoptosis-related protein bax expression and cleaved caspase-3 activation induced by MPE in the p53 knockout C57BL/6 mice, whereas JNK inhibitor SP600125 but not ERK inhibitor U0126 inhibited MPE-induced apoptosis, supporting the conclusion that JNK/p53 might play a critical role in the tubular cell apoptosis induced by MPE and other 3-MCPD fatty acid esters. PMID:27008853

  17. Blockage of JNK pathway enhances arsenic trioxide-induced apoptosis in human keratinocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huang, H.-S., E-mail: huanghs@mail.ncku.edu.t; Liu, Z.-M.; Hong, D.-Y.

    2010-04-15

    Arsenic is well known as a carcinogen predisposing humans to some severe diseases and also as an effective medicine for treating acute promyelocytic leukemia, syphilis, and psoriasis. Multiple active mechanisms, including cell cycle arrest and apoptosis, have been proposed in therapy; however, the opposing effects of arsenic remain controversial. Our previous study found that arsenic trioxide (ATO)-induced activation of p21{sup WAF1/CIP1} (p21) led to A431 cell death through the antagonistic effects of the signaling of ERK1/2 and JNK1. In the current study, the inhibitory effects of JNK1 on ATO-induced p21 expression were explored. Over-expression of JNK1 in A431 cells couldmore » inhibit p21 expression, which was associated with HDAC1 and TGIF. Using the GST pull-down assay and fluorescence resonance energy transfer analysis, N-terminal domain (amino acids 1-108) of TGIF, critical to its binding with c-Jun, was found. Using reporter assays, requirement of the C-terminal domain (amino acids 138-272) of TGIF to suppress ATO-induced p21 expression was observed. Thus, the domains of TGIF that carried out its inhibitory effects on p21 were identified. Finally, treatment with JNK inhibitor SP600125 could enhance ATO-induced apoptosis of HaCaT keratinocytes by using flow cytometry.« less

  18. Iodine-131 treatment of thyroid cancer cells leads to suppression of cell proliferation followed by induction of cell apoptosis and cell cycle arrest by regulation of B-cell translocation gene 2-mediated JNK/NF-κB pathways.

    PubMed

    Zhao, L M; Pang, A X

    2017-01-16

    Iodine-131 (131I) is widely used for the treatment of thyroid-related diseases. This study aimed to investigate the expression of p53 and BTG2 genes following 131I therapy in thyroid cancer cell line SW579 and the possible underlying mechanism. SW579 human thyroid squamous carcinoma cells were cultured and treated with 131I. They were then assessed for 131I uptake, cell viability, apoptosis, cell cycle arrest, p53 expression, and BTG2 gene expression. SW579 cells were transfected with BTG2 siRNA, p53 siRNA and siNC and were then examined for the same aforementioned parameters. When treated with a JNK inhibitor of SP600125 and 131I or with a NF-κB inhibitor of BMS-345541 and 131I, non-transfected SW579 cells were assessed in JNK/NFκB pathways. It was observed that 131I significantly inhibited cell proliferation, promoted cell apoptosis and cell cycle arrest. Both BTG2 and p53 expression were enhanced in a dose-dependent manner. An increase in cell viability by up-regulation in Bcl2 gene, a decrease in apoptosis by enhanced CDK2 gene expression and a decrease in cell cycle arrest at G0/G1 phase were also observed in SW579 cell lines transfected with silenced BTG2 gene. When treated with SP600125 and 131I, the non-transfected SW579 cell lines significantly inhibited JNK pathway, NF-κB pathway and the expression of BTG2. However, when treated with BMS-345541 and 131I, only the NF-κB pathway was suppressed. 131I suppressed cell proliferation, induced cell apoptosis, and promoted cell cycle arrest of thyroid cancer cells by up-regulating B-cell translocation gene 2-mediated activation of JNK/NF-κB pathways.

  19. JNK Activation Contributes to Oxidative Stress-Induced Parthanatos in Glioma Cells via Increase of Intracellular ROS Production.

    PubMed

    Zheng, Linjie; Wang, Chen; Luo, Tianfei; Lu, Bin; Ma, Hongxi; Zhou, Zijian; Zhu, Dong; Chi, Guangfan; Ge, Pengfei; Luo, Yinan

    2017-07-01

    Parthanatos is a form of PARP-1-dependent programmed cell death. The induction of parthanatos is emerging as a new strategy to kill gliomas which are the most common type of primary malignant brain tumor. Oxidative stress is thought to be a critical factor triggering parthanatos, but its underlying mechanism is poorly understood. In this study, we used glioma cell lines and H 2 O 2 to investigate the role of JNK in glioma cell parthanatos induced by oxidative stress. We found that exposure to H 2 O 2 not only induced intracellular accumulation of ROS but also resulted in glioma cell death in a concentration- and incubation time-dependent manner, which was accompanied with cytoplasmic formation of PAR polymer, expressional upregulation of PARP-1, mitochondrial depolarization, and AIF translocation to nucleus. Pharmacological inhibition of PARP-1 with 3AB or genetic knockdown of its level with siRNA rescued glioma cell death, as well as suppressed cytoplasmic accumulation of PAR polymer and nuclear translocation of AIF, which were consistent with the definition of parthanatos. Moreover, the phosphorylated level of JNK increased markedly with the extension of H 2 O 2 exposure time. Either attenuation of intracellular ROS with antioxidant NAC or inhibition of JNK phosphorylation with SP600125 or JNK siRNA could significantly prevent H 2 O 2 -induced parthanatos in glioma cells. Additionally, inhibition of JNK with SP600125 alleviated intracellular accumulation of ROS and attenuated mitochondrial generation of superoxide. Thus, we demonstrated that JNK activation contributes to glioma cell parthanatos caused by oxidative stress via increase of intracellular ROS generation.

  20. Dihydroartemisinin induces endothelial cell anoikis through the activation of the JNK signaling pathway

    PubMed Central

    Zhang, Jiao; Guo, Ling; Zhou, Xia; Dong, Fengyun; Li, Liqun; Cheng, Zuowang; Xu, Yinghua; Liang, Jiyong; Xie, Qi; Liu, Ju

    2016-01-01

    Angiogenesis is required for the growth and metastasis of solid tumors. The anti-malarial agent dihydroartemisinin (DHA) demonstrates potent anti-angiogenic activity, but the underlying molecular mechanisms are not yet fully understood. During the process of angiogenesis, endothelial cells migrating from existing capillaries may undergo programmed cell death after detaching from the extracellular matrix, a process that is defined as anchorage-dependent apoptosis or anoikis. In the present study, DHA-induced cell death was compared in human umbilical vein endothelial cells (HUVECs) cultured in suspension and attached to culture plates. In suspended HUVECs, the cell viability was decreased and apoptosis was increased with the treatment of 50 µM DHA for 5 h, while the same treatment did not affect the attached HUVECs. In addition, 50 µM DHA increased the phosphorylation of c-Jun N-terminal kinase (JNK) in suspended HUVECs, but not in attached HUVECs, for up to 5 h of treatment. The JNK inhibitor, SP600125, reversed DHA-induced cell death in suspended HUVECs, suggesting that the JNK pathway may mediate DHA-induced endothelial cell anoikis. The data from the present study indicates a novel mechanism for understanding the anti-angiogenic effects of DHA, which may be used as a component for chemotherapy. PMID:27602117

  1. Vitamin K2 Induces Mitochondria-Related Apoptosis in Human Bladder Cancer Cells via ROS and JNK/p38 MAPK Signal Pathways

    PubMed Central

    Duan, Fengsen; Yu, Yuejin; Guan, Rijian; Xu, Zhiliang; Liang, Huageng; Hong, Ling

    2016-01-01

    The effects of vitamin K2 on apoptosis in a variety of cancer cells have been well established in previous studies. However, the apoptotic effect of vitamin K2 on bladder cancer cells has not been evaluated. The aim of this study is to examine the apoptotic activity of Vitamin K2 in bladder cancer cells and investigate the underlying mechanism. In this study, Vitamin K2 induced apoptosis in bladder cancer cells through mitochondria pathway including loss of mitochondria membrane potential, cytochrome C release and caspase-3 cascade. Furthermore, the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK was detected in Vitamin K2-treated cells and both SP600125 (an inhibitor of JNK) and SB203580 (an inhibitor of p38 MAPK) completely abolished the Vitamin K2-induced apoptosis and loss of mitochondria membrane potential. Moreover, the generation of reactive oxygen species (ROS) was detected in bladder cancer cells, upon treatment of vitamin K2 and the anti-oxidant N-acetyl cysteine (NAC) almost blocked the Vitamin K2-triggered apoptosis, loss of mitochondria membrane potential and activation of JNK and p38 MAPK. Taken together, these findings revealed that Vitamin K2 induces apoptosis in bladder cancer cells via ROS-mediated JNK/p38 MAPK and Mitochondrial pathways. PMID:27570977

  2. Vitamin K2 Induces Mitochondria-Related Apoptosis in Human Bladder Cancer Cells via ROS and JNK/p38 MAPK Signal Pathways.

    PubMed

    Duan, Fengsen; Yu, Yuejin; Guan, Rijian; Xu, Zhiliang; Liang, Huageng; Hong, Ling

    2016-01-01

    The effects of vitamin K2 on apoptosis in a variety of cancer cells have been well established in previous studies. However, the apoptotic effect of vitamin K2 on bladder cancer cells has not been evaluated. The aim of this study is to examine the apoptotic activity of Vitamin K2 in bladder cancer cells and investigate the underlying mechanism. In this study, Vitamin K2 induced apoptosis in bladder cancer cells through mitochondria pathway including loss of mitochondria membrane potential, cytochrome C release and caspase-3 cascade. Furthermore, the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK was detected in Vitamin K2-treated cells and both SP600125 (an inhibitor of JNK) and SB203580 (an inhibitor of p38 MAPK) completely abolished the Vitamin K2-induced apoptosis and loss of mitochondria membrane potential. Moreover, the generation of reactive oxygen species (ROS) was detected in bladder cancer cells, upon treatment of vitamin K2 and the anti-oxidant N-acetyl cysteine (NAC) almost blocked the Vitamin K2-triggered apoptosis, loss of mitochondria membrane potential and activation of JNK and p38 MAPK. Taken together, these findings revealed that Vitamin K2 induces apoptosis in bladder cancer cells via ROS-mediated JNK/p38 MAPK and Mitochondrial pathways.

  3. Increased level of apoptosis in rat brains and SH-SY5Y cells exposed to excessive fluoride--a mechanism connected with activating JNK phosphorylation.

    PubMed

    Liu, Yan-Jie; Guan, Zhi-Zhong; Gao, Qin; Pei, Jin-Jing

    2011-07-28

    In order to reveal the mechanism of the brain injury induced by chronic fluorosis, the levels of apoptosis and c-Jun N-terminal kinases (JNK) in brains of rats and SH-SY5Y cells exposed to different concentrations of sodium fluoride (NaF) were detected. The dental fluorosis and fluoride contents in blood, urine and bones of rats were measured to evaluate the exhibition of fluorosis. The apoptotic death rate was measured by flow cytometry and the expression of JNK at protein level by Western blotting. The results showed that as compared with controls, the apoptotic death rate was obviously increased in brains of the rats exposed to high-fluoride (50ppm) for 6 months with a concentration dependent manner, but no significant change for 3 months. In SH-SY5Y cells treated with high concentration (50ppm) of fluoride, the increased apoptotic death rate was obviously observed as compared to controls. In addition, the expressions of phospho-JNK at protein level were raised by 20.5% and 107.6%, respectively, in brains of the rats exposed to low-fluoride (5ppm) and high-fluoride for 6 months; while no significant changes were found between the rats exposed to fluoride and the controls for 3 months. The protein level of phospho-JNK was also increased in SH-SY5Y cells exposed to high-fluoride. There were no changes of total-JNK both in the rats and in the SH-SY5Y cells exposed to excessive fluoride as compared to controls. When SH-SY5Y cells were singly treated with SP600125, an inhibitor of phospho-JNK, the decreased expression of phospho-JNK, but no apoptosis, was detected. Interestingly, after JNK phosphorylation in the cultured cells was inhibited by SP600125, the treatment with high-fluoride did not induce the increase of apoptosis. In addition, there was a positive correlation between the expression of phospho-JNK and the apoptotic death rate in rat brains or SH-SY5Y cells treated with high-fluoride. The results indicated that exposure to excessive fluoride resulted in

  4. TGF-beta and HGF transmit the signals through JNK-dependent Smad2/3 phosphorylation at the linker regions.

    PubMed

    Mori, Shigeo; Matsuzaki, Koichi; Yoshida, Katsunori; Furukawa, Fukiko; Tahashi, Yoshiya; Yamagata, Hideo; Sekimoto, Go; Seki, Toshihito; Matsui, Hirofumi; Nishizawa, Mikio; Fujisawa, Jun-ichi; Okazaki, Kazuichi

    2004-09-23

    Although hepatocyte growth factor (HGF) can act synergistically or antagonistically with transforming growth factor-beta (TGF-beta) signaling, molecular mechanism of their crosstalk remains unknown. Using antibodies which selectively distinguished receptor-regulated Smads (R-Smads) phosphorylated at linker regions from those at C-terminal regions, we herein showed that either HGF or TGF-beta treatment of normal stomach-origin cells activated the JNK pathway, thereafter inducing endogenous R-Smads phosphorylation at linker regions. However, the phosphorylation at their C-terminal regions was not induced by HGF treatment. The activated JNK could directly phosphorylate R-Smads in vitro at the same sites that were phosphorylated in response to TGF-beta or HGF in vivo. Thus, the linker regions of R-Smads were the common phosphorylation sites for HGF and TGF-beta signaling pathways. The phosphorylation induced by simultaneous treatment with HGF and TGF-beta allowed R-Smads to associate with Smad4 and to translocate into the nucleus. JNK pathway involved HGF and TGF-beta-mediated infiltration potency since a JNK inhibitor SP600125 caused the reduction of invasive capacity induced by HGF and TGF-beta signals. Moreover, a combined treatment with HGF and TGF-beta led to a potent increase in plasminogen activator inhibitor type 1 transcriptional activity through Smad3 phosphorylation at the linker region. In contrast, HGF treatment reduced TGF-beta-dependent activation of p15INK4B promoter, in which Smad3 phosphorylation at the C-terminal region was involved. In conclusion, HGF and TGF-beta transmit the signals through JNK-mediated R-Smads phosphorylation at linker regions.

  5. Endophilin-1 regulates blood-brain barrier permeability via EGFR-JNK signaling pathway.

    PubMed

    Chen, Lin; Liu, Wenjing; Wang, Ping; Xue, Yixue; Su, Qingjie; Zeng, Chaosheng; Shang, Xiuli

    2015-05-05

    Endophilin-1 (Endo1), a multifunctional protein, is essential for synaptic vesicle endocytosis. However, the role and mechanism of endophilin-1 in blood-brain barrier (BBB) function are still unclear. This study was performed to determine whether endophilin-1 regulated BBB permeability via the EGFR-JNK signaling pathway. In the present study, we found that endophilin-1 over-expression in human cerebral microvascular endothelial cell (hCMEC/D3) increased BBB permeability and meanwhile reduced the expression levels of epidermal growth factor receptor (EGFR), phosphorylated c-Jun N-terminal kinase (p-JNK). While endophilin-1 knockdown led to the contrary results. After JNK inhibitor SP600125 was administered to the endophilin-1 silenced hCMEC/D3 cells, the transendothelial electrical resistance (TEER) value was decreased and the permeability coefficient values to 4kDa and 40kDa FITC-dextran were increased. Results observed by Transmission electron microscopy (TEM) showed that tight junctions (TJs) were opened. Moreover, immunofluorescence and Western blot assays revealed the discontinuous distribution of TJ-associated proteins ZO-1, occludin on cell-cell boundaries and a significant decrease in protein expressing levels. Therefore, these results indicated that endophilin-1 positively regulated BBB permeability via the EGFR-JNK signaling pathway in hCMEC/D3 cells, which would provide an experimental basis for further research on endophilin-1 mediated the opening of BBB. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Proteasome inhibitor MG132 induces selective apoptosis in glioblastoma cells through inhibition of PI3K/Akt and NFkappaB pathways, mitochondrial dysfunction, and activation of p38-JNK1/2 signaling.

    PubMed

    Zanotto-Filho, Alfeu; Braganhol, Elizandra; Battastini, Ana Maria Oliveira; Moreira, José Cláudio Fonseca

    2012-12-01

    Proteasome inhibitors are emerging as a new class of anticancer agents. In this work, we examined the mechanisms underlying cytotoxicity, selectivity and adjuvant potential of the proteasome inhibitor MG132 in a panel of glioblastoma (GBM) cells (U138MG, C6, U87 and U373) and in normal astrocytes. MG132 markedly inhibited GBM cells growth irrespective of the p53 or PTEN mutational status of the cells whereas astrocytic viability was not affected, suggesting a selective toxicity of MG132 to cancerous glial cells. Mechanistically, MG132 arrested cells in G2/M phase of the cell cycle and increased p21(WAF1) protein immunocontent. Following cell arrest, cells become apoptotic as shown by annexin-V binding, caspase-3 activation, chromatin condensation and formation of sub-G1 apoptotic cells. MG132 promoted mitochondrial depolarization and decreased the mitochondrial antiapoptotic protein bcl-xL; it also induced activation of JNK and p38, and inhibition of NFkappaB and PI3K/Akt survival pathways. Pre-treatment of GBMs with the mitochondrial permeability transition pore inhibitor, bongkrekic acid, or pharmacological inhibitors of JNK1/2 and p38, SP600125 and SB203580, attenuated MG132-induced cell death. Besides its apoptotic effect alone, MG132 also enhanced the antiglioma effect of the chemotherapeutics cisplatin, taxol and doxorubicin in C6 and U138MG cells, indicating an adjuvant/chemosensitizer potential. In summary, MG132 exerted profound and selective toxicity in GBMs, being a potential agent for further testing in animal models of the disease.

  7. UVC-induced apoptosis in Dubca cells is independent of JNK activation and p53{sup Ser-15} phosphorylation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chathoth, Shahanas; Thayyullathil, Faisal; Hago, Abdulkader

    2009-06-12

    Ultraviolet C (UVC) irradiation in mammalian cell lines activates a complex signaling network that leads to apoptosis. By using Dubca cells as a model system, we report the presence of a UVC-induced apoptotic pathway that is independent of c-Jun N-terminal kinases (JNKs) activation and p53 phosphorylation at Ser{sup 15}. Irradiation of Dubca cells with UVC results in a rapid JNK activation and phosphorylation of its downstream target c-Jun, as well as, phosphorylation of activating transcription factor 2 (ATF2). Pre-treatment with JNK inhibitor, SP600125, inhibited UVC-induced c-Jun phosphorylation without preventing UVC-induced apoptosis. Similarly, inhibition of UVC-induced p53 phosphorylation did not preventmore » Dubca cell apoptosis, suggesting that p53{sup Ser-15} phosphorylation is not associated with UVC-induced apoptosis signaling. The pan-caspase inhibitor z-VAD-fmk inhibited UVC-induced PARP cleavage, DNA fragmentation, and ultimately apoptosis of Dubca cells. Altogether, our study clearly indicates that UVC-induced apoptosis is independent of JNK and p53 activation in Dubca cells, rather, it is mediated through a caspase dependent pathway. Our findings are not in line with the ascribed critical role for JNKs activation, and downstream phosphorylation of targets such as c-Jun and ATF2 in UVC-induced apoptosis.« less

  8. Hit-to-lead optimization and kinase selectivity of imidazo[1,2-a]quinoxalin-4-amine derived JNK1 inhibitors.

    PubMed

    Li, Bei; Cociorva, Oana M; Nomanbhoy, Tyzoon; Weissig, Helge; Li, Qiang; Nakamura, Kai; Liyanage, Marek; Zhang, Melissa C; Shih, Ann Y; Aban, Arwin; Hu, Yi; Cajica, Julia; Pham, Lan; Kozarich, John W; Shreder, Kevin R

    2013-09-15

    As the result of a rhJNK1 HTS, the imidazo[1,2-a]quinoxaline 1 was identified as a 1.6 μM rhJNK1 inhibitor. Optimization of this compound lead to AX13587 (rhJNK1 IC50=160 nM) which was co-crystallized with JNK1 to identify key molecular interactions. Kinase profiling against 125+ kinases revealed AX13587 was an inhibitor of JNK, MAST3, and MAST4 whereas its methylene homolog AX14373 (native JNK1 IC50=47 nM) was a highly specific JNK inhibitor. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Acute ethanol exposure-induced autophagy-mediated cardiac injury via activation of the ROS-JNK-Bcl-2 pathway.

    PubMed

    Zhu, Zhongxin; Huang, Yewei; Lv, Lingchun; Tao, Youli; Shao, Minglong; Zhao, Congcong; Xue, Mei; Sun, Jia; Niu, Chao; Wang, Yang; Kim, Sunam; Cong, Weitao; Mao, Wei; Jin, Litai

    2018-02-01

    Binge drinking is associated with increased cardiac autophagy, and often triggers heart injury. Given the essential role of autophagy in various cardiac diseases, this study was designed to investigate the role of autophagy in ethanol-induced cardiac injury and the underlying mechanism. Our study showed that ethanol exposure enhanced the levels of LC3-II and LC3-II positive puncta and promoted cardiomyocyte apoptosis in vivo and in vitro. In addition, we found that ethanol induced autophagy and cardiac injury largely via the sequential triggering of reactive oxygen species (ROS) accumulation, activation of c-Jun NH2-terminal kinase (JNK), phosphorylation of Bcl-2, and dissociation of the Beclin 1/Bcl-2 complex. By contrast, inhibition of ethanol-induced autophagic flux with pharmacologic agents in the hearts of mice and cultured cells significantly alleviated ethanol-induced cardiomyocyte apoptosis and heart injury. Elimination of ROS with the antioxidant N-acetyl cysteine (NAC) or inhibition of JNK with the JNK inhibitor SP600125 reduced ethanol-induced autophagy and subsequent autophagy-mediated apoptosis. Moreover, metallothionein (MT), which can scavenge reactive oxygen and nitrogen species, also attenuated ethanol-induced autophagy and cell apoptosis in MT-TG mice. In conclusion, our findings suggest that acute ethanol exposure induced autophagy-mediated heart toxicity and injury mainly through the ROS-JNK-Bcl-2 signaling pathway. © 2017 Wiley Periodicals, Inc.

  10. Leflunomide or A77 1726 protect from acetaminophen-induced cell injury through inhibition of JNK-mediated mitochondrial permeability transition in immortalized human hepatocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Latchoumycandane, Calivarathan; Seah, Quee Ming; Tan, Rachel C.H.

    2006-11-15

    Leflunomide, a disease-modifying anti-rheumatic drug, protects against T-cell-mediated liver injury by poorly understood mechanisms. The active metabolite of leflunomide, A77 1726 (teriflunomide) has been shown to inhibit stress-activated protein kinases (JNK pathway), which are key regulators of mitochondria-mediated cell death. Therefore, we hypothesized that leflunomide may protect from drugs that induce the mitochondrial permeability transition (mPT) by blocking the JNK signaling pathway. To this end, we exposed cultured immortalized human hepatocytes (HC-04) to the standard protoxicant drug acetaminophen (APAP), which induces CsA-sensitive mPT-mediated cell death. We determined the effects of leflunomide on the extent of APAP-induced hepatocyte injury and themore » upstream JNK-mediated mitochondrial signaling pathways. We found that leflunomide or A77 1726 concentration-dependently protected hepatocytes from APAP (1 mM)-induced mitochondrial permeabilization and lethal cell injury. This was not due to proximal inhibition of CYP-catalyzed APAP bioactivation to its thiol-reactive metabolite. Instead, we demonstrate that leflunomide (20 {mu}M) inhibited the APAP-induced early (3 h) activation (phosphorylation) of JNK1/2, thus inhibiting phosphorylation of the anti-apoptotic protein Bcl-2 and preventing P-Bcl-2-mediated induction of the mPT. This greatly attenuated mitochondrial cytochrome c release, which we used as a marker for mitochondrial permeabilization. The specific JNK2 inhibitor SP600125 similarly protected from APAP-induced cell death. In conclusion, these findings are consistent with our hypothesis that leflunomide protects from protoxicant-induced hepatocyte injury by inhibiting JNK signaling and preventing mPT induction.« less

  11. Involvement of p38 MAPK- and JNK-modulated expression of Bcl-2 and Bax in Naja nigricollis CMS-9-induced apoptosis of human leukemia K562 cells.

    PubMed

    Chen, Ying-Jung; Liu, Wen-Hsin; Kao, Pei-Hsiu; Wang, Jeh-Jeng; Chang, Long-Sen

    2010-06-15

    CMS-9, a phospholipase A(2) (PLA(2)) isolated from Naja nigricollis venom, induced apoptosis of human leukemia K562 cells, characterized by mitochondrial depolarization, modulation of Bcl-2 family members, cytochrome c release and activation of caspases 9 and 3. Moreover, an increase in intracellular Ca2+ concentration and the production of reactive oxygen species (ROS) was noted. Pretreatment with BAPTA-AM (Ca2+ chelator) and N-acetylcysteine (NAC, ROS scavenger) proved that Ca2+ was an upstream event in inducing ROS generation. Upon exposure to CMS-9, activation of p38 MAPK and JNK was observed in K562 cells. BAPTA-AM or NAC abrogated CMS-9-elicited p38 MAPK and JNK activation, and rescued viability of CMS-9-treated K562 cells. SB202190 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor) suppressed CMS-9-induced dissipation of mitochondrial membrane potential, Bcl-2 down-regulation, Bax up-regulation and increased mitochondrial translocation of Bax. Inactivation of PLA(2) activity reduced drastically the cytotoxicity of CMS-9, and a combination of lysophosphatidylcholine and stearic acid mimicked the cytotoxic effects of CMS-9. Taken together, our data suggest that CMS-9-induced apoptosis of K562 cells is catalytic activity-dependent and is mediated through mitochondria-mediated death pathway triggered by Ca2+/ROS-evoked p38 MAPK and JNK activation. 2010 Elsevier Ltd. All rights reserved.

  12. Tolerance to the antinociceptive effects of chronic morphine requires c-Jun N-terminal kinase.

    PubMed

    Marcus, David J; Zee, Michael; Hughes, Alex; Yuill, Matthew B; Hohmann, Andrea G; Mackie, Ken; Guindon, Josée; Morgan, Daniel J

    2015-06-12

    Morphine and fentanyl are opioid analgesics in wide clinical use that act through the μ-opioid receptor (MOR). However, one limitation of their long-term effectiveness is the development of tolerance. Receptor desensitization has been proposed as a putative mechanism driving tolerance to G protein-coupled receptor (GPCR) agonists. Recent studies have found that tolerance to morphine is mediated by the c-Jun N-terminal Kinase (JNK) signaling pathway. The goal of the present study was to test the hypotheses that: 1) JNK inhibition will be antinociceptive on its own; 2) JNK inhibition will augment morphine antinociception and; 3) JNK mediates chronic tolerance for the antinociceptive effects of morphine using acute (hotplate and tail-flick), inflammatory (10 μl of formalin 2.5%) and chemotherapy (cisplatin 5 mg/kg ip once weekly)-induced neuropathic pain assays. We found that JNK inhibition by SP600125 (3 mg/kg) produces a greater antinociceptive effect than morphine (6 mg/kg) alone in the formalin test. Moreover, co-administration of morphine (6 mg/kg) with SP600125 (3 mg/kg) produced a sub-additive antinociceptive effect in the formalin test. We also show that pre-treatment with SP600125 (3 or 10 mg/kg), attenuates tolerance to the antinociceptive effects of morphine (10 mg/kg), but not fentanyl (0.3 mg/kg), in the tail-flick and hotplate tests. Pre-treatment with SP600125 also attenuates tolerance to the hypothermic effects of both morphine and fentanyl. We also examined the role of JNK in morphine tolerance in a cisplatin-induced model of neuropathic pain. Interestingly, treatment with SP600125 (3 mg/kg) alone attenuated mechanical and cold allodynia in a chemotherapy-induced pain model using cisplatin. Strikingly, SP600125 (3 mg/kg) pre-treatment prolonged the anti-allodynic effect of morphine by several days (5 and 7 days for mechanical and cold, respectively). These results demonstrate that JNK signaling plays a crucial role in mediating antinociception as

  13. High-Dose Fluoride Impairs the Properties of Human Embryonic Stem Cells via JNK Signaling.

    PubMed

    Fu, Xin; Xie, Fang-Nan; Dong, Ping; Li, Qiu-Chen; Yu, Guang-Yan; Xiao, Ran

    2016-01-01

    Fluoride is a ubiquitous natural substance that is often used in dental products to prevent dental caries. The biphasic actions of fluoride imply that excessive systemic exposure to fluoride can cause harmful effects on embryonic development in both animal models and humans. However, insufficient information is available on the effects of fluoride on human embryonic stem cells (hESCs), which is a novel in vitro humanized model for analyzing the embryotoxicities of chemical compounds. Therefore, we investigated the effects of sodium fluoride (NaF) on the proliferation, differentiation and viability of H9 hESCs. For the first time, we showed that 1 mM NaF did not significantly affect the proliferation of hESCs but did disturb the gene expression patterns of hESCs during embryoid body (EB) differentiation. Higher doses of NaF (2 mM and above) markedly decreased the viability and proliferation of hESCs. The mode and underlying mechanism of high-dose NaF-induced cell death were further investigated by assessing the sub-cellular morphology, mitochondrial membrane potential (MMP), caspase activities, cellular reactive oxygen species (ROS) levels and activation of mitogen-activated protein kinases (MAPKs). High-dose NaF caused the death of hESCs via apoptosis in a caspase-mediated but ROS-independent pathway, coupled with an increase in the phospho-c-Jun N-terminal kinase (p-JNK) levels. Pretreatment with a p-JNK-specific inhibitor (SP600125) could effectively protect hESCs from NaF-induced cell death in a concentration- and time-dependent manner. These findings suggest that NaF might interfere with early human embryogenesis by disturbing the specification of the three germ layers as well as osteogenic lineage commitment and that high-dose NaF could cause apoptosis through a JNK-dependent pathway in hESCs.

  14. JNK-induced MCP-1 production in spinal cord astrocytes contributes to central sensitization and neuropathic pain

    PubMed Central

    Gao, Yong-Jing; Zhang, Ling; Samad, Omar Abdel; Suter, Marc R.; Yasuhiko, Kawasaki; Xu, Zhen-Zhong; Park, Jong-Yeon; Lind, Anne-Li; Ma, Qiufu; Ji, Ru-Rong

    2009-01-01

    Our previous study showed that activation of c-jun-N-terminal kinase (JNK) in spinal astrocytes plays an important role in neuropathic pain sensitization. We further investigated how JNK regulates neuropathic pain. In cultured astrocytes, TNF-α transiently activated JNK via TNF receptor-1. Cytokine array indicated that the chemokine CCL2/MCP-1 (monocyte chemoattractant protein-1) was strongly induced by the TNF-α/JNK pathway. MCP-1 upregulation by TNF-α was dose-dependently inhibited by the JNK inhibitors SP600125 and D-JNKI-1. Spinal injection of TNF-α produced JNK-dependent pain hypersensitivity and MCP-1 upregulation in the spinal cord. Further, spinal nerve ligation (SNL) induced persistent neuropathic pain and MCP-1 upregulation in the spinal cord, and both were suppressed by D-JNKI-1. Remarkably, MCP-1 was primarily induced in spinal cord astrocytes after SNL. Spinal administration of MCP-1 neutralizing antibody attenuated neuropathic pain. Conversely, spinal application of MCP-1 induced heat hyperalgesia and phosphorylation of extracellular signal-regulated kinase (ERK) in superficial spinal cord dorsal horn neurons, indicative of central sensitization (hyperactivity of dorsal horn neurons). Patch clamp recordings in lamina II neurons of isolated spinal cord slices showed that MCP-1 not only enhanced spontaneous excitatory synaptic currents (sEPSCs) but also potentiated NMDA- and AMPA-induced currents. Finally, the MCP-1 receptor CCR2 was expressed in neurons and some non-neuronal cells in the spinal cord. Taken together, we have revealed a previously unknown mechanism of MCP-1 induction and action. MCP-1 induction in astrocytes following JNK activation contributes to central sensitization and neuropathic pain facilitation by enhancing excitatory synaptic transmission. Inhibition of the JNK/MCP-1 pathway may provide a new therapy for neuropathic pain management. PMID:19339605

  15. JNK-induced MCP-1 production in spinal cord astrocytes contributes to central sensitization and neuropathic pain.

    PubMed

    Gao, Yong-Jing; Zhang, Ling; Samad, Omar Abdel; Suter, Marc R; Yasuhiko, Kawasaki; Xu, Zhen-Zhong; Park, Jong-Yeon; Lind, Anne-Li; Ma, Qiufu; Ji, Ru-Rong

    2009-04-01

    Our previous study showed that activation of c-jun-N-terminal kinase (JNK) in spinal astrocytes plays an important role in neuropathic pain sensitization. We further investigated how JNK regulates neuropathic pain. In cultured astrocytes, tumor necrosis factor alpha (TNF-alpha) transiently activated JNK via TNF receptor-1. Cytokine array indicated that the chemokine CCL2/MCP-1 (monocyte chemoattractant protein-1) was strongly induced by the TNF-alpha/JNK pathway. MCP-1 upregulation by TNF-alpha was dose dependently inhibited by the JNK inhibitors SP600125 (anthra[1,9-cd]pyrazol-6(2H)-one) and D-JNKI-1. Spinal injection of TNF-alpha produced JNK-dependent pain hypersensitivity and MCP-1 upregulation in the spinal cord. Furthermore, spinal nerve ligation (SNL) induced persistent neuropathic pain and MCP-1 upregulation in the spinal cord, and both were suppressed by D-JNKI-1. Remarkably, MCP-1 was primarily induced in spinal cord astrocytes after SNL. Spinal administration of MCP-1 neutralizing antibody attenuated neuropathic pain. Conversely, spinal application of MCP-1 induced heat hyperalgesia and phosphorylation of extracellular signal-regulated kinase in superficial spinal cord dorsal horn neurons, indicative of central sensitization (hyperactivity of dorsal horn neurons). Patch-clamp recordings in lamina II neurons of isolated spinal cord slices showed that MCP-1 not only enhanced spontaneous EPSCs but also potentiated NMDA- and AMPA-induced currents. Finally, the MCP-1 receptor CCR2 was expressed in neurons and some non-neuronal cells in the spinal cord. Together, we have revealed a previously unknown mechanism of MCP-1 induction and action. MCP-1 induction in astrocytes after JNK activation contributes to central sensitization and neuropathic pain facilitation by enhancing excitatory synaptic transmission. Inhibition of the JNK/MCP-1 pathway may provide a new therapy for neuropathic pain management.

  16. Reactive oxygen species mediate nitric oxide production through ERK/JNK MAPK signaling in HAPI microglia after PFOS exposure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Cheng; Nie, Xiaoke; Zhang, Yan

    2015-10-15

    Perfluorooctane sulfonate (PFOS), an emerging persistent contaminant that is commonly encountered during daily life, has been shown to exert toxic effects on the central nervous system (CNS). However, the molecular mechanisms underlying the neurotoxicity of PFOS remain largely unknown. It has been widely acknowledged that the inflammatory mediators released by hyper-activated microglia play vital roles in the pathogenesis of various neurological diseases. In the present study, we examined the impact of PFOS exposure on microglial activation and the release of proinflammatory mediators, including nitric oxide (NO) and reactive oxidative species (ROS). We found that PFOS exposure led to concentration-dependent NOmore » and ROS production by rat HAPI microglia. We also discovered that there was rapid activation of the ERK/JNK MAPK signaling pathway in the HAPI microglia following PFOS treatment. Moreover, the PFOS-induced iNOS expression and NO production were attenuated after the inhibition of ERK or JNK MAPK by their corresponding inhibitors, PD98059 and SP600125. Interestingly, NAC, a ROS inhibitor, blocked iNOS expression, NO production, and activation of ERK and JNK MAPKs, which suggested that PFOS-mediated microglial NO production occurs via a ROS/ERK/JNK MAPK signaling pathway. Finally, by exposing SH-SY5Y cells to PFOS-treated microglia-conditioned medium, we demonstrated that NO was responsible for PFOS-mediated neuronal apoptosis. - Highlights: • PFOS exposure induced expression of iNOS and production of NO in HAPI microglia. • PFOS induced the production of ROS in HAPI microglia. • ERK/JNK MAPK pathways were activated following PFOS exposure in HAPI microglia. • NO released by HAPI microglia participated in the apoptosis of SH-SY5Y cells.« less

  17. Protective Role of Taurine against Arsenic-Induced Mitochondria-Dependent Hepatic Apoptosis via the Inhibition of PKCδ-JNK Pathway

    PubMed Central

    Das, Joydeep; Ghosh, Jyotirmoy; Manna, Prasenjit; Sil, Parames C.

    2010-01-01

    Background Oxidative stress-mediated hepatotoxic effect of arsenic (As) is mainly due to the depletion of glutathione (GSH) in liver. Taurine, on the other hand, enhances intracellular production of GSH. Little is known about the mechanism of the beneficial role of taurine in As-induced hepatic pathophysiology. Therefore, in the present study we investigated its beneficial role in As-induced hepatic cell death via mitochondria-mediated pathway. Methodology/Principal Findings Rats were exposed to NaAsO2 (2 mg/kg body weight for 6 months) and the hepatic tissue was used for oxidative stress measurements. In addition, the pathophysiologic effect of NaAsO2 (10 µM) on hepatocytes was evaluated by determining cell viability, mitochondrial membrane potential and ROS generation. As caused mitochondrial injury by increased oxidative stress and reciprocal regulation of Bcl-2, Bcl-xL/Bad, Bax, Bim in association with increased level of Apaf-1, activation of caspase 9/3, cleavage of PARP protein and ultimately led to apoptotic cell death. In addition, As markedly increased JNK and p38 phosphorylation with minimal disturbance of ERK. Pre-exposure of hepatocytes to a JNK inhibitor SP600125 prevented As-induced caspase-3 activation, ROS production and loss in cell viability. Pre-exposure of hepatocytes to a p38 inhibitor SB2035, on the other hand, had practically no effect on these events. Besides, As activated PKCδ and pre-treatment of hepatocytes with its inhibitor, rottlerin, suppressed the activation of JNK indicating that PKCδ is involved in As-induced JNK activation and mitochondrial dependent apoptosis. Oral administration of taurine (50 mg/kg body weight for 2 weeks) both pre and post to NaAsO2 exposure or incubation of the hepatocytes with taurine (25 mM) were found to be effective in counteracting As-induced oxidative stress and apoptosis. Conclusions/Significance Results indicate that taurine treatment improved As-induced hepatic damages by inhibiting PKCδ-JNK

  18. A synthetic diosgenin primary amine derivative attenuates LPS-stimulated inflammation via inhibition of NF-κB and JNK MAPK signaling in microglial BV2 cells.

    PubMed

    Cai, Bangrong; Seong, Kyung-Joo; Bae, Sun-Woong; Chun, Changju; Kim, Won-Jae; Jung, Ji-Yeon

    2018-06-08

    Diosgenin, a precursor of steroid hormones in plants, is known to exhibit diverse pharmacological activities including anti-inflammatory properties. In this study, (3β, 25R)‑spirost‑5‑en‑3‑oxyl (2‑((2((2‑aminoethyl)amino)ethyl)amino)ethyl) carbamate (DGP), a new synthetic diosgenin derivative incorporating primary amine was used to investigate its anti-inflammatory effects and underlying mechanisms of action in lipopolysaccharide (LPS)-stimulated microglial BV2 cells. Pretreatment with DGP resulted in significant inhibition of nitric oxide (NO) synthesis, and down-regulation of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated microglial BV2 cells. In addition, DGP decreased the production of reactive oxygen species (ROS) and pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α). The inhibitory effects of DGP on these inflammatory mediators in LPS-stimulated microglial BV2 cells were regulated by NF-κB signaling through blocking p65 nuclear translocation and NF-κB p65/DNA binding activity. DGP also blocked the phosphorylation of c-Jun amino-terminal kinase (JNK), but not p38 kinase or extracellular signal-regulated kinases (ERK). The NF-κB inhibitor JSH-23 and JNK-specific inhibitor SP600125 significantly decreased NO production and IL-6 release in LPS-stimulated BV2 cells, respectively. The overall results demonstrate that DGP has anti-inflammatory effects on LPS-stimulated BV2 cells via inhibition of NF-κB and JNK activation, suggesting that DGP is a potential prophylactic agent in various neurodegenerative disorders. Copyright © 2018. Published by Elsevier B.V.

  19. Anti-Inflammatory Effects and Joint Protection in Collagen-Induced Arthritis after Treatment with IQ-1S, a Selective c-Jun N-Terminal Kinase Inhibitor

    PubMed Central

    Schepetkin, Igor A.; Kirpotina, Liliya N.; Hammaker, Deepa; Kochetkova, Irina; Khlebnikov, Andrei I.; Lyakhov, Sergey A.; Firestein, Gary S.

    2015-01-01

    c-Jun N-terminal kinases (JNKs) participate in many physiologic and pathologic processes, including inflammatory diseases. We recently synthesized the sodium salt of IQ-1S (11H-indeno[1,2-b]quinoxalin-11-one oxime) and demonstrated that it is a high-affinity JNK inhibitor and inhibits murine delayed-type hypersensitivity. Here we show that IQ-1S is highly specific for JNK and that its neutral form is the most abundant species at physiologic pH. Molecular docking of the IQ-1S syn isomer into the JNK1 binding site gave the best pose, which corresponded to the position of cocrystallized JNK inhibitor SP600125 (1,9-pyrazoloanthrone). Evaluation of the therapeutic potential of IQ-1S showed that it inhibited matrix metalloproteinase 1 and 3 gene expression induced by interleukin-1β in human fibroblast-like synoviocytes and significantly attenuated development of murine collagen-induced arthritis (CIA). Treatment with IQ-1S either before or after induction of CIA resulted in decreased clinical scores, and joint sections from IQ-1S–treated CIA mice exhibited only mild signs of inflammation and minimal cartilage loss compared with those from control mice. Collagen II–specific antibody responses were also reduced by IQ-1S treatment. By contrast, the inactive ketone derivative 11H-indeno[1,2-b]quinoxalin-11-one had no effect on CIA clinical scores or collagen II–specific antibody titers. IQ-1S treatment also suppressed proinflammatory cytokine and chemokine levels in joints and lymph node cells. Finally, treatment with IQ-1S increased the number of Foxp3+CD4+CD25+ regulatory T cells in lymph nodes. Thus, IQ-1S can reduce inflammation and cartilage loss associated with CIA and can serve as a small-molecule modulator for mechanistic studies of JNK function in rheumatoid arthritis. PMID:25784649

  20. Arsenic trioxide mediates HAPI microglia inflammatory response and subsequent neuron apoptosis through p38/JNK MAPK/STAT3 pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mao, Jiamin

    Arsenic is a widely distributed toxic metalloid all over the world. Inorganic arsenic species are supposed to affect astrocytic functions and to cause neuron apoptosis in CNS. Microglias are the key cell type involved in innate immune responses in CNS, and microglia activation has been linked to inflammation and neurotoxicity. In this study, using ELISA, we showed that Arsenic trioxide up-regulated the expression and secretion of IL-1β in a dose-dependent manner and a time-dependent manner in cultured HAPI microglia cells. The secretion of IL-1β caused the apoptosis of SH-SY5Y. These pro-inflammatory responses were inhibited by the STAT3 blocker, AG490 andmore » P38/JNK MAPK blockers SB202190, SP600125. Further, Arsenic trioxide exposure could induce phosphorylation and activation of STAT3, and the translocation of STAT3 from the cytosol to the nucleus in this HAPI microglia cell line. Thus, the STAT3 signaling pathway can be activated after Arsenic trioxide treatment. However, P38/JNK MAPK blockers SB202190, SP600125 also obviously attenuated STAT3 activation and transnuclear transport induced by Arsenic trioxide. In concert with these results, we highlighted that the secretion of IL-1β and STAT3 activation induced by Arsenic trioxide can be mediated by elevation of P38/JNK MAPK in HAPI microglia cells and then induced the toxicity of neurons. - Highlights: • Arsenic trioxide exposure induced expression of IL-β in HAPI microglia. • Arsenic trioxide exposure induced activation of MAPK pathways in HAPI microglia. • Arsenic trioxide exposure induced activation of STAT3 pathways in HAPI microglia. • The expression of IL-β though P38/JNK MAPK/STAT3 pathways in HAPI microglia.« less

  1. Modulation of iridovirus-induced apoptosis by endocytosis, early expression, JNK, and apical caspase

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chitnis, Nilesh S.; D'Costa, Susan M.; Paul, Eric R.

    Chilo iridescent virus (CIV) is the type species for the family Iridoviridae, which are large, isometric, cytoplasmic dsDNA viruses. We examined the mechanism of apoptosis induction by CIV. High CIV doses (CIV{sub XS}; 400 {mu}g/ml), UV-irradiated virus (CIV{sub UV}; 10 {mu}g/ml) and CVPE (CIV protein extract; 10 {mu}g/ml) induced apoptosis in 60% of treated Choristoneura fumiferana (IPRI-CF-124T) cells. Normal doses of infectious CIV (10 {mu}g/ml) induced apoptosis in only 10% of C. fumiferana (CF) cells. Apoptosis was inhibited by Z-IETD-FMK, an apical caspase inhibitor, indicating that CIV-induced apoptosis requires caspase activity. The putative caspase in CF cells was designated Cf-caspase-i.more » CIV{sub UV} or CVPE enhanced Cf-caspase-i activity by 80% at 24 h relative to mock-treated cells. Since the MAP kinase pathway induces or inhibits apoptosis depending on the context, we used JNK inhibitor SP600125 and demonstrated drastic suppression of CVPE-induced apoptosis. Thus, the JNK signaling pathway is significant for apoptosis in this system. Virus interaction with the cell surface was not sufficient for apoptosis since CIV{sub UV} particles bound to polysterene beads failed to induce apoptosis. Endocytosis inhibitors (bafilomycin or ammonium chloride) negated apoptosis induction by CIV{sub UV}, CIV{sub XS} or CVPE indicating that entry through this mode is required. Given the weak apoptotic response to infectious CIV, we postulated that viral gene expression inhibited apoptosis. CIV infection of cells pretreated with cycloheximide induced apoptosis in 69% of the cells compared to 10% in normal infections. Furthermore, blocking viral DNA replication with aphidicolin or phosphonoacetic acid suppressed apoptosis and Cf-caspase-i activity, indicating that early viral expression is necessary for inhibition of apoptosis, and de novo synthesis of viral proteins is not required for induction. We show for the first time that, in a member of the family

  2. Bornyl caffeate induces apoptosis in human breast cancer MCF-7 cells via the ROS- and JNK-mediated pathways

    PubMed Central

    Yang, Chuan-bin; Pei, Wei-jing; Zhao, Jia; Cheng, Yuan-yuan; Zheng, Xiao-hui; Rong, Jian-hui

    2014-01-01

    Aim: To investigate the effects of bornyl caffeate discovered in several species of plant on human breast cancer cells in vitro and the underlying mechanisms. Methods: Human breast cancer cell line MCF-7 and other tumor cell lines (T47D, HepG2, HeLa, and PC12) were tested. Cell viability was determined using MTT assay, and apoptosis was defined by monitoring the morphology of the nuclei and staining with Annexin V-FITC. Mitochondrial membrane potential (MMP) was measured using JC-1 under fluorescence microscopy. Intracellular reactive oxygen species (ROS) were assessed by flow cytometry. The expression of apoptosis-associated proteins was determined by Western blotting analysis. Results: Bornyl caffeate (10, 25, and 50 μmol/L) suppressed the viability of MCF-7 cells in dose- and time-dependent manners, but neither caffeic acid nor borneol showed cytotoxicity at a concentration of 50 μmol/L. Bornyl caffeate also exerted cytotoxicity to HepG2, Hela, T47D, and PC12 cells. Bornyl caffeate dose-dependently induced apoptosis of MCF-7 cells, increased the expression of Bax and decreased the expression of Bcl-xl, resulting in the disruption of MMP and subsequent activation of caspase-3. Moreover, bornyl caffeate triggered the formation of ROS and activated p38 and c-Jun JNK. In MCF-7 cells, the cytotoxicity of bornyl caffeate was significantly attenuated by SB203580 (p38 inhibitor), SP600125 (JNK inhibitor), z-VAD (pan-caspase inhibitor) or the thiol antioxidant L-NAC. Conclusion: Bornyl caffeate exerts non-selective cytotoxicity against cancer cells of different origin in vitro. The compound induces apoptosis in human breast cancer MCF-7 cells via the ROS- and JNK-mediated pathways. PMID:24335836

  3. Fucoidan/FGF-2 induces angiogenesis through JNK- and p38-mediated activation of AKT/MMP-2 signalling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Beom Su; Bonecell Biotech Inc., 77, Dunsan-dong, Seo-gu, Daejeon 302-830; Park, Ji-Yun

    2014-08-08

    -regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38, and AKT. MMP-2 activation was also significantly increased. Specific inhibitors of p38 (SB203580) and JNK (SP600125) inhibited tube formation and wound healing, while an ERK inhibitor (PD98059) did not. MMP-2 activation and AKT phosphorylation were also attenuated and associated with the suppression of p38 and JNK phosphorylation, but not with that of ERK. These results indicate that fucoidan, in the presence of FGF-2, induces angiogenesis through AKT/MMP-2 signalling by activating p38 and JNK. These findings provide basic molecular information on the effect of fucoidan on angiogenesis in the presence of FGF-2.« less

  4. Functionally Selective Signaling for Morphine and Fentanyl Antinociception and Tolerance Mediated by the Rat Periaqueductal Gray

    PubMed Central

    Morgan, Michael M.; Reid, Rachel A.; Saville, Kimber A.

    2014-01-01

    Functionally selective signaling appears to contribute to the variability in mechanisms that underlie tolerance to the antinociceptive effects of opioids. The present study tested this hypothesis by examining the contribution of G protein-coupled receptor kinase (GRK)/Protein kinase C (PKC) and C-Jun N-terminal kinase (JNK) activation on both the expression and development of tolerance to morphine and fentanyl microinjected into the ventrolateral periaqueductal gray of the rat. Microinjection of morphine or fentanyl into the periaqueductal gray produced a dose-dependent increase in hot plate latency. Microinjection of the non-specific GRK/PKC inhibitor Ro 32-0432 into the periaqueductal gray to block mu-opioid receptor phosphorylation enhanced the antinociceptive effect of morphine but had no effect on fentanyl antinociception. Microinjection of the JNK inhibitor SP600125 had no effect on morphine or fentanyl antinociception, but blocked the expression of tolerance to repeated morphine microinjections. In contrast, a microinjection of Ro 32-0432 blocked the expression of fentanyl, but not morphine tolerance. Repeated microinjections of Ro 32-0432 blocked the development of morphine tolerance and inhibited fentanyl antinociception whether rats were tolerant or not. Repeated microinjections of SP600125 into the periaqueductal gray blocked the development of tolerance to both morphine and fentanyl microinjections. These data demonstrate that the signaling molecules that contribute to tolerance vary depending on the opioid and methodology used to assess tolerance (expression vs. development of tolerance). This signaling difference is especially clear for the expression of tolerance in which JNK contributes to morphine tolerance and GRK/PKC contributes to fentanyl tolerance. PMID:25503060

  5. HER2-induced metastasis is mediated by AKT/JNK/EMT signaling pathway in gastric cancer

    PubMed Central

    Choi, Yiseul; Ko, Young San; Park, Jinju; Choi, Youngsun; Kim, Younghoon; Pyo, Jung-Soo; Jang, Bo Gun; Hwang, Douk Ho; Kim, Woo Ho; Lee, Byung Lan

    2016-01-01

    AIM To investigated the relationships between HER2, c-Jun N-terminal kinase (JNK) and protein kinase B (AKT) with respect to metastatic potential of HER2-positive gastric cancer (GC) cells. METHODS Immunohistochemistry was performed on tissue array slides containing 423 human GC specimens. Using HER2-positve GC cell lines SNU-216 and NCI-N87, HER2 expression was silenced by RNA interference, and the activations of JNK and AKT were suppressed by SP600125 and LY294002, respectively. Transwell assay, Western blot, semi-quantitative reverse transcription-polymerase chain reaction and immunofluorescence staining were used in cell culture experiments. RESULTS In GC specimens, HER2, JNK, and AKT activations were positively correlated with each other. In vitro analysis revealed a positive regulatory feedback loop between HER2 and JNK in GC cell lines and the role of JNK as a downstream effector of AKT in the HER2/AKT signaling pathway. JNK inhibition suppressed migratory capacity through reversing EMT and dual inhibition of JNK and AKT induced a more profound effect on cancer cell motility. CONCLUSION HER2, JNK and AKT in human GC specimens are positively associated with each other. JNK and AKT, downstream effectors of HER2, co-operatively contribute to the metastatic potential of HER2-positive GC cells. Thus, targeting of these two molecules in combination with HER2 downregulation may be a good approach to combat HER2-positive GC. PMID:27895401

  6. Calcium/Ask1/MKK7/JNK2/c-Src signalling cascade mediates disruption of intestinal epithelial tight junctions by dextran sulfate sodium.

    PubMed

    Samak, Geetha; Chaudhry, Kamaljit K; Gangwar, Ruchika; Narayanan, Damodaran; Jaggar, Jonathan H; Rao, RadhaKrishna

    2015-02-01

    Disruption of intestinal epithelial tight junctions is an important event in the pathogenesis of ulcerative colitis. Dextran sodium sulfate (DSS) induces colitis in mice with symptoms similar to ulcerative colitis. However, the mechanism of DSS-induced colitis is unknown. We investigated the mechanism of DSS-induced disruption of intestinal epithelial tight junctions and barrier dysfunction in Caco-2 cell monolayers in vitro and mouse colon in vivo. DSS treatment resulted in disruption of tight junctions, adherens junctions and actin cytoskeleton leading to barrier dysfunction in Caco-2 cell monolayers. DSS induced a rapid activation of c-Jun N-terminal kinase (JNK), and the inhibition or knockdown of JNK2 attenuated DSS-induced tight junction disruption and barrier dysfunction. In mice, DSS administration for 4 days caused redistribution of tight junction and adherens junction proteins from the epithelial junctions, which was blocked by JNK inhibitor. In Caco-2 cell monolayers, DSS increased intracellular Ca(2+) concentration, and depletion of intracellular Ca(2+) by 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis(acetoxymethyl ester) (BAPTA/AM) or thapsigargin attenuated DSS-induced JNK activation, tight junction disruption and barrier dysfunction. Knockdown of apoptosis signal-regulated kinase 1 (Ask1) or MKK7 blocked DSS-induced tight junction disruption and barrier dysfunction. DSS activated c-Src by a Ca2+ and JNK-dependent mechanism. Inhibition of Src kinase activity or knockdown of c-Src blocked DSS-induced tight junction disruption and barrier dysfunction. DSS increased tyrosine phosphorylation of occludin, zonula occludens-1 (ZO-1), E-cadherin and β-catenin. SP600125 abrogated DSS-induced tyrosine phosphorylation of junctional proteins. Recombinant JNK2 induced threonine phosphorylation and auto-phosphorylation of c-Src. The present study demonstrates that Ca(2+)/Ask1/MKK7/JNK2/cSrc signalling cascade mediates DSS-induced tight

  7. Electroacupuncture attenuates mechanical allodynia by suppressing the spinal JNK1/2 pathway in a rat model of inflammatory pain.

    PubMed

    Du, Jun-Ying; Fang, Jian-Qiao; Liang, Yi; Fang, Jun-Fan

    2014-09-01

    Electroacupuncture (EA) has a substantial analgesic effect on inflammatory pain induced by complete Freund's adjuvant (CFA). The activation of the c-Jun N-terminal kinase 1/2 (JNK1/2) signal transduction pathway in the spinal cord is associated with inflammatory pain. However, the relationship between EA's analgesic effect and the JNK1/2 signal transduction pathway in the inflammatory pain remain unclear. In the present study, we used the established rat model of CFA-induced inflammatory pain to investigate the role of the spinal JNK1/2 pathway in EA-mediated analgesia. We observed a decrease in paw withdrawal thresholds and an increase in paw edema at 1 and 3 days after injecting CFA into the right hindpaw. CFA, 3 days after injection, upregulated expression of phospho-c-Jun N-terminal kinase1/2 (p-JNK1/2) protein and its downstream targets, the transcriptional regulators p-c-Jun and activator protein-1 (AP-1), as well as cyclooxygenase-2 (COX-2) and the transient receptor potential vanilloid 1 (TRPV1). EA significantly alleviated CFA-induced inflammatory pain. In addition, EA reduced p-JNK1/2 protein levels and COX-2 mRNA expressions, a degree of down-regulated p-c-Jun protein level and AP-1 DNA binding activity in the spinal dorsal horn of CFA-administered animals, but it had no effect on TRPV1 mRNA expression. Furthermore, EA and the JNK inhibitor SP600125 synergistically inhibited CFA-induced hyperalgesia and suppressed the COX-2 mRNA expression in the spinal dorsal horn. Our findings indicate that EA alleviates inflammatory pain behavior, at least in part, by reducing COX-2 expression in the spinal cord via the JNK1/2 signaling pathway. Inactivation of the spinal JNK1/2 signal transduction pathway maybe the potential mechanism of EA's antinociception in the inflammatory pain model. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. A ginseng metabolite, compound K, induces autophagy and apoptosis via generation of reactive oxygen species and activation of JNK in human colon cancer cells

    PubMed Central

    Kim, A D; Kang, K A; Kim, H S; Kim, D H; Choi, Y H; Lee, S J; Kim, H S; Hyun, J W

    2013-01-01

    Compound K (20-O-(β-D-glucopyranosyl)-20(S)-protopanaxadiol) is an active metabolite of ginsenosides and induces apoptosis in various types of cancer cells. This study investigated the role of autophagy in compound K-induced cell death of human HCT-116 colon cancer cells. Compound K activated an autophagy pathway characterized by the accumulation of vesicles, the increased positive acridine orange-stained cells, the accumulation of LC3-II, and the elevation of autophagic flux. Whereas blockade of compound K-induced autophagy by 3-methyladenein and bafilomycin A1 significantly increased cell viability. In addition, compound K augmented the time-dependent expression of the autophagy-related proteins Atg5, Atg6, and Atg7. However, knockdown of Atg5, Atg6, and Atg7 markedly inhibited the detrimental impact of compound K on LC3-II accumulation and cell vitality. Compound K-provoked autophagy was also linked to the generation of intracellular reactive oxygen species (ROS); both of these processes were mitigated by the pre-treatment of cells with the antioxidant N-acetylcysteine. Moreover, compound K activated the c-Jun NH2-terminal kinase (JNK) signaling pathway, whereas downregulation of JNK by its specific inhibitor SP600125 or by small interfering RNA against JNK attenuated autophagy-mediated cell death in response to compound K. Compound K also provoked apoptosis, as evidenced by an increased number of apoptotic bodies and sub-G1 hypodiploid cells, enhanced activation of caspase-3 and caspase-9, and modulation of Bcl-2 and Bcl-2-associated X protein expression. Notably, compound K-stimulated autophagy as well as apoptosis was induced by disrupting the interaction between Atg6 and Bcl-2. Taken together, these results indicate that the induction of autophagy and apoptosis by compound K is mediated through ROS generation and JNK activation in human colon cancer cells. PMID:23907464

  9. Anti-Inflammatory Effects and Joint Protection in Collagen-Induced Arthritis after Treatment with IQ-1S, a Selective c-Jun N-Terminal Kinase Inhibitor.

    PubMed

    Schepetkin, Igor A; Kirpotina, Liliya N; Hammaker, Deepa; Kochetkova, Irina; Khlebnikov, Andrei I; Lyakhov, Sergey A; Firestein, Gary S; Quinn, Mark T

    2015-06-01

    c-Jun N-terminal kinases (JNKs) participate in many physiologic and pathologic processes, including inflammatory diseases. We recently synthesized the sodium salt of IQ-1S (11H-indeno[1,2-b]quinoxalin-11-one oxime) and demonstrated that it is a high-affinity JNK inhibitor and inhibits murine delayed-type hypersensitivity. Here we show that IQ-1S is highly specific for JNK and that its neutral form is the most abundant species at physiologic pH. Molecular docking of the IQ-1S syn isomer into the JNK1 binding site gave the best pose, which corresponded to the position of cocrystallized JNK inhibitor SP600125 (1,9-pyrazoloanthrone). Evaluation of the therapeutic potential of IQ-1S showed that it inhibited matrix metalloproteinase 1 and 3 gene expression induced by interleukin-1β in human fibroblast-like synoviocytes and significantly attenuated development of murine collagen-induced arthritis (CIA). Treatment with IQ-1S either before or after induction of CIA resulted in decreased clinical scores, and joint sections from IQ-1S-treated CIA mice exhibited only mild signs of inflammation and minimal cartilage loss compared with those from control mice. Collagen II-specific antibody responses were also reduced by IQ-1S treatment. By contrast, the inactive ketone derivative 11H-indeno[1,2-b]quinoxalin-11-one had no effect on CIA clinical scores or collagen II-specific antibody titers. IQ-1S treatment also suppressed proinflammatory cytokine and chemokine levels in joints and lymph node cells. Finally, treatment with IQ-1S increased the number of Foxp3(+)CD4(+)CD25(+) regulatory T cells in lymph nodes. Thus, IQ-1S can reduce inflammation and cartilage loss associated with CIA and can serve as a small-molecule modulator for mechanistic studies of JNK function in rheumatoid arthritis. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  10. Puerarin reduces apoptosis in rat hippocampal neurons culturea in high glucose medium by modulating the p38 mitogen activated protein kinase and c-Jun N-terminal kinase signaling pathways.

    PubMed

    Xu, Xiaohan; Wang, Jingbo; Zhang, Hong; Tian, Guoqing; Liu, Yuqin

    2016-02-01

    To investigate the neuroprotective etfect of puerarin on rat hippocampal neurons cultured in high glucose medium, and to examine the role of the p38 mitogen activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) signaling pathways in this effect. Primary cultures of hippocampal neurons were prepared from newborn Sprague Dawley rats. Neuron-specific enolase immunocytochemistry was used to identify neurons. The neurons were cultured with normal medium (control group) or with high-glucose medium (high-glucose group), and puerarin (puerarin group), a p38 MAPK inhibitor (SB239063; p38 MAPK inhibitor group) or a JNK inhibitor (SP600125; JNK inhibitor group) were added. After 72 h of treatment, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was performed to detect apoptosis, and western blotting was used to assess protein levels of p-p38, p38, p-JNK and JNK. In the high-glucose group, the neuronal apoptosis rate and the p-p38/p38 and p-JNK/JNK ratios were higher than in the control group. The p38 MAPK and JNK inhibitors prevented this increase in the apoptosis rate. The apoptosis rates in the puerarin group, the p38 MAPK inhibitor group and the JNK inhibitor group were significantly decreased compared with the high-glucose group. Moreover, protein levels of p-p38 and p-JNK were significantly reduced, and the p-p38/p38 and p-JNK/JNK ratios were decreased in the puerarin group compared with the high-glucose group. In addition, compared with the high-glucose group, p-p38 levels and the p-p38/p38 ratio were reduced in the p38 MAPK inhibitor group, and p-JNK levels and the p-JNK/JNK ratio were decreased in the JNK inhibitor group. Puerarin attenuates neuronal apoptosis induced by high glucose by reducing the phosphorylation of p38 and JNK.

  11. Acute inhibition of central c-Jun N-terminal kinase restores hypothalamic insulin signalling and alleviates glucose intolerance in diabetic mice.

    PubMed

    Benzler, J; Ganjam, G K; Legler, K; Stöhr, S; Krüger, M; Steger, J; Tups, A

    2013-05-01

    The hypothalamus has been identified as a main insulin target tissue for regulating normal body weight and glucose metabolism. Recent observations suggest that c-Jun-N-terminal kinase (JNK)-signalling plays a crucial role in the development of obesity and insulin resistance because neuronal JNK-1 ablation in the mouse prevented high-fat diet-induced obesity (DIO) and increased energy expenditure, as well as insulin sensitivity. In the present study, we investigated whether central JNK inhibition is associated with sensitisation of hypothalamic insulin signalling in mice fed a high-fat diet for 3 weeks and in leptin-deficient mice. We determined whether i.c.v. injection of a pharmacological JNK-inhibitor (SP600125) improved impaired glucose homeostasis. By immunohistochemistry, we first observed that JNK activity was increased in the arcuate nucleus (ARC) and the ventromedial hypothalamus (VMH) in both mouse models, relative to normoglycaemic controls. This suggests that up-regulation of JNK in these regions is associated with glucose intolerance and obesity, independent of leptin levels. Acute i.c.v. injection of SP600125 ameliorated glucose tolerance within 30 min in both leptin-deficient and DIO mice. Given the acute nature of i.c.v. injections, these effects cannot be attributed to changes in food intake or energy balance. In a hypothalamic cell line, and in the ARC and VMH of leptin-deficient mice, JNK inhibition by SP600125 consistently improved impaired insulin signalling. This was determined by a reduction of phospho-insulin receptor substrate-1 [IRS-1(Ser612)] protein in a hypothalamic cell line and a decline in the number of pIRS-1(Ser612) immunoreactive cells in the ARC and VMH. Serine 612 phosphorylation of IRS-1 is assumed to negatively regulate insulin signalling. In leptin-deficient mice, in both nuclei, central inhibition of JNK increased the number of cells immunoreactive for phospho-Akt (Ser473) and phospho-GSK-3β (Ser9), which are important

  12. Dihydromyricetin alleviates carbon tetrachloride-induced acute liver injury via JNK-dependent mechanism in mice.

    PubMed

    Xie, Jun; Liu, Jie; Chen, Tu-Ming; Lan, Qing; Zhang, Qing-Yu; Liu, Bin; Dai, Dong; Zhang, Wei-Dong; Hu, Li-Ping; Zhu, Run-Zhi

    2015-05-14

    To assess the effects of dihydromyricetin (DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride (CCl4) treatment. C57 BL/6 mice were used in this study. Mice were orally administered with DHM (150 mg/kg) for 4 d after CCl4 treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl4 treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, and superoxide dismutase (SOD). Inflammatory cytokines, such as interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen (PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis was measured by TUNEL assay. Furthermore, apoptosis proteins Caspases-3, 6, 8, and 9 were detected by Western blot. SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-α pathways. DHM showed a strong anti-inflammatory effect on CCl4-induced liver injury in mice. DHM could significantly decrease serum ALT, AST, IL-1β, IL-6 and TNF-α and increase serum albumin, SOD and liver SOD compared to the control group after CCl4 treatment (P < 0.05). PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control (348.9 ± 56.0 vs 107.1 ± 31.4, P < 0.01). TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control (365.4 ± 99.4 vs 90.5 ± 13.8, P < 0.01). Caspase activity detection showed that DHM could reduce the activities of Caspases- 8, 3, 6 and 9 compared to the control (P < 0.05). The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-α expression. However, DHM could not affect

  13. Vitamin K3-2,3-epoxide induction of apoptosis with activation of ROS-dependent ERK and JNK protein phosphorylation in human glioma cells.

    PubMed

    Wu, Jender; Chien, Chih-Chiang; Yang, Liang-Yo; Huang, Guan-Cheng; Cheng, Min-Chi; Lin, Che-Tong; Shen, Shing-Chuan; Chen, Yen-Chou

    2011-08-15

    2-Methyl-1,4-naphthoquinone (menadione or vitamin K3; EPO) and K3-2,3-epoxide (EPO1), but not vitamin K3-3-OH (EPO2), exhibited cytotoxicity that caused DNA fragmentation and chromatin condensation in U87 and C6 cells. EPO1 showed more-potent cytotoxicity than EPO, and the IC(50) values of EPO and EPO1 in U87 cells were 37.5 and 15.7μM, respectively. Activation of caspase 3 enzyme activity with cleavage of caspase 3 protein was detected in EPO1-treated U87 and C6 cells, and the addition of the caspase 3 peptidyl inhibitor, DEVD-FMK, reduced the cytotoxic effect of EPO1. An increase in the intracellular ROS level by EPO1 was observed in the DCHF-DA analysis, and EPO1-induced apoptosis and caspase 3 protein cleavage were prevented by adding the antioxidant, N-acetyl-cysteine (NAC), with decreased ROS production elicited by EPO1. Activation of ERK and JNK, but not p38, via phosphorylation induction was identified in EPO1- but not EPO- or EPO2-treated U87 and C6 cells, and this was blocked by adding NAC. However, the ERK inhibitor, PD98059, and the JNK inhibitor, SP600125, showed no effect on EPO1-induced cytotoxicity in either cell type. Our findings demonstrate that 2,3-epoxide substitution significantly potentiates the apoptotic effect of vitamin K3 via stimulating ROS production, which may be useful in the chemotherapy of glioblastoma cells. Copyright © 2011. Published by Elsevier Ireland Ltd.

  14. Thrombin/Matrix Metalloproteinase-9-Dependent SK-N-SH Cell Migration is Mediated Through a PLC/PKC/MAPKs/NF-κB Cascade.

    PubMed

    Yang, Chien-Chung; Lin, Chih-Chung; Chien, Peter Tzu-Yu; Hsiao, Li-Der; Yang, Chuen-Mao

    2016-11-01

    Thrombin has been known to activate inflammatory genes including matrix metalloproteinases (MMPs). The elevated expression of MMP-9 has been observed in patients with neuroinflammatory diseases and may contribute to the pathology of brain diseases. However, the mechanisms underlying thrombin-induced MMP-9 expression in SK-N-SH cells remain unknown. The effects of thrombin on MMP-9 expression were examined in SK-N-SH cells by gelatin zymography, Western blot, real-time PCR, promoter activity assay, and cell migration assay. The detailed mechanisms were analyzed by using pharmacological inhibitors and small intefering RNA (siRNA) transfection. Here, we demonstrated that thrombin induced the expression of proform MMP-9 and migration of SK-N-SH cells, which were attenuated by pretreatment with the inhibitor of thrombin (PPACK), Gq (GPA2A), PC-PLC (D609), PI-PLC (ET-18-OCH 3 ), nonselective protien kinase C (PKC, GF109203X), PKCα/βII (Gö6983), PKCδ (Rottlerin), p38 mitogen-activated protein kinases (MAPK) (SB202190), JNK1/2 (SP600125), or NF-κB (Bay11-7082 or Helenalin) and transfection with siRNA of Gq, PKCα, PKCβ, PKCδ, p38, JNK1/2, IKKα, IKKβ, or p65. Moreover, thrombin-stimulated PKCα/βII, PKCδ, p38 MAPK, JNK1/2, or p65 phosphorylation was abrogated by their respective inhibitor of PPACK, GPA2A, D609, ET-18-OCH 3 , Gö6983, Rottlerin, SB202190, SP600125, Bay11-7082, or Helenalin. Pretreatment with these inhibitors or transfection with MMP-9 siRNA also blocked thrombin-induced SK-N-SH cell migration. Our results show that thrombin stimulates a Gq/PLC/PKCs/p38 MAPK and JNK1/2 cascade, which in turn triggers NF-κB activation and ultimately induces MMP-9 expression and cell migration in SK-N-SH cells.

  15. Arsenic trioxide inhibits Ewing's sarcoma cell invasiveness by targeting p38(MAPK) and c-Jun N-terminal kinase.

    PubMed

    Zhang, Shuai; Guo, Wei; Ren, Ting-Ting; Lu, Xin-Chang; Tang, Guo-Qing; Zhao, Fu-Long

    2012-01-01

    Ewing's sarcoma is the second most frequent primary malignant bone tumor, mainly affecting children and young adults. The notorious metastatic capability of this tumor aggravates patient mortality and remains a problem to be overcome. We investigated the effect of arsenic trioxide (As₂O₃) on the metastasis capability of Ewing's sarcoma cells. We performed 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide assays to choose appropriate concentrations of As₂O₃ for the experiments. Migration, invasion, and adhesion assays were performed to assess the effect of As₂O₃ on the metastasis of Ewing's sarcoma. Immunofluorescent staining was used to observe cytoskeleton reorganization in Ewing's sarcoma cells treated with As₂O₃. Changes in matrix metalloproteinase-9 expression and the mitogen-activated protein kinase (MAPK) pathway were investigated using western blot. Inhibitors of p38(MAPK) (sb202190) and c-Jun NH₂-terminal kinase (JNK, sp600125) were used in invasion assays to determine the effect of p38(MAPK) and JNK. We found that As₂O₃ may markedly inhibit the migration and invasion capacity of Ewing's sarcoma cells with structural rearrangements of the actin cytoskeleton. The expressions of matrix metalloproteinase-9, phosphor-p38(MAPK), and phosphor-JNK were suppressed by As₂O₃ treatment in a dose-dependent manner. The inhibitors of p38(MAPK) (sb202190) and JNK (sp600125) enhanced the inhibition induced by As₂O₃, which was counteracted by anisomycin, an activating agent of p38(MAPK) and JNK. Taken together, our results demonstrate that As₂O₃ can inhibit the metastasis capability of RD-ES and A-673 cells and may have new therapeutic value for Ewing's sarcoma.

  16. Mycophenolic acid attenuates tumor necrosis factor-alpha-induced endothelin-1 production in human aortic endothelial cells.

    PubMed

    Yang, Won Seok; Lee, Joo Mi; Han, Nam Jeong; Kim, Yoon Ji; Chang, Jai Won; Park, Su-Kil

    2010-07-01

    Atherosclerotic cardiovascular disease is the major cause of morbidity and mortality in solid organ transplant recipients. Endothelin-1 (ET-1) is implicated in the pathogenesis of atherosclerosis and is one of the potential therapeutic targets. This study was conducted to evaluate the effect of mycophenolic acid (MPA), an immunosuppressant for the transplant recipients, on tumor necrosis factor-alpha (TNF-alpha)-induced ET-1 production in aortic endothelial cells. In cultured human aortic endothelial cells, TNF-alpha increased ET-1 through AP-1 and NF-kappaB, whereas MPA attenuated it by reducing both AP-1 and NF-kappaB DNA-binding activities. TNF-alpha increased ET-1 via c-Jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), but not extracellular signal-regulated kinase. N-acetylcysteine that downregulated TNF-alpha-induced reactive oxygen species (ROS) inhibited JNK activation, but not p38 MAPK. N-acetylcysteine, SP600125 (JNK inhibitor) and SB203580 (p38 MAPK inhibitor) attenuated TNF-alpha-induced DNA-binding activities of both AP-1 and NF-kappaB. MPA inhibited JNK and p38 MAPK activations as well as ROS generation. N-acetylcysteine, SP600125, SB203580 and MPA had no effect on either TNF-alpha-induced IkappaBalpha degradation or p65 nuclear translocation, but attenuated p65 Ser276 phosphorylation. MPA attenuated TNF-alpha-induced ET-1 production through inhibitions of ROS-dependent JNK and ROS-independent p38 MAPK that regulated NF-kappaB as well as AP-1. These findings suggest that MPA could have an effect of amelioration of atherosclerosis. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  17. Activation of JNK and IRE1 is critically involved in tanshinone I-induced p62 dependent autophagy in malignant pleural mesothelioma cells: implication of p62 UBA domain

    PubMed Central

    Yoon, Sangwook; Won, Gunho; Kim, Chang Geun; Jung, Ji Hoon; Kim, Sung-Hoon

    2017-01-01

    The aim of present study is to elucidate autophagic mechanism of tanshinone I (Tan I) in H28 and H2452 mesothelioma cells. Herein, Tan I exerted cytotoxicity with autophagic features of autophagy protein 5 (ATG5)/ microtubule-associated protein 1A/1B-light chain 3II (LC3 II) activation, p62/sequestosome 1 (SQSTM1) accumulation and increased number of LC3II punctae, acridine orange-stained cells and autophagic vacuoles. However, 3-methyladenine (3MA) and NH4Cl increased cytotoxicity in Tan I treated H28 cells. Furthermore, autophagy flux was enhanced in Tan I-treated H28 cells transfected by RFP-GFP-LC3 constructs, with colocalization of GFP-LC3 punctae with LAMP1 or Lysotracker. Interestingly, C-terminal UBA domain is required for Tan 1 induced aggregation of p62 in H28 cells. Notably, Tan I upregulated CCAAT-enhancer-binding protein homologous protein (CHOP), inositol-requiring protein-1 (IRE1) and p-c-Jun N-terminal kinase (p-JNK), but silencing of IRE1 or p62 and JNK inhibitor SP600125 blocked the LC3II accumulation in Tan I-treated H28 cells. Overall, these findings demonstrate that Tan I exerts antitumor activity through a compromise between apoptosis and p62/SQSTM1-dependent autophagy via activation of JNK and IRE 1 in malignant mesothelioma cells. PMID:28212571

  18. Activation of JNK and IRE1 is critically involved in tanshinone I-induced p62 dependent autophagy in malignant pleural mesothelioma cells: implication of p62 UBA domain.

    PubMed

    Lee, Jihyun; Sohn, Eun Jung; Yoon, Sangwook; Won, Gunho; Kim, Chang Geun; Jung, Ji Hoon; Kim, Sung-Hoon

    2017-04-11

    The aim of present study is to elucidate autophagic mechanism of tanshinone I (Tan I) in H28 and H2452 mesothelioma cells. Herein, Tan I exerted cytotoxicity with autophagic features of autophagy protein 5 (ATG5)/ microtubule-associated protein 1A/1B-light chain 3II (LC3 II) activation, p62/sequestosome 1 (SQSTM1) accumulation and increased number of LC3II punctae, acridine orange-stained cells and autophagic vacuoles. However, 3-methyladenine (3MA) and NH4Cl increased cytotoxicity in Tan I treated H28 cells. Furthermore, autophagy flux was enhanced in Tan I-treated H28 cells transfected by RFP-GFP-LC3 constructs, with colocalization of GFP-LC3 punctae with LAMP1 or Lysotracker. Interestingly, C-terminal UBA domain is required for Tan 1 induced aggregation of p62 in H28 cells. Notably, Tan I upregulated CCAAT-enhancer-binding protein homologous protein (CHOP), inositol-requiring protein-1 (IRE1) and p-c-Jun N-terminal kinase (p-JNK), but silencing of IRE1 or p62 and JNK inhibitor SP600125 blocked the LC3II accumulation in Tan I-treated H28 cells. Overall, these findings demonstrate that Tan I exerts antitumor activity through a compromise between apoptosis and p62/SQSTM1-dependent autophagy via activation of JNK and IRE 1 in malignant mesothelioma cells.

  19. Protocatechuic Acid from Alpinia oxyphylla Induces Schwann Cell Migration via ERK1/2, JNK and p38 Activation.

    PubMed

    Ju, Da-Tong; Kuo, Wei-Wen; Ho, Tsung-Jung; Paul, Catherine Reena; Kuo, Chia-Hua; Viswanadha, Vijaya Padma; Lin, Chien-Chung; Chen, Yueh-Sheng; Chang, Yung-Ming; Huang, Chih-Yang

    2015-01-01

    Alpinia oxyphylla MIQ (Alpinate Oxyphyllae Fructus, AOF) is an important traditional Chinese medicinal herb whose fruits is widely used to prepare tonics and is used as an aphrodisiac, anti salivary, anti diuretic and nerve-protective agent. Protocatechuic acid (PCA), a simple phenolic compound was isolated from the kernels of AOF. This study investigated the role of PCA in promoting neural regeneration and the underlying molecular mechanisms. Nerve regeneration is a complex physiological response that takes place after injury. Schwann cells play a crucial role in the endogenous repair of peripheral nerves due to their ability to proliferate and migrate. The role of PCA in Schwann cell migration was determined by assessing the induced migration potential of RSC96 Schwann cells. PCA induced changes in the expression of proteins of three MAPK pathways, as determined using Western blot analysis. In order to determine the roles of MAPK (ERK1/2, JNK, and p38) pathways in PCA-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production, the expression of several MAPK-associated proteins was analyzed after siRNA-mediated inhibition assays. Treatment with PCA-induced ERK1/2, JNK, and p38 phosphorylation that activated the downstream expression of PAs and MMPs. PCA-stimulated ERK1/2, JNK and p38 phosphorylation was attenuated by individual pretreatment with siRNAs or MAPK inhibitors (U0126, SP600125, and SB203580), resulting in the inhibition of migration and the uPA-related signal pathway. Taken together, our data suggest that PCA extract regulate the MAPK (ERK1/2, JNK, and p38)/PA (uPA, tPA)/MMP (MMP2, MMP9) mediated regeneration and migration signaling pathways in Schwann cells. Therefore, PCA plays a major role in Schwann cell migration and the regeneration of damaged peripheral nerve.

  20. JNK signaling mediates EPHA2-dependent tumor cell proliferation, motility, and cancer stem cell-like properties in non-small cell lung cancer

    PubMed Central

    Song, Wenqiang; Ma, Yufang; Wang, Jialiang; Brantley-Sieders, Dana; Chen, Jin

    2014-01-01

    Recent genome-wide analyses in human lung cancer revealed that EPHA2 receptor tyrosine kinase is overexpressed in non-small cell lung cancer (NSCLC), and high levels of EPHA2 correlate with poor clinical outcome. However, the mechanistic basis for EPHA2-mediated tumor promotion in lung cancer remains poorly understood. Here we show that the JNK/c-JUN signaling mediates EPHA2-dependent tumor cell proliferation and motility. A screen of phospho-kinase arrays revealed a decrease in phospho-c-JUN levels in EPHA2 knockdown cells. Knockdown of EPHA2 inhibited p-JNK and p-c-JUN levels in approximately 50% of NSCLC lines tested. Treatment of parental cells with SP600125, a JNK inhibitor, recapitulated defects in EPHA2-deficient tumor cells; whereas constitutively activated JNK mutants were sufficient to rescue phenotypes. Knockdown of EPHA2 also inhibited tumor formation and progression in xenograft animal models in vivo. Furthermore, we investigated the role of EPHA2 in cancer stem-like cells. RNAi-mediated depletion of EPHA2 in multiple NSCLC lines decreased the ALDH positive cancer stem-like population and tumor spheroid formation in suspension. Depletion of EPHA2 in sorted ALDH positive populations markedly inhibited tumorigenicity in nude mice. Furthermore, analysis of a human lung cancer tissue microarray revealed a significant, positive association between EPHA2 and ALDH expression, indicating an important role for EPHA2 in human lung cancer stem-like cells. Collectively, these studies revealed a critical role of JNK signaling in EPHA2-dependent lung cancer cell proliferation and motility and a role for EPHA2 in cancer stem-like cell function, providing evidence for EPHA2 as a potential therapeutic target in NSCLC. PMID:24607842

  1. Synthesis and SAR of piperazine amides as novel c-jun N-terminal kinase (JNK) inhibitors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shin, Youseung; Chen, Weiming; Habel, Jeff

    2009-09-14

    A novel series of c-jun N-terminal kinase (JNK) inhibitors were designed and developed from a high-throughput-screening hit. Through the optimization of the piperazine amide 1, several potent compounds were discovered. The X-ray crystal structure of 4g showed a unique binding mode different from other well known JNK3 inhibitors.

  2. Mechanisms of acetaminophen-induced cell death in primary human hepatocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xie, Yuchao; McGill, Mitchell R.; Dorko, Kenneth

    Acetaminophen (APAP) overdose is the most prevalent cause of drug-induced liver injury in western countries. Numerous studies have been conducted to investigate the mechanisms of injury after APAP overdose in various animal models; however, the importance of these mechanisms for humans remains unclear. Here we investigated APAP hepatotoxicity using freshly isolated primary human hepatocytes (PHH) from either donor livers or liver resections. PHH were exposed to 5 mM, 10 mM or 20 mM APAP over a period of 48 h and multiple parameters were assessed. APAP dose-dependently induced significant hepatocyte necrosis starting from 24 h, which correlated with the clinicalmore » onset of human liver injury after APAP overdose. Interestingly, cellular glutathione was depleted rapidly during the first 3 h. APAP also resulted in early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria) and mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential after 12 h. Furthermore, APAP time-dependently triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria. Both co-treatment and post-treatment (3 h) with the JNK inhibitor SP600125 reduced JNK activation and significantly attenuated cell death at 24 h and 48 h after APAP. The clinical antidote N-acetylcysteine offered almost complete protection even if administered 6 h after APAP and a partial protection when given at 15 h. Conclusion: These data highlight important mechanistic events in APAP toxicity in PHH and indicate a critical role of JNK in the progression of injury after APAP in humans. The JNK pathway may represent a therapeutic target in the clinic. - Highlights: • APAP reproducibly causes cell death in freshly isolated primary human hepatocytes. • APAP induces adduct formation, JNK activation and mitochondrial dysfunction in PHH. • Mitochondrial adducts and JNK translocation are delayed in PHH

  3. WNT5A-JNK regulation of vascular insulin resistance in human obesity.

    PubMed

    Farb, Melissa G; Karki, Shakun; Park, Song-Young; Saggese, Samantha M; Carmine, Brian; Hess, Donald T; Apovian, Caroline; Fetterman, Jessica L; Bretón-Romero, Rosa; Hamburg, Naomi M; Fuster, José J; Zuriaga, María A; Walsh, Kenneth; Gokce, Noyan

    2016-12-01

    Obesity is associated with the development of vascular insulin resistance; however, pathophysiological mechanisms are poorly understood. We sought to investigate the role of WNT5A-JNK in the regulation of insulin-mediated vasodilator responses in human adipose tissue arterioles prone to endothelial dysfunction. In 43 severely obese (BMI 44±11 kg/m 2 ) and five metabolically normal non-obese (BMI 26±2 kg/m 2 ) subjects, we isolated arterioles from subcutaneous and visceral fat during planned surgeries. Using videomicroscopy, we examined insulin-mediated, endothelium-dependent vasodilator responses and characterized adipose tissue gene and protein expression using real-time polymerase chain reaction and Western blot analyses. Immunofluorescence was used to quantify endothelial nitric oxide synthase (eNOS) phosphorylation. Insulin-mediated vasodilation was markedly impaired in visceral compared to subcutaneous vessels from obese subjects (p<0.001), but preserved in non-obese individuals. Visceral adiposity was associated with increased JNK activation and elevated expression of WNT5A and its non-canonical receptors, which correlated negatively with insulin signaling. Pharmacological JNK antagonism with SP600125 markedly improved insulin-mediated vasodilation by sixfold (p<0.001), while endothelial cells exposed to recombinant WNT5A developed insulin resistance and impaired eNOS phosphorylation (p<0.05). We observed profound vascular insulin resistance in the visceral adipose tissue arterioles of obese subjects that was associated with up-regulated WNT5A-JNK signaling and impaired endothelial eNOS activation. Pharmacological JNK antagonism markedly improved vascular endothelial function, and may represent a potential therapeutic target in obesity-related vascular disease. © The Author(s) 2016.

  4. WNT5A-JNK regulation of vascular insulin resistance in human obesity

    PubMed Central

    Farb, Melissa G; Karki, Shakun; Park, Song-Young; Saggese, Samantha M; Carmine, Brian; Hess, Donald T; Apovian, Caroline; Fetterman, Jessica L; Bretón-Romero, Rosa; Hamburg, Naomi M; Fuster, José J; Zuriaga, María A; Walsh, Kenneth; Gokce, Noyan

    2017-01-01

    Obesity is associated with the development of vascular insulin resistance; however, pathophysiological mechanisms are poorly understood. We sought to investigate the role of WNT5A-JNK in the regulation of insulin-mediated vasodilator responses in human adipose tissue arterioles prone to endothelial dysfunction. In 43 severely obese (BMI 44±11 kg/m2) and five metabolically normal non-obese (BMI 26±2 kg/m2) subjects, we isolated arterioles from subcutaneous and visceral fat during planned surgeries. Using videomicroscopy, we examined insulin-mediated, endothelium-dependent vasodilator responses and characterized adipose tissue gene and protein expression using real-time polymerase chain reaction and Western blot analyses. Immunofluorescence was used to quantify endothelial nitric oxide synthase (eNOS) phosphorylation. Insulin-mediated vasodilation was markedly impaired in visceral compared to subcutaneous vessels from obese subjects (p<0.001), but preserved in non-obese individuals. Visceral adiposity was associated with increased JNK activation and elevated expression of WNT5A and its non-canonical receptors, which correlated negatively with insulin signaling. Pharmacological JNK antagonism with SP600125 markedly improved insulin-mediated vasodilation by sixfold (p<0.001), while endothelial cells exposed to recombinant WNT5A developed insulin resistance and impaired eNOS phosphorylation (p<0.05). We observed profound vascular insulin resistance in the visceral adipose tissue arterioles of obese subjects that was associated with up-regulated WNT5A-JNK signaling and impaired endothelial eNOS activation. Pharmacological JNK antagonism markedly improved vascular endothelial function, and may represent a potential therapeutic target in obesity-related vascular disease. PMID:27688298

  5. SP600125 has a remarkable anticancer potential against undifferentiated thyroid cancer through selective action on ROCK and p53 pathways.

    PubMed

    Grassi, Elisa Stellaria; Vezzoli, Valeria; Negri, Irene; Lábadi, Árpád; Fugazzola, Laura; Vitale, Giovanni; Persani, Luca

    2015-11-03

    Thyroid cancer is the most common endocrine malignancy with increasing incidence worldwide.The majority of thyroid cancer cases are well differentiated with favorable outcome. However, undifferentiated thyroid cancers are one of the most lethal human malignancies because of their invasiveness, metastatization and refractoriness even to the most recently developed therapies.In this study we show for the first time a significant hyperactivation of ROCK/HDAC6 pathway in thyroid cancer tissues, and its negative correlation with p53 DNA binding ability.We demonstrate that a small compound, SP600125 (SP), is able to induce cell death selectively in undifferentiated thyroid cancer cell lines by specifically acting on the pathogenic pathways of cancer development. In detail, SP acts on the ROCK/HDAC6 pathway involved in dedifferentiation and invasiveness of undifferentiated human cancers, by restoring its physiological activity level. As main consequence, cancer cell migration is inhibited and, at the same time, cell death is induced through the mitotic catastrophe. Moreover, SP exerts a preferential action on the mutant p53 by increasing its DNA binding ability. In TP53-mutant cells that survive mitotic catastrophe this process results in p21 induction and eventually lead to premature senescence. In conclusion, SP has been proved to be able to simultaneously block cell replication and migration, the two main processes involved in cancer development and dissemination, making it an ideal candidate for developing new drugs against anaplastic thyroid cancer.

  6. Cleome rutidosperma and Euphorbia thymifolia Suppress Inflammatory Response via Upregulation of Phase II Enzymes and Modulation of NF-κB and JNK Activation in LPS-Stimulated BV2 Microglia

    PubMed Central

    Ding, Hsiou-Yu; Wu, Pei-Shan; Wu, Ming-Jiuan

    2016-01-01

    Cleome rutidosperma DC. and Euphorbia thymifolia L. are herbal medicines used in traditional Indian and Chinese medicine to treat various illnesses. Reports document that they have antioxidant and anti-inflammatory activities; nonetheless, the molecular mechanisms involved in their anti-inflammatory actions have not yet been elucidated. The anti-neuroinflammatory activities and underlying mechanisms of ethanol extracts of Cleome rutidosperma (CR) and Euphorbia thymifolia (ET) were studied using lipopolysaccharide (LPS)-stimulated microglial cell line BV2. The morphology changes and production of pro-inflammatory mediators were assayed. Gene expression of inflammatory genes such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, interleukin (IL)-1β, and CC chemokine ligand (CCL)-2, as well as phase II enzymes such as heme oxygenase (HO)-1, the modifier subunit of glutamate cysteine ligase (GCLM) and NAD(P)H quinone dehydrogenase 1 (NQO1), were further investigated using reverse transcription quantitative-PCR (RT-Q-PCR) and Western blotting. The effects of CR and ET on mitogen activated protein kinases (MAPKs) and nuclear factor (NF)-κB signaling pathways were examined using Western blotting and specific inhibitors. CR and ET suppressed BV2 activation, down-regulated iNOS and COX-2 expression and inhibited nitric oxide (NO) overproduction without affecting cell viability. They reduced LPS-mediated tumor necrosis factor (TNF) and IL-6 production, attenuated IL-1β and CCL2 expression, but upregulated HO-1, GCLM and NQO1 expression. They also inhibited p65 NF-κB phosphorylation and modulated Jun-N terminal kinase (JNK) activation in BV2 cells. SP600125, the JNK inhibitor, significantly augmented the anti-IL-6 activity of ET. NF-κB inhibitor, Bay 11-7082, enhanced the anti-IL-6 effects of both CR and ET. Znpp, a competitive inhibitor of HO-1, attenuated the anti-NO effects of CR and ET. Our results show that CR and ET exhibit anti

  7. Cytosolic calcium mediates RIP1/RIP3 complex-dependent necroptosis through JNK activation and mitochondrial ROS production in human colon cancer cells.

    PubMed

    Sun, Wen; Wu, Xiaxia; Gao, Hongwei; Yu, Jie; Zhao, Wenwen; Lu, Jin-Jian; Wang, Jinhua; Du, Guanhua; Chen, Xiuping

    2017-07-01

    Necroptosis is a form of programmed necrosis mediated by signaling complexes with receptor-interacting protein 1 (RIP1) and RIP3 kinases as the main mediators. However, the underlying execution pathways of this phenomenon have yet to be elucidated in detail. In this study, a RIP1/RIP3 complex was formed in 2-methoxy-6-acetyl-7-methyljuglone (MAM)-treated HCT116 and HT29 colon cancer cells. With this formation, mitochondrial reactive oxygen species (ROS) levels increased, mitochondrial depolarization occurred, and ATP concentrations decreased. This process was identified as necroptosis. This finding was confirmed by experiments showing that MAM-induced cell death was attenuated by the pharmacological or genetic blockage of necroptosis signaling, including RIP1 inhibitor necrostatin-1s (Nec-1s) and siRNA-mediated gene silencing of RIP1 and RIP3, but was unaffected by caspase inhibitor z-vad-fmk or necrosis inhibitor 2-(1H-Indol-3-yl)-3-pentylamino-maleimide (IM54). Transmission electron microscopy (TEM) analysis further revealed the ultrastructural features of MAM-induced necroptosis. MAM-induced RIP1/RIP3 complex triggered necroptosis through cytosolic calcium (Ca 2+ ) accumulation and sustained c-Jun N-terminal kinase (JNK) activation. Both calcium chelator BAPTA-AM and JNK inhibitor SP600125 could attenuate necroptotic features, including mitochondrial ROS elevation, mitochondrial depolarization, and ATP depletion. 2-thenoyltrifluoroacetone (TTFA), which is a mitochondrial complex II inhibitor, was found to effectively reverse both MAM induced mitochondrial ROS generation and cell death, indicating the complex II was the ROS-producing site. The essential role of mitochondrial ROS was confirmed by the protective effect of overexpression of manganese superoxide dismutase (MnSOD). MAM-induced necroptosis was independent of TNFα, p53, MLKL, and lysosomal membrane permeabilization. In summary, our study demonstrated that RIP1/RIP3 complex-triggered cytosolic calcium

  8. Biophysical and X-ray crystallographic analysis of Mps1 kinase inhibitor complexes.

    PubMed

    Chu, Matthew L H; Lang, Zhaolei; Chavas, Leonard M G; Neres, João; Fedorova, Olga S; Tabernero, Lydia; Cherry, Mike; Williams, David H; Douglas, Kenneth T; Eyers, Patrick A

    2010-03-02

    The dual-specificity protein kinase monopolar spindle 1 (Mps1) is a central component of the mitotic spindle assembly checkpoint (SAC), a sensing mechanism that prevents anaphase until all chromosomes are bioriented on the metaphase plate. Partial depletion of Mps1 protein levels sensitizes transformed, but not untransformed, human cells to therapeutic doses of the anticancer agent Taxol, making it an attractive novel therapeutic cancer target. We have previously determined the X-ray structure of the catalytic domain of human Mps1 in complex with the anthrapyrazolone kinase inhibitor SP600125. In order to validate distinct inhibitors that target this enzyme and improve our understanding of nucleotide binding site architecture, we now report a biophysical and structural evaluation of the Mps1 catalytic domain in the presence of ATP and the aspecific model kinase inhibitor staurosporine. Collective in silico, enzymatic, and fluorescent screens also identified several new lead quinazoline Mps1 inhibitors, including a low-affinity compound termed Compound 4 (Cpd 4), whose interaction with the Mps1 kinase domain was further characterized by X-ray crystallography. A novel biophysical analysis demonstrated that the intrinsic fluorescence of SP600125 changed markedly upon Mps1 binding, allowing spectrophotometric displacement analysis and determination of dissociation constants for ATP-competitive Mps1 inhibitors. By illuminating the structure of the Mps1 ATP-binding site our results provide novel biophysical insights into Mps1-ligand interactions that will be useful for the development of specific Mps1 inhibitors, including those employing a therapeutically validated quinazoline template.

  9. Bex2 regulates cell proliferation and apoptosis in malignant glioma cells via the c-Jun NH2-terminal kinase pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhou, Xiuping, E-mail: xpzhou@xzmc.edu.cn; Lab of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu; Key Laboratory of Brain Disease Biology, Affiliated Hospital of Xuzhou Medical College, Jiangsu

    Highlights: Black-Right-Pointing-Pointer The expression levels of Bex2 markedly increased in glioma tissues. Black-Right-Pointing-Pointer Bex2 over-expression promoted cell proliferation, while its down-regulation inhibited cell growth. Black-Right-Pointing-Pointer Bex2 down-regulation promoted cell apoptosis via JNK/c-Jun signaling pathway. -- Abstract: The function of Bex2, a member of the Brain Expressed X-linked gene family, in glioma is controversial and its mechanism is largely unknown. We report here that Bex2 regulates cell proliferation and apoptosis in malignant glioma cells via the c-Jun NH2-terminal kinase (JNK) pathway. The expression level of Bex2 is markedly increased in glioma tissues. We observed that Bex2 over-expression promotes cell proliferation, whilemore » down-regulation of Bex2 inhibits cell growth. Furthermore, Bex2 down-regulation promotes cell apoptosis and activates the JNK pathway; these effects were abolished by administration of the JNK specific inhibitor, (SP600125). Thus, Bex2 may be an important player during the development of glioma.« less

  10. Thrombin-induced apoptosis in neurons through activation of c-Jun-N-terminal kinase.

    PubMed

    Bao, Lei; Zu, Jie; He, Qianqian; Zhao, Hui; Zhou, Su; Ye, Xinchun; Yang, Xinxin; Zan, Kun; Zhang, Zuohui; Shi, Hongjuan; Cui, Guiyun

    2017-01-01

    Studies have shown that thrombin activation played a central role in cell injuries associated with intracerebral hemorrhage (ICH). Here, our study investigated the cytotoxicity of thrombin on neurons, and determined the involvement of JNK pathways in thrombin-induced neuronal apoptosis. Primary cultured neurons were treated with different doses of thrombin. Some neurons were given either SP600125 or vehicle. LDH release assay and flow cytometry were used to measure neuronal apoptosis caused by thrombin. The activation of JNK and capases-3 were measured by Western blot. Our results showed large doses of thrombin that increased the LDH release, the level of cleaved caspase-3 and apoptosis rate of neurons. JNK was activated by thrombin in a time-dependent manner. Administration of SP600125 protects neurons from thrombin-induced apoptosis. These data indicate that the activation of JNK is crucial for thrombin-induced neuronal apoptosis, and inhibition of JNK may be a potential therapeutic target for ICH.

  11. Aldosterone induces clonal β-cell failure through glucocorticoid receptor

    PubMed Central

    Chen, Fang; Liu, Jia; Wang, Yanyang; Wu, Tijun; Shan, Wei; Zhu, Yunxia; Han, Xiao

    2015-01-01

    Aldosterone excess causes insulin resistance in peripheral tissues and directly impairs the function of clonal β-cell. The aim of this study was to investigate the molecular mechanisms involved in the aldosterone-induced impairment of clonal β-cells. As expected, aldosterone induced apoptosis and β-cell dysfunction, including impairment of insulin synthesis and secretion, which were reversed by Glucocorticoid receptor (GR) antagonists or GR-specific siRNA. However, mineralocorticoid receptor (MR) antagonists or MR-specific siRNA had no effect on impairment of clonal β-cells induced by aldosterone. Besides, aldosterone significantly decreased expression and activity of MafA, while activated JNK and p38 MAPK in a GR-dependent manner. In addition, JNK inhibitors (SP600125) and/or p38 inhibitors (SB203580) could abolish the effect of aldosterone on MafA expression and activity. Importantly, overexpression of JNK1 or p38 reversed the protective effect of a GR antagonist on the decrease of MafA expression and activity. Furthermore, aldosterone inhibits MafA expression at the transcriptional and post-transcriptional level through activation of JNK and p38, respectively. Consequently, overexpression of MafA increased synthesis and secretion of insulin, and decreased apoptosis in clonal β-cells exposed to aldosterone. These findings identified aldosterone as an inducer of clonal β-cell failure that operates through the GR-MAPK-MafA signaling pathway. PMID:26287126

  12. Blockade of the spinal BDNF-activated JNK pathway prevents the development of antiretroviral-induced neuropathic pain.

    PubMed

    Sanna, Maria Domenica; Ghelardini, Carla; Galeotti, Nicoletta

    2016-06-01

    Although antiretroviral agents have been used successfully in suppressing viral production, they have also been associated with a number of side effects. The antiretroviral toxic neuropathy induces debilitating and extremely difficult to treat pain syndromes that often lead to discontinuation of antiretroviral therapy. Due to the critical need for the identification of novel therapeutic targets to improve antiretroviral neuropathic pain management, we investigated the role of the JNK signalling pathway in the mechanism of antiretroviral painful neuropathy. Mice were exposed to zalcitabine (2',3'-dideoxycytidine, ddC) and stavudine (2',3'-didehydro-3'-deoxythymidine, d4T) that induced a persistent mechanical allodynia and a transient cold allodynia. Treatment with the JNK blocker SP600125 before antiretroviral administration abolished mechanical hypersensitivity with no effect on thermal response. A robust spinal JNK overphosphorylation was observed on post-injection day 1 and 3, along with a JNK-dependent increase in p-c-Jun and ATF3 protein levels. Co-immunoprecipitation experiments showed the presence of a heterodimeric complex between ATF3 and c-Jun indicating that these transcription factors can act together to regulate transcription through heterodimerization. A rise in BDNF and caspase-3 protein levels was detected on day 1 and BDNF sequestration prevented both caspase-3 and p-JNK increase. These data suggest that BDNF plays a role in the early stages of ddC-induced allodynia by promoting apoptotic events and the activation of a hypernociceptive JNK-mediated pathway. We illustrated the activation of a BDNF-mediated JNK pathway involved in the early events responsible for the promotion of neuropathic pain, leading to a better knowledge of the mechanisms involved in the antiretroviral neuropathy. JNK blockade prevents antiretroviral-induced pain hypersensitivity. This may represent a potential prophylactic treatment of neuropathic pain to improve antiretroviral

  13. Dexamethasone inhibits IL-12p40 production in lipopolysaccharide-stimulated human monocytic cells by down-regulating the activity of c-Jun N-terminal kinase, the activation protein-1, and NF-kappa B transcription factors.

    PubMed

    Ma, Wei; Gee, Katrina; Lim, Wilfred; Chambers, Kelly; Angel, Jonathan B; Kozlowski, Maya; Kumar, Ashok

    2004-01-01

    IL-12 plays a critical role in the development of cell-mediated immune responses and in the pathogenesis of inflammatory and autoimmune disorders. Dexamethasone (DXM), an anti-inflammatory glucocorticoid, has been shown to inhibit IL-12p40 production in LPS-stimulated monocytic cells. In this study, we investigated the molecular mechanism by which DXM inhibits IL-12p40 production by studying the role of the mitogen-activated protein kinases (MAPKs), and the key transcription factors involved in human IL-12p40 production in LPS-stimulated monocytic cells. A role for c-Jun N-terminal kinase (JNK) MAPK in LPS-induced IL-12p40 regulation in a promonocytic THP-1/CD14 cell line was demonstrated by using specific inhibitors of JNK activation, SP600125 and a dominant-negative stress-activated protein/extracellular signal-regulated kinase kinase-1 mutant. To identify transcription factors regulating IL-12p40 gene transcription, extensive deletion analyses of the IL-12p40 promoter was performed. The results revealed the involvement of a sequence encompassing the AP-1-binding site, in addition to that of NF-kappaB. The role of AP-1 in IL-12p40 transcription was confirmed by using antisense c-fos and c-jun oligonucleotides. Studies conducted to understand the regulation of AP-1 and NF-kappaB activation by JNK MAPK revealed that both DXM and SP600125 inhibited IL-12p40 gene transcription by inhibiting the activation of AP-1 and NF-kappaB transcription factors as revealed by luciferase reporter and gel mobility shift assays. Taken together, our results suggest that DXM may inhibit IL-12p40 production in LPS-stimulated human monocytic cells by down-regulating the activation of JNK MAPK, the AP-1, and NF-kappaB transcription factors.

  14. BRAF inhibitors suppress apoptosis through off-target inhibition of JNK signaling

    PubMed Central

    Vin, Harina; Ojeda, Sandra S; Ching, Grace; Leung, Marco L; Chitsazzadeh, Vida; Dwyer, David W; Adelmann, Charles H; Restrepo, Monica; Richards, Kristen N; Stewart, Larissa R; Du, Lili; Ferguson, Scarlett B; Chakravarti, Deepavali; Ehrenreiter, Karin; Baccarini, Manuela; Ruggieri, Rosamaria; Curry, Jonathan L; Kim, Kevin B; Ciurea, Ana M; Duvic, Madeleine; Prieto, Victor G; Ullrich, Stephen E; Dalby, Kevin N; Flores, Elsa R; Tsai, Kenneth Y

    2013-01-01

    Vemurafenib and dabrafenib selectively inhibit the v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) kinase, resulting in high response rates and increased survival in melanoma. Approximately 22% of individuals treated with vemurafenib develop cutaneous squamous cell carcinoma (cSCC) during therapy. The prevailing explanation for this is drug-induced paradoxical ERK activation, resulting in hyperproliferation. Here we show an unexpected and novel effect of vemurafenib/PLX4720 in suppressing apoptosis through the inhibition of multiple off-target kinases upstream of c-Jun N-terminal kinase (JNK), principally ZAK. JNK signaling is suppressed in multiple contexts, including in cSCC of vemurafenib-treated patients, as well as in mice. Expression of a mutant ZAK that cannot be inhibited reverses the suppression of JNK activation and apoptosis. Our results implicate suppression of JNK-dependent apoptosis as a significant, independent mechanism that cooperates with paradoxical ERK activation to induce cSCC, suggesting broad implications for understanding toxicities associated with BRAF inhibitors and for their use in combination therapies. DOI: http://dx.doi.org/10.7554/eLife.00969.001 PMID:24192036

  15. Apoptosis Signal-Regulating Kinase 1 Is Involved in Brain-Derived Neurotrophic Factor (BDNF)-Enhanced Cell Motility and Matrix Metalloproteinase 1 Expression in Human Chondrosarcoma Cells

    PubMed Central

    Lin, Chih-Yang; Chang, Sunny Li-Yun; Fong, Yi-Chin; Hsu, Chin-Jung; Tang, Chih-Hsin

    2013-01-01

    Chondrosarcoma is the primary malignancy of bone that is characterized by a potent capacity to invade locally and cause distant metastasis, and is therefore associated with poor prognoses. Chondrosarcoma further shows a predilection for metastasis to the lungs. The brain-derived neurotrophic factor (BDNF) is a small molecule in the neurotrophin family of growth factors that is associated with the disease status and outcome of cancers. However, the effect of BDNF on cell motility in human chondrosarcoma cells is mostly unknown. Here, we found that human chondrosarcoma cell lines had significantly higher cell motility and BDNF expression compared to normal chondrocytes. We also found that BDNF increased cell motility and expression of matrix metalloproteinase-1 (MMP-1) in human chondrosarcoma cells. BDNF-mediated cell motility and MMP-1 up-regulation were attenuated by Trk inhibitor (K252a), ASK1 inhibitor (thioredoxin), JNK inhibitor (SP600125), and p38 inhibitor (SB203580). Furthermore, BDNF also promoted Sp1 activation. Our results indicate that BDNF enhances the migration and invasion activity of chondrosarcoma cells by increasing MMP-1 expression through a signal transduction pathway that involves the TrkB receptor, ASK1, JNK/p38, and Sp1. BDNF thus represents a promising new target for treating chondrosarcoma metastasis. PMID:23892595

  16. JNK1 induces hedgehog signaling from stellate cells to accelerate liver regeneration in mice.

    PubMed

    Langiewicz, Magda; Graf, Rolf; Humar, Bostjan; Clavien, Pierre A

    2018-04-28

    To improve outcomes of two-staged hepatectomies for large/multiple liver tumors, portal vein ligation (PVL) has been combined with parenchymal transection (associating liver partition and portal vein ligation for staged hepatectomy [coined ALPPS]) to greatly accelerate liver regeneration. In a novel ALPPS mouse model, we have reported paracrine Indian hedgehog (IHH) signaling from stellate cells as an early contributor to augmented regeneration. Here, we sought to identify upstream regulators of IHH. ALPPS in mice was compared against PVL and additional control surgeries. Potential IHH regulators were identified through in silico mining of transcriptomic data. c-Jun N-terminal kinase (JNK1 [Mapk8]) activity was reduced through SP600125 to evaluate its effects on IHH signaling. Recombinant IHH was injected after JNK1 diminution to substantiate their relationship during accelerated liver regeneration. Transcriptomic analysis linked Ihh to Mapk8. JNK1 upregulation after ALPPS was validated and preceded the IHH peak. On immunofluorescence, JNK1 and IHH co-localized in alpha-smooth muscle actin-positive non-parenchymal cells. Inhibition of JNK1 prior to ALPPS surgery reduced liver weight gain to PVL levels and was accompanied by downregulation of hepatocellular proliferation and the IHH-GLI1-CCND1 axis. In JNK1-inhibited mice, recombinant IHH restored ALPPS-like acceleration of regeneration and re-elevated JNK1 activity, suggesting the presence of a positive IHH-JNK1 feedback loop. JNK1-mediated induction of IHH paracrine signaling from hepatic stellate cells is essential for accelerated regeneration of parenchymal mass. The JNK1-IHH axis is a mechanism unique to ALPPS surgery and may point to therapeutic alternatives for patients with insufficient regenerative capacity. Associating liver partition and portal vein ligation for staged hepatectomy (so called ALPPS), is a new two-staged approach to hepatectomy, which induces an unprecedented acceleration of liver

  17. Dual p38/JNK Mitogen Activated Protein Kinase Inhibitors Prevent Ozone-Induced Airway Hyperreactivity in Guinea Pigs

    PubMed Central

    Verhein, Kirsten C.; Salituro, Francesco G.; Ledeboer, Mark W.; Fryer, Allison D.; Jacoby, David B.

    2013-01-01

    Ozone exposure causes airway hyperreactivity and increases hospitalizations resulting from pulmonary complications. Ozone reacts with the epithelial lining fluid and airway epithelium to produce reactive oxygen species and lipid peroxidation products, which then activate cell signaling pathways, including the mitogen activated protein kinase (MAPK) pathway. Both p38 and c-Jun NH2 terminal kinase (JNK) are MAPK family members that are activated by cellular stress and inflammation. To test the contribution of both p38 and JNK MAPK to ozone-induced airway hyperreactivity, guinea pigs were pretreated with dual p38 and JNK MAPK inhibitors (30 mg/kg, ip) 60 minutes before exposure to 2 ppm ozone or filtered air for 4 hours. One day later airway reactivity was measured in anesthetized animals. Ozone caused airway hyperreactivity one day post-exposure, and blocking p38 and JNK MAPK completely prevented ozone-induced airway hyperreactivity. Blocking p38 and JNK MAPK also suppressed parasympathetic nerve activity in air exposed animals, suggesting p38 and JNK MAPK contribute to acetylcholine release by airway parasympathetic nerves. Ozone inhibited neuronal M2 muscarinic receptors and blocking both p38 and JNK prevented M2 receptor dysfunction. Neutrophil influx into bronchoalveolar lavage was not affected by MAPK inhibitors. Thus p38 and JNK MAPK mediate ozone-induced airway hyperreactivity through multiple mechanisms including prevention of neuronal M2 receptor dysfunction. PMID:24058677

  18. Taurine zinc solid dispersions enhance bile-incubated L02 cell viability and improve liver function by inhibiting ERK2 and JNK phosphorylation during cholestasis.

    PubMed

    Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lai, Xiaofang; Xu, Donghui

    2016-07-29

    Dietary intakes of taurine and zinc are associated with decreased risk of liver disease. In this study, solid dispersions (SDs) of a taurine zinc complex on hepatic injury were examined in vitro using the immortalized human hepatocyte cell line L02 and in a rat model of bile duct ligation. Sham-operated and bile duct ligated Sprague-Dawley rats were treated with the vehicle alone or taurine zinc (40, 80, 160mg/kg) for 17days. Bile duct ligation significantly increased blood lipid levels, and promoted hepatocyte apoptosis, inflammation and compensatory biliary proliferation. In vitro, incubation with bile significantly reduced L02 cell viability; this effect was significantly attenuated by pretreatment with SP600125 (a JNK inhibitor) and enhanced when co-incubated with taurine zinc SDs. In vivo, administration of taurine zinc SDs decreased serum alanine aminotransferase and aspartate aminotransferase activities in a dose-dependent manner and attenuated the increases in serum total bilirubin, total cholesterol and low density lipoprotein cholesterol levels after bile duct ligation. Additionally, taurine zinc SDs downregulated the expression of interleukin-1β and inhibited the phosphorylation of Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase2 (ERK2) in the liver after bile duct ligation. Moreover, taurine zinc SDs had more potent blood lipid regulatory and anti-apoptotic effects than the physical mixture of taurine and zinc acetate. Therefore, we speculate that taurine zinc SDs protect liver function at least in part via a mechanism linked to reduce phosphorylation of JNK and ERK2, which suppresses inflammation, apoptosis and cholangiocyte proliferation during cholestasis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. p38 Mitogen-Activated Protein Kinase in Metastasis Associated with Transforming Growth Factor Beta

    DTIC Science & Technology

    2006-06-01

    Functional Analysis of cells • Expression of HA-tagged TβRI • Signaling (p-Smad2, p- HSP27 , p-p38) • Transcription (SBE-Lux, 3TP-Lux) • Proliferation...when they also affected lls expressing DN-p38alpha phosphorylation of HSP27 was effectively blocked (data not shown). However, cells e studies show...231-ALK5-T204D cells treated with kinase inhibitors U0126, SB202190, SP600125 (JNK). (B) Immunoblot of phospho-Smad2/3, phospho- HSP27 , and alpha

  20. Imatinib mesylate induction of ROS-dependent apoptosis in melanoma B16F0 cells.

    PubMed

    Chang, Shao-Ping; Shen, Shing-Chuan; Lee, Woan-Rouh; Yang, Ling-Ling; Chen, Yen-Chou

    2011-06-01

    Imatinib mesylate (STI571), a protein tyrosine kinase inhibitor, was shown to reduce the viability of several cancer cell lines via apoptosis induction; however, the role of reactive oxygen species (ROS) in STI571-induced melanoma cell apoptosis is still undefined. In this study, we investigated the contribution of ROS to STI571-induced apoptosis in melanoma B16F0 cells, and the apoptotic mechanism elicited by STI571 was illustrated. Using an in vitro cell culture system, the effects of STI571 on ROS production, cell cycle progression, caspase activation, and mitochondrial functions were examined via Western blotting, a flow cytometric analysis, an enzyme activity assay, and a DNA integrity assay. In pharmacological studies, the ROS scavenger, N-acetyl cysteine (NAC), the NADPH oxidase inhibitor, dipheylene iodide (DPI), and mitogen-activated protein kinase (MAPK) inhibitors (PD98059, SP600125, and SB203580) were applied to investigate the mechanism. STI571 reduced the viability of melanoma cells B16F0, but not human skin fibroblasts WS1, via apoptosis induction. Besides, apoptosis induced by STI571 was inhibited by the addition of NAC and DPI, and an increase in the intracellular peroxide level by STI571 was identified in melanoma B16F0 cells. Activation of caspases 3 and 9 enzyme activities accompanied by disrupting the mitochondria membrane potential in according with stimulating JNK and p38 protein phosphorylation was identified in STI571-treated B16F0 cells. STI571-mediated a ROS-dependent apoptosis potentiated by JNK inhibitor SP600125 was first identified in melanoma B16F0 cells. Our results support the idea that ROS-dependent apoptosis in STI571-treated melanoma cells B16F0. The combination of a JNK inhibitor with STI571 for treating melanomas is suggested for further in vivo studies. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Upregulation of contractile endothelin type B receptors by lipid-soluble cigarette smoking particles in rat cerebral arteries via activation of MAPK

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sandhu, Hardip, E-mail: sandhu.hardip@gmail.co; Xu, Cang Bao; Edvinsson, Lars

    2010-11-15

    Cigarette smoke exposure increases the risk of stroke. However, the underlying molecular mechanisms are poorly understood. Endothelin system plays key roles in the pathogenesis of stroke. The present study was designed to examine if lipid-soluble (dimethyl sulfoxide-soluble) cigarette smoke particles (DSP) induces upregulation of contractile endothelin type B (ET{sub B}) receptors in rat cerebral arteries and if activation of mitogen activated protein kinase (MAPK) and nuclear factor-kappaB (NF-{kappa}B) mediate the upregulation of contractile endothelin receptors in the cerebral arteries. Rat middle cerebral arteries were isolated and organ cultured in serum free medium for 24 h in the presence of DSPmore » with or without specific inhibitors: MEK specific (U0126), p38 specific (SB202190), JNK specific (SP600125), NF-{kappa}B specific (BMS-345541) or (IMD-0354), transcription inhibitor (actinomycin D), or translation blocker (cycloheximide). Contractile responses to the ET{sub B} receptor agonist sarafotoxin 6c were investigated by a sensitive myograph. The expression of the ET{sub B} receptors were studied at mRNA and protein levels using quantitative real time PCR and immunohistochemistry, respectively. Results show that organ culture per se induced transcriptional upregulation of contractile ET{sub B} receptors in the cerebral vascular smooth muscle cells. This upregulation was further increased at the translational level by addition of DSP to the organ culture, but this increase was not seen by addition of nicotine or water-soluble cigarette smoke particles to the organ culture. The increased upregulation of contractile ET{sub B} receptors by DSP was abrogated by U0126, SP600125, actinomycin D, and cycloheximide, suggesting that the underlying molecular mechanisms involved in this process include activation of MEK and JNK MAPK-mediated transcription and translation of new contractile ET{sub B} receptors. Thus, the MAPK-mediated upregulation of contractile ET

  2. Pirfenidone Induces G1 Arrest in Human Tenon's Fibroblasts In Vitro Involving AKT and MAPK Signaling Pathways.

    PubMed

    Guo, Xiujuan; Yang, Yangfan; Liu, Liling; Liu, Xiaoan; Xu, Jiangang; Wu, Kaili; Yu, Minbin

    2017-06-01

    To investigate the underlying mechanism by which pirfenidone blocks the transition from the G1 to S phase in primary human Tenon's fibroblasts. Primary human Tenon's fibroblasts were characterized by immunocytofluorescence staining with vimentin, fibroblast surface protein, and cytokeratin. After treating Tenon's fibroblasts with pirfenidone under proliferation conditions (10% fetal bovine serum), cell proliferation was measured using a WST-1 assay. Progression through the cell cycle was analyzed by flow cytometry. The expression of CDK2, CDK6, cyclinD1, cyclinD3, and cyclinE and the phosphorylation of AKT, ERK1/2/MAPK, JNK/MAPK, and p38 MAPK were estimated using western blot analysis. Under proliferative conditions, pirfenidone inhibited Tenon's fibroblasts proliferation and arrested the cell cycle at the G1 phase; decreased the phosphorylation of AKT, GSK3β, ERK1/2/MAPK, and JNK/MAPK; increased the phosphorylation of p38 MAPK; and inhibited CDK2, CDK6, cyclin D1, cyclin D3, and cyclin E in a dose-dependent manner. Inhibitors of AKT (LY294002), ERK1/2 (U0126), and JNK (SP600125) arrested the G1/S transition, similar to the effect of pirfenidone. The p38 inhibitor (SB202190) decreased the G1-blocking effect of pirfenidone. The expression of CDK2, CDK6, cyclin D1, and cyclin D3 were inhibited by LY294002, U0126, and SP600125. SB202190 attenuated the pirfenidone-induced reduction of CDK2, CDK6, cyclin D1, cyclin D3, and cyclin E. Pirfenidone inhibited HTFs proliferation and induced G1 arrest by downregulating CDKs and cyclins involving the AKT/GSK3β and MAPK signaling pathways.

  3. Gallic Acid Induces a Reactive Oxygen Species-Provoked c-Jun NH2-Terminal Kinase-Dependent Apoptosis in Lung Fibroblasts

    PubMed Central

    Chen, Chiu-Yuan; Chen, Kun-Chieh; Yang, Tsung-Ying; Liu, Hsiang-Chun; Hsu, Shih-Lan

    2013-01-01

    Idiopathic pulmonary fibrosis is a chronic lung disorder characterized by fibroblasts proliferation and extracellular matrix accumulation. Induction of fibroblast apoptosis therefore plays a crucial role in the resolution of this disease. Gallic acid (3,4,5-trihydroxybenzoic acid), a common botanic phenolic compound, has been reported to induce apoptosis in tumor cell lines and renal fibroblasts. The present study was undertaken to examine the role of mitogen-activated protein kinases (MAPKs) in lung fibroblasts apoptosis induced by gallic acid. We found that treatment with gallic acid resulted in activation of c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and protein kinase B (PKB, Akt), but not p38MAPK, in mouse lung fibroblasts. Inhibition of JNK using pharmacologic inhibitor (SP600125) and genetic knockdown (JNK specific siRNA) significantly inhibited p53 accumulation, reduced PUMA and Fas expression, and abolished apoptosis induced by gallic acid. Moreover, treatment with antioxidants (vitamin C, N-acetyl cysteine, and catalase) effectively diminished gallic acid-induced hydrogen peroxide production, JNK and p53 activation, and cell death. These observations imply that gallic acid-mediated hydrogen peroxide formation acts as an initiator of JNK signaling pathways, leading to p53 activation and apoptosis in mouse lung fibroblasts. PMID:23533505

  4. A Phenotypic Screen in Zebrafish Identifies a Novel Small-Molecule Inducer of Ectopic Tail Formation Suggestive of Alterations in Non-Canonical Wnt/PCP Signaling

    PubMed Central

    Gebruers, Evelien; Cordero-Maldonado, María Lorena; Gray, Alexander I.; Clements, Carol; Harvey, Alan L.; Edrada-Ebel, Ruangelie; de Witte, Peter A. M.; Crawford, Alexander D.; Esguerra, Camila V.

    2013-01-01

    Zebrafish have recently emerged as an attractive model for the in vivo bioassay-guided isolation and characterization of pharmacologically active small molecules of natural origin. We carried out a zebrafish-based phenotypic screen of over 3000 plant-derived secondary metabolite extracts with the goal of identifying novel small-molecule modulators of the BMP and Wnt signaling pathways. One of the bioactive plant extracts identified in this screen – Jasminum gilgianum, an Oleaceae species native to Papua New Guinea – induced ectopic tails during zebrafish embryonic development. As ectopic tail formation occurs when BMP or non-canonical Wnt signaling is inhibited during the tail protrusion process, we suspected a constituent of this extract to act as a modulator of these pathways. A bioassay-guided isolation was carried out on the basis of this zebrafish phenotype, identifying para-coumaric acid methyl ester (pCAME) as the active compound. We then performed an in-depth phenotypic analysis of pCAME-treated zebrafish embryos, including a tissue-specific marker analysis of the secondary tails. We found pCAME to synergize with the BMP-inhibitors dorsomorphin and LDN-193189 in inducing ectopic tails, and causing convergence-extension defects in compound-treated embryos. These results indicate that pCAME may interfere with non-canonical Wnt signaling. Inhibition of Jnk, a downstream target of Wnt/PCP signaling (via morpholino antisense knockdown and pharmacological inhibition with the kinase inhibitor SP600125) phenocopied pCAME-treated embryos. However, immunoblotting experiments revealed pCAME to not directly inhibit Jnk-mediated phosphorylation of c-Jun, suggesting additional targets of SP600125, and/or other pathways, as possibly being involved in the ectopic tail formation activity of pCAME. Further investigation of pCAME’s mechanism of action will help determine this compound’s pharmacological utility. PMID:24349481

  5. Nobiletin inhibits human osteosarcoma cells metastasis by blocking ERK and JNK-mediated MMPs expression

    PubMed Central

    Cheng, Hsin-Lin; Hsieh, Ming-Ju; Yang, Jia-Sin; Lin, Chiao-Wen; Lue, Ko-Haung; Lu, Ko-Hsiu; Yang, Shun-Fa

    2016-01-01

    Nobiletin, a polymethoxyflavone, has a few pharmacological activities, including anti-inflammation and anti-cancer effects. However, its effect on human osteosarcoma progression remains uninvestigated. Therefore, we examined the effectiveness of nobiletin against cellular metastasis of human osteosarcoma and the underlying mechanisms. Nobiletin, up to 100 μM without cytotoxicity, significantly decreased motility, migration and invasion as well as enzymatic activities, protein levels and mRNA expressions of matrix metalloproteinase (MMP)-2 and MMP-9 in U2OS and HOS cells. In addition to inhibition of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), the inhibitory effect of nobiletin on the DNA-binding activity of the transcription factor nuclear factor-kappa B (NF-κB), cAMP response element-binding protein (CREB), and specificity protein 1 (SP-1) in U2OS and HOS cells. Co-treatment with ERK and JNK inhibitors and nobiletin further reduced U2OS cells migration and invasion. These results indicated that nobiletin inhibits human osteosarcoma U2OS and HOS cells motility, migration and invasion by down-regulating MMP-2 and MMP-9 expressions via ERK and JNK pathways and through the inactivation of downstream NF-κB, CREB, and SP-1. Nobiletin has the potential to serve as an anti-metastatic agent for treating osteosarcoma. PMID:27144433

  6. Periostin promotes migration and osteogenic differentiation of human periodontal ligament mesenchymal stem cells via the Jun amino-terminal kinases (JNK) pathway under inflammatory conditions.

    PubMed

    Tang, Yi; Liu, Lin; Wang, Pei; Chen, Donglei; Wu, Ziqiang; Tang, Chunbo

    2017-12-01

    Mesenchymal stem cell (MSC)-mediated periodontal tissue regeneration is considered to be a promising method for periodontitis treatment. The molecular mechanism of functional regulation by MSCs remains unclear, thus limiting their application. Our previous study discovered that Periostin (POSTN) promoted the migration and osteogenic differentiation of periodontal ligament mesenchymal stem cells (PDLSCs), but it is still unclear whether POSTN is able to restore the regenerative potential of PDLSCs under inflammatory conditions. In this study, we investigated the effect of POSTN on PDLSCs under inflammatory conditions and its mechanism. PDLSCs were isolated from periodontal ligament tissue. TNF-α was used at 10 ng/mL to mimic inflammatory conditions. Lentivirus POSTN shRNA was used to knock down POSTN. Recombinant human POSTN (rhPOSTN) was used to stimulate PDLSCs. A scratch assay was used to analyse cell migration. Alkaline phosphatase (ALP) activity, Alizarin Red staining and expression of osteogenesis-related genes were used to investigate the osteogenic differentiation potential. Western blot analysis was used to detect the mitogen-activated protein kinases (MAPK) and AKT signalling pathways. After a 10 ng/mL TNF-α treatment, knockdown of POSTN impeded scratch closure, inhibited ALP activity and mineralization in vitro, and decreased expression of RUNX2, OSX, OPN and OCN in PDLSCs, while 75 ng/mL rhPOSTN significantly accelerated scratch closure, enhanced ALP activity and mineralization in vitro, and increased expression of RUNX2, OSX, OPN and OCN. In addition, knockdown of POSTN inhibited expression of phosphorylated c-Jun N-terminal kinase (p-JNK), while 75 ng/mL rhPOSTN increased expression of p-JNK in PDLSCs with TNF-α treatment. Furthermore, inhibition of JNK by its inhibitor SP600125 dramatically blocked POSTN-enhanced scratch closure, ALP activity and mineralization in PDLSCs. Our results revealed that POSTN might promote the migration and

  7. Induction of apoptosis by thrombin in the cultured neurons of dorsal motor nucleus of the vagus.

    PubMed

    Wu, X; Zhang, W; Li, J-Y; Chai, B-X; Peng, J; Wang, H; Mulholland, M W

    2011-03-01

    A previous study demonstrated the presence of protease-activated receptor (PAR) 1 and 2 in the dorsal motor nucleus of vagus (DMV). The aim of this study is to characterize the effect of thrombin on the apoptosis of DMV neurons. The dorsal motor nucleus of vagus neurons were isolated from neonatal rat brainstems using micro-dissection and enzymatic digestion and cultured. Apoptosis of DMV neurons were examined in cultured neurons. Apoptotic neuron was examined by TUNEL and ELISA. Data were analyzed using anova and Student's t-test. Exposure of cultured DMV neurons to thrombin (0.1 to 10 U mL(-1)) for 24 h significantly increased apoptosis. Pretreatment of DMV neurons with hirudin attenuated the apoptotic effect of thrombin. Similar induction of apoptosis was observed for the PAR1 receptor agonist SFLLR, but not for the PAR3 agonist TFRGAP, nor for the PAR4 agonist YAPGKF. Protease-activated receptors 1 receptor antagonist Mpr(Cha) abolished the apoptotic effect of thrombin, while YPGKF, a specific antagonist for PAR4, demonstrated no effect. After administration of thrombin, phosphorylation of JNK and P38 occurred as early as 15 min, and remained elevated for up to 45 min. Pretreatment of DMV neurons with SP600125, a specific inhibitor for JNK, or SB203580, a specific inhibitor for P38, significantly inhibited apoptosis induced by thrombin. Thrombin induces apoptosis in DMV neurons through a mechanism involving the JNK and P38 signaling pathways. © 2010 Blackwell Publishing Ltd.

  8. Samsoeum, a traditional herbal medicine, elicits apoptotic and autophagic cell death by inhibiting Akt/mTOR and activating the JNK pathway in cancer cells

    PubMed Central

    2013-01-01

    Background Samsoeum (SSE), a traditional herbal formula, has been widely used to treat cough, fever, congestion, and emesis for centuries. Recent studies have demonstrated that SSE retains potent pharmacological efficiency in anti-allergic and anti-inflammatory reactions. However, the anti-cancer activity of SSE and its underlying mechanisms have not been studied. Thus, the present study was designed to determine the effect of SSE on cell death and elucidate its detailed mechanism. Methods Following SSE treatment, cell growth and cell death were measured using an MTT assay and trypan blue exclusion assay, respectively. Cell cycle arrest and YO-PRO-1 uptake were assayed using flow cytometry, and LC3 redistribution was observed using confocal microscope. The mechanisms of anti-cancer effect of SSE were investigated through western blot analysis. Results We initially found that SSE caused dose- and time-dependent cell death in cancer cells but not in normal primary hepatocytes. In addition, during early SSE treatment (6–12 h), cells were arrested in G2/M phase concomitant with up-regulation of p21 and p27 and down-regulation of cyclin D1 and cyclin B1, followed by an increase in apoptotic YO-PRO-1 (+) cells. SSE also induced autophagy via up-regulation of Beclin-1 expression, conversion of microtubule-associated protein light chain 3 (LC3) I to LC3-II, and re-distribution of LC3, indicating autophagosome formation. Moreover, the level of B-cell lymphoma 2 (Bcl-2), which is critical for cross-talk between apoptosis and autophagy, was significantly reduced in SSE-treated cells. Phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) was increased, followed by suppression of the protein kinase B/mammalian target of rapamycin (Akt/mTOR) pathway, and phosphorylation of mitogen-activated protein kinases (MAPKs) in response to SSE treatment. In particular, among MAPKs inhibitors, only the c-Jun N-terminal kinase (JNK)-specific inhibitor SP600125 nearly

  9. House dust mite induces expression of intercellular adhesion molecule-1 in EoL-1 human eosinophilic leukemic cells.

    PubMed

    Kwon, Byoung Chul; Sohn, Myung Hyun; Kim, Kyung Won; Kim, Eun Soo; Kim, Kyu-Earn; Shin, Myeong Heon

    2007-10-01

    The house dust mite (HDM) is considered to be the most common indoor allergen associated with bronchial asthma. In this study, we investigated whether crude extract of the HDM Dermatophagoides farinae could activate human eosinophilic leukemic cells (EoL-1) to induce upregulation of cell-surface adhesion molecules. When EoL-1 cells were incubated with D. farinae extract, expression of intercellular adhesion molecule-1 (ICAM-1) significantly increased on the cell surfaces compared to cells incubated with medium alone. In contrast, surface expression of CD11b and CD49d in EoL-1 cells was not affected by D. farinae extract. In addition, pretreatment of cells with NF-kappaB inhibitor (MG-132) or JNK inhibitor (SP600125) significantly inhibited ICAM-1 expression promoted by HDM extract. However, neither p38 MAP kinase inhibitor nor MEK inhibitor prevented HDM-induced ICAM-1 expression in EoL-1 cells. These results suggest that crude extract of D. farinae induces ICAM-1 expression in EoL-1 cells through signaling pathways involving both NF-kappaB and JNK.

  10. House Dust Mite Induces Expression of Intercellular Adhesion Molecule-1 in EoL-1 Human Eosinophilic Leukemic Cells

    PubMed Central

    Kwon, Byoung Chul; Sohn, Myung Hyun; Kim, Kyung Won; Kim, Eun Soo; Kim, Kyu-Earn

    2007-01-01

    The house dust mite (HDM) is considered to be the most common indoor allergen associated with bronchial asthma. In this study, we investigated whether crude extract of the HDM Dermatophagoides farinae could activate human eosinophilic leukemic cells (EoL-1) to induce upregulation of cell-surface adhesion molecules. When EoL-1 cells were incubated with D. farinae extract, expression of intercellular adhesion molecule-1 (ICAM-1) significantly increased on the cell surfaces compared to cells incubated with medium alone. In contrast, surface expression of CD11b and CD49d in EoL-1 cells was not affected by D. farinae extract. In addition, pretreatment of cells with NF-κB inhibitor (MG-132) or JNK inhibitor (SP600125) significantly inhibited ICAM-1 expression promoted by HDM extract. However, neither p38 MAP kinase inhibitor nor MEK inhibitor prevented HDM-induced ICAM-1 expression in EoL-1 cells. These results suggest that crude extract of D. farinae induces ICAM-1 expression in EoL-1 cells through signaling pathways involving both NF-κB and JNK. PMID:17982228

  11. Efavirenz and 8-hydroxyefavirenz induce cell death via a JNK- and BimEL-dependent mechanism in primary human hepatocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bumpus, Namandje N., E-mail: nbumpus1@jhmi.edu

    Chronic use of efavirenz (EFV) has been linked to incidences of hepatotoxicity in patients receiving EFV to treat HIV-1. While recent studies have demonstrated that EFV stimulates hepatic cell death a role for the metabolites of efavirenz in this process has yet to be examined. In the present study, incubation of primary human hepatocytes with synthetic 8-hydroxyEFV (8-OHEFV), which is the primary metabolite of EFV, resulted in cell death, caspase-3 activation and reactive oxygen species formation. The metabolite exerted these effects at earlier time points and using lower concentrations than were required for the parent compound. In addition, pharmacological inhibitionmore » of cytochrome P450-dependent metabolism of EFV using 1-aminobenzotriazole markedly decreased reactive oxygen species formation and cell death. Treatment of primary human hepatocytes with EFV and 8-OHEFV also stimulated phosphorylation of c-Jun N-terminal kinase (JNK) as well as phosphorylation of the JNK substrate c-Jun. Further, the mRNA and protein expression of an isoform of Bim (Bcl-2 interacting mediator of cell death) denoted as BimEL, which is proapoptotic and has been shown to be modulated by JNK, was increased. Inhibition of JNK using SP600125 prevented the EFV- and 8-OHEFV-mediated cell death. Silencing of Bim using siRNA transfected into hepatocytes also prevented cell death resulting from 8-OHEFV-treatment. These data suggest that the oxidative metabolite 8-OHEFV is a more potent inducer of hepatic cell death than the parent compound EFV. Further, activation of the JNK signaling pathway and BimEL mRNA expression appear to be required for EFV- and 8-OHEFV-mediated hepatocyte death. -- Highlights: Black-Right-Pointing-Pointer 8-Hydroxyefavirenz is a more potent stimulator of cell death than efavirenz. Black-Right-Pointing-Pointer Efavirenz and 8-hydroxyefavirenz increase JNK activity and BimEL mRNA expression. Black-Right-Pointing-Pointer JNK and Bim are required for efavirenz- and

  12. Early intracellular signaling events induced by in vitro metreleptin administration in cardiac myocytes and uterine smooth muscle cells.

    PubMed

    Choi, S K; Park, S; Choi, Y; Moon, H-S

    2015-08-05

    Intracellular signaling pathways regulated by leptin have largely been studied in metabolically important organs such as adipose tissue and peripheral blood mononuclear cells, suggesting that leptin plays a key role in pathophysiology of insulin resistance. However, whether synthetic analog of leptin, metreleptin, has similar effects on cardiac myocytes (CM) and uterine smooth muscle cells (USMC) has not yet been studied. Hence, in order to address these questions, we extended previous observations and investigated in vitro signaling study whether metreleptin may activate key signaling pathways. We observed that metreleptin activates Jak2 and STAT3 signaling pathways in dose- and time-dependent manner in CM and USMC. Also, we found that metreleptin increases ERK1/2, JNK and/or p38 phosphorylation in CM. In vitro metreleptin administration also increased ERK1/2 and/or p38 phosphorylation in USMC. By contrast, JNK was not regulated by in vitro metreleptin administration in USMC. Moreover, metreleptin-activated all signaling pathways were blocked by pre-treatment of PD98095 (ERK inhibitor), SB203580 (p38 inhibitor) and/or SP600125 (JNK inhibitor), respectively. Finally, metreleptin increased cell size (hypertrophy) in both CM and USMC. Our data provide novel insights into the role of Jak2, STAT3, ERK1/2, JNK and/or p38 as probable mediators of the action of leptin in regulating hypertrophy in CM and USMC.

  13. Power Frequency Magnetic Fields Affect the p38 MAPK-Mediated Regulation of NB69 Cell Proliferation Implication of Free Radicals.

    PubMed

    Martínez, María Antonia; Úbeda, Alejandro; Moreno, Jorge; Trillo, María Ángeles

    2016-04-06

    The proliferative response of the neuroblastoma line NB69 to a 100 µT, 50 Hz magnetic field (MF) has been shown mediated by activation of the MAPK-ERK1/2 pathway. This work investigates the MF effect on the cell cycle of NB69, the participation of p38 and c-Jun N-terminal (JNK) kinases in the field-induced proliferative response and the potential involvement of reactive oxygen species (ROS) in the activation of the MAPK-ERK1/2 and -p38 signaling pathways. NB69 cultures were exposed to the 100 µT MF, either intermittently for 24, 42 or 63 h, or continuously for periods of 15 to 120 min, in the presence or absence of p38 or JNK inhibitors: SB203580 and SP600125, respectively. Antioxidant N-acetylcysteine (NAC) was used as ROS scavenger. Field exposure induced transient activation of p38, JNK and ERK1/2. The MF proliferative effect, which was mediated by changes in the cell cycle, was blocked by the p38 inhibitor, but not by the JNK inhibitor. NAC blocked the field effects on cell proliferation and p38 activation, but not those on ERK1/2 activation. The MF-induced proliferative effects are exerted through sequential upregulation of MAPK-p38 and -ERK1/2 activation, and they are likely mediated by a ROS-dependent activation of p38.

  14. 50 CFR 600.125 - Budgeting, funding, and accounting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Budgeting, funding, and accounting. 600.125 Section 600.125 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Regional Fishery Management...

  15. 50 CFR 600.125 - Budgeting, funding, and accounting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Budgeting, funding, and accounting. 600.125 Section 600.125 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Regional Fishery Management...

  16. Apoptosis and autophagy induced by pyropheophorbide-α methyl ester-mediated photodynamic therapy in human osteosarcoma MG-63 cells.

    PubMed

    Huang, Qiu; Ou, Yun-Sheng; Tao, Yong; Yin, Hang; Tu, Ping-Hua

    2016-06-01

    Pyropheophorbide-α methyl ester (MPPa) was a second-generation photosensitizer with many potential applications. Here, we explored the impact of MPPa-mediated photodynamic therapy (MPPa-PDT) on the apoptosis and autophagy of human osteosarcoma (MG-63) cells as well as the relationships between apoptosis and autophagy of the cells, and investigated the related molecular mechanisms. We found that MPPa-PDT demonstrated the ability to inhibit MG-63 cell viability in an MPPa concentration- and light dose-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, MPPa-PDT could also induce autophagy of MG-63 cell. Meanwhile, the ROS scavenger N-acetyl-L-cysteine (NAC) and the Jnk inhibitor SP600125 were found to inhibit the MPPa-PDT-induced autophagy, and NAC could also inhibit Jnk phosphorylation. Furthermore, pretreatment with the autophagy inhibitor 3-methyladenine or chloroquine showed the potential in reducing the apoptosis rate induced by MPPa-PDT in MG-63 cells. Our results indicated that the mitochondrial pathway was involved in MPPa-PDT-induced apoptosis of MG-63 cells. Meanwhile the ROS-Jnk signaling pathway was involved in MPPa-PDT-induced autophagy, which further promoted the apoptosis in MG-63 cells.

  17. 3,3'-Diindolylmethane is a novel mitochondrial H(+)-ATP synthase inhibitor that can induce p21(Cip1/Waf1) expression by induction of oxidative stress in human breast cancer cells.

    PubMed

    Gong, Yixuan; Sohn, Heesook; Xue, Ling; Firestone, Gary L; Bjeldanes, Leonard F

    2006-05-01

    Epidemiologic evidence suggests that high dietary intake of Brassica vegetables, such as broccoli, cabbage, and Brussels sprouts, protects against tumorigenesis in multiple organs. 3,3'-Diindolylmethane, one of the active products derived from Brassica vegetables, is a promising antitumor agent. Previous studies in our laboratory showed that 3,3'-diindolylmethane induced a G(1) cell cycle arrest in human breast cancer MCF-7 cells by a mechanism that included increased expression of p21. In the present study, the upstream events leading to p21 overexpression were further investigated. We show for the first time that 3,3'-diindolylmethane is a strong mitochondrial H(+)-ATPase inhibitor (IC(50) approximately 20 micromol/L). 3,3'-Diindolylmethane treatment induced hyperpolarization of mitochondrial inner membrane, decreased cellular ATP level, and significantly stimulated mitochondrial reactive oxygen species (ROS) production. ROS production, in turn, led to the activation of stress-activated pathways involving p38 and c-Jun NH(2)-terminal kinase. Using specific kinase inhibitors (SB203580 and SP600125), we showed the central role of p38 and c-Jun NH(2)-terminal kinase (JNK) pathways in 3,3'-diindolylmethane-induced p21 mRNA transcription. In addition, antioxidants significantly attenuated 3,3'-diindolylmethane-induced activation of p38 and JNK and induction of p21, indicating that oxidative stress is the major trigger of these events. To further support the role of ROS in 3,3'-diindolylmethane-induced p21 overexpression, we showed that 3,3'-diindolylmethane failed to induce p21 overexpression in mitochondrial respiratory chain deficient rho(0) MCF-7 cells, in which 3,3'-diindolylmethane did not stimulate ROS production. Thus, we have established the critical role of enhanced mitochondrial ROS release in 3,3'-diindolylmethane-induced p21 up-regulation in human breast cancer cells.

  18. Mitomycin C upregulates IL-8 and MCP-1 chemokine expression via mitogen-activated protein kinases in corneal fibroblasts.

    PubMed

    Chou, San-Fang; Chang, Shu-Wen; Chuang, Jia-Ling

    2007-05-01

    To investigate the expression of chemokines and their signaling pathways after application of mitomycin C (MMC) to corneal fibroblasts. Primary porcine and human corneal fibroblasts from passages 3 to 6 were treated with MMC at concentrations of 0.05, 0.1, or 0.2 mg/mL for 1, 2, 5, or 10 minutes. The relative expression of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) were investigated with reverse transcription, and quantitative real-time polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA). The effects of MMC on the activation of kinases were analyzed by Western blot analysis with specific antiphosphokinase antibodies. The signaling pathways by which MMC regulates the expression of IL-8 and MCP-1 were evaluated by pharmacological kinase-specific inhibitors. The expression of IL-8 and MCP-1 were upregulated after MMC treatment in a time- and concentration-dependent manner. Furthermore, the upregulated expression of IL-8 and MCP-1 increased with longer incubation time. MMC treatment enhanced the phosphorylation of p38, JNK, and ERK at different time points. The MMC-related IL-8 and MCP-1 expression was inhibited by both a p38 inhibitor (SB203580) and an ERK inhibitor (PD98059). A JNK inhibitor (SP600125) reduced the expression of MMC-induced MCP-1 but not of IL-8. MMC treatment upregulated the expression of IL-8 and MCP-1 mRNA and protein secretion by the activation of mitogen-activated protein kinases (MAPKs) in corneal fibroblasts.

  19. DIOL Triterpenes Block Profibrotic Effects of Angiotensin II and Protect from Cardiac Hypertrophy

    PubMed Central

    Jurado-López, Raquel; Martínez-Martínez, Ernesto; Gómez-Hurtado, Nieves; Delgado, Carmen; Visitación Bartolomé, Maria; San Román, José Alberto; Cordova, Claudia; Lahera, Vicente; Nieto, Maria Luisa; Cachofeiro, Victoria

    2012-01-01

    Background The natural triterpenes, erythrodiol and uvaol, exert anti-inflammatory, vasorelaxing and anti-proliferative effects. Angiotensin II is a well-known profibrotic and proliferative agent that participates in the cardiac remodeling associated with different pathological situations through the stimulation and proliferation of cardiac fibroblasts. Therefore, the aim of the study was to investigate the preventive effects of the natural triterpenes erythrodiol and uvaol on the proliferation and collagen production induced by angiotensin II in cardiac myofibroblasts. Their actions on cardiac hypertrophy triggered by angiotensin II were also studied. Methodology/Principal Findings The effect of erythrodiol and uvaol on angiotensin II-induced proliferation was evaluated in cardiac myofibroblasts from adult rats in the presence or the absence of the inhibitors of PPAR-γ, GW9662 or JNK, SP600125. The effect on collagen levels induced by angiotensin II was evaluated in cardiac myofibroblasts and mouse heart. The presence of low doses of both triterpenes reduced the proliferation of cardiac myofibroblasts induced by angiotensin II. Pretreatment with GW9662 reversed the effect elicited by both triterpenes while SP600125 did not modify it. Both triterpenes at high doses produced an increase in annexing-V binding in the presence or absence of angiotensin II, which was reduced by either SP600125 or GW9662. Erythrodiol and uvaol decreased collagen I and galectin 3 levels induced by angiotensin II in cardiac myofribroblasts. Finally, cardiac hypertrophy, ventricular remodeling, fibrosis, and increases in myocyte area and brain natriuretic peptide levels observed in angiotensin II-infused mice were reduced in triterpene-treated animals. Conclusions/Significance Erythrodiol and uvaol reduce cardiac hypertrophy and left ventricle remodeling induced by angiotensin II in mice by diminishing fibrosis and myocyte area. They also modulate growth and survival of cardiac

  20. Mechanisms of palmitate-induced cell death in human osteoblasts

    PubMed Central

    Gunaratnam, Krishanthi; Vidal, Christopher; Boadle, Ross; Thekkedam, Chris; Duque, Gustavo

    2013-01-01

    Summary Lipotoxicity is an overload of lipids in non-adipose tissues that affects function and induces cell death. Lipotoxicity has been demonstrated in bone cells in vitro using osteoblasts and adipocytes in coculture. In this condition, lipotoxicity was induced by high levels of saturated fatty acids (mostly palmitate) secreted by cultured adipocytes acting in a paracrine manner. In the present study, we aimed to identify the underlying mechanisms of lipotoxicity in human osteoblasts. Palmitate induced autophagy in cultured osteoblasts, which was preceded by the activation of autophagosomes that surround palmitate droplets. Palmitate also induced apoptosis though the activation of the Fas/Jun kinase (JNK) apoptotic pathway. In addition, osteoblasts could be protected from lipotoxicity by inhibiting autophagy with the phosphoinositide kinase inhibitor 3-methyladenine or by inhibiting apoptosis with the JNK inhibitor SP600125. In summary, we have identified two major molecular mechanisms of lipotoxicity in osteoblasts and in doing so we have identified a new potential therapeutic approach to prevent osteoblast dysfunction and death, which are common features of age-related bone loss and osteoporosis. PMID:24285710

  1. Power Frequency Magnetic Fields Affect the p38 MAPK-Mediated Regulation of NB69 Cell Proliferation Implication of Free Radicals

    PubMed Central

    Martínez, María Antonia; Úbeda, Alejandro; Moreno, Jorge; Trillo, María Ángeles

    2016-01-01

    The proliferative response of the neuroblastoma line NB69 to a 100 µT, 50 Hz magnetic field (MF) has been shown mediated by activation of the MAPK-ERK1/2 pathway. This work investigates the MF effect on the cell cycle of NB69, the participation of p38 and c-Jun N-terminal (JNK) kinases in the field-induced proliferative response and the potential involvement of reactive oxygen species (ROS) in the activation of the MAPK-ERK1/2 and -p38 signaling pathways. NB69 cultures were exposed to the 100 µT MF, either intermittently for 24, 42 or 63 h, or continuously for periods of 15 to 120 min, in the presence or absence of p38 or JNK inhibitors: SB203580 and SP600125, respectively. Antioxidant N-acetylcysteine (NAC) was used as ROS scavenger. Field exposure induced transient activation of p38, JNK and ERK1/2. The MF proliferative effect, which was mediated by changes in the cell cycle, was blocked by the p38 inhibitor, but not by the JNK inhibitor. NAC blocked the field effects on cell proliferation and p38 activation, but not those on ERK1/2 activation. The MF-induced proliferative effects are exerted through sequential upregulation of MAPK-p38 and -ERK1/2 activation, and they are likely mediated by a ROS-dependent activation of p38. PMID:27058530

  2. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yuan, Bo; Cui, Jinquan, E-mail: jinquancuijqc@163.com; Wang, Wuliang

    Several reports have indicated a role for the members of the G12 family of heterotrimeric G proteins (Gα12 and Gα13) in oncogenesis and tumor cell growth. The aims of the present study were to evaluate the role of G12 signaling in cervical cancer. We demonstrated that expression of the G12 proteins was highly upregulated in cervical cancer cells. Additionally, expression of the activated forms of Gα12/Gα13 but not expression of activated Gαq induced cell invasion through the activation of the RhoA family of G proteins, but had no effect on cell proliferation in the cervical cancer cells. Inhibition of G12more » signaling by expression of the RGS domain of the p115-Rho-specific guanine nucleotide exchange factor (p115-RGS) blocked thrombin-stimulated cell invasion, but did not inhibit cell proliferation in cervical cells, whereas the inhibition of Gαq (RGS2) had no effect. Furthermore, G12 signaling was able to activate Rho proteins, and this stimulation was inhibited by p115-RGS, and Gα12-induced invasion was blocked by an inhibitor of RhoA/B/C (C3 toxin). Pharmacological inhibition of JNK remarkably decreased G12-induced JNK activation. Both a JNK inhibitor (SP600125) and a ROCK inhibitor (Y27632) reduced G12-induced JNK and c-Jun activation, and markedly inhibited G12-induced cellular invasion. Collectively, these findings demonstrate that stimulation of G12 proteins is capable of promoting invasion through RhoA/ROCK-JNK activation. -- Highlights: •Gα12/Gα13 is upregulated in cervical cancer cell lines. •Gα12/Gα13 is not involved in cervical cancer cell proliferation. •Gα12/Gα13 promotes cervical cancer cell invasion. •The role of Rho G proteins in G12-promoted cervical cancer cell invasion. •G12 promotes cell invasion through activation of the ROCK-JNK signaling axis.« less

  3. Eupafolin inhibits PGE2 production and COX2 expression in LPS-stimulated human dermal fibroblasts by blocking JNK/AP-1 and Nox2/p47{sup phox} pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tsai, Ming-Horng; Lin, Zih-Chan; Liang, Chan-Jung

    2014-09-01

    Eupafolin, a major active component found in the methanol extracts of Phyla nodiflora, has been used to treat inflammation of skin. We examined its effects on cyclooxygenase-2 (COX-2) expression in LPS-treated human dermal fibroblasts. Lipopolysaccharide (LPS) significantly increased prostaglandin-E2 (PGE2) production associated with increased COX-2 expression in Hs68 cells. This effect was blocked by eupafolin, TLR-4 antibody, antioxidants (APO and NAC), as well as inhibitors, including U0126 (ERK1/2), SB202190 (p38), SP600125 (JNK1/2), and Tanshinone IIA (AP-1). In gene regulation level, qPCR and promoter assays revealed that COX-2 expression was attenuated by eupafolin. In addition, eupafolin also ameliorated LPS-induced p47 phoxmore » activation and decreased reactive oxygen species (ROS) generation and NADPH oxidase (Nox) activity. Moreover, pretreatment with eupafolin and APO led to reduced LPS-induced phosphorylation of ERK1/2, JNK, and p38. Further, eupafolin attenuated LPS-induced increase in AP-1 transcription factor binding activity as well as the increase in the phosphorylation of c-Jun and c-Fos. In vivo studies have shown that in dermal fibroblasts of LPS treated mice, eupafolin exerted anti-inflammation effects by decreasing COX-2 protein levels. Our results reveal a novel mechanism for anti-inflammatory and anti-oxidative effects of eupafolin that involved inhibition of LPS-induced ROS generation, suppression of MAPK phosphorylation, diminished DNA binding activity of AP-1 and attenuated COX-2 expression leading to reduced production of prostaglandin E2 (PGE2). Our results demonstrate that eupafolin may be used to treat inflammatory responses associated with dermatologic diseases. - Highlights: • LPS activates the Nox2/p47{sup phox}/JNK/AP-1 and induces COX2 expression in Hs68 cells. • Eupafolin inhibits LPS-induced COX-2 expression via Nox2/p47{sup phox} inhibition. • Eupafolin may be used in the treatment of skin diseases involving

  4. Functional characterization of CXCR4 in mediating the expression of protein C system in experimental ulcerative colitis

    PubMed Central

    Lin, Xuhong; Wang, Huichao; Li, Yuxia; Yang, Jingnan; Yang, Ruilin; Wei, Dandan; Zhang, Junjie; Yang, Desheng; Wang, Bin; Ren, Xuequn; Cheng, Guanchang

    2017-01-01

    The present study aimed to explore the role of CXCR4 and protein C system (PCS) in the experimental ulcerative colitis (UC). The expression of CXCR3, CCR10, and CXCR4 in dextran sulfate sodium (DSS)-induced colitis mouse model was measured by immunohistochemistry and western blot analysis. In vitro studies with microvascular endothelial cells (MVECs) were performed. The expression of endothelial protein C receptor (EPCR) and thrombomodulin (TM) were detected by RT-PCR and western blot analysis. Activities of protein C (PC), protein S (PS), activated PC (APC) were evaluated in cells pre-treated with JNK inhibitor SP600125 and c-Jun silencing. DSS mice showed up-regulated expression of CXCR4, higher macroscopic score and histological score (P<0.05), as well as elevated levels of SDF-1α (P<0.05) compared with wild type, CXCR4-/-, or CXCR4-/- +DSS mice. In DSS mice, EPCR expression was down-regulated (P<0.05), accompanied by decreased activity of PC and PS (P<0.05 or P<0.01) with an up-regulated expression of pJNK MAPK and pc-Jun (P<0.05). Moreover, the macroscopic score and histological score index, SDF-1α levels, EPCR expression, PC activity, pJNK, and pc-Jun were reversed in CXCR4-/- +DSS mice (P<0.05). In vitro, SDF-1α-induced inhibition of the PCS was blunted by SP600125 (P<0.05). Meanwhile, down-regulation of c-Jun rescued the inhibition of PCS (P<0.05). MVECs with retrovirus-mediated transfection of c-Jun demonstrated a strong trans-inactivation effect on the EPCR promoter (P<0.05). These findings suggest that CXCR4 is involved in UC pathogenesis and could be a promising therapeutic target for UC treatment. PMID:29218082

  5. Secreted phospholipase A2 of Clonorchis sinensis activates hepatic stellate cells through a pathway involving JNK signalling.

    PubMed

    Wu, Yinjuan; Li, Ye; Shang, Mei; Jian, Yu; Wang, Caiqin; Bardeesi, Adham Sameer A; Li, Zhaolei; Chen, Tingjin; Zhao, Lu; Zhou, Lina; He, Ai; Huang, Yan; Lv, Zhiyue; Yu, Xinbing; Li, Xuerong

    2017-03-16

    Secreted phospholipase A2 (sPLA2) is a protein secreted by Clonorchis sinensis and is a component of excretory and secretory products (CsESPs). Phospholipase A2 is well known for its role in liver fibrosis and inhibition of tumour cells. The JNK signalling pathway is involved in hepatic stellate cells (HSCs) activation. Blocking JNK activity with SP600125 inhibits HSCs activation. In a previous study, the protein CssPLA2 was expressed in insoluble inclusion bodies. Therefore, it's necessary to express CssPLA2 in water-soluble form and determine whether the enzymatic activity of CssPLA2 or cell signalling pathways is involved in liver fibrosis caused by clonorchiasis. Balb/C mice were given an abdominal injection of MBP-CssPLA2. Liver sections with HE and Masson staining were observed to detect accumulation of collagen. Western blot of mouse liver was done to detect the activation of JNK signalling pathway. In vitro, HSCs were incubated with MBP-CssPLA2 to detect the activation of HSCs as well as the activation of JNK signalling pathway. The mutant of MBP-CssPLA2 without enzymatic activity was constructed and was also incubated with HSCs to check whether activation of the HSCs was related to the enzymatic activity of MBP-CssPLA2. The recombinant protein MBP-CssPLA2 was expressed soluble and of good enzymatic activity. A mutant of CssPLA2, without enzymatic activity, was also constructed. In vivo liver sections of Balb/C mice that were given an abdominal injection of 50 μg/ml MBP-CssPLA2 showed an obvious accumulation of collagen and a clear band of P-JNK1 could be seen by western blot of the liver tissue. In vitro, MBP-CssPLA2, as well as the mutant, was incubated with HSCs and it was proved that activation of HSCs was related to activation of the JNK signalling pathway instead of the enzymatic activity of MBP-CssPLA2. Activation of HSCs by CssPLA2 is related to the activation of the JNK signalling pathway instead of the enzymatic activity of CssPLA2. This finding

  6. Differential regulation of CD44 expression by lipopolysaccharide (LPS) and TNF-alpha in human monocytic cells: distinct involvement of c-Jun N-terminal kinase in LPS-induced CD44 expression.

    PubMed

    Gee, Katrina; Lim, Wilfred; Ma, Wei; Nandan, Devki; Diaz-Mitoma, Francisco; Kozlowski, Maya; Kumar, Ashok

    2002-11-15

    Alterations in the regulation of CD44 expression play a critical role in modulating cell adhesion, migration, and inflammation. LPS, a bacterial cell wall component, regulates CD44 expression and may modulate CD44-mediated biological effects in monocytic cells during inflammation and immune responses. In this study, we show that in normal human monocytes, LPS and LPS-induced cytokines IL-10 and TNF-alpha enhance CD44 expression. To delineate the mechanism underlying LPS-induced CD44 expression, we investigated the role of the mitogen-activated protein kinases (MAPKs), p38, p42/44 extracellular signal-regulated kinase, and c-Jun N-terminal kinase (JNK) by using their specific inhibitors. We demonstrate the involvement, at least in part, of p38 MAPK in TNF-alpha-induced CD44 expression in both monocytes and promonocytic THP-1 cells. However, neither p38 nor p42/44 MAPKs were involved in IL-10-induced CD44 expression in monocytes. To further dissect the TNF-alpha and LPS-induced signaling pathways regulating CD44 expression independent of IL-10-mediated effects, we used IL-10 refractory THP-1 cells as a model system. Herein, we show that CD44 expression induced by the LPS-mediated pathway predominantly involved JNK activation. This conclusion was based on results derived by transfection of THP-1 cells with a dominant-negative mutant of stress-activated protein/extracellular signal-regulated kinase kinase 1, and by exposure of cells to JNK inhibitors dexamethasone and SP600125. All these treatments prevented CD44 induction in LPS-stimulated, but not in TNF-alpha-stimulated, THP-1 cells. Furthermore, we show that CD44 induction may involve JNK-dependent early growth response gene activation in LPS-stimulated monocytic cells. Taken together, these results suggest a predominant role of JNK in LPS-induced CD44 expression in monocytic cells.

  7. Retinol induces morphological alterations and proliferative focus formation through free radical-mediated activation of multiple signaling pathways.

    PubMed

    Gelain, Daniel Pens; Pasquali, Matheus Augusto de Bittencourt; Caregnato, Fernanda Freitas; Castro, Mauro Antonio Alves; Moreira, José Claudio Fonseca

    2012-04-01

    Toxicity of retinol (vitamin A) has been previously associated with apoptosis and/or cell malignant transformation. Thus, we investigated the pathways involved in the induction of proliferation, deformation and proliferative focus formation by retinol in cultured Sertoli cells of rats. Sertoli cells were isolated from immature rats and cultured. The cells were subjected to a 24-h treatment with different concentrations of retinol. Parameters of oxidative stress and cytotoxicity were analyzed. The effects of the p38 inhibitor SB203580 (10 μmol/L), the JNK inhibitor SP600125 (10 μmol/L), the Akt inhibitor LY294002 (10 μmol/L), the ERK inhibitor U0126 (10 μmol/L) the pan-PKC inhibitor Gö6983 (10 μmol/L) and the PKA inhibitor H89 (1 μmol/L) on morphological and proliferative/transformation-associated modifications were studied. Retinol (7 and 14 μmol/L) significantly increases the reactive species production in Sertoli cells. Inhibition of p38, JNK, ERK1/2, Akt, and PKA suppressed retinol-induced [(3)H]dT incorporation into the cells, while PKC inhibition had no effect. ERK1/2 and p38 inhibition also blocked retinol-induced proliferative focus formation in the cells, while Akt and JNK inhibition partially decreased focus formation. ERK1/2 and p38 inhibition hindered transformation-associated deformation in retinol-treated cells, while other treatments had no effect. Our results suggest that activation of multiple kinases is responsible for morphological and proliferative changes associated to malignancy development in Sertoli cells by retinol at the concentrations higher than physiological level.

  8. Active lipids of Ganoderma lucidum spores-induced apoptosis in human leukemia THP-1 cells via MAPK and PI3K pathways.

    PubMed

    Wang, Jia-He; Zhou, Yi-Jun; Zhang, Meng; Kan, Liang; He, Ping

    2012-01-31

    Ganoderma lucidum (Lingzhi) is traditionally drug, which has been traditionally effective used in the treatment of chronic hepatopathy, hypertension, hyperglycemia and cancer. THP-1 and HL-60 apoptosis induced by active lipids of Ganoderma lucidum spores was quantified by flow cytometry using FITC-conjugated annexin V and PI; MAPK and Akt were measured by Western blot, and caspase-3, -8 and -9 activities were also detected by spectrophotometric assay. Our results showed that active lipids of Ganoderma lucidum spores decreased phosphorylation-ERK1/2 (P-ERK1/2), P-Akt and increased P-JNK1/2, but did not affect expressions of P-p38 MAPK in THP-1 cells. Moreover, treatment of THP-1 cells with active lipids of Ganoderma lucidum spores resulted in activation of caspase-3, -8 and -9. Furthermore, LY294002 (Akt inhibitor) or PD98059 (ERK1/2 inhibitor) significantly enhanced active lipids of Ganoderma lucidum spores-induced apoptosis in THP-1 cells, whereas caspase inhibitors or SP600125 (JNK inhibitor), decreased apoptosis in THP-1 cells. Taken together, our study for the first time suggests that active lipids of Ganoderma lucidum spores is able to enhance apoptosis in THP-1 cells, at least in part, through inhibition of ERK1/2, Akt and activation of JNK1/2 signaling pathways. Moreover, it also triggers caspase-3, -8 and -9 activation mediated apoptotic induction. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  9. Ultrasound Stimulation of Different Dental Stem Cell Populations: Role of Mitogen-activated Protein Kinase Signaling.

    PubMed

    Gao, Qianhua; Walmsley, A Damien; Cooper, Paul R; Scheven, Ben A

    2016-03-01

    Mesenchymal stem cells (MSCs) from dental tissues may respond to low-intensity pulsed ultrasound (LIPUS) treatment, potentially providing a therapeutic approach to promoting dental tissue regeneration. This work aimed to compare LIPUS effects on the proliferation and MAPK signaling in MSCs from rodent dental pulp stem cells (DPSCs) compared with MSCs from periodontal ligament stem cells (PDLSCs) and bone marrow stem cells (BMSCs). Isolated MSCs were treated with 1-MHz LIPUS at an intensity of 250 or 750 mW/cm2 for 5 or 20 minutes. Cell proliferation was evaluated by 5-bromo-2-deoxyuridine (BrdU) staining after 24 hours of culture following a single LIPUS treatment. Specific ELISAs were used to determine the total and activated p38, ERK1/2, and JNK MAPK signaling proteins up to 4 hours after treatment. Selective MAPK inhibitors PD98059 (ERK1/2), SB203580 (p38), and SP600125 (JNK) were used to determine the role of activation of the particular MAPK pathways. The proliferation of all MSC types was significantly increased after LIPUS treatment. LIPUS at a 750-mW/cm2 dose induced the greatest effects on DPSCs. BMSC proliferation was stimulated in equal measures by both intensities, whereas 250 mW/cm2 LIPUS exposure exerted maximum effects on PDLSCs. ERK1/2 was activated immediately in DPSCs after treatment. Concomitantly, DPSC proliferation was specifically modulated by ERK1/2 inhibition, whereas p38 and JNK inhibition exerted no effects. In BMSCs, JNK MAPK signaling was LIPUS activated, and the increase in proliferation was blocked by specific inhibition of the JNK pathway. In PDLSCs, JNK MAPK signaling was activated immediately after LIPUS, whereas p-p38 MAPK increased significantly in these cells 4 hours after exposure. Correspondingly, JNK and p38 inhibition modulated LIPUS-stimulated PDLSC proliferation. LIPUS promoted MSC proliferation in an intensity and cell-specific dependent manner via activation of distinct MAPK pathways. Copyright © 2016 American

  10. Pioglitazone inhibits advanced glycation end product-induced matrix metalloproteinases and apoptosis by suppressing the activation of MAPK and NF-κB.

    PubMed

    Zhang, Hai-Bin; Zhang, Ying; Chen, Cheng; Li, Yu-Qing; Ma, Chi; Wang, Zhao-Jun

    2016-10-01

    Apoptosis and degeneration coming mainly from chondrocytes are important mechanisms in the onset and progression of osteoarthritis. Specifically, advanced glycation end products (AGEs) play an important role in the pathogenesis of osteoarthritis. Pioglitazone, a peroxisome proliferator-activated receptor γ (PPARγ) agonist has a protective effect on cartilage. This study aims to evaluate the effect of pioglitazone on AGEs-induced chondrocyte apoptosis and degeneration and their underlying mechanism. The in vitro study shows that AGEs induce cleavage of caspase-3 and PARP, up-regulate MMP-13 expression, enhance chondrocyte apoptosis and down-regulate PPARγ expression in human primary chondrocytes, which is reversed by pioglitazone. Furthermore, AGEs activate phosphorylation of Erk, JNK, and p38, and pioglitazone reverses AGEs-induced phosphorylation of Erk and p38. AGEs-induced degradation of IκBα and translocation of nuclear NF-κB p65 is reversed by pioglitazone. Pretreatment of chondrocytes with SB202190 (p38 inhibitor), SP600125 (JNK inhibitor) and BAY-11-7082 (NF-κB inhibitor) inhibit AGEs-induced apoptosis and degeneration. In vivo experiments suggest that pioglitazone reverses AGEs-induced cartilage degeneration and apoptosis in a mouse model, as demonstrated by HE and Safranin O staining, immunohistochemical analyses of Type II collagen (Col II), metalloproteinases (MMPs) and caspase-3. These findings suggest that pioglitazone, a PPARγ agonist, inhibits AGEs-induced chondrocytes apoptosis and degeneration via suppressing the activation of MAPK and NF-κB.

  11. Joint inhibition of TOR and JNK pathways interacts to extend the lifespan of Brachionus manjavacas (Rotifera)

    PubMed Central

    Snell, Terry W.; Johnston, Rachel K.; Rabeneck, Brett; Zipperer, Cody; Teat, Stephanie

    2014-01-01

    The TOR kinase pathway is central in modulating aging in a variety of animal models. The target of rapamycin (TOR) integrates a complex network of signals from growth conditions, nutrient availability, energy status, and physiological stresses and matches an organism’s growth rate to the resource environment. Important problems remaining are to identify the pathways that interact with TOR and characterize them as additive or synergistic. One of the most versatile stress sensors in metazoans is the Jun-N-terminal Kinase (JNK) signalling pathway. JNK is an evolutionarily conserved stress-activated protein kinase that is induced by a range of stressors, including UV irradiation, reactive oxygen species, DNA damage, heat, and bacterial antigens. JNK is thought to interact with the TOR pathway, but its effects on TOR are poorly understood. We used the rotifer Brachionus manjavacas as a model animal to probe the regulation of TOR and JNK pathways and explore their interaction. The effect of various chemical inhibitors was examined in life table and stressor challenge experiments. A survey of 12 inhibitors revealed two, rapamycin and JNK inhibitor, that significantly extended lifespan of B. manjavacas. At 1 μM concentration, exposure to rapamycin or JNK inhibitor extended mean rotifer lifespan by 35% and maximum lifespan by 37%. Exposure to both rapamycin and JNK inhibitor simultaneously extended mean rotifer lifespan 65% more than either alone. Exposure to a combination of rapamycin and JNK inhibitors conveyed greater protection to starvation, UV and osmotic stress than either inhibitor alone. RNAi knockdown of TOR and JNK gene expression was investigated for its ability to extend rotifer lifespan. RNAi knockdown of the TOR gene resulted in 29% extension of mean lifespan compared to control and knockdown of the JNK gene resulted in 51% mean lifespan extension. In addition to lifespan, we quantified mitochondria activity using the fluorescent marker Mitotracker and

  12. Oxidative stress-driven mechanisms of nordihydroguaiaretic acid-induced apoptosis in FL5.12 cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Deshpande, Vaidehee S.; Kehrer, James P.

    2006-08-01

    Nordihydroguaiaretic acid (NDGA), a general lipoxygenase (LOX) enzyme inhibitor, induces apoptosis independently of its activity as a LOX inhibitor in murine pro-B lymphocytes (FL.12 cells) by a mechanism that is still not fully understood. Glutathione depletion, oxidative processes and mitochondrial depolarization appear to contribute to the apoptosis induced by NDGA. The current data demonstrate that NDGA (20 {mu}M)-induced apoptosis in FL5.12 cells is partially protected by N-acetylcysteine (NAC) (10 mM) and dithiothreitol (DTT) (500 {mu}M) pretreatment, confirming a role for oxidative processes. In addition, the treatment of FL5.12 cells with NDGA led to an increase in phosphorylation and activation ofmore » the MAP kinases ERK, JNK and p38. Although pretreatment with ERK inhibitors (PD98059 or U0126) abolished ERK phosphorylation in response to NDGA, neither inhibitor had any effect on NDGA-induced apoptosis. SP600125, a JNK inhibitor, did not have any effect on NDGA-induced phosphorylation of JNK nor apoptosis. Pretreatment with the p38 inhibitor SB202190 attenuated NDGA-induced apoptosis by 30% and also abolished p38 phosphorylation, compared to NDGA treatment alone. NAC, but not DTT, also decreased the phosphorylation of p38 and JNK supporting a role for oxidative processes in activating these kinases. Neither NAC nor DTT blocked the phosphorylation of ERK suggesting that this activation is not related to oxidative stress. The release of cytochrome c and activation of caspase-3 induced by NDGA were inhibited by NAC. SB202190 slightly attenuated caspase-3 activation and had no effect on the release of cytochrome c. These data suggest that several independent mechanisms, including oxidative reactions, activation of p38 kinase and cytochrome c release contribute to NDGA-induced apoptosis.« less

  13. Formononetin attenuates osteoclastogenesis via suppressing the RANKL-induced activation of NF-κB, c-Fos, and nuclear factor of activated T-cells cytoplasmic 1 signaling pathway.

    PubMed

    Huh, Jeong-Eun; Lee, Wong In; Kang, Jung Won; Nam, Dongwoo; Choi, Do-Young; Park, Dong-Suk; Lee, Sang Hoon; Lee, Jae-Dong

    2014-11-26

    Formononetin (1), a plant-derived phytoestrogen, possesses bone protective properties. To address the potential therapeutic efficacy and mechanism of action of 1, we investigated its antiosteoclastogenic activity and its effect on nuclear factor-kappaB ligand (RANKL)-induced bone-marrow-derived macrophages (BMMs). Compound 1 markedly inhibited RANKL-induced osteoclast differentiation in the absence of cytotoxicity, by regulating the expression of osteoprotegerin (OPG) and RANKL in BMMs and in cocultured osteoblasts. Compound 1 significantly inhibited RANKL-induced tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T cell expressed and secreted (RANTES), and macrophage inflammatory protein-1α (MIP-1α) in a concentration-dependent manner. These effects were accompanied by a decrease in RANKL-induced activation of the NF-κB p65 subunit, degradation of inhibitor κBα (IκBα), induction of NF-κB, and phosphorylation of AKT, extracellular-signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK). NF-κB siRNA suppressed AKT, ERK, JNK, and p38 MAPK phosphorylation. Furthermore, 1 significantly suppressed c-Fos and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), key transcription factors during osteoclastogenesis. SP600125, a specific inhibitor of JNK, reduced RANKL-induced expression of phospho-c-Jun, c-Fos, and NFATc1 and inhibited osteoclast formation. These results suggested that 1 acted as an antiresorption agent by blocking osteoclast activation.

  14. Anti-inflammatory effects of secondary metabolites of marine Pseudomonas sp. in human neutrophils are through inhibiting P38 MAPK, JNK, and calcium pathways.

    PubMed

    Yang, Shun-Chin; Sung, Ping-Jyun; Lin, Chwan-Fwu; Kuo, Jimmy; Chen, Chun-Yu; Hwang, Tsong-Long

    2014-01-01

    Activated neutrophils play a significant role in the pathogenesis of many inflammatory diseases. The metabolites of marine microorganisms are increasingly employed as sources for developing new drugs; however, very few marine drugs have been studied in human neutrophils. Herein, we showed that secondary metabolites of marine Pseudomonas sp. (N11) significantly inhibited superoxide anion generation and elastase release in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-activated human neutrophils, with IC50 values of 0.67±0.38 µg/ml and 0.84±0.12 µg/ml, respectively. In cell-free systems, neither superoxide anion-scavenging effect nor inhibition of elastase activity was associated with the suppressive effects of N11. N11 inhibited the phosphorylation of p38 MAP kinase and JNK, but not Erk and Akt, in FMLP-induced human neutrophils. Also, N11 dose-dependently attenuated the transient elevation of intracellular calcium concentration in activated neutrophils. In contrast, N11 failed to alter phorbol myristate acetate-induced superoxide anion generation, and the inhibitory effects of N11 were not reversed by protein kinase A inhibitor. In conclusion, the anti-inflammatory effects of N11 on superoxide anion generation and elastase release in activated human neutrophils are through inhibiting p38 MAP kinase, JNK, and calcium pathways. Our results suggest that N11 has the potential to be developed to treat neutrophil-mediated inflammatory diseases.

  15. Compound C induces protective autophagy in human cholangiocarcinoma cells via Akt/mTOR-independent pathway.

    PubMed

    Zhao, Xiaofang; Luo, Guosong; Cheng, Ying; Yu, Wenjing; Chen, Run; Xiao, Bin; Xiang, Yuancai; Feng, Chunhong; Fu, Wenguang; Duan, Chunyan; Yao, Fuli; Xia, Xianming; Tao, Qinghua; Wei, Mei; Dai, Rongyang

    2018-07-01

    Compound C, a well-known inhibitor of AMP-activated protein kinase (AMPK), has been reported to exert antitumor activities in some types of cells. Whether compound C can exert antitumor effects in human cholangiocarcinoma (CCA) remains unknown. Here, we demonstrated that compound C is a potent inducer of cell death and autophagy in human CCA cells. Autophagy inhibitors increased the cytotoxicity of compound C towards human CCA cells, as confirmed by increased LDH release, and PARP cleavage. It is notable that compound C treatment increased phosphorylated Akt, sustained high levels of phosphorylated p70S6K, and decreased mTOR regulated p-ULK1 (ser757). Based on the data that blocking PI3K/Akt or mTOR had no apparent influence on autophagic response, we suggest that compound C induces autophagy independent of Akt/mTOR signaling in human CCA cells. Further study demonstrated that compound C inhibited the phosphorylation of JNK and its target c-Jun. Blocking JNK by SP600125 or siRNA suppressed autophagy induction upon compound C treatment. Moreover, compound C induced p38 MAPK activation, and its inhibition promoted autophagy induction via JNK activation. In addition, compound C induced p53 expression, and its inhibition attenuated compound C-induced autophagic response. Thus, compound C triggers autophagy, at least in part, via the JNK and p53 pathways in human CCA cells. In conclusion, suppresses autophagy could increase compound C sensitivity in human CCA. © 2018 Wiley Periodicals, Inc.

  16. Moringa oleifera fruit induce apoptosis via reactive oxygen species-dependent activation of mitogen-activated protein kinases in human melanoma A2058 cells

    PubMed Central

    Guon, Tae Eun; Chung, Ha Sook

    2017-01-01

    The present study was performed to determine the effect of Moringa oleifera fruit extract on the apoptosis of human melanoma A2058 cells. A2058 cells were treated for 72 h with Moringa oleifera fruit extract at 50–100 µg/ml, and cell viability with apoptotic changes was examined. The involvement of reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs) was examined. It was revealed that Moringa oleifera fruit extract significantly inhibited the cell viability and promoted apoptosis of A2058 cells in a concentration-dependent manner. Moringa oleifera fruit extract-treated A2058 cells exhibited increased activities of cleaved caspase-9 and caspase-3. It also caused an enhancement of MAPK phosphorylation and ROS production. The pro-apoptotic activity of Moringa oleifera fruit extract was significantly reversed by pretreatment with the c-Jun N-terminal kinase (JNK) inhibitor SP600125, extracellular-signal-regulated kinase (ERK) inhibitor PD98058 or ROS inhibitor N-acetyl-L-cysteine. Taken together, Moringa oleifera fruit extract is effective in inducing mitochondrial apoptosis of A2058 cells, which is mediated through induction of ROS formation, and JNK and ERK activation. Moringa oleifera fruit extract may thus have therapeutic benefits for human melanoma A2058 cells. PMID:28789398

  17. Moringa oleifera fruit induce apoptosis via reactive oxygen species-dependent activation of mitogen-activated protein kinases in human melanoma A2058 cells.

    PubMed

    Guon, Tae Eun; Chung, Ha Sook

    2017-08-01

    The present study was performed to determine the effect of Moringa oleifera fruit extract on the apoptosis of human melanoma A2058 cells. A2058 cells were treated for 72 h with Moringa oleifera fruit extract at 50-100 µg/ml, and cell viability with apoptotic changes was examined. The involvement of reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs) was examined. It was revealed that Moringa oleifera fruit extract significantly inhibited the cell viability and promoted apoptosis of A2058 cells in a concentration-dependent manner. Moringa oleifera fruit extract-treated A2058 cells exhibited increased activities of cleaved caspase-9 and caspase-3. It also caused an enhancement of MAPK phosphorylation and ROS production. The pro-apoptotic activity of Moringa oleifera fruit extract was significantly reversed by pretreatment with the c-Jun N-terminal kinase (JNK) inhibitor SP600125, extracellular-signal-regulated kinase (ERK) inhibitor PD98058 or ROS inhibitor N-acetyl-L-cysteine. Taken together, Moringa oleifera fruit extract is effective in inducing mitochondrial apoptosis of A2058 cells, which is mediated through induction of ROS formation, and JNK and ERK activation. Moringa oleifera fruit extract may thus have therapeutic benefits for human melanoma A2058 cells.

  18. 17β-Estradiol and Agonism of G-protein-Coupled Estrogen Receptor Enhance Hippocampal Memory via Different Cell-Signaling Mechanisms

    PubMed Central

    Kim, Jaekyoon; Szinte, Julia S.; Boulware, Marissa I.

    2016-01-01

    The ability of 17β-estradiol (E2) to enhance hippocampal object recognition and spatial memory depends on rapid activation of extracellular signal-regulated kinase (ERK) in the dorsal hippocampus (DH). Although this activation can be mediated by the intracellular estrogen receptors ERα and ERβ, little is known about the role that the membrane estrogen receptor GPER plays in regulating ERK or E2-mediated memory formation. In this study, post-training DH infusion of the GPER agonist G-1 enhanced object recognition and spatial memory in ovariectomized female mice, whereas the GPER antagonist G-15 impaired memory, suggesting that GPER activation, like E2, promotes hippocampal memory formation. However, unlike E2, G-1 did not increase ERK phosphorylation, but instead significantly increased phosphorylation of c-Jun N-terminal kinase (JNK) in the DH. Moreover, DH infusion of the JNK inhibitor SP600125 prevented G-1 from enhancing object recognition and spatial memory, but the ERK inhibitor U0126 did not. These data suggest that GPER enhances memory via different cell-signaling mechanisms than E2. This conclusion was supported by data showing that the ability of E2 to facilitate memory and activate ERK signaling was not blocked by G-15 or SP600125, which demonstrates that the memory-enhancing effects of E2 are not dependent on JNK or GPER activation in the DH. Together, these data indicate that GPER regulates memory independently from ERα and ERβ by activating JNK signaling, rather than ERK signaling. Thus, the findings suggest that GPER in the DH may not function as an estrogen receptor to regulate object recognition and spatial memory. SIGNIFICANCE STATEMENT Although 17β-estradiol has long been known to regulate memory function, the molecular mechanisms underlying estrogenic memory modulation remain largely unknown. Here, we examined whether the putative membrane estrogen receptor GPER acts like the classical estrogen receptors, ERα and ERβ, to facilitate

  19. Alpinia oxyphylla Miquel fruit extract activates MAPK-mediated signaling of PAs and MMP2/9 to induce Schwann cell migration and nerve regeneration.

    PubMed

    Chang, Yung-Ming; Ye, Chi-Xin; Ho, Tsung-Jung; Tsai, Te-Neng; Chiu, Ping-Ling; Tsai, Chin-Chuan; Lin, Yueh-Min; Kuo, Chia-Hua; Tsai, Fuu-Jen; Tsai, Chang-Hai; Huang, Chih-Yang

    2014-05-01

    This study investigates the molecular mechanisms by which Alpiniae oxyphyllae fructus (AOF) promotes neuron regeneration. A piece of silicone rubber was guided across a 15 mm gap in the sciatic nerve of a rat. This nerve gap was then filled with different concentrations of AOF extract (0-200 mg/ml). We investigated the role of MAPK (ERK1/2, JNK and p38) pathways for AOF-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in RSC96 Schwann cells. The results showed that AOF increased the expressions of uPA, tPA, MMP-9, and MAPKs in vivo. In vitro, our results show that treatment with AOF extract induces ERK1/2, JNK, and p38 phosphorylation to activate the downstream PAs and MMPs signaling expression. AOF-stimulated ERK1/2, JNK, and p38 phosphorylation attenuated by individual pretreatment with siRNAs or inhibitors (U0126, SP600125 and SB203580), resulting in migration and uPA-related signal pathway inhibition. Taken together our data suggests the MAPKs (ERK1/2, JNK and p38), PAs (uPA, tPA), MMP (MMP2, MMP9) regenerative and migration signaling pathway of Schwann cells regulated by AOF extract might play a major role in Schwann cell migration and damaged peripheral nerve regeneration.

  20. Tangeretin suppresses IL-1beta-induced cyclooxygenase (COX)-2 expression through inhibition of p38 MAPK, JNK, and AKT activation in human lung carcinoma cells.

    PubMed

    Chen, Kuan-Hung; Weng, Meng-Shih; Lin, Jen-Kun

    2007-01-15

    Tangeretin (5,6,7,8,4'-pentamethoxyflavone) is a polymethoxylated flavonoid concentrated in the peel of citrus fruits. Recent studies have shown that tangeretin exhibits anti-proliferative, anti-invasive, anti-metastatic, and antioxidant activities. However, the anti-inflammatory properties of tangeretin are unclear. In this study, we examine the effects of tangeretin and its structure-related compound, nobiletin, on the expression of cyclooxygenases-2 (COX-2) in human lung epithelial carcinoma cells, A549, and human non-small cell lung carcinoma cells, H1299. Tangeretin exerts a much better inhibitory activity than nobiletin against IL-1beta-induced production of COX-2 in A549 cells, and it effectively represses the constitutively expressed COX-2 in H1299. RT-PCR was used to investigate the transcriptional inhibition of COX-2 by tangeretin. COX-2 mRNA was rapidly induced by IL-1beta in 3h and markedly suppressed by tangeretin. IL-1beta-induced the activation of ERK, p38 MAPK, JNK, and AKT in A549 cells. COX-2 expression in response to IL-1beta was attenuated by pretreatment with SB203580, SP600125, and LY294002, but not with PD98059, suggesting the involvement of p38 MAPK, JNK, and PI3K in this response. Pretreatment of cells with tangeretin inhibited IL-1beta-induced p38 MAPK, JNK, and AKT phosphorylation and the downstream activation of NF-kappaB. These results may reveal that the tangeretin inhibition of IL-1beta-induced COX-2 expression in A549 cells is, at least in part, mediated through suppression of NF-kappaB transcription factor as well as through suppression of the signaling proteins of p38 MAPK, JNK, and PI3K, but not of ERK.

  1. Involvement of MAPKs, NF-{kappa}B and p300 co-activator in IL-1{beta}-induced cytosolic phospholipase A{sub 2} expression in canine tracheal smooth muscle cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luo, S.-F.; Lin, C.-C.; Chen, H.-C.

    2008-11-01

    Cytosolic phospholipase A{sub 2} (cPLA{sub 2}) plays a pivotal role in mediating agonist-induced arachidonic acid release for prostaglandin (PG) synthesis during stimulation with interleukin-1{beta} (IL-1{beta}). However, the mechanisms underlying IL-1{beta}-induced cPLA{sub 2} expression and PGE{sub 2} synthesis by canine tracheal smooth muscle cells (CTSMCs) have not been defined. IL-1{beta} induced cPLA{sub 2} protein and mRNA expression, PGE{sub 2} production, and phosphorylation of p42/p44 MAPK, p38 MAPK (ATF{sub 2}), and JNK (c-Jun) in a time- and concentration-dependent manner, determined by Western blotting, RT-PCR, and ELISA, which was attenuated by the inhibitors of MEK1/2 (U0126), p38 MAPK (SB202190), and JNK (SP600125), ormore » transfection with dominant negative mutants of MEK1/2, p38, and JNK, respectively. Furthermore, IL-1{beta}-induced cPLA{sub 2} expression and PGE{sub 2} synthesis was inhibited by a selective NF-{kappa}B inhibitor (helenalin) or transfection with dominant negative mutants of NF-{kappa}B inducing kinase (NIK), I{kappa}B kinase (IKK)-{alpha}, and IKK-{beta}. Consistently, IL-1{beta} stimulated both I{kappa}B-{alpha} degradation and NF-{kappa}B translocation into nucleus in these cells. NF-{kappa}B translocation was blocked by helenalin, but not by U0126, SB202190, and SP600125. MAPKs together with NF-{kappa}B-activated p300 recruited to cPLA{sub 2} promoter thus facilitating the binding of NF-{kappa}B to cPLA{sub 2} promoter region and expression of cPLA{sub 2} mRNA. IL-1{beta}-induced cPLA{sub 2} expression and PGE{sub 2} production was inhibited by actinomycin D and cycloheximide, indicating the involvement of transcriptional and translational events in these responses. These results suggest that in CTSMCs, IL-1{beta}-induced cPLA{sub 2} expression and PGE{sub 2} synthesis was independently mediated through activation of MAPKs and NF-{kappa}B pathways and was connected to p300 recruitment and activation.« less

  2. JNK: bridging the insulin signaling and inflammatory pathway.

    PubMed

    Liu, Gang; Rondinone, Cristina M

    2005-10-01

    Obesity and insulin resistance are strongly associated with systemic markers of inflammation and endoplasmic reticulum stress. c-Jun N-terminal kinases (JNK) are activated by inflammatory cytokines and have a key role in beta-cell apoptosis and in negative regulation of insulin signaling. JNK1-deficient mice are protected from diet-induced obesity and insulin resistance, while genetically obese mice with targeted mutations in JNK1 are leaner and have reduced insulin and blood glucose levels. These studies validate JNK as a link between inflammation and metabolic diseases and as a promising drug target. This review highlights recent advances in small-molecule inhibitors of JNK that have also been targeted for other diseases with an inflammatory component such as stroke, rheumatoid arthritis, and Alzheimer's and Parkinson's diseases.

  3. atRA-induced apoptosis of mouse embryonic palate mesenchymal cells involves activation of MAPK pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yu Zengli; Xing Ying

    2006-08-15

    Our previous studies have shown that atRA treatment resulted in cell-cycle block and growth inhibition in mouse embryonic palatal mesenchymal (MEPM). In the current study, gestation day (GD) 13 MEPM cells were used to test the hypothesis that the growth inhibition by atRA is due to apoptosis. The effects of atRA on apoptosis were assessed by performing MTT assay, Cell Death Detection ELISA and flow cytometry, respectively. Data analysis confirmed that atRA treatment induced apoptosis-like cell death, as shown by decreased cell viability and increased fragmented DNA and sub-G1 fraction. atRA-induced apoptosis was associated with upregulation of bcl-2, translocation ofmore » bax protein to the mitochondria from the cytosol, activation of caspase-3 and cytochrome c release into cytosol. atRA-induced apoptosis was abrogated by z-DEVD-fmk, a caspase-3 specific inhibitor, and z-VAD-fmk, a general caspase inhibitor, suggesting that the atRA-induced cell death of MEPM cells occurs through the cytochrome c- and caspase-3-dependent pathways. In addition, atRA treatment caused a strong and sustained activation of c-Jun N-terminal kinase (JNK) and p38 kinase (p38), as well as an early but transient activation of extracellular signal-regulated kinase (ERK). Importantly, atRA-induced DNA fragmentation and capase-3 activation were prevented by pretreatment with the JNK inhibitor (SP600125) and the p38 MAPK inhibitor (SB202190), but not by pretreatment with MEK inhibitor (U0126). From these results, we suggest that mitogen-activated protein kinase-dependent pathways is involved in the atRA-induced apoptosis of MEPM cells.« less

  4. ACE as a Mechanosensor to Shear Stress Influences the Control of Its Own Regulation via Phosphorylation of Cytoplasmic Ser1270

    PubMed Central

    Barauna, Valerio Garrone; Campos, Luciene Cristina Gastalho; Miyakawa, Ayumi Aurea; Krieger, Jose Eduardo

    2011-01-01

    Objectives We tested whether angiotensin converting enzyme (ACE) and phosphorylation of Ser1270 are involved in shear-stress (SS)-induced downregulation of the enzyme. Methods and Results Western blotting analysis showed that SS (18 h, 15 dyn/cm2) decreases ACE expression and phosphorylation as well as p-JNK inhibition in human primary endothelial cells (EC). CHO cells expressing wild-type ACE (wt-ACE) also displayed SS-induced decrease in ACE and p-JNK. Moreover, SS decreased ACE promoter activity in wt-ACE, but had no effect in wild type CHO or CHO expressing ACE without either the extra- or the intracellular domains, and decreased less in CHO expressing a mutated ACE at Ser1270 compared to wt-ACE (13 vs. 40%, respectively). The JNK inhibitor (SP600125, 18 h), in absence of SS, also decreased ACE promoter activity in wt-ACE. Finally, SS-induced inhibition of ACE expression and phosphorylation in EC was counteracted by simultaneous exposure to an ACE inhibitor. Conclusions ACE displays a key role on its own downregulation in response to SS. This response requires both the extra- and the intracellular domains and ACE Ser1270, consistent with the idea that the extracellular domain behaves as a mechanosensor while the cytoplasmic domain elicits the downstream intracellular signaling by phosphorylation on Ser1270. PMID:21901117

  5. Phosphoproteomics reveals ALK promote cell progress via RAS/ JNK pathway in neuroblastoma.

    PubMed

    Chen, Kai; Lv, Fan; Xu, Guofeng; Zhang, Min; Wu, Yeming; Wu, Zhixiang

    2016-11-15

    Emerging evidence suggests receptor tyrosine kinase ALK as a promising therapeutic target in neuroblastoma. However, clinical trials reveal that a limited proportion of ALK-positive neuroblastoma patients experience clinical benefits from Crizotinib, a clinically approved specific inhibitor of ALK. The precise molecular mechanisms of aberrant ALK activity in neuroblastoma remain elusive, limiting the clinical application of ALK as a therapeutic target in neuroblastoma. Here, we describe a deep quantitative phosphoproteomic approach in which Crizotinib-treated neuroblastoma cell lines bearing aberrant ALK are used to investigate downstream regulated phosphoproteins. We identified more than 19,500-and quantitatively analyzed approximately 10,000-phosphorylation sites from each cell line, ultimately detecting 450-790 significantly-regulated phosphorylation sites. Multiple layers of bioinformatic analysis of the significantly-regulated phosphoproteins identified RAS/JNK as a downstream signaling pathway of ALK, independent of the ALK variant present. Further experiments demonstrated that ALK/JNK signaling could be inactivated by either ALK- or JNK-specific inhibitors, resulting in cell growth inhibition by induction of cell cycle arrest and cell apoptosis. Our study broadly defines the phosphoproteome in response to ALK inhibition and provides a resource for further clinical investigation of ALK as therapeutic target for the treatment of neuroblastoma.

  6. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peng, C.-H.; Department of Nursing, Hungkuang University, Sha Lu, Taichung, Taiwan; Tseng, T.-H.

    In our previous study, penta-acetyl geniposide ((AC){sub 5}GP) is suggested to induce tumor cell apoptosis through the specific activation of PKC{delta}. However, the downstream signal pathway of PKC{delta} has not yet been investigated. It was shown that JNK may play an important role in the regulation of apoptosis and could be a possible downstream signal of PKC{delta} isoforms. In the present study, we investigate whether JNK is involved in (AC){sub 5}GP induced apoptosis. The result reveals that (AC){sub 5}GP induces JNK activation and c-Jun phosphorylation thus stimulating the expression of Fas-L and Fas. Using SP600125 to block JNK activation showsmore » that (AC){sub 5}GP-mediated apoptosis and related proteins expression are attenuated. Furthermore, we find that the (AC){sub 5}GP induces apoptosis through the activation of JNK/Jun/Fas L/Fas/caspase 8/caspase 3, a mitochondria-independent pathway. The JNK pathway is suggested to be the downstream signal of PKC{delta}, since rottlerin impedes (AC){sub 5}GP-induced JNK activation. Therefore, (AC){sub 5}GP mediates cell death via activation of PKC{delta}/JNK/FasL cascade signaling.« less

  7. Quinoxalinylurea derivatives as a novel class of JSP-1 inhibitors.

    PubMed

    Zhang, Li; Qiu, Beiying; Xiong, Bing; Li, Xin; Li, Jingya; Wang, Xin; Li, Jia; Shen, Jingkang

    2007-04-15

    A series of quinoxalinylurea-based inhibitors are synthesized and shown to be the novel and potent inhibitors against Jnk Stimulatory Phosphatase-1 (JSP-1), which is a special member of dual-specificity protein phosphatase (DSP) family. Biological assay and computational modeling studies showed the compounds were reversible and noncompetitive inhibitors of JSP-1. JSP-1 inhibitors may be useful for the treatment of inflammatory, vascular, neurodegenerative, metabolic, and oncological diseases in humans associated with dysfunctional Jnk signaling.

  8. Cisplatin induces expression of drug resistance-related genes through c-jun N-terminal kinase pathway in human lung cancer cells.

    PubMed

    Xu, Li; Fu, Yingya; Li, Youlun; Han, Xiaoli

    2017-08-01

    Change of multidrug resistance-related genes (e.g., lung resistance protein, LRP) and overexpression of anti-apoptotic genes (Bcl-2, Bcl-Xl, XIAP, Survivin) are responsible for cisplatin resistance. In our study, we investigated the mechanism by which cisplatin induces LRP, Bcl-2, Bcl-xL, XIAP, and Survivin expression in human lung adenocarcinoma A549 cells and human H446 small cell lung cancer cells at mRNA and protein levels. In our study, cell proliferation was assessed with CCK-8 assays, and cell apoptosis was assessed with flow cytometric analysis and Annexin-V/PI staining. qPCR was used to complete RNA experiments. Protein expression was assessed with Western blotting. Cisplatin increased Bcl-2, LRP, and Survivin expression, but decreased Bcl-xL and XIAP expression in a dose-dependent manner. Preincubation with JNK-specific inhibitor, SP600125, significantly inhibited these genes' expression at mRNA and protein levels, enhanced chemosensitivity of lung cancer cells to cisplatin, and promoted cisplatin-induced apoptosis. Our data suggest that the JNK signaling pathway plays an important role in cisplatin resistance. Lung resistance protein (LRP) and anti-apoptotic genes (Bcl-2, Bcl-Xl, XIAP, Survivin) are involved in the process. The results reminded us of a novel therapy target for lung cancer treatment.

  9. Anthrapyrazolone analogues intercept inflammatory JNK signals to moderate endotoxin induced septic shock

    NASA Astrophysics Data System (ADS)

    Prasad, Karothu Durga; Trinath, Jamma; Biswas, Ansuman; Sekar, Kanagaraj; Balaji, Kithiganahalli N.; Guru Row, Tayur N.

    2014-11-01

    Severe sepsis or septic shock is one of the rising causes for mortality worldwide representing nearly 10% of intensive care unit admissions. Susceptibility to sepsis is identified to be mediated by innate pattern recognition receptors and responsive signaling pathways of the host. The c-Jun N-terminal Kinase (JNK)-mediated signaling events play critical role in bacterial infection triggered multi-organ failure, cardiac dysfunction and mortality. In the context of kinase specificities, an extensive library of anthrapyrazolone analogues has been investigated for the selective inhibition of c-JNK and thereby to gain control over the inflammation associated risks. In our comprehensive biochemical characterization, it is observed that alkyl and halogen substitution on the periphery of anthrapyrazolone increases the binding potency of the inhibitors specifically towards JNK. Further, it is demonstrated that hydrophobic and hydrophilic interactions generated by these small molecules effectively block endotoxin-induced inflammatory genes expression in in vitro and septic shock in vivo, in a mouse model, with remarkable efficacies. Altogether, the obtained results rationalize the significance of the diversity oriented synthesis of small molecules for selective inhibition of JNK and their potential in the treatment of severe sepsis.

  10. Pro-life role for c-Jun N-terminal kinase and p38 mitogen-activated protein kinase at rostral ventrolateral medulla in experimental brain stem death

    PubMed Central

    2012-01-01

    , rather than Elk-1 at Ser383 in RVLM were also augmented during the pro-life phase. Furthermore, pretreatment by microinjection into the bilateral RVLM of specific JNK inhibitors, JNK inhibitor I (100 pmol) or SP600125 (5 pmol), or specific p38MAPK inhibitors, p38MAPK inhibitor III (500 pmol) or SB203580 (2 nmol), exacerbated the depressor effect and blunted the augmented life-and-death signal exhibited during the pro-life phase. On the other hand, pretreatment with the negative control for JNK or p38MAPK inhibitor, JNK inhibitor I negative control (100 pmol) or SB202474 (2 nmol), was ineffective in the vehicle-controls and Mev-treatment groups. Conclusions Our results demonstrated that activation of JNK or p38MAPK in RVLM by their upstream activators MAP2K4 or MAP2K6 plays a preferential pro-life role by sustaining the central cardiovascular regulatory machinery during experimental brain stem death via phosphorylation and activation of nuclear transcription factor ATF-2 or c-Jun. PMID:23157661

  11. Pro-life role for c-Jun N-terminal kinase and p38 mitogen-activated protein kinase at rostral ventrolateral medulla in experimental brain stem death.

    PubMed

    Chang, Alice Y W

    2012-11-17

    Ser383 in RVLM were also augmented during the pro-life phase. Furthermore, pretreatment by microinjection into the bilateral RVLM of specific JNK inhibitors, JNK inhibitor I (100 pmol) or SP600125 (5 pmol), or specific p38MAPK inhibitors, p38MAPK inhibitor III (500 pmol) or SB203580 (2 nmol), exacerbated the depressor effect and blunted the augmented life-and-death signal exhibited during the pro-life phase. On the other hand, pretreatment with the negative control for JNK or p38MAPK inhibitor, JNK inhibitor I negative control (100 pmol) or SB202474 (2 nmol), was ineffective in the vehicle-controls and Mev-treatment groups. Our results demonstrated that activation of JNK or p38MAPK in RVLM by their upstream activators MAP2K4 or MAP2K6 plays a preferential pro-life role by sustaining the central cardiovascular regulatory machinery during experimental brain stem death via phosphorylation and activation of nuclear transcription factor ATF-2 or c-Jun.

  12. SL4, a chalcone-based compound, induces apoptosis in human cancer cells by activation of the ROS/MAPK signalling pathway.

    PubMed

    Wang, L-H; Li, H-H; Li, M; Wang, S; Jiang, X-R; Li, Y; Ping, G-F; Cao, Q; Liu, X; Fang, W-H; Chen, G-L; Yang, J-Y; Wu, C-F

    2015-12-01

    SL4, a chalcone-based compound, exhibits clearly inhibitory effects on HIF-1 and has been shown to effectively suppress tumour invasion and angiogenesis in vitro and in vivo. Here, studies were conducted to determine SL4's anti-apoptotic effects and its underlying mechanisms, in human cancer cells. Cytotoxicity, apoptotic induction and its involved mechanisms of SL4 were investigated using normal cells, cancer cells and mouse xenograft models. The role of reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK) signalling in SL4-induced apoptosis was explored by manipulating specific scavenger or signalling inhibitors, in cultured cells. SL4 significantly inhibited cell population growth of human cancer cell lines but exhibited lower cytotoxicity against normal cells. In addition, SL4 effectively induced apoptosis of Hep3B and MDA-MB-435 cells by activating procaspase-8, -9 and -3, and down-regulating expression levels of XIAP, but did not affect HIF-1 apoptosis-related targets, Survivin and Bcl-XL. Further study showed that SL4 also reduced mitochondrial membrane potential and promoted generation of ROS. ROS generation and apoptotic induction by SL4 were blocked by NAC, a scavenger of ROS, suggesting SL4-induced apoptosis via ROS accumulation. We also found that MAPKs, JNK and p38, but not ERK1/2, to be critical mediators in SL4-induced apoptosis. SP600125 and SB203580, specific inhibitors of JNK kinase and p38 kinase, significantly retarded apoptosis induced by SL4. Moreover, anti-oxidant NAC blocked activation of JNK and p38 induced by SL4, indicating that ROS may act as upstream signalling of JNK and p38 activation. It is noteworthy that animal studies revealed dramatic reduction (49%) in tumour volume after 11 days SL4 treatment. These data demonstrate that SL4 induced apoptosis in human cancer cells through activation of the ROS/MAPK signalling pathway, suggesting that it may be a novel lead compound, as a cancer drug candidate, with

  13. Transforming growth factor-beta and platelet-derived growth factor signal via c-Jun N-terminal kinase-dependent Smad2/3 phosphorylation in rat hepatic stellate cells after acute liver injury.

    PubMed

    Yoshida, Katsunori; Matsuzaki, Koichi; Mori, Shigeo; Tahashi, Yoshiya; Yamagata, Hideo; Furukawa, Fukiko; Seki, Toshihito; Nishizawa, Mikio; Fujisawa, Junichi; Okazaki, Kazuichi

    2005-04-01

    After liver injury, transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF) regulate the activation of hepatic stellate cells (HSCs) and tissue remodeling. Mechanisms of PDGF signaling in the TGF-beta-triggered cascade are not completely understood. TGF-beta signaling involves phosphorylation of Smad2 and Smad3 at linker and C-terminal regions. Using antibodies to distinguish Smad2/3 phosphorylated at linker regions from those phosphorylated at C-terminal regions, we investigated Smad2/3-mediated signaling in rat liver injured by CCl(4) administration and in cultured HSCs. In acute liver injury, Smad2/3 were transiently phosphorylated at both regions. Although linker-phosphorylated Smad2 remained in the cytoplasm of alpha-smooth muscle actin-immunoreactive mesenchymal cells adjacent to necrotic hepatocytes in centrilobular areas, linker-phosphorylated Smad3 accumulated in the nuclei. c-Jun N-terminal kinase (JNK) in the activated HSCs directly phosphorylated Smad2/3 at linker regions. Co-treatment of primary cultured HSCs with TGF-beta and PDGF activated the JNK pathway, subsequently inducing endogenous linker phosphorylation of Smad2/3. The JNK pathway may be involved in migration of resident HSCs within the space of Disse to the sites of tissue damage because the JNK inhibitor SP600125 inhibited HSC migration induced by TGF-beta and PDGF signals. Moreover, treatment of HSCs with both TGF-beta and PDGF increased transcriptional activity of plasminogen activator inhibitor-1 through linker phosphorylation of Smad3. In conclusion, TGF-beta and PDGF activate HSCs by transmitting their signals through JNK-mediated Smad2/3 phosphorylation at linker regions, both in vivo and in vitro.

  14. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Qiang; Song, Xin-mao; Ji, Yang-yang

    Highlights: •AZD8055 induces significant cytotoxic effects in cultured HNSCC cells. •AZD8055 blocks mTORC1 and mTORC2 activation in cultured HNSCC cells. •JNK activation is required for AZD8055-induced HNSCC cell death. •AZD8055 inhibits Hep-2 cell growth in vivo, and was more efficient than rapamycin. -- Abstract: The serine/threonine kinase mammalian target of rapamycin (mTOR) promotes cell survival and proliferation, and is constitutively activated in head and neck squamous cell carcinoma (HNSCC). Thus mTOR is an important target for drug development in this disease. Here we tested the anti-tumor ability of AZD8055, the novel mTOR inhibitor, in HNSCC cells. AZD8055 induced dramatic cellmore » death of HNSCC lines (Hep-2 and SCC-9) through autophagy. AZD8055 blocked both mTOR complex (mTORC) 1 and mTORC2 activation without affecting Erk in cultured HNSCC cells. Meanwhile, AZD8055 induced significant c-Jun N-terminal kinase (JNK) activation, which was also required for cancer cell death. JNK inhibition by its inhibitors (SP 600125 and JNK-IN-8), or by RNA interference (RNAi) alleviated AZD8055-induced cell death. Finally, AZD8055 markedly increased the survival of Hep-2 transplanted mice through a significant reduction of tumor growth, without apparent toxicity, and its anti-tumor ability was more potent than rapamycin. Meanwhile, AZD8055 administration activated JNK while blocking mTORC1/2 in Hep-2 tumor engrafts. Our current results strongly suggest that AZD8055 may be further investigated for HNSCC treatment in clinical trials.« less

  15. Formononetin upregulates nitric oxide synthase in arterial endothelium through estrogen receptors and MAPK pathways.

    PubMed

    Sun, Tao; Cao, Lei; Ping, Na-Na; Wu, Yue; Liu, Dong-Zheng; Cao, Yong-Xiao

    2016-03-01

    Formononetin, a phytoestrogen, can improve arterial endothelial cell function by upregulating endothelial nitric oxide synthase (eNOS). The estrogen receptor plays an important role in the regulation of eNOS. This study investigated the hypothesis that formononetin upregulates eNOS through estrogen receptors and MAPK pathways. The rat superior mesenteric arteries were cultured with formononetin or formononetin plus inhibitors for 24 h. The isometric tension of the arteries was measured using a myograph system. The mRNA and protein expression levels of eNOS were determined by real-time PCR and immunohistochemistry, respectively. Acetylcholine (ACh) relaxed the mesenteric arteries precontracted with 5-hydroxytryptamine. This relaxation could be enhanced by formononetin. The removal of endothelium or incubation with l-NAME (a NOS inhibitor) completely abolished the formononetin-enhanced relaxation induced by ACh, suggesting that the formononetin-enhanced vasodilatation is dependent on endothelium and NO pathway. The estrogen receptor inhibitor ICI 182780 attenuated the formononetin-enhanced vasodilatation induced by ACh, suggesting that the formononetin-enhanced arterial relaxation is mediated by the estrogen receptor. Formononetin increased the mRNA and protein expression levels of eNOS. ICI 182780, U0126 (an ERK1/2 inhibitor) and SP600125 (a JNK inhibitor) prevented the increases in arterial relaxation and eNOS levels. Formononetin upregulates eNOS expression in mesenteric arteries via estrogen receptors, ERK1/2 and JNK pathways. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

  16. Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis.

    PubMed

    Yang, Jung-Bo; Quan, Juan-Hua; Kim, Ye-Eun; Rhee, Yun-Ee; Kang, Byung-Hyun; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min; Lee, Young-Ha

    2015-08-01

    Trichomonas vaginalis; induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in TNF-α production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased TNF-α production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, TNF-α production was significantly decreased compared to the control; however, TNF-α reduction patterns were different depending on the type of PI3K/MAPK inhibitors. TNF-α production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of TNF-α production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.

  17. Inhibition of JNK Sensitizes Hypoxic Colon Cancer Cells to DNA Damaging Agents

    PubMed Central

    Vasilevskaya, Irina A.; Selvakumaran, Muthu; Hierro, Lucia Cabal; Goldstein, Sara R.; Winkler, Jeffrey D.; O'Dwyer, Peter J.

    2015-01-01

    Purpose We showed previously that in HT29 colon cancer cells, modulation of hypoxia-induced stress signaling affects oxaliplatin cytotoxicity. To further study the significance of hypoxia-induced signaling through JNK, we set out to investigate how modulation of kinase activities influences cellular responses of hypoxic colon cancer cells to cytotoxic drugs. Experimental design In a panel of cell lines we investigated effects of pharmacological and molecular inhibition of JNK on sensitivity to oxaliplatin, SN-38 and 5-FU. Combination studies for the drugs and JNK inhibitor CC-401 were carried out in vitro and in vivo. Results Hypoxia-induced JNK activation was associated with resistance to oxaliplatin. CC-401 in combination with chemotherapy demonstrates synergism in colon cancer cell lines, though synergy is not always hypoxia-specific. A more detailed analysis focused on HT29 and SW620 (responsive), and HCT116 (non-responsive) lines. In HT29 and SW620 cells CC-401 treatment results in greater DNA damage in the sensitive cells. In vivo, potentiation of bevacizumab, oxaliplatin, and the combination by JNK inhibition was confirmed in HT29-derived mouse xenografts, where tumor growth delay was greater in the presence of CC-401. Finally, stable introduction of a dominant negative JNK1, but not JNK2, construct into HT29 cells rendered them more sensitive to oxaliplatin under hypoxia, suggesting differing input of JNK isoforms in cellular responses to chemotherapy. Conclusions These findings demonstrate that signaling through JNK is a determinant of response to therapy in colon cancer models, and support the testing of JNK inhibition to sensitize colon tumors in the clinic. PMID:26023085

  18. Ambient ultrafine particles reduce endothelial nitric oxide production via S-glutathionylation of eNOS.

    PubMed

    Du, Yunfeng; Navab, Mohamad; Shen, Melody; Hill, James; Pakbin, Payam; Sioutas, Constantinos; Hsiai, Tzung K; Li, Rongsong

    2013-07-05

    Exposure to airborne particulate pollutants is intimately linked to vascular oxidative stress and inflammatory responses with clinical relevance to atherosclerosis. Particulate matter (PM) has been reported to induce endothelial dysfunction and atherosclerosis. Here, we tested whether ambient ultrafine particles (UFP, diameter <200 nm) modulate eNOS activity in terms of nitric oxide (NO) production via protein S-glutathionylation. Treatment of human aortic endothelial cells (HAEC) with UFP significantly reduced NO production. UFP-mediated reduction in NO production was restored in the presence of JNK inhibitor (SP600125), NADPH oxidase inhibitor (Apocynin), anti-oxidant (N-acetyl cysteine), and superoxide dismutase mimetics (Tempol and MnTMPyP). UFP exposure increased the GSSG/GSH ratio and eNOS S-glutathionylation, whereas over-expression of Glutaredoxin-1 (to inhibit S-glutathionylation) restored UFP-mediated reduction in NO production by nearly 80%. Thus, our findings suggest that eNOS S-glutathionylation is a potential mechanism underlying ambient UFP-induced reduction of NO production. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Ambient ultrafine particles reduce endothelial nitric oxide production via S-glutathionylation of eNOS

    PubMed Central

    Du, Yunfeng; Navab, Mohamad; Shen, Melody; Hill, James; Pakbin, Payam; Sioutas, Constantinos; Hsiai, Tzung; Li, Rongsong

    2013-01-01

    Exposure to airborne particulate pollutants is intimately linked to vascular oxidative stress and inflammatory responses with clinical relevance to atherosclerosis. Particulate matter (PM) has been reported to induce endothelial dysfunction and atherosclerosis. Here, we tested whether ambient ultrafine particles (UFP, diameter < 200 nm) modulate eNOS activity in terms of nitric oxide (NO) production via protein S-glutathionylation. Treatment of human aortic endothelial cells (HAEC) with UFP significantly reduced NO production. UFP-mediated reduction in NO production was restored in the presence of JNK inhibitor (SP600125), NADPH oxidase inhibitor (Apocynin), anti-oxidant (N-acetyl cysteine), and superoxide dismutase mimetics (Tempol and MnTMPyP). UFP exposure increased the GSSG/GSH ratio and eNOS S-glutathionylation, whereas over-expression of Glutaredoxin-1 (to inhibit S-glutathionylation) restored UFP-mediated reduction in NO production by nearly 80%. Thus, our findings suggest that eNOS S-glutathionylation is a potential mechanism underlying ambient UFP-induced reduction of NO production. PMID:23751346

  20. Angiotensin II increases Pax-2 expression in fetal kidney cells via the AT2 receptor.

    PubMed

    Zhang, Shao-Ling; Moini, Babak; Ingelfinger, Julie R

    2004-06-01

    Although both the renin angiotensin system (RAS) and the paired homeobox 2 gene (Pax-2) seem critically important in renal organogenesis, whether and how they might interact has not been addressed. The present study asked whether a link between the RAS and Pax-2 exists in fetal renal cells, speculating that such an interaction, if present, might influence renal development. Embryonic kidney explants and embryonic renal cells (mouse late embryonic mesenchymal epithelial cells [MK4] and mouse early embryonic mesenchymal fibroblasts [MK3]) were used. Pax-2 protein and Pax-2 mRNA were detected by immunofluorescence, Western blot, reverse transcription-PCR, and real-time PCR. Angiotensin II (AngII) upregulated Pax-2 protein and Pax-2 mRNA expression via the AngII type 2 (AT(2)) receptor in MK4 but not in MK3 cells. The stimulatory effect of AngII on Pax-2 gene expression could be blocked by PD123319 (AT(2) inhibitor), AG 490 (a specific Janus kinase 2 inhibitor), and genistein (a tyrosine kinase inhibitor) but not by losartan (AT(1) inhibitor), SB203580 (specific p38 mitogen-activated protein kinase inhibitor), PD98059 (specific MEK inhibitor), SP600125 (JNK inhibitor), and diphenyleneiodonium chloride (an NADPH oxidase inhibitor). Moreover, embryonic kidney explants in culture confirmed that AngII upregulates Pax-2 gene expression via the AT(2) receptor. These studies demonstrate that the stimulatory effect of AngII on Pax-2 gene expression is mediated, at least in part, via the Janus kinase 2/signal transducers and activators of transcription signaling transduction pathway, suggesting that RAS and Pax-2 interactions may be important in renal development.

  1. Activation of the EGFR/p38/JNK Pathway by Mitochondrial-Derived Hydrogen Peroxide Contributes To Oxygen-induced Contraction Of Ductus Arteriosus

    PubMed Central

    Hong, Zhigang; Cabrera, Jésus A; Mahapatra, Saswati; Kutty, Shelby; Weir, E. Kenneth; Archer, Stephen L.

    2014-01-01

    Oxygen-induced contraction of the ductus arteriosus (DA) involves a mitochondrial oxygen-sensor, which signals pO2 in the DA smooth muscle cell (DASMC) by increasing production of diffusible hydrogen peroxide (H2O2). H2O2 stimulates vasoconstriction by regulating ion channels and rho kinase, leading to calcium influx and calcium sensitization. Because epidermal growth factor receptor (EGFR) signaling is also redox regulated and participates in oxygen sensing and vasoconstriction in other systems, we explored the role of the EGFR and its signaling cascade (p38 and JNK) in DA contraction. Experiments were performed in DA rings isolated from full-term New Zealand White rabbits and human DASMC. In human DASMCs increasing pO2 from hypoxia to normoxia (40 to 100 mmHg) significantly increased cytosolic calcium, p<0.01. This normoxic rise in intracellular calcium was mimicked by EGF and inhibited by EGFR siRNA. In DA rings, EGF caused contraction whilst the specific EGFR inhibitor (AG1478) and the tyrosine kinase inhibitors (genistein or tyrphostin A23) selectively attenuated oxygen-induced contraction (p <0.01). Conversely, orthovanadate, a tyrosine phosphatase inhibitor known to activate EGFR signaling, caused dose-dependent contraction of hypoxic DA and superimposed increases in oxygen caused minimal additional contraction. Ansomycin, an activator of EGFR’s downstream kinases, p38 and JNK, caused DA contraction; conversely, oxygen-induced DA contraction was blocked by inhibitors of p38 MAPK (SB203580) or JNK (JNK inhibitor II). O2-induced phosphorylation of EGFR occurred within 5-minutes of increasing pO2 and was inhibited by mitochondrial-targeted overexpression of catalase. AG1478 prevented the oxygen-induced p38 and JNK phosphorylation. In conclusion, O2-induced EGFR transactivation initiates p38/JNK-mediated increases in cytosolic calcium and contributes to DA contraction. The EGFR/p38/JNK pathway is regulated by mitochondrial redox signaling and is a promising

  2. The JNK inhibitor XG-102 protects against TNBS-induced colitis.

    PubMed

    Reinecke, Kirstin; Eminel, Sevgi; Dierck, Franziska; Roessner, Wibke; Kersting, Sabine; Chromik, Ansgar Michael; Gavrilova, Olga; Laukevicience, Ale; Leuschner, Ivo; Waetzig, Vicki; Rosenstiel, Philip; Herdegen, Thomas; Sina, Christian

    2012-01-01

    The c-Jun N-terminal kinase (JNK)-inhibiting peptide D-JNKI-1, syn. XG-102 was tested for its therapeutic potential in acute inflammatory bowel disease (IBD) in mice. Rectal instillation of the chemical irritant trinitrobenzene sulfonic acid (TNBS) provoked a dramatic acute inflammation in the colon of 7-9 weeks old mice. Coincident subcutaneous application of 100 µg/kg XG-102 significantly reduced the loss of body weight, rectal bleeding and diarrhoea. After 72 h, the end of the study, the colon was removed and immuno-histochemically analysed. XG-102 significantly reduced (i) pathological changes such as ulceration or crypt deformation, (ii) immune cell pathology such as infiltration and presence of CD3- and CD68-positive cells, (iii) the production of tumor necrosis factor (TNF)-α in colon tissue cultures from TNBS-treated mice, (iv) expression of Bim, Bax, FasL, p53, and activation of caspase 3, (v) complexation of JNK2 and Bim, and (vi) expression and activation of the JNK substrate and transcription factor c-Jun. A single application of subcutaneous XG-102 was at least as effective or even better depending on the outcome parameter as the daily oral application of sulfasalazine used for treatment of IBD.The successful and substantial reduction of the severe, TNBS-evoked intestinal damages and clinical symptoms render the JNK-inhibiting peptide XG-102 a powerful therapeutic principle of IBD.

  3. Ghrelin accelerates wound healing through GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways in combined radiation and burn injury in rats.

    PubMed

    Liu, Cong; Huang, Jiawei; Li, Hong; Yang, Zhangyou; Zeng, Yiping; Liu, Jing; Hao, Yuhui; Li, Rong

    2016-06-07

    The therapeutic effect of ghrelin on wound healing was assessed using a rat model of combined radiation and burn injury (CRBI). Rat ghrelin, anti-rat tumor necrosis factor (TNF) α polyclonal antibody (PcAb), or selective antagonists of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), and growth hormone secretagogue receptor (GHS-R) 1a (SB203580, SP600125, and [D-Lys3]-GHRP-6, respectively), were administered for seven consecutive days. Levels of various signaling molecules were assessed in isolated rat peritoneal macrophages. The results showed that serum ghrelin levels and levels of macrophage glucocorticoid receptor (GR) decreased, while phosphorylation of p38MAPK, JNK, and p65 nuclear factor (NF) κB increased. Ghrelin inhibited the serum induction of proinflammatory mediators, especially TNF-α, and promoted wound healing in a dose-dependent manner. Ghrelin treatment decreased phosphorylation of p38MAPK, JNK, and p65NF-κB, and increased GR levels in the presence of GHS-R1a. SB203580 or co-administration of SB203580 and SP600125 decreased TNF-α level, which may have contributed to the inactivation of p65NF-κB and increase in GR expression, as confirmed by western blotting. In conclusion, ghrelin enhances wound recovery in CRBI rats, possibly by decreasing the induction of TNF-α or other proinflammatory mediators that are involved in the regulation of GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways.

  4. [Over-expressed Bax inhibitor 1 (BI-1) inhibits apoptosis of hippocampal neurons via endoplasmic reticulum IRE1-JNK pathway in rats with subarachnoid hemorrhage].

    PubMed

    Liu, Jiaxin; Zhou, Shuai; Qian, Xiying; Zhang, Yueting; Zhao, Jianhua

    2017-10-01

    Objective To investigate the protective effect of lentivirus-mediated BI-1 overexpression on hippocampal neurons in rats with subarachnoid hemorrhage (SAH) and the relationship with endoplasmic reticulum IRE1-JNK signaling pathway. Methods The lentivirus solution of BI-1 over-expression was injected into the brain of rats 24 hours before SAH rat model was established by intravascular puncture method. At 24 hours after modeling, the brain water content and neurological score of the rats were measured. The apoptosis of hippocampal neurons was detected by TUNEL assay. Western blotting was used to detect the expressions of BI-1 protein and endoplasmic reticulum stress (ERS) marker proteins GRP78 and IRE1. ERS in hippocampal neurons of the rats with SAH was intervened by IRE1α-specific inhibitor KIRA6, and then the protein expressions of p-IRE1, p-JNK, Bax, Bcl2 and caspase-3 were detected by Western blotting. Results BI-1 over-expression improved neurobehavioral score, decreased brain water content and hippocampal neuron apoptosis rate, and also down-regulated GRP78 and IRE1 protein levels in the rats with SAH. Both the interference of KIRA6 and the over-expression of BI-1 inhibited the expressions of p-IRE1, p-JNK, Bax and caspase-3, and promoted the expression of anti-apoptotic protein Bcl2. Conclusion Over-expression of BI-1 can inhibit the apoptosis of hippocampal neurons in rats with SAH by inhibiting the activation of ERS-mediated IRE1-JNK signaling pathway, thus ultimately attenuating the early brain injury following SAH.

  5. TNF{alpha} and IL-1{beta} are mediated by both TLR4 and Nod1 pathways in the cultured HAPI cells stimulated by LPS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zheng, Wenwen; Zheng, Xuexing; Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL 33136

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer LPS induces proinflammatory cytokine release in HAPI cells. Black-Right-Pointing-Pointer JNK pathway is dependent on TLR4 signaling to release cytokines. Black-Right-Pointing-Pointer NF-{kappa}B pathway is dependent on Nod1 signaling to release cytokines. -- Abstract: A growing body of evidence recently suggests that glial cell activation plays an important role in several neurodegenerative diseases and neuropathic pain. Microglia in the central nervous system express toll-like receptor 4 (TLR4) that is traditionally accepted as the primary receptor of lipopolysaccharide (LPS). LPS activates TLR4 signaling pathways to induce the production of proinflammatory molecules. In the present studies, we verified the LPS signaling pathwaysmore » using cultured highly aggressively proliferating immortalized (HAPI) microglial cells. We found that HAPI cells treated with LPS upregulated the expression of TLR4, phospho-JNK (pJNK) and phospho-NF-{kappa}B (pNF-{kappa}B), TNF{alpha} and IL-1{beta}. Silencing TLR4 with siRNA reduced the expression of pJNK, TNF{alpha} and IL-1{beta}, but not pNF-{kappa}B in the cells. Inhibition of JNK with SP600125 (a JNK inhibitor) decreased the expression of TNF{alpha} and IL-1{beta}. Unexpectedly, we found that inhibition of Nod1 with ML130 significantly reduced the expression of pNF-{kappa}B. Inhibition of NF-{kappa}B also reduced the expression of TNF{alpha} and IL-1{beta}. Nod1 ligand, DAP induced the upregulation of pNF-{kappa}B which was blocked by Nod1 inhibitor. These data indicate that LPS-induced pJNK is TLR4-dependent, and that pNF-{kappa}B is Nod1-dependent in HAPI cells treated with LPS. Either TLR4-JNK or Nod1-NF-{kappa}B pathways is involved in the expression of TNF{alpha} and IL-1{beta}.« less

  6. JNK inhibition reduces apoptosis and neovascularization in a murine model of age-related macular degeneration.

    PubMed

    Du, Hongjun; Sun, Xufang; Guma, Monica; Luo, Jing; Ouyang, Hong; Zhang, Xiaohui; Zeng, Jing; Quach, John; Nguyen, Duy H; Shaw, Peter X; Karin, Michael; Zhang, Kang

    2013-02-05

    Age-related macular degeneration (AMD) is the leading cause of registered blindness among the elderly and affects over 30 million people worldwide. It is well established that oxidative stress, inflammation, and apoptosis play critical roles in pathogenesis of AMD. In advanced wet AMD, although, most of the severe vision loss is due to bleeding and exudation of choroidal neovascularization (CNV), and it is well known that vascular endothelial growth factor (VEGF) plays a pivotal role in the growth of the abnormal blood vessels. VEGF suppression therapy improves visual acuity in AMD patients. However, there are unresolved issues, including safety and cost. Here we show that mice lacking c-Jun N-terminal kinase 1 (JNK1) exhibit decreased inflammation, reduced CNV, lower levels of choroidal VEGF, and impaired choroidal macrophage recruitment in a murine model of wet AMD (laser-induced CNV). Interestingly, we also detected a substantial reduction in choroidal apoptosis of JNK1-deficient mice. Intravitreal injection of a pan-caspase inhibitor reduced neovascularization in the laser-induced CNV model, suggesting that apoptosis plays a role in laser-induced pathological angiogenesis. Intravitreal injection of a specific JNK inhibitor decreased choroidal VEGF expression and reduced pathological CNV. These results suggest that JNK1 plays a key role in linking oxidative stress, inflammation, macrophage recruitment apoptosis, and VEGF production in wet AMD and pharmacological JNK inhibition offers a unique and alternative avenue for prevention and treatment of AMD.

  7. 17β-Estradiol and Agonism of G-protein-Coupled Estrogen Receptor Enhance Hippocampal Memory via Different Cell-Signaling Mechanisms.

    PubMed

    Kim, Jaekyoon; Szinte, Julia S; Boulware, Marissa I; Frick, Karyn M

    2016-03-16

    The ability of 17β-estradiol (E2) to enhance hippocampal object recognition and spatial memory depends on rapid activation of extracellular signal-regulated kinase (ERK) in the dorsal hippocampus (DH). Although this activation can be mediated by the intracellular estrogen receptors ERα and ERβ, little is known about the role that the membrane estrogen receptor GPER plays in regulating ERK or E2-mediated memory formation. In this study, post-training DH infusion of the GPER agonist G-1 enhanced object recognition and spatial memory in ovariectomized female mice, whereas the GPER antagonist G-15 impaired memory, suggesting that GPER activation, like E2, promotes hippocampal memory formation. However, unlike E2, G-1 did not increase ERK phosphorylation, but instead significantly increased phosphorylation of c-Jun N-terminal kinase (JNK) in the DH. Moreover, DH infusion of the JNK inhibitor SP600125 prevented G-1 from enhancing object recognition and spatial memory, but the ERK inhibitor U0126 did not. These data suggest that GPER enhances memory via different cell-signaling mechanisms than E2. This conclusion was supported by data showing that the ability of E2 to facilitate memory and activate ERK signaling was not blocked by G-15 or SP600125, which demonstrates that the memory-enhancing effects of E2 are not dependent on JNK or GPER activation in the DH. Together, these data indicate that GPER regulates memory independently from ERα and ERβ by activating JNK signaling, rather than ERK signaling. Thus, the findings suggest that GPER in the DH may not function as an estrogen receptor to regulate object recognition and spatial memory. Although 17β-estradiol has long been known to regulate memory function, the molecular mechanisms underlying estrogenic memory modulation remain largely unknown. Here, we examined whether the putative membrane estrogen receptor GPER acts like the classical estrogen receptors, ERα and ERβ, to facilitate hippocampal memory in female

  8. JNK pathway activation is controlled by Tao/TAOK3 to modulate ethanol sensitivity.

    PubMed

    Kapfhamer, David; King, Ian; Zou, Mimi E; Lim, Jana P; Heberlein, Ulrike; Wolf, Fred W

    2012-01-01

    Neuronal signal transduction by the JNK MAP kinase pathway is altered by a broad array of stimuli including exposure to the widely abused drug ethanol, but the behavioral relevance and the regulation of JNK signaling is unclear. Here we demonstrate that JNK signaling functions downstream of the Sterile20 kinase family gene tao/Taok3 to regulate the behavioral effects of acute ethanol exposure in both the fruit fly Drosophila and mice. In flies tao is required in neurons to promote sensitivity to the locomotor stimulant effects of acute ethanol exposure and to establish specific brain structures. Reduced expression of key JNK pathway genes substantially rescued the structural and behavioral phenotypes of tao mutants. Decreasing and increasing JNK pathway activity resulted in increased and decreased sensitivity to the locomotor stimulant properties of acute ethanol exposure, respectively. Further, JNK expression in a limited pattern of neurons that included brain regions implicated in ethanol responses was sufficient to restore normal behavior. Mice heterozygous for a disrupted allele of the homologous Taok3 gene (Taok3Gt) were resistant to the acute sedative effects of ethanol. JNK activity was constitutively increased in brains of Taok3Gt/+ mice, and acute induction of phospho-JNK in brain tissue by ethanol was occluded in Taok3Gt/+ mice. Finally, acute administration of a JNK inhibitor conferred resistance to the sedative effects of ethanol in wild-type but not Taok3Gt/+ mice. Taken together, these data support a role of a TAO/TAOK3-JNK neuronal signaling pathway in regulating sensitivity to acute ethanol exposure in flies and in mice.

  9. Penehyclidine hydrochloride regulates mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provides cardioprotection in rats with myocardial ischemia-reperfusion injury.

    PubMed

    Feng, Min; Wang, Lirui; Chang, Siyuan; Yuan, Pu

    2018-05-31

    The potential mechanism of penehyclidine hydrochloride (PHC) against myocardial ischemia-reperfusion (I/R) injury has not been fully elucidated. The aim of the present study was to reveal whether mitochondrial dynamics, apoptosis, and MAPKs were involved in the cardioprotective effect of this drug on myocardial I/R injury. Ninety healthy adult male Wistar rats were separately pretreated with normal saline (0.9%); PHC; and signal pathway blockers of MAPKs, Drp1, and Bcl-2. Coronary artery ligation and subsequent reperfusion were performed to induce myocardial I/R injury. Echocardiography was performed. Myocardial enzymes and oxidative stress markers were detected. Myocardial cell apoptotic rates and infarct sizes were measured. Mitochondrial function was evaluated. Expression levels of MAPKs, mitochondria regulatory proteins (Drp1, Mfn1/2), and apoptosis-related proteins (Bcl-2, Bax) were determined. PHC pretreatment improved myocardial abnormalities (dysfunction, injury, infarct size, and apoptotic rate), mitochondrial abnormalities (dysfunction and fission), and excessive oxidative stress and inhibited the activities of p38MAPK and JNK signal pathways in rats with myocardial I/R injury (P < 0.05). Additionally, p38MAPK and JNK blockers (SB239063 and SP600125, respectively) had an effect on rats same as that of PHC. Although Drp1 blocker (Mdivi-1) showed a similar cardioprotective effect (P < 0.05), it did not affect the expression of MAPKs and apoptosis-related proteins (P > 0.05). In addition, Bcl-2 blocker (ABT-737) caused a high expression of Drp1 and a low expression of Mfn1/2 (P < 0.05). PHC regulated mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provided cardioprotection in rats with myocardial I/R injury. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Activation of the Jnk signaling pathway by a dual-specificity phosphatase, JSP-1

    PubMed Central

    Shen, Yu; Luche, Ralf; Wei, Bo; Gordon, Marcia L.; Diltz, Curtis D.; Tonks, Nicholas K.

    2001-01-01

    The mitogen-activated protein kinases (MAPKs) are integral to the mechanisms by which cells respond to physiological stimuli, such as growth factors, hormones, and cytokines, and to a wide variety of environmental stresses. The MAPKs, which are stimulated by phosphorylation of a TXY motif in their activation loop, are components of signal transduction cascades in which sequential activation of protein kinases culminates in their activation and their subsequent phosphorylation of various effector proteins that mediate the physiological response. MAPKs are also subject to dephosphorylation and inactivation, both by enzymes that recognize the residues of the TXY motif independently and by dual specificity phosphatases, which dephosphroylate both Tyr and Ser/Thr residues. We report the identification and characterization of a novel dual specificity phosphatase. Contrary to expectation, this broadly expressed enzyme did not inactivate MAPKs in transient cotransfection assays but instead displayed the capacity to function as a selective activator of the MAPK Jnk, hence the name, Jnk Stimulatory Phosphatase-1 (JSP-1). This study illustrates a new aspect of the regulation of MAPK-dependent signal transduction and raises the possibility that JSP-1 may offer a different perspective to the study of various inflammatory and proliferative disorders associated with dysfunctional Jnk signaling. PMID:11717427

  11. Activation of the Jnk signaling pathway by a dual-specificity phosphatase, JSP-1.

    PubMed

    Shen, Y; Luche, R; Wei, B; Gordon, M L; Diltz, C D; Tonks, N K

    2001-11-20

    The mitogen-activated protein kinases (MAPKs) are integral to the mechanisms by which cells respond to physiological stimuli, such as growth factors, hormones, and cytokines, and to a wide variety of environmental stresses. The MAPKs, which are stimulated by phosphorylation of a TXY motif in their activation loop, are components of signal transduction cascades in which sequential activation of protein kinases culminates in their activation and their subsequent phosphorylation of various effector proteins that mediate the physiological response. MAPKs are also subject to dephosphorylation and inactivation, both by enzymes that recognize the residues of the TXY motif independently and by dual specificity phosphatases, which dephosphroylate both Tyr and Ser/Thr residues. We report the identification and characterization of a novel dual specificity phosphatase. Contrary to expectation, this broadly expressed enzyme did not inactivate MAPKs in transient cotransfection assays but instead displayed the capacity to function as a selective activator of the MAPK Jnk, hence the name, Jnk Stimulatory Phosphatase-1 (JSP-1). This study illustrates a new aspect of the regulation of MAPK-dependent signal transduction and raises the possibility that JSP-1 may offer a different perspective to the study of various inflammatory and proliferative disorders associated with dysfunctional Jnk signaling.

  12. Porphyromonas endodontalis lipopolysaccharides induce RANKL by mouse osteoblast in a way different from that of Escherichia coli lipopolysaccharide.

    PubMed

    Tang, Yin; Sun, Feifei; Li, Xiaoting; Zhou, Yuan; Yin, Shihai; Zhou, Xuedong

    2011-12-01

    Porphyromonas endodontalis lipopolysaccharide (LPS) has been shown to have a high positive rate in infected root canals and symptomatic apical periodontitis. It may play an integral role as a potent stimulator of inflammatory cytokines involved in apical lesions. The receptor activator of nuclear factor-κB ligand (RANKL) has been proven to be the key regulator of bone remodeling. This study investigated P. endodontalis LPS-induced RANKL production and LPS signaling in mouse osteoblasts. LPS-induced RANKL production in mouse osteoblast MC3T3-E1 cells was measured by Western blot and real-time polymerase chain reaction, and the Toll-like receptors (TLRs) were determined by the blocking test using anti-TLRs antibodies. In addition, specific inhibitors were used to analyze the intracellular signaling pathways. Escherichia coli LPS was used as the control. Both of the anti-TLR2 and anti-TLR4 antibodies significantly (P < .05) inhibited the expression of RANKL from osteoblasts stimulated with P. endodontalis LPS; only anti-TLR2 antibody had a significant (P < .05) inhibitory effect on E. coli LPS signaling. SP600125 (c-Jun N-terminal kinase [JNK] inhibitor) prevented the up-regulation of RANKL expression in P. endodontalis LPS-infected osteoblasts (P < .05). The inhibitory effect of wortmannin (phosphatidylinositol 3-kinase inhibitor) and PD98059 (mitogen-activated protein kinase [MAPK]/extracellular signal-regulated kinase [ERK] kinase-1/2 [MEK 1/2] inhibitor) were observed in E. coli LPS-treated mouse osteoblasts (P < .05). Results from this study showed that P. endodontalis LPS has the ability to promote the expression of RANKL in mouse osteoblasts, and this induction was mainly through the TLR2/4-JNK signaling pathway, a situation quite different from that of typical bacterial endotoxin (E. coli LPS). Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Protective effect of resveratrol against nigrostriatal pathway injury in striatum via JNK pathway.

    PubMed

    Li, Dan; Liu, Nan; Zhao, Liang; Tong, Lei; Kawano, Hitoshi; Yan, Hong-Jing; Li, Hong-Peng

    2017-01-01

    Nigrostriatal pathway injury is one of the traumatic brain injury models that usually lead to neurological dysfunction or neuron necrosis. Resveratrol-induced benefits have recently been demonstrated in several models of neuronal degeneration diseases. However, the protective properties of resveratrol against neurodegeneration have not been explored definitely. Thus, we employ the nigrostriatal pathway injury model to mimic the insults on the brain. Resveratrol decreased the p-ERK expression and increased the p-JNK expression compared to the DMSO group, but not alter the p38 MAPK proteins around the lesion site by Western blot. Prior to the injury, mice were infused with resveratrol intracerebroventricularly with or without JNK-IN-8, a specific c-JNK pathway inhibitor for JNK1, JNK2 and JNK4. The study assessed modified improved neurological function score (mNSS) and beam/walking test, the level of inflammatory cytokines IL-1β, IL-6 and TNF-α, and striatal expression of Bax and Bcl-2 proteins associated with neuronal apoptosis. The results revealed that resveratrol exerted a neuroprotective effect as shown by the improved mNSS and beam latency, anti-inflammatory effects as indicated by the decreased level of IL-1β, TNF-α and IL-6. Furthermore, resveratrol up-regulated the protein expression of p-JNK and Bcl-2, down-regulated the expression of Bax and the number of Fluoro-Jade C (FJC) positive neurons. However, these advantages of resveratrol were abolished by JNK-IN-8 treatment. Overall, we demonstrated that resveratrol treatment attenuates the nigrostriatal pathway injury-induced neuronal apoptosis and inflammation via activation of c-JNK signaling. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Febuxostat, an Inhibitor of Xanthine Oxidase, Suppresses Lipopolysaccharide-Induced MCP-1 Production via MAPK Phosphatase-1-Mediated Inactivation of JNK

    PubMed Central

    Nomura, Johji; Busso, Nathalie; Ives, Annette; Tsujimoto, Syunsuke; Tamura, Mizuho; So, Alexander; Yamanaka, Yoshihiro

    2013-01-01

    Excess reactive oxygen species (ROS) formation can trigger various pathological conditions such as inflammation, in which xanthine oxidase (XO) is one major enzymatic source of ROS. Although XO has been reported to play essential roles in inflammatory conditions, the molecular mechanisms underlying the involvement of XO in inflammatory pathways remain unclear. Febuxostat, a selective and potent inhibitor of XO, effectively inhibits not only the generation of uric acid but also the formation of ROS. In this study, therefore, we examined the effects of febuxostat on lipopolysaccharide (LPS)-mediated inflammatory responses. Here we show that febuxostat suppresses LPS-induced MCP-1 production and mRNA expression via activating MAPK phosphatase-1 (MKP-1) which, in turn, leads to dephosphorylation and inactivation of JNK in macrophages. Moreover, these effects of febuxostat are mediated by inhibiting XO-mediated intracellular ROS production. Taken together, our data suggest that XO mediates LPS-induced phosphorylation of JNK through ROS production and MKP-1 inactivation, leading to MCP-1 production in macrophages. These studies may bring new insights into the novel role of XO in regulating inflammatory process through MAPK phosphatase, and demonstrate the potential use of XO inhibitor in modulating the inflammatory processes. PMID:24086554

  15. HMGB1 induces an inflammatory response in endothelial cells via the RAGE-dependent endoplasmic reticulum stress pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luo, Ying; Li, Shu-Jun; Yang, Jian

    Highlights: •Mechanisms of inflammatory response induced by HMGB1 are incompletely understood. •We found that endoplasmic reticulum stress mediate the inflammatory response induced by HMGB1. •RAGE-mediated ERS pathways are involved in those processes. •We reported a new mechanism for HMGB1 induced inflammatory response. -- Abstract: The high mobility group 1B protein (HMGB1) mediates chronic inflammatory responses in endothelial cells, which play a critical role in atherosclerosis. However, the underlying mechanism is unknown. The goal of our study was to identify the effects of HMGB1 on the RAGE-induced inflammatory response in endothelial cells and test the possible involvement of the endoplasmic reticulummore » stress pathway. Our results showed that incubation of endothelial cells with HMGB1 (0.01–1 μg/ml) for 24 h induced a dose-dependent activation of endoplasmic reticulum stress transducers, as assessed by PERK and IRE1 protein expression. Moreover, HMGB1 also promoted nuclear translocation of ATF6. HMGB1-mediated ICAM-1 and P-selectin production was dramatically suppressed by PERK siRNA or IRE1 siRNA. However, non-targeting siRNA had no such effects. HMGB1-induced increases in ICAM-1 and P-selectin expression were also inhibited by a specific eIF2α inhibitor (salubrinal) and a specific JNK inhibitor (SP600125). Importantly, a blocking antibody specifically targeted against RAGE (anti-RAGE antibody) decreased ICAM-1, P-selectin and endoplasmic reticulum stress molecule (PERK, eIF2α, IRE1 and JNK) protein expression levels. Collectively, these novel findings suggest that HMGB1 promotes an inflammatory response by inducing the expression of ICAM-1 and P-selectin via RAGE-mediated stimulation of the endoplasmic reticulum stress pathway.« less

  16. Versican G3 Domain Modulates Breast Cancer Cell Apoptosis: A Mechanism for Breast Cancer Cell Response to Chemotherapy and EGFR Therapy

    PubMed Central

    Du, William Weidong; Yang, Burton B.; Yang, Bing L.; Deng, Zhaoqun; Fang, Ling; Shan, Sze Wan; Jeyapalan, Zina; Zhang, Yaou; Seth, Arun; Yee, Albert J.

    2011-01-01

    Overexpression of EGFR and versican has been reported in association with breast cancers. Considered oncogenic, these molecules may be attractive therapeutic targets. Possessing anti-apoptotic and drug resistant properties, overexpression of these molecules is accompanied by selective sensitization to the process of apoptosis. In this study, we exogenously expressed a versican G3 construct in breast cancer cell lines and analyzed the effects of G3 on cell viability in fetal bovine serum free conditioned media and evaluated the effects of apoptotic agent C2-ceramide, and chemotherapeutic agents including Docetaxel, Doxorubicin, and Epirubicin. Versican G3 domain enhanced tumor cell resistance to apoptosis when cultured in serum free medium, Doxorubicin, or Epirubicin by up-regulating pERK and GSK-3β (S9P). However, it could be prevented by selective EGFR inhibitor AG 1478 and selective MEK inhibitor PD 98059. Both AG 1478 and PD 98059 enhanced expression of pSAPK/JNK, while selective JNK inhibitor SP 600125 enhanced expression of GSK-3β (S9P). Versican G3 promoted cell apoptosis induced by C2-ceramide or Docetaxel by enhancing expression of pSAPK/JNK and decreasing expression of GSK-3β (S9P), an observation blocked by AG 1478 or SP 6000125. Inhibition of endogenous versican expression by siRNA or reduction of versican G3's expression by linking G3 with 3′UTR prevented G3 modulated cell apoptosis. The dual roles of G3 in modulating breast cancer cell resistance to chemotherapeutic agents may in part explain a potential mechanism for breast cancer cell resistance to chemotherapy and EGFR therapy. The apoptotic effects of chemotherapeutics depend upon the activation and balance of down stream signals in the EGFR pathway. GSK-3β (S9P) appears to function as a key checkpoint in this balance of apoptosis and anti-apoptosis. Investigation and potential consideration of targeting GSK-3β (S9P) merits further study. PMID:22096483

  17. Versican G3 domain modulates breast cancer cell apoptosis: a mechanism for breast cancer cell response to chemotherapy and EGFR therapy.

    PubMed

    Du, William Weidong; Yang, Burton B; Yang, Bing L; Deng, Zhaoqun; Fang, Ling; Shan, Sze Wan; Jeyapalan, Zina; Zhang, Yaou; Seth, Arun; Yee, Albert J

    2011-01-01

    Overexpression of EGFR and versican has been reported in association with breast cancers. Considered oncogenic, these molecules may be attractive therapeutic targets. Possessing anti-apoptotic and drug resistant properties, overexpression of these molecules is accompanied by selective sensitization to the process of apoptosis. In this study, we exogenously expressed a versican G3 construct in breast cancer cell lines and analyzed the effects of G3 on cell viability in fetal bovine serum free conditioned media and evaluated the effects of apoptotic agent C2-ceramide, and chemotherapeutic agents including Docetaxel, Doxorubicin, and Epirubicin. Versican G3 domain enhanced tumor cell resistance to apoptosis when cultured in serum free medium, Doxorubicin, or Epirubicin by up-regulating pERK and GSK-3β (S9P). However, it could be prevented by selective EGFR inhibitor AG 1478 and selective MEK inhibitor PD 98059. Both AG 1478 and PD 98059 enhanced expression of pSAPK/JNK, while selective JNK inhibitor SP 600125 enhanced expression of GSK-3β (S9P). Versican G3 promoted cell apoptosis induced by C2-ceramide or Docetaxel by enhancing expression of pSAPK/JNK and decreasing expression of GSK-3β (S9P), an observation blocked by AG 1478 or SP 6000125. Inhibition of endogenous versican expression by siRNA or reduction of versican G3's expression by linking G3 with 3'UTR prevented G3 modulated cell apoptosis. The dual roles of G3 in modulating breast cancer cell resistance to chemotherapeutic agents may in part explain a potential mechanism for breast cancer cell resistance to chemotherapy and EGFR therapy. The apoptotic effects of chemotherapeutics depend upon the activation and balance of down stream signals in the EGFR pathway. GSK-3β (S9P) appears to function as a key checkpoint in this balance of apoptosis and anti-apoptosis. Investigation and potential consideration of targeting GSK-3β (S9P) merits further study.

  18. 50 CFR 600.125 - Budgeting, funding, and accounting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Budgeting, funding, and accounting. 600... Councils § 600.125 Budgeting, funding, and accounting. Link to an amendment published at 75 FR 59150, Sept... Budgeting, funding, and accounting. (a) Council grant activities are governed by 15 CFR part 14 (Uniform...

  19. Pinus densiflora leaf essential oil induces apoptosis via ROS generation and activation of caspases in YD-8 human oral cancer cells

    PubMed Central

    JO, JEONG-RANG; PARK, JU SUNG; PARK, YU-KYOUNG; CHAE, YOUNG ZOO; LEE, GYU-HEE; PARK, GY-YOUNG; JANG, BYEONG-CHURL

    2012-01-01

    The leaf of Pinus (P.) densiflora, a pine tree widely distributed in Asian countries, has been used as a traditional medicine. In the present study, we investigated the anticancer activity of essential oil, extracted by steam distillation, from the leaf of P. densiflora in YD-8 human oral squamous cell carcinoma (OSCC) cells. Treatment of YD-8 cells with P. densiflora leaf essential oil (PLEO) at 60 μg/ml for 8 h strongly inhibited proliferation and survival and induced apoptosis. Notably, treatment with PLEO led to generation of ROS, activation of caspase-9, PARP cleavage, down-regulation of Bcl-2, and phosphorylation of ERK-1/2 and JNK-1/2 in YD-8 cells. Treatment with PLEO, however, did not affect the expression of Bax, XIAP and GRP78. Importantly, pharmacological inhibition studies demonstrated that treatment with vitamin E (an anti-oxidant) or z-VAD-fmk (a pan-caspase inhibitor), but not with PD98059 (an ERK-1/2 inhibitor) or SP600125 (a JNK-1/2 inhibitor), strongly suppressed PLEO-induced apoptosis in YD-8 cells and reduction of their survival. Vitamin E treatment further blocked activation of caspase-9 and Bcl-2 down-regulation induced by PLEO. Thus, these results demonstrate firstly that PLEO has anti-proliferative, anti-survival and pro-apoptotic effects on YD-8 cells and the effects are largely due to the ROS-dependent activation of caspases. PMID:22086183

  20. Pinus densiflora leaf essential oil induces apoptosis via ROS generation and activation of caspases in YD-8 human oral cancer cells.

    PubMed

    Jo, Jeong-Rang; Park, Ju Sung; Park, Yu-Kyoung; Chae, Young Zoo; Lee, Gyu-Hee; Park, Gy-Young; Jang, Byeong-Churl

    2012-04-01

    The leaf of Pinus (P.) densiflora, a pine tree widely distributed in Asian countries, has been used as a traditional medicine. In the present study, we investigated the anticancer activity of essential oil, extracted by steam distillation, from the leaf of P. densiflora in YD-8 human oral squamous cell carcinoma (OSCC) cells. Treatment of YD-8 cells with P. densiflora leaf essential oil (PLEO) at 60 µg/ml for 8 h strongly inhibited proliferation and survival and induced apoptosis. Notably, treatment with PLEO led to generation of ROS, activation of caspase-9, PARP cleavage, down-regulation of Bcl-2, and phosphorylation of ERK-1/2 and JNK-1/2 in YD-8 cells. Treatment with PLEO, however, did not affect the expression of Bax, XIAP and GRP78. Importantly, pharmaco-logical inhibition studies demonstrated that treatment with vitamin E (an anti-oxidant) or z-VAD-fmk (a pan-caspase inhibitor), but not with PD98059 (an ERK-1/2 inhibitor) or SP600125 (a JNK-1/2 inhibitor), strongly suppressed PLEO-induced apoptosis in YD-8 cells and reduction of their survival. Vitamin E treatment further blocked activation of caspase-9 and Bcl-2 down-regulation induced by PLEO. Thus, these results demonstrate firstly that PLEO has anti-proliferative, anti-survival and pro-apoptotic effects on YD-8 cells and the effects are largely due to the ROS-dependent activation of caspases.

  1. Effects of PTHrP on expression of MMP9 and MMP13 in sika deer antler chondrocytes.

    PubMed

    Wang, Shou-Tang; Gao, Ying-Jie; Duan, Cui-Cui; Li, Dang-Dang; Tian, Xue-Chao; Zhang, Qiao-Ling; Guo, Bin; Yue, Zhan-Peng

    2013-12-01

    Deer antlers are the only mammalian appendages to display an annual cycle of full regeneration. However, little is known about the molecular mechanisms of antler regeneration. Our previous study has demonstrated that parathyroid hormone-related peptide (PTHrP) can promote proliferation of antler chondrocytes and inhibit its differentiation, but the mechanism underlying such regulation is not fully understood. We have determined the role of PTHrP on the mRNA expression of matrix metalloproteinase-9 (MMP9) and MMP13 in the antler chondrocytes. The possible pathways that transduce PTHrP effects were examined. In situ hybridization showed that MMP9 and MMP13 were mainly localized in the dermal fibroblasts, perichondrium, and cartilage in the sika deer antler, of which MMP9 and MMP13 were highly expressed in the chondrocytes. Exogenous PTHrP could inhibit the expression of MMP9 and MMP13 in the antler chondrocytes. The inhibitory effect of PTHrP on MMP9 was abolished by JNK inhibitor, SP600125, while P38MAPK inhibitor SB203850 and PKC inhibitor GF109203X could rescue the inhibitory effect of PTHrP on MMP13. The results suggest that PTHrP can inhibit MMP9 expression by JNK signaling pathway and MMP13 expression by p38MAPK and PKC signaling pathways in the antler chondrocytes. Thus PTHrP is involved in the control of antler chondrocytes maturation and cartilage matrix degradation. © 2013 International Federation for Cell Biology.

  2. CFTR modulates RPS27 gene expression using chloride anion as signaling effector.

    PubMed

    Valdivieso, Ángel G; Mori, Consuelo; Clauzure, Mariángeles; Massip-Copiz, Macarena; Santa-Coloma, Tomás A

    2017-11-01

    In Cystic Fibrosis (CF), the impairment of the CFTR channel activity leads to a variety of alterations, including differential gene expression. However, the CFTR signaling mechanisms remain unclear. Recently, culturing IB3-1 CF cells under different intracellular Cl - concentrations ([Cl - ] i ), we observed several Cl - -dependent genes and further characterized one of them as RPS27. Thus, we hypothesized that Cl - might act as a signaling effector for CFTR signaling. Here, to test this idea, we study RPS27 expression in T84 cells modulating the CFTR activity by using CFTR inhibitors. First, we observed that incubation of T84 cells with increasing concentrations of the CFTR inhibitors CFTR(inh)-172 or GlyH-101 determined a progressive increase in the relative [Cl - ] i (using the Cl - fluorescent probe SPQ). The [Cl - ] i rise was concomitant with a dose-dependent down-regulation of RPS27. These results imply that CFTR inhibition produce Cl - accumulation and that RPS27 expression can be modulated by CFTR inhibition. Therefore, Cl - behaves as a signaling effector for CFTR in the modulation of RPS27 expression. In addition, the IL-1β receptor antagonist IL1RN or the JNK inhibitor SP600125, both restored the down-regulation of RPS27 induced by CFTRinh-172, implying a role of autocrine IL-1β and JNK signaling downstream of Cl - in RPS27 modulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Transcriptional regulation of an insulin-sensitizing adipokine adipolin/CTRP12 in adipocytes by Krüppel-like factor 15.

    PubMed

    Enomoto, Takashi; Ohashi, Koji; Shibata, Rei; Kambara, Takahiro; Uemura, Yusuke; Yuasa, Daisuke; Kataoka, Yoshiyuki; Miyabe, Megumi; Matsuo, Kazuhiro; Joki, Yusuke; Hayakawa, Satoko; Hiramatsu-Ito, Mizuho; Ito, Masanori; Murohara, Toyoaki; Ouchi, Noriyuki

    2013-01-01

    Obese states characterized by chronic inflammation are closely linked to the development of metabolic dysfunction. We identified adipolin/CTRP12 as an insulin-sensitizing and anti-inflammatory adipokine. Although obese conditions down-regulate adipolin expression, its molecular mechanism is largely unknown. Here we show that the transcriptional regulator Krüppel-like factor (KLF) 15 is involved in the regulation of adipolin expression in adipocytes. White adipose tissue from diet-induced obese (DIO) mice showed decreased expression of KLF9 and KLF15 among several KLFs, which was accompanied by reduced expression of adipolin. In cultured 3T3L1 adipocytes, treatment with TNFα significantly reduced the mRNA levels of KLF9, KLF15 and adipolin. Adenovirus-mediated overexpression of KLF15 but not KLF9 reversed TNFα-induced reduction of adipolin expression in adipocytes. Conversely, gene targeting ablation of KLF15 attenuated adipolin expression in adipocytes. Expression of KLF15 but not KLF9 enhanced the promoter activity of adipolin in HEK293 cells. Pretreatment of 3T3L1 adipocytes with the JNK inhibitor SP600125, but not p38 MAPK inhibitor SB203580 blocked the inhibitory effects of TNFα on adipolin and KLF15 expression. These data suggest that adipose inflammation under conditions of obesity suppresses adipolin expression via JNK-dependent down-regulation of KLF15 in adipocytes.

  4. Transcriptional Regulation of an Insulin-Sensitizing Adipokine Adipolin/CTRP12 in Adipocytes by Krüppel-Like Factor 15

    PubMed Central

    Enomoto, Takashi; Ohashi, Koji; Shibata, Rei; Kambara, Takahiro; Uemura, Yusuke; Yuasa, Daisuke; Kataoka, Yoshiyuki; Miyabe, Megumi; Matsuo, Kazuhiro; Joki, Yusuke; Hayakawa, Satoko; Hiramatsu-Ito, Mizuho; Ito, Masanori; Murohara, Toyoaki; Ouchi, Noriyuki

    2013-01-01

    Obese states characterized by chronic inflammation are closely linked to the development of metabolic dysfunction. We identified adipolin/CTRP12 as an insulin-sensitizing and anti-inflammatory adipokine. Although obese conditions down-regulate adipolin expression, its molecular mechanism is largely unknown. Here we show that the transcriptional regulator Krüppel-like factor (KLF) 15 is involved in the regulation of adipolin expression in adipocytes. White adipose tissue from diet-induced obese (DIO) mice showed decreased expression of KLF9 and KLF15 among several KLFs, which was accompanied by reduced expression of adipolin. In cultured 3T3L1 adipocytes, treatment with TNFα significantly reduced the mRNA levels of KLF9, KLF15 and adipolin. Adenovirus-mediated overexpression of KLF15 but not KLF9 reversed TNFα-induced reduction of adipolin expression in adipocytes. Conversely, gene targeting ablation of KLF15 attenuated adipolin expression in adipocytes. Expression of KLF15 but not KLF9 enhanced the promoter activity of adipolin in HEK293 cells. Pretreatment of 3T3L1 adipocytes with the JNK inhibitor SP600125, but not p38 MAPK inhibitor SB203580 blocked the inhibitory effects of TNFα on adipolin and KLF15 expression. These data suggest that adipose inflammation under conditions of obesity suppresses adipolin expression via JNK-dependent down-regulation of KLF15 in adipocytes. PMID:24358263

  5. Autophagy blockade sensitizes the anticancer activity of CA-4 via JNK-Bcl-2 pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Yangling; Luo, Peihua; Wang, Jincheng

    Combretastatin A-4 (CA-4) has already entered clinical trials of solid tumors over ten years. However, the limited anticancer activity and dose-dependent toxicity restrict its clinical application. Here, we offered convincing evidence that CA-4 induced autophagy in various cancer cells, which was demonstrated by acridine orange staining of intracellular acidic vesicles, the degradation of p62, the conversion of LC3-I to LC3-II and GFP-LC3 punctate fluorescence. Interestingly, CA-4-mediated apoptotic cell death was further potentiated by pretreatment with autophagy inhibitors (3-methyladenine and bafilomycin A1) or small interfering RNAs against the autophagic genes (Atg5 and Beclin 1). The enhanced anticancer activity of CA-4 andmore » 3-MA was further confirmed in the SGC-7901 xenograft tumor model. These findings suggested that CA-4-elicited autophagic response played a protective role that impeded the eventual cell death while autophagy inhibition was expected to improve chemotherapeutic efficacy of CA-4. Meanwhile, CA-4 treatment led to phosphorylation/activation of JNK and JNK-dependent phosphorylation of Bcl-2. Importantly, JNK inhibitor or JNK siRNA inhibited autophagy but promoted CA-4-induced apoptosis, indicating a key requirement of JNK-Bcl-2 pathway in the activation of autophagy by CA-4. We also identified that pretreatment of Bcl-2 inhibitor (ABT-737) could significantly enhance anticancer activity of CA-4 due to inhibition of autophagy. Taken together, our data suggested that the JNK-Bcl-2 pathway was considered as the critical regulator of CA-4-induced protective autophagy and a potential drug target for chemotherapeutic combination. - Highlights: • Autophagy inhibition could be a potential for combretastatin A-4 antitumor efficacy. • The JNK-Bcl-2 pathway plays a critical role in CA-4-induced autophagy. • ABT-737 enhances CA-4 anticancer activity due to inhibition of autophagy.« less

  6. Down-Regulation by Resveratrol of Basic Fibroblast Growth Factor-Stimulated Osteoprotegerin Synthesis through Suppression of Akt in Osteoblasts

    PubMed Central

    Kuroyanagi, Gen; Otsuka, Takanobu; Yamamoto, Naohiro; Matsushima-Nishiwaki, Rie; Nakakami, Akira; Mizutani, Jun; Kozawa, Osamu; Tokuda, Haruhiko

    2014-01-01

    It is firmly established that resveratrol, a natural food compound abundantly found in grape skins and red wine, has beneficial properties for human health. In the present study, we investigated the effect of basic fibroblast growth factor (FGF-2) on osteoprotegerin (OPG) synthesis in osteoblast-like MC3T3-E1 cells and whether resveratrol affects the OPG synthesis. FGF-2 stimulated both the OPG release and the expression of OPG mRNA. Resveratrol significantly suppressed the FGF-2-stimulated OPG release and the mRNA levels of OPG. SRT1720, an activator of SIRT1, reduced the FGF-2-induced OPG release and the OPG mRNA expression. PD98059, an inhibitor of upstream kinase activating p44/p42 mitogen-activated protein (MAP) kinase, had little effect on the FGF-2-stimulated OPG release. On the other hand, SB203580, an inhibitor of p38 MAP kinase, SP600125, an inhibitor of stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), and Akt inhibitor suppressed the OPG release induced by FGF-2. Resveratrol failed to affect the FGF-2-induced phosphorylation of p44/p42 MAP kinase, p38 MAP kinase or SAPK/JNK. The phosphorylation of Akt induced by FGF-2 was significantly suppressed by resveratrol or SRT1720. These findings strongly suggest that resveratrol down-regulates FGF-2-stimulated OPG synthesis through the suppression of the Akt pathway in osteoblasts and that the inhibitory effect of resveratrol is mediated at least in part by SIRT1 activation. PMID:25290095

  7. JNK-1 Inhibition Leads to Antitumor Activity in Ovarian Cancer

    PubMed Central

    Vivas-Mejia, Pablo; Benito, Juliana Maria; Fernandez, Ariel; Han, Hee-Dong; Mangala, Lingegowda; Rodriguez-Aguayo, Cristian; Chavez-Reyes, Arturo; Lin, Yvonne G.; Nick, Alpa M.; Stone, Rebecca L.; Kim, Hye Sun; Claret, Francois-Xavier; Bornmann, William; Hennessy, Bryan TJ.; Sanguino, Angela; Peng, Zhengong; Sood, Anil K.; Lopez-Berestein, Gabriel

    2011-01-01

    Purpose To demonstrate the functional, clinical and biological significance of JNK-1 in ovarian carcinoma. Experimental Design Analysis of the impact of JNK on 116 epithelial ovarian cancers was conducted. The role of JNK in vitro and in experimental models of ovarian cancer was assessed. We studied the role of WBZ_4, a novel JNK inhibitor redesigned from imatinib based on targeting wrapping defects, in cell lines and in experimental models of ovarian cancer. Results We found a significant association of pJNK with progression free survival in the 116 epithelial ovarian cancers obtained at primary debulking therapy. WBZ_4 led to cell growth inhibition and increased apoptosis in a dose dependent fashion in four ovarian cancer cell lines. In vivo, while imatinib had no effect on tumor growth, WBZ_4 inhibited tumor growth in orthotopic murine models of ovarian cancer. The anti-tumor effect was further increased in combination with docetaxel. Silencing of JNK-1 with systemically administered siRNA led to significantly reduced tumor weights as compared to non-silencing siRNA controls, indicating that indeed the antitumor effects observed were due to JNK-1 inhibition. Conclusions These studies identify JNK-1 as an attractive therapeutic target in ovarian carcinoma and that the re-designed WBZ_4 compound should be considered for further clinical development. PMID:20028751

  8. Zanthoxylum fruit extract from Japanese pepper promotes autophagic cell death in cancer cells.

    PubMed

    Nozaki, Reo; Kono, Toru; Bochimoto, Hiroki; Watanabe, Tsuyoshi; Oketani, Kaori; Sakamaki, Yuichi; Okubo, Naoto; Nakagawa, Koji; Takeda, Hiroshi

    2016-10-25

    Zanthoxylum fruit, obtained from the Japanese pepper plant (Zanthoxylum piperitum De Candolle), and its extract (Zanthoxylum fruit extract, ZFE) have multiple physiological activities (e.g., antiviral activity). However, the potential anticancer activity of ZFE has not been fully examined. In this study, we investigated the ability of ZFE to induce autophagic cell death (ACD). ZFE caused remarkable autophagy-like cytoplasmic vacuolization, inhibited cell proliferation, and ultimately induced cell death in the human cancer cell lines DLD-1, HepG2, and Caco-2, but not in A549, MCF-7, or WiDr cells. ZFE increased the level of LC3-II protein, a marker of autophagy. Knockdown of ATG5 using siRNA inhibited ZFE-induced cytoplasmic vacuolization and cell death. Moreover, in cancer cells that could be induced to undergo cell death by ZFE, the extract increased the phosphorylation of c-Jun N-terminal kinase (JNK), and the JNK inhibitor SP600125 attenuated both vacuolization and cell death. Based on morphology and expression of marker proteins, ZFE-induced cell death was neither apoptosis nor necrosis. Normal intestinal cells were not affected by ZFE. Taken together, our findings show that ZFE induces JNK-dependent ACD, which appears to be the main mechanism underlying its anticancer activity, suggesting a promising starting point for anticancer drug development.

  9. 1-Methoxy-agroclavine from Penicillium sp. WC75209, a novel inhibitor of the Lck tyrosine kinase.

    PubMed

    Padmanabha, R; Shu, Y Z; Cook, L S; Veitch, J A; Donovan, M; Lowe, S; Huang, S; Pirnik, D; Manly, S P

    1998-03-17

    A high-throughput screen was developed and implemented to identify inhibitors of the Lck tyrosine kinase. This report describes the identification of a specific inhibitor of this enzyme from the solid fermentation culture of the Penicillium sp., WC75209. The active compound was isolated and structurally characterized as 1-methoxy-5R, 10S-agroclavine, a new member of the ergot alkaloid family.

  10. ROS-dependent activation of JNK converts p53 into an efficient inhibitor of oncogenes leading to robust apoptosis

    PubMed Central

    Shi, Y; Nikulenkov, F; Zawacka-Pankau, J; Li, H; Gabdoulline, R; Xu, J; Eriksson, S; Hedström, E; Issaeva, N; Kel, A; Arnér, E S J; Selivanova, G

    2014-01-01

    Rescue of the p53 tumor suppressor is an attractive cancer therapy approach. However, pharmacologically activated p53 can induce diverse responses ranging from cell death to growth arrest and DNA repair, which limits the efficient application of p53-reactivating drugs in clinic. Elucidation of the molecular mechanisms defining the biological outcome upon p53 activation remains a grand challenge in the p53 field. Here, we report that concurrent pharmacological activation of p53 and inhibition of thioredoxin reductase followed by generation of reactive oxygen species (ROS), result in the synthetic lethality in cancer cells. ROS promote the activation of c-Jun N-terminal kinase (JNK) and DNA damage response, which establishes a positive feedback loop with p53. This converts the p53-induced growth arrest/senescence to apoptosis. We identified several survival oncogenes inhibited by p53 in JNK-dependent manner, including Mcl1, PI3K, eIF4E, as well as p53 inhibitors Wip1 and MdmX. Further, we show that Wip1 is one of the crucial executors downstream of JNK whose ablation confers the enhanced and sustained p53 transcriptional response contributing to cell death. Our study provides novel insights for manipulating p53 response in a controlled way. Further, our results may enable new pharmacological strategy to exploit abnormally high ROS level, often linked with higher aggressiveness in cancer, to selectively kill cancer cells upon pharmacological reactivation of p53. PMID:24413150

  11. Production of reactive oxygen species by withaferin A causes loss of type collagen expression and COX-2 expression through the PI3K/Akt, p38, and JNK pathways in rabbit articular chondrocytes.

    PubMed

    Yu, Seon-Mi; Kim, Song-Ja

    2013-11-01

    Withaferin A (WFA) is a major chemical constituent of Withania somnifera, also known as Indian ginseng. Many recent reports have provided evidence of its anti-tumor, anti-inflammation, anti-oxidant, and immune modulatory activities. Although the compound appears to have a large number of effects, its defined mechanisms of action have not yet been determined. We investigated the effects of WFA on loss of type collagen expression and inflammation in rabbit articular chondrocytes. WFA increased the production of reactive oxygen species, suggesting the induction of oxidative stress, in a dose-dependent manner. Also, we confirmed that WFA causes loss of type collagen expression and inflammation as determined by a decrease of type II collagen expression and an increase of cyclooxygenase-2 (COX-2) expression via western blot analysis in a dose- and time- dependent manner. WFA also reduced the synthesis of sulfated proteoglycan via Alcian blue staining and caused the synthesis of prostaglandin E2 (PGE2) via assay kit in dose- and time-dependent manners. Treatment with N-acetyl-L-cysteine (NAC), an antioxidant, inhibited WFA-induced loss of type II collagen expression and increase in COX-2 expression, accompanied by inhibition of reactive oxygen species production. WFA increased phosphorylation of both Akt and p38. Inhibition of PI3K/Akt, p38, and JNK with LY294002 (LY), SB203580 (SB), or SP600125 (SP) in WFA-treated cells rescued the expression of type II collagen and suppressed the expression of COX-2. These results demonstrate that WFA induces loss of type collagen expression and inflammation via PI3K/Akt, p38, and JNK by generating reactive oxygen species in rabbit articular chondrocytes. © 2013 Published by Elsevier Inc.

  12. Inhibition of xyloglucanase from an alkalothermophilic Thermomonospora sp. by a peptidic aspartic protease inhibitor from Penicillium sp. VM24.

    PubMed

    Menon, Vishnu; Rao, Mala

    2012-11-01

    A bifunctional inhibitor from Penicillium sp VM24 causing inactivation of xyloglucanase from Thermomonospora sp and an aspartic protease from Aspergillus saitoi was identified. Steady state kinetics studies of xyloglucanase and the inhibitor revealed an irreversible, non-competitive, two-step inhibition mechanism with IC(50) and K(i) values of 780 and 500nM respectively. The interaction of o-phthalaldehyde (OPTA)-labeled xyloglucanase with the inhibitor revealed that the inhibitor binds to the active site of the enzyme. Far- and near-UV spectrophotometric analysis suggests that the conformational changes induced in xyloglucanase by the inhibitor may be due to irreversible denaturation of enzyme. The bifunctional inhibitor may have potential as a biocontrol agent for the protection of plants against phytopathogenic fungi. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Rhodanine derivatives as inhibitors of JSP-1.

    PubMed

    Cutshall, Neil S; O'Day, Christine; Prezhdo, Marina

    2005-07-15

    Dual-specificity phosphatases (DSPs) are a subclass within the protein tyrosine phosphatase family (PTPs). A series of rhodanine-based inhibitors was synthesized and shown to be novel, potent, and selective inhibitors against the DSP family member JNK-stimulating phosphatase-1 (JSP-1). Compounds of this class may be useful for the treatment of inflammatory and proliferative disorders.

  14. The suppression of bromodomain and extra‐terminal domain inhibits vascular inflammation by blocking NF‐κB and MAPK activation

    PubMed Central

    Huang, Mingcheng; Zeng, Shan; Zou, Yaoyao; Shi, Maohua; Qiu, Qian; Xiao, Youjun; Chen, Guoqiang; Yang, Xiuyan; Liang, Liuqin

    2016-01-01

    Background and Purpose There is increasing evidence indicating that bromodomain and extra‐terminal domain (BET) proteins play a critical role in the regulation of immune and inflammatory responses; however, their contribution to vascular inflammation has not yet been elucidated. In this study, we investigated the effect of inhibiting BET bromodomain on vascular inflammation and the underlying mechanisms. Experimental Approach HUVECs were isolated from fresh umbilical cords. JQ1, a specific BET bromodomain inhibitor, and Brd shRNA were used to evaluate the regulation of the BET proteins in vascular inflammation. Leukocyte adhesion to HUVECs was measure by an adhesion assay. Western blot or immunohistochemical analysis was used to detect the protein expression. Real‐time PCR was used to evaluate mRNA expression. Leukocyte accumulation in vivo was determined by an acute lung inflammation model. Key Results BET bromodomain inhibition suppressed the expression of adhesion molecules induced by TNF‐α‐ or LPS, including ICAM‐1, VCAM‐1 and E‐selectin, and inhibited leukocyte adhesion to activated HUVEC monolayers. Treatment with JQ1 also attenuated the LPS‐induced accumulation of leukocytes and expression of endothelial adhesion molecules in the acute lung inflammation model in vivo. Furthermore, BET bromodomain inhibition reduced the activity of p38 and JNK MAPKs and NF‐κB in TNF‐α‐stimulated HUVECs. TNF‐α‐induced NF‐κB activation was also blocked by inhibitors of p38 (SB203580) or JNK (SP600125). Conclusions and Implications BET bromodomain is important for regulating endothelial inflammation. Strategies targeting endothelial BET bromodomain may provide a new therapeutic approach for controlling inflammatory‐related diseases. PMID:27774624

  15. The coffee diterpene kahweol suppresses the cell proliferation by inducing cyclin D1 proteasomal degradation via ERK1/2, JNK and GKS3β-dependent threonine-286 phosphorylation in human colorectal cancer cells.

    PubMed

    Park, Gwang Hun; Song, Hun Min; Jeong, Jin Boo

    2016-09-01

    Kahweol as a coffee-specific diterpene has been reported to exert anti-cancer properties. However, the mechanism responsible for the anti-cancer effects of kahweol is not fully understood. The main aim of this investigation was to determine the effect of kahweol on cell proliferation and the possible mechanisms in human colorectal cancer cells. Kahweol inhibited markedly the proliferation of human colorectal cancer cell lines such as HCT116, SW480. Kahweol decreased cyclin D1 protein level in HCT116 and SW480 cells. Contrast to protein levels, cyclin D1 mRNA level and promoter activity did not be changed by kahweol treatment. MG132 treatment attenuated kahweol-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in kahweol-treated cells. Kahweol increased phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine attenuated cyclin D1 degradation by kahweol. Inhibition of ERK1/2 by PD98059, JNK by SP600125 or GSK3β by LiCl suppressed cyclin D1 phosphorylation and downregulation by kahweol. Furthermore, the inhibition of nuclear export by LMB attenuated cyclin D1 degradation by kahweol. In conclusion, kahweol-mediated cyclin D1 degradation may contribute to the inhibition of the proliferation in human colorectal cancer cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. JNK3-Mediated Apoptotic Cell Death in Primary Dopaminergic Neurons

    PubMed Central

    Choi, Won-Seok; Klintworth, Heather M.; Xia, Zhengui

    2012-01-01

    Investigation of mechanisms responsible for dopaminergic neuron death is critical for understanding the pathogenesis of Parkinson’s disease, yet this is often quite challenging technically. Here, we describe detailed methods for culturing primary mesencephalic dopaminergic neurons and examining the activation of c-Jun N-terminal protein Kinase (JNK) in these cultures. We utilized immunocytochemistry and computerized analysis to quantify the number of surviving dopaminergic neurons and JNK activation in dopaminergic neurons. TUNEL staining was used to quantify apoptotic cell death. siRNA was used to specifically inhibit JNK3, the neural specific isoform of JNK. Our data implicate the activation of JNK3 in rotenone-induced dopaminergic neuron apoptosis. PMID:21815073

  17. Identification of Chemical Inhibitors of β-Catenin-Driven Liver Tumorigenesis in Zebrafish

    PubMed Central

    Evason, Kimberley J.; Francisco, Macrina T.; Juric, Vladislava; Balakrishnan, Sanjeev; Lopez Pazmino, Maria del Pilar; Gordan, John D.; Kakar, Sanjay; Spitsbergen, Jan; Goga, Andrei; Stainier, Didier Y. R.

    2015-01-01

    Hepatocellular carcinoma (HCC) is one of the most lethal human cancers. The search for targeted treatments has been hampered by the lack of relevant animal models for the genetically diverse subsets of HCC, including the 20-40% of HCCs that are defined by activating mutations in the gene encoding β-catenin. To address this chemotherapeutic challenge, we created and characterized transgenic zebrafish expressing hepatocyte-specific activated β-catenin. By 2 months post fertilization (mpf), 33% of transgenic zebrafish developed HCC in their livers, and 78% and 80% of transgenic zebrafish showed HCC at 6 and 12 mpf, respectively. As expected for a malignant process, transgenic zebrafish showed significantly decreased mean adult survival compared to non-transgenic control siblings. Using this novel transgenic model, we screened for druggable pathways that mediate β-catenin-induced liver growth and identified two c-Jun N-terminal kinase (JNK) inhibitors and two antidepressants (one tricyclic antidepressant, amitriptyline, and one selective serotonin reuptake inhibitor) that suppressed this phenotype. We further found that activated β-catenin was associated with JNK pathway hyperactivation in zebrafish and in human HCC. In zebrafish larvae, JNK inhibition decreased liver size specifically in the presence of activated β-catenin. The β-catenin-specific growth-inhibitory effect of targeting JNK was conserved in human liver cancer cells. Our other class of hits, antidepressants, has been used in patient treatment for decades, raising the exciting possibility that these drugs could potentially be repurposed for cancer treatment. In support of this proposal, we found that amitriptyline decreased tumor burden in a mouse HCC model. Our studies implicate JNK inhibitors and antidepressants as potential therapeutics for β-catenin-induced liver tumors. PMID:26134322

  18. Potential down-regulation of salivary gland AQP5 by LPS via cross-coupling of NF-kappaB and p-c-Jun/c-Fos.

    PubMed

    Yao, Chenjuan; Purwanti, Nunuk; Karabasil, Mileva Ratko; Azlina, Ahmad; Javkhlan, Purevjav; Hasegawa, Takahiro; Akamatsu, Tetsuya; Hosoi, Toru; Ozawa, Koichiro; Hosoi, Kazuo

    2010-08-01

    The mRNA and protein levels of aquaporin (AQP)5 in the parotid gland were found to be potentially decreased by lipopolysaccharide (LPS) in vivo in C3H/HeN mice, but only weakly in C3H/HeJ, a TLR4 mutant mouse strain. In the LPS-injected mice, pilocarpine-stimulated saliva production was reduced by more than 50%. In a tissue culture system, the LPS-induced decrease in the AQP5 mRNA level was blocked completely by pyrrolidine dithiocarbamate, MG132, tyrphostin AG126, SP600125, and partially by SB203580, which are inhibitors for IkappaB kinase, 26S proteasome, ERK1/2, JNK, and p38 MAPK, respectively. In contrast, the expression of AQP1 mRNA was down-regulated by LPS and such down-regulation was blocked only by SP600125. The transcription factors NF-kappaB (p65 subunit), p-c-Jun, and c-Fos were increased by LPS given in vivo, whereas the protein-binding activities of the parotid gland extract toward the sequences for NF-kappaB but not AP-1-responsive elements present at the promoter region of the AQP5 gene were increased by LPS injection. Co-immunoprecipitation by using antibody columns suggested the physical association of the three transcription factors. These results suggest that LPS-induced potential down-regulation of expression of AQP5 mRNA in the parotid gland is mediated via a complex(es) of these two classes of transcription factors, NF-kappaB and p-c-Jun/c-Fos.

  19. LW-214, a newly synthesized flavonoid, induces intrinsic apoptosis pathway by down-regulating Trx-1 in MCF-7 human breast cells.

    PubMed

    Pan, Di; Li, Wei; Miao, Hanchi; Yao, Jing; Li, Zhiyu; Wei, Libin; Zhao, Li; Guo, Qinglong

    2014-02-15

    In this study, the anticancer effect of LW-214, a newly synthesized flavonoid, against MCF-7 human breast cancer cells and the underlying mechanisms were investigated. LW-214 triggered the mitochondrial apoptotic pathway by increasing Bax/Bcl-2 ratio, loss of mitochondrial membrane potential (ΔΨm) and caspase-9 activation, degradation of poly (ADP-ribose) polymerase (PARP), cytochrome c (Cyt c) release and apoptosis-inducing factor (AIF) transposition. Further research revealed that both the reactive oxygen species (ROS) generation and the apoptosis signal regulating kinase 1 (ASK1) activation by LW-214 were induced by down-regulating the thioredoxin-1 (Trx-1) expression. The ROS elevation and ASK1 activation induced a sustained phosphorylation of c-Jun N-terminal kinase (JNK), while SP600125, as known as JNK inhibitor, almost reversed LW-214-induced apoptosis in MCF-7 cells. Overexpression of Trx-1 in MCF-7 cells attenuated LW-214-mediated apoptosis as well as the JNK activation and reversed the expression of mitochondrial apoptosis-related protein. Accordingly, the in vivo study showed that LW-214 exhibited a potential antitumor effect in BALB/c species mice inoculated MCF-7 tumor with low systemic toxicity, and the mechanism was the same as in vitro study. Taken together, these findings indicated that LW-214 may down-regulated Trx-1 function, causing intracellular ROS generation and releasing the ASK1, and lead to JNK activation, which consequently induced the mitochondrial apoptosis in vitro and in vivo. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Transgenerational cell fate profiling

    PubMed Central

    Jemaà, Mohamed; Galluzzi, Lorenzo; Kepp, Oliver; Castedo, Maria; Rello-Varona, Santiago; Vitale, Ilio; Kroemer, Guido

    2013-01-01

    The illicit generation of tetraploid cells constitutes a prominent driver of oncogenesis, as it often precedes the development of aneuploidy and genomic instability. In addition, tetraploid (pre-)malignant cells display an elevated resistance against radio- and chemotherapy. Here, we report a strategy to preferentially kill tetraploid tumor cells based on the broad-spectrum kinase inhibitor SP600125. Live videomicroscopy revealed that SP600125 affects the execution of mitosis, impedes proper cell division and/or activates apoptosis in near-to-tetraploid, though less so in parental, cancer cells. We propose a novel graphical model to quantify the differential response of diploid and tetraploid cells to mitotic perturbators, including SP600125, which we baptized “transgenerational cell fate profiling.” We speculate that this representation constitutes a valid alternative to classical “single-cell fate” and “genealogical” profiling and, hence, may facilitate the analysis of cell fate within a heterogeneous population as well as the visual examination of cell cycle alterations. PMID:23255111

  1. Tentacle extract from the jellyfish Cyanea capillata increases proliferation and migration of human umbilical vein endothelial cells through the ERK1/2 signaling pathway

    PubMed Central

    Wang, Qianqian; Zhang, Hui; Liu, Guoyan; He, Qian; Zhang, Liming

    2017-01-01

    Wound healing is a complex biological process, and current research finds that jellyfish have a great capacity for promoting growth and healing. However, the underlying mechanisms remain unclear. Thus, this study was conducted to investigate the molecular mechanisms and effects of a tentacle extract (TE) from the jellyfish Cyanea capillata (C. capillata) on cell proliferation and migration in human umbilical vein endothelial cells (HUVECs). First, our results showed that TE at the concentration of 1 μg/ml could promote cell proliferation over various durations, induce a transition of the cells from the G1-phase to the S/G2-phase of the cell cycle, and increase the expression of cell cycle proteins (CyclinB1 and CyclinD1). Second, we found that TE could activate the PI3K/Akt, ERK1/2 and JNK MAPK signaling pathways but not the NF-κB signaling pathway or the apoptosis signaling cascade. Finally, we demonstrated that the TE-induced expression of cell cycle proteins was decreased by ERK1/2 inhibitor PD98059 but not by PI3K inhibitor LY294002 or JNK inhibitor SP600125. Similarly, the TE-enhanced migration ability of HUVECs was also markedly attenuated by PD98059. Taken together, our findings indicate that TE-induced proliferation and migration in HUVECs mainly occurred through the ERK1/2 MAPK signaling pathway. These results are instructively important for further research on the isolation and purification of growth-promoting factors from C. capillata and are hopeful as a means to improve human wound repair in unfavorable conditions. PMID:29261770

  2. Tentacle extract from the jellyfish Cyanea capillata increases proliferation and migration of human umbilical vein endothelial cells through the ERK1/2 signaling pathway.

    PubMed

    Wang, Beilei; Liu, Dan; Wang, Chao; Wang, Qianqian; Zhang, Hui; Liu, Guoyan; He, Qian; Zhang, Liming

    2017-01-01

    Wound healing is a complex biological process, and current research finds that jellyfish have a great capacity for promoting growth and healing. However, the underlying mechanisms remain unclear. Thus, this study was conducted to investigate the molecular mechanisms and effects of a tentacle extract (TE) from the jellyfish Cyanea capillata (C. capillata) on cell proliferation and migration in human umbilical vein endothelial cells (HUVECs). First, our results showed that TE at the concentration of 1 μg/ml could promote cell proliferation over various durations, induce a transition of the cells from the G1-phase to the S/G2-phase of the cell cycle, and increase the expression of cell cycle proteins (CyclinB1 and CyclinD1). Second, we found that TE could activate the PI3K/Akt, ERK1/2 and JNK MAPK signaling pathways but not the NF-κB signaling pathway or the apoptosis signaling cascade. Finally, we demonstrated that the TE-induced expression of cell cycle proteins was decreased by ERK1/2 inhibitor PD98059 but not by PI3K inhibitor LY294002 or JNK inhibitor SP600125. Similarly, the TE-enhanced migration ability of HUVECs was also markedly attenuated by PD98059. Taken together, our findings indicate that TE-induced proliferation and migration in HUVECs mainly occurred through the ERK1/2 MAPK signaling pathway. These results are instructively important for further research on the isolation and purification of growth-promoting factors from C. capillata and are hopeful as a means to improve human wound repair in unfavorable conditions.

  3. Fenofibrate inhibits aldosterone-induced apoptosis in adult rat ventricular myocytes via stress-activated kinase-dependent mechanisms

    PubMed Central

    De Silva, Deepa S.; Wilson, Richard M.; Hutchinson, Christoph; Ip, Peter C.; Garcia, Anthony G.; Lancel, Steve; Ito, Masa; Pimentel, David R.; Sam, Flora

    2009-01-01

    Aldosterone induces extracellular signal-regulated kinase (ERK)-dependent cardiac remodeling. Fenofibrate improves cardiac remodeling in adult rat ventricular myocytes (ARVM) partly via inhibition of aldosterone-induced ERK1/2 phosphorylation and inhibition of matrix metalloproteinases. We sought to determine whether aldosterone caused apoptosis in cultured ARVM and whether fenofibrate ameliorated the apoptosis. Aldosterone (1 μM) induced apoptosis by increasing terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL)-positive nuclei in ARVM. Spironolactone (100 nM), an aldosterone receptor antagonist, but not RU-486, a glucocorticoid receptor, inhibited aldosterone-mediated apoptosis, indicating that the mineralocorticoid receptor (MR) plays a role. SP-600125 (3 μM)—a selective inhibitor of c-Jun NH2-terminal kinase (JNK)—inhibited aldosterone-induced apoptosis in ARVM. Although aldosterone increased the expression of both stress-activated protein kinases, pretreatment with fenofibrate (10 μM) decreased aldosterone-mediated apoptosis by inhibiting only JNK phosphorylation and the aldosterone-induced increases in Bax, p53, and cleaved caspase-3 and decreases in Bcl-2 protein expression in ARVM. In vivo studies demonstrated that chronic fenofibrate (100 mg·kg body wt−1·day−1) inhibited myocardial Bax and increased Bcl-2 expression in aldosterone-induced cardiac hypertrophy. Similarly, eplerenone, a selective MR inhibitor, used in chronic pressure-overload ascending aortic constriction inhibited myocardial Bax expression but had no effect on Bcl-2 expression. Therefore, involvement of JNK MAPK-dependent mitochondrial death pathway mediates ARVM aldosterone-induced apoptosis and is inhibited by fenofibrate, a peroxisome proliferator-activated receptor (PPAR)α ligand. Fenofibrate mediates beneficial effects in cardiac remodeling by inhibiting programmed cell death and the stress-activated kinases. PMID:19395558

  4. Actinobacillus actinomycetemcomitans Y4 capsular polysaccharide induces IL-1β mRNA expression through the JNK pathway in differentiated THP-1 cells

    PubMed Central

    Iwata, T; Mitani, A; Ishihara, Y; Tanaka, S; Yamamoto, G; Kikuchi, T; Naganawa, T; Matsumura, Y; Suga, T; Koide, M; Sobue, T; Suzuki, T; Noguchi, T

    2005-01-01

    Capsular polysaccharide from Actinobacillus actinomycetemcomitans Y4 (Y4 CP) induces bone resorption in a mouse organ culture system and osteoclast formation in mouse bone marrow cultures, as reported in previous studies. We also found that Y4 CP inhibits the release of interleukin (IL)-6 and IL-8 from human gingival fibroblast (HGF). Thus Y4 CP induces various responses in localized tissue and leads to the secretion of several cytokines. However, the effects of Y4 CP on human monocytes/macrophages are still unclear. In this study, THP-1 cells, which are a human monocytic cell line, were stimulated with Y4 CP, and we measured gene expression in inflammatory cytokine and signal transduction pathways. IL-1β and tumour necrosis factor (TNF)-α mRNA were induced from Y4 CP-treated THP-1 cells. IL-1β mRNA expression was increased according to the dose of Y4 CP, and in a time-dependent manner. IL-1β mRNA expression induced by Y4 CP (100 µg/ml) was approximately 7- to 10-fold greater than that in the control by real-time PCR analysis. Furthermore, neither PD98059, a specific inhibitor of extracellular signal-regulated kinase nor SB203580, a specific inhibitor of p38 kinase prevented the IL-1β expression induced by Y4 CP. However, JNK Inhibitor II, a specific inhibitor of c-Jun N-terminal kinase (JNK) prevented the IL-1β mRNA expression induced by Y4 CP in a concentration-dependent manner. These results indicate that Y4 CP-mediated JNK pathways play an important role in the regulation of IL-1β mRNA. Therefore, Y4 CP-transduced signals for IL-1β induction in the antibacterial action of macrophages may provide a therapeutic strategy for periodontitis. PMID:15996190

  5. PKCalpha-mediated ERK, JNK and p38 activation regulates the myogenic program in human rhabdomyosarcoma cells.

    PubMed

    Mauro, Annunziata; Ciccarelli, Carmela; De Cesaris, Paola; Scoglio, Arianna; Bouché, Marina; Molinaro, Mario; Aquino, Angelo; Zani, Bianca Maria

    2002-09-15

    We have previously suggested that PKCalpha has a role in 12-O-Tetradecanoylphorbol-13-acetate (TPA)-mediated growth arrest and myogenic differentiation in human embryonal rhabdomyosarcoma cells (RD). Here, by monitoring the signalling pathways triggered by TPA, we demonstrate that PKCalpha mediates these effects by inducing transient activation of c-Jun N-terminal protein kinases (JNKs) and sustained activation of both p38 kinase and extracellular signal-regulated kinases (ERKs) (all referred to as MAPKs). Activation of MAPKs following ectopic expression of constitutively active PKCalpha, but not its dominant-negative form, is also demonstrated. We investigated the selective contribution of MAPKs to growth arrest and myogenic differentiation by monitoring the activation of MAPK pathways, as well as by dissecting MAPK pathways using MEK1/2 inhibitor (UO126), p38 inhibitor (SB203580) and JNK and p38 agonist (anisomycin) treatments. Growth-arresting signals are triggered either by transient and sustained JNK activation (by TPA and anisomycin, respectively) or by preventing both ERK and JNK activation (UO126) and are maintained, rather than induced, by p38. We therefore suggest a key role for JNK in controlling ERK-mediated mitogenic activity. Notably, sarcomeric myosin expression is induced by both TPA and UO126 but is abrogated by the p38 inhibitor. This finding indicates a pivotal role for p38 in controlling the myogenic program. Anisomycin persistently activates p38 and JNKs but prevents myosin expression induced by TPA. In accordance with this negative role, reactivation of JNKs by anisomycin, in UO126-pre-treated cells, also prevents myosin expression. This indicates that, unlike the transient JNK activation that occurs in the TPA-mediated myogenic process, long-lasting JNK activation supports the growth-arrest state but antagonises p38-mediated myosin expression. Lastly, our results with the MEK inhibitor suggest a key role of the ERK pathway in regulating

  6. Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho

    Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promotermore » activity. The intracellular hydrogen peroxide (H{sub 2}O{sub 2}) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H{sub 2}O{sub 2} increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial

  7. c-Jun N-terminal kinase inhibitors: a patent review (2010 - 2014).

    PubMed

    Gehringer, Matthias; Muth, Felix; Koch, Pierre; Laufer, Stefan A

    2015-01-01

    c-Jun N-terminal kinases (JNKs) are involved in the emergence and progression of diverse pathologies such as neurodegenerative, cardiovascular and metabolic disorders as well as inflammation and cancer. In recent years, several highly selective pan-JNK inhibitors have been characterized and three chemical entities targeting JNKs have been investigated in clinical trials. This review summarizes patents claiming inhibitors of all JNK isoforms published between 2010 and 2014. Although primarily focusing on the patent literature, relevant peer-reviewed publications related to the covered patents have also been included. Moreover, key patents claiming novel applications of previously published chemical entities are reviewed. The article highlights a total of 28 patents from nine pharmaceutical companies and academic research groups. Although some selective pan-JNK inhibitors with reasonable in vivo profiles are now available, little is known about the isoform selectivity required for each particular indication and the development of isoform-selective JNK inhibitors still represents a challenge in JNK drug discovery. Moreover, isoform-selective tool compounds are a prerequisite to a comprehensive understanding of the biology of each JNK isoform. Potential approaches towards such compounds include the design of type-II and type-I(1)/2 binders, which are absent in the current JNK inhibitor portfolios, as well as the design of novel allosteric inhibitors. Furthermore, covalent inhibition, which already led to the first high-quality probe for JNKs, might be further exploited for gaining selectivity and in vivo efficacy. With regard to a potential therapeutic application, the recently proposed concept of covalent reversible inhibitors is expected to be attractive.

  8. Arachidonic acid induces macrophage cell cycle arrest through the JNK signaling pathway.

    PubMed

    Shen, Ziying; Ma, Yunqing; Ji, Zhonghao; Hao, Yang; Yan, Xuan; Zhong, Yuan; Tang, Xiaochun; Ren, Wenzhi

    2018-02-09

    Arachidonic acid (AA) has potent pro-apoptotic effects on cancer cells at a low concentration and on macrophages at a very high concentration. However, the effects of AA on the macrophage cell cycle and related signaling pathways have not been fully investigated. Herein we aim to observe the effect of AA on macrophages cell cycle. AA exposure reduced the viability and number of macrophages in a dose- and time-dependent manner. The reduction in RAW264.7 cell viability was not caused by apoptosis, as indicated by caspase-3 and activated caspase-3 detection. Further research illustrated that AA exposure induced RAW264.7 cell cycle arrested at S phase, and some cell cycle-regulated proteins were altered accordingly. Moreover, JNK signaling was stimulated by AA, and the stimulation was partially reversed by a JNK signaling inhibitor in accordance with cell cycle-related factors. In addition, nuclear and total Foxo1/3a and phosphorylated Foxo1/3a were elevated by AA in a dose- and time-dependent manner, and this elevation was suppressed by the JNK signaling inhibitor. Our study demonstrated that AA inhibits macrophage viability by inducing S phase cell cycle arrest. The JNK signaling pathway and the downstream FoxO transcription factors are involved in AA-induced RAW264.7 cell cycle arrest.

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chang, Y.-C.; Huang, H.-P.; Hsu, J.-D.

    Hibiscus sabdariffa Linne (Malvaceae), an attractive plant believed to be native to Africa, is cultivated in the Sudan and Eastern Taiwan. Anthocyanins exist widely in many vegetables and fruits. Some reports demonstrated that anthocyanins extracted from H. sabdariffa L., Hibiscus anthocyanins (HAs) (which are a group of natural pigments existing in the dried calyx of H. sabdariffa L.) exhibited antioxidant activity and liver protection. Therefore, in this study, we explored the effect of HAs on human cancer cells. The result showed that HAs could cause cancer cell apoptosis, especially in HL-60 cells. Using flow cytometry, we found that HAs treatmentmore » (0-4 mg/ml) markedly induced apoptosis in HL-60 cells in a dose- and time-dependent manner. The result also revealed increased phosphorylation in p38 and c-Jun, cytochrome c release, and expression of tBid, Fas, and FasL in the HAs-treated HL-60 cells. We further used SB203580 (p38 inhibitor), PD98059 (MEK inhibitor), SP600125 (JNK inhibitor), and wortmannin (phosphatidylinositol 3-kinase; PI-3K inhibitor) to evaluate their effect on the HAs-induced HL-60 death. The data showed that only SB203580 had strong potential in inhibiting HL-60 cell apoptosis and related protein expression and phosphorylation. Therefore, we suggested that HAs mediated HL-60 apoptosis via the p38-FasL and Bid pathway. According to these results, HAs could be developed as chemopreventive agents. However, further investigations into the specificity and mechanism(s) of HAs are needed.« less

  10. SPF-32629 A and B, novel human chymase inhibitors produced by Penicillium sp.

    PubMed

    Shimatani, Takuro; Hosotani, Nobuo; Ohnishi, Masako; Kumagai, Kazuo; Saji, Ikutaro

    2006-01-01

    Two new human chymase inhibitors, SPF-32629A and B, were isolated from the cultured broth of Penicillium sp. SPF-32629. These structures were determined by spectroscopic methods and identified as new pyridone compounds. SPF-32629B was the carboxylated derivative of SPF-32629A. SPF-32629A and B specifically inhibited human chymase among four serine proteases tested with the IC50 of 0.25 and 0.42 microg/ml, respectively.

  11. Toll-like receptor 4 mediates inflammatory signaling by bacterial lipopolysaccharide in human hepatic stellate cells.

    PubMed

    Paik, Yong-Han; Schwabe, Robert F; Bataller, Ramón; Russo, Maria P; Jobin, Christian; Brenner, David A

    2003-05-01

    Bacterial lipopolysaccharide (LPS) stimulates Kupffer cells and participates in the pathogenesis of alcohol-induced liver injury. However, it is unknown whether LPS directly affects hepatic stellate cells (HSCs), the main fibrogenic cell type in the injured liver. This study characterizes LPS-induced signal transduction and proinflammatory gene expression in activated human HSCs. Culture-activated HSCs and HSCs isolated from patients with hepatitis C virus-induced cirrhosis express LPS-associated signaling molecules, including CD14, toll-like receptor (TLR) 4, and MD2. Stimulation of culture-activated HSCs with LPS results in a rapid and marked activation of NF-kappaB, as assessed by in vitro kinase assays for IkappaB kinase (IKK), IkappaBalpha steady-state levels, p65 nuclear translocation, NF-kappaB-dependent luciferase reporter gene assays, and electrophoretic mobility shift assays. Lipid A induces NF-kappaB activation in a similar manner. Both LPS- and lipid A-induced NF-kappaB activation is blocked by preincubation with either anti-TLR4 blocking antibody (HTA125) or Polymyxin B. Lipid A induces NF-kappaB activation in HSCs from TLR4-sufficient (C3H/OuJ) mice but not from TLR4-deficient (C3H/HeJ) mice. LPS also activates c-Jun N-terminal kinase (JNK), as assessed by in vitro kinase assays. LPS up-regulates IL-8 and MCP-1 gene expression and secretion. LPS-induced IL-8 secretion is completely inhibited by the IkappaB super repressor (Ad5IkappaB) and partially inhibited by a specific JNK inhibitor, SP600125. LPS also up-regulates cell surface expression of ICAM-1 and VCAM-1. In conclusion, human activated HSCs utilize components of TLR4 signal transduction cascade to stimulate NF-kappaB and JNK and up-regulate chemokines and adhesion molecules. Thus, HSCs are a potential mediator of LPS-induced liver injury.

  12. Phenyl Saligenin Phosphate Induced Caspase-3 and c-Jun N-Terminal Kinase Activation in Cardiomyocyte-Like Cells.

    PubMed

    Felemban, Shatha G; Garner, A Christopher; Smida, Fathi A; Boocock, David J; Hargreaves, Alan J; Dickenson, John M

    2015-11-16

    At present, little is known about the effect(s) of organophosphorous compounds (OPs) on cardiomyocytes. In this study, we have investigated the effects of phenyl saligenin phosphate (PSP), two organophosphorothioate insecticides (diazinon and chlorpyrifos), and their acutely toxic metabolites (diazoxon and chlorpyrifos oxon) on mitotic and differentiated H9c2 cardiomyoblasts. OP-induced cytotoxicity was assessed by monitoring MTT reduction, LDH release, and caspase-3 activity. Cytotoxicity was not observed with diazinon, diazoxon, or chlorpyrifos oxon (48 h exposure; 200 μM). Chlorpyrifos-induced cytotoxicity was only evident at concentrations >100 μM. In marked contrast, PSP displayed pronounced cytotoxicity toward mitotic and differentiated H9c2 cells. PSP triggered the activation of JNK1/2 but not ERK1/2, p38 MAPK, or PKB, suggesting a role for this pro-apoptotic protein kinase in PSP-induced cell death. The JNK1/2 inhibitor SP 600125 attenuated PSP-induced caspase-3 and JNK1/2 activation, confirming the role of JNK1/2 in PSP-induced cytotoxicity. Fluorescently labeled PSP (dansylated PSP) was used to identify novel PSP binding proteins. Dansylated PSP displayed cytotoxicity toward differentiated H9c2 cells. 2D-gel electrophoresis profiles of cells treated with dansylated PSP (25 μM) were used to identify proteins fluorescently labeled with dansylated PSP. Proteomic analysis identified tropomyosin, heat shock protein β-1, and nucleolar protein 58 as novel protein targets for PSP. In summary, PSP triggers cytotoxicity in differentiated H9c2 cardiomyoblasts via JNK1/2-mediated activation of caspase-3. Further studies are required to investigate whether the identified novel protein targets of PSP play a role in the cytotoxicity of this OP, which is usually associated with the development of OP-induced delayed neuropathy.

  13. A liver full of JNK: signaling in regulation of cell function and disease pathogenesis, and clinical approaches.

    PubMed

    Seki, Ekihiro; Brenner, David A; Karin, Michael

    2012-08-01

    c-Jun-N-terminal kinase (JNK) is a mitogen-activated protein kinase family member that is activated by diverse stimuli, including cytokines (such as tumor necrosis factor and interleukin-1), reactive oxygen species (ROS), pathogens, toxins, drugs, endoplasmic reticulum stress, free fatty acids, and metabolic changes. Upon activation, JNK induces multiple biologic events through the transcription factor activator protein-1 and transcription-independent control of effector molecules. JNK isozymes regulate cell death and survival, differentiation, proliferation, ROS accumulation, metabolism, insulin signaling, and carcinogenesis in the liver. The biologic functions of JNK are isoform, cell type, and context dependent. Recent studies using genetically engineered mice showed that loss or hyperactivation of the JNK pathway contributes to the development of inflammation, fibrosis, cancer growth, and metabolic diseases that include obesity, hepatic steatosis, and insulin resistance. We review the functions and pathways of JNK in liver physiology and pathology and discuss findings from preclinical studies with JNK inhibitors. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

  14. Human amniotic epithelial stem cells promote wound healing by facilitating migration and proliferation of keratinocytes via ERK, JNK and AKT signaling pathways.

    PubMed

    Zhao, Bin; Liu, Jia-Qi; Zheng, Zhao; Zhang, Jun; Wang, Shu-Yue; Han, Shi-Chao; Zhou, Qin; Guan, Hao; Li, Chao; Su, Lin-Lin; Hu, Da-Hai

    2016-07-01

    Wound healing is a highly orchestrated physiological process consisting in a complex interaction of cellular and biochemical events. Human amniotic epithelial stem cells (HAESCs) have been shown to be an attractive resource for wound healing because they are primitive stem cells. However, the exact effects of amnion-derived stem cells on the migration or proliferation of keratinocytes and their potential mechanism are not fully understood. We have found that HAESCs accelerate the migration of keratinocytes and induce a remarkable increase in the activity of phospho-ERK, phospho-JNK, and phospho-AKT, the blockade of which by their specific inhibitors significantly inhibits migration induced by HAESC-conditioned medium (CM). Furthermore, the co-culture of keratinocytes with HAESCs up-regulates the expression levels of cell proliferation proteins Cyclin D1, Cyclin D3 and Mdm2. In vivo animal experiments have shown that HAESC-CM improves wound healing, whereas blockade with ERK, JNK and AKT inhibitors significantly impairs wound healing. Taken together, these results reveal, for the first time, that HAESCs promote wound healing by facilitating the migration and proliferation of keratinocytes via ERK, JNK and AKT signaling pathways and might be a potential therapy in skin wound healing.

  15. Lower Susceptibility of Female Mice to Acetaminophen Hepatotoxicity: Role of Mitochondrial Glutathione, Oxidant Stress and c-Jun N-Terminal Kinase

    PubMed Central

    Du, Kuo; Williams, C. David; McGill, Mitchell R.; Jaeschke, Hartmut

    2014-01-01

    Acetaminophen (APAP) overdose causes severe hepatotoxicity in animals and humans. However, the mechanisms underlying the gender differences in susceptibility to APAP overdose in mice have not been clarified. In our study, APAP (300 mg/kg) caused severe liver injury in male mice but 69-77% lower injury in females. No gender difference in metabolic activation of APAP was found. Hepatic glutathione (GSH) was rapidly depleted in both genders, while GSH recovery in female mice was 2.6 fold higher in mitochondria at 4h, and 2.5 and 3.3 fold higher in the total liver at 4h and 6h, respectively. This faster recovery of GSH, which correlated with greater induction of glutamate-cysteine ligase, attenuated mitochondrial oxidative stress in female mice, as suggested by a lower GSSG/GSH ratio at 6h (3.8% in males vs. 1.4% in females) and minimal centrilobular nitrotyrosine staining. While c-jun N-terminal kinase (JNK) activation was similar at 2 and 4h post-APAP, it was 3.1 fold lower at 6h in female mice. However, female mice were still protected by the JNK inhibitor SP600125. 17β-Estradiol pretreatment moderately decreased liver injury and oxidative stress in male mice without affecting GSH recovery. Conclusion: The lower susceptibility of female mice is achieved by the improved detoxification of reactive oxygen due to accelerated recovery of mitochondrial GSH levels, which attenuates late JNK activation and liver injury. However, even the reduced injury in female mice was still dependent on JNK. While 17β-estradiol partially protects male mice, it does not affect hepatic GSH recovery. PMID:25218290

  16. Ampelopsin-induced reactive oxygen species enhance the apoptosis of colon cancer cells by activating endoplasmic reticulum stress-mediated AMPK/MAPK/XAF1 signaling

    PubMed Central

    Park, Ga Bin; Jeong, Jee-Yeong; Kim, Daejin

    2017-01-01

    Ampelopsin (Amp) is bioactive natural product and exerts anti-cancer effects against several cancer types. The present study investigated the anti-colon cancer activity of Amp and explored its mechanism of action. The treatment of colon cancer cells with Amp resulted in the dose- and time-dependent induction of apoptosis via the activation of endoplasmic reticulum (ER) stress, 5′ adenosine monophosphate-activated protein kinase (AMPK), and c-Jun N-terminal protein kinase (JNK)/p38 mitogen-activated protein kinases (MAPKs). Salubrinal, an ER stress inhibitor, prevented the upregulation of ER stress-associated proteins, including phosphorylated protein kinase RNA-like ER kinase, phosphorylated eukaryotic translation initiation factor 2α, glucose-regulated protein 78, and CCAAT/enhancer-binding protein homologous protein, as well as suppressing AMPK activation and the MAPK signaling pathway. Knockdown of AMPK by RNA interference failed to block ER stress. Additionally, SP600125 (a JNK inhibitor) and SB203580 (a p38-MAPK inhibitor) effectively inhibited apoptosis and attenuated the expression of X-linked IAP-associated factor 1 (XAF1) and apoptotic Bcl-2 family proteins (BCL2 antagonist/killer 1 and BCL2-associated X protein) in Amp-treated colon cancer cells. Furthermore, reactive oxygen species (ROS)-mediated ER stress/AMPK apoptotic signaling pathway in Amp-treated colon cancer cells were markedly inhibited by treatment with N-acetyl-L-cysteine, a ROS scavenger. These results demonstrate that treatment with Amp induces the apoptotic death of colon cancer cells through ER stress-initiated AMPK/MAPK/XAF1 signaling. These results also provide experimental information for developing Amp as therapeutic drug against colon cancer. PMID:29250183

  17. The novel JNK inhibitor AS602801 inhibits cancer stem cells in vitro and in vivo.

    PubMed

    Okada, Masashi; Kuramoto, Kenta; Takeda, Hiroyuki; Watarai, Hikaru; Sakaki, Hirotsugu; Seino, Shizuka; Seino, Manabu; Suzuki, Shuhei; Kitanaka, Chifumi

    2016-05-10

    A phase 2 clinical trial investigating the efficacy and safety of AS602801, a newly developed JNK inhibitor, in the treatment of inflammatory endometriosis is complete. We are now examining whether AS602801 acts against human cancer cells in vitro and in vivo. In vitro, AS602801 exhibited cytotoxicity against both serum-cultured non-stem cancer cells and cancer stem cells derived from human pancreatic cancer, non-small cell lung cancer, ovarian cancer and glioblastoma at concentrations that did not decrease the viability of normal human fibroblasts. AS602801 also inhibited the self-renewal and tumor-initiating capacity of cancer stem cells surviving AS602801 treatment. Cancer stem cells in established xenograft tumors were reduced by systemic administration of AS602801 at a dose and schedule that did not adversely affect the health of the tumor-bearing mice. These findings suggest AS602801 is a promising anti-cancer stem cell agent, and further investigation of the utility of AS602801 in the treatment of cancer seems warranted.

  18. A1 adenosine receptor-induced phosphorylation and modulation of transglutaminase 2 activity in H9c2 cells: A role in cell survival.

    PubMed

    Vyas, Falguni S; Hargreaves, Alan J; Bonner, Philip L R; Boocock, David J; Coveney, Clare; Dickenson, John M

    2016-05-01

    The regulation of tissue transglutaminase (TG2) activity by the GPCR family is poorly understood. In this study, we investigated the modulation of TG2 activity by the A1 adenosine receptor in cardiomyocyte-like H9c2 cells. H9c2 cells were lysed following stimulation with the A1 adenosine receptor agonist N(6)-cyclopentyladenosine (CPA). Transglutaminase activity was determined using an amine incorporating and a protein cross linking assay. TG2 phosphorylation was assessed via immunoprecipitation and Western blotting. The role of TG2 in A1 adenosine receptor-induced cytoprotection was investigated by monitoring hypoxia-induced cell death. CPA induced time and concentration-dependent increases in amine incorporating and protein crosslinking activity of TG2. CPA-induced increases in TG2 activity were attenuated by the TG2 inhibitors Z-DON and R283. Responses to CPA were blocked by PKC (Ro 31-8220), MEK1/2 (PD 98059), p38 MAPK (SB 203580) and JNK1/2 (SP 600125) inhibitors and by removal of extracellular Ca(2+). CPA triggered robust increases in the levels of TG2-associated phosphoserine and phosphothreonine, which were attenuated by PKC, MEK1/2 and JNK1/2 inhibitors. Fluorescence microscopy revealed TG2-mediated biotin-X-cadaverine incorporation into proteins and proteomic analysis identified known (Histone H4) and novel (Hexokinase 1) protein substrates for TG2. CPA pre-treatment reversed hypoxia-induced LDH release and decreases in MTT reduction. TG2 inhibitors R283 and Z-DON attenuated A1 adenosine receptor-induced cytoprotection. TG2 activity was stimulated by the A1 adenosine receptor in H9c2 cells via a multi protein kinase dependent pathway. These results suggest a role for TG2 in A1 adenosine receptor-induced cytoprotection. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Tubeimoside-1 induces oxidative stress-mediated apoptosis and G0/G1 phase arrest in human prostate carcinoma cells in vitro

    PubMed Central

    Yang, Jing-bo; Khan, Muhammad; He, Yang-yang; Yao, Min; Li, Yong-ming; Gao, Hong-wen; Ma, Tong-hui

    2016-01-01

    Aim: Tubeimoside-1 (TBMS1), a triterpenoid saponin extracted from the Chinese herbal medicine Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae), has shown anticancer activities in various cancer cell lines. The aim of this study was to investigate the anticancer activity and molecular targets of TBMS1 in human prostate cancer cells in vitro. Methods: DU145 and P3 human prostate cancer cells were treated with TBMS1. Cell viability and apoptosis were detected. ROS generation, mitochondrial membrane potential and cell cycle profile were examined. Western blotting was used to measure the expression of relevant proteins in the cells. Results: TBMS1 (5–100 μmol/L) significantly suppressed the viability of DU145 and P3 cells with IC50 values of approximately 10 and 20 μmol/L, respectively. Furthermore, TBMS1 dose-dependently induced apoptosis and cell cycle arrest at G0/G1 phase in DU145 and P3 cells. In DU145 cells, TBMS1 induced mitochondrial apoptosis, evidenced by ROS generation, mitochondrial dysfunction, endoplasmic reticulum stress, modulated Bcl-2 family protein and cleaved caspase-3, and activated ASK-1 and its downstream targets p38 and JNK. The G0/G1 phase arrest was linked to increased expression of p53 and p21 and decreased expression of cyclin E and cdk2. Co-treatment with Z-VAD-FMK (pan-caspase inhibitor) could attenuate TBMS1-induced apoptosis but did not prevent G0/G1 arrest. Moreover, co-treatment with NAC (ROS scavenger), SB203580 (p38 inhibitor), SP600125 (JNK inhibitor) or salubrinal (ER stress inhibitor) significantly attenuated TBMS1-induced apoptosis. Conclusion: TBMS1 induces oxidative stress-mediated apoptosis in DU145 human prostate cancer cells in vitro via the mitochondrial pathway. PMID:27292614

  20. The Mechanism of Action of Zingerone in the Pacemaker Potentials of Interstitial Cells of Cajal Isolated from Murine Small Intestine.

    PubMed

    Kim, Jung Nam; Kim, Hyun Jung; Kim, Iksung; Kim, Yun Tai; Kim, Byung Joo

    2018-01-01

    Zingerone, a major component found in ginger root, is clinically effective for the treatment of various diseases. Interstitial cells of Cajal (ICCs) are the pacemaker cells responsible for slow waves in the gastrointestinal (GI) tract. We investigated the effects of zingerone on the pacemaker potentials of ICCs to assess its mechanisms of action and its potential as a treatment for GI tract motility disorder. We isolated ICCs from small intestines, and the whole-cell patch-clamp configuration was used to record the pacemaker potentials in cultured ICCs. Under the current clamping mode, zingerone inhibited pacemaker potentials of ICCs concentration-dependently. These effects were blocked not by capsazepine, a transient receptor potential vanilloid 1 (TRPV1) channel blocker, but by glibenclamide, a specific ATP-sensitive K+ channel blocker. Pretreatment with SQ-22536 (an adenylate cyclase inhibitor), LY294002 (a phosphoinositide 3-kinase inhibitor), and calphostin C (a protein kinase C (PKC) inhibitor) did not block the effects of zingerone on the pacemaker potentials relative to treatment with zingerone alone. However, zingerone-induced pacemaker potential inhibition was blocked by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ; a guanylate cyclase inhibitor), KT5823 (a protein kinase G (PKG) inhibitor), and L-NAME (a non-selective nitric oxide synthase (NOS) inhibitor). In addition, zingerone stimulated cyclic guanosine monophosphate (cGMP) production in ICCs. Finally, pretreatment with PD98059 (a p42/44 mitogen-activated protein kinase (MAPK) inhibitor), SB203580 (a p38 MAPK inhibitor), and SP600125 (c-Jun N-terminal kinases (JNK)-specific inhibitor) blocked the zingerone-induced pacemaker potential inhibition. These results suggest that zingerone concentration-dependently inhibits pacemaker potentials of ICCs via NO/cGMP-dependent ATP-sensitive K+ channels through MAPK-dependent pathways. Taken together, this study shows that zingerone may have the potential

  1. Lead optimization toward proof-of-concept tools for Huntington's disease within a 4-(1H-pyrazol-4-yl)pyrimidine class of pan-JNK inhibitors.

    PubMed

    Wityak, John; McGee, Kevin F; Conlon, Michael P; Song, Ren Hua; Duffy, Bryan C; Clayton, Brent; Lynch, Michael; Wang, Gwen; Freeman, Emily; Haber, James; Kitchen, Douglas B; Manning, David D; Ismail, Jiffry; Khmelnitsky, Yuri; Michels, Peter; Webster, Jeff; Irigoyen, Macarena; Luche, Michele; Hultman, Monica; Bai, Mei; Kuok, IokTeng D; Newell, Ryan; Lamers, Marieke; Leonard, Philip; Yates, Dawn; Matthews, Kim; Ongeri, Lynette; Clifton, Steve; Mead, Tania; Deupree, Susan; Wheelan, Pat; Lyons, Kathy; Wilson, Claire; Kiselyov, Alex; Toledo-Sherman, Leticia; Beconi, Maria; Muñoz-Sanjuan, Ignacio; Bard, Jonathan; Dominguez, Celia

    2015-04-09

    Through medicinal chemistry lead optimization studies focused on calculated properties and guided by X-ray crystallography and computational modeling, potent pan-JNK inhibitors were identified that showed submicromolar activity in a cellular assay. Using in vitro ADME profiling data, 9t was identified as possessing favorable permeability and a low potential for efflux, but it was rapidly cleared in liver microsomal incubations. In a mouse pharmacokinetics study, compound 9t was brain-penetrant after oral dosing, but exposure was limited by high plasma clearance. Brain exposure at a level expected to support modulation of a pharmacodynamic marker in mouse was achieved when the compound was coadministered with the pan-cytochrome P450 inhibitor 1-aminobenzotriazole.

  2. Psoralidin suppresses osteoclastogenesis in BMMs and attenuates LPS-mediated osteolysis by inhibiting inflammatory cytokines.

    PubMed

    Kong, Lingbo; Ma, Rui; Yang, Xiaobin; Zhu, Ziqi; Guo, Hua; He, Baorong; Wang, Biao; Hao, Dingjun

    2017-10-01

    Psoralidin is a metabolic product from the seed of psoraleacorylifolia, possessed anti-inflammatory and immunomodulatory effects. We speculated that psoralidin might impact osteoclastogenesis and bone loss. By using both in vitro and in vivo studies, we observed psoralidin strongly inhibited RANKL induced osteoclast formation during preosteoclast cultures, suggesting that it acts on osteoclast precursors to inhibit RANKL/RANK signaling. At the molecular level, by using MAPKs specific inhibitors (U-0126, SB-203580 and SP-600125) we demonstrated that psoralidin markedly abrogated the phosphorylation of p38, ERK, JNK. Moreover, the RANKL induced NF-κB/p65 phosphorylation and I-κB degradation were significantly inhibited by psoralidin. Further, psoralidin significantly suppressed osteoclastogenesis marker genes of TRAP, Cathepsin K and OSCAR. These were accompanied by the decreased expression of c-Fos and NFATc1 transcription factors. Consistent with in vitro results, our in vivo and serologic studies showed psoralidin inhibited lipopolysaccharide induced bone resorption by suppressing the inflammatory cytokines: TNF-α and IL-6 expression, as well as the ratio of RNAKL : OPG. These results collectively suggested that psoralidin could represent a novel therapeutic strategy for osteoclast-related disorders, such as rheumatoid arthritis and postmenopausal osteoporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Physalin B not only inhibits the ubiquitin-proteasome pathway but also induces incomplete autophagic response in human colon cancer cells in vitro

    PubMed Central

    Ma, Yi-ming; Han, Wei; Li, Jia; Hu, Li-hong; Zhou, Yu-bo

    2015-01-01

    Aim: To investigate the effects of physalin B insolated from Physalis divericata on human colon cancer cells in vitro and its anticancer mechanisms. Methods: Human HCT116 colon cancer cell line was tested. Cell viability and apoptosis were detected, and relevant proteins were measured using Western blot analyses. Autophagosomes were observed in stable GFP-LC3 HCT116 cells. Localization of autophagosomes and lysosomes was evaluated in GFP-LC3/RFP-LAMP1-co-transfected cells. Microtubules and F-actin microfilaments were observed with confocal microscope. Mitochondrial ROS (mito-ROS) was detected with flow cytometry in the cells stained with MitoSox dye. Results: Physalin B inhibited the viability of HCT116 cells with an IC50 value of 1.35 μmol/L. Treatment of the cells with physalin B (2.5–10 μmol/L) induced apoptosis and the cleavage of PARP and caspase-3. Meanwhile, physalin B treatment induced autophagosome formation, and accumulation of LC3-II and p62, but decreased Beclin 1 protein level. Marked changes of microtubules and F-actin microfilaments were observed in physalin B-treated cells, which led to the blockage of co-localization of autophagosomes and lysosomes. Physalin B treatment dose-dependently increased the phosphorylation of p38, ERK and JNK in the cells, whereas the p38 inhibitor SB202190, ERK inhibitor U0126 or JNK inhibitor SP600125 could partially reduce physalin B-induced PARP cleavage and p62 accumulation. Moreover, physalin B treatment dose-dependently increased mito-ROS production in the cells, whereas the ROS scavenger NAC could reverse physalin B-induced effects, including incomplete autophagic response, accumulation of ubiquitinated proteins, changes of microtubules and F-actin, activation of p38, ERK and JNK, as well as cell death and apoptosis. Conclusion: Physalin B induces mito-ROS, which not only inhibits the ubiquitin-proteasome pathway but also induces incomplete autophagic response in HCT116 cells in vitro. PMID:25832431

  4. Midazolam suppresses interleukin-1β-induced interleukin-6 release from rat glial cells

    PubMed Central

    2011-01-01

    Background Peripheral-type benzodiazepine receptor (PBR) expression levels are low in normal human brain, but their levels increase in inflammation, brain injury, neurodegenerative states and gliomas. It has been reported that PBR functions as an immunomodulator. The mechanisms of action of midazolam, a benzodiazepine, in the immune system in the CNS remain to be fully elucidated. We previously reported that interleukin (IL)-1β stimulates IL-6 synthesis from rat C6 glioma cells and that IL-1β induces phosphorylation of inhibitory kappa B (IκB), p38 mitogen-activated protein (MAP) kinase, stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2, and signal transducer and activator of transcription (STAT)3. It has been shown that p38 MAP kinase is involved in IL-1β-induced IL-6 release from these cells. In the present study, we investigated the effect of midazolam on IL-1β-induced IL-6 release from C6 cells, and the mechanisms of this effect. Methods Cultured C6 cells were stimulated by IL-1β. IL-6 release from C6 cells was measured using an enzyme-linked immunosorbent assay, and phosphorylation of IκB, the MAP kinase superfamily, and STAT3 was analyzed by Western blotting. Results Midazolam, but not propofol, inhibited IL-1β-stimulated IL-6 release from C6 cells. The IL-1β-stimulated levels of IL-6 were suppressed by wedelolactone (an inhibitor of IκB kinase), SP600125 (an inhibitor of SAPK/JNK), and JAK inhibitor I (an inhibitor of JAK 1, 2 and 3). However, IL-6 levels were not affected by PD98059 (an inhibitor of MEK1/2). Midazolam markedly suppressed IL-1β-stimulated STAT3 phosphorylation without affecting the phosphorylation of p38 MAP kinase, SAPK/JNK or IκB. Conclusion These results strongly suggest that midazolam inhibits IL-1β-induced IL-6 release in rat C6 glioma cells via suppression of STAT3 activation. Midazolam may affect immune system function in the CNS. PMID:21682888

  5. Nutlin-3 induces HO-1 expression by activating JNK in a transcription-independent manner of p53.

    PubMed

    Choe, Yun-Jeong; Lee, Sun-Young; Ko, Kyung Won; Shin, Seok Joon; Kim, Ho-Shik

    2014-03-01

    A recent study reported that p53 can induce HO-1 by directly binding to the putative p53 responsive element in the HO-1 promoter. In this study, we report that nutlin-3, a small molecule antagonist of HDM2, induces the transcription of HO-1 in a transcription-independent manner of p53. Nutlin-3 induced HO-1 expression at the level of transcription in human cancer cells such as U2OS and RKO cells. This induction of HO-1 did not occur in SAOS cells in which p53 was mutated and was prevented by knocking down the p53 protein using p53 siRNA transfection, but not by PFT-α, an inhibitor of the transcriptional activity of p53. Accompanying HO-1 expression, nutlin-3 stimulated the accumulation of ROS and the phosphorylation of MAPKs such as JNK, p38 MAPK and ERK1/2. Nutlin-3-induced HO-1 expression was suppressed by TEMPO, a ROS scavenger, and chemical inhibitors of JNK and p38 MAPK but not ERK1/2. In addition, nutlin‑3-induced phosphorylation of JNK but not p38 MAPK was inhibited by TEMPO. Notably, the levels of nutlin-3-induced ROS were correlated with the mitochondrial translocation of p53 and this induction was prevented by PFT-μ, an inhibitor of the mitochondrial translocation of p53. Consistent with the effect of the ROS scavenger and MAPK inhibitors, PFT-μ reduced HO-1 expression and the phosphorylation of JNK induced by nutlin-3. In the experiments of analyzing cell death, the knockdown of HO-1 augmented nutlin-3-induced apoptosis. Collectively, these results suggest that nutlin-3 induces HO-1 expression via the activation of both JNK which is dependent on ROS generated by p53 translocated to the mitochondria and p38 MAPK which appears to be stimulated by a ROS-independent mechanism, and this HO-1 induction may inhibit nutlin-3-induced apoptosis, constituting a negative feedback loop of p53-induced apoptosis.

  6. Phosphorylated Heat Shock Protein 20 (HSPB6) Regulates Transforming Growth Factor-α-Induced Migration and Invasion of Hepatocellular Carcinoma Cells.

    PubMed

    Matsushima-Nishiwaki, Rie; Toyoda, Hidenori; Nagasawa, Tomoaki; Yasuda, Eisuke; Chiba, Naokazu; Okuda, Seiji; Maeda, Atsuyuki; Kaneoka, Yuji; Kumada, Takashi; Kozawa, Osamu

    2016-01-01

    Human hepatocellular carcinoma (HCC) is one of the major malignancies in the world. Small heat shock proteins (HSPs) are reported to play an important role in the regulation of a variety of cancer cell functions, and the functions of small HSPs are regulated by post-translational modifications such as phosphorylation. We previously reported that protein levels of a small HSP, HSP20 (HSPB6), decrease in vascular invasion positive HCC compared with those in the negative vascular invasion. Therefore, in the present study, we investigated whether HSP20 is implicated in HCC cell migration and the invasion using human HCC-derived HuH7 cells. The transforming growth factor (TGF)-α-induced migration and invasion were suppressed in the wild-type-HSP20 overexpressed cells in which phosphorylated HSP20 was detected. Phospho-mimic-HSP20 overexpression reduced the migration and invasion compared with unphosphorylated HSP20 overexpression. Dibutyryl cAMP, which enhanced the phosphorylation of wild-type-HSP20, significantly reduced the TGF-α-induced cell migration of wild-type HSP20 overexpressed cells. The TGF-α-induced cell migration was inhibited by SP600125, a c-Jun N-terminal kinases (JNK) inhibitor. In phospho-mimic-HSP20 overexpressed HuH7 cells, TGF-α-stimulated JNK phosphorylation was suppressed compared with the unphosphorylated HSP20 overexpressed cells. Moreover, the level of phospho-HSP20 protein in human HCC tissues was significantly correlated with tumor invasion. Taken together, our findings strongly suggest that phosphorylated HSP20 inhibits TGF-α-induced HCC cell migration and invasion via suppression of the JNK signaling pathway.

  7. Vasoconstriction induced by G1, a G-protein-coupled oestrogen receptor1 (GPER-1) agonist, in the isolated perfused rat kidney.

    PubMed

    Kurt, Akif Hakan; Buyukafsar, Kansu

    2013-02-28

    Vascular effects of the G protein-coupled oestrogen receptor1 (GPER-1) agonist, G1 (10(-7)-5×10(-6) M), the main oestrogenic hormone, 17β-estradiol (10(-9)-10(-4) M), the NR3A1 agonist, PPT (10(-8)-10(-5) M), the NR3A2 agonist DPN (10(-8)-10(-5) M), and the classical oestrogen receptor blocker but also a GPER agonist, ICI-182780 (10(-8)-3×10(-6) M), were investigated on the perfusion pressure in the isolated rat kidney. To seek cellular mechanisms involved in GPER-1-induced signalling we tested several compounds including the inhibitors of Rho-kinase (ROCK) (Y-27632), tyrosine kinase (genistein), p38MAPK (SB203580), p44/42MAPK (PD98059), protein kinase C (PKC) (GF109203X), Jun-kinase (JNK) (SP600125), phosphatidylinositol-3-kinase (PI3K) (LY294002), Ca(2+) channels (nifedipine), GPER-1 (G15) and epidermal growth factor (EGF) receptor kinase (AG-1478). Moreover, the effect of saponin (50mg/ml) that was used for endothelium removal was explored on G1-elicited vascular action. G1, 17β-estradiol and ICI-182780 but not PPT and DPN induced vasoconstrictions in basal renal perfusion pressure. In contrast, G1 promoted vasodilatation when the perfusion pressure was elevated in advance by phenylephrine. G1-elicited vasoconstriction was not modified by endothelial removal; however, it was markedly inhibited by GPER-1 antagonist, G15. The vasoconstrictor response to G1 was also significantly attenuated by Y-27632, PD98059, SB203580, GF109203X, genistein, AG-1478, and nifedipine, but not LY294002 and SP600125. Western blotting indicated the expression of GPER-1 in renal artery, medulla and cortex of rat kidney. In conclusion, GPER-1 could substantially modulate vascular responses through a variety of signalling pathways including ROCK, PKC, p38 MAPK, p42/44 MAPK, tyrosine kinase, EGF receptor kinase and VOCC but not JNK or PI3K in isolated perfused rat kidney. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. The prototype HIV-1 maturation inhibitor, bevirimat, binds to the CA-SP1 cleavage site in immature Gag particles.

    PubMed

    Nguyen, Albert T; Feasley, Christa L; Jackson, Ken W; Nitz, Theodore J; Salzwedel, Karl; Air, Gillian M; Sakalian, Michael

    2011-12-07

    Bevirimat, the prototype Human Immunodeficiency Virus type 1 (HIV-1) maturation inhibitor, is highly potent in cell culture and efficacious in HIV-1 infected patients. In contrast to inhibitors that target the active site of the viral protease, bevirimat specifically inhibits a single cleavage event, the final processing step for the Gag precursor where p25 (CA-SP1) is cleaved to p24 (CA) and SP1. In this study, photoaffinity analogs of bevirimat and mass spectrometry were employed to map the binding site of bevirimat to Gag within immature virus-like particles. Bevirimat analogs were found to crosslink to sequences overlapping, or proximal to, the CA-SP1 cleavage site, consistent with previous biochemical data on the effect of bevirimat on Gag processing and with genetic data from resistance mutations, in a region predicted by NMR and mutational studies to have α-helical character. Unexpectedly, a second region of interaction was found within the Major Homology Region (MHR). Extensive prior genetic evidence suggests that the MHR is critical for virus assembly. This is the first demonstration of a direct interaction between the maturation inhibitor, bevirimat, and its target, Gag. Information gained from this study sheds light on the mechanisms by which the virus develops resistance to this class of drug and may aid in the design of next-generation maturation inhibitors.

  9. Caffeic Acid Phenethyl Ester Induces N-myc Downstream Regulated Gene 1 to Inhibit Cell Proliferation and Invasion of Human Nasopharyngeal Cancer Cells

    PubMed Central

    Chiang, Kun-Chun; Yang, Shih-Wei; Chang, Kai-Ping; Feng, Tsui-Hsia; Chang, Kang-Shuo; Tsui, Ke-Hung; Shin, Yi-Syuan; Chen, Chiu-Chun; Chao, Mei

    2018-01-01

    Caffeic acid phenethyl ester (CAPE), a bioactive component extracted from propolis, is widely studied due to its anti-cancer effect. Nasopharyngeal carcinoma (NPC) is distinct from other head and neck carcinomas and has a high risk of distant metastases. N-myc downstream regulated gene 1 (NDRG1) is demonstrated as a tumor suppressor gene in several cancers. Our result showed that CAPE treatment could repress NPC cell growth, through induction of S phase cell cycle arrest, and invasion. CAPE treatment stimulated NDRG1 expression in NPC cells. NDRG1 knockdown increased NPC cell proliferation and invasion and rendered NPC cells less responsive to CAPE growth-inhibiting effect, indicating CAPE repressed NPC cell growth partly through NDRG1indcution. CAPE treatment increased phosphorylation of ERK, JNK, and p38 in a dose- and time-dependent manner. Pre-treatments by inhibitors of ERK (PD0325901), JNK (SP600125), or p38 (SB201290), respectively, all could partly inhibit the CAPE effect on NDRG1 induction in NPC cells. Further, STAT3 activity was also repressed by CAPE in NPC cells. In summary, CAPE attenuates NPC cell proliferation and invasion by upregulating NDRG1 expression via MAPK pathway and by inhibiting phosphorylation of STAT3. Considering the poor prognosis of NPC patients with metastasis, CAPE could be a promising agent against NPC. PMID:29738439

  10. Genetic inhibition of JNK3 ameliorates spinal muscular atrophy.

    PubMed

    Genabai, Naresh K; Ahmad, Saif; Zhang, Zhanying; Jiang, Xiaoting; Gabaldon, Cynthia A; Gangwani, Laxman

    2015-12-15

    Mutation of the Survival Motor Neuron 1 (SMN1) gene causes spinal muscular atrophy (SMA), an autosomal recessive neurodegenerative disorder that occurs in early childhood. Degeneration of spinal motor neurons caused by SMN deficiency results in progressive muscle atrophy and death in SMA. The molecular mechanism underlying neurodegeneration in SMA is unknown. No treatment is available to prevent neurodegeneration and reduce the burden of illness in SMA. We report that the c-Jun NH2-terminal kinase (JNK) signaling pathway mediates neurodegeneration in SMA. The neuron-specific isoform JNK3 is required for neuron degeneration caused by SMN deficiency. JNK3 deficiency reduces degeneration of cultured neurons caused by low levels of SMN. Genetic inhibition of JNK pathway in vivo by Jnk3 knockout results in amelioration of SMA phenotype. JNK3 deficiency prevents the loss of spinal cord motor neurons, reduces muscle degeneration, improves muscle fiber thickness and muscle growth, improves motor function and overall growth and increases lifespan of mice with SMA that shows a systemic rescue of phenotype by a SMN-independent mechanism. JNK3 represents a potential (non-SMN) therapeutic target for the treatment of SMA. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Amyloid-β Reduces Exosome Release from Astrocytes by Enhancing JNK Phosphorylation.

    PubMed

    Abdullah, Mohammad; Takase, Hiroshi; Nunome, Mari; Enomoto, Hiroyuki; Ito, Jin-Ichi; Gong, Jian-Sheng; Michikawa, Makoto

    2016-07-02

    Exosomes are small extracellular vesicles secreted by variety of cell types such as neurons, astrocytes, and oligodendrocytes. It is suggested that exosomes play essential role in the maintenance of the neuronal functions and also in the clearance of amyloid-β (Aβ) from the brain. Aβ is well known to cause neuronal cell death, whereas little is known about its effect on astrocytes. In this study, we examined the effect of Aβ on release of exosomes from astrocytes in culture. We analyzed release of exosomes and apoE, both of which are known to remove/clear Aβ from the brain, in the culture medium of astrocytes. We found that exosome and apoE-HDL were successfully separated by density gradient ultracentrifugation demonstrated by distribution of their specific markers, flotillin and HSP90, and cholesterol, and morphological analysis using electron microscopy. Exosome release was significantly reduced by Aβ1-42 treatment in cultured astrocytes accompanied by an increased JNK phosphorylation. Whereas, apoE-HDL release remained unchanged. A JNK inhibitor restored the decreased levels of exosome release induced by Aβ treatment to levels similar to those of control, suggesting that Aβ1-42 inhibits exosome release via stimulation of JNK signal pathway. Because exosomes are shown to remove Aβ in the brain, our findings suggest that increased Aβ levels in the brain may impair the exosome-mediated Aβ clearance pathway.

  12. Lower susceptibility of female mice to acetaminophen hepatotoxicity: Role of mitochondrial glutathione, oxidant stress and c-jun N-terminal kinase

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Du, Kuo; Williams, C. David; McGill, Mitchell R.

    Acetaminophen (APAP) overdose causes severe hepatotoxicity in animals and humans. However, the mechanisms underlying the gender differences in susceptibility to APAP overdose in mice have not been clarified. In our study, APAP (300 mg/kg) caused severe liver injury in male mice but 69–77% lower injury in females. No gender difference in metabolic activation of APAP was found. Hepatic glutathione (GSH) was rapidly depleted in both genders, while GSH recovery in female mice was 2.6 fold higher in the mitochondria at 4 h, and 2.5 and 3.3 fold higher in the total liver at 4 h and 6 h, respectively. Thismore » faster recovery of GSH, which correlated with greater induction of glutamate-cysteine ligase, attenuated mitochondrial oxidative stress in female mice, as suggested by a lower GSSG/GSH ratio at 6 h (3.8% in males vs. 1.4% in females) and minimal centrilobular nitrotyrosine staining. While c-jun N-terminal kinase (JNK) activation was similar at 2 and 4 h post-APAP, it was 3.1 fold lower at 6 h in female mice. However, female mice were still protected by the JNK inhibitor SP600125. 17β-Estradiol pretreatment moderately decreased liver injury and oxidative stress in male mice without affecting GSH recovery. Conclusion: The lower susceptibility of female mice is achieved by the improved detoxification of reactive oxygen due to accelerated recovery of mitochondrial GSH levels, which attenuates late JNK activation and liver injury. However, even the reduced injury in female mice was still dependent on JNK. While 17β-estradiol partially protects male mice, it does not affect hepatic GSH recovery. - Highlights: • Female mice are less susceptible to acetaminophen overdose than males. • GSH depletion and protein adduct formation are similar in both genders. • Recovery of hepatic GSH levels is faster in females and correlates with Gclc. • Reduced oxidant stress in females leads to reduced JNK activation. • JNK activation and mitochondrial translocation are

  13. β3-adrenergic receptor activation induces TGFβ1 expression in cardiomyocytes via the PKG/JNK/c-Jun pathway.

    PubMed

    Xu, Zhongcheng; Wu, Jimin; Xin, Junzhou; Feng, Yenan; Hu, Guomin; Shen, Jing; Li, Mingzhe; Zhang, Youyi; Xiao, Han; Wang, Li

    2018-06-05

    In heart failure, the expression of cardiac β 3 -adrenergic receptors (β 3 -ARs) increases. However, the precise role of β 3 -AR signaling within cardiomyocytes remains unclear. Transforming growth factor β1 (TGFβ1) is a crucial cytokine mediating the cardiac remodeling that plays a causal role in the progression of heart failure. Here, we set out to determine the effect of β 3 -AR activation on TGFβ1 expression in rat cardiomyocytes and examine the underlying mechanism. The selective β 3 -AR agonist BRL37344 induced an increase in TGFβ1 expression and the phosphorylation of c-Jun N-terminal kinase (JNK) and c-Jun in β 3 -AR-overexpressing cardiomyocytes. Those effects of BRL37344 were suppressed by a β 3 -AR antagonist. Moreover, the inhibition of JNK and c-Jun activity by a JNK inhibitor and c-Jun siRNA blocked the increase in TGFβ1 expression upon β 3 -AR activation. A protein kinase G (PKG) inhibitor also attenuated β 3 -AR-agonist-induced TGFβ1 expression and the phosphorylation of JNK and c-Jun. In conclusion, the β 3 -AR activation in cardiomyocytes increases the expression of TGFβ1 via the PKG/JNK/c-Jun pathway. These results help us further understand the role of β 3 -AR signaling in heart failure. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Inhibitor of apoptosis signal-regulating kinase 1 protects against acetaminophen-induced liver injury

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xie, Yuchao; Ramachandran, Anup; Breckenridge, David G.

    Metabolic activation and oxidant stress are key events in the pathophysiology of acetaminophen (APAP) hepatotoxicity. The initial mitochondrial oxidative stress triggered by protein adduct formation is amplified by c-jun-N-terminal kinase (JNK), resulting in mitochondrial dysfunction and ultimately cell necrosis. Apoptosis signal-regulating kinase 1 (ASK1) is considered the link between oxidant stress and JNK activation. The objective of the current study was to assess the efficacy and mechanism of action of the small-molecule ASK1 inhibitor GS-459679 in a murine model of APAP hepatotoxicity. APAP (300 mg/kg) caused extensive glutathione depletion, JNK activation and translocation to the mitochondria, oxidant stress and livermore » injury as indicated by plasma ALT activities and area of necrosis over a 24 h observation period. Pretreatment with 30 mg/kg of GS-459679 almost completely prevented JNK activation, oxidant stress and injury without affecting the metabolic activation of APAP. To evaluate the therapeutic potential of GS-459679, mice were treated with APAP and then with the inhibitor. Given 1.5 h after APAP, GS-459679 was still protective, which was paralleled by reduced JNK activation and p-JNK translocation to mitochondria. However, GS-459679 treatment was not more effective than N-acetylcysteine, and the combination of GS-459679 and N-acetylcysteine exhibited similar efficacy as N-acetylcysteine monotherapy, suggesting that GS-459769 and N-acetylcysteine affect the same pathway. Importantly, inhibition of ASK1 did not impair liver regeneration as indicated by PCNA staining. In conclusion, the ASK1 inhibitor GS-459679 protected against APAP toxicity by attenuating JNK activation and oxidant stress in mice and may have therapeutic potential for APAP overdose patients. - Highlights: • Two ASK1 inhibitors protected against acetaminophen-induced liver injury. • The ASK1 inhibitors protect when used as pre- or post-treatment. • Protection by ASK1

  15. Mycoplasma fermentans and TNF-β interact to amplify immune-modulating cytokines in human lung fibroblasts

    PubMed Central

    Fabisiak, James P.; Gao, Fei; Thomson, Robyn G.; Strieter, Robert M.; Watkins, Simon C.; Dauber, James H.

    2010-01-01

    Mycoplasma can establish latent infections and are associated with arthritis, leukemia, and chronic lung disease. We developed an experimental model in which lung cells are deliberately infected with Mycoplasma fermentans. Human lung fibroblasts (HLF) were exposed to live M. fermentans and immune-modulating cytokine release was assessed with and without known inducers of cytokine production. M. fermentans increased IL-6, IL-8/CXCL8, MCP-1/CCL2, and Gro-α/CXCL1 production. M. fermentans interacted with TNF-β to release more IL-6, CXCL8, and CXCL1 than predicted by the responses to either stimulus alone. The effects of live infection were recapitulated by exposure to M. fermentans-derived macrophage-activating lipopeptide-2 (MALP-2), a Toll-like receptor-2- and receptor-6-specific ligand. The synergistic effect of combined stimuli was more pronounced with prolonged incubations. Preexposure to TNF-β sensitized the cells to subsequent MALP-2 challenge, but preexposure to MALP-2 did not alter the IL-6 response to TNF-β. Exposure to M. fermentans or MALP-2 did not enhance nuclear localization, DNA binding, or transcriptional activity of NF-κB and did not modulate early NF-κB activation in response to TNF-β. Application of specific inhibitors of various MAPKs suggested that p38 and JNK/stress-activated protein kinase were involved in early IL-6 release after exposure to TNF-β and M. fermentans, respectively. The combined response to M. fermentans and TNF-β, however, was uniquely sensitive to delayed application of SP-600125, suggesting that JNK/stress-activated protein kinase contributes to the amplification of IL-6 release. Thus M. fermentans interacts with stimuli such as TNF-β to amplify lung cell production of immune-modulating cytokines. The mechanisms accounting for this interaction can now be dissected with the use of this in vitro model. PMID:16751226

  16. c-Jun N-terminal kinase 3 (JNK3) Mediates Paraquat- and Rotenone-Induced Dopaminergic Neuron Death

    PubMed Central

    Choi, Won Seok; Abel, Glen; Klintworth, Heather; Flavell, Richard A.; Xia, Zhengui

    2011-01-01

    Mechanistic studies underlying dopaminergic neuron death may identify new drug targets for the treatment of Parkinson disease (PD). Epidemiological studies have linked pesticide exposure to increased risk for sporadic PD. Here, we investigated the role of c-Jun N-terminal kinase 3 (JNK3), a neural-specific JNK isoform, in dopaminergic neuron death induced by the pesticides rotenone and paraquat. The role of JNK3 was evaluated using RNA silencing and gene deletion to block JNK3 signaling. Using an antibody that recognizes all isoforms of activated JNKs, we found that paraquat and rotenone stimulate JNK phosphorylation in primary cultured dopaminergic neurons. In cultured neurons transfected with Jnk3-specific siRNA and in neurons from Jnk3−/− mice, JNK phosphorylation was nearly abolished, suggesting that JNK3 is the main JNK isoform activated in dopaminergic neurons by these pesticides. Paraquat- and rotenone-induced death of dopaminergic neurons was also significantly reduced by Jnk3 siRNA or Jnk3 gene deletion and deletion of the Jnk3 gene completely attenuated paraquat-induced dopaminergic neuron death and motor-deficits in vivo. Our data identify JNK3 as a common and critical mediator of dopaminergic neuron death induced by paraquat and rotenone, suggesting that it is a potential drug target for PD treatment. PMID:20418776

  17. The Green Tea Component (-)-Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity

    PubMed Central

    Lee, Hyeon-Ju; Byun, Catherine Jeonghae; Park, Jung-Hyun; Park, Jae Hoon; Cho, Ho-Seong; Cho, Sung-Jin; Jo, Sangmee Ahn; Jo, Inho

    2015-01-01

    The green tea component (-)-epigallocatechin-3-gallate (EGCG) has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As) or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC) at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose) polymerase (PARP), activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As) treatment significantly induced production of reactive oxygen species (ROS), which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK), which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity. PMID:26375285

  18. The Green Tea Component (-)-Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity.

    PubMed

    Kim, Jee-Youn; Choi, Ji-Young; Lee, Hyeon-Ju; Byun, Catherine Jeonghae; Park, Jung-Hyun; Park, Jae Hoon; Cho, Ho-Seong; Cho, Sung-Jin; Jo, Sangmee Ahn; Jo, Inho

    2015-01-01

    The green tea component (-)-epigallocatechin-3-gallate (EGCG) has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As) or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC) at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose) polymerase (PARP), activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As) treatment significantly induced production of reactive oxygen species (ROS), which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK), which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity.

  19. JNK1 controls adult hippocampal neurogenesis and imposes cell-autonomous control of anxiety behaviour from the neurogenic niche

    PubMed Central

    Mohammad, H; Marchisella, F; Ortega-Martinez, S; Hollos, P; Eerola, K; Komulainen, E; Kulesskaya, N; Freemantle, E; Fagerholm, V; Savontous, E; Rauvala, H; Peterson, B D; van Praag, H; Coffey, E T

    2018-01-01

    Promoting adult hippocampal neurogenesis is expected to induce neuroplastic changes that improve mood and alleviate anxiety. However, the underlying mechanisms remain largely unknown and the hypothesis itself is controversial. Here we show that mice lacking Jnk1, or c-Jun N-terminal kinase (JNK) inhibitor-treated mice, display increased neurogenesis in adult hippocampus characterized by enhanced cell proliferation and survival, and increased maturation in the ventral region. Correspondingly, anxiety behaviour is reduced in a battery of tests, except when neurogenesis is prevented by AraC treatment. Using engineered retroviruses, we show that exclusive inhibition of JNK in adult-born granule cells alleviates anxiety and reduces depressive-like behaviour. These data validate the neurogenesis hypothesis of anxiety. Moreover, they establish a causal role for JNK in the hippocampal neurogenic niche and anxiety behaviour, and advocate targeting of JNK as an avenue for novel therapies against affective disorders. PMID:27843149

  20. Sulforaphane attenuates microglia-mediated neuronal necroptosis through down-regulation of MAPK/NF-κB signaling pathways in LPS-activated BV-2 microglia.

    PubMed

    Qin, Sisi; Yang, Canhong; Huang, Weihua; Du, Shuhua; Mai, Hantao; Xiao, Jijie; Lü, Tianming

    2018-01-31

    Sulforaphane (SFN), a natural dietary isothiocyanate in cruciferous vegetables such as broccoli and cabbage, has very strong anti-inflammatory activity. Activation of microglia leads to overexpression of a series of pro-inflammatory mediators, which play a vital role in neuronal damage. SFN may have neuroprotective effects in different neurodegenerative diseases related to inflammation. However, the mechanisms underlying SFN's protection of neurons against microglia-mediated neuronal damage are not fully understood. Here, we investigated how SFN attenuated microglia-mediated neuronal damage. Our results showed that SFN could not directly protect the viability of neurons following pro-inflammatory mediators, but increased the viability of BV-2 microglia and down-regulated the mRNA and protein levels of pro-inflammatory mediators including TNF-α, IL-1β, IL-6 and iNOS in a concentration-dependent manner in BV-2 cells. SFN also significantly blocked the phosphorylation of MAPKs (p38, JNK, and ERK1/2) and NF-κB p65, both by itself and with MAPK inhibitors (SB203580, SP 600125, and U0126) or an NF-κB inhibitor (PDTC). The expression of pro-inflammatory proteins was also blocked by SFN with or without inhibitors. Further, SFN indirectly increased the viability and maintained the morphology of neurons, and the protein expression of RIPK3 and MLKL was significantly suppressed by SFN in neuronal necroptosis through p38, JNK, and NF-κB p65 but not ERK1/2 signaling pathways. Together, our results demonstrate that SFN attenuates LPS-induced pro-inflammatory responses through down-regulation of MAPK/NF-κB signaling pathway in BV-2 microglia and thus indirectly suppresses microglia-mediated neuronal damage. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Indoxyl sulfate enhances IL-1β-induced E-selectin expression in endothelial cells in acute kidney injury by the ROS/MAPKs/NFκB/AP-1 pathway.

    PubMed

    Shen, Wen-Ching; Liang, Chan-Jung; Huang, Tao-Ming; Liu, Chen-Wei; Wang, Shu-Huei; Young, Guang-Huar; Tsai, Jaw-Shiun; Tseng, Ying-Chin; Peng, Yu-Sen; Wu, Vin-Cent; Chen, Yuh-Lien

    2016-11-01

    Uremic toxins are considered a risk factor for cardiovascular disorders in kidney diseases, but it is not known whether, under inflammatory conditions, they affect adhesion molecule expression on endothelial cells, which may play a critical role in acute kidney injury (AKI). In the present study, in cardiovascular surgery-related AKI patients, who are known to have high plasma levels of the uremic toxin indoxyl sulfate (IS), plasma levels of IL-1β were found to be positively correlated with plasma levels of the adhesion molecule E-selectin. In addition, high E-selectin and IL-1β expression were seen in the kidney of ischemia/reperfusion mice in vivo. We also examined the effects of IS on E-selectin expression by IL-1β-treated human umbilical vein endothelial cells (HUVECs) and the underlying mechanism. IS pretreatment of HUVECs significantly increased IL-1β-induced E-selectin expression, monocyte adhesion, and the phosphorylation of mitogen-activated protein kinases (ERK, p38, and JNK) and transcription factors (NF-κB and AP-1), and phosphorylation was decreased by pretreatment with inhibitors of ERK1/2 (PD98059), p38 MAPK (SB202190), and JNK (SP600125). Furthermore, IS increased IL-1β-induced reactive oxygen species (ROS) production and this effect was inhibited by pretreatment with N-acetylcysteine (a ROS scavenger) or apocynin (a NADPH oxidase inhibitor). Gel shift assays and ChIP-PCR demonstrated that IS enhanced E-selectin expression in IL-1-treated HUVECs by increasing NF-κB and AP-1 DNA-binding activities. Moreover, IS-enhanced E-selectin expression in IL-1β-treated HUVECs was inhibited by Bay11-7082, a NF-κB inhibitor. Thus, IS may play an important role in the development of cardiovascular disorders in kidney diseases during inflammation by increasing endothelial expression of E-selectin.

  2. Depigmenting Effect of Resveratrol Is Dependent on FOXO3a Activation without SIRT1 Activation.

    PubMed

    Kwon, Soon-Hyo; Choi, Hye-Ryung; Kang, Youn-A; Park, Kyoung-Chan

    2017-06-07

    Resveratrol exhibits not only anti-melanogenic property by inhibiting microphthalmia-associated transcription factor (MITF), but also anti-aging property by activating sirtuin-1 (SIRT1). In this study, the relationship between depigmenting effect of resveratrol and SIRT1/forkhead box O (FOXO) 3a activation and was investigated. Resveratrol suppressed melanogenesis by the downregulation of MITF and tyrosinase via ERK pathway. Results showed that the expression of both SIRT1 and FOXO3a were increased. It is reported that SIRT1 is critical regulator of FOXO-mediated transcription in response to oxidative stress. However in our study, FOXO3a activation appeared earlier than that of SIRT1. Furthermore, the effect of resveratrol on the levels of MITF and tyrosinase was suppressed when melanocytes were pre-treated with SP600125 (JNK inhibitor). However, pre-treatment with SIRT1 inhibitor (EX527, or sirtinol) did not affect the levels of MITF and tyrosinase. Therefore, resveratrol inhibits melanogenesis through the activation of FOXO3a but not by the activation of SIRT1. Although SIRT1 activation by resveratrol is a well-known mechanism of resveratrol-induced antiaging effects, our study showed that not SIRT1 but FOXO3a activation is involved in depigmenting effects of resveratrol.

  3. NADPH oxidase/ROS-dependent PYK2 activation is involved in TNF-α-induced matrix metalloproteinase-9 expression in rat heart-derived H9c2 cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Chuen-Mao, E-mail: chuenmao@mail.cgu.edu.tw; Heart Failure Center, Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Lee, I-Ta

    TNF-α plays a mediator role in the pathogenesis of chronic heart failure contributing to cardiac remodeling and peripheral vascular disturbances. The implication of TNF-α in inflammatory responses has been shown to be mediated through up-regulation of matrix metalloproteinase-9 (MMP-9). However, the detailed mechanisms of TNF-α-induced MMP-9 expression in rat embryonic-heart derived H9c2 cells are largely not defined. We demonstrated that in H9c2 cells, TNF-α induced MMP-9 mRNA and protein expression associated with an increase in the secretion of pro-MMP-9. TNF-α-mediated responses were attenuated by pretreatment with the inhibitor of ROS (N-acetyl-L-cysteine, NAC), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)],more » MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), NF-κB (Bay11-7082), or PYK2 (PF-431396) and transfection with siRNA of TNFR1, p47{sup phox}, p42, p38, JNK1, p65, or PYK2. Moreover, TNF-α markedly induced NADPH oxidase-derived ROS generation in these cells. TNF-α-enhanced p42/p44 MAPK, p38 MAPK, JNK1/2, and NF-κB (p65) phosphorylation and in vivo binding of p65 to the MMP-9 promoter were inhibited by U0126, SB202190, SP600125, NAC, DPI, or APO. In addition, TNF-α-mediated PYK2 phosphorylation was inhibited by NAC, DPI, or APO. PYK2 inhibition could reduce TNF-α-stimulated MAPKs and NF-κB activation. Thus, in H9c2 cells, we are the first to show that TNF-α-induced MMP-9 expression is mediated through a TNFR1/NADPH oxidase/ROS/PYK2/MAPKs/NF-κB cascade. We demonstrated that NADPH oxidase-derived ROS generation is involved in TNF-α-induced PYK2 activation in these cells. Understanding the regulation of MMP-9 expression and NADPH oxidase activation by TNF-α on H9c2 cells may provide potential therapeutic targets of chronic heart failure. - Highlights: • TNF-α induces MMP-9 secretion and expression via a TNFR1-dependent pathway. • TNF-α induces ROS/PYK2-dependent MMP-9 expression in H9c2 cells. • TNF

  4. A Quantitative RNAi Screen for JNK Modifiers Identifies Pvr as a Novel Regulator of Drosophila Immune Signaling

    PubMed Central

    Bond, David; Foley, Edan

    2009-01-01

    Drosophila melanogaster responds to gram-negative bacterial challenges through the IMD pathway, a signal transduction cassette that is driven by the coordinated activities of JNK, NF-κB and caspase modules. While many modifiers of NF-κB activity were identified in cell culture and in vivo assays, the regulatory apparatus that determines JNK inputs into the IMD pathway is relatively unexplored. In this manuscript, we present the first quantitative screen of the entire genome of Drosophila for novel regulators of JNK activity in the IMD pathway. We identified a large number of gene products that negatively or positively impact on JNK activation in the IMD pathway. In particular, we identified the Pvr receptor tyrosine kinase as a potent inhibitor of JNK activation. In a series of in vivo and cell culture assays, we demonstrated that activation of the IMD pathway drives JNK-dependent expression of the Pvr ligands, Pvf2 and Pvf3, which in turn act through the Pvr/ERK MAP kinase pathway to attenuate the JNK and NF-κB arms of the IMD pathway. Our data illuminate a poorly understood arm of a critical and evolutionarily conserved innate immune response. Furthermore, given the pleiotropic involvement of JNK in eukaryotic cell biology, we believe that many of the novel regulators identified in this screen are of interest beyond immune signaling. PMID:19893628

  5. TRX-ASK1-JNK signaling regulation of cell density-dependent cytotoxicity in cigarette smoke-exposed human bronchial epithelial cells.

    PubMed

    Lee, Yong Chan; Chuang, Chun-Yu; Lee, Pak-Kei; Lee, Jin-Soo; Harper, Richart W; Buckpitt, Alan B; Wu, Reen; Oslund, Karen

    2008-05-01

    Cigarette smoke is a major environmental air pollutant that injures airway epithelium and incites subsequent diseases including chronic obstructive pulmonary disease. The lesion that smoke induces in airway epithelium is still incompletely understood. Using a LIVE/DEAD cytotoxicity assay, we observed that subconfluent cultures of bronchial epithelial cells derived from both human and monkey airway tissues and an immortalized normal human bronchial epithelial cell line (HBE1) were more susceptible to injury by cigarette smoke extract (CSE) and by direct cigarette smoke exposure than cells in confluent cultures. Scraping confluent cultures also caused an enhanced cell injury predominately in the leading edge of the scraped confluent cultures by CSE. Cellular ATP levels in both subconfluent and confluent cultures were drastically reduced after CSE exposure. In contrast, GSH levels were significantly reduced only in subconfluent cultures exposed to smoke and not in confluent cultures. Western blot analysis demonstrated ERK activation in both confluent and subconfluent cultures after CSE. However, activation of apoptosis signal-regulating kinase 1 (ASK1), JNK, and p38 were demonstrated only in subconfluent cultures and not in confluent cultures after CSE. Using short interfering RNA (siRNA) to JNK1 and JNK2 and a JNK inhibitor, we attenuated CSE-mediated cell death in subconfluent cultures but not with an inhibitor of the p38 pathway. Using the tetracycline (Tet)-on inducible approach, overexpression of thioredoxin (TRX) attenuated CSE-mediated cell death and JNK activation in subconfluent cultures. These results suggest that the TRX-ASK1-JNK pathway may play a critical role in mediating cell density-dependent CSE cytotoxicity.

  6. Effects of Korean Red Ginseng extract on tissue plasminogen activator and plasminogen activator inhibitor-1 expression in cultured rat primary astrocytes

    PubMed Central

    Ko, Hyun Myung; Joo, So Hyun; Kim, Pitna; Park, Jin Hee; Kim, Hee Jin; Bahn, Geon Ho; Kim, Hahn Young; Lee, Jongmin; Han, Seol-Heui; Shin, Chan Young; Park, Seung Hwa

    2013-01-01

    Korean Red Ginseng (KRG) is an oriental herbal preparation obtained from Panax ginseng Meyer (Araliaceae). To expand our understanding of the action of KRG on central nervous system (CNS) function, we examined the effects of KRG on tissue plasminogen activator (tPA)/plasminogen activator inhibitor-1 (PAI-1) expression in rat primary astrocytes. KRG extract was treated in cultured rat primary astrocytes and neuron in a concentration range of 0.1 to 1.0 mg/mL and the expression of functional tPA/PAI-1 was examined by casein zymography, Western blot and reverse transcription-polymerase chain reaction. KRG extracts increased PAI-1 expression in rat primary astrocytes in a concentration dependent manner (0.1 to 1.0 mg/mL) without affecting the expression of tPA itself. Treatment of 1.0 mg/mL KRG increased PAI-1 protein expression in rat primary astrocytes to 319.3±65.9% as compared with control. The increased PAI-1 expression mediated the overall decrease in tPA activity in rat primary astrocytes. Due to the lack of PAI-1 expression in neuron, KRG did not affect tPA activity in neuron. KRG treatment induced a concentration dependent activation of PI3K, p38, ERK1/2, and JNK in rat primary astrocytes and treatment of PI3K or MAPK inhibitors such as LY294002, U0126, SB203580, and SP600125 (10 μM each), significantly inhibited 1.0 mg/mL KRG-induced expression of PAI- 1 and down-regulation of tPA activity in rat primary astrocytes. Furthermore, compound K but not other ginsenosides such as Rb1 and Rg1 induced PAI-1 expression. KRG-induced up-regulation of PAI-1 in astrocytes may play important role in the regulation of overall tPA activity in brain, which might underlie some of the beneficial effects of KRG on CNS such as neuroprotection in ischemia and brain damaging condition as well as prevention or recovery from addiction. PMID:24235858

  7. Domain Specificity of MAP3K Family Members, MLK and Tak1, for JNK Signaling in Drosophila

    PubMed Central

    Stronach, Beth; Lennox, Ashley L.; Garlena, Rebecca A.

    2014-01-01

    A highly diverse set of protein kinases functions as early responders in the mitogen- and stress-activated protein kinase (MAPK/SAPK) signaling pathways. For instance, humans possess 14 MAPK kinase kinases (MAP3Ks) that activate Jun kinase (JNK) signaling downstream. A major challenge is to decipher the selective and redundant functions of these upstream MAP3Ks. Taking advantage of the relative simplicity of Drosophila melanogaster as a model system, we assessed MAP3K signaling specificity in several JNK-dependent processes during development and stress response. Our approach was to generate molecular chimeras between two MAP3K family members, the mixed lineage kinase, Slpr, and the TGF-β activated kinase, Tak1, which share 32% amino acid identity across the kinase domain but otherwise differ in sequence and domain structure, and then test the contributions of various domains for protein localization, complementation of mutants, and activation of signaling. We found that overexpression of the wild-type kinases stimulated JNK signaling in alternate contexts, so cells were capable of responding to both MAP3Ks, but with distinct outcomes. Relative to wild-type, the catalytic domain swaps compensated weakly or not at all, despite having a shared substrate, the JNK kinase Hep. Tak1 C-terminal domain-containing constructs were inhibitory in Tak1 signaling contexts, including tumor necrosis factor-dependent cell death and innate immune signaling; however, depressing antimicrobial gene expression did not necessarily cause phenotypic susceptibility to infection. These same constructs were neutral in the context of Slpr-dependent developmental signaling, reflecting differential subcellular protein localization and by inference, point of activation. Altogether, our findings suggest that the selective deployment of a particular MAP3K can be attributed in part to its inherent sequence differences, cellular localization, and binding partner availability. PMID:24429281

  8. P27/Kip1 is responsible for magnolol-induced U373 apoptosis in vitro and in vivo.

    PubMed

    Chen, Li-Ching; Lee, Wen-Sen

    2013-03-20

    Previously, we demonstrated that magnolol, a hydroxylated biphenyl compound isolated from the bark of Magnolia officinalis, at low concentrations (3-10 μM) exerted an antiproliferation effect in colon cancer, hepatoma, and glioblastoma (U373) cell lines through upregulation of the p21/Cip1 protein. Magnolol at a higher concentration of 100 μM, however, induced apoptosis and upregulated p27/Kip1 expression in U373. In the present study, we further studied whether the increased p27/Kip1 expression contributes to the magnolol-induced apoptosis in U373. Our data show that knock-down of p27/Kip1 expression significantly suppressed the magnolol-induced apoptosis, suggesting that p27/Kip1 might play an important role in the regulation of magnolol-induced apoptosis. This notion was further supported by demonstrating that magnolol induced an increase of the caspase activity in U373 in vitro and in vivo, and these effects were abolished by pretransfection of the cell with p27/Kip1 siRNA. To delineate the possible signaling pathways involved in the magnolol-induced increases of p27/Kip1 expression and apoptosis, we found that magnolol (100 μM) increased the levels of phosphorylated cSrc (p-cSrc), p-ERK, p-p38 MAP kinase (p-p38 MAPK), and p-AKT but not p-JNK in U373. Moreover, pretreatment of U373 with a cSrc inhibitor (PP2), a PI3K inhibitor (LY294002), an ERK inhibitor (PD98059), or a p38 MAPK inhibitor (SB203580) but not a JNK inhibitor (SP600125) significantly reduced the magnolol-induced increases of p27/Kip1 protein levels and apoptosis. Taken together, our data suggest that magnolol at a higher concentration of 100 μM induced apopotosis in U373 cells through cSrc-mediated upregulation of p27/Kip1.

  9. Neuroprotective Effects of the Absence of JNK1 or JNK3 Isoforms on Kainic Acid-Induced Temporal Lobe Epilepsy-Like Symptoms.

    PubMed

    de Lemos, Luisa; Junyent, Felix; Camins, Antoni; Castro-Torres, Rubén Darío; Folch, Jaume; Olloquequi, Jordi; Beas-Zarate, Carlos; Verdaguer, Ester; Auladell, Carme

    2018-05-01

    The activation of c-Jun-N-terminal kinases (JNK) pathway has been largely associated with the pathogenesis and the neuronal death that occur in neurodegenerative diseases. Altogether, this justifies why JNKs have become a focus of screens for new therapeutic strategies. The aim of the present study was to identify the role of the different JNK isoforms (JNK1, JNK2, and JNK3) in apoptosis and inflammation after induction of brain damage. To address this aim, we induced excitotoxicity in wild-type and JNK knockout mice (jnk1 -/- , jnk2 -/- , and jnk3 -/- ) via an intraperitoneal injection of kainic acid, an agonist of glutamic-kainate-receptors, that induce status epilepticus.Each group of animals was divided into two treatments: a single intraperitoneal dose of saline solution, used as a control, and a single intraperitoneal dose (30 mg/kg) of kainic acid. Our results reported a significant decrease in neuronal degeneration in the hippocampus of jnk1 -/- and jnk3 -/- mice after kainic acid treatment, together with reduced or unaltered expression of several apoptotic genes compared to WT treated mice. In addition, both jnk1 -/- and jnk3 -/- mice exhibited a reduction in glial reactivity, as shown by the lower expression of inflammatory genes and a reduction of JNK phosphorylation. In addition, in jnk3 -/- mice, the c-Jun phosphorylation was also diminished.Collectively, these findings provide compelling evidence that the absence of JNK1 or JNK3 isoforms confers neuroprotection against neuronal damage induced by KA and evidence, for the first time, the implication of JNK1 in excitotoxicity. Accordingly, JNK1 and/or JNK3 are promising targets for the prevention of cell death and inflammation during epileptogenesis.

  10. Insufficiency of pro-heparin-binding epidermal growth factor-like growth factor shedding enhances hypoxic cell death in H9c2 cardiomyoblasts via the activation of caspase-3 and c-Jun N-terminal kinase.

    PubMed

    Uetani, Teruyoshi; Nakayama, Hironao; Okayama, Hideki; Okura, Takafumi; Higaki, Jitsuo; Inoue, Hirofumi; Higashiyama, Shigeki

    2009-05-01

    Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a cardiogenic and cardiohypertrophic growth factor. ProHB-EGF, a product of the Hb-egf gene and the precursor of HB-EGF, is anchored to the plasma membrane. Its ectodomain region is shed by a disintegrin and metalloproteases (ADAMs) when activated by various stimulations. It has been reported that an uncleavable mutant of Hb-egf, uc-Hb-egf, produces uc-proHB-EGF, which is not cleaved by ADAMs and causes dilation of the heart in knock-in mice. This suggests that the shedding of proHB-EGF is essential for the development and survival of cardiomyocytes: however, the molecular mechanism involved has remained unclear. In this study, we investigated the relationship between uc-proHB-EGF expression and cardiomyocyte survival. Human uc-proHB-EGF was adenovirally introduced into the rat cardiomyoblast cell line H9c2, and the cells were cultured under normoxic and hypoxic conditions. Uc-proHB-EGF-expressing H9c2 cells underwent apoptosis under normoxic conditions, which distinctly increased under hypoxic conditions. Furthermore, we observed an increased Caspase-3 activity, reactive oxygen species accumulation, and an increased c-Jun N-terminal kinase (JNK) activity in the uc-proHB-EGF-expressing H9c2 cells. Treatment of the uc-proHB-EGF transfectants with inhibitors of Caspase-3, reactive oxygen species, and JNK, namely, Z-VAD-fmk, N-acetylcysteine, and SP600125, respectively, significantly reduced hypoxic cell death. These data indicate that insufficiency of proHB-EGF shedding under hypoxic stress leads to cardiomyocyte apoptosis via Caspase-3- and JNK-dependent pathways.

  11. Downregulation of CD9 in Keratinocyte Contributes to Cell Migration via Upregulation of Matrix Metalloproteinase-9

    PubMed Central

    Jiang, Xu-pin; Zhang, Dong-xia; Teng, Miao; Zhang, Qiong; Zhang, Jia-ping; Huang, Yue-sheng

    2013-01-01

    Tetraspanin CD9 has been implicated in various cellular and physiological processes, including cell migration. In our previous study, we found that wound repair is delayed in CD9-null mice, suggesting that CD9 is critical for cutaneous wound healing. However, many cell types, including immune cells, endothelial cells, keratinocytes and fibroblasts undergo marked changes in gene expression and phenotype, leading to cell proliferation, migration and differentiation during wound repair, whether CD9 regulates kerationcytes migration directly remains unclear. In this study, we showed that the expression of CD9 was downregulated in migrating keratinocytes during wound repair in vivo and in vitro. Recombinant adenovirus vector for CD9 silencing or overexpressing was constructed and used to infect HaCaT cells. Using cell scratch wound assay and cell migration assay, we have also demonstrated that downregulation of CD9 promoted keratinocyte migration in vitro, whereas CD9 overexpression inhibited cell migration. Moreover, CD9 inversely regulated the activity and expression of MMP-9 in keratinocytes, which was involved in CD9-regulated keratinocyte migration. Importantly, CD9 silencing-activated JNK signaling was accompanied by the upregulation of MMP-9 activity and expression. Coincidentally, we found that SP600125, a JNK pathway inhibitor, decreased the activity and expression of MMP-9 of CD9-silenced HaCaT cells. Thus, our results suggest that CD9 is downregulated in migrating keratinocytes in vivo and in vitro, and a low level of CD9 promotes keratinocyte migration in vitro, in which the regulation of MMP-9 through the JNK pathway plays an important role. PMID:24147081

  12. Syk-mediated tyrosine phosphorylation of mule promotes TNF-induced JNK activation and cell death.

    PubMed

    Lee, C K; Yang, Y; Chen, C; Liu, J

    2016-04-14

    The transcription factor Miz1 negatively regulates TNF-induced JNK activation and cell death by suppressing TRAF2 K63-polyubiquitination; upon TNF stimulation, the suppression is relieved by Mule/ARF-BP1-mediated Miz1 ubiquitination and subsequent degradation. It is not known how Mule is activated by TNF. Here we report that TNF activates Mule by inducing the dissociation of Mule from its inhibitor ARF. ARF binds to and thereby inhibits the E3 ligase activity of Mule in the steady state. TNF induces tyrosine phosphorylation of Mule, which subsequently dissociates from ARF and becomes activated. Inhibition of Mule phosphorylation by silencing of the Spleen Tyrosine Kinase (Syk) prevents its dissociation from ARF, thereby inhibiting Mule E3 ligase activity and TNF-induced JNK activation and cell death. Our data provides a missing link in TNF signaling pathway that leads to JNK activation and cell death.

  13. A thermostable serralysin inhibitor from marine bacterium Flavobacterium sp. YS-80-122

    NASA Astrophysics Data System (ADS)

    Liang, Pengjuan; Li, Shangyong; Wang, Kun; Wang, Fang; Xing, Mengxin; Hao, Jianhua; Sun, Mi

    2017-06-01

    Serralysin inhibitors have been proposed as potent drugs against many diseases and may help to prevent further development of antibiotic-resistant pathogenic bacteria. In this study, a novel serralysin inhibitor gene, lupI, was cloned from the marine bacterium Flavobacterium sp. YS-80-122 and expressed in Escherichia coli. The deduced serralysin inhibitor, LupI, shows <40% amino acid identity to other reported serralysin inhibitors. Multiple sequence alignment and phylogenetic analysis of LupI with other serralysin inhibitors indicated that LupI was a novel type of serralysin inhibitor. The inhibitory constant for LupI towards its target metalloprotease was 0.64 μmol/L. LupI was thermostable at high temperature, in which 35.6%-90.7% of its inhibitory activity was recovered after treatment at 100°C for 1-60 min followed by incubation at 0°C. This novel inhibitor may represent a candidate drug for the treatment of serralysin-related infections.

  14. A thermostable serralysin inhibitor from marine bacterium Flavobacterium sp. YS-80-122

    NASA Astrophysics Data System (ADS)

    Liang, Pengjuan; Li, Shangyong; Wang, Kun; Wang, Fang; Xing, Mengxin; Hao, Jianhua; Sun, Mi

    2018-03-01

    Serralysin inhibitors have been proposed as potent drugs against many diseases and may help to prevent further development of antibiotic-resistant pathogenic bacteria. In this study, a novel serralysin inhibitor gene, lupI, was cloned from the marine bacterium Flavobacterium sp. YS-80-122 and expressed in Escherichia coli. The deduced serralysin inhibitor, LupI, shows <40% amino acid identity to other reported serralysin inhibitors. Multiple sequence alignment and phylogenetic analysis of LupI with other serralysin inhibitors indicated that LupI was a novel type of serralysin inhibitor. The inhibitory constant for LupI towards its target metalloprotease was 0.64 μmol/L. LupI was thermostable at high temperature, in which 35.6%-90.7% of its inhibitory activity was recovered after treatment at 100°C for 1-60 min followed by incubation at 0°C. This novel inhibitor may represent a candidate drug for the treatment of serralysin-related infections.

  15. Identification and Characterization of a Novel Class of c-Jun N-terminal Kinase Inhibitors

    PubMed Central

    Schepetkin, Igor A.; Kirpotina, Liliya N.; Khlebnikov, Andrei I.; Hanks, Tracey S.; Kochetkova, Irina; Pascual, David W.; Jutila, Mark A.

    2012-01-01

    In efforts to identify novel small molecules with anti-inflammatory properties, we discovered a unique series of tetracyclic indenoquinoxaline derivatives that inhibited lipopolysaccharide (LPS)-induced nuclear factor-κB/activating protein 1 activation. Compound IQ-1 (11H-indeno[1,2-b]quinoxalin-11-one oxime) was found to be a potent, noncytotoxic inhibitor of pro-inflammatory cytokine [interleukin (IL)-1α, IL-1β, IL-6, IL-10, tumor necrosis factor (TNF)-α, interferon-γ, and granulocyte-macrophage colony-stimulating factor] and nitric oxide production by human and murine monocyte/macrophages. Three additional potent inhibitors of cytokine production were identified through further screening of IQ-1 analogs. The sodium salt of IQ-1 inhibited LPS-induced TNF-α and IL-6 production in MonoMac-6 cells with IC50 values of 0.25 and 0.61 μM, respectively. Screening of 131 protein kinases revealed that derivative IQ-3 [11H-indeno[1,2-b]quinoxalin-11-one-O-(2-furoyl)oxime]was a specific inhibitor of the c-Jun N-terminal kinase (JNK) family, with preference for JNK3. This compound, as well as IQ-1 and three additional oxime indenoquinoxalines, were found to be high-affinity JNK inhibitors with nanomolar binding affinity and ability to inhibit c-Jun phosphorylation. Furthermore, docking studies showed that hydrogen bonding interactions of the active indenoquinoxalines with Asn152, Gln155, and Met149 of JNK3 played an important role in enzyme binding activity. Finally, we showed that the sodium salt of IQ-1 had favorable pharmacokinetics and inhibited the ovalbumin-induced CD4+ T-cell immune response in a murine delayed-type hypersensitivity model in vivo. We conclude that compounds with an indenoquinoxaline nucleus can serve as specific small-molecule modulators for mechanistic studies of JNKs as well as a potential leads for the development of anti-inflammatory drugs. PMID:22434859

  16. Activation of ERK and JNK signaling pathways by mycotoxin citrinin in human cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chang, C.-H.; Yu, F.-Y.; Wang, L.-T.

    2009-06-15

    Mycotoxin citrinin (CTN) is commonly found in foods and feeds that are contaminated/inoculated with Penicillium, Aspergillus and Monascus species. The exposure of human embryonic kidney (HEK293) and HeLa cells to CTN resulted in a dose-dependent increase in the phosphorylation of two major mitogen-activated protein kinases (MAPKs), ERK1/2 and JNK. In HEK293 cultures, the administering of CTN increased both the mRNA and protein levels of egr-1, c-fos and c-jun genes; additionally, the ERK1/2 pathway contributed to the upregulation of Egr-1 and c-Fos protein expression. CTN treatment also induced the transcription activity of Egr-1 and AP-1 proteins, as evidenced by luciferase reportermore » assays. Bioinformatic analyses indicated two genes Gadd45{beta} and MMP3 have Egr-1 and AP-1 response elements in their promoters, respectively. Furthermore, co-exposure of HEK293 cells to CTN and MAPK pathway inhibitors demonstrated that CTN increased the levels of Gadd45{beta} mRNA through ERK1/2 signaling pathway and up-regulated the MMP3 transcripts majorly via JNK pathway. Finally, CTN-triggered caspase 3 activity was significantly reduced in the presence of MAPK inhibitors. Our results suggest that CTN positively regulates ERK1/2 and JNK pathways as well as their downstream effectors in human cells; activated MAPK pathways are also involved in CTN-induced apoptosis.« less

  17. Intracellular Networks of the PI3K/AKT and MAPK Pathways for Regulating Toxoplasma gondii-Induced IL-23 and IL-12 Production in Human THP-1 Cells

    PubMed Central

    Choi, In-Wook; Ismail, Hassan Ahmed Hassan Ahmed; Zhou, Wei; Cha, Guang-Ho; Zhou, Yu; Yuk, Jae-Min; Jo, Eun-Kyeong; Lee, Young-Ha

    2015-01-01

    Interleukin (IL)-23 and IL-12 are closely related in structure, and these cytokines regulate both innate and adaptive immunity. However, the precise signaling networks that regulate the production of each in Toxoplasma gondii-infected THP-1 monocytic cells, particularly the PI3K/AKT and MAPK signaling pathways, remain unknown. In the present study, T. gondii infection upregulated the expression of IL-23 and IL-12 in THP-1 cells, and both cytokines increased with parasite dose. IL-23 secretion was strongly inhibited by TLR2 monoclonal antibody (mAb) treatment in a dose-dependent manner and by TLR2 siRNA transfection, whereas IL-12 secretion was strongly inhibited by TLR4 mAb treatment dose-dependently and by TLR4 siRNA transfection. IL-23 production was dose-dependently inhibited by the PI3K inhibitors LY294002 and wortmannin, whereas IL-12 production increased dose-dependently. THP-1 cells exposed to live T. gondii tachyzoites underwent rapid p38 MAPK, ERK1/2 and JNK activation. IL-23 production was significantly upregulated by the p38 MAPK inhibitor SB203580 dose-dependently, whereas pretreatment with 10 μM SB203580 significantly downregulated IL-12 production. ERK1/2 inhibition by PD98059 was significantly downregulated IL-23 production but upregulated IL-12 production. JNK inhibition by SP600125 upregulated IL-23 production, but IL-12 production was significantly downregulated dose-dependently. T. gondii infection resulted in AKT activation, and AKT phosphorylation was inhibited dose-dependently after pretreatment with PI3K inhibitors. In T. gondii-infected THP-1 cells, ERK1/2 activation was regulated by PI3K; however, the phosphorylation of p38 MAPK and JNK was negatively modulated by the PI3K signaling pathway. Collectively, these results indicate that IL-23 production in T. gondii-infected THP-1 cells was regulated mainly by TLR2 and then by PI3K and ERK1/2; however, IL-12 production was mainly regulated by TLR4 and then by p38 MAPK and JNK. Our findings

  18. 17β-Estradiol on the Expression of G-Protein Coupled Estrogen Receptor (GPER/GPR30) Mitophagy, and the PI3K/Akt Signaling Pathway in ATDC5 Chondrocytes In Vitro

    PubMed Central

    Fan, Dong-xiao; Yang, Xu-hao; Li, Yi-nan

    2018-01-01

    Background Osteoarthritis is a progressive inflammatory joint disease resulting in damage to articular cartilage. G-protein coupled estrogen receptor (GPER/GPR30) activates cell signaling in response to 17β-estradiol, which can be blocked by the GPR30 agonist, G15, an analog of G-1. The aims of this study were to investigate the effects of 17β-estradiol on the expression of G-protein coupled estrogen receptor (GPER/GPR30) on mitophagy and the PI3K/Akt signaling pathway in ATDC5 chondrocytes in vitro. Material/Methods Cultured ATDC5 chondrocytes were treated with increasing concentrations of 17β-estradiol with and without G15, p38 inhibitor (SB203580), JNK inhibitor (SP600125), PI3K inhibitor (LY294002, S1737), and mTOR inhibitor (S1842). Expression of GPER/GPR30 and components of the PI3K/Akt pathway in cultured ATDC5 chondrocytes were detected by immunofluorescence (IF) staining, Western blot, and real-time polymerase chain reaction (RT-PCR). Transmission electron microscopy (TEM) and IF were used to detect mitophagosomes. Expression of LC-3, LAMP2, TOM20, Hsp60, p-Akt, p-mTOR, p-p38, and p-JNK was investigated by Western blot. Proliferation and viability of the ATDC5 chondrocytes were determined using BrdU and MTT assays. Results In 17β-estradiol-treated ATDC5 chondrocytes, increased expression of GPER/GPR30 was found, but fewer mitophagosomes were observed, and decreased numbers of TOM20-positive granules were co-localized with decreased LAMP2 and increased expression levels of TOM20, Hsp60, p-Akt, and p-mTOR, and reduced expression of LC3-II, were found. In 17β-estradiol-treated ATDC5 chondrocytes, the proliferation and viability of the 17β-estradiol-treated ATDC5 chondrocytes were significantly elevated. Conclusions Treatment with 17β-estradiol protected ATDC5 chondrocytes against mitophagy via the GPER/GPR30 and the PI3K/Akt signaling pathway. PMID:29608013

  19. Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye.

    PubMed

    Wu, Yue; Zhuang, Yuan; Han, Min; Xu, Tian; Deng, Kejing

    2009-10-20

    Programmed cell death, or apoptosis, is a fundamental physiological process during normal development or in pathological conditions. The activation of apoptosis can be elicited by numerous signalling pathways. Ras is known to mediate anti-apoptotic signals by inhibiting Hid activity in the Drosophila eye. Here we report the isolation of a new loss-of-function ras allele, rasKP, which causes excessive apoptosis in the Drosophila eye. This new function is likely to be mediated through the JNK pathway since the inhibition of JNK signalling can significantly suppress rasKP-induced apoptosis, whereas the removal of hid only weakly suppresses the phenotype. Furthermore, the reduction of JNK signalling together with the expression of the baculovirus caspase inhibitor p35, which blocks Hid activity, strongly suppresses the rasKP cell death. In addition, we find a strong correlation between rasKP-induced apoptosis in the eye disc and the activation of JNK signalling. In the Drosophila eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression.

  20. Thorium induced cytoproliferative effect in human liver cell HepG2: role of insulin-like growth factor 1 receptor and downstream signaling.

    PubMed

    Ali, Manjoor; Kumar, Amit; Pandey, Badri N

    2014-03-25

    Thorium-232 ((232)Th), a naturally-occurring actinide has gained significant attention due to its immense potential as a nuclear fuel for advanced reactors. Understanding the biological effects of (232)Th would significantly impact its efficient utilization with adequate health protection. Humans administered with (232)Th (thorotrast patients) or experimental animal models showed that liver is one of the major sites of (232)Th accumulation. Present study reports cellular effects of (232)Th-nitrate in a human-derived liver cell (HepG2). Results showed that the low concentration of (232)Th (0.1-10 μM) induced proliferation of HepG2 cells which was inhibited by the pre-treatment of cells with neutralizing antibody against insulin-like growth factor 1 receptor (IGF-1R). Consistently, (232)Th treatment was found to increase the phosphorylated level of IGF-1R-associated molecule, IRS1 which serves to activate PI3K and MAPK signaling pathways. Pre-treatment with specific inhibitors of PI3K (LY294002) or JNK-MAPK (SP600125) significantly abrogated the cytoproliferative effect of (232)Th. Immunofluorescence analysis showed increased levels of phospho-Akt and phospho-JNK, downstream kinases of IGF-1R, in (232)Th-treated HepG2 cells suggesting the role of IGF-1R-mediated signaling in (232)Th-stimulated cell proliferation. The cell cycle analysis showed that (232)Th increased S and G2-M cell fractions concomitant to the increase of cyclin-E level. Thus, the present investigation highlights the role of IGF-1R-mediated signaling in the cytoproliferative effect of (232)Th in human liver cells at low concentration. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. LPS Increases 5-LO Expression on Monocytes via an Activation of Akt-Sp1/NF-κB Pathways.

    PubMed

    Lee, Seung Jin; Seo, Kyo Won; Kim, Chi Dae

    2015-05-01

    5-Lipoxygenase (5-LO) plays a pivotal role in the progression of atherosclerosis. Therefore, this study investigated the molecular mechanisms involved in 5-LO expression on monocytes induced by LPS. Stimulation of THP-1 monocytes with LPS (0~3 µg/ml) increased 5-LO promoter activity and 5-LO protein expression in a concentration-dependent manner. LPS-induced 5-LO expression was blocked by pharmacological inhibition of the Akt pathway, but not by inhibitors of MAPK pathways including the ERK, JNK, and p38 MAPK pathways. In line with these results, LPS increased the phosphorylation of Akt, suggesting a role for the Akt pathway in LPS-induced 5-LO expression. In a promoter activity assay conducted to identify transcription factors, both Sp1 and NF-κB were found to play central roles in 5-LO expression in LPS-treated monocytes. The LPS-enhanced activities of Sp1 and NF-κB were attenuated by an Akt inhibitor. Moreover, the LPS-enhanced phosphorylation of Akt was significantly attenuated in cells pretreated with an anti-TLR4 antibody. Taken together, 5-LO expression in LPS-stimulated monocytes is regulated at the transcriptional level via TLR4/Akt-mediated activations of Sp1 and NF-κB pathways in monocytes.

  2. Interleukin-1 Acts via the JNK-2 Signaling Pathway to Induce Aggrecan Degradation by Human Chondrocytes.

    PubMed

    Ismail, Heba M; Yamamoto, Kazuhiro; Vincent, Tonia L; Nagase, Hideaki; Troeberg, Linda; Saklatvala, Jeremy

    2015-07-01

    Aggrecan enables articular cartilage to bear load and resist compression. Aggrecan loss occurs early in osteoarthritis and rheumatoid arthritis and can be induced by inflammatory cytokines such as interleukin-1 (IL-1). IL-1 induces cleavage of specific aggrecans characteristic of the ADAMTS proteinases. The aim of this study was to identify the intracellular signaling pathways by which IL-1 causes aggrecan degradation by human chondrocytes and to investigate how aggrecanase activity is controlled by chondrocytes. We developed a cell-based assay combining small interfering RNA (siRNA)-induced knockdown with aggrecan degradation assays. Human articular chondrocytes were overlaid with bovine aggrecan after transfection with siRNAs against molecules of the IL-1 signaling pathway. After IL-1 stimulation, released aggrecan fragments were detected with AGEG and ARGS neoepitope antibodies. Aggrecanase activity and tissue inhibitor of metalloproteinases 3 levels were measured by enzyme-linked immunosorbent assay. Low-density lipoprotein receptor-related protein 1 (LRP-1) shedding was analyzed by Western blotting. ADAMTS-5 is a major aggrecanase in human chondrocytes, regulating aggrecan degradation in response to IL-1. The tumor necrosis factor receptor-associated 6 (TRAF-6)/transforming growth factor β-activated kinase 1 (TAK-1)/MKK-4 signaling axis is essential for IL-1-induced aggrecan degradation, while NF-κB is not. Of the 3 MAPKs (ERK, p38, and JNK), only JNK-2 showed a significant role in aggrecan degradation. Chondrocytes constitutively secreted aggrecanase, which was continuously endocytosed by LRP-1, keeping the extracellular level of aggrecanase low. IL-1 induced aggrecanase activity in the medium in a JNK-2-dependent manner, possibly by reducing aggrecanase endocytosis, because IL-1 caused JNK-2-dependent shedding of LRP-1. The signaling axis TRAF-6/TAK-1/MKK-4/JNK-2 mediates IL-1-induced aggrecanolysis. The level of aggrecanase is controlled by its

  3. Gremlin 2 promotes differentiation of embryonic stem cells to atrial fate by activation of the JNK signaling pathway

    PubMed Central

    Tanwar, Vineeta; Bylund, Jeffery B.; Hu, Jianyong; Yan, Jingbo; Walthall, Joel M.; Mukherjee, Amrita; Heaton, William H.; Wang, Wen-Der; Potet, Franck; Rai, Meena; Kupershmidt, Sabina; Knapik, Ela W.; Hatzopoulos, Antonis K.

    2014-01-01

    The Bone Morphogenetic Protein antagonist Gremlin 2 (Grem2) is required for atrial differentiation and establishment of cardiac rhythm during embryonic development. A human Grem2 variant has been associated with familial atrial fibrillation, suggesting that abnormal Grem2 activity causes arrhythmias. However, it is not known how Grem2 integrates into signaling pathways to direct atrial cardiomyocyte differentiation. Here, we demonstrate that Grem2 expression is induced concurrently with the emergence of cardiovascular progenitor cells during differentiation of mouse embryonic (ES) stem cells. Grem2 exposure enhances the cardiogenic potential of ES cells by ~20–120 fold, preferentially inducing genes expressed in atrial myocytes such as Myl7, Nppa and Sarcolipin. We show that Grem2 acts upstream to upregulate pro-atrial transcriptional factors CoupTFII and Hey1 and downregulate atrial fate repressors Irx4 and Hey2. The molecular phenotype of Grem2-induced atrial cardiomyocytes was further supported by induction of ion channels encoded by Kcnj3, Kcnj5, and Cacna1D genes and establishment of atrial-like action potentials shown by electrophysiological recordings. We show that promotion of atrial-like cardiomyocyte is specific to the Gremlin subfamily of BMP antagonists. Grem2 pro-atrial differentiation activity is conveyed by non-canonical BMP signaling through phosphorylation of JNK and can be reversed by specific JNK inhibitors, but not by dorsomorphin, an inhibitor of canonical BMP signaling. Taken together, our data provide novel mechanistic insights into atrial cardiomyocyte differentiation from pluripotent stem cells and will assist the development of future approaches to study and treat arrhythmias. PMID:24648383

  4. Extract from Periostracum cicadae Inhibits Oxidative Stress and Inflammation Induced by Ultraviolet B Irradiation on HaCaT Keratinocytes

    PubMed Central

    Tsen, Jen-Horng; Yen, Hsuan; Yang, Ting-Ya

    2017-01-01

    Periostracum cicadae is widely used for the treatment of skin diseases such as eczema, pruritus, and itching. The current study sought to evaluate the effect of P. cicadae extract on ultraviolet B (UVB) irradiation and identify the mechanisms involved. Photodamage-protective activity of P. cicadae extracts against oxidative challenge was screened using HaCaT keratinocytes. P. cicadae extracts did not affect cell viability but decreased reactive oxygen species (ROS) production. The extract attenuates the expression of interleukin-6 (IL-6), matrix metalloproteinase-2 (MMP-2), and MMP-9 in UVB-treated HaCaT cells. Also, P. cicadae abrogated UVB-induced activation of NF-κB, p53, and activator protein-1 (AP-1). The downmodulation of IL-6 by P. cicadae was inhibited by the p38 inhibitor (SB203580) or JNK inhibitor (SP600125). Moreover, the extract attenuated the expression of NF-κB and induced thrombomodulin in keratinocytes and thereby effectively downregulated inflammatory responses in the skin. The nuclear accumulation and expression of NF-E2-related factor (Nrf2) were increased by P. cicadae treatment. Furthermore, treatment with P. cicadae remarkably ameliorated the skin's structural damage induced by irradiation. This study demonstrates that P. cicadae may protect skin cells against oxidative insult by modulating ROS concentration, IL-6, MMPs generation, antioxidant enzymes activity, and cell signaling pathways. PMID:28465707

  5. Ribes nigrum L. Prevents UVB-mediated Photoaging in Human Dermal Fibroblasts: Potential Antioxidant and Antiinflammatory Activity.

    PubMed

    Li, Lu; Hwang, Eunson; Ngo, Hien T T; Seo, Seul A; Lin, Pei; Gao, Wei; Liu, Ying; Yi, Tae-Hoo

    2018-05-16

    Black currants (Ribes nigrum L, RN) are known as a "super fruit" to possess for their many potential health benefits such as the alleviation of oxidative stress-related disorders. However, little skin photoaging-related research has been done on the use of this agent. In the present study, we investigated the protective effects of RN in UVB-irradiated human dermal fibroblasts (NHDFs). RN treatment in UVB-irradiated skin models alleviated UVB-mediated photoaging through several mechanisms: Treatment with RN downregulated MAPK-related signaling models, such as those of activation protein 1 (AP-1) and nuclear factor kappa B (NF-κB). In addition, phase II gene heme oxygenase-1 (HO-1) was modulated by the increase in nuclear factor erythroid 2-related factor 2 (Nrf2) in the nuclear, and finally, transforming growth factor TGF-β was upregulated in vitro. Further study indicated that UVB-induced production of MMP-1 and IL-6 could be inhibited by PD 98059 (an inhibitor of ERK) and SP600125 (an inhibitor of JNK). Thus, RN improved the expression of type I procollagen and inhibited UVB-induced MMP-1 and IL-6 secretion through inactivating MAPK cascades. Therefore, RN is a suitable target for further investigation as an antiphotoaging agent and may have applications in the skincare industry. © 2018 The American Society of Photobiology.

  6. Down-modulation of erbB2 activity is necessary but not enough in the differentiation of 3T3-L1 preadipocytes.

    PubMed

    Pagano, Eleonora; Coso, Omar; Calvo, Juan Carlos

    2008-05-01

    The high incidence of obesity-related pathologies, led to the study of the mechanisms involved in preadipose cell proliferation and differentiation. Here, we demonstrate that modulation of erbB2, plays a fundamental role during proliferation and adipogenic induction of preadipocytes. Using 3T3-L1 cells as model, we demonstrate that EGF (10 nM, 5 min) in addition to stimulate receptor tyrosine phosphorylation of both erbB2 and EGFR, is able to induce the heterodimer erbB2-EGFR. We treated proliferating 3T3-L1 cells with two inhibitors, AG 825 (IC(50) 0.35 microM, 54 times more selective for erbB2 than for EGFR, IC(50) 19 microM), and AG 879 (IC(50) of 1 microM for erbB2 versus 500 microM for EGFR). We found that both inhibited the proliferation on a dose-dependent basis, reaching a 30% maximal inhibition at 100 microM (P < 0.001) for AG825, and a 20% maximal inhibition at 10 microM (P < 0.001) for AG 879. These results involve erbB2 in 3T3-L1 proliferation. When studying the differentiation process, we found that the action of MIX-Dexa immediately activates MEK, JNK and p38 kinases. We observed that PD98059 and SP600125 (MEK-ERK and JNK inhibitors, respectively) added 1 h prior to the MIX-Dexa induction produced a decrease in erbB2 expression after 6 h, which is even greater than the one produced by the inducers, MIX-Dexa. This work supports erbB2 as a key factor in 3T3-L1 adipogenesis, acting mostly and not only during the proliferative phase but also during the differentiation through modulation of both its expression and activity.

  7. Parkin Knockout Inhibits Neuronal Development via Regulation of Proteasomal Degradation of p21

    PubMed Central

    Park, Mi Hee; Lee, Hwa-Jeong; Lee, Hye Lim; Son, Dong Ju; Ju, Jung Hoon; Hyun, Byung Kook; Jung, Sung Hee; Song, Ju-Kyoung; Lee, Dong Hun; Hwang, Chul Ju; Han, Sang Bae; Kim, Sanghyeon; Hong, Jin Tae

    2017-01-01

    PARK2 encodes for the E3 ubiquitin ligase parkin and is implicated in the development of Parkinson's disease (PD). Although the neuroprotective role of parkin is well known, the mechanism of PARK2's function in neural stem differentiation has not yet been thoroughly studied. Co-expressions network analysis showed that synaptosomal-associated protein 25 (SNAP-25) and brain-derived neurotrophic factor (BDNF) were positively correlated with parkin, but negatively correlated with p21 in human patient brain. We investigated a link between the ubiquitin E3 ligase parkin and proteasomal degradation of p21 for the control of neural stem cell differentiation. We found that the neurogenesis was lowered in PARK2 knockout (KO) mice compared with non-tg mice. Expression of the marker protein for neural cell differentiation such as class III beta tubulin (TUBBIII), glial fibrillary acidic protein (GFAP) and neurofilament, as well as SNAP25 and BDNF, was down regulated in PARK2 KO mice. Associated with the loss of differentiation function, p21 protein was highly accumulated in the neural stem cells of PARK2 KO mice. We discovered that p21 directly binds with parkin and is ubiquitinated by parkin which resulted in the loss of cell differentiation ability. Introduction of p21 shRNA in PARK2 KO mice significantly rescued the differentiation efficacy as well as SNAP25 and BDNF expression. c-Jun N-terminal kinase (JNK) pathway is implicated in neurogenesis and p21 degradation. We also defined the decreased p21 ubiquitination and differentiation ability were reversed after treatment with JNK inhibitor, SP600125 in PARK2 KO mice derived neural stem cells. Thus, the present study indicated that parkin knockout inhibits neural stem cell differentiation by JNK-dependent proteasomal degradation of p21. PMID:28656059

  8. Parkin Knockout Inhibits Neuronal Development via Regulation of Proteasomal Degradation of p21.

    PubMed

    Park, Mi Hee; Lee, Hwa-Jeong; Lee, Hye Lim; Son, Dong Ju; Ju, Jung Hoon; Hyun, Byung Kook; Jung, Sung Hee; Song, Ju-Kyoung; Lee, Dong Hun; Hwang, Chul Ju; Han, Sang Bae; Kim, Sanghyeon; Hong, Jin Tae

    2017-01-01

    PARK2 encodes for the E3 ubiquitin ligase parkin and is implicated in the development of Parkinson's disease (PD). Although the neuroprotective role of parkin is well known, the mechanism of PARK2's function in neural stem differentiation has not yet been thoroughly studied. Co-expressions network analysis showed that synaptosomal-associated protein 25 (SNAP-25) and brain-derived neurotrophic factor (BDNF) were positively correlated with parkin, but negatively correlated with p21 in human patient brain. We investigated a link between the ubiquitin E3 ligase parkin and proteasomal degradation of p21 for the control of neural stem cell differentiation. We found that the neurogenesis was lowered in PARK2 knockout (KO) mice compared with non-tg mice. Expression of the marker protein for neural cell differentiation such as class III beta tubulin (TUBBIII), glial fibrillary acidic protein (GFAP) and neurofilament, as well as SNAP25 and BDNF, was down regulated in PARK2 KO mice. Associated with the loss of differentiation function, p21 protein was highly accumulated in the neural stem cells of PARK2 KO mice. We discovered that p21 directly binds with parkin and is ubiquitinated by parkin which resulted in the loss of cell differentiation ability. Introduction of p21 shRNA in PARK2 KO mice significantly rescued the differentiation efficacy as well as SNAP25 and BDNF expression. c-Jun N-terminal kinase (JNK) pathway is implicated in neurogenesis and p21 degradation. We also defined the decreased p21 ubiquitination and differentiation ability were reversed after treatment with JNK inhibitor, SP600125 in PARK2 KO mice derived neural stem cells. Thus, the present study indicated that parkin knockout inhibits neural stem cell differentiation by JNK-dependent proteasomal degradation of p21.

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Huang-Joe; Division of Cardiology, Department of Medicine, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan; Lo, Wan-Yu

    Patients with paclitaxel-eluting stents are concerned with stent thrombosis caused by premature discontinuation of dual antiplatelet therapy or clopidogrel resistance. This study investigates the effect of (-)-epigallocatechin-3-gallate (EGCG) on the expression of thrombin/paclitaxel-induced endothelial tissue factor (TF) expressions in human aortic endothelial cells (HAECs). EGCG was nontoxic to HAECs at 6 h up to a concentration of 25 {mu}mol/L. At a concentration of 25 {mu}mol/L, EGCG pretreatment potently inhibited both thrombin-stimulated and thrombin/paclitaxel-stimulated endothelial TF protein expression. Thrombin and thrombin/paclitaxel-induced 2.6-fold and 2.9-fold increases in TF activity compared with the control. EGCG pretreatment caused a 29% and 38% decrease inmore » TF activity on thrombin and thrombin/paclitaxel treatment, respectively. Real-time polymerase chain reaction (PCR) showed that thrombin and thrombin/paclitaxel-induced 3.0-fold and 4.6-fold TF mRNA expressions compared with the control. EGCG pretreatment caused an 82% and 72% decrease in TF mRNA expression on thrombin and thrombin/paclitaxel treatment, respectively. The c-Jun terminal NH2 kinase (JNK) inhibitor SP600125 reduced thrombin/paclitaxel-induced TF expression. Furthermore, EGCG significantly inhibited the phosphorylation of JNK to 49% of thrombin/paclitaxel-stimulated HAECs at 60 min. Immunofluorescence assay did not show an inhibitory effect of EGCG on P65 NF-{kappa}B nuclear translocation in the thrombin/paclitaxel-stimulated endothelial cells. In conclusion, EGCG can inhibit TF expression in thrombin/paclitaxel-stimulated endothelial cells via the inhibition of JNK phosphorylation. The unique property of EGCG may be used to develop a new drug-eluting stent by co-coating EGCG and paclitaxel.« less

  10. Endotoxin-activated microglia injure brain derived endothelial cells via NF-κB, JAK-STAT and JNK stress kinase pathways

    PubMed Central

    2011-01-01

    Background We previously showed that microglia damage blood brain barrier (BBB) components following ischemic brain insults, but the underlying mechanism(s) is/are not well known. Recent work has established the contribution of toll-like receptor 4 (TLR4) activation to several brain pathologies including ischemia, neurodegeneration and sepsis. The present study established the requirement of microglia for lipopolysaccharide (LPS) mediated endothelial cell death, and explored pathways involved in this toxicity. LPS is a classic TLR4 agonist, and is used here to model aspects of brain conditions where TLR4 stimulation occurs. Methods/Results In monocultures, LPS induced death in microglia, but not brain derived endothelial cells (EC). However, LPS increased EC death when cocultured with microglia. LPS led to nitric oxide (NO) and inducible NO synthase (iNOS) induction in microglia, but not in EC. Inhibiting microglial activation by blocking iNOS and other generators of NO or blocking reactive oxygen species (ROS) also prevented injury in these cocultures. To assess the signaling pathway(s) involved, inhibitors of several downstream TLR-4 activated pathways were studied. Inhibitors of NF-κB, JAK-STAT and JNK/SAPK decreased microglial activation and prevented cell death, although the effect of blocking JNK/SAPK was rather modest. Inhibitors of PI3K, ERK, and p38 MAPK had no effect. Conclusions We show that LPS-activated microglia promote BBB disruption through injury to endothelial cells, and the specific blockade of JAK-STAT, NF-κB may prove to be especially useful anti-inflammatory strategies to confer cerebrovascular protection. PMID:21385378

  11. A single polymorphism in HIV-1 subtype C SP1 is sufficient to confer natural resistance to the maturation inhibitor bevirimat.

    PubMed

    Lu, Wuxun; Salzwedel, Karl; Wang, Dan; Chakravarty, Suvobrata; Freed, Eric O; Wild, Carl T; Li, Feng

    2011-07-01

    3-O-(3',3'-Dimethylsuccinyl) betulinic acid (DSB), also known as PA-457, bevirimat (BVM), or MPC-4326, is a novel HIV-1 maturation inhibitor. Unlike protease inhibitors, BVM blocks the cleavage of the Gag capsid precursor (CA-SP1) to mature capsid (CA) protein, resulting in the release of immature, noninfectious viral particles. Despite the novel mechanism of action and initial progress made in small-scale clinical trials, further development of bevirimat has encountered unexpected challenges, because patients whose viruses contain genetic polymorphisms in the Gag SP1 (positions 6 to 8) protein do not generally respond well to BVM treatment. To better define the role of amino acid residues in the HIV-1 Gag SP1 protein that are involved in natural polymorphisms to confer resistance to the HIV-1 maturation inhibitor BVM, a series of Gag SP1 chimeras involving BVM-sensitive (subtype B) and BVM-resistant (subtype C) viruses was generated and characterized for sensitivity to BVM. We show that SP1 residue 7 of the Gag protein is a primary determinant of SP1 polymorphism-associated drug resistance to BVM.

  12. ROCK mediates phorbol ester-induced apoptosis in prostate cancer cells via p21Cip1 up-regulation and JNK.

    PubMed

    Xiao, Liqing; Eto, Masumi; Kazanietz, Marcelo G

    2009-10-23

    It is established that androgen-dependent prostate cancer cells undergo apoptosis upon treatment with phorbol esters and related analogs, an effect primarily mediated by PKCdelta. Treatment of LNCaP prostate cancer cells with phorbol 12-myristate 13-acetate (PMA) causes a strong and sustained activation of RhoA and its downstream effector ROCK (Rho kinase) as well as the formation of stress fibers. These effects are impaired in cells subjected to PKCdelta RNA interference depletion. Functional studies revealed that expression of a dominant negative RhoA mutant or treatment with the ROCK inhibitor Y-27632 inhibits the apoptotic effect of PMA in LNCaP cells. Remarkably, the cytoskeleton inhibitors cytochalasin B and blebbistatin blocked not only PMA-induced apoptosis but also the activation of JNK, a mediator of the cell death effect by the phorbol ester. In addition, we found that up-regulation of the cell cycle inhibitor p21(Cip1) is required for PMA-induced apoptosis and that inhibitors of ROCK or the cytoskeleton organization prevent p21(Cip1) induction. Real time PCR analysis and reporter gene assay revealed that PMA induces p21(Cip1) transcriptionally in a ROCK- and cytoskeleton-dependent manner. p21(Cip1) promoter analysis revealed that PMA induction is dependent on Sp1 elements in the p21(Cip1) promoter but independent of p53. Taken together, our studies implicate ROCK-mediated up-regulation of p21(Cip1) and the cytoskeleton in PKCdelta-dependent apoptosis in prostate cancer cells.

  13. Induction of HO-1 by carbon monoxide releasing molecule-2 attenuates thrombin-induced COX-2 expression and hypertrophy in primary human cardiomyocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chien, Peter Tzu-Yu; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan; Lin, Chih-Chung

    Carbon monoxide (CO) is one of the cytoprotective byproducts of heme oxygenase (HO)-1 and exerts anti-inflammatory action in various models. However, the detailed mechanisms underlying CO-induced HO-1 expression in primary human cardiomyocytes remain largely unidentified. We used primary left ventricle myocytes as a model and applied CO releasing molecule (CORM)-2 to investigate the relationship of CO and HO-1 expression. We herein used Western blot, real-time PCR, promoter activity and EIA to investigate the role of HO-1 expression protecting against thrombin-mediated responses. We found that thrombin-induced COX-2 expression, PGE{sub 2} release and cardiomyocyte hypertrophy markers (increase in ANF/BNP, α-actin expression andmore » cell surface area) was attenuated by pretreatment with CORM-2 which was partially reversed by hemoglobin (Hb) or ZnPP (an inhibitor of HO-1 activity), suggesting that HO-1/CO system may be of clinical importance to ameliorate heart failure through inhibition of inflammatory responses. CORM-2-induced HO-1 protein expression, mRNA and promoter was attenuated by pretreatment with the inhibitors of Pyk2 (PF431396), PDGFR (AG1296), PI3K (LY294002), Akt (SH-5), p38 (SB202530), JNK1/2 (SP600125), FoxO1 (AS1842856) and Sp1 (mithramycin A). The involvement of these signaling components was further confirmed by transfection with respective siRNAs, consistent with those of pharmacological inhibitors. These results suggested that CORM-2-induced HO-1 expression is mediated through a Pyk2/PDGFR/PI3K/Akt/FoxO1/Sp1-dependent manner and exerts a cytoprotective effect in human cardiomyocytes. - Graphical abstract: In summary, CORM-2 treatment induces Pyk2 transactivated PDGFR, which induces PI3K/Akt/MAPK activation, and then recruits Sp1/Foxo1 transcriptional factors to regulate HO-1 gene expression in primary human cardiomyocytes. - Highlights: • CORM-2 induces HO-1 expression. • Pyk2-dependent PDGFR activates PI3K/Akt/MAPK pathway in CORM-2

  14. Curcumol suppresses RANKL-induced osteoclast formation by attenuating the JNK signaling pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yu, Mingxiang, E-mail: yu.mingxiang@zs-hospital.sh.cn; Chen, Xianying; Lv, Chaoyang

    Highlights: • Curcumol suppresses osteoclasts differentiation in vitro. • Curcumol impairs JNK/AP-1 signaling pathway. • Curcumol may be used for treating osteoclast related diseases. - Abstract: Osteoclasts, derived from hemopoietic progenitors of the monocyte/macrophage lineage, have a unique role in bone resorption, and are considered a potential therapeutic target in the treatment of such pathologic bone diseases as osteoporosis, rheumatoid arthritis, and periodontitis. In the present study, we demonstrate that curcumol, one of the major components of the essential oil of Rhizoma Curcumae, exhibits an inhibitory effect on receptor activator of nuclear factor kappaB ligand (RANKL)-induced osteoclast differentiation with bothmore » bone marrow-derived macrophages and RAW264.7 cells in a dose-dependent manner. In addition, RANKL-induced mRNA expression of osteoclast-specific genes, such as tartrate-resistant acid phosphatase, calcitonin receptor, and cathepsin K, is prominently reduced in the presence of curcumol. Furthermore, the molecular mechanism of action was investigated, and curcumol inhibited osteoclastogenesis by specifically impairing RANKL-induced c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) signaling, which was further identified in rescue studies by means of anisomycin, a JNK signaling-specific activator. Taken together, these findings suggest that curcumol suppresses RANKL-induced osteoclast differentiation through the JNK/AP-1 signaling pathway, and may be useful as a therapeutic treatment for bone resorption-associated diseases.« less

  15. Synthesis and optimization of thiadiazole derivatives as a novel class of substrate competitive c-Jun N-terminal kinase inhibitors

    PubMed Central

    De, Surya K.; Chen, Vida; Stebbins, John L.; Chen, Li-Hsing; Cellitti, Jason F.; Machleidt, Thomas; Barile, Elisa; Riel-Mehan, Megan; Dahl, Russell; Yang, Li; Emdadi, Aras; Murphy, Ria; Pellecchia, Maurizio

    2009-01-01

    A series of thiadiazole derivatives has been designed as potential allosteric, substrate competitive inhibitors of the protein kinase JNK. We report on the synthesis, characterization and evaluation of a series of compounds that resulted in the identification of potent and selective JNK inhibitors targeting its JIP-1 docking site. PMID:20045647

  16. The mechanism by which MEK/ERK regulates JNK and p38 activity in polyamine depleted IEC-6 cells during apoptosis

    PubMed Central

    Bavaria, Mitul N.; Jin, Shi; Ray, Ramesh M.; Johnson, Leonard R.

    2014-01-01

    Polyamine-depletion inhibited apoptosis by activating ERK1/2, while, preventing JNK1/2 activation. MKP-1 knockdown by SiRNA increased ERK1/2, JNK1/2, and p38 phosphorylation and apoptosis. Therefore, we predicted that polyamines might regulate MKP1 via MEK/ERK and thereby apoptosis. We examined the role of MEK/ERK in the regulation of MKP1 and JNK, and p38 activities and apoptosis. Inhibition of MKP-1 activity with a pharmacological inhibitor, sanguinarine (SA), increased JNK1/2, p38, and ERK1/2 activities without causing apoptosis. However, pre-activation of these kinases by SA significantly increased camptothecin (CPT)-induced apoptosis suggesting different roles for MAPKs during survival and apoptosis. Inhibition of MEK1 activity prevented the expression of MKP-1 protein and augmented CPT-induced apoptosis, which correlated with increased activities of JNK1/2, caspases, and DNA fragmentation. Polyamine depleted cells had higher levels of MKP-1 protein and decreased JNK1/2 activity and apoptosis. Inhibition of MEK1 prevented MKP-1 expression and increased JNK1/2 and apoptosis. Phospho-JNK1/2, phospho-ERK2, MKP-1, and the catalytic subunit of protein phosphatase 2A (PP2Ac) formed a complex in response to TNF/CPT. Inactivation of PP2Ac had no effect on the association of MKP-1 and JNK1. However, inhibition of MKP-1 activity decreased the formation of the MKP-1, PP2Ac and JNK complex. Following inhibition by SA, MKP-1 localized in the cytoplasm, while basal and CPT-induced MKP-1 remained in the nuclear fraction. These results suggest that nuclear MKP-1 translocates to the cytoplasm, binds phosphorylated JNK and p38 resulting in dephosphorylation and decreased activity. Thus, MEK/ERK activity controls the levels of MKP-1 and, thereby, regulates JNK activity in polyamine-depleted cells. PMID:24253595

  17. Jellyfish collagen stimulates production of TNF-α and IL-6 by J774.1 cells through activation of NF-κB and JNK via TLR4 signaling pathway.

    PubMed

    Putra, Agus Budiawan Naro; Nishi, Kosuke; Shiraishi, Ryusuke; Doi, Mikiharu; Sugahara, Takuya

    2014-03-01

    We previously reported that jellyfish collagen stimulates both the acquired and innate immune responses. In the acquired immune response, jellyfish collagen enhanced immunoglobulin production by lymphocytes in vitro and in vivo. Meanwhile, in the innate immune response jellyfish collagen promoted cytokine production and phagocytotic activity of macrophages. The facts that jellyfish collagen plays several potential roles in stimulating cytokine production by macrophages have further attracted us to uncover its mechanisms. We herein describe that the cytokine production-stimulating activity of jellyfish collagen was canceled by a Toll-like receptor 4 (TLR4) inhibitor. Moreover, jellyfish collagen stimulated phosphorylation of inhibitor of κBα (IκBα), promoted the translocation of nucleus factor-κB (NF-κB), and activated c-Jun N-terminal kinase (JNK). A JNK inhibitor also abrogated the cytokine production-stimulating activity of jellyfish collagen. These results suggest that jellyfish collagen may facilitate cytokine production by macrophages through activation of NF-κB and JNK via the TLR4 signaling pathways. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Inhibition of protein kinase C α/βII and activation of c-Jun NH2-terminal kinase mediate glycyrrhetinic acid induced apoptosis in non-small cell lung cancer NCI-H460 cells.

    PubMed

    Song, Junho; Ko, Hyun-suk; Sohn, Eun Jung; Kim, Bonglee; Kim, Jung Hyo; Kim, Hee Jeong; Kim, Chulwoo; Kim, Jai-eun; Kim, Sung-Hoon

    2014-02-15

    Though glycyrrhetinic acid (GA) from Glycyrrhiza glabra was known to exert antioxidant, antifilarial, hepatoprotective, anti-inflammatory and anti-tumor effects, the antitumor mechanism of GA was not clearly elucidated in non-small cell lung cancer cells (NSCLCCs). Thus, in the present study, the underlying apoptotic mechanism of GA was examined in NCI-H460 NSCLCCs. GA significantly suppressed the viability of NCI-H460 and A549 non-small lung cancer cells. Also, GA significantly increased the sub G1 population by cell cycle analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells in a concentration dependent manner in NCI-H460 non-small lung cancer cells. Consistently, GA cleaved poly (ADP-ribosyl) polymerase (PARP), caspase 9/3, attenuated the expression of Bcl-XL, Bcl-2, Cyclin D1 and Cyclin E in NCI-H460 cells. Interestingly, GA attenuated the phosphorylation of protein kinase C (PKC) α/βII and extracellular activated protein kinase (ERK) as well as activated the phosphorylation of PKC δ and c-Jun NH2-terminal kinase in NCI-H460 cells. Conversely, PKC promoter phorbol 12-myristate 13-acetate (PMA) and JNK inhibitor SP600125 reversed the cleavages of caspase 3 and PARP induced by GA in NCI-H460 cells. Overall, our findings suggest that GA induces apoptosis via inhibition of PKC α/βII and activation of JNK in NCI-H460 non-small lung cancer cells as a potent anticancer candidate for lung cancer treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Zinc protoporphyrin inhibition of lipopolysaccharide-, lipoteichoic acid-, and peptidoglycan-induced nitric oxide production through stimulating iNOS protein ubiquitination.

    PubMed

    Chow, Jyh-Ming; Lin, Hui-Yi; Shen, Shing-Chuan; Wu, Ming-Shun; Lin, Cheng-Wei; Chiu, Wen-Ta; Lin, Chien-Huang; Chen, Yen-Chou

    2009-06-15

    In the present study, zinc protoporphyrin (ZnPP), but not ferric protoporphyrin (FePP), tin protoporphyrin (SnPP), or zinc chloride (ZnCl(2)), at the doses of 0.5, 1, and 2 microM, dose-dependently inhibited lipopolysaccharide- (LPS), lipoteichoic acid (LTA), and peptidoglycan (PGN)-induced inducible nitric oxide (iNOS) and nitric oxide (NO) production with an increase in heme oxygenase 1 (HO-1) protein in RAW264.7 macrophages in a serum-free condition. NO inhibition and HO-1 induction by ZnPP were blocked by the separate addition of fetal bovine serum (FBS) and bovine serum albumin (BSA). A decrease in the iNOS/NO ratio and an increase in HO-1 protein by ZnPP were identified in three different conditions including ZnPP pretreatment, ZnPP co-treatment, and ZnPP post-treatment with LPS and LTA. Activation of c-Jun N-terminal kinases (JNKs) and extracellular regulated kinases (ERKs) were detected in LPS-, LTA-, and PGN-treated RAW264.7 cells, and iNOS/NO production was blocked by adding the JNK inhibitor, SP600125, but not the ERK inhibitor, PD98059. However, ZnPP addition potentiated ERK and JNK protein phosphorylation stimulated by LPS, LTA, and PGN. Increases in total protein ubiquitination and ubiquitinated iNOS proteins were detected in ZnPP-treated macrophages elicited by LPS according to Western and immunoprecipitation/Western blotting assays, respectively. The decrease in LPS-induced iNOS protein by ZnPP was reversed by adding the proteasome inhibitors MG132 and lactacystin. The reduction in HO-1 protein induced by ZnPP via transfection of HO-1 small interfering RNA did not affect the inhibitory effect of ZnPP against LPS-induced iNOS/NO production and protein ubiquitination induced by ZnPP in macrophages. Data of the present study provide the first evidence to support ZnPP effectively inhibiting inflammatory iNOS/NO production through activation of protein ubiquitination in a HO-1-independent manner in macrophages.

  20. Zinc protoporphyrin inhibition of lipopolysaccharide-, lipoteichoic acid-, and peptidoglycan-induced nitric oxide production through stimulating iNOS protein ubiquitination

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chow, J.-M.; Lin, H.-Y.; Shen, S.-C.

    2009-06-15

    In the present study, zinc protoporphyrin (ZnPP), but not ferric protoporphyrin (FePP), tin protoporphyrin (SnPP), or zinc chloride (ZnCl{sub 2}), at the doses of 0.5, 1, and 2 {mu}M, dose-dependently inhibited lipopolysaccharide- (LPS), lipoteichoic acid (LTA), and peptidoglycan (PGN)-induced inducible nitric oxide (iNOS) and nitric oxide (NO) production with an increase in heme oxygenase 1 (HO-1) protein in RAW264.7 macrophages in a serum-free condition. NO inhibition and HO-1 induction by ZnPP were blocked by the separate addition of fetal bovine serum (FBS) and bovine serum albumin (BSA). A decrease in the iNOS/NO ratio and an increase in HO-1 protein bymore » ZnPP were identified in three different conditions including ZnPP pretreatment, ZnPP co-treatment, and ZnPP post-treatment with LPS and LTA. Activation of c-Jun N-terminal kinases (JNKs) and extracellular regulated kinases (ERKs) were detected in LPS-, LTA-, and PGN-treated RAW264.7 cells, and iNOS/NO production was blocked by adding the JNK inhibitor, SP600125, but not the ERK inhibitor, PD98059. However, ZnPP addition potentiated ERK and JNK protein phosphorylation stimulated by LPS, LTA, and PGN. Increases in total protein ubiquitination and ubiquitinated iNOS proteins were detected in ZnPP-treated macrophages elicited by LPS according to Western and immunoprecipitation/Western blotting assays, respectively. The decrease in LPS-induced iNOS protein by ZnPP was reversed by adding the proteasome inhibitors MG132 and lactacystin. The reduction in HO-1 protein induced by ZnPP via transfection of HO-1 small interfering RNA did not affect the inhibitory effect of ZnPP against LPS-induced iNOS/NO production and protein ubiquitination induced by ZnPP in macrophages. Data of the present study provide the first evidence to support ZnPP effectively inhibiting inflammatory iNOS/NO production through activation of protein ubiquitination in a HO-1-independent manner in macrophages.« less

  1. Angiotensin II increases CTGF expression via MAPKs/TGF-{beta}1/TRAF6 pathway in atrial fibroblasts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gu, Jun; Liu, Xu, E-mail: xkliuxu@yahoo.cn; Wang, Quan-xing, E-mail: shmywqx@126.com

    2012-10-01

    The activation of transforming growth factor-{beta}1(TGF-{beta}1)/Smad signaling pathway and increased expression of connective tissue growth factor (CTGF) induced by angiotensin II (AngII) have been proposed as a mechanism for atrial fibrosis. However, whether TGF{beta}1/non-Smad signaling pathways involved in AngII-induced fibrogenetic factor expression remained unknown. Recently tumor necrosis factor receptor associated factor 6 (TRAF6)/TGF{beta}-associated kinase 1 (TAK1) has been shown to be crucial for the activation of TGF-{beta}1/non-Smad signaling pathways. In the present study, we explored the role of TGF-{beta}1/TRAF6 pathway in AngII-induced CTGF expression in cultured adult atrial fibroblasts. AngII (1 {mu}M) provoked the activation of P38 mitogen activated proteinmore » kinase (P38 MAPK), extracellular signal-regulated kinase 1/2(ERK1/2) and c-Jun NH(2)-terminal kinase (JNK). AngII (1 {mu}M) also promoted TGF{beta}1, TRAF6, CTGF expression and TAK1 phosphorylation, which were suppressed by angiotensin type I receptor antagonist (Losartan) as well as p38 MAPK inhibitor (SB202190), ERK1/2 inhibitor (PD98059) and JNK inhibitor (SP600125). Meanwhile, both TGF{beta}1 antibody and TRAF6 siRNA decreased the stimulatory effect of AngII on TRAF6, CTGF expression and TAK1 phosphorylation, which also attenuated AngII-induced atrial fibroblasts proliferation. In summary, the MAPKs/TGF{beta}1/TRAF6 pathway is an important signaling pathway in AngII-induced CTGF expression, and inhibition of TRAF6 may therefore represent a new target for reversing Ang II-induced atrial fibrosis. -- Highlights: Black-Right-Pointing-Pointer MAPKs/TGF{beta}1/TRAF6 participates in AngII-induced CTGF expression in atrial fibroblasts. Black-Right-Pointing-Pointer TGF{beta}1/TRAF6 participates in AngII-induced atrial fibroblasts proliferation. Black-Right-Pointing-Pointer TRAF6 may represent a new target for reversing Ang II-induced atrial fibrosis.« less

  2. Ceramidastin, a novel bacterial ceramidase inhibitor, produced by Penicillium sp. Mer-f17067.

    PubMed

    Inoue, Hiroyuki; Someno, Tetsuya; Kato, Taira; Kumagai, Hiroyuki; Kawada, Manabu; Ikeda, Daishiro

    2009-02-01

    Decrease of ceramide in the skin is one of the aggravating factors of atopic dermatitis. The skin is often infected by ceramidase-producing bacteria, such as Pseudomonas aeruginosa. The bacterial ceramidase then degrades ceramide in the skin. To develop anti-atopic dermatitis drugs, we searched for ceramidase inhibitors, which led to the discovery of ceramidastin, a novel inhibitor of bacterial ceramidase, from the culture broth of Penicillium sp. Mer-f17067. Ceramidastin inhibited the bacterial ceramidase with an IC(50) value of 6.25 microg ml(-1). Here we describe the isolation, physicochemical properties, structure determination and biological activity of ceramidastin.

  3. Both internalization and AIP1 association are required for tumor necrosis factor receptor 2-mediated JNK signaling.

    PubMed

    Ji, Weidong; Li, Yonghao; Wan, Ting; Wang, Jing; Zhang, Haifeng; Chen, Hong; Min, Wang

    2012-09-01

    The proinflammtory cytokine tumor necrosis factor (TNF), primarily via TNF receptor 1 (TNFR1), induces nuclear factor-κB (NF-κB)-dependent cell survival, and c-Jun N-terminal kinase (JNK) and caspase-dependent cell death, regulating vascular endothelial cell (EC) activation and apoptosis. However, signaling by the second receptor, TNFR2, is poorly understood. The goal of this study was to dissect how TNFR2 mediates NF-κB and JNK signaling in vascular EC, and its relevance to in vivo EC function. We show that TNFR2 contributes to TNF-induced NF-κB and JNK signaling in EC as TNFR2 deletion or knockdown reduces the TNF responses. To dissect the critical domains of TNFR2 that mediate the TNF responses, we examine the activity of TNFR2 mutant with a specific deletion of the TNFR2 intracellular region, which contains conserved domain I, domain II, domain III, and 2 TNFR-associated factor-2-binding sites. Deletion analyses indicate that different sequences on TNFR2 have distinct roles in NF-κB and JNK activation. Specifically, deletion of the TNFR-associated factor-2-binding sites (TNFR2-59) diminishes the TNFR2-mediated NF-κB, but not JNK activation; whereas, deletion of domain II or domain III blunts TNFR2-mediated JNK but not NF-κB activation. Interestingly, we find that the TNFR-associated factor-2-binding sites ensure TNFR2 on the plasma membrane, but the di-leucine LL motif within the domain II and aa338-355 within the domain III are required for TNFR2 internalization as well as TNFR2-dependent JNK signaling. Moreover, domain III of TNFR2 is responsible for association with ASK1-interacting protein-1, a signaling adaptor critical for TNF-induced JNK signaling. While TNFR2 containing the TNFR-associated factor-2-binding sites prevents EC cell death, a specific activation of JNK without NF-κB activation by TNFR2-59 strongly induces caspase activation and EC apoptosis. Our data reveal that both internalization and ASK1-interacting protein-1 association are

  4. Eicosapentaenoic acid (EPA) induced apoptosis in HepG2 cells through ROS–Ca{sup 2+}–JNK mitochondrial pathways

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Yuanyuan; Han, Lirong; Qi, Wentao

    Highlights: • EPA evoked ROS formation, [Ca{sup 2+}]{sub c} accumulation, the opening of MPTP and the phosphorylation of JNK. • EPA-induced [Ca{sup 2+}]{sub c} elevation was depended on production of ROS. • EPA-induced ROS generation, [Ca{sup 2+}]{sub c} increase, and JNK activated caused MPTP opening. • The apoptosis induced by EPA was related to release of cytochrome C through the MPTP. • EPA induced HepG2 cells apoptosis through ROS–Ca{sup 2+}–JNK mitochondrial pathways. - Abstract: Eicosapentaenoic acid (EPA), a well-known dietary n−3 PUFAS, has been considered to inhibit proliferation of tumor cells. However, the molecular mechanism related to EPA-induced liver cancermore » cells apoptosis has not been reported. In this study, we investigated the effect of EPA on HepG2 cells proliferation and apoptosis mechanism through mitochondrial pathways. EPA inhibited proliferation of HepG2 cells in a dose-dependent manner and had no significant effect on the cell viability of humor normal liver L-02 cells. It was found that EPA initially evoked ROS formation, leading to [Ca{sup 2+}]{sub c} accumulation and the mitochondrial permeability transition pore (MPTP) opening; EPA-induced HepG2 cells apoptosis was inhibited by N-acetylcysteine (NAC, an inhibitor of ROS), 1,2-bis (2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM, a chelator of calcium) and CsA (inhibitor of MPTP). The relationship between ROS production, the increase of cytoplasmic Ca and MPTP opening was detected. It seems that ROS may act as an upstream regulator of EPA-induced [Ca{sup 2+}]{sub c} generation, moreover, generation of ROS, overload of mitochondrial [Ca{sup 2+}]{sub c}, and JNK activated cause the opening of MPTP. Western blotting results showed that EPA elevated the phosphorylation status of JNK, processes associated with the ROS generation. Simultaneously, the apoptosis induced by EPA was related to release of cytochrome C from mitochondria to cytoplasm through

  5. Activation of neurokinin-1 receptors up-regulates substance P and neurokinin-1 receptor expression in murine pancreatic acinar cells

    PubMed Central

    Koh, Yung-Hua; Moochhala, Shabbir; Bhatia, Madhav

    2012-01-01

    Abstract Acute pancreatitis (AP) has been associated with an up-regulation of substance P (SP) and neurokinin-1 receptor (NK1R) in the pancreas. Increased SP-NK1R interaction was suggested to be pro-inflammatory during AP. Previously, we showed that caerulein treatment increased SP/NK1R expression in mouse pancreatic acinar cells, but the effect of SP treatment was not evaluated. Pancreatic acinar cells were obtained from pancreas of male swiss mice (25–30 g). We measured mRNA expression of preprotachykinin-A (PPTA) and NK1R following treatment of SP (10−6M). SP treatment increased PPTA and NK1R expression in isolated pancreatic acinar cells, which was abolished by pretreatment of a selective NK1R antagonist, CP96,345. SP also time dependently increased protein expression of NK1R. Treatment of cells with a specific NK1R agonist, GR73,632, up-regulated SP protein levels in the cells. Using previously established concentrations, pre-treatment of pancreatic acinar cells with Gö6976 (10 nM), rottlerin (5 μM), PD98059 (30 μM), SP600125 (30 μM) or Bay11-7082 (30 μM) significantly inhibited up-regulation of SP and NK1R. These observations suggested that the PKC-ERK/JNK-NF-κB pathway is necessary for the modulation of expression levels. In comparison, pre-treatment of CP96,345 reversed gene expression in SP-induced cells, but not in caerulein-treated cells. Overall, the findings in this study suggested a possible auto-regulatory mechanism of SP/NK1R expression in mouse pancreatic acinar cells, via activation of NK1R. Elevated SP levels during AP might increase the occurrence of a positive feedback loop that contributes to abnormally high expression of SP and NK1R. PMID:22040127

  6. Phloretin induces apoptosis of non-small cell lung carcinoma A549 cells via JNK1/2 and p38 MAPK pathways.

    PubMed

    Min, Jie; Huang, Kenan; Tang, Hua; Ding, Xinyu; Qi, Chen; Qin, Xiong; Xu, Zhifei

    2015-12-01

    Phloretin (Ph) existing in apples, pears and various vegetables is known to have antitumor activities in several cancer cell lines. However, little is known about its effect on human lung cancer cells. The aim of the present study was to see whether Ph could induce apoptosis of non-small cell lung cancer (NSCLC) cells, and explore the possible underlying mechanism of action. We found that Ph markedly induced cell apoptosis of NSCLC cell line A549, and inhibited the migration of A549 cells in a dose-dependent manner. The expression level of BAX, cleaved caspase-3 and -9, and degraded form of PARP was increased and Bcl-2 was decreased after Ph treatment. In addition, the phosphorylation of P38 MAPK, ERK1/2 and JNK1/2 was increased in a dose‑dependent manner in parallel with Ph treatment. Inhibition of P38 MAPK and JNK1/2 by specific inhibitors significantly abolished the Ph-induced activation of the caspase-3 and -9. In vivo tumor-suppression assay further indicated that Ph (20 mg/kg) displayed a more significant inhibitory effect on A549 xenografts in tumor growth. All these findings indicate that Ph is able to inhibit NSCLC A549 cell growth by inducing apoptosis through P38 MAPK and JNK1/2 pathways, and therefore may prove to be an adjuvant to the treatment of NSCLC.

  7. JNK1 and JNK3 play a significant role in both neuronal apoptosis and necrosis. Evaluation based on in vitro approach using tert-butylhydroperoxide induced oxidative stress in neuro-2A cells and perturbation through 3-aminobenzamide.

    PubMed

    Muthaiah, Vijaya Prakash Krishnan; Michael, Felicia Mary; Palaniappan, Tamilselvi; Rajan, Sridhar Skylab; Chandrasekar, Kirubhanand; Venkatachalam, Sankar

    2017-06-01

    In spinal cord injury (SCI), oxidative stress in the penumbra of the injury site is a characteristic feature. The predominance of necrosis over apoptosis in the ensuing delayed cell death results in progressive waves of necrosis affecting neighboring cells and thus exaggerates the severity of the lesion. Necrosis has been classified into subtypes based on the active molecular players and parthanatos is one among them, which is characterized by the over activation of PARP1 as the pre-mitochondrial event that triggers necrosis. Parthanatos being the necrosis mode reported in SCI, we intended to study the molecular players in the elusive pre-mitochondrial events of PARP1 over activation using an in vitro model. tert-Butylhydroperoxide (tBuOOH) was reported to induce oxidative stress in various cell types including Neuro-2A cells. Using a tailored protocol, a predominantly PARP1 mediated necrotic mode of cell death was obtained in Neuro-2A cells using tBuOOH. By perturbing the progress of necrosis using 3-amniobenzamide, a known PARP1 inhibitor, it was found that JNK1 and JNK3 but not JNK2 were involved in pre-mitochondrial stages of PARP1 mediated cell death. Given that JNK1 and JNK3 play a role in apoptosis also, they may serve as common targets to counter both apoptosis and necrosis. The in vitro model used in the present study may be useful in delineating molecular mechanisms in necrosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Procyanidins from wild grape (Vitis amurensis) seeds regulate ARE-mediated enzyme expression via Nrf2 coupled with p38 and PI3K/Akt pathway in HepG2 cells.

    PubMed

    Bak, Min-Ji; Jun, Mira; Jeong, Woo-Sik

    2012-01-01

    Procyanidins, polymers of flavan-3-ol units, have been reported to exhibit many beneficial health effects such as antioxidant and anti-carcinogenic effects. In this study, we investigated the cancer chemopreventive properties of procyanidins from wild grape (Vitis amurensis) seeds in particular their roles in inducing phase II detoxifying/antioxidant enzymes as well as in modulating the upstream kinases. Ethanolic extract of V. amurensis seeds was fractionated with a series of organic solvents and finally separated into six fractions, F1-F6. Chemical properties of the procyanidins were analyzed by vanillin assay, BuOH-HCl test, and depolymerization with phloroglucinol followed by LC/MS analysis. The F5 had the highest procyanidin content among all the fractions and strongly induced the reporter activity of antioxidant response element as well as the protein expression of nuclear factor E2-related factor (Nrf2) in HepG2 human hepatocarcinoma cells. The procyanidin-rich F5 also strongly induced the expression of the phase II detoxifying and antioxidant enzymes such as NAD(P)H:quinone oxidoreductase1 and hemeoxygenase1. Phosphorylations of the upstream kinases such as MAPKs and PI3K/Akt were significantly increased by treatment with procyanidin fraction. In addition, the procyanidin-mediated Nrf2 expression was partly attenuated by PI3K inhibitor LY294002, and almost completely by p38 inhibitor SB202190, but neither by JNK inhibitor SP600125 nor by MEK1/2 inhibitor U0126. Taken together, the procyanidins from wild grape seeds could be used as a potential natural chemopreventive agent through Nrf2/ARE-mediated phase II detoxifying/antioxidant enzymes induction via p38 and PI3K/Akt pathway.

  9. Long Non-Coding RNA CASC2 Improves Diabetic Nephropathy by Inhibiting JNK Pathway.

    PubMed

    Yang, Huihui; Kan, Quan E; Su, Yong; Man, Hua

    2018-06-11

    It's known that long non-coding RNA CASC2 overexpression inhibit the JNK pathway in some disease models, while JNK pathway activation exacerbates diabetic nephropathy. Therefore we speculate that long non-coding RNA CASC2 can improve diabetic nephropathy by inhibiting JNK pathway. Thus, our study was carried out to investigate the involvement of CASC2 in diabetic nephropathy. We found that serum level of CASC2 was significantly lower in diabetic nephropathy patients than in normal people, and serum level of CASC2 showed no significant correlations with age, gender, alcohol consumption and smoking habits, but was correlated with course of disease. ROC curve analysis showed that serum level of CASC2 could be used to accurately predict diabetic nephropathy. Diabetes mellitus has many complications. This study also included a series of complications of diabetes, such as diabetic retinopathy, diabetic ketoacidosis, diabetic foot infections and diabetic cardiopathy, while serum level of CASC2 was specifically reduced in diabetic nephropathy. CASC2 expression level decreased, while JNK1 phosphorylation level increased in mouse podocyte cells treated with high glucose. CASC2 overexpression inhibited apoptosis of podocyte cells and reduced phosphorylation level of JNK1. We conclude that long non-coding RNA CASC2 may improve diabetic nephropathy by inhibiting JNK pathway. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Determinants of activity of the HIV-1 maturation inhibitor PA-457.

    PubMed

    Li, Feng; Zoumplis, Dorian; Matallana, Claudia; Kilgore, Nicole R; Reddick, Mary; Yunus, Abdul S; Adamson, Catherine S; Salzwedel, Karl; Martin, David E; Allaway, Graham P; Freed, Eric O; Wild, Carl T

    3-O-(3',3'-dimethylsuccinyl) betulinic acid, also termed PA-457 or DSB, is a novel HIV-1 inhibitor that blocks virus maturation by disrupting cleavage of the capsid precursor, CA-SP1. To better define the molecular target for PA-457, we prepared a panel of mutant viruses with point deletions spanning the CA-SP1 cleavage domain and characterized each of these viruses for PA-457 sensitivity. Our results indicate that amino acid residues in the N-terminal half of SP1 serve as determinants of PA-457 activity, while residues in the C-terminal half of SP1 were not involved in compound activity. These findings support and extend previous observations that PA-457 is a specific inhibitor of CA-SP1 cleavage and identify the CA-SP1 domain as the primary viral determinant for this novel inhibitor of HIV-1 replication.

  11. Pterocarpus santalinus L. Regulated Ultraviolet B Irradiation-induced Procollagen Reduction and Matrix Metalloproteinases Expression Through Activation of TGF-β/Smad and Inhibition of the MAPK/AP-1 Pathway in Normal Human Dermal Fibroblasts.

    PubMed

    Gao, Wei; Lin, Pei; Hwang, Eunson; Wang, Yushuai; Yan, Zhengfei; Ngo, Hien T T; Yi, Tae-Hoo

    2018-01-01

    Ultraviolet light-induced reactive oxygen species (ROS) damage human skin and prematurely cause aging. A growing body of research is focusing on considering plants and plant-derived compounds as antiphotoaging therapeutic material. Pterocarpus santalinus L., as an Indian traditional medicine, possesses antidiabetic, anti-inflammatory and antioxidative effects. Here, we studied the antiphotoaging effects of ethanolic extract of P. santalinus L. heartwood (EPS) on ultraviolet radiation B (UVB)-irradiated normal human dermal fibroblasts (NHDFs). Results showed that EPS significantly inhibited the upregulation of matrix metalloproteinases and IL-6 caused by UVB irradiation, and suppressed UVB-induced phosphorylation of extracellular signal-regulated kinase, Jun N-terminal kinase and p38, as well as the activation of AP-1 transcription factors. Further study indicated that UVB-induced production of MMP-1 and IL-6 could be inhibited by PD 98059 (an ERK inhibitor) and SP600125 (A JNK inhibitor), implied that EPS inhibited UVB-induced MMP-1 and IL-6 secretion by inactivating MAPK signaling pathway. In addition, EPS possessed an excellent antioxidant activity, which could increase cytoprotective antioxidants such as HO-1, NQ-O1 expression by facilitating the nuclear accumulation of Nrf2. Treatment of NHDFs with EPS also recovered UVB-induced procollagen type I reduction by activating TGF-β/Smad pathway. These findings demonstrated that EPS had a potential effect against UVB-induced skin photoaging. © 2017 The American Society of Photobiology.

  12. Myricetin treatment induces apoptosis in canine osteosarcoma cells by inducing DNA fragmentation, disrupting redox homeostasis, and mediating loss of mitochondrial membrane potential.

    PubMed

    Park, Hahyun; Park, Sunwoo; Bazer, Fuller W; Lim, Whasun; Song, Gwonhwa

    2018-04-16

    Canine osteosarcoma is an aggressive primary bone tumor that shows metastasis to distal regions and is associated with a high mortality rate. However, the pathophysiological mechanisms of canine osteosarcoma are not well characterized. In addition, development of prognostic factors and novel therapeutic agents is necessary to efficiently treat osteosarcoma. Therefore, we studied the effects of myricetin, an antioxidant found in berries, nuts, teas, wine, and vegetables, on apoptosis and signal transduction in the canine osteosarcoma cell lines, D-17 and DSN. Results of the present study demonstrated that treatment with myricetin decreased cell proliferation and DNA replication, while it increased apoptotic DNA fragmentation in D-17 and DSN cells. In addition, it increased generation of ROS, lipid peroxidation, and depolarization of MMP in both D-17 and DSN cells. Myricetin treatment activated phosphorylation of AKT, p70S6K, ERK1/2, JNK, and p90RSK in canine osteosarcoma cells. Moreover, inhibition of PI3K and MAPK using LY294002, U0126, or SP600125, in addition to myricetin treatment, effectively suppressed cell proliferation compared to treatment with myricetin or each inhibitor alone. Therefore, we concluded that myricetin may be a potentially effective and less toxic therapeutic agent to prevent and control progression of canine osteosarcoma. © 2018 Wiley Periodicals, Inc.

  13. Linking JNK Activity to the DNA Damage Response

    PubMed Central

    Picco, Vincent

    2013-01-01

    The activity of c-Jun N-terminal kinase (JNK) was initially described as ultraviolet- and oncogene-induced kinase activity on c-Jun. Shortly after this initial discovery, JNK activation was reported for a wider variety of DNA-damaging agents, including γ-irradiation and chemotherapeutic compounds. As the DNA damage response mechanisms were progressively uncovered, the mechanisms governing the activation of JNK upon genotoxic stresses became better understood. In particular, a recent set of papers links the physical breakage in DNA, the activation of the transcription factor NF-κB, the secretion of TNF-α, and an autocrine activation of the JNK pathway. In this review, we will focus on the pathway that is initiated by a physical break in the DNA helix, leading to JNK activation and the resultant cellular consequences. The implications of these findings will be discussed in the context of cancer therapy with DNA-damaging agents. PMID:24349633

  14. Cav-1 promotes atherosclerosis by activating JNK-associated signaling.

    PubMed

    Wang, Dong-Xia; Pan, Yong-Quan; Liu, Bing; Dai, Li

    2018-05-07

    The objective of the study is to calculate the role and underlying the molecular mechanisms of caveolin-1 (Cav-1) in atherosclerosis (AS). Cav-1 was mainly expressed in the endothelial cells of atherosclerotic lesions in both human patients and apolipoprotein E deficient (ApoE -/- ) mice. Cav-1 deficiency (Cav-1 -/- ) attenuated high-fat diet (HFD)-induced atherosclerotic lesions in ApoE -/- mice, supported by the reduced aortic plaques. Cav-1 -/- reduced the macrophage content and decreased the release of inflammation-related cytokines or chemokine in serum or abdominal aortas, accompanied with the inactivation of inhibitor κB kinase κ (IKKβ)/p65/IκBα signaling pathway. Also, the activity of mitogen-activated protein kinases 7/c-Jun-N-terminal kinase (MKK7/JNK) signaling was decreased by Cav-1 -/- . In addition, oxidative stress induced by HFD in ApoE -/- mice was alleviated by Cav-1 -/- . In response to HFD, Cav-1 -/- markedly reduced triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDLC) and very low-density lipoprotein-cholesterol (VLDLC) in serum of HFD-fed ApoE -/- mice, whereas enhanced high-density lipoprotein-cholesterol (HDLC) contents. Consistent with these findings, haematoxylin and eosin (H&E) and Oil Red O staining showed fewer lipid droplets in the liver of Cav-1-deficient mice. Further, real time-quantitative PCR (RT-qPCR) analysis indicated that Cav-1 -/- alleviated dyslipidemia both in liver and abdominal aortas of ApoE -/- mice fed with HFD. Cav-1 inhibition-induced attenuation of inflammatory response, oxidative stress and dyslipidemia were confirmed in vitro using mouse vascular smooth muscle cells (VSMCs) treated with ox-LDL. Surprisingly, the processes regulated by Cav-1-knockdown could be abolished through promoting JNK activation in ox-LDL-treated VSMCs. In conclusion, Cav-1 expression could promote HFD-induced AS in a JNK-dependent manner. Copyright © 2018. Published by Elsevier Inc.

  15. Involvement of p38 MAPK activation mediated through AT1 receptors on spinal astrocytes and neurons in angiotensin II- and III-induced nociceptive behavior in mice.

    PubMed

    Nemoto, Wataru; Ogata, Yoshiki; Nakagawasai, Osamu; Yaoita, Fukie; Tadano, Takeshi; Tan-No, Koichi

    2015-12-01

    We have previously demonstrated the possibility that angiotensin (Ang) II and its N-terminal metabolite Ang (1-7) act as neurotransmitters and/or neuromodulators in the spinal transmission of nociceptive information. Ang III, which is a C-terminal metabolite of Ang II, can also act on AT1 receptors, but its role in spinal nociceptive transmission remains unclear. Therefore, we examined the role of Ang III on the spinal nociceptive system in comparison with that of Ang II. Intrathecal (i.t.) administration of Ang III into mice produced a nociceptive behavior, which was dose-dependently inhibited by the co-administration of the AT1 receptor antagonist losartan and the p38 MAPK inhibitor SB203580, but not by the AT2 receptor antagonist PD123319, MEK1/2 inhibitor U0126 and JNK inhibitor SP600125. In addition, Ang III increased the phosphorylation of p38 MAPK in the dorsal lumbar spinal cord, which was inhibited by losartan. These effects were similar to those of observed with Ang II. The nociceptive behavior produced by Ang II or III was also attenuated by the administration of the astrocytic inhibitor L-α-aminoadipic acid, but not by the microglial inhibitor minocycline. Double immunohistochemical staining showed that spinal AT1 receptors were expressed on neurons and astrocytes, and that i.t. administration of either Ang II or III phosphorylated p38 MAPK in both spinal astrocytes and neurons. These results indicate that Ang III produces nociceptive behavior similar to Ang II, and suggest that the phosphorylation of p38 MAPK mediated through AT1 receptors on spinal astrocytes and neurons contributes to Ang II- and III-induced nociceptive behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. JNK1/2-dependent phosphorylation of angulin-1/LSR is required for the exclusive localization of angulin-1/LSR and tricellulin at tricellular contacts in EpH4 epithelial sheet.

    PubMed

    Nakatsu, Daiki; Kano, Fumi; Taguchi, Yuki; Sugawara, Taichi; Nishizono, Takashi; Nishikawa, Kiyotaka; Oda, Yukako; Furuse, Mikio; Murata, Masayuki

    2014-07-01

    Tricellular tight junctions (tTJs) are specialized structural variants of tight junctions within tricellular contacts of an epithelial sheet and comprise several transmembrane proteins including lipolysis-stimulated lipoprotein receptor (angulin-1/LSR) and tricellulin. To elucidate the mechanism of its formation, we carried out stepwise screening of kinase inhibitors followed by RNAi screening to identify kinases that regulate intracellular localization of angulin-1/LSR to the tTJs using a fluorescence image-based screen. We found that the activity of JNK1 and JNK2, but not JNK3, was required for the exclusive localization of angulin-1/LSR at the tTJs. Based on a bioinformatics approach, we estimated the potential phosphorylation site of angulin-1/LSR by JNK1 to be serine 288 and experimentally confirmed that JNK1 directly phosphorylates angulin-1/LSR at this site. We found that JNK2 was also involved in the phosphorylation of angulin-1/LSR. Furthermore, GFP-tagged angulin-1/LSR(S288A), in which serine 288 was substituted by alanine, was observed to be dispersed to bicellular junctions, indicating that phosphorylation of Ser288 is crucial for the exclusive localization of angulin-1/LSR and tricellulin at tTJs. Our fluorescence image-based screening for kinases inhibitor or siRNAs combined with the phosphorylation site prediction could become a versatile and useful tool to elucidate the mechanisms underlying the maintenance of tTJs regulated by kinase networks. © 2014 The Authors Genes to Cells © 2014 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  17. Drosophila MOF regulates DIAP1 and induces apoptosis in a JNK dependent pathway.

    PubMed

    Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Ramaiah, M Janaki; Koteswara Rao, G; Bag, Indira; Bhadra, Utpal; Pal-Bhadra, Manika

    2016-03-01

    Histone modulations have been implicated in various cellular and developmental processes where in Drosophila Mof is involved in acetylation of H4K16. Reduction in the size of larval imaginal discs is observed in the null mutants of mof with increased apoptosis. Deficiency involving Hid, Reaper and Grim [H99] alleviated mof (RNAi) induced apoptosis in the eye discs. mof (RNAi) induced apoptosis leads to activation of caspases which is suppressed by over expression of caspase inhibitors like P35 and Diap1 clearly depicting the role of caspases in programmed cell death. Also apoptosis induced by knockdown of mof is rescued by JNK mutants of bsk and tak1 indicating the role of JNK in mof (RNAi) induced apoptosis. The adult eye ablation phenotype produced by ectopic expression of Hid, Rpr and Grim, was restored by over expression of Mof. Accumulation of Mof at the Diap1 promoter 800 bp upstream of the transcription start site in wild type larvae is significantly higher (up to twofolds) compared to mof (1) mutants. This enrichment coincides with modification of histone H4K16Ac indicating an induction of direct transcriptional up regulation of Diap1 by Mof. Based on these results we propose that apoptosis triggered by mof (RNAi) proceeds through a caspase-dependent and JNK mediated pathway.

  18. Crosstalk between Fas and JNK determines lymphocyte apoptosis after ionizing radiation.

    PubMed

    Praveen, Koganti; Saxena, Nandita

    2013-06-01

    Radiation simultaneously activate Fas and JNK pathway in lymphocytes but their precise interaction is not clearly understood. Activation of Fas pathway is required for radiation induced apoptosis, however induction of JNK pathway may or may not contribute in apoptosis. Here we report that Fas, Fas associated death domain and total JNK are activated in a dose- and time-dependent radiation exposure. A biphasic pattern of phospho-JNK was found at lower doses (1 and 2 Gy), however at higher doses of radiation phospho-JNK was continuously activated. Interestingly, Fas ligand expression remained biphasic at all the doses of radiation. Our results suggest that the Fas pathway is the major player in radiation-induced apoptosis, with JNK playing a contributory role. We also observed that Fas ligand expression by radiation is dependent on JNK activation. We also propose that radiation activates JNK pathway, but sustained activation is required for maximal induction of apoptosis at later times. Our findings define a mechanism for crosstalk between JNK and Fas pathway in radiation-induced apoptosis, which may lead to the development of new therapeutic strategies.

  19. Induction of apoptosis in PA-1 ovarian cancer cells by vitamin K2 is associated with an increase in the level of TR3/Nur77 and its accumulation in mitochondria and nuclei.

    PubMed

    Sibayama-Imazu, Toshiko; Fujisawa, Yukari; Masuda, Yutaka; Aiuchi, Toshihiro; Nakajo, Shigeo; Itabe, Hiroyuki; Nakaya, Kazuyasu

    2008-07-01

    We examined the growth-inhibitory and apoptosis-inducing effects of vitamin K(2) (VK(2); menaquinone-4) on various lines of human ovarian cancer cells to study the mechanism of induction of apoptosis by VK(2). Cell proliferation was determined by XTT method, and apoptotic cells were detected by Hoechst staining. TR3, also known as Nur77 and NGFI-B, was detected by immunoblotting and immunofluorescence analysis. Role of TR3 on induction of apoptosis was examined by a siRNA experiment. We found that PA-1 cells were the most sensitive to VK(2) (IC(50) = 5.0 +/- 0.7 microM), while SK-OV-3 cells were resistant to VK(2). Immunoblotting and immunofluorescence analyses indicated that levels of TR3 were elevated in cell lysates 48 h after the start of treatment with 30 microM VK(2). In the VK(2)-treated cells, TR3 accumulated at significant levels in mitochondria, as well as in the nuclei of PA-1 cells. No similar changes were observed in SK-OV-3 cells under the same conditions. Treatment of PA-1 cells with small interfering RNA (siRNA) directed against TR3, and with cycloheximide or SP600125 (an inhibitor of c-jun N-terminal kinase; JNK), separately, inhibited the VK(2)-induced synthesis of TR3 and apoptosis. From these results, we can conclude that an increase in the synthesis of TR3 and the accumulation of TR3 in mitochondria and in nuclei might be involved in the induction of apoptosis by VK(2) and that the synthesis of TR3 might be regulated through a JNK signaling pathway.

  20. Dragmacidins: new protein phosphatase inhibitors from a southern australian deep-water marine sponge, spongosorites sp

    PubMed

    Capon; Rooney; Murray; Collins; Sim; Rostas; Butler; Carroll

    1998-05-01

    A Spongosorites sp. collected during trawling operations off the southern coast of Australia returned the new alkaloid dragmacidin E (3), the structure of which was secured by detailed spectroscopic analysis. Dragmacidin E (3), and its co-metabolite dragmacidin D (1) have been identified as potent inhibitors of serine-threonine protein phosphatases.

  1. Inhibitors of stress-activated protein/mitogen-activated protein kinase pathways.

    PubMed

    Malemud, Charles J

    2007-06-01

    The importance of stress-activated protein/mitogen-activated protein kinase (SAP/MAPK) pathway signalling (involving c-Jun-N-terminal kinase [JNK], extracellular signal-regulated kinase [ERK] and p38 kinase) in normal cellular proliferation, differentiation and programmed cell death has led to significant recent advances in our understanding of the role of SAP/MAPK signaling in inflammatory disorders such as arthritis and cardiovascular disease, cancer, and pulmonary and neurogenerative diseases. The discovery that several natural products such as resveratrol, tangeretin and ligustilide non-specifically inhibit SAP/MAPK signalling in vitro should now be logically extended to studies designed to determine how agents in these natural products regulate SAP/MAPK pathways in animal models of disease. A new generation of small-molecule SAP/MAPK inhibitors that demonstrate increasing specificity for each of the JNK, ERK and p38 kinase isoforms has shown promise in animal studies and could eventually prove effective for treating human diseases. Several of these compounds are already being tested in human subjects to assess their oral bioavailability, pharmacokinetics and toxicity.

  2. Glabridin induces apoptosis and cell cycle arrest in oral cancer cells through the JNK1/2 signaling pathway.

    PubMed

    Chen, Chang-Tai; Chen, Yi-Tzu; Hsieh, Yi-Hsien; Weng, Chia-Jui; Yeh, Jung-Chun; Yang, Shun-Fa; Lin, Chiao-Wen; Yang, Jia-Sin

    2018-06-01

    Glabridin, a flavonoid extracted from licorice (Glycyrrhiza glabra), possesses various biological properties, including anticancer activities. However, the effect of glabridin on oral cancer cell apoptosis and the underlying molecular mechanisms has not been elucidated. In this study, we demonstrated that glabridin treatment significantly inhibits cell proliferation in human oral cancer SCC-9 and SAS cell lines. Flow cytometric assays demonstrated that glabridin induced several features of apoptosis, such as sub-G1 phase cell increase and phosphatidylserine externalization. Furthermore, glabridin induced apoptosis dose-dependently in SCC-9 cells through caspase-3, -8, and -9 activation and poly (ADP-ribose) polymerase cleavage. Moreover, glabridin increased the phosphorylation of the extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase (JNK) pathways in a dose-dependent manner. Moreover, the inhibition of the JNK1/2 inhibitor significantly reversed the glabridin-induced activation of the caspase pathway. In conclusion, our findings suggest that glabridin induces oral cancer cell apoptosis through the JNK1/2 pathway and is a potential therapeutic agent for oral cancer. © 2018 Wiley Periodicals, Inc.

  3. Phloretin induces apoptosis of non-small cell lung carcinoma A549 cells via JNK1/2 and p38 MAPK pathways

    PubMed Central

    MIN, JIE; LI, XU; HUANG, KENAN; TANG, HUA; DING, XINYU; QI, CHEN; QIN, XIONG; XU, ZHIFEI

    2015-01-01

    Phloretin (Ph) existing in apples, pears and various vegetables is known to have antitumor activities in several cancer cell lines. However, little is known about its effect on human lung cancer cells. The aim of the present study was to see whether Ph could induce apoptosis of non-small cell lung cancer (NSCLC) cells, and explore the possible underlying mechanism of action. We found that Ph markedly induced cell apoptosis of NSCLC cell line A549, and inhibited the migration of A549 cells in a dose-dependent manner. The expression level of BAX, cleaved caspase-3 and -9, and degraded form of PARP was increased and Bcl-2 was decreased after Ph treatment. In addition, the phosphorylation of P38 MAPK, ERK1/2 and JNK1/2 was increased in a dose-dependent manner in parallel with Ph treatment. Inhibition of P38 MAPK and JNK1/2 by specific inhibitors significantly abolished the Ph-induced activation of the caspase-3 and -9. In vivo tumor-suppression assay further indicated that Ph (20 mg/kg) displayed a more significant inhibitory effect on A549 xenografts in tumor growth. All these findings indicate that Ph is able to inhibit NSCLC A549 cell growth by inducing apoptosis through P38 MAPK and JNK1/2 pathways, and therefore may prove to be an adjuvant to the treatment of NSCLC. PMID:26503828

  4. [The effect of edaravone on MAPKs signal pathway associated with Abeta(25-35) treatment in PC12 cells].

    PubMed

    Zhang, Gui-lian; Guo, Ying-ying; Zhang, Lei; Li, Ting-ting; Du, Yun; Yao, Li; Zhang, Wang-gang; Wu, Hai-qin; Ma, Zhu-lin

    2015-03-01

    To explore whether edaravone protects cells damage via mitogen-activated protein kinases (MAPKs) signal pathway, and which procedure of p38 be affected so as to add theories for AD pathogenesis and treatments. According to different drugs treated, PC12 cells in vitro were divided into four groups. Negative control group: cells were treated with media alone. AD model group: cells were treated with 30 pmol/L Abeta(25-35). Inhibitor control group: cells were treated with 10 micromol/L SB203580 Cp38 mitogen-activated protein kinase (p38) inhibitor], 10 micromol/L SP600125 [c-Jun NH2 terminal kinase (JNK) inhibitor], or 10 micromol/L PD98059 extracelular signal regulated kinase (ERK) inhibitor]. Low-dose, middle-dose and high-dose edaravone group: cells plated for 24 hours treated with 30 micromol/L Abeta(25-35) and co-treated with 20, 40, 80 micromol/L edaravone 3 hours, respectively. The morphology of the treated cells were observed, the p-p38, p-JNK and p-ERK proteins in each group were tested by the Western blot. The p38 mRNA were tested in each group above (only add SB203580 10 micromol/L in third group) by the real time PCR. (1) The p-p38 protein was significantly increased in model control group compared with that in negative control group (P<0.05). The p-p38 protein in the inhibitor group and edaravone groups was decreased significantly (P<0.05) when compared with that in model control group. The p-p38 proteins were significantly increased in the three edaravone groups compared with that in inhibiter control group (P<0.05). The p-p38 protein in middle-dose edaravone group was decreased compared with that in low-dose edaravone group (P<0.05). There was no relationship in dose-dependent manner about edaravone. Compared with three edaravone groups, the p-p38 protein was lower than it in high-dose edaravone & inhibiter group (P<0.05). (2) The p-JNK protein was significantly increased in model control group compared with that in negative control group (P<0.05). The p-JNK

  5. Inhibiting Src family tyrosine kinase activity blocks glutamate signalling to ERK1/2 and Akt/PKB but not JNK in cultured striatal neurones.

    PubMed

    Crossthwaite, Andrew J; Valli, Haseeb; Williams, Robert J

    2004-03-01

    Glutamate receptor activation of mitogen-activated protein (MAP) kinase signalling cascades has been implicated in diverse neuronal functions such as synaptic plasticity, development and excitotoxicity. We have previously shown that Ca2+-influx through NMDA receptors in cultured striatal neurones mediates the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt/protein kinase B (PKB) through a phosphatidylinositol 3-kinase (PI 3-kinase)-dependent pathway. Exposing neurones to the Src family tyrosine kinase inhibitor PP2, but not the inactive analogue PP3, inhibited NMDA receptor-induced phosphorylation of ERK1/2 and Akt/PKB in a concentration-dependent manner, and reduced cAMP response element-binding protein (CREB) phosphorylation. To establish a link between Src family tyrosine kinase-mediated phosphorylation and PI 3-kinase signalling, affinity precipitation experiments were performed with the SH2 domains of the PI 3-kinase regulatory subunit p85. This revealed a Src-dependent phosphorylation of a focal adhesion kinase (FAK)-p85 complex on glutamate stimulation. Demonstrating that PI3-kinase is not ubiquitously involved in NMDA receptor signal transduction, the PI 3-kinase inhibitors wortmannin and LY294002 did not prevent NMDA receptor Ca2+-dependent phosphorylation of c-Jun N-terminal kinase 1/2 (JNK1/2). Further, inhibiting Src family kinases increased NMDA receptor-dependent JNK1/2 phosphorylation, suggesting that Src family kinase-dependent cascades may physiologically limit signalling to JNK. These results demonstrate that Src family tyrosine kinases and PI3-kinase are pivotal regulators of NMDA receptor signalling to ERK/Akt and JNK in striatal neurones.

  6. PLCγ2 promotes apoptosis while inhibits proliferation in rat hepatocytes through PKCD/JNK MAPK and PKCD/p38 MAPK signalling.

    PubMed

    Chen, Xiaoguang; Lv, Qiongxia; Ma, Jun; Liu, Yumei

    2018-02-11

    The PLCG2 (PLCγ2) gene is a member of PLC gene family encoding transmembrane signalling enzymes involved in various biological processes including cell proliferation and apoptosis. Our earlier study indicated that PLCγ2 may be involved in the termination of regeneration of the liver which is mainly composed of hepatocytes, but its exact biological function and molecular mechanism in liver regeneration termination remains unclear. This study aims to examine the role of PLCγ2 in the growth of hepatocytes. A recombinant adenovirus expressing PLCγ2 was used to infect primary rat hepatocytes. PLCγ2 mRNA and protein levels were detected by qRT-PCR and Western blot. The subcellular location of PLCγ2 protein was tested by an immunofluorescence assay. The proliferation of hepatocytes was measured by MTT assay. The cell cycle and apoptosis were analysed by flow cytometry. Caspase-3, -8 and -9 activities were measured by a spectrophotometry method. Phosphorylation levels of PKCD, JNK and p38 in the infected cells were detected by Western blot. The possible mechanism underlying the role of PLCγ2 in hepatocyte growth was also explored by adding a signalling pathway inhibitor. Hepatocyte proliferation was dramatically reduced, while cell apoptosis was remarkably increased. The results demonstrated that PLCγ2 increased the phosphorylation of PKCD, p38 and JNK in rat hepatocytes. After PKCD activity was inhibited by the inhibitor Go 6983, the levels of both p-p38 and p-JNK MAPKs significantly decreased, and PLCγ2-induced cell proliferation inhibition and cell apoptosis were obviously reversed. This study showed that PLCγ2 regulates hepatocyte growth through PKCD-dependently activating p38 MAPK and JNK MAPK pathways; this result was experimentally based on the further exploration of the effect of PLCγ2 on hepatocyte growth in vivo. © 2018 John Wiley & Sons Ltd.

  7. Complete inhibition of anisomycin and UV radiation but not cytokine induced JNK and p38 activation by an aryl-substituted dihydropyrrolopyrazole quinoline and mixed lineage kinase 7 small interfering RNA.

    PubMed

    Wang, Xushan; Mader, Mary M; Toth, John E; Yu, Xiaohong; Jin, Najia; Campbell, Robert M; Smallwood, Jeffrey K; Christe, Michael E; Chatterjee, Arindam; Goodson, Theodore; Vlahos, Chris J; Matter, William F; Bloem, Laura J

    2005-05-13

    Mixed lineage kinase 7 (MLK7) is a mitogen-activated protein kinase kinase kinase (MAPKKK) that activates the pro-apoptotic signaling pathways p38 and JNK. A library of potential kinase inhibitors was screened, and a series of dihydropyrrolopyrazole quinolines was identified as highly potent inhibitors of MLK7 in vitro catalytic activity. Of this series, an aryl-substituted dihydropyrrolopyrazole quinoline (DHP-2) demonstrated an IC50 of 70 nM for inhibition of pJNK formation in COS-7 cell MLK7/JNK co-transfection assays. In stimulated cells, DHP-2 at 200 nM or MLK7 small interfering RNA completely blocked anisomycin and UV induced but had no effect on interleukin-1beta or tumor necrosis factor-alpha-induced p38 and JNK activation. Additionally, the compound blocked anisomycin and UV-induced apoptosis in COS-7 cells. Heart tissue homogenates from MLK7 transgenic mice treated with DHP-2 at 30 mg/kg had reduced JNK and p38 activation with no apparent effect on ERK activation, demonstrating that this compound can be used to block MLK7-driven MAPK pathway activation in vivo. Taken together, these data demonstrate that MLK7 is the MAPKKK required for modulation of the stress-activated MAPKs downstream of anisomycin and UV stimulation and that DHP-2 can be used to block MLK7 pathway activation in cells as well as in vivo.

  8. The novel gluconeogenesis inhibitor FR225654 that originates from Phoma sp. no. 00144. I. Taxonomy, fermentation, isolation and physico-chemical properties.

    PubMed

    Ohtsu, Yoshihiro; Sasamura, Hiromi; Tanaka, Miho; Tsurumi, Yasuhisa; Yoshimura, Seiji; Takase, Shigehiro; Shibata, Toshihiro; Hino, Motohiro; Nakajima, Hidenori

    2005-07-01

    FR225654, a novel gluconeogenesis inhibitor, was isolated from the culture broth of Phoma sp. No. 00144 and purified by adsorptive resin and reverse-phase column chromatography. This compound is a potent inhibitor of gluconeogenesis and is a promising candidate of anti-diabetic agent.

  9. Glutamine deprivation stimulates mTOR-JNK-dependent chemokine secretion

    PubMed Central

    Shanware, Naval P.; Bray, Kevin; Eng, Christina H.; Wang, Fang; Follettie, Maximillian; Myers, Jeremy; Fantin, Valeria R.; Abraham, Robert T.

    2014-01-01

    The non-essential amino acid, glutamine, exerts pleiotropic effects on cell metabolism, signalling and stress resistance. Here we demonstrate that short-term glutamine restriction triggers an endoplasmic reticulum (ER) stress response that leads to production of the pro-inflammatory chemokine, interleukin-8 (IL-8). Glutamine deprivation-induced ER stress triggers colocalization of autophagosomes, lysosomes and the Golgi into a subcellular structure whose integrity is essential for IL-8 secretion. The stimulatory effect of glutamine restriction on IL-8 production is attributable to depletion of tricarboxylic acid cycle intermediates. The protein kinase, mTOR, is also colocalized with the lysosomal membrane clusters induced by glutamine deprivation, and inhibition of mTORC1 activity abolishes both endomembrane reorganization and IL-8 secretion. Activated mTORC1 elicits IL8 gene expression via the activation of an IRE1-JNK signalling cascade. Treatment of cells with a glutaminase inhibitor phenocopies glutamine restriction, suggesting that these results will be relevant to the clinical development of glutamine metabolism inhibitors as anticancer agents. PMID:25254627

  10. Inhibition of JNK by pi class of glutathione S-transferase through PKA/CREB pathway is associated with carnosic acid protection against 6-hydroxydopamine-induced apoptosis.

    PubMed

    Lin, Chia-Yuan; Fu, Ru-Huei; Chou, Ruey-Hwang; Chen, Jing-Hsien; Wu, Chi-Rei; Chang, Shu-Wei; Tsai, Chia-Wen

    2017-05-01

    Pi class of glutathione S-transferase (GST) is known to suppress c-Jun N-terminal kinase (JNK)-related apoptosis through protein-protein interactions. Moreover, signaling by PKA/cAMP response element binding protein (CREB) is necessary for GSTP up-regulation. This study explored whether carnosic acid (CA) from rosemary prevents 6-hydroxydopamine (6-OHDA)-induced neurotoxicity by inhibition of JNK through GSTP via PKA/CREB signaling. Results indicated that the GSTP protein was increased in SH-SY5Y cells treated with CA for 18 and 24 h. However, CA had no significant effect on alpha or mu class of GST. Treatment of CA increased the induction of p-PKAα, nuclear p-CREB, and CRE-DNA binding activity. These effects of CA were attenuated in cells pretreated with the PKA inhibitor H89. CA pretreatment suppressed 6-OHDA-induced apoptosis by inhibition of JNK phosphorylation, poly(ADP)-ribose polymerase cleavage, and nuclear condensation. Pretreatment with H89 and GSTP siRNA attenuated the ability of CA to reverse 6-OHDA-induced apoptosis. By use of immunoprecipitation with JNK antibody to examine the interaction of GSTP-JNK with CA, we showed that CA pretreatment increased the immunoprecipitation of GSTP after 6-OHDA treatment, which suggests that CA promoted the interaction between GSTP and JNK. CA prevents 6-OHDA-induced apoptosis via inhibition of JNK by GSTP through the PKA/CREB pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Cytotoxicity of various types of gold-mesoporous silica nanoparticles in human breast cancer cells

    PubMed Central

    Liu, Guomu; Li, Qiongshu; Ni, Weihua; Zhang, Nannan; Zheng, Xiao; Wang, Yingshuai; Shao, Dan; Tai, Guixiang

    2015-01-01

    Recently, gold nanoparticles (AuNPs) have shown promising biological applications due to their unique electronic and optical properties. However, the potential toxicity of AuNPs remains a major hurdle that impedes their use in clinical settings. Mesoporous silica is very suitable for the use as a coating material for AuNPs and might not only reduce the cytotoxicity of cetyltrimethylammonium bromide-coated AuNPs but might also facilitate the loading and delivery of drugs. Herein, three types of rod-like gold-mesoporous silica nanoparticles (termed bare AuNPs, core–shell Au@mSiO2NPs, and Janus Au@mSiO2NPs) were specially designed, and the effects of these AuNPs on cellular uptake, toxic behavior, and mechanism were then systematically studied. Our results indicate that bare AuNPs exerted higher toxicity than the Au@mSiO2NPs and that Janus Au@mSiO2NPs exhibited the lowest toxicity in human breast cancer MCF-7 cells, consistent with the endocytosis capacity of the nanoparticles, which followed the order, bare AuNPs > core–shell Au@mSiO2NPs > Janus Au@mSiO2NPs. More importantly, the AuNPs-induced apoptosis of MCF-7 cells exhibited features that were characteristic of intracellular reactive oxygen species (ROS) generation, activation of c-Jun-N-terminal kinase (JNK) phosphorylation, an enhanced Bax-to-Bcl-2 ratio, and loss of the mitochondrial membrane potential. Simultaneously, cytochrome c was released from mitochondria, and the caspase-3/9 cascade was activated. Moreover, both ROS scavenger (N-acetylcysteine) and JNK inhibitor (SP600125) partly blocked the induction of apoptosis in all AuNPs-treated cells. Taken together, these findings suggest that all AuNPs induce apoptosis through the ROS-/JNK-mediated mitochondrial pathway. Thus, Janus Au@mSiO2NPs exhibit the potential for applications in biomedicine, thus aiding the clinical translation of AuNPs. PMID:26491285

  12. Eicosapentaenoic acid (EPA) induced apoptosis in HepG2 cells through ROS-Ca(2+)-JNK mitochondrial pathways.

    PubMed

    Zhang, Yuanyuan; Han, Lirong; Qi, Wentao; Cheng, Dai; Ma, Xiaolei; Hou, Lihua; Cao, Xiaohong; Wang, Chunling

    2015-01-24

    Eicosapentaenoic acid (EPA), a well-known dietary n-3 PUFAS, has been considered to inhibit proliferation of tumor cells. However, the molecular mechanism related to EPA-induced liver cancer cells apoptosis has not been reported. In this study, we investigated the effect of EPA on HepG2 cells proliferation and apoptosis mechanism through mitochondrial pathways. EPA inhibited proliferation of HepG2 cells in a dose-dependent manner and had no significant effect on the cell viability of humor normal liver L-02 cells. It was found that EPA initially evoked ROS formation, leading to [Ca(2+)]c accumulation and the mitochondrial permeability transition pore (MPTP) opening; EPA-induced HepG2 cells apoptosis was inhibited by N-acetylcysteine (NAC, an inhibitor of ROS), 1,2-bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM, a chelator of calcium) and CsA (inhibitor of MPTP). The relationship between ROS production, the increase of cytoplasmic Ca and MPTP opening was detected. It seems that ROS may act as an upstream regulator of EPA-induced [Ca(2+)]c generation, moreover, generation of ROS, overload of mitochondrial [Ca(2+)]c, and JNK activated cause the opening of MPTP. Western blotting results showed that EPA elevated the phosphorylation status of JNK, processes associated with the ROS generation. Simultaneously, the apoptosis induced by EPA was related to release of cytochrome C from mitochondria to cytoplasm through the MPTP and activation of caspase-9 and caspase-3. These results suggest that EPA induces apoptosis through ROS-Ca(2+)-JNK mitochondrial pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Discovery of potent and selective rhodanine type IKKβ inhibitors by hit-to-lead strategy.

    PubMed

    Song, Hyeseung; Lee, Yun Suk; Roh, Eun Joo; Seo, Jae Hong; Oh, Kwang-Seok; Lee, Byung Ho; Han, Hogyu; Shin, Kye Jung

    2012-09-01

    Regulation of NF-κB activation through the inhibition of IKKβ has been identified as a promising target for the treatment of inflammatory and autoimmune disease such as rheumatoid arthritis. In order to develop novel IKKβ inhibitors, we performed high throughput screening toward around 8000 library compounds, and identified a hit compound containing rhodanine moiety. We modified the structure of hit compound to obtain potent and selective IKKβ inhibitors. Throughout hit-to-lead studies, we have discovered optimized compounds which possess blocking effect toward NF-κB activation and TNFα production in cell as well as inhibition activity against IKKβ. Among them, compound 3q showed the potent inhibitory activity against IKKβ, and excellent selectivity over other kinases such as p38α, p38β, JNK1, JNK2, and JNK3 as well as IKKα. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. LPS-Induced Low-Grade Inflammation Increases Hypothalamic JNK Expression and Causes Central Insulin Resistance Irrespective of Body Weight Changes.

    PubMed

    Rorato, Rodrigo; Borges, Beatriz de Carvalho; Uchoa, Ernane Torres; Antunes-Rodrigues, José; Elias, Carol Fuzeti; Elias, Lucila Leico Kagohara

    2017-07-04

    Metabolic endotoxemia contributes to low-grade inflammation in obesity, which causes insulin resistance due to the activation of intracellular proinflammatory pathways, such as the c-Jun N-terminal Kinase (JNK) cascade in the hypothalamus and other tissues. However, it remains unclear whether the proinflammatory process precedes insulin resistance or it appears because of the development of obesity. Hypothalamic low-grade inflammation was induced by prolonged lipopolysaccharide (LPS) exposure to investigate if central insulin resistance is induced by an inflammatory stimulus regardless of obesity. Male Wistar rats were treated with single (1 LPS) or repeated injections (6 LPS) of LPS (100 μg/kg, IP) to evaluate the phosphorylation of the insulin receptor substrate-1 (IRS1), Protein kinase B (AKT), and JNK in the hypothalamus. Single LPS increased the expression of pIRS1, pAKT, and pJNK, whereas the repeated LPS treatment failed to recruit pIRS1 and pAKT. The 6 LPS treated rats showed increased total JNK and pJNK. The 6 LPS rats became unresponsive to the hypophagic effect induced by central insulin administration (12 μM/5 μL, ICV). Prolonged exposure to LPS (24 h) impaired the insulin-induced AKT phosphorylation and the translocation of the transcription factor forkhead box protein O1 (FoxO1) from the nucleus to the cytoplasm of the cultured hypothalamic GT1-7 cells. Central administration of the JNK inhibitor (20 μM/5 μL, ICV) restored the ability of insulin to phosphorylate IRS1 and AKT in 6 LPS rats. The present data suggest that an increased JNK activity in the hypothalamus underlies the development of insulin resistance during prolonged exposure to endotoxins. Our study reveals that weight gain is not mandatory for the development of hypothalamic insulin resistance and the blockade of proinflammatory pathways could be useful for restoring the insulin signaling during prolonged low-grade inflammation as seen in obesity.

  15. Inhibition of inhibitor of kappaB kinases stimulates hepatic stellate cell apoptosis and accelerated recovery from rat liver fibrosis.

    PubMed

    Oakley, Fiona; Meso, Muriel; Iredale, John P; Green, Karen; Marek, Carylyn J; Zhou, Xiaoying; May, Michael J; Millward-Sadler, Harry; Wright, Matthew C; Mann, Derek A

    2005-01-01

    Resolution of liver fibrosis is associated with clearance of hepatic myofibroblasts by apoptosis; development of strategies that promote this process in a selective way is therefore important. The aim of this study was to determine whether the inhibitor of kappaB kinase suppressor sulfasalazine stimulates hepatic myofibroblast apoptosis and recovery from fibrosis. Hepatic myofibroblasts were generated by culture activation of rat and human hepatic stellate cells. Fibrosis was established in rat livers by chronic injury with carbon tetrachloride followed by recovery with or without sulfasalazine (150 mg/kg) treatment. Treatment of hepatic stellate cells with sulfasalazine (0.5-2.0 mmol/L) induced apoptosis of activated rat and human hepatic stellate cells. A single in vivo administration of sulfasalazine promoted accelerated recovery from fibrosis as assessed by improved fibrosis score, selective clearance of smooth muscle alpha-actin-positive myofibroblasts, reduced hepatic procollagen I and tissue inhibitor of metalloproteinase 1 messenger RNA expression, and increased matrix metalloproteinase 2 activity. Mechanistic studies showed that sulfasalazine selectively blocks nuclear factor-kappaB-dependent gene transcription, inhibits hepatic stellate cell expression of Gadd45beta, stimulates phosphorylation of Jun N-terminal kinase 2, and promotes apoptosis by a mechanism that is prevented by the Jun N-terminal kinase inhibitor SP600125. As further evidence for a survival role for the inhibitor of kappaB kinase/nuclear factor-kappaB pathway in activated hepatic stellate cells, a highly selective cell-permeable peptide inhibitor of kappaB kinase activation also stimulated hepatic stellate cell apoptosis via a Jun N-terminal kinase-dependent mechanism. Inhibition of the inhibitor of kappaB kinase/nuclear factor-kappaB pathway is sufficient to increase the rate at which activated hepatic stellate cells undergo apoptosis both in vitro and in vivo, and drugs that

  16. Dual host specificity of phage SP6 is facilitated by tailspike rotation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tu, Jiagang

    Bacteriophage SP6 exhibits dual-host adsorption specificity. The SP6 tailspikes are recognized as important in host range determination but the mechanisms underlying dual host specificity are unknown. Cryo-electron tomography and sub-tomogram classification were used to analyze the SP6 virion with a particular focus on the interaction of tailspikes with host membranes. The SP6 tail is surrounded by six V-shaped structures that interconnect in forming a hand-over-hand hexameric garland. Each V-shaped structure consists of two trimeric tailspike proteins: gp46 and gp47, connected through the adaptor protein gp37. SP6 infection of Salmonella enterica serovars Typhimurium and Newport results in distinguishable changes in tailspikemore » orientation, providing the first direct demonstration how tailspikes can confer dual host adsorption specificity. SP6 also infects S. Typhimurium strains lacking O antigen; in these infections tailspikes have no apparent specific role and the phage tail must therefore interact with a distinct host receptor to allow infection. - Highlights: •Cryo-electron tomography reveals the structural basis for dual host specificity. •Sub-tomogram classification reveals distinct orientations of the tailspikes during infection of different hosts. •Tailspike-adaptor modules rotate as they bind different O antigens. •In the absence of any O antigen, tailspikes bind weakly and without specificity to LPS. •Interaction of the phage tail with LPS is essential for infection.« less

  17. The murine SP-C promoter directs type II cell-specific expression in transgenic mice.

    PubMed

    Glasser, Stephan W; Eszterhas, Susan K; Detmer, Emily A; Maxfield, Melissa D; Korfhagen, Thomas R

    2005-04-01

    Genomic DNA from the mouse pulmonary surfactant protein C (SP-C) gene was analyzed in transgenic mice to identify DNA essential for alveolar type II cell-specific expression. SP-C promoter constructs extending either 13 or 4.8 kb upstream of the transcription start site directed lung-specific expression of the bacterial chloramphenicol acetyl transferase (CAT) reporter gene. In situ hybridization analysis demonstrated alveolar cell-specific expression in the lungs of adult transgenic mice, and the pattern of 4.8 SP-C-CAT expression during development paralleled that of the endogenous SP-C gene. With the use of deletion constructs, lung-specific, low-level CAT activity was detected in tissue assays of SP-C-CAT transgenic mice retaining 318 bp of the promoter. In transient and stable cell transfection experiments, the 4.8-kb SP-C promoter was 90-fold more active as a stably integrated gene. These findings indicate that 1) the 4.8-kb SP-C promoter is sufficient to direct cell-specific and developmental expression, 2) an enhancer essential for lung-specific expression maps to the proximal 318-bp promoter, and 3) the activity of the 4.8-kb SP-C promoter construct is highly dependent on its chromatin environment.

  18. Procyanidins from Wild Grape (Vitis amurensis) Seeds Regulate ARE-Mediated Enzyme Expression via Nrf2 Coupled with p38 and PI3K/Akt Pathway in HepG2 Cells

    PubMed Central

    Bak, Min-Ji; Jun, Mira; Jeong, Woo-Sik

    2012-01-01

    Procyanidins, polymers of flavan-3-ol units, have been reported to exhibit many beneficial health effects such as antioxidant and anti-carcinogenic effects. In this study, we investigated the cancer chemopreventive properties of procyanidins from wild grape (Vitis amurensis) seeds in particular their roles in inducing phase II detoxifying/antioxidant enzymes as well as in modulating the upstream kinases. Ethanolic extract of V. amurensis seeds was fractionated with a series of organic solvents and finally separated into six fractions, F1–F6. Chemical properties of the procyanidins were analyzed by vanillin assay, BuOH-HCl test, and depolymerization with phloroglucinol followed by LC/MS analysis. The F5 had the highest procyanidin content among all the fractions and strongly induced the reporter activity of antioxidant response element as well as the protein expression of nuclear factor E2-related factor (Nrf2) in HepG2 human hepatocarcinoma cells. The procyanidin-rich F5 also strongly induced the expression of the phase II detoxifying and antioxidant enzymes such as NAD(P)H:quinone oxidoreductase1 and hemeoxygenase1. Phosphorylations of the upstream kinases such as MAPKs and PI3K/Akt were significantly increased by treatment with procyanidin fraction. In addition, the procyanidin-mediated Nrf2 expression was partly attenuated by PI3K inhibitor LY294002, and almost completely by p38 inhibitor SB202190, but neither by JNK inhibitor SP600125 nor by MEK1/2 inhibitor U0126. Taken together, the procyanidins from wild grape seeds could be used as a potential natural chemopreventive agent through Nrf2/ARE-mediated phase II detoxifying/antioxidant enzymes induction via p38 and PI3K/Akt pathway. PMID:22312287

  19. Hexylitaconic acid: a new inhibitor of p53-HDM2 interaction isolated from a marine-derived fungus, Arthrinium sp.

    PubMed

    Tsukamoto, Sachiko; Yoshida, Takushi; Hosono, Hidetaka; Ohta, Tomihisa; Yokosawa, Hideyoshi

    2006-01-01

    A new inhibitor of p53-HDM2 interaction was isolated from a culture of marine-derived fungus, Arthrinium sp. The structure was identified to be (-)-hexylitaconic acid (1) by spectroscopic analysis. The inhibition of p53-HDM2 binding was tested by the ELISA method, and 1 inhibited the binding with an IC(50) value of 50 microg/mL. Although a number of synthetic inhibitors of p53-HDM2 interaction have been reported so far, 1 is the second inhibitor isolated from natural resources.

  20. Amyloid precursor protein modulates Nav1.6 sodium channel currents through a Go-coupled JNK pathway.

    PubMed

    Li, Shao; Wang, Xi; Ma, Quan-Hong; Yang, Wu-Lin; Zhang, Xiao-Gang; Dawe, Gavin S; Xiao, Zhi-Cheng

    2016-12-23

    Amyloid precursor protein (APP), commonly associated with Alzheimer's disease, also marks axonal degeneration. In the recent studies, we demonstrated that APP aggregated at nodes of Ranvier (NORs) in myelinated central nervous system (CNS) axons and interacted with Nav1.6. However, the physiological function of APP remains unknown. In this study, we described reduced sodium current densities in APP knockout hippocampal neurons. Coexpression of APP or its intracellular domains containing a VTPEER motif with Na v 1.6 sodium channels in Xenopus oocytes resulted in an increase in peak sodium currents, which was enhanced by constitutively active Go mutant and blocked by a dominant negative mutant. JNK and CDK5 inhibitor attenuated increases in Nav1.6 sodium currents induced by overexpression of APP. Nav1.6 sodium currents were increased by APPT668E (mutant Thr to Glu) and decreased by T668A (mutant Thr to ALa) mutant, respectively. The cell surface expression of Nav1.6 sodium channels in the white matter of spinal cord and the spinal conduction velocity is decreased in APP, p35 and JNK3 knockout mice. Therefore, APP modulates Nav1.6 sodium channels through a Go-coupled JNK pathway, which is dependent on phosphorylation of APP at Thr668.

  1. Amyloid precursor protein modulates Nav1.6 sodium channel currents through a Go-coupled JNK pathway

    PubMed Central

    Li, Shao; Wang, Xi; Ma, Quan-Hong; Yang, Wu-lin; Zhang, Xiao-Gang; Dawe, Gavin S.; Xiao, Zhi-Cheng

    2016-01-01

    Amyloid precursor protein (APP), commonly associated with Alzheimer’s disease, also marks axonal degeneration. In the recent studies, we demonstrated that APP aggregated at nodes of Ranvier (NORs) in myelinated central nervous system (CNS) axons and interacted with Nav1.6. However, the physiological function of APP remains unknown. In this study, we described reduced sodium current densities in APP knockout hippocampal neurons. Coexpression of APP or its intracellular domains containing a VTPEER motif with Nav1.6 sodium channels in Xenopus oocytes resulted in an increase in peak sodium currents, which was enhanced by constitutively active Go mutant and blocked by a dominant negative mutant. JNK and CDK5 inhibitor attenuated increases in Nav1.6 sodium currents induced by overexpression of APP. Nav1.6 sodium currents were increased by APPT668E (mutant Thr to Glu) and decreased by T668A (mutant Thr to ALa) mutant, respectively. The cell surface expression of Nav1.6 sodium channels in the white matter of spinal cord and the spinal conduction velocity is decreased in APP, p35 and JNK3 knockout mice. Therefore, APP modulates Nav1.6 sodium channels through a Go-coupled JNK pathway, which is dependent on phosphorylation of APP at Thr668. PMID:28008944

  2. Activation of the HMGB1-RAGE axis upregulates TH expression in dopaminergic neurons via JNK phosphorylation.

    PubMed

    Kim, Soo Jeong; Ryu, Min Jeong; Han, Jeongsu; Jang, Yunseon; Kim, Jungim; Lee, Min Joung; Ryu, Ilhwan; Ju, Xianshu; Oh, Eungseok; Chung, Woosuk; Kweon, Gi Ryang; Heo, Jun Young

    2017-11-04

    The derangement of tyrosine hydroxylase (TH) activity reduces dopamine synthesis and is implicated in the pathogenesis of Parkinson's disease. However, the extracellular modulator and intracellular regulatory mechanisms of TH have yet to be identified. Recently, high-mobility group box 1 (HMGB1) was reported to be actively secreted from glial cells and is regarded as a mediator of dopaminergic neuronal loss. However, the mechanism for how HMGB1 affects TH expression, particularly through the receptor for advanced glycation endproducts (RAGE), has not yet been investigated. We found that recombinant HMGB1 (rHMGB1) upregulates TH mRNA expression via simultaneous activation of JNK phosphorylation, and this induction of TH expression is blocked by inhibitors of RAGE and JNK. To investigate how TH expression levels change through the HMGB1-RAGE axis as a result of MPP + toxicity, we co-treated SN4741 dopaminergic cells with MPP + and rHMGB1. rHMGB1 blocked the reduction of TH mRNA following MPP + treatment without altering cell survival rates. Our results suggest that HMGB1 upregulates TH expression to maintain dopaminergic neuronal function via activating RAGE, which is dependent on JNK phosphorylation. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. JIP1-Mediated JNK Activation Negatively Regulates Synaptic Plasticity and Spatial Memory.

    PubMed

    Morel, Caroline; Sherrin, Tessi; Kennedy, Norman J; Forest, Kelly H; Avcioglu Barutcu, Seda; Robles, Michael; Carpenter-Hyland, Ezekiel; Alfulaij, Naghum; Standen, Claire L; Nichols, Robert A; Benveniste, Morris; Davis, Roger J; Todorovic, Cedomir

    2018-04-11

    The c-Jun N-terminal kinase (JNK) signal transduction pathway is implicated in learning and memory. Here, we examined the role of JNK activation mediated by the JNK-interacting protein 1 (JIP1) scaffold protein. We compared male wild-type mice with a mouse model harboring a point mutation in the Jip1 gene that selectively blocks JIP1-mediated JNK activation. These male mutant mice exhibited increased NMDAR currents, increased NMDAR-mediated gene expression, and a lower threshold for induction of hippocampal long-term potentiation. The JIP1 mutant mice also displayed improved hippocampus-dependent spatial memory and enhanced associative fear conditioning. These results were confirmed using a second JIP1 mutant mouse model that suppresses JNK activity. Together, these observations establish that JIP1-mediated JNK activation contributes to the regulation of hippocampus-dependent, NMDAR-mediated synaptic plasticity and learning. SIGNIFICANCE STATEMENT The results of this study demonstrate that c-Jun N-terminal kinase (JNK) activation induced by the JNK-interacting protein 1 (JIP1) scaffold protein negatively regulates the threshold for induction of long-term synaptic plasticity through the NMDA-type glutamate receptor. This change in plasticity threshold influences learning. Indeed, mice with defects in JIP1-mediated JNK activation display enhanced memory in hippocampus-dependent tasks, such as contextual fear conditioning and Morris water maze, indicating that JIP1-JNK constrains spatial memory. This study identifies JIP1-mediated JNK activation as a novel molecular pathway that negatively regulates NMDAR-dependent synaptic plasticity and memory. Copyright © 2018 the authors 0270-6474/18/383708-21$15.00/0.

  4. tPA variant tPA-A296-299 Prevents impairment of cerebral autoregulation and necrosis of hippocampal neurons after stroke by inhibiting upregulation of ET-1.

    PubMed

    Armstead, William M; Hekierski, Hugh; Yarovoi, Serge; Higazi, Abd Al-Roof; Cines, Douglas B

    2018-01-01

    Tissue-type plasminogen activator (tPA) is neurotoxic and exacerbates uncoupling of cerebral blood flow (CBF) and metabolism after stroke, yet it remains the sole FDA-approved drug for treatment of ischemic stroke. Upregulation of c-Jun-terminal kinase (JNK) after stroke contributes to tPA-mediated impairment of autoregulation, but the role of endothelin-1 (ET-1) is unknown. Based on the Glasgow Coma Scale, impaired autoregulation is linked to adverse outcomes after TBI, but correlation with hippocampal histopathology after stroke has not been established. We propose that given after stroke, tPA activates N-Methyl-D-Aspartate receptors (NMDA-Rs) and upregulates ET-1 in a JNK dependent manner, imparing autoregulation and leading to histopathology. After stroke, CBF was reduced in the hippocampus and reduced further during hypotension, which did not occur in hypotensive sham pigs, indicating impairment of autoregulation. Autoregulation and necrosis of hippocampal CA1 and CA3 neurons were further impaired by tPA, but were preserved by the ET-1 antagonist BQ 123 and tPA-A, 296-299 a variant that is fibrinolytic but does not bind to NMDA-Rs. Expression of ET-1 was increased by stroke and potentiated by tPA but returned to sham levels by tPA-A 296-299 and the JNK antagonist SP600125. Results show that JNK releases ET-1 after stroke. Tissue-type plasminogen activator -A 296-299 prevents impairment of cerebral autoregulation and histopathology after stroke by inhibiting upregulation of ET-1. © 2017 Wiley Periodicals, Inc.

  5. Downregulation of Ras C-terminal processing by JNK inhibition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mouri, Wataru; Department of Neurosurgery, Yamagata University School of Medicine, Yamagata 990-9585; Biology Division, National Cancer Center Research Institute, Tokyo 104-0045

    2008-06-27

    After translation, Ras proteins undergo a series of modifications at their C-termini. This post-translational C-terminal processing is essential for Ras to become functional, but it remains unknown whether and how Ras C-terminal processing is regulated. Here we show that the C-terminal processing and subsequent plasma membrane localization of H-Ras as well as the activation of the downstream signaling pathways by H-Ras are prevented by JNK inhibition. Conversely, JNK activation by ultraviolet irradiation resulted in promotion of C-terminal processing of H-Ras. Furthermore, increased cell density promoted C-terminal processing of H-Ras most likely through an autocrine/paracrine mechanism, which was also blocked undermore » JNK-inhibited condition. Ras C-terminal processing was sensitive to JNK inhibition in the case of H- and N-Ras but not K-Ras, and in a variety of cell types. Thus, our results suggest for the first time that Ras C-terminal processing is a regulated mechanism in which JNK is involved.« less

  6. Sargassum fusiforme fraction is a potent and specific inhibitor of HIV-1 fusion and reverse transcriptase

    PubMed Central

    Paskaleva, Elena E; Lin, Xudong; Duus, Karen; McSharry, James J; Veille, Jean-Claude L; Thornber, Carol; Liu, Yanze; Lee, David Yu-Wei; Canki, Mario

    2008-01-01

    Sargassum fusiforme (Harvey) Setchell has been shown to be a highly effective inhibitor of HIV-1 infection. To identify its mechanism of action, we performed bioactivity-guided fractionation on Sargassum fusiforme mixture. Here, we report isolation of a bioactive fraction SP4-2 (S. fusiforme), which at 8 μg/ml inhibited HIV-1 infection by 86.9%, with IC50 value of 3.7 μg. That represents 230-fold enhancement of antiretroviral potency as compared to the whole extract. Inhibition was mediated against both CXCR4 (X4) and CCR5 (R5) tropic HIV-1. Specifically, 10 μg/ml SP4-2 blocked HIV-1 fusion and entry by 53%. This effect was reversed by interaction of SP4-2 with sCD4, suggesting that S. fusiforme inhibits HIV-1 infection by blocking CD4 receptor, which also explained observed inhibition of both X4 and R5-tropic HIV-1. SP4-2 also inhibited HIV-1 replication after virus entry, by directly inhibiting HIV-1 reverse transcriptase (RT) in a dose dependent manner by up to 79%. We conclude that the SP4-2 fraction contains at least two distinct and biologically active molecules, one that inhibits HIV-1 fusion by interacting with CD4 receptor, and another that directly inhibits HIV-1 RT. We propose that S. fusiforme is a lead candidate for anti-HIV-1 drug development. PMID:18197976

  7. TSG-6 secreted by human umbilical cord-MSCs attenuates severe burn-induced excessive inflammation via inhibiting activations of P38 and JNK signaling.

    PubMed

    Liu, Lingying; Song, Huifeng; Duan, Hongjie; Chai, Jiake; Yang, Jing; Li, Xiao; Yu, Yonghui; Zhang, Xulong; Hu, Xiaohong; Xiao, Mengjing; Feng, Rui; Yin, Huinan; Hu, Quan; Yang, Longlong; Du, Jundong; Li, Tianran

    2016-07-22

    The hMSCs have become a promising approach for inflammation treatment in acute phase. Our previous study has demonstrated that human umbilical cord-MSCs could alleviate the inflammatory reaction of severely burned wound. In this study, we further investigated the potential role and mechanism of the MSCs on severe burn-induced excessive inflammation. Wistar rats were randomly divided into following groups: Sham, Burn, Burn+MSCs, Burn+MAPKs inhibitors, and Burn, Burn+MSCs, Burn+Vehicle, Burn+siTSG-6, Burn+rhTSG-6 in the both experiments. It was found that MSCs could only down-regulate P38 and JNK signaling, but had no effect on ERK in peritoneal macrophages of severe burn rats. Furthermore, suppression of P38 and JNK activations significantly reduced the excessive inflammation induced by severe burn. TSG-6 was secreted by MSCs using different inflammatory mediators. TSG-6 from MSCs and recombinant human (rh)TSG-6 all significantly reduced activations of P38 and JNK signaling induced by severe burn and then attenuated excessive inflammations. On the contrary, knockdown TSG-6 in the cells significantly increased phosphorylation of P38 and JNK signaling and reduced therapeutic effect of the MSCs on excessive inflammation. Taken together, this study suggested TSG-6 from MSCs attenuated severe burn-induced excessive inflammation via inhibiting activation of P38 and JNK signaling.

  8. Sp100 isoform-specific regulation of human adenovirus 5 gene expression.

    PubMed

    Berscheminski, Julia; Wimmer, Peter; Brun, Juliane; Ip, Wing Hang; Groitl, Peter; Horlacher, Tim; Jaffray, Ellis; Hay, Ron T; Dobner, Thomas; Schreiner, Sabrina

    2014-06-01

    Promyelocytic leukemia nuclear bodies (PML-NBs) are nuclear structures that accumulate intrinsic host factors to restrict viral infections. To ensure viral replication, these must be limited by expression of viral early regulatory proteins that functionally inhibit PML-NB-associated antiviral effects. To benefit from the activating capabilities of Sp100A and simultaneously limit repression by Sp100B, -C, and -HMG, adenoviruses (Ads) employ several features to selectively and individually target these isoforms. Ads induce relocalization of Sp100B, -C, and -HMG from PML-NBs prior to association with viral replication centers. In contrast, Sp100A is kept at the PML tracks that surround the newly formed viral replication centers as designated sites of active transcription. We concluded that the host restriction factors Sp100B, -C, and -HMG are potentially inactivated by active displacement from these sites, whereas Sp100A is retained to amplify Ad gene expression. Ad-dependent loss of Sp100 SUMOylation is another crucial part of the virus repertoire to counteract intrinsic immunity by circumventing Sp100 association with HP1, therefore limiting chromatin condensation. We provide evidence that Ad selectively counteracts antiviral responses and, at the same time, benefits from PML-NB-associated components which support viral gene expression by actively recruiting them to PML track-like structures. Our findings provide insights into novel strategies for manipulating transcriptional regulation to either inactivate or amplify viral gene expression. We describe an adenoviral evasion strategy that involves isoform-specific and active manipulation of the PML-associated restriction factor Sp100. Recently, we reported that the adenoviral transactivator E1A targets PML-II to efficiently activate viral transcription. In contrast, the PML-associated proteins Daxx and ATRX are inhibited by early viral factors. We show that this concept is more intricate and significant than

  9. The adaptor protein Cindr regulates JNK activity to maintain epithelial sheet integrity.

    PubMed

    Yasin, Hannah W R; van Rensburg, Samuel H; Feiler, Christina E; Johnson, Ruth I

    2016-02-15

    Epithelia are essential barrier tissues that must be appropriately maintained for their correct function. To achieve this a plethora of protein interactions regulate epithelial cell number, structure and adhesion, and differentiation. Here we show that Cindr (the Drosophila Cin85 and Cd2ap ortholog) is required to maintain epithelial integrity. Reducing Cindr triggered cell delamination and movement. Most delaminating cells died. These behaviors were consistent with JNK activation previously associated with loss of epithelial integrity in response to ectopic oncogene activity. We confirmed a novel interaction between Cindr and Drosophila JNK (dJNK), which when perturbed caused inappropriate JNK signaling. Genetically reducing JNK signaling activity suppressed the effects of reducing Cindr. Furthermore, ectopic JNK signaling phenocopied loss of Cindr and was partially rescued by concomitant cindr over-expression. Thus, correct Cindr-dJNK stoichiometry is essential to maintain epithelial integrity and disturbing this balance may contribute to the pathogenesis of disease states, including cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Activation of neurokinin-1 receptors up-regulates substance P and neurokinin-1 receptor expression in murine pancreatic acinar cells.

    PubMed

    Koh, Yung-Hua; Moochhala, Shabbir; Bhatia, Madhav

    2012-07-01

    Acute pancreatitis (AP) has been associated with an up-regulation of substance P (SP) and neurokinin-1 receptor (NK1R) in the pancreas. Increased SP-NK1R interaction was suggested to be pro-inflammatory during AP. Previously, we showed that caerulein treatment increased SP/NK1R expression in mouse pancreatic acinar cells, but the effect of SP treatment was not evaluated. Pancreatic acinar cells were obtained from pancreas of male swiss mice (25-30 g). We measured mRNA expression of preprotachykinin-A (PPTA) and NK1R following treatment of SP (10(-6) M). SP treatment increased PPTA and NK1R expression in isolated pancreatic acinar cells, which was abolished by pretreatment of a selective NK1R antagonist, CP96,345. SP also time dependently increased protein expression of NK1R. Treatment of cells with a specific NK1R agonist, GR73,632, up-regulated SP protein levels in the cells. Using previously established concentrations, pre-treatment of pancreatic acinar cells with Gö6976 (10 nM), rottlerin (5 μM), PD98059 (30 μM), SP600125 (30 μM) or Bay11-7082 (30 μM) significantly inhibited up-regulation of SP and NK1R. These observations suggested that the PKC-ERK/JNK-NF-κB pathway is necessary for the modulation of expression levels. In comparison, pre-treatment of CP96,345 reversed gene expression in SP-induced cells, but not in caerulein-treated cells. Overall, the findings in this study suggested a possible auto-regulatory mechanism of SP/NK1R expression in mouse pancreatic acinar cells, via activation of NK1R. Elevated SP levels during AP might increase the occurrence of a positive feedback loop that contributes to abnormally high expression of SP and NK1R. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  11. TP53 mutation-correlated genes predict the risk of tumor relapse and identify MPS1 as a potential therapeutic kinase in TP53-mutated breast cancers.

    PubMed

    Győrffy, Balázs; Bottai, Giulia; Lehmann-Che, Jacqueline; Kéri, György; Orfi, László; Iwamoto, Takayuki; Desmedt, Christine; Bianchini, Giampaolo; Turner, Nicholas C; de Thè, Hugues; André, Fabrice; Sotiriou, Christos; Hortobagyi, Gabriel N; Di Leo, Angelo; Pusztai, Lajos; Santarpia, Libero

    2014-05-01

    Breast cancers (BC) carry a complex set of gene mutations that can influence their gene expression and clinical behavior. We aimed to identify genes driven by the TP53 mutation status and assess their clinical relevance in estrogen receptor (ER)-positive and ER-negative BC, and their potential as targets for patients with TP53 mutated tumors. Separate ROC analyses of each gene expression according to TP53 mutation status were performed. The prognostic value of genes with the highest AUC were assessed in a large dataset of untreated, and neoadjuvant chemotherapy treated patients. The mitotic checkpoint gene MPS1 was the most significant gene correlated with TP53 status, and the most significant prognostic marker in all ER-positive BC datasets. MPS1 retained its prognostic value independently from the type of treatment administered. The biological functions of MPS1 were investigated in different BC cell lines. We also assessed the effects of a potent small molecule inhibitor of MPS1, SP600125, alone and in combination with chemotherapy. Consistent with the gene expression profiling and siRNA assays, the inhibition of MPS1 by SP600125 led to a reduction in cell viability and a significant increase in cell death, selectively in TP53-mutated BC cells. Furthermore, the chemical inhibition of MPS1 sensitized BC cells to conventional chemotherapy, particularly taxanes. Our results collectively demonstrate that TP53-correlated kinase MPS1, is a potential therapeutic target in BC patients with TP53 mutated tumors, and that SP600125 warrant further development in future clinical trials. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  12. Cannabinoid Receptor 2 Suppresses Leukocyte Inflammatory Migration by Modulating the JNK/c-Jun/Alox5 Pathway*

    PubMed Central

    Liu, Yi-Jie; Fan, Hong-Bo; Jin, Yi; Ren, Chun-Guang; Jia, Xiao-E; Wang, Lei; Chen, Yi; Dong, Mei; Zhu, Kang-Yong; Dong, Zhi-Wei; Ye, Bai-Xin; Zhong, Zhong; Deng, Min; Liu, Ting Xi; Ren, Ruibao

    2013-01-01

    Inflammatory migration of immune cells is involved in many human diseases. Identification of molecular pathways and modulators controlling inflammatory migration could lead to therapeutic strategies for treating human inflammation-associated diseases. The role of cannabinoid receptor type 2 (Cnr2) in regulating immune function had been widely investigated, but the mechanism is not fully understood. Through a chemical genetic screen using a zebrafish model for leukocyte migration, we found that both an agonist of the Cnr2 and inhibitor of the 5-lipoxygenase (Alox5, encoded by alox5) inhibit leukocyte migration in response to acute injury. These agents have a similar effect on migration of human myeloid cells. Consistent with these results, we found that inactivation of Cnr2 by zinc finger nuclease-mediated mutagenesis enhances leukocyte migration, while inactivation of Alox5 blocks leukocyte migration. Further investigation indicates that there is a signaling link between Cnr2 and Alox5 and that alox5 is a target of c-Jun. Cnr2 activation down-regulates alox5 expression by suppressing the JNK/c-Jun activation. These studies demonstrate that Cnr2, JNK, and Alox5 constitute a pathway regulating leukocyte migration. The cooperative effect between the Cnr2 agonist and Alox5 inhibitor also provides a potential therapeutic strategy for treating human inflammation-associated diseases. PMID:23539630

  13. Magnolol reduced TNF-α-induced vascular cell adhesion molecule-1 expression in endothelial cells via JNK/p38 and NF-κB signaling pathways.

    PubMed

    Liang, Chan-Jung; Lee, Chiang-Wen; Sung, Hsin-Ching; Chen, Yung-Hsiang; Wang, Shu-Huei; Wu, Pei-Jhen; Chiang, Yao-Chang; Tsai, Jaw-Shiun; Wu, Chau-Chung; Li, Chi-Yuan; Chen, Yuh-Lien

    2014-01-01

    Expression of cell adhesion molecules by the endothelium and the attachment of leukocytes to these cells play major roles in inflammation and cardiovascular disorders. Magnolol, a major active component of Magnolia officinalis, has antioxidative and anti-inflammatory properties. In the present study, the effects of magnolol on the expression of vascular cell adhesion molecule-1 (VCAM-1) in human aortic endothelial cells (HAECs) and the related mechanisms were investigated. TNF-α induced VCAM-1 protein expression and mRNA stability were significantly decreased in HAECs pre-treated with magnolol. Magnolol significantly reduced the phosphorylation of ERK, JNK, and p38 in TNF-α-treated HAECs. The decrease in VCAM-1 expression in response to TNF-α treatment was affected by JNK and p38 inhibitors, not by an ERK inhibitor. Magnolol also attenuates NF-κB activation and the translocation of HuR (an RNA binding protein) in TNF-α-stimulated HAECs. The VCAM-1 expression was weaker in the aortas of TNF-α-treated apo-E deficient mice with magnolol treatment. These data demonstrate that magnolol inhibits TNF-α-induced JNK/p38 phosphorylation, HuR translocation, NF-κB activation, and thereby suppresses VCAM-1 expression resulting in reduced leukocyte adhesion. Taken together, these results suggest that magnolol has an anti-inflammatory property and may play an important role in the prevention of atherosclerosis and inflammatory responses.

  14. Titanium dioxide nanoparticles increase inflammatory responses in vascular endothelial cells

    PubMed Central

    Han, Sung Gu; Newsome, Bradley; Hennig, Bernhard

    2013-01-01

    Atherosclerosis is a chronic inflammatory disease that remains the leading cause of death in the United States. Numerous risk factors for endothelial cell inflammation and the development of atherosclerosis have been identified, including inhalation of ultrafine particles. Recently, engineered nanoparticles (NPs) such as titanium (TiO2) NPs have attracted much attention due to their wide range of applications. However, there are also great concerns surrounding potential adverse health effects in vascular systems. Although TiO2 NPs are known to induce oxidative stress and inflammation, the associated signaling pathways have not been well studied. The focus of this work, therefore, deals with examination of the cellular signaling pathways responsible for TiO2 NP-induced endothelial oxidative stress and inflammation. In this study, primary vascular endothelial cells were treated with TiO2 NPs for 2–16 h at concentrations of 0–50 µg/mL. TiO2 NP exposure increased cellular oxidative stress and DNA binding of NF-κB. Further, phosphorylation of Akt, ERK, JNK and p38 was increased in cells exposed to TiO2 NPs. TiO2 NPs also significantly increased induction of mRNA and protein levels of vascular cell adhesion molecule-1 (VCAM-1) and mRNA levels of monocyte chemoattractant protein-1 (MCP-1). Pretreatment with inhibitors for NF-κB (pyrrolidine dithiocarbamate), oxidative stress (epigallocatechin gallate and apocynin), Akt (LY294002), ERK (PD98059), JNK (SP600125) and p38 (SB203580) significantly attenuated TiO2 NP-induced MCP-1 and VCAM-1 gene expression, as well as activation of NF-κB. These data indicate that TiO2 NPs can induce endothelial inflammatory responses via redox-sensitive cellular signaling pathways. PMID:23380242

  15. Lymphomagenic CARD11/BCL10/MALT1 signaling drives malignant B-cell proliferation via cooperative NF-κB and JNK activation.

    PubMed

    Knies, Nathalie; Alankus, Begüm; Weilemann, Andre; Tzankov, Alexandar; Brunner, Kristina; Ruff, Tanja; Kremer, Marcus; Keller, Ulrich B; Lenz, Georg; Ruland, Jürgen

    2015-12-29

    The aggressive activated B cell-like subtype of diffuse large B-cell lymphoma is characterized by aberrant B-cell receptor (BCR) signaling and constitutive nuclear factor kappa-B (NF-κB) activation, which is required for tumor cell survival. BCR-induced NF-κB activation requires caspase recruitment domain-containing protein 11 (CARD11), and CARD11 gain-of-function mutations are recurrently detected in human diffuse large B-cell lymphoma (DLBCL). To investigate the consequences of dysregulated CARD11 signaling in vivo, we generated mice that conditionally express the human DLBCL-derived CARD11(L225LI) mutant. Surprisingly, CARD11(L225LI) was sufficient to trigger aggressive B-cell lymphoproliferation, leading to early postnatal lethality. CARD11(L225LI) constitutively associated with B-cell CLL/lymphoma 10 (BCL10) and mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1) to simultaneously activate the NF-κB and c-Jun N-terminal kinase (JNK) signaling cascades. Genetic deficiencies of either BCL10 or MALT1 completely rescued the phenotype, and pharmacological inhibition of JNK was, similar to NF-κB blockage, toxic to autonomously proliferating CARD11(L225LI)-expressing B cells. Moreover, constitutive JNK activity was observed in primary human activated B cell-like (ABC)-DLBCL specimens, and human ABC-DLBCL cells were also sensitive to JNK inhibitors. Thus, our results demonstrate that enforced activation of CARD11/BCL10/MALT1 signaling is sufficient to drive transformed B-cell expansion in vivo and identify the JNK pathway as a therapeutic target for ABC-DLBCL.

  16. EF1A1/HSC70 Cooperatively Suppress Brain Endothelial Cell Apoptosis via Regulating JNK Activity.

    PubMed

    Liu, Ying; Jiang, Shu; Yang, Peng-Yuan; Zhang, Yue-Fan; Li, Tie-Jun; Rui, Yao-Cheng

    2016-10-01

    In our previous study, eEF1A1 was identified to be a new target for protecting brain ischemia injury, but the mechanism remains largely unknown. In this study, we screened the downstream cellular protein molecules interacted with eEF1A1 and found mechanism of eEF1A1 in brain ischemia protection. Through co-immunoprecipitation and mass spectrometry for searching the interaction of proteins with eEF1A1 in bEnd3 cells, HSC70 was identified to be a binding protein of eEF1A1, which was further validated by Western blot and immunofluorescence. eEF1A1 or HSC70 knockdown, respectively, increased OGD-induced apoptosis of brain vascular endothelial cells, which was detected by Annexin V-FITC/PI staining. HSC70 or eEF1A1 knockdown enhances phosphorylated JNK, phosphorylation of c-JUN (Ser63, Ser73), cleaved caspase-9, and cleaved caspase-3 expression, which could be rescued by JNK inhibitor. In summary, our data suggest that the presence of chaperone forms of interaction between eEF1A1 and HSC70 in brain vascular endothelial cells, eEF1A1 and HSC70 can play a protective role in the process of ischemic stroke by inhibiting the JNK signaling pathway activation. © 2016 John Wiley & Sons Ltd.

  17. The MAP kinase JNK2 mediates cigarette smoke-induced arterial thrombosis.

    PubMed

    Breitenstein, Alexander; Stämpfli, Simon F; Reiner, Martin F; Shi, Yi; Keller, Stephan; Akhmedov, Alexander; Schaub Clerigué, Ariane; Spescha, Remo D; Beer, Hans-Jürg; Lüscher, Thomas F; Tanner, Felix C; Camici, Giovanni G

    2017-01-05

    Despite public awareness of its deleterious effects, smoking remains a major cause of death. Indeed, it is a risk factor for atherothrombotic complications and in line with this, the introduction of smoking ban in public areas reduced smoking-associated cardiovascular complications. Nonetheless, smoking remains a major concern, and molecular mechanisms by which it causes cardiovascular disease are not known. Peripheral blood monocytes from healthy smokers displayed increased JNK2 and tissue factor (TF) gene expression compared to non-smokers (n=15, p<0.05). Similarly, human aortic endothelial cells exposed to cigarette smoke total particulate matter (CS-TPM) revealed increased TF expression mediated by JNK2 (n=4; p<0.05). Wild-type and JNK2 -/- mice were exposed to cigarette smoke for two weeks after which arterial thrombosis was investigated. Wild-type mice exposed to smoke displayed reduced time to thrombotic arterial occlusion (n=8; p<0.05) and increased tissue factor activity (n=7; p<0.05) as compared to wild-type controls (n=6), while JNK2 -/- mice exposed to smoke maintained an unaltered thrombotic potential (n=8; p=NS) and tissue factor activity (n=8) comparable to that of JNK2 -/- and wild-type controls (n=6; p=NS). Smoking caused an increased production of reactive oxygen species (ROS) in wild-type but not in JNK2 -/- mice (n=7; p<0.05 for wild-type mice and n=5-6; p=NS for JNK2 -/- mice). In conclusion, the MAP kinase JNK2 mediates cigarette smoke-induced TF activation, arterial thrombosis and ROS production. These results underscore a major role of JNK2 in smoke-mediated thrombus formation and may offer an attractive target to prevent smoke-related thrombosis in those subjects which do not manage quitting.

  18. c-Jun localizes to the nucleus independent of its phosphorylation by and interaction with JNK and vice versa promotes nuclear accumulation of JNK

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schreck, Ilona; Al-Rawi, Marco; Mingot, Jose-Manuel

    2011-04-22

    Highlights: {yields} HSP70, Ku70 and 80 as well as importin 8 are novel interactors of c-Jun. {yields} Nuclear accumulation of c-Jun does not require its functions as a transcription factor. {yields} Nuclear accumulation of c-Jun does not require the interaction with its kinase JNK. {yields} Nuclear accumulation of JNK is regulated by interaction with c-Jun. -- Abstract: In order to activate gene expression, transcription factors such as c-Jun have to reside in the nucleus. The abundance of c-Jun in the nucleus correlates with the activity of its target genes. As a consequence of excessive c-Jun activation, cells undergo apoptosis ormore » changes in differentiation whereas decreased c-Jun function can reduce proliferation. In the present study we addressed how nuclear accumulation of the transcription factor c-Jun is regulated. First, we analyzed which functions of c-Jun are required for efficient nuclear accumulation. Mutants of c-Jun deficient in dimerization or DNA-binding show no defect in nuclear transport. Furthermore, c-Jun import into the nucleus of living cells occurred when the c-Jun phosphorylation sites were mutated as well in cells that lack the major c-Jun kinase, JNK, suggesting that c-Jun transport into the nucleus does not require JNK signaling. Conversely, however, binding of c-Jun seemed to enhance nuclear accumulation of JNK. In order to identify proteins that might be relevant for the nuclear translocation of c-Jun we searched for novel binding partners by a proteomic approach. In addition to the heat shock protein HSP70 and the DNA damage repair factors Ku70 and 80, we isolated human importin 8 as a novel interactor of c-Jun. Interaction of Imp 8 with c-Jun in human cells was confirmed by co-immunoprecipitation experiments. Nuclear accumulation of c-Jun does not require its functions as a transcription factor or the interaction with its kinase JNK. Interestingly, nuclear accumulation of JNK is regulated by interaction with c-Jun. Unraveling

  19. Role of JNK isoforms in the kainic acid experimental model of epilepsy and neurodegeneration.

    PubMed

    Auladell, Carme; de Lemos, Luisa; Verdaguer, Ester; Ettcheto, Miren; Busquets, Oriol; Lazarowski, Alberto; Beas-Zarate, Carlos; Olloquequi, Jordi; Folch, Jaume; Camins, Antoni

    2017-01-01

    Chemoconvulsants that induce status epilepticus in rodents have been widely used over the past decades due to their capacity to reproduce with high similarity neuropathological and electroencephalographic features observed in patients with temporal lobe epilepsy (TLE). Kainic acid  is one of the most used chemoconvulsants in experimental models. KA administration mainly induces neuronal loss in the hippocampus. We focused the present review inthe c-Jun N-terminal kinase-signaling pathway (JNK), since it has been shown to play a key role in the process of neuronal death following KA activation. Among the three isoforms of JNK (JNK1, JNK2, JNK3), JNK3 is widely localized in the majority of areas of the hippocampus, whereas JNK1 levels are located exclusively in the CA3 and CA4 areas and in dentate gyrus. Disruption of the gene encoding JNK3 in mice renders neuroprotection to KA, since these animals showed a reduction in seizure activity and a diminution in hippocampal neuronal apoptosis. In light of this, JNK3 could be a promising subcellular target for future therapeutic interventions in epilepsy.

  20. TNF{alpha} acting on TNFR1 promotes breast cancer growth via p42/P44 MAPK, JNK, Akt and NF-{kappa}B-dependent pathways

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rivas, Martin A.; Carnevale, Romina P.; Proietti, Cecilia J.

    2008-02-01

    Tumor necrosis factor {alpha} (TNF{alpha}) enhances proliferation of chemically-induced mammary tumors and of T47D human cell line through not fully understood pathways. Here, we explored the intracellular signaling pathways triggered by TNF{alpha}, the participation of TNF{alpha} receptor (TNFR) 1 and TNFR2 and the molecular mechanism leading to breast cancer growth. We demonstrate that TNF{alpha} induced proliferation of C4HD murine mammary tumor cells and of T47D cells through the activation of p42/p44 MAPK, JNK, PI3-K/Akt pathways and nuclear factor-kappaB (NF-{kappa}B) transcriptional activation. A TNF{alpha}-specific mutein selectively binding to TNFR1 induced p42/p44 MAPK, JNK, Akt activation, NF-{kappa}B transcriptional activation and cell proliferation,more » just like wild-type TNF{alpha}, while a mutein selective for TNFR2 induced only p42/p44 MAPK activation. Interestingly, blockage of TNFR1 or TNFR2 with specific antibodies was enough to impair TNF{alpha} signaling and biological effect. Moreover, in vivo TNF{alpha} administration supported C4HD tumor growth. We also demonstrated, for the first time, that injection of a selective inhibitor of NF-{kappa}B activity, Bay 11-7082, resulted in regression of TNF{alpha}-promoted tumor. Bay 11-7082 blocked TNF{alpha} capacity to induce cell proliferation and up-regulation of cyclin D1 and of Bcl-x{sub L}in vivo and in vitro. Our results reveal evidence for TNF{alpha} as a breast tumor promoter, and provide novel data for a future therapeutic approach using TNF{alpha} antagonists and NF-{kappa}B pharmacological inhibitors in established breast cancer treatment.« less

  1. Fluid Shear Stress-Induced JNK Activity Leads to Actin Remodeling for Cell Alignment

    PubMed Central

    Mengistu, Meron; Brotzman, Hannah; Ghadiali, Samir; Lowe-Krentz, Linda

    2012-01-01

    Fluid shear stress (FSS) exerted on endothelial cell surfaces induces actin cytoskeleton remodeling through mechanotransduction. This study was designed to determine whether FSS activates Jun N-terminal kinase (JNK), to examine the spatial and temporal distribution of active JNK relative to the actin cytoskeleton in endothelial cells exposed to different FSS conditions, and to evaluate the effects of active JNK on actin realignment. Exposure to 15 and 20 dyn/cm2 FSS induced higher activity levels of JNK than the lower 2 and 4 dyn/cm2 flow conditions. At the higher FSS treatments, JNK activity increased with increasing exposure time, peaking 30 minutes after flow onset with an 8-fold activity increase compared to cells in static culture. FSS-induced phospho-JNK co-localized with actin filaments at cell peripheries, as well as with stress fibers. Pharmacologically blocking JNK activity altered FSS-induced actin structure and distribution as a response to FSS. Our results indicate that FSS-induced actin remodeling occurs in three phases, and that JNK plays a role in at least one, suggesting that this kinase activity is involved in mechanotransduction from the apical surface to the actin cytoskeleton in endothelial cells. PMID:20626006

  2. Stathmin Mediates Hepatocyte Resistance to Death from Oxidative Stress by down Regulating JNK

    PubMed Central

    Zhao, Enpeng; Amir, Muhammad; Lin, Yu; Czaja, Mark J.

    2014-01-01

    Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK). The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth. PMID:25285524

  3. Airborne fine particulate matter causes murine bronchial hyperreactivity via MAPK pathway-mediated M3 muscarinic receptor upregulation.

    PubMed

    Wang, Rong; Xiao, Xue; Shen, Zhenxing; Cao, Lei; Cao, Yongxiao

    2017-02-01

    Regarding the human health effects, airborne fine particulate matter 2.5 (PM 2.5 ) is an important environmental risk factor. However, the underlying molecular mechanisms are largely unknown. The present study examined the hypothesis that PM 2.5 causes bronchial hyperreactivity by upregulated muscarinic receptors via the mitogen-activated protein kinase (MAPK) pathway. The isolated rat bronchi segments were cultured with different concentration of PM 2.5 for different time. The contractile response of the bronchi segments were recorded by a sensitive myograph. The mRNA and protein expression levels of M 3 muscarinic receptors were studied by quantitative real-time PCR and immunohistochemistry, respectively. The muscarinic receptors agonist, carbachol induced a remarkable contractile response on fresh and DMSO cultured bronchial segments. Compared with the fresh or DMSO culture groups, 1.0 µg/mL of PM 2.5 cultured for 24 h significantly enhanced muscarinic receptor-mediated contractile responses in bronchi with a markedly increased maximal contraction. In addition, the expression levels of mRNA and protein for M 3 muscarinic receptors in bronchi of PM 2.5 group were higher than that of fresh or DMSO culture groups. SB203580 (p38 inhibitor) and U0126 (MEK1/2 inhibitor) significantly inhibited the PM 2.5 -induced enhanced contraction and increased mRNA and protein expression of muscarinic receptors. However, JNK inhibitor SP600125 had no effect on PM 2.5 -induced muscarinic receptor upregulation and bronchial hyperreactivity. In conclusion, airborne PM 2.5 upregulates muscarinic receptors, which causes subsequently bronchial hyperreactivity shown as enhanced contractility in bronchi. This process may be mediated by p38 and MEK1/2 MAPK pathways. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 371-381, 2017. © 2016 Wiley Periodicals, Inc.

  4. Curcumin inhibits VEGF-mediated angiogenesis in human intestinal microvascular endothelial cells through COX-2 and MAPK inhibition.

    PubMed

    Binion, D G; Otterson, M F; Rafiee, P

    2008-11-01

    Angiogenesis, the growth of new blood vessels, is a critical homeostatic mechanism which regulates vascular populations in response to physiological requirements and pathophysiological demand, including chronic inflammation and cancer. The importance of angiogenesis in gastrointestinal chronic inflammation and cancer has been defined, as antiangiogenic therapy has demonstrated benefit in models of inflammatory bowel disease and colon cancer treatment. Curcumin is a natural product undergoing evaluation for the treatment of chronic inflammation, including inflammatory bowel disease (IBD). The effect of curcumin on human intestinal angiogenesis is not defined. The antiangiogenic effect of curcumin on in vitro angiogenesis was examined using primary cultures of human intestinal microvascular endothelial cells (HIMECs), stimulated with vascular endothelial growth factor (VEGF). Curcumin inhibited proliferation, cell migration and tube formation in HIMECs induced by VEGF. Activation of HIMECs by VEGF resulted in enhanced expression of cyclo-oxygenase-2 (COX-2) mRNA, protein and prostaglandin E(2) (PGE(2)) production. Pretreatment of HIMECs with 10 microM curcumin as well as 1 microM NS398, a selective inhibitor of COX-2, resulted in inhibition of COX-2 at the mRNA and protein level and PGE(2) production. Similarly COX-2 expression in HIMECs was significantly inhibited by Jun N-terminal kinase (JNK; SP600125) and p38 mitogen-activated protein kinase (MAPK; SB203580) inhibitors and was reduced by p44/42 MAPK inhibitor (PD098059). Taken together, these data demonstrate an important role for COX-2 in the regulation of angiogenesis in HIMECs via MAPKs. Moreover, curcumin inhibits microvascular endothelial cell angiogenesis through inhibition of COX-2 expression and PGE(2) production, suggesting that this natural product possesses antiangiogenic properties, which warrants further investigation as adjuvant treatment of IBD and cancer.

  5. Carbon monoxide alleviates ethanol-induced oxidative damage and inflammatory stress through activating p38 MAPK pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Yanyan; Gao, Chao; Shi, Yanru

    2013-11-15

    Stress-inducible protein heme oxygenase-1(HO-1) is well-appreciative to counteract oxidative damage and inflammatory stress involving the pathogenesis of alcoholic liver diseases (ALD). The potential role and signaling pathways of HO-1 metabolite carbon monoxide (CO), however, still remained unclear. To explore the precise mechanisms, ethanol-dosed adult male Balb/c mice (5.0 g/kg.bw.) or ethanol-incubated primary rat hepatocytes (100 mmol/L) were pretreated by tricarbonyldichlororuthenium (II) dimmer (CORM-2, 8 mg/kg for mice or 20 μmol/L for hepatocytes), as well as other pharmacological reagents. Our data showed that CO released from HO-1 induction by quercetin prevented ethanol-derived oxidative injury, which was abolished by CO scavenger hemoglobin.more » The protection was mimicked by CORM-2 with the attenuation of GSH depletion, SOD inactivation, MDA overproduction, and the leakage of AST, ALT or LDH in serum and culture medium induced by ethanol. Moreover, CORM-2 injection or incubation stimulated p38 phosphorylation and suppressed abnormal Tnfa and IL-6, accompanying the alleviation of redox imbalance induced by ethanol and aggravated by inflammatory factors. The protective role of CORM-2 was abolished by SB203580 (p38 inhibitor) but not by PD98059 (ERK inhibitor) or SP600125 (JNK inhibitor). Thus, HO-1 released CO prevented ethanol-elicited hepatic oxidative damage and inflammatory stress through activating p38 MAPK pathway, suggesting a potential therapeutic role of gaseous signal molecule on ALD induced by naturally occurring phytochemicals. - Highlights: • CO alleviated ethanol-derived liver oxidative and inflammatory stress in mice. • CO eased ethanol and inflammatory factor-induced oxidative damage in hepatocytes. • The p38 MAPK is a key signaling mechanism for the protective function of CO in ALD.« less

  6. Hippo signaling promotes JNK-dependent cell migration.

    PubMed

    Ma, Xianjue; Wang, Hongxiang; Ji, Jiansong; Xu, Wenyan; Sun, Yihao; Li, Wenzhe; Zhang, Xiaoping; Chen, Juxiang; Xue, Lei

    2017-02-21

    Overwhelming studies show that dysregulation of the Hippo pathway is positively correlated with cell proliferation, growth, and tumorigenesis. Paradoxically, the detailed molecular roles of the Hippo pathway in cell invasion remain debatable. Using a Drosophila invasion model in wing epithelium, we show herein that activated Hippo signaling promotes cell invasion and epithelial-mesenchymal transition through JNK, as inhibition of JNK signaling dramatically blocked Hippo pathway activation-induced matrix metalloproteinase 1 expression and cell invasion. Furthermore, we identify bantam -Rox8 modules as essential components downstream of Yorkie in mediating JNK-dependent cell invasion. Finally, we confirm that YAP (Yes-associated protein) expression negatively regulates TIA1 (Rox8 ortholog) expression and cell invasion in human cancer cells. Together, these findings provide molecular insights into Hippo pathway-mediated cell invasion and also raise a noteworthy concern in therapeutic interventions of Hippo-related cancers, as simply inhibiting Yorkie or YAP activity might paradoxically accelerate cell invasion and metastasis.

  7. Specificity protein, Sp1-mediated increased expression of Prdx6 as a curcumin-induced antioxidant defense in lens epithelial cells against oxidative stress

    PubMed Central

    Chhunchha, B; Fatma, N; Bhargavan, B; Kubo, E; Kumar, A; Singh, D P

    2011-01-01

    Peroxiredoxin 6 (Prdx6) is a pleiotropic oxidative stress-response protein that defends cells against reactive oxygen species (ROS)-induced damage. Curcumin, a naturally occurring agent, has diversified beneficial roles including cytoprotection. Using human lens epithelial cells (hLECs) and Prdx6-deficient cells, we show the evidence that curcumin protects cells by upregulating Prdx6 transcription via invoking specificity protein 1 (Sp1) activity against proapoptotic stimuli. Curcumin enhanced Sp1 and Prdx6 mRNA and protein expression in a concentration-dependent manner, as evidenced by western and real-time PCR analyses, and thereby negatively regulated ROS-mediated apoptosis by blunting ROS expression and lipid peroxidation. Bioinformatic analysis and DNA–protein binding assays disclosed three active Sp1 sites (−19/27, −61/69 and −82/89) in Prdx6 promoter. Co-transfection experiments with Sp1 and Prdx6 promoter–chloramphenicol acetyltransferase (CAT) constructs showed that CAT activity was dramatically increased in LECs or Sp1-deficient cells (SL2). Curcumin treatment of LECs enhanced Sp1 binding to its sites, consistent with curcumin-dependent stimulation of Prdx6 promoter with Sp1 sites and cytoprotection. Notably, disruption of Sp1 sites by point mutagenesis abolished curcumin transactivation of Prdx6. Also, curcumin failed to activate Prdx6 expression in the presence of Sp1 inhibitors, demonstrating that curcumin-mediated increased expression of Prdx6 was dependent on Sp1 activity. Collectively, the study may provide a foundation for developing transcription-based inductive therapy to reinforce endogenous antioxidant defense by using dietary supplements. PMID:22113199

  8. A new strategy for strain improvement of Aurantiochytrium sp. based on heavy-ions mutagenesis and synergistic effects of cold stress and inhibitors of enoyl-ACP reductase.

    PubMed

    Cheng, Yu-Rong; Sun, Zhi-Jie; Cui, Gu-Zhen; Song, Xiaojin; Cui, Qiu

    2016-11-01

    Developing a strain with high docosahexaenoic acid (DHA) yield and stable fermenting-performance is an imperative way to improve DHA production using Aurantiochytrium sp., a microorganism with two fatty acid synthesis pathways: polyketide synthase (PKS) pathway and Type I fatty acid synthase (FAS) pathway. This study investigated the growth and metabolism response of Aurantiochytrium sp. CGMCC 6208 to two inhibitors of enoyl-ACP reductase of Type II FAS pathway (isoniazid and triclosan), and proposed a method of screening high DHA yield Aurantiochytrium sp. strains with heavy ion mutagenesis and pre-selection by synergistic usage of cold stress (4°C) and FAS inhibitors (triclosan and isoniazid). Results showed that (1) isoniazid and triclosan have positive effects on improving DHA level of cells; (2) mutants from irradiation dosage of 120Gy yielded more DHA compared with cells from 40Gy, 80Gy treatment and wild type; (3) DHA contents of mutants pre-selected by inhibitors of enoyl-ACP reductase of Type II FAS pathway (isoniazid and triclosan)at 4°C, were significantly higher than that of wild type; (4) compared to the wild type, the DHA productivity and yield of a mutant (T-99) obtained from Aurantiochytrium sp. CGMCC 6208 by the proposed method increased by 50% from 0.18 to 0.27g/Lh and 30% from 21 to 27g/L, respectively. In conclusion, this study developed a feasible method to screen Aurantiochytrium sp. with high DHA yield by a combination of heavy-ion mutagenesis and mutant-preselection by FAS inhibitors and cold stress. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. NFκB in the Mechanism of Ammonia-Induced Astrocyte Swelling in Culture

    PubMed Central

    Sinke, A.P.; Jayakumar, A.R.; Panickar, K.S.; Moriyama, M.; Reddy, P.V.B.; Norenberg, M.D.

    2008-01-01

    Astrocyte swelling and brain edema are major neuropathological findings in the acute form of hepatic encephalopathy (fulminant hepatic failure, FHF), and substantial evidence supports the view that elevated brain ammonia level is an important etiological factor in this condition. Although the mechanism by which ammonia brings about astrocyte swelling remains to be determined, oxidative/nitrosative stress and mitogen-activated protein kinases (MAPKs) have been considered as important elements in this process. One factor known to be activated by both oxidative stress and MAPKs is nuclear factor κB (NFκB), a transcription factor that activates many genes, including inducible nitric oxide synthase (iNOS). Since the product of iNOS, nitric oxide (NO), is known to cause astrocyte swelling, we examined the potential involvement of NFκB in ammonia-induced astrocyte swelling. Western blot analysis of cultured astrocytes showed a significant increase in NFκB nuclear translocation (a measure of NFκB activation) from 12 h to 2 days after treatment with NH4Cl (5 mM). Cultures treated with antioxidants, including superoxide dismutase, catalase and vitamin E, as well as the MAPKs inhibitors SB239063 (an inhibitor of p38-MAPK), and SP600125 (an inhibitor of c-Jun N-terminal kinase, JNK) significantly diminished NFκB activation by ammonia, supporting a role of oxidative stress and MAPKs in NFκB activation. The activation of NFκB was associated with increased iNOS protein expression and NO generation, and these changes were blocked by BAY 11-7082, an inhibitor of NFκB. Additionally, ammonia-induced astrocyte swelling was inhibited by the NFκB inhibitors BAY 11-7082 and SN-50, thereby implicating NFκB in the mechanism of astrocyte swelling. Our studies indicate that cultured astrocytes exposed to ammonia display NFκB activation, which is likely a consequence of oxidative stress and activation of MAPKs. NFκB activation appears to contribute to the mechanism of ammonia

  10. The tumor promoter arsenite stimulates AP-1 activity by inhibiting a JNK phosphatase.

    PubMed Central

    Cavigelli, M; Li, W W; Lin, A; Su, B; Yoshioka, K; Karin, M

    1996-01-01

    Trivalent arsenic (As3+) is highly carcinogenic, but devoid of known mutagenic activity. Therefore, it is likely to act as a tumor promoter. To understand the molecular basis for the tumor-promoting activity of As3+, we examined its effect on transcription factor AP-1, whose activity is stimulated by several other tumor promoters. We found that As3+, but not As5+, which is toxic but not carcinogenic, is a potent stimulator of AP-1 transcriptional activity and an efficient inducer of c-fos and c-jun gene expression. Induction of c-jun and c-fos transcription by As3+ correlates with activation of Jun kinases (JNKs) and p38/Mpk2, which phosphorylate transcription factors that activate these immediate early genes. No effect on ERK activity was observed. As5+, on the other hand, had a negligible effect on JNK or p38/Mpk2 activity. Biochemical analysis and co-transfection experiments strongly suggest that the primary mechanism by which As3+ stimulates JNK activity involves the inhibition of a constitutive dual-specificity JNK phosphatase. This phosphatase activity appears to be responsible for maintaining low basal JNK activity in non-stimulated cells and its inhibition may lead to tumor promotion through induction of proto-oncogenes such as c-jun and c-fos, and stimulation of AP-1 activity. The same phosphatase may also regulate p38/Mpk2 activity. Images PMID:8947050

  11. Anti-proliferation of triple-negative breast cancer cells with physagulide P: ROS/JNK signaling pathway induces apoptosis and autophagic cell death

    PubMed Central

    Gao, Cai-Yun; Ma, Ting; Zhang, Hao; Zhou, Miao-Miao; Yang, Yan-Wei; Yang, Lei; Kong, Ling-Yi

    2017-01-01

    Physagulide P (PP), a new natural compound, was isolated from Physalis angulate L. in our laboratory. In this study, we demonstrated that PP potently suppressed cell proliferation by inducing G2/M phase arrest in MDA-MB-231 and MDA-MB-468 cells. Moreover, PP provoked apoptosis by decreasing the mitochondrial membrane potential and elevating the Bax/Bcl-2 protein expression ratio. The caspase inhibitor Z-VAD-FMK partly restore cell viability, suggesting that apoptosis plays as an important role in the anti-proliferative effect of PP. PP-treated cells also underwent autophagy, as evidenced by the formation of autophagosomes and the accumulation of LC3BII. Furthermore, the knockdown of LC3B reduced PP-induced cytotoxicity, indicating that autophagy played an anticancer effect. PP also induced the generation of reactive oxygen species (ROS) and resulted in c-Jun N-terminal kinases (JNK) activation. Accordingly, JNK siRNA significantly attenuated PP-triggered apoptosis and autophagy, and ROS scavengers almost completely reverse this apoptosis and autophagy. The ROS scavenger also blocked PP-induced G2/M phase arrest and the phosphorylation of JNK. Our results revealed that PP induced G2/M phase arrest, apoptosis and autophagy via the ROS/JNK signaling pathway in MDA-MB-231 and MDA-MB-468 cells. Therefore, PP is a promising candidate for the development of antitumor drugs for the treatment of triple-negative breast cancer. PMID:28969050

  12. A Low-Level Carbon Dioxide Laser Promotes Fibroblast Proliferation and Migration through Activation of Akt, ERK, and JNK

    PubMed Central

    Shingyochi, Yoshiaki; Kanazawa, Shigeyuki; Tajima, Satoshi; Tanaka, Rica; Mizuno, Hiroshi; Tobita, Morikuni

    2017-01-01

    Background Low-level laser therapy (LLLT) with various types of lasers promotes fibroblast proliferation and migration during the process of wound healing. Although LLLT with a carbon dioxide (CO2) laser was also reported to promote wound healing, the underlying mechanisms at the cellular level have not been previously described. Herein, we investigated the effect of LLLT with a CO2 laser on fibroblast proliferation and migration. Materials and Methods Cultured human dermal fibroblasts were prepared. MTS and cell migration assays were performed with fibroblasts after LLLT with a CO2 laser at various doses (0.1, 0.5, 1.0, 2.0, or 5.0 J/cm2) to observe the effects of LLLT with a CO2 laser on the proliferation and migration of fibroblasts. The non-irradiated group served as the control. Moreover, western blot analysis was performed using fibroblasts after LLLT with a CO2 laser to analyze changes in the activities of Akt, extracellular signal-regulated kinase (ERK), and Jun N-terminal kinase (JNK), which are signaling molecules associated with cell proliferation and migration. Finally, the MTS assay, a cell migration assay, and western blot analysis were performed using fibroblasts treated with inhibitors of Akt, ERK, or JNK before LLLT with a CO2 laser. Results In MTS and cell migration assays, fibroblast proliferation and migration were promoted after LLLT with a CO2 laser at 1.0 J/cm2. Western blot analysis revealed that Akt, ERK, and JNK activities were promoted in fibroblasts after LLLT with a CO2 laser at 1.0 J/cm2. Moreover, inhibition of Akt, ERK, or JNK significantly blocked fibroblast proliferation and migration. Conclusions These findings suggested that LLLT with a CO2 laser would accelerate wound healing by promoting the proliferation and migration of fibroblasts. Activation of Akt, ERK, and JNK was essential for CO2 laser-induced proliferation and migration of fibroblasts. PMID:28045948

  13. A Specific Peptide with Calcium-Binding Capacity from Defatted Schizochytrium sp. Protein Hydrolysates and the Molecular Properties.

    PubMed

    Cai, Xixi; Yang, Qian; Lin, Jiaping; Fu, Nanyan; Wang, Shaoyun

    2017-03-29

    Marine microorganisms have been proposed as a new kind of protein source. Efforts are needed in order to transform the protein-rich biological wastes left after lipid extraction into value-added bio-products. Thus, the utilization of protein recovered from defatted Schizochytrium sp. by-products presents an opportunity. A specific peptide Tyr-Leu (YL) with calcium-binding capacity was purified from defatted Schizochytrium sp. protein hydrolysates through gel filtration chromatography and RP-HPLC. The calcium-binding activity of YL reached 126.34 ± 3.40 μg/mg. The calcium-binding mechanism was investigated through ultraviolet, fluorescence and infrared spectroscopy. The results showed that calcium ions could form dative bonds with carboxyl oxygen atoms and amino nitrogen atoms as well as the nitrogen and oxygen atoms of amide bonds. YL-Ca exhibited excellent thermal stability and solubility, which was beneficial for its absorption and transport in the basic intestinal tract of the human body. Moreover, the cellular uptake of calcium in Caco-2 cells showed that YL-Ca could enhance calcium uptake efficiency and protect calcium ions against precipitation caused by dietary inhibitors such as tannic acid, oxalate, phytate and metal ions. The findings indicate that the by-product of Schizochytrium sp. is a promising source for making peptide-calcium bio-products as algae-based functional supplements for human beings.

  14. Calcineurin inhibitors recruit protein kinases JAK2 and JNK, TLR signaling and the UPR to activate NF-κB-mediated inflammatory responses in kidney tubular cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    González-Guerrero, Cristian, E-mail: cristian.gonzalez@fjd.es; Ocaña-Salceda, Carlos, E-mail: carlos.ocana@fjd.es; Berzal, Sergio, E-mail: sberzal@fjd.es

    The calcineurin inhibitors (CNIs) cyclosporine (CsA) and tacrolimus are key drugs in current immunosuppressive regimes for solid organ transplantation. However, they are nephrotoxic and promote death and profibrotic responses in tubular cells. Moreover, renal inflammation is observed in CNI nephrotoxicity but the mechanisms are poorly understood. We have now studied molecular pathways leading to inflammation elicited by the CNIs in cultured and kidney tubular cells. Both CsA and tacrolimus elicited a proinflammatory response in tubular cells as evidenced by a transcriptomics approach. Transcriptomics also suggested several potential pathways leading to expression of proinflammatory genes. Validation and functional studies disclosed thatmore » in tubular cells, CNIs activated protein kinases such as the JAK2/STAT3 and TAK1/JNK/AP-1 pathways, TLR4/Myd88/IRAK signaling and the Unfolded Protein Response (UPR) to promote NF-κB activation and proinflammatory gene expression. CNIs also activated an Nrf2/HO-1-dependent compensatory response and the Nrf2 activator sulforaphane inhibited JAK2 and JNK activation and inflammation. A murine model of CsA nephrotoxicity corroborated activation of the proinflammatory pathways identified in cell cultures. Human CNIs nephrotoxicity was also associated with NF-κB, STAT3 and IRE1α activation. In conclusion, CNIs recruit several intracellular pathways leading to previously non-described proinflammatory actions in renal tubular cells. Identification of these pathways provides novel clues for therapeutic intervention to limit CNIs nephrotoxicity. - Highlights: • Molecular mechanisms modulating CNI renal inflammation were investigated. • Kinases, immune receptors and ER stress mediate the inflammatory response to CNIs. • Several intracellular pathways activate NF-κB in CNIs-treated tubular cells. • A NF-κB-dependent cytokine profile characterizes CNIs-induced inflammation. • CNI nephrotoxicity was associated to

  15. Spatiotemporal regulation of ERK2 by dual specificity phosphatases.

    PubMed

    Caunt, Christopher J; Armstrong, Stephen P; Rivers, Caroline A; Norman, Michael R; McArdle, Craig A

    2008-09-26

    Although many stimuli activate extracellular signal-regulated kinases 1 and 2 (ERK1/2), the kinetics and compartmentalization of ERK1/2 signals are stimulus-dependent and dictate physiological consequences. ERKs can be inactivated by dual specificity phosphatases (DUSPs), notably the MAPK phosphatases (MKPs) and atypical DUSPs, that can both dephosphorylate and scaffold ERK1/2. Using a cell imaging model (based on knockdown of endogenous ERKs and add-back of wild-type or mutated ERK2-GFP reporters), we explored possible effects of DUSPs on responses to transient or sustained ERK2 activators (epidermal growth factor and phorbol 12,13-dibutyrate, respectively). For both stimuli, a D319N mutation (which impairs DUSP binding) increased ERK2 activity and reduced nuclear accumulation. These stimuli also increased mRNA levels for eight DUSPs. In a short inhibitory RNA screen, 12 of 16 DUSPs influenced ERK2 responses. These effects were evident among nuclear inducible MKP, cytoplasmic ERK MKP, JNK/p38 MKP, and atypical DUSP subtypes and, with the exception of the nuclear inducible MKPs, were paralleled by corresponding changes in Egr-1 luciferase activation. Simultaneous removal of all JNK/p38 MKPs or nuclear inducible MKPs revealed them as positive and negative regulators of ERK2 signaling, respectively. The effects of JNK/p38 MKP short inhibitory RNAs were not dependent on protein neosynthesis but were reversed in the presence of JNK and p38 kinase inhibitors, indicating DUSP-mediated cross-talk between MAPK pathways. Overall, our data reveal that a large number of DUSPs influence ERK2 signaling. Together with the known tissue-specific expression of DUSPs and the importance of ERK1/2 in cell regulation, our data support the potential value of DUSPs as targets for drug therapy.

  16. JNK Signaling: Regulation and Functions Based on Complex Protein-Protein Partnerships

    PubMed Central

    Zeke, András; Misheva, Mariya

    2016-01-01

    SUMMARY The c-Jun N-terminal kinases (JNKs), as members of the mitogen-activated protein kinase (MAPK) family, mediate eukaryotic cell responses to a wide range of abiotic and biotic stress insults. JNKs also regulate important physiological processes, including neuronal functions, immunological actions, and embryonic development, via their impact on gene expression, cytoskeletal protein dynamics, and cell death/survival pathways. Although the JNK pathway has been under study for >20 years, its complexity is still perplexing, with multiple protein partners of JNKs underlying the diversity of actions. Here we review the current knowledge of JNK structure and isoforms as well as the partnerships of JNKs with a range of intracellular proteins. Many of these proteins are direct substrates of the JNKs. We analyzed almost 100 of these target proteins in detail within a framework of their classification based on their regulation by JNKs. Examples of these JNK substrates include a diverse assortment of nuclear transcription factors (Jun, ATF2, Myc, Elk1), cytoplasmic proteins involved in cytoskeleton regulation (DCX, Tau, WDR62) or vesicular transport (JIP1, JIP3), cell membrane receptors (BMPR2), and mitochondrial proteins (Mcl1, Bim). In addition, because upstream signaling components impact JNK activity, we critically assessed the involvement of signaling scaffolds and the roles of feedback mechanisms in the JNK pathway. Despite a clarification of many regulatory events in JNK-dependent signaling during the past decade, many other structural and mechanistic insights are just beginning to be revealed. These advances open new opportunities to understand the role of JNK signaling in diverse physiological and pathophysiological states. PMID:27466283

  17. JNK Signaling: Regulation and Functions Based on Complex Protein-Protein Partnerships.

    PubMed

    Zeke, András; Misheva, Mariya; Reményi, Attila; Bogoyevitch, Marie A

    2016-09-01

    The c-Jun N-terminal kinases (JNKs), as members of the mitogen-activated protein kinase (MAPK) family, mediate eukaryotic cell responses to a wide range of abiotic and biotic stress insults. JNKs also regulate important physiological processes, including neuronal functions, immunological actions, and embryonic development, via their impact on gene expression, cytoskeletal protein dynamics, and cell death/survival pathways. Although the JNK pathway has been under study for >20 years, its complexity is still perplexing, with multiple protein partners of JNKs underlying the diversity of actions. Here we review the current knowledge of JNK structure and isoforms as well as the partnerships of JNKs with a range of intracellular proteins. Many of these proteins are direct substrates of the JNKs. We analyzed almost 100 of these target proteins in detail within a framework of their classification based on their regulation by JNKs. Examples of these JNK substrates include a diverse assortment of nuclear transcription factors (Jun, ATF2, Myc, Elk1), cytoplasmic proteins involved in cytoskeleton regulation (DCX, Tau, WDR62) or vesicular transport (JIP1, JIP3), cell membrane receptors (BMPR2), and mitochondrial proteins (Mcl1, Bim). In addition, because upstream signaling components impact JNK activity, we critically assessed the involvement of signaling scaffolds and the roles of feedback mechanisms in the JNK pathway. Despite a clarification of many regulatory events in JNK-dependent signaling during the past decade, many other structural and mechanistic insights are just beginning to be revealed. These advances open new opportunities to understand the role of JNK signaling in diverse physiological and pathophysiological states. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  18. Different signal pathways regulate IL-1β-induced mature and primary miRNA-146a expression in human alveolar epithelial cells.

    PubMed

    Jiang, Xiaoying

    2014-09-01

    It was known that IL-1β-induced rapid expression of miR-146a, which regulated the secretion of inflammatory chemokines in human A549 alveolar epithelial cells. However, little is known about the level of primary miR-146a and the downstream biogenesis of miR-146a in A549 cells. We examined the levels of primary miR-146a and mature miR-146a in A549 cells following treatment with pharmacological inhibitors of IKK-2 (TPCA-1), MEK-1/2 (PD098059), JNK-1/2 (SP600125), p38 MAPK (SB 203580) and PI-3k (LY294002). Our studies showed that exposure to PD98059, TPCA-1 and LY294002 resulted in a dose-dependent reduction in the expression of mature miR-146a while the primary miR-146a expression was not changed by any inhibitor. Western blot showed that IL-1β induced an increase of TRBP at 30 min, following by an extended expression at 24 h compared to the non-IL-1β controls in A549 cells. In conclusion, our studies indicated that miR-146a expression in alveolar epithelial cells was regulated at the post-transcriptional level via a MEK-1/2 and IKK2 pathway, and also for the first time via PI-3k pathway. The longer expression of TRBP following stimulation with IL-1β suggests that TRBP might play a role in the process of regulating the processing of primary miR-146a to mature miR-146a in human alveolar epithelial cells.

  19. A RNA Interference Screen Identifies the Protein Phosphatase 2A Subunit PR55γ as a Stress-Sensitive Inhibitor of c-SRC

    PubMed Central

    Eichhorn, Pieter J. A; Creyghton, Menno P; Wilhelmsen, Kevin; van Dam, Hans; Bernards, René

    2007-01-01

    Protein Phosphatase type 2A (PP2A) represents a family of holoenzyme complexes with diverse biological activities. Specific holoenzyme complexes are thought to be deregulated during oncogenic transformation and oncogene-induced signaling. Since most studies on the role of this phosphatase family have relied on the use of generic PP2A inhibitors, the contribution of individual PP2A holoenzyme complexes in PP2A-controlled signaling pathways is largely unclear. To gain insight into this, we have constructed a set of shRNA vectors targeting the individual PP2A regulatory subunits for suppression by RNA interference. Here, we identify PR55γ and PR55δ as inhibitors of c-Jun NH2-terminal kinase (JNK) activation by UV irradiation. We show that PR55γ binds c-SRC and modulates the phosphorylation of serine 12 of c-SRC, a residue we demonstrate to be required for JNK activation by c-SRC. We also find that the physical interaction between PR55γ and c-SRC is sensitive to UV irradiation. Our data reveal a novel mechanism of c-SRC regulation whereby in response to stress c-SRC activity is regulated, at least in part, through loss of the interaction with its inhibitor, PR55γ. PMID:18069897

  20. Blocking autophagy enhances the apoptotic effect of 18β-glycyrrhetinic acid on human sarcoma cells via endoplasmic reticulum stress and JNK activation.

    PubMed

    Shen, Shuying; Zhou, Menglu; Huang, Kangmao; Wu, Yizheng; Ma, Yan; Wang, Jiying; Ma, Jianjun; Fan, Shunwu

    2017-09-21

    Sarcoma, a rare form of cancer, is unlike the much more common carcinomas as it occurs in a distinct type of tissue. The potent antitumor effects of 18β-glycyrrhetinic acid (GA), a novel naturally derived agent, have been demonstrated in various cancers. However, the effect of GA on human sarcoma, and the underlying mechanisms, remain to be elucidated. In the current study, we show that GA inhibits sarcoma cell proliferation by inducing G0/G1-phase arrest. Exposure to GA resulted in the activation of caspase-3, -8, and -9, indicating that GA induced apoptosis through both extrinsic and intrinsic pathways. In addition, the autophagy pathway, characterized by the conversion of LC3-I to LC3- II, was activated, resulting in increased Beclin-1 protein levels, decreased p62 expression, and stimulation of autophagic flux. The present findings showed that GA stimulated autophagy by inducing endoplasmic reticulum (ER) stress via the IRE1-JNK pathway. Our data supported the prosurvival role of GA-induced autophagy when the autophagy pathway was blocked with specific chemical inhibitors. Finally, GA markedly reduced sarcoma growth, with little organ-related toxicity, in vivo. The present results suggest that the combination of GA with a specific autophagy inhibitor represents a promising therapeutic approach for the treatment of sarcoma.

  1. Lysophosphatidylcholine up-regulates human endothelial nitric oxide synthase gene transactivity by c-Jun N-terminal kinase signalling pathway

    PubMed Central

    Xing, Feiyue; Liu, Jing; Mo, Yongyan; Liu, Zhifeng; Qin, Qinghe; Wang, Jingzhen; Fan, Zhenhua; Long, Yutian; Liu, Na; Zhao, Kesen; Jiang, Yong

    2009-01-01

    Human endothelial nitric oxide synthase (eNOS) plays a pivotal role in maintaining blood pressure homeostasis and vascular integrity. It has recently been reported that mitogen-activated protein kinases (MAPKs) are intimately implicated in expression of eNOS. However detailed mechanism mediated by them remains to be clarified. In this study, eNOS gene transactivity in human umbilical vein endothelial cells was up-regulated by stimulation of lysophosphatidylcholine (LPC). The stimulation of LPC highly activated both extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK), with differences in the dynamic processes of activation between them. Unexpectedly, p38 MAPK could not be activated by the stimulation of LPC. The activation of JNK signalling pathway by overexpression of JNK or its upstream kinase active mutant up-regulated the transactivity of eNOS significantly, but the activation of p38 signalling pathway down-regulated it largely. The inhibition of either ERK1/2 or JNK signalling pathway by kinase-selective inhibitors could markedly block the induction of the transactivity by LPC. It was observed by electrophoretic mobility shift assay that LPC stimulated both SP1 and AP1 DNA binding activity to go up. Additionally using decoy oligonucleotides proved that SP1 was necessary for maintaining the basal or stimulated transactivity, whereas AP1 contributed mainly to the increase of the stimulated transactivity. These findings indicate that the up-regulation of the eNOS gene transactivity by LPC involves the enhancement of SP1 transcription factor by the activation of JNK and ERK1/2 signalling pathways and AP1 transcription factor by the activation of JNK signalling pathway. PMID:18624763

  2. PDE5 Inhibitors Enhance Celecoxib Killing in Multiple Tumor Types

    PubMed Central

    BOOTH, LAURENCE; ROBERTS, JANE L.; CRUICKSHANKS, NICHOLA; TAVALLAI, SEYEDMEHRAD; WEBB, TIMOTHY; SAMUEL, PETER; CONLEY, ADAM; BINION, BRITTANY; YOUNG, HAROLD F.; POKLEPOVIC, ANDREW; SPIEGEL, SARAH; DENT, PAUL

    2015-01-01

    The present studies determined whether clinically relevant phosphodiesterase 5 (PDE5) inhibitors interacted with a clinically relevant NSAID, celecoxib, to kill tumor cells. Celecoxib and PDE5 inhibitors interacted in a greater than additive fashion to kill multiple tumor cell types. Celecoxib and sildenafil killed ex vivo primary human glioma cells as well as their associated activated microglia. Knock down of PDE5 recapitulated the effects of PDE5 inhibitor treatment; the nitric oxide synthase inhibitor L-NAME suppressed drug combination toxicity. The effects of celecoxib were COX2 independent. Over-expression of c-FLIP-s or knock down of CD95/FADD significantly reduced killing by the drug combination. CD95 activation was dependent on nitric oxide and ceramide signaling. CD95 signaling activated the JNK pathway and inhibition of JNK suppressed cell killing. The drug combination inactivated mTOR and increased the levels of autophagy and knock down of Beclin1 or ATG5 strongly suppressed killing by the drug combination. The drug combination caused an ER stress response; knock down of IRE1α/XBP1 enhanced killing whereas knock down of eIF2α/ATF4/CHOP suppressed killing. Sildenafil and celecoxib treatment suppressed the growth of mammary tumors in vivo. Collectively our data demonstrate that clinically achievable concentrations of celecoxib and sildenafil have the potential to be a new therapeutic approach for cancer. PMID:25303541

  3. Functional cooperation between HIF-1α and c-Jun in mediating primary and acquired resistance to gefitinib in NSCLC cells with activating mutation of EGFR.

    PubMed

    Meng, Shuyan; Wang, Guorui; Lu, Yang; Fan, Zhen

    2018-07-01

    Hypoxia-inducible factor 1 (HIF-1) and activator protein 1 (AP-1) are important transcription factors regulating expression of genes involved in cell survival. HIF-1α and c-Jun are key components of HIF-1 and AP-1, respectively, and are regulated by epidermal growth factor receptor (EGFR)-mediated cell signaling and tumor microenvironmental cues. The roles of HIF-1α and c-Jun in development of resistance to EGFR tyrosine kinase inhibitor (TKI) in non-small cell lung cancer (NSCLC) with activating mutation of EGFR have not been explored. In this study, we investigated the roles of HIF-1α and c-Jun in mediating primary and acquired resistance to gefitinib in NSCLC cells with activating mutation of EGFR. Changes in HIF-1α protein and in total and phosphorylated c-Jun levels in relation to changes in total and phosphorylated EGFR levels before and after gefitinib treatment were measured using Western blot analysis in NSCLC cells sensitive or resistant to gefitinib. The impact of overexpression of a constitutively expressed HIF-1α (HIF-1α/ΔODD) or a constitutively active c-Jun upstream regulator (SEK1 S220E/T224D mutant) on cell response to gefitinib was also examined. The effect of pharmacological inhibition of SEK1-JNK-c-Jun pathway on cell response to gefitinib was evaluated. Downregulation of HIF-1α and total and phosphorylated c-Jun levels correlated with cell inhibitory response to gefitinib better than decrease in phosphorylated EGFR did in NSCLC cells with intrinsic or acquired resistance to gefitinib. Overexpression of HIF-1α/ΔODD or SEK1 S220E/T224D mutant conferred resistance to gefitinib. There exists a positive feed-forward regulation loop between HIF-1 and c-Jun. The JNK inhibitor SP600125 sensitized gefitinib-resistant NSCLC cells to gefitinib. HIF-1α and c-Jun functionally cooperate in development of resistance to gefitinib in NSCLC cells. The translational value of inhibiting HIF-1α/c-Jun cooperation in overcoming resistance to EGFR TKI

  4. A family-specific use of the Measure of Processes of Care for Service Providers (MPOC-SP).

    PubMed

    Siebes, R C; Nijhuis, B J G; Boonstra, A M; Ketelaar, M; Wijnroks, L; Reinders-Messelink, H A; Postema, K; Vermeer, A

    2008-03-01

    To examine the validity and utility of the Dutch Measure of Processes of Care for Service Providers (MPOC-SP) as a family-specific measure. A validation study. Five paediatric rehabilitation settings in the Netherlands. The MPOC-SP was utilized in a general (reflecting on services provided for all clients and clients' families) and family-specific way (filled out in reference to a particular child and his or her family). Professionals providing rehabilitation and educational services to children with cerebral palsy. For construct validity, Pearson's product-moment correlation coefficients (r ) between the scales were calculated. The ability of service providers to discriminate between general and family-specific ratings was examined by exploration of absolute difference scores. One hundred and sixteen service professionals filled out 240 family-specific MPOC-SPs. In addition, a subgroup of 81 professionals filled out a general MPOC-SP. For each professional, family-specific and general scores were paired, resulting in 151 general-family-specific MPOC-SP pairs. The construct validity analyses confirmed the scale structure: 21 items (77.8%) loaded highest in the original MPOC-SP factors, and all items correlated best and significantly with their own scale score (r 0.565 to 0.897; P<0.001). Intercorrelations between the scales ranged from r = 0.159 to r = 0.522. In total, 94.4% of the mean absolute difference scores between general and family-specific scale scores were larger than the expected difference. Service providers were able to discriminate between general and family-specific MPOC-SP item ratings. The family-specific MPOC-SP is a valid measure that can be used for individual evaluation of family-centred services and can be the impetus for family-related quality improvement.

  5. In Silico Analysis of the Potential of the Active Compounds Fucoidan and Alginate Derived from Sargassum Sp. as Inhibitors of COX-1 and COX-2.

    PubMed

    Dewi, Lestari

    2016-06-01

    The enzyme cyclooxygenase (COX) is an enzyme that catalyzes the formation of one of the mediators of inflammation, the prostaglandins. Inhibition of COX allegedly can improve inflammation-induced pathological conditions. The purpose of the present study was to evaluate the potential of Sargassum sp. components, Fucoidan and alginate, as COX inhibitors. The study was conducted by means of a computational (in silico) method. It was performed in two main stages, the docking between COX-1 and COX-2 with Fucoidan, alginate and aspirin (for comparison) and the analysis of the amount of interactions formed and the residues directly involved in the process of interaction. Our results showed that both Fucoidan and alginate had an excellent potential as inhibitors of COX-1 and COX-2. Fucoidan had a better potential as an inhibitor of COX than alginate. COX inhibition was expected to provide a more favorable effect on inflammation-related pathological conditions. The active compounds Fucoidan and alginate derived from Sargassum sp. were suspected to possess a good potential as inhibitors of COX-1 and COX-2.

  6. Chemical Characterization and Antitumor Activities of Polysaccharide Extracted from Ganoderma lucidum

    PubMed Central

    Liang, Zengenni; Yi, Youjin; Guo, Yutong; Wang, Rencai; Hu, Qiulong; Xiong, Xingyao

    2014-01-01

    Ganoderma lucidum polysaccharide (GLP) is a biologically active substance reported to possess anti-tumor ability. Nonetheless, the mechanisms of GLP-stimulated apoptosis are still unclear. This study aims to determine the inhibitory and apoptosis-inducing effects of GLP on HCT-116 cells. We found that GLP reduced cell viability on HCT-116 cells in a time- and dose-dependent manner, which in turn, induced cell apoptosis. The observed apoptosis was characterized by morphological changes, DNA fragmentation, mitochondrial membrane potential decrease, S phase population increase, and caspase-3 and -9 activation. Furthermore, inhibition of c-Jun N-terminal kinase (JNK) by SP600125 led to a dramatic decrease of the GLP-induced apoptosis. Western blot analysis unveiled that GLP up-regulated the expression of Bax/Bcl-2, caspase-3 and poly (ADP-ribose) polymerase (PARP). These results demonstrate that apoptosis stimulated by GLP in human colorectal cancer cells is associated with activation of mitochondrial and mitogen-activated protein kinase (MAPK) pathways. PMID:24857920

  7. Design and synthesis of the first generation of novel potent, selective, and in vivo active (benzothiazol-2-yl)acetonitrile inhibitors of the c-Jun N-terminal kinase.

    PubMed

    Gaillard, Pascale; Jeanclaude-Etter, Isabelle; Ardissone, Vittoria; Arkinstall, Steve; Cambet, Yves; Camps, Montserrat; Chabert, Christian; Church, Dennis; Cirillo, Rocco; Gretener, Denise; Halazy, Serge; Nichols, Anthony; Szyndralewiez, Cedric; Vitte, Pierre-Alain; Gotteland, Jean-Pierre

    2005-07-14

    Several lines of evidence support the hypothesis that c-Jun N-terminal kinase (JNKs) plays a critical role in a wide range of diseases including cell death (apoptosis)-related disorders (neurodegenerative diseases, brain, heart, and renal ischemia, epilepsy) and inflammatory disorders (multiple sclerosis, rheumatoid arthritis, inflammatory bowel diseases). Screening of our internal compound collection for inhibitors of JNK3 led to the identification of (benzothiazol-2-yl)acetonitrile derivatives as potent and selective JNK1, -2, -3 inhibitors. Starting from initial hit 1 (AS007149), the chemistry and initial structure-activity relationship (SAR) of this novel and unique kinase inhibitor template were explored. Investigation of the SAR rapidly revealed that the benzothiazol-2-ylacetonitrile pyrimidine core was crucial to retain a good level of potency on rat JNK3. Therefore, compound 6 was further optimized by exploring a number of distal combinations in place of the chlorine atom. This led to the observation that the presence of an aromatic group, two carbons away from the aminopyrimidine moiety and bearing substituents conferring hydrogen bond acceptor (HBA) properties, could improve the potency. Further improvements to the biological and biopharmaceutical profile of the most promising compounds were performed, resulting in the discovery of compound 59 (AS601245). The in vitro and in vivo anti-inflammatory potential of this new JNK inhibitor was investigated and found to demonstrate efficacy per oral route in an experimental model of rheumatoid arthritis (RA).

  8. New small-molecule inhibitor class targeting human immunodeficiency virus type 1 virion maturation.

    PubMed

    Blair, Wade S; Cao, Joan; Fok-Seang, Juin; Griffin, Paul; Isaacson, Jason; Jackson, R Lynn; Murray, Edward; Patick, Amy K; Peng, Qinghai; Perros, Manos; Pickford, Chris; Wu, Hua; Butler, Scott L

    2009-12-01

    A new small-molecule inhibitor class that targets virion maturation was identified from a human immunodeficiency virus type 1 (HIV-1) antiviral screen. PF-46396, a representative molecule, exhibits antiviral activity against HIV-1 laboratory strains and clinical isolates in T-cell lines and peripheral blood mononuclear cells (PBMCs). PF-46396 specifically inhibits the processing of capsid (CA)/spacer peptide 1 (SP1) (p25), resulting in the accumulation of CA/SP1 (p25) precursor proteins and blocked maturation of the viral core particle. Viral variants resistant to PF-46396 contain a single amino acid substitution in HIV-1 CA sequences (CAI201V), distal to the CA/SP1 cleavage site in the primary structure, which we demonstrate is sufficient to confer significant resistance to PF-46396 and 3-O-(3',3'-dimethylsuccinyl) betulinic acid (DSB), a previously described maturation inhibitor. Conversely, a single amino substitution in SP1 (SP1A1V), which was previously associated with DSB in vitro resistance, was sufficient to confer resistance to DSB and PF-46396. Further, the CAI201V substitution restored CA/SP1 processing in HIV-1-infected cells treated with PF-46396 or DSB. Our results demonstrate that PF-46396 acts through a mechanism that is similar to DSB to inhibit the maturation of HIV-1 virions. To our knowledge, PF-46396 represents the first small-molecule HIV-1 maturation inhibitor that is distinct in chemical class from betulinic acid-derived maturation inhibitors (e.g., DSB), demonstrating that molecules of diverse chemical classes can inhibit this mechanism.

  9. Inhibitors of BRD4 Protein from a Marine-Derived Fungus Alternaria sp. NH-F6

    PubMed Central

    Ding, Hui; Zhang, Dashan; Zhou, Biao; Ma, Zhongjun

    2017-01-01

    Bromodomains (BRD) are readers of the epigenetic code that regulate gene transcription through their recognition of acetyl-lysine modified histone tails. Recently, bromodomain-containing proteins such as BRD4 have been demonstrated to be druggable through the discovery of potent inhibitors. These protein–protein interaction inhibitors have the potential to modulate multiple diseases by their profound anti-inflammatory and antiproliferative effects. In order to explore new BRD4 inhibitors as well as lead compounds for the development of new drugs, the secondary metabolites of Alternaria sp. NH-F6, a fungus isolated from deep-sea sediment samples, were analyzed systematically. Five new compounds including two new perylenequinones (1–2), one new alternaric acid (3), 2-(N-vinylacetamide)-4-hydroxymethyl-3-ene-butyrolactone (4), one new cerebroside (5), together with 19 known compounds (6–24) were isolated from the ethyl acetate extracts of this strain. Their structures were elucidated using nuclear magnetic resonance (NMR) and high resolution electrospray ionization mass spectrometry (HR-ESI-MS) analyses. Finally, all these compounds were evaluated for their inhibitory activity against BRD4 protein, and compound 2 exhibited a potent inhibition rate of 88.1% at a concentration of 10 µM. This research provides a new BRD4 inhibitor which may possess potential antitumoral, antiviral, or anti-inflammatory pharmaceutical values. PMID:28300771

  10. CARFILZOMIB INTERACTS SYNERGISTICALY WITH HISTONE DEACETYLASE INHIBITORS IN MANTLE CELL LYMPHOMA CELLS IN VITRO AND IN VIVO

    PubMed Central

    Dasmahapatra, Girija; Lembersky, Dmitry; Son, Minkyeong P.; Attkisson, Elisa; Dent, Paul; Fisher, Richard. I.; Friedberg, Jonathan W.; Grant, Steven

    2011-01-01

    Interactions between the proteasome inhibitor carfilzomib and the HDAC inhibitors vorinostat and SNDX-275 were examined in mantle cell lymphoma (MCL) cells in vitro and in vivo. Co-administration of very low, marginally toxic carfilzomib concentrations (e.g., 3–4 nM) with minimally lethal vorinostat or SNDX-275 concentrations induced sharp increases in mitochondrial injury and apoptosis in multiple MCL cell lines and primary MCL cells. Enhanced lethalitly was associated with JNK1/2 activation, increased DNA damage (induction of λH2A.X), and ERK1/2 and AKT1/2 inactivation. Co-administration of carfilzomib and HDACIs induced a marked increase in ROS generation, and G2M arrest. Significantly, the free radical scavenger TBAP blocked carfilzomib/HDACI-mediated ROS generation, λH2A.X formation, JNK1/2 activation, and lethality. Genetic (shRNA) knock down of JNK1/2 significantly attenuated carfilzomib/HDACI-induced apoptosis, but did not prevent ROS generation or DNA damage. Carfilzomib/HDACI regimens were also active against bortezomib-resistant MCL cells. Finally, carfilzomib/vorinostat co-administrationo resulted in a pronounced reduction in tumor growth compared to single agent treatment in a MCL xenograft model associated with enhanced apoptosis, λH2A.X formation, and JNK activation. Collectively, these findings suggest that carfilzomib/HDACI regimens warrants attention in MCL. PMID:21750224

  11. EI-2128-1, a novel interleukin-1beta converting enzyme inhibitor produced by Penicillium sp. E-2128.

    PubMed

    Koizumi, Fumito; Agatsuma, Tsutomu; Ando, Katsuhiko; Kondo, Hidemasa; Saitoh, Yutaka; Matsuda, Yuzuru; Nakanishi, Satoshi

    2003-11-01

    EI-2128-1, a novel interleukin-1beta converting enzyme (ICE) inhibitor, was isolated from the culture broths of Penicillium sp. E-2128. EI-2128-1 selectively inhibited human recombinant ICE activity with IC50 value of 0.59 microM, without inhibiting elastase and cathepsin B. EI-2128-1 also inhibited mature interleukin-1beta secretion from THP-1 cells induced by LPS with IC50 value of 0.28 microM.

  12. The novel gluconeogenesis inhibitors FR225659 and related compounds that originate from Helicomyces sp. No. 19353. I. Taxonomy, fermentation, isolation and physico-chemical properties.

    PubMed

    Ohtsu, Yoshihiro; Sasamura, Hiromi; Tsurumi, Yasuhisa; Yoshimura, Seiji; Takase, Shigehiro; Hashimoto, Michizane; Shibata, Toshihiro; Hino, Motohiro; Fujii, Takashi

    2003-08-01

    FR225659 and four related compounds are novel gluconeogenesis inhibitors that consist of a novel acyl-group and three abnormal amino acids. They were isolated from the culture broth of Helicomyces sp. No. 19353 and can be purified by absorptive resin and reverse-phase column chromatography. They are potent inhibitors of gluconeogenesis in primary cultured rat hepatocytes and thus may be useful as anti-diabetic agents.

  13. Transforming growth factor-β1 induces expression of human coagulation factor XII via Smad3 and JNK signaling pathways in human lung fibroblasts.

    PubMed

    Jablonska, Ewa; Markart, Philipp; Zakrzewicz, Dariusz; Preissner, Klaus T; Wygrecka, Malgorzata

    2010-04-09

    Coagulation factor XII (FXII) is a liver-derived serine protease involved in fibrinolysis, coagulation, and inflammation. The regulation of FXII expression is largely unknown. Transforming growth factor-beta1 (TGF-beta1) is a multifunctional cytokine that has been linked to several pathological processes, including tissue fibrosis by modulating procoagulant and fibrinolytic activities. This study investigated whether TGF-beta1 may regulate FXII expression in human lung fibroblasts. Treatment of human lung fibroblasts with TGF-beta1 resulted in a time-dependent increase in FXII production, activation of p44/42, p38, JNK, and Akt, and phosphorylation and translocation into the nucleus of Smad3. However, TGF-beta1-induced FXII expression was repressed only by the JNK inhibitor and JNK and Smad3 antisense oligonucleotides but not by MEK, p38, or phosphoinositide 3-kinase blockers. JNK inhibition had no effect on TGF-beta1-induced Smad3 phosphorylation, association with Smad4, and its translocation into the nucleus but strongly suppressed Smad3-DNA complex formation. FXII promoter analysis revealed that the -299/+1 region was sufficient for TGF-beta1 to induce FXII expression. Sequence analysis of this region detected a potential Smad-binding element at position -272/-269 (SBE-(-272/-269)). Chromatin immunoprecipitation and streptavidin pulldown assays demonstrated TGF-beta1-dependent Smad3 binding to SBE-(-272/-269). Mutation or deletion of SBE-(-272/-269) substantially reduced TGF-beta1-mediated activation of the FXII promoter. Clinical relevance was demonstrated by elevated FXII levels and its co-localization with fibroblasts in the lungs of patients with acute respiratory distress syndrome. Our results show that JNK/Smad3 pathway plays a critical role in TGF-beta1-induced FXII expression in human lung fibroblasts and implicate its possible involvement in pathological conditions characterized by elevated TGF-beta1 levels.

  14. A Protein Scaffold Coordinates SRC-Mediated JNK Activation in Response to Metabolic Stress.

    PubMed

    Kant, Shashi; Standen, Claire L; Morel, Caroline; Jung, Dae Young; Kim, Jason K; Swat, Wojciech; Flavell, Richard A; Davis, Roger J

    2017-09-19

    Obesity is a major risk factor for the development of metabolic syndrome and type 2 diabetes. How obesity contributes to metabolic syndrome is unclear. Free fatty acid (FFA) activation of a non-receptor tyrosine kinase (SRC)-dependent cJun NH 2 -terminal kinase (JNK) signaling pathway is implicated in this process. However, the mechanism that mediates SRC-dependent JNK activation is unclear. Here, we identify a role for the scaffold protein JIP1 in SRC-dependent JNK activation. SRC phosphorylation of JIP1 creates phosphotyrosine interaction motifs that bind the SH2 domains of SRC and the guanine nucleotide exchange factor VAV. These interactions are required for SRC-induced activation of VAV and the subsequent engagement of a JIP1-tethered JNK signaling module. The JIP1 scaffold protein, therefore, plays a dual role in FFA signaling by coordinating upstream SRC functions together with downstream effector signaling by the JNK pathway. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  15. Endothelial Dysfunction in Human Diabetes is mediated by Wnt5a-JNK Signaling

    PubMed Central

    Bretón-Romero, Rosa; Feng, Bihua; Holbrook, Monika; Farb, Melissa G.; Fetterman, Jessica L.; Linder, Erika A.; Berk, Brittany D.; Masaki, Nobuyuki; Weisbrod, Robert M.; Inagaki, Elica; Gokce, Noyan; Fuster, Jose J.; Walsh, Kenneth; Hamburg, Naomi M.

    2016-01-01

    Objectives Endothelial dysfunction is linked to insulin resistance, inflammatory activation and increased cardiovascular risk in diabetes mellitus; however the mechanisms remain incompletely understood. Recent studies have identified pro-inflammatory signaling of Wnt5a through JNK as a regulator of metabolic dysfunction with potential relevance to vascular function. We sought to gain evidence that increased activation of Wnt5a-JNK signaling contributes to impaired endothelial function in patients with diabetes mellitus. Approach We measured flow-mediated dilation of the brachial artery and characterized freshly isolated endothelial cells by protein expression, eNOS activation, and nitric oxide production in from 85 subjects with Type 2 diabetes mellitus (n=42) and age- and sex-matched non-diabetic controls (n=43) and in human aortic endothelial cells treated with Wnt5a. Results Endothelial cells from patients with diabetes displayed 1.3-fold higher Wnt5a levels (P=0.01) along with 1.4-fold higher JNK activation (P<0.01) without a difference in total JNK levels. Higher JNK activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction (r=0.53, P=0.02). Inhibition of Wnt5a and JNK signaling restored insulin and A23187-mediated eNOS activation and improved nitric oxide production in endothelial cells from patients with diabetes. In endothelial cells from non-diabetic controls, rWnt5a treatment inhibited eNOS activation replicating the diabetic endothelial phenotype. In HAECs, Wnt5a-induced impairment of eNOS activation and nitric oxide production was reversed by Wnt5a and JNK inhibition. Conclusions Our findings demonstrate that non-canonical Wnt5a signaling and JNK activity contributes to vascular insulin resistance and endothelial dysfunction and may represent a novel therapeutic opportunity to protect the vasculature in patients with diabetes. PMID:26800561

  16. Endothelial Dysfunction in Human Diabetes Is Mediated by Wnt5a-JNK Signaling.

    PubMed

    Bretón-Romero, Rosa; Feng, Bihua; Holbrook, Monika; Farb, Melissa G; Fetterman, Jessica L; Linder, Erika A; Berk, Brittany D; Masaki, Nobuyuki; Weisbrod, Robert M; Inagaki, Elica; Gokce, Noyan; Fuster, Jose J; Walsh, Kenneth; Hamburg, Naomi M

    2016-03-01

    Endothelial dysfunction is linked to insulin resistance, inflammatory activation, and increased cardiovascular risk in diabetes mellitus; however, the mechanisms remain incompletely understood. Recent studies have identified proinflammatory signaling of wingless-type family member (Wnt) 5a through c-jun N-terminal kinase (JNK) as a regulator of metabolic dysfunction with potential relevance to vascular function. We sought to gain evidence that increased activation of Wnt5a-JNK signaling contributes to impaired endothelial function in patients with diabetes mellitus. We measured flow-mediated dilation of the brachial artery and characterized freshly isolated endothelial cells by protein expression, eNOS activation, and nitric oxide production in 85 subjects with type 2 diabetes mellitus (n=42) and age- and sex-matched nondiabetic controls (n=43) and in human aortic endothelial cells treated with Wnt5a. Endothelial cells from patients with diabetes mellitus displayed 1.3-fold higher Wnt5a levels (P=0.01) along with 1.4-fold higher JNK activation (P<0.01) without a difference in total JNK levels. Higher JNK activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction (r=0.53, P=0.02). Inhibition of Wnt5a and JNK signaling restored insulin and A23187-mediated eNOS activation and improved nitric oxide production in endothelial cells from patients with diabetes mellitus. In endothelial cells from nondiabetic controls, rWnt5a treatment inhibited eNOS activation replicating the diabetic endothelial phenotype. In human aortic endothelial cells, Wnt5a-induced impairment of eNOS activation and nitric oxide production was reversed by Wnt5a and JNK inhibition. Our findings demonstrate that noncanonical Wnt5a signaling and JNK activity contribute to vascular insulin resistance and endothelial dysfunction and may represent a novel therapeutic opportunity to protect the vasculature in patients with diabetes mellitus. © 2016 American Heart

  17. SP-Designer: a user-friendly program for designing species-specific primer pairs from DNA sequence alignments.

    PubMed

    Villard, Pierre; Malausa, Thibaut

    2013-07-01

    SP-Designer is an open-source program providing a user-friendly tool for the design of specific PCR primer pairs from a DNA sequence alignment containing sequences from various taxa. SP-Designer selects PCR primer pairs for the amplification of DNA from a target species on the basis of several criteria: (i) primer specificity, as assessed by interspecific sequence polymorphism in the annealing regions, (ii) the biochemical characteristics of the primers and (iii) the intended PCR conditions. SP-Designer generates tables, detailing the primer pair and PCR characteristics, and a FASTA file locating the primer sequences in the original sequence alignment. SP-Designer is Windows-compatible and freely available from http://www2.sophia.inra.fr/urih/sophia_mart/sp_designer/info_sp_designer.php. © 2013 John Wiley & Sons Ltd.

  18. ATF3 mediates the inhibitory action of TNF-α on osteoblast differentiation through the JNK signaling pathway.

    PubMed

    Jeong, Byung-Chul

    2018-05-15

    Tumor necrosis factor (TNF)-α, which is a proinflammatory cytokine, inhibits osteoblast differentiation under diverse inflammatory conditions. Activating transcription factor 3 (ATF3), which is a member of the ATF/cAMP response element-binding protein family of transcription factors, has been implicated in the regulation of cell proliferation and differentiation. However, the precise interactions between ATF3 and the TNF-α signaling pathway in the regulation of osteoblast differentiation remain unclear. In this study, we examined the role of ATF3 in the TNF-α-mediated inhibition of osteoblast differentiation and investigated the signaling pathways involved. The treatment of cells with TNF-α downregulated osteogenic markers, but significantly upregulated the expression of Atf3. The inhibition of Atf3 by small interfering RNAs rescued osteogenesis, which was inhibited by TNF-α. Conversely, the enforced expression of Atf3 enhanced the TNF-α-mediated inhibition of osteoblast differentiation, as revealed by the measurement of osteogenic markers and alkaline phosphatase staining. Mechanistically, TNF-α-induced Atf3 expression was significantly suppressed by the inhibition of the c-Jun N-terminal kinase (JNK) pathway. Furthermore, the overexpression of Atf3 did not affect the rescue effect that inhibiting TNF-α expression using a JNK inhibitor had on alkaline phosphatase activity and mineralization. Taken together, these results indicate that ATF3 mediates the inhibitory action of TNF-α on osteoblast differentiation and that the TNF-α-activated JNK pathway is responsible for the induction of Atf3 expression. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Novel mechanism of JNK pathway activation by adenoviral E1A

    PubMed Central

    Morrison, Helen; Pospelova, Tatiana V.; Pospelov, Valery A.; Herrlich, Peter

    2014-01-01

    The adenoviral oncoprotein E1A influences cellular regulation by interacting with a number of cellular proteins. In collaboration with complementary oncogenes, E1A fully transforms primary cells. As part of this action, E1A inhibits transcription of c-Jun:Fos target genes while promoting that of c-Jun:ATF2-dependent genes including jun. Both c-Jun and ATF2 are hyperphosphorylated in response to E1A. In the current study, E1A was fused with the ligand binding domain of the estrogen receptor (E1A-ER) to monitor the immediate effect of E1A activation. With this approach we now show that E1A activates c-Jun N-terminal kinase (JNK), the upstream kinases MKK4 and MKK7, as well as the small GTPase Rac1. Activation of the JNK pathway requires the N-terminal domain of E1A, and, importantly, is independent of transcription. In addition, it requires the presence of ERM proteins. Downregulation of signaling components upstream of JNK inhibits E1A-dependent JNK/c-Jun activation. Taking these findings together, we show that E1A activates the JNK/c-Jun signaling pathway upstream of Rac1 in a transcription-independent manner, demonstrating a novel mechanism of E1A action. PMID:24742962

  20. The nucleolus as a stress sensor: JNK2 inactivates the transcription factor TIF-IA and down-regulates rRNA synthesis.

    PubMed

    Mayer, Christine; Bierhoff, Holger; Grummt, Ingrid

    2005-04-15

    Cells respond to a variety of extracellular and intracellular forms of stress by down-regulating rRNA synthesis. We have investigated the mechanism underlying stress-dependent inhibition of RNA polymerase I (Pol I) transcription and show that the Pol I-specific transcription factor TIF-IA is inactivated upon stress. Inactivation is due to phosphorylation of TIF-IA by c-Jun N-terminal kinase (JNK) at a single threonine residue (Thr 200). Phosphorylation at Thr 200 impairs the interaction of TIF-IA with Pol I and the TBP-containing factor TIF-IB/SL1, thereby abrogating initiation complex formation. Moreover, TIF-IA is translocated from the nucleolus into the nucleoplasm. Substitution of Thr 200 by valine as well as knock-out of Jnk2 prevent inactivation and translocation of TIF-IA, leading to stress-resistance of Pol I transcription. Our data identify TIF-IA as a downstream target of the JNK pathway and suggest a critical role of JNK2 to protect rRNA synthesis against the harmful consequences of cellular stress.

  1. Protective Effects of Astaxanthin on ConA-Induced Autoimmune Hepatitis by the JNK/p-JNK Pathway-Mediated Inhibition of Autophagy and Apoptosis

    PubMed Central

    Liu, Tong; Wang, Junshan; Dai, Weiqi; Wang, Fan; Zheng, Yuanyuan; Chen, Kan; Li, Sainan; Abudumijiti, Huerxidan; Zhou, Zheng; Wang, Jianrong; Lu, Wenxia; Zhu, Rong; Yang, Jing; Zhang, Huawei; Yin, Qin; Wang, Chengfen; Zhou, Yuqing; Lu, Jie; Zhou, Yingqun; Guo, Chuanyong

    2015-01-01

    Objective Astaxanthin, a potent antioxidant, exhibits a wide range of biological activities, including antioxidant, atherosclerosis and antitumor activities. However, its effect on concanavalin A (ConA)-induced autoimmune hepatitis remains unclear. The aim of this study was to investigate the protective effects of astaxanthin on ConA-induced hepatitis in mice, and to elucidate the mechanisms of regulation. Materials and Methods Autoimmune hepatitis was induced in in Balb/C mice using ConA (25 mg/kg), and astaxanthin was orally administered daily at two doses (20 mg/kg and 40 mg/kg) for 14 days before ConA injection. Levels of serum liver enzymes and the histopathology of inflammatory cytokines and other maker proteins were determined at three time points (2, 8 and 24 h). Primary hepatocytes were pretreated with astaxanthin (80 μM) in vitro 24 h before stimulation with TNF-α (10 ng/ml). The apoptosis rate and related protein expression were determined 24 h after the administration of TNF-α. Results Astaxanthin attenuated serum liver enzymes and pathological damage by reducing the release of inflammatory factors. It performed anti-apoptotic effects via the descending phosphorylation of Bcl-2 through the down-regulation of the JNK/p-JNK pathway. Conclusion This research firstly expounded that astaxanthin reduced immune liver injury in ConA-induced autoimmune hepatitis. The mode of action appears to be downregulation of JNK/p-JNK-mediated apoptosis and autophagy. PMID:25761053

  2. Persistency of use of COX-2-specific inhibitors and non-specific non-steroidal anti-inflammatory drugs (NSAIDs) in Quebec.

    PubMed

    Moride, Y; Ducruet, T; Rochon, S; Lavoie, F

    2003-11-01

    The effectiveness of pharmacological therapies is dependent in part on patient persistency with the prescribed therapeutic regimen. In the case of non-specific non-steroidal anti-inflammatory drugs (NSAIDs), effectiveness is often compromised by undesirable side-effects, poor compliance or discontinuation of therapy. While patterns of utilization of non-specific NSAIDs have been investigated, few data are available on the patterns of persistency for cyclooxygenase (COX)-2-specific inhibitors. This study used a provincial health-care system database in Quebec, Canada, to determine the duration of treatment in new users of COX-2-specific inhibitors and non-specific NSAIDs over the first 3 months of treatment, and to characterize the factors associated with treatment persistency. Results demonstrate that the median duration of treatment was longer among patients initially prescribed COX-2-specific inhibitors (30 days and 23 days for celecoxib and rofecoxib respectively) than in those prescribed non-selective NSAIDs (10 days). Although the percentage of patients remaining on COX-2-specific drugs declined over the course of treatment, few patients on either celecoxib or rofecoxib switched drugs, either to the other COX-2-specific inhibitor or to non-specific NSAIDs. Factors associated with persistent drug use were: COX-2-specific inhibitors, age, and the use of gastroprotective agents either at treatment initiation or during follow-up. Dosage, chronic disease score and prescriber's specialty were only marginally associated with persistency. Prior use of gastroprotective agents was associated with lower persistency. Although the limitations of this study, which included lack of information on the indication for the prescription and the reason for switch or discontinuation, preclude definite conclusions regarding patterns of use of these drugs, the data suggest that the use of COX-2-specific inhibitors may result in increased persistency with treatment.

  3. In Silico Analysis of the Potential of the Active Compounds Fucoidan and Alginate Derived from Sargassum Sp. as Inhibitors of COX-1 and COX-2

    PubMed Central

    Dewi, Lestari

    2016-01-01

    Introduction: The enzyme cyclooxygenase (COX) is an enzyme that catalyzes the formation of one of the mediators of inflammation, the prostaglandins. Inhibition of COX allegedly can improve inflammation-induced pathological conditions. Aim: The purpose of the present study was to evaluate the potential of Sargassum sp. components, Fucoidan and alginate, as COX inhibitors. Material and methods: The study was conducted by means of a computational (in silico) method. It was performed in two main stages, the docking between COX-1 and COX-2 with Fucoidan, alginate and aspirin (for comparison) and the analysis of the amount of interactions formed and the residues directly involved in the process of interaction. Results: Our results showed that both Fucoidan and alginate had an excellent potential as inhibitors of COX-1 and COX-2. Fucoidan had a better potential as an inhibitor of COX than alginate. COX inhibition was expected to provide a more favorable effect on inflammation-related pathological conditions. Conclusion: The active compounds Fucoidan and alginate derived from Sargassum sp. were suspected to possess a good potential as inhibitors of COX-1 and COX-2. PMID:27594740

  4. Preparation of 6-substituted quinoxaline JSP-1 inhibitors by microwave accelerated nucleophilic substitution.

    PubMed

    Zhang, Li; Qiu, Beiying; Li, Xin; Wang, Xin; Li, Jingya; Zhang, Yongliang; Liu, Jian; Li, Jia; Shen, Jingkang

    2006-12-21

    A small library of 6-aminoquinoxalines has been prepared by nucleophilic substitution of 6-fluoroquinoxaline with amines and nitrogen-containing heterocycles under computer-controlled microwave irradiation. Some compounds were found to be potent inhibitors of JNK Stimulatory Phosphatase-1 (JSP-1) in an in vitro biological assay.

  5. Demethylase Inhibitor Fungicide Resistance in Pyrenophora teres f. sp. teres Associated with Target Site Modification and Inducible Overexpression of Cyp51

    PubMed Central

    Mair, Wesley J.; Deng, Weiwei; Mullins, Jonathan G. L.; West, Samuel; Wang, Penghao; Besharat, Naghmeh; Ellwood, Simon R.; Oliver, Richard P.; Lopez-Ruiz, Francisco J.

    2016-01-01

    Pyrenophora teres f. sp. teres is the cause of net form of net blotch (NFNB), an economically important foliar disease in barley (Hordeum vulgare). Net and spot forms of net blotch are widely controlled using site-specific systemic fungicides. Although resistance to succinate dehydrogenase inhibitors and quinone outside inhibitors has been addressed before in net blotches, mechanisms controlling demethylation inhibitor resistance have not yet been reported at the molecular level. Here we report the isolation of strains of NFNB in Australia since 2013 resistant to a range of demethylase inhibitor fungicides. Cyp51A:KO103-A1, an allele with the mutation F489L, corresponding to the archetype F495I in Aspergillus fumigatus, was only present in resistant strains and was correlated with resistance factors to various demethylase inhibitors ranging from 1.1 for epoxiconazole to 31.7 for prochloraz. Structural in silico modeling of the sensitive and resistant CYP51A proteins docked with different demethylase inhibitor fungicides showed how the interaction of F489L within the heme cavity produced a localized constriction of the region adjacent to the docking site that is predicted to result in lower binding affinities. Resistant strains also displayed enhanced induced expression of the two Cyp51A paralogs and of Cyp51B genes. While Cyp51B was found to be constitutively expressed in the absence of fungicide, Cyp51A was only detected at extremely low levels. Under fungicide induction, expression of Cyp51B, Cyp51A2, and Cyp51A1 was shown to be 1.6-, 3,- and 5.3-fold higher, respectively in the resistant isolate compared to the wild type. These increased levels of expression were not supported by changes in the promoters of any of the three genes. The implications of these findings on demethylase inhibitor activity will require current net blotch management strategies to be reconsidered in order to avoid the development of further resistance and preserve the lifespan of

  6. Investigation of SP94 Peptide as a Specific Probe for Hepatocellular Carcinoma Imaging and Therapy

    PubMed Central

    Li, Yanli; Hu, Yan; Xiao, Jie; Liu, Guobing; Li, Xiao; Zhao, Yanzhao; Tan, Hui; Shi, Hongcheng; Cheng, Dengfeng

    2016-01-01

    SP94 (SFSIIHTPILPL), a novel peptide, has shown specific binding to hepatocellular carcinoma (HCC) cells. We aimed to investigate the capability of SP94 as a targeting probe for HCC imaging and therapy following labeling with technetium-99m (99mTc) and rhenium-188 (188Re). HYNIC-SP94 was prepared by solid phase synthesis and then labeled with 99mTc. Cell competitive binding, internalization assay, in vitro and in vivo stability, biodistribution and micro-single photon emission computed tomography /computed tomography (SPECT/CT) imaging studies were performed to investigate the capability of 99mTc tricine-EDDA/HYNIC-SP94 as a specific HCC imaging probe. Initial promising targeting results inspired evaluation of its therapeutic effect when labeled by 188Re. HYNIC-SP94 was then labeled again with 188Re to perform cell apoptosis, microSPECT/CT imaging evaluation and immunohistochemistry. Huh-7 cells exhibited typical apoptotic changes after 188Re irradiation. According to 99mTc tricine-EDDA/HYNIC-SP94 microSPECT/CT imaging, tumor uptake was significantly decreased compared with that of pre-treatment with 188Re-HYNIC-SP94. The immunohistochemistry also displayed obvious necrosis and apoptosis as well as inhibition of proliferation in the 188Re-HYNIC-SP94 treatment group. The results supported that 99mTc tricine-EDDA/HYNIC-SP94 is able to target HCC cells and 188Re-HYNIC- SP94 holds potential as a therapeutic agent for HCC, making 99mTc/188Re-HYNIC-SP94 a promising targeting probe for HCC imaging and therapy. PMID:27649935

  7. Increased levels of cerebrospinal fluid JNK3 associated with amyloid pathology: links to cognitive decline

    PubMed Central

    Gourmaud, Sarah; Paquet, Claire; Dumurgier, Julien; Pace, Clarisse; Bouras, Constantin; Gray, Françoise; Laplanche, Jean-Louis; Meurs, Eliane F.; Mouton-Liger, François; Hugon, Jacques

    2015-01-01

    Background Alzheimer disease is characterized by cognitive decline, senile plaques of β-amyloid (Aβ) peptides, neurofibrillary tangles composed of hyperphosphorylated τ proteins and neuronal loss. Aβ and τ are useful markers in the cerebrospinal fluid (CSF). C-Jun N-terminal kinases (JNKs) are serine-threonine protein kinases activated by phosphorylation and involved in neuronal death. Methods In this study, Western blots, enzyme-linked immunosorbent assay and histological approaches were used to assess the concentrations of Aβ, τ and JNK isoforms in postmortem brain tissue samples (10 Alzheimer disease and 10 control) and in CSF samples from 30 living patients with Alzheimer disease and 27 controls with neurologic disease excluding Alzheimer disease. Patients with Alzheimer disease were followed for 1–3 years and assessed using Mini–Mental State Examination scores. Results The biochemical and morphological results showed a significant increase of JNK3 and phosphorylated JNK levels in patients with Alzheimer disease, and JNK3 levels correlated with Aβ42 levels. Confocal microscopy revealed that JNK3 was associated with Aβ in senile plaques. The JNK3 levels in the CSF were significantly elevated in patients with Alzheimer disease and correlated statistically with the rate of cognitive decline in a mixed linear model. Limitations The study involved different samples grouped into 3 small cohorts. Evaluation of JNK3 in CSF was possible only with immunoblot analysis. Conclusion We found that JNK3 levels are increased in brain tissue and CSF from patients with Alzheimer disease. The finding that increased JNK3 levels in CSF could reflect the rate of cognitive decline is new and merits further investigation. PMID:25455349

  8. Specific inhibitors of mammalian DNA polymerase species.

    PubMed

    Mizushina, Yoshiyuki

    2009-06-01

    In screening of selective inhibitors of eukaryotic DNA polymerases (pols) for 15 years, more than 100 inhibitors have been discovered from natural and chemical sources. Some compounds selectively inhibit the activities of mammalian pols, and in particular, dehydroaltenusin and curcumin derivatives, such as monoacetyl-curcumin, were found to be specific inhibitors of pol alpha and pol lambda, respectively. Dehydroaltenusin was isolated from a fungus (Alternaria tennuis), and this compound inhibited cell proliferation of human cancer cell lines by arresting the cells at the S-phase, and was effective in suppressing the growth on nude mice of solid tumors of human cervical cancer cell line HeLa. Curcumin derivatives had anti-12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammatory activity with the same tendency as pol lambda inhibitory activity. These compounds might be useful not only as "molecular probes" for pol research, but also as biomedical and chemotherapeutic drugs for anti-cancer or anti-inflammation.

  9. Diet-induced obesity mediated by the JNK/DIO2 signal transduction pathway

    PubMed Central

    Vernia, Santiago; Cavanagh-Kyros, Julie; Barrett, Tamera; Jung, Dae Young; Kim, Jason K.; Davis, Roger J.

    2013-01-01

    The cJun N-terminal kinase (JNK) signaling pathway is a key mediator of metabolic stress responses caused by consuming a high-fat diet, including the development of obesity. To test the role of JNK, we examined diet-induced obesity in mice with targeted ablation of Jnk genes in the anterior pituitary gland. These mice exhibited an increase in the pituitary expression of thyroid-stimulating hormone (TSH), an increase in the blood concentration of thyroid hormone (T4), increased energy expenditure, and markedly reduced obesity compared with control mice. The increased amount of pituitary TSH was caused by reduced expression of type 2 iodothyronine deiodinase (Dio2), a gene that is required for T4-mediated negative feedback regulation of TSH expression. These data establish a molecular mechanism that accounts for the regulation of energy expenditure and the development of obesity by the JNK signaling pathway. PMID:24186979

  10. Mis16 Independently Recognizes Histone H4 and the CENP-ACnp1-Specific Chaperone Scm3sp

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    An, Sojin; Kim, Hanseong; Cho, Uhn-Soo

    2015-09-04

    CENP-A is a centromere-specific histone H3 variant that is required for kinetochore assembly and accurate chromosome segregation. For it to function properly, CENP-A must be specifically localized to centromeres. In fission yeast, Scm3sp and the Mis18 complex, composed of Mis16, Eic1, and Mis18, function as a CENP-ACnp1-specific chaperone and a recruiting factor, respectively, and together ensure accurate delivery of CENP-ACnp1 to centromeres. Although how Scm3sp specifically recognizes CENP-ACnp1 has been revealed recently, the recruiting mechanism of CENP-ACnp1 via the Mis18 complex remains unknown. In this study, we have determined crystal structures of Schizosaccharomyces japonicus Mis16 alone and in complex withmore » the helix 1 of histone H4 (H4α1). Crystal structures followed by mutant analysis and affinity pull-downs have revealed that Mis16 recognizes both H4α1 and Scm3sp independently within the CENP-ACnp1/H4:Scm3sp complex. This observation suggests that Mis16 gains CENP-ACnp1 specificity by recognizing both Scm3sp and histone H4. Our studies provide insights into the molecular mechanisms underlying specific recruitment of CENP-ACnp1/H4:Scm3sp into centromeres.« less

  11. AIP1 recruits phosphatase PP2A to ASK1 in tumor necrosis factor-induced ASK1-JNK activation.

    PubMed

    Min, Wang; Lin, Yan; Tang, Shibo; Yu, Luyang; Zhang, Haifeng; Wan, Ting; Luhn, Tricia; Fu, Haian; Chen, Hong

    2008-04-11

    Previously we have shown that AIP1 (apoptosis signal-regulating kinase [ASK]1-interacting protein 1), a novel member of the Ras-GAP protein family, facilitates dephosphorylation of ASK1 at pSer967 and subsequently 14-3-3 release from ASK1, leading to enhanced ASK1-JNK signaling. However, the phosphatase(s) responsible for ASK1 dephosphorylation at pSer967 has not been identified. In the present study, we identified protein phosphatase (PP)2A as a potential phosphatase in vascular endothelial cells (ECs). Tumor necrosis factor (TNF)-induced dephosphorylation of ASK1 pSer967 in ECs was blocked by PP2A inhibitor okadaic acid. Overexpression of PP2A catalytic subunit induced dephosphorylation of ASK1 pSer967 and activation of c-Jun N-terminal kinase (JNK). In contrast, a catalytic inactive form of PP2A or PP2A small interfering RNA blunted TNF-induced dephosphorylation of ASK1 pSer967 and activation of JNK without effects on NF-kappaB activation. Whereas AIP1, via its C2 domain, binds to ASK1, PP2A binds to the GAP domain of AIP1. Endogenous AIP1-PP2A complex can be detected in the resting state, and TNF induces a complex formation of AIP1-PP2A with ASK1. Furthermore, TNF-induced association of PP2A with ASK1 was diminished in AIP1-knockdown ECs, suggesting a critical role of AIP1 in recruiting PP2A to ASK1. TNF-signaling molecules TRAF2 and RIP1, known to be in complex with AIP1 and activate AIP1 by phosphorylating AIP1 at Ser604, are critical for TNF-induced ASK1 dephosphorylation. Finally, PP2A and AIP1 cooperatively induce activation of ASK1-JNK signaling and EC apoptosis, as demonstrated by both overexpression and small interfering RNA knockdown approaches. Taken together, our data support a critical role of PP2A-AIP1 complex in TNF-induced activation of ASK1-JNK apoptotic signaling.

  12. Non-nucleoside reverse transcriptase inhibitor efavirenz increases monolayer permeability of human coronary artery endothelial cells

    PubMed Central

    Jamaluddin, Md Saha; Lin, Peter H.; Yao, Qizhi; Chen, Changyi

    2009-01-01

    Highly active antiretroviral therapy (HAART) is often associated with endothelial dysfunction and cardiovascular complications. In this study, we determined whether HIV non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) could increase endothelial permeability. Human coronary artery endothelial cells (HCAECs) were treated with EFV (1, 5 and 10 µg/ml) and endothelial permeability was determined by a transwell system with a fluorescence-labeled dextran tracer. HCAECs treated with EFV showed a significant increase of endothelial permeability in a concentration-dependent manner. With real time PCR analysis, EFV significantly reduced the mRNA levels of tight junction proteins claudin-1, occludin, zonula occluden-1 and junctional adhesion molecule-1 compared with controls (P < 0.05). Protein levels of these tight junction molecules were also reduced substantially in the EFV-treated cells by western blot and flow cytometry analyses. In addition, EFV also increased superoxide anion production with dihydroethidium and cellular glutathione assays, while it decreased mitochondrial membrane potential with JC-staining. Antioxidants (ginkgolide B and MnTBAP) effectively blocked EFV-induced endothelial permeability and mitochondrial dysfunction. Furthermore, EFV increased the phosphorylation of MAPK JNK and IκBα, thereby increasing NFκB translocation to the nucleus. Chemical JNK inhibitor and dominant negative mutant JNK and IkBa adenoviruses effectively blocked the effects of EFV on HCAECs. Thus, EFV increases endothelial permeability which may be due to the decrease of tight junction proteins and the increase of superoxide anion. JNK and NFκB activation may be directly involved in the signal transduction pathway of EFV action in HCAECs. PMID:19674747

  13. Induction of c-fos expression through JNK-mediated TCF/Elk-1 phosphorylation.

    PubMed Central

    Cavigelli, M; Dolfi, F; Claret, F X; Karin, M

    1995-01-01

    Growth factors induce c-fos transcription by stimulating phosphorylation of transcription factor TCF/Elk-1, which binds to the serum response element (SRE). Under such conditions Elk-1 could be phosphorylated by the mitogen-activated protein kinases (MAPKs) ERK1 and ERK2. However, c-fos transcription and SRE activity are also induced by stimuli, such as UV irradiation and activation of the protein kinase MEKK1, that cause only an insignificant increase in ERK1/2 activity. However, both of these stimuli strongly activate two other MAPKs, JNK1 and JNK2, and stimulate Elk-1 transcriptional activity and phosphorylation. We find that the JNKs are the predominant Elk-1 activation domain kinases in extracts of UV-irradiated cells and that immunopurified JNK1/2 phosphorylate Elk-1 on the same major sites recognized by ERK1/2, that potentiate its transcriptional activity. Finally, we show that UV irradiation, but not serum or phorbol esters, stimulate translocation of JNK1 to the nucleus. As Elk-1 is most likely phosphorylated while bound to the c-fos promoter, these results suggest that UV irradiation and MEKK1 activation stimulate TCF/Elk-1 activity through JNK activation, while growth factors induce c-fos through ERK activation. Images PMID:8846788

  14. Specific inhibition of c-Jun N-terminal kinase delays preterm labour and reduces mortality

    PubMed Central

    Pirianov, Grisha; MacIntyre, David A; Lee, Yun; Waddington, Simon N; Terzidou, Vasso; Mehmet, Huseyin; Bennett, Phillip R

    2015-01-01

    Preterm labour (PTL) is commonly associated with infection and/or inflammation. Lipopolysaccharide (LPS) from different bacteria can be used to independently or mutually activate Jun N-terminal kinase (JNK)/AP1- or NF-κB-driven inflammatory pathways that lead to PTL. Previous studies using Salmonella abortus LPS, which activates both JNK/AP-1 and NF-κB, showed that selective inhibition of NF-κB delays labour and improves pup outcome. Where labour is induced using Escherichia coli LPS (O111), which upregulates JNK/AP-1 but not NF-κB, inhibition of JNK/AP-1 activation also delays labour. In this study, to determine the potential role of JNK as a therapeutic target in PTL, we investigated the specific contribution of JNK signalling to S. Abortus LPS-induced PTL in mice. Intrauterine administration of S. Abortus LPS to pregnant mice resulted in the activation of JNK in the maternal uterus and fetal brain, upregulation of pro-inflammatory proteins COX-2, CXCL1, and CCL2, phosphorylation of cPLA2 in myometrium, and induction of PTL. Specific inhibition of JNK by co-administration of specific D-JNK inhibitory peptide (D-JNKI) delayed LPS-induced preterm delivery and reduced fetal mortality. This is associated with inhibition of myometrial cPLA2 phosphorylation and proinflammatory proteins synthesis. In addition, we report that D-JNKI inhibits the activation of JNK/JNK3 and caspase-3, which are important mediators of neural cell death in the neonatal brain. Our data demonstrate that specific inhibition of TLR4-activated JNK signalling pathways has potential as a therapeutic approach in the management of infection/inflammation-associated PTL and prevention of the associated detrimental effects to the neonatal brain. PMID:26183892

  15. Epiregulin (EREG) is upregulated through an IL-1β autocrine loop in Caco-2 epithelial cells with reduced CFTR function.

    PubMed

    Massip-Copiz, Macarena; Clauzure, Mariángeles; Valdivieso, Ángel G; Santa-Coloma, Tomás A

    2018-03-01

    CFTR is a cAMP-regulated chloride channel, whose mutations produce cystic fibrosis. The impairment of CFTR activity increases the intracellular Cl - concentration, which in turn produces an increased interleukin-1β (IL-1β) secretion. The secreted IL-1β then induces an autocrine positive feedback loop, further stimulating IL-1β priming and secretion. Since IL-1β can transactivate the epidermal growth factor receptor (EGFR), we study here the levels of expression for different EGFR ligands in Caco-2/pRS26 cells (expressing shRNA against CFTR resulting in a reduced CFTR expression and activity). The epiregulin (EREG), amphiregulin (AREG), and heparin binding EGF like growth factor (HBEGF) mRNAs, were found overexpressed in Caco-2/pRS26 cells. The EREG mRNA had the highest differential expression and was further characterized. In agreement with its mRNA levels, Western blots (WB) showed increased EREG levels in CFTR-impaired cells. In addition, EREG mRNA and protein levels were stimulated by incubation with exogenous IL-1β and inhibited by the Interleukin 1 receptor type I (IL1R1) antagonist IL1RN, suggesting that the overexpression of EREG is a consequence of the autocrine IL-1β loop previously described for these cells. In addition, the JNK inhibitor SP600125, and the EGFR inhibitors AG1478 and PD168393, also had an inhibitory effect on EREG expression, suggesting that EGFR, activated in Caco-2/pRS26 cells, is involved in the observed EREG upregulation. In conclusion, in Caco-2 CFTR-shRNA cells, the EGFR ligand EREG is overexpressed due to an active IL-1β autocrine loop that indirectly activates EGFR, constituting new signaling effectors for the CFTR signaling pathway, downstream of CFTR, Cl - , and IL-1β. © 2017 Wiley Periodicals, Inc.

  16. Zaprinast activates MAPKs, NFκB, and Akt and induces the expressions of inflammatory genes in microglia.

    PubMed

    Lee, Heung-Soon; Kwon, Soon-Ho; Ham, Ji-Eun; Lee, Joo Young; Kim, Dong-Hoon; Shin, Kyung-Ho; Choi, Sang-Hyun

    2012-07-01

    Previously, the authors reported that zaprinast, an inhibitor of cGMP-selective phosphodiesterases, induced the secretions of TNF-α and IL-1β by microglia and enhanced the induction of iNOS by lipopolysaccharide (LPS). In this study, the signaling mechanism responsible for microglial activation by zaprinast was investigated and the effects of zaprinast and LPS on microglial activation were compared. Zaprinast was found to activate ERK1/2, p38 MAPK, JNK, NFκB, and PI3K/Akt, and subsequently, induce the mRNA expressions of IL-1α, IL-1β, TNF-α, CCL2, CCL4, CXCL1, CXCL2, and CD14. Associations between signaling pathways and gene expressions were examined by treating microglia with signal inhibitors. PDTC inhibited the induction of all the above genes by zaprinast, and SB203580 inhibited all genes except CXCL1. SP600125, PD98059, and LY294002 inhibited the induction of at least CCL2. Microglial activation by zaprinast was then compared with full-blown activation by LPS. The zaprinast-induced phosphorylations of MAPKs and IκB were less prompt than LPS-induced phosphorylations. IκB degradation by LPS was significant at 10min and did not return to normal, whereas zaprinast induced a later, transient degradation. LPS induced the mRNA expressions of IL-1β, TNF-α, IL-6, CCL2, iNOS, and COX-2, and although zaprinast significantly induced the expressions of all except IL-6 and iNOS, these inductions were far less than those induced by LPS. Collectively, zaprinast was found to upregulate microglial activity mainly via NFκB and p38 MAPK signaling and the subsequent expressions of inflammatory genes. Although, zaprinast was found to have obvious effects on microglia, these were weaker than the effects of LPS. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. ROS regulation of axonal mitochondrial transport is mediated by Ca2+ and JNK in Drosophila

    PubMed Central

    Liao, Pin-Chao; Tandarich, Lauren C.

    2017-01-01

    Mitochondria perform critical functions including aerobic ATP production and calcium (Ca2+) homeostasis, but are also a major source of reactive oxygen species (ROS) production. To maintain cellular function and survival in neurons, mitochondria are transported along axons, and accumulate in regions with high demand for their functions. Oxidative stress and abnormal mitochondrial axonal transport are associated with neurodegenerative disorders. However, we know little about the connection between these two. Using the Drosophila third instar larval nervous system as the in vivo model, we found that ROS inhibited mitochondrial axonal transport more specifically, primarily due to reduced flux and velocity, but did not affect transport of other organelles. To understand the mechanisms underlying these effects, we examined Ca2+ levels and the JNK (c-Jun N-terminal Kinase) pathway, which have been shown to regulate mitochondrial transport and general fast axonal transport, respectively. We found that elevated ROS increased Ca2+ levels, and that experimental reduction of Ca2+ to physiological levels rescued ROS-induced defects in mitochondrial transport in primary neuron cell cultures. In addition, in vivo activation of the JNK pathway reduced mitochondrial flux and velocities, while JNK knockdown partially rescued ROS-induced defects in the anterograde direction. We conclude that ROS have the capacity to regulate mitochondrial traffic, and that Ca2+ and JNK signaling play roles in mediating these effects. In addition to transport defects, ROS produces imbalances in mitochondrial fission-fusion and metabolic state, indicating that mitochondrial transport, fission-fusion steady state, and metabolic state are closely interrelated in the response to ROS. PMID:28542430

  18. A sestrin-dependent Erk/Jnk/p38 MAPK activation complex inhibits immunity during ageing

    PubMed Central

    Lanna, Alessio; Gomes, Daniel C O; Muller-Durovic, Bojana; McDonnell, Thomas; Escors, David; Gilroy, Derek W; Lee, Jun Hee; Karin, Michael; Akbar, Arne N

    2016-01-01

    Mitogen activated protein kinases (MAPKs) including Erk, Jnk and p38 regulate diverse cellular functions, and are thought to be controlled by independent upstream activation cascades. Here we show that the sestrins bind to and co-ordinate simultaneous Erk, Jnk and p38 MAPK activation in T lymphocytes within a new immune-inhibitory complex (sestrin-MAPK Activation Complex; sMAC). Whereas sestrin ablation resulted in broad reconstitution of immune function in stressed T cells, inhibition of individual MAPKs only allowed partial functional recovery. T cells from old humans and mice were more likely to form the sMAC, and disruption of this complex restored antigen-specific functional responses in these cells. Correspondingly, sestrin deficiency or simultaneous inhibition of all three MAPKs enhanced vaccine responsiveness in old mice. Thus, disruption of sMAC provides a foundation for rejuvenating immunity during ageing. PMID:28114291

  19. Heterofibrins: inhibitors of lipid droplet formation from a deep-water southern Australian marine sponge, Spongia (Heterofibria) sp.

    PubMed

    Salim, Angela A; Rae, James; Fontaine, Frank; Conte, Melissa M; Khalil, Zeinab; Martin, Sally; Parton, Robert G; Capon, Robert J

    2010-07-21

    A bioassay-guided search for inhibitors of lipid droplet formation in a deep-water southern Australian marine sponge, Spongia (Heterofibria) sp., yielded six new compounds, fatty acids heterofibrins A1 (1) and B1 (4), along with related monolactyl and dilactyl esters, heterofibrins A2 (2), B2 (5), A3 (3) and B3 (6). Heterofibrin structures were assigned on the basis of detailed spectroscopic analysis, with comparison to chiral synthetic model compounds. All heterofibrins possess a diyne-ene moiety, while the monolactyl and dilactyl moiety featured in selected heterofibrins is unprecedented in the natural products literature. SAR by co-metabolite studies on the heterofibrins confirmed them to be non-cytotoxic, with the carboxylic acids 1 and 4 inhibiting lipid droplet formation in A431 fibroblast cell lines. Such inhibitors have potential application in the management of obesity, diabetes and atherosclerosis

  20. T-bet-mediated Tim-3 expression dampens monocyte function during chronic hepatitis C virus infection.

    PubMed

    Yi, Wenjing; Zhang, Peixin; Liang, Yan; Zhou, Yun; Shen, Huanjun; Fan, Chao; Moorman, Jonathan P; Yao, Zhi Q; Jia, Zhansheng; Zhang, Ying

    2017-03-01

    Hepatitis C virus (HCV) induces a high rate of chronic infection via dysregulation of host immunity. We have previously shown that T-cell immunoglobulin and mucin domain protein-3 (Tim-3) is up-regulated on monocyte/macrophages (M/Mφ) during chronic HCV infection; little is known, however, about the transcription factor that controls its expression in these cells. In this study, we investigated the role of transcription factor, T-box expressed in T cells (T-bet), in Tim-3 expression in M/Mφ in the setting of HCV infection. We demonstrate that T-bet is constitutively expressed in resting CD14 + M/Mφ in the peripheral blood. M/Mφ from chronically HCV-infected individuals exhibit a significant increase in T-bet expression that positively correlates with an increased level of Tim-3 expression. Up-regulation of T-bet is also observed in CD14 + M/Mφ incubated with HCV + Huh7.5 cells, as well as in primary M/Mφ or monocytic THP-1 cells exposed to HCV core protein in vitro, which is reversible by blocking HCV core/gC1qR interactions. Moreover, the HCV core-induced up-regulation of T-bet and Tim-3 expression in M/Mφ can be abrogated by incubating the cells with SP600125 - an inhibitor for the c-Jun N-terminal kinase (JNK) signalling pathway. Importantly, silencing T-bet gene expression decreases Tim-3 expression and enhances interleukin-12 secretion as well as signal transducer and activator of transcription 1 phosphorylation. These data suggest that T-bet, induced by the HCV core/gC1qR interaction, enhances Tim-3 expression via the JNK pathway, leading to dampened M/Mφ function during HCV infection. These findings reveal a novel mechanism for Tim-3 regulation via T-bet during HCV infection, providing new targets to combat this global epidemic viral disease. © 2016 John Wiley & Sons Ltd.

  1. PARP1-mediated necrosis is dependent on parallel JNK and Ca2+/calpain pathways

    PubMed Central

    Douglas, Diana L.; Baines, Christopher P.

    2014-01-01

    ABSTRACT Poly(ADP-ribose) polymerase-1 (PARP1) is a nuclear enzyme that can trigger caspase-independent necrosis. Two main mechanisms for this have been proposed: one involving RIP1 and JNK kinases and mitochondrial permeability transition (MPT), the other involving calpain-mediated activation of Bax and mitochondrial release of apoptosis-inducing factor (AIF). However, whether these two mechanisms represent distinct pathways for PARP1-induced necrosis, or whether they are simply different components of the same pathway has yet to be tested. Mouse embryonic fibroblasts (MEFs) were treated with either N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) or β-Lapachone, resulting in PARP1-dependent necrosis. This was associated with increases in calpain activity, JNK activation and AIF translocation. JNK inhibition significantly reduced MNNG- and β-Lapachone-induced JNK activation, AIF translocation, and necrosis, but not calpain activation. In contrast, inhibition of calpain either by Ca2+ chelation or knockdown attenuated necrosis, but did not affect JNK activation or AIF translocation. To our surprise, genetic and/or pharmacological inhibition of RIP1, AIF, Bax and the MPT pore failed to abrogate MNNG- and β-Lapachone-induced necrosis. In conclusion, although JNK and calpain both contribute to PARP1-induced necrosis, they do so via parallel mechanisms. PMID:25052090

  2. The Core Molecular Machinery Used for Engulfment of Apoptotic Cells Regulates the JNK Pathway Mediating Axon Regeneration in Caenorhabditis elegans.

    PubMed

    Pastuhov, Strahil Iv; Fujiki, Kota; Tsuge, Anna; Asai, Kazuma; Ishikawa, Sho; Hirose, Kazuya; Matsumoto, Kunihiro; Hisamoto, Naoki

    2016-09-14

    The mechanisms that govern the ability of specific neurons to regenerate their axons after injury are not well understood. In Caenorhabditis elegans, the initiation of axon regeneration is positively regulated by the JNK-MAPK pathway. In this study, we identify two components functioning upstream of the JNK pathway: the Ste20-related protein kinase MAX-2 and the Rac-type GTPase CED-10. CED-10, when bound by GTP, interacts with MAX-2 and functions as its upstream regulator in axon regeneration. CED-10, in turn, is activated by axon injury via signals initiated from the integrin α-subunit INA-1 and the nonreceptor tyrosine kinase SRC-1 and transmitted via the signaling module CED-2/CrkII-CED-5/Dock180-CED-12/ELMO. This module is also known to regulate the engulfment of apoptotic cells during development. Our findings thus reveal that the molecular machinery used for engulfment of apoptotic cells also promotes axon regeneration through activation of the JNK pathway. The molecular mechanisms of axon regeneration after injury remain poorly understood. In Caenorhabditis elegans, the initiation of axon regeneration is positively regulated by the JNK-MAPK pathway. In this study, we show that integrin, Rac-GTPase, and several other molecules, all of which are known to regulate engulfment of apoptotic cells during development, also regulate axon regeneration. This signaling module activates the JNK-MAPK cascade via MAX-2, a PAK-like protein kinase that binds Rac. Our findings thus reveal that the molecular machinery used for engulfment of apoptotic cells also promotes axon regeneration through activation of the JNK pathway. Copyright © 2016 the authors 0270-6474/16/369710-12$15.00/0.

  3. JNK Controls the Onset of Mitosis in Planarian Stem Cells and Triggers Apoptotic Cell Death Required for Regeneration and Remodeling

    PubMed Central

    Almuedo-Castillo, María; Crespo, Xenia; Seebeck, Florian; Bartscherer, Kerstin; Salò, Emili; Adell, Teresa

    2014-01-01

    Regeneration of lost tissues depends on the precise interpretation of molecular signals that control and coordinate the onset of proliferation, cellular differentiation and cell death. However, the nature of those molecular signals and the mechanisms that integrate the cellular responses remain largely unknown. The planarian flatworm is a unique model in which regeneration and tissue renewal can be comprehensively studied in vivo. The presence of a population of adult pluripotent stem cells combined with the ability to decode signaling after wounding enable planarians to regenerate a complete, correctly proportioned animal within a few days after any kind of amputation, and to adapt their size to nutritional changes without compromising functionality. Here, we demonstrate that the stress-activated c-jun–NH2–kinase (JNK) links wound-induced apoptosis to the stem cell response during planarian regeneration. We show that JNK modulates the expression of wound-related genes, triggers apoptosis and attenuates the onset of mitosis in stem cells specifically after tissue loss. Furthermore, in pre-existing body regions, JNK activity is required to establish a positive balance between cell death and stem cell proliferation to enable tissue renewal, remodeling and the maintenance of proportionality. During homeostatic degrowth, JNK RNAi blocks apoptosis, resulting in impaired organ remodeling and rescaling. Our findings indicate that JNK-dependent apoptotic cell death is crucial to coordinate tissue renewal and remodeling required to regenerate and to maintain a correctly proportioned animal. Hence, JNK might act as a hub, translating wound signals into apoptotic cell death, controlled stem cell proliferation and differentiation, all of which are required to coordinate regeneration and tissue renewal. PMID:24922054

  4. Andrastins A-C, new protein farnesyltransferase inhibitors produced by Penicillium sp. FO-3929. I. Producing strain, fermentation, isolation, and biological activities.

    PubMed

    Omura, S; Inokoshi, J; Uchida, R; Shiomi, K; Masuma, R; Kawakubo, T; Tanaka, H; Iwai, Y; Kosemura, S; Yamamura, S

    1996-05-01

    New protein farnesyltransferase inhibitors, andrastins A-C, have been discovered in the cultured broth of Penicillium sp. FO-3929. Andrastins extracted from broth supernatant were purified by silica gel chromatography, ODS chromatography and HPLC. The IC50 of andrastins A, B, and C against protein farnesyltransferase were 24.9, 47.1, and 13.3 microM, respectively.

  5. Nobiletin, a citrus flavonoid, activates vasodilator-stimulated phosphoprotein in human platelets through non-cyclic nucleotide-related mechanisms.

    PubMed

    Jayakumar, Thanasekaran; Lin, Kao-Chang; Lu, Wan-Jung; Lin, Chia-Ying; Pitchairaj, Geraldine; Li, Jiun-Yi; Sheu, Joen-Rong

    2017-01-01

    Nobiletin, a bioactive polymethoxylated flavone, has been described to possess a diversity of biological effects through its antioxidant and anti-inflammatory properties. Vasodilator-stimulated phosphoprotein (VASP) is a common substrate for cyclic AMP and cyclic GMP-regulated protein kinases [i.e., cyclic AMP-dependent protein kinase (PKA; also known as protein kinase A) and cyclic GMP-dependent protein kinase (PKG; also known as protein kinase G)] and it has been shown to be directly phosphorylated by protein kinase C (PKC). In the present study, we demonstrate that VASP is phosphorylated by nobiletin in human platelets via a non-cyclic nucleotide-related mechanism. This was confirmed by the use of inhibitors of adenylate cyclase (SQ22536) and guanylate cyclase [1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ)], since they prevented VASP phosphorylation induced by nobiletin. Furthormore, this event was also not affected by specific inhibitors of PKA (H-89), PKG (KT5823) and PKC (Ro318220), representing cyclic nucleotide-dependent pathways upon nobiletin-induced VASP phosphorylation. Similarly, inhibitors of p38 mitogen-activated protein kinase (MAPK; SB203580), extracellular signal-regulated kinase 2 (ERK2; PD98059), c-Jun N-terminal kinase 1 (JNK1; SP600125), Akt (LY294002) and nuclear factor-κB (NF-κB; Bay11-7082) did not affect nobiletin‑induced VASP phosphorylation. Moreover, electron spin resonance, dichlorofluorescein fluorescence and western blotting techniques revealed that nobiletin did not affect hydroxyl radicals (OH•), intracellular reactive oxygen species (ROS) and on protein carbonylation, respectively. Furthermore, the nobiletin‑induced VASP phosphorylation was surprisingly reversed by the intracellular antioxidant, N-acetylcysteine (NAC), but not by the inhibitor of NADPH oxidase, diphenyleneiodonium chloride (DPI). It was surprising to observe the differential effects of nobiletin and NAC on VASP

  6. In vitro metabolism of a novel JNK inhibitor tanzisertib: interspecies differences in oxido-reduction and characterization of enzymes involved in metabolism.

    PubMed

    Atsriku, Christian; Hoffmann, Matthew; Moghaddam, Mehran; Kumar, Gondi; Surapaneni, Sekhar

    2015-01-01

    1. In vitro metabolism of Tanzisertib [(1S,4R)-4-(9-((S)tetrahydrofuran-3-yl)-8-(2,4,6-trifluorophenylamino)-9H-purin-2-ylamino) cyclohexanol], a potent, selective c-Jun amino-terminal kinase (JNK) inhibitor, was investigated in mouse, rat, rabbit, dog, monkey and human hepatocytes over 4 h. The extent of metabolism of [(14)C]tanzisertib was variable, with <10% metabolized in dog and human, <20% metabolized in rabbit and monkey and >75% metabolized in rat and mouse. Primary metabolic pathways in human and dog hepatocytes, were direct glucuronidation and oxidation of cyclohexanol to a keto metabolite, which was subsequently reduced to parent or cis-isomer, followed by glucuronidation. Rat and mouse produced oxidative metabolites and cis-isomer, including direct glucuronides and sulfates of tanzisertib and cis-isomer. 2. Enzymology of oxido-reductive pathways revealed that human aldo-keto reductases AKR1C1, 1C2, 1C3 and 1C4 were responsible for oxido-reduction of tanzisertib, CC-418424 and keto tanzisertib. Characterizations of enzyme kinetics revealed that AKR1C4 had a high affinity for reduction of keto tanzisertib to tanzisertib compared to other isoforms. These results demonstrate unique stereoselectivity of the reductive properties documented by human AKR1C enzymes for the same substrate. 3. Characterization of UGT isoenzymes in glucuronidation of tanzisertib and CC-418424 revealed that, tanzisertib glucuronide was catalyzed by: UGT1A1, 1A4, 1A10 and 2B4, while CC-418424 glucuronidation was catalyzed by UGT2B4 and 2B7.

  7. Geldanamycin attenuates 3-nitropropionic acid-induced apoptosis and JNK activation through the expression of HSP 70 in striatal cells

    PubMed Central

    CHOI, YONG-JOON; KIM, NAM HO; LIM, MAN SUP; LEE, HEE JAE; KIM, SUNG SOO; CHUN, WANJOO

    2014-01-01

    Although selective striatal cell death is a characteristic hallmark in the pathogenesis of Huntington’s disease (HD), the underlying mechanism of striatal susceptibility remains to be clarified. Heat shock proteins (HSPs) have been reported to suppress the aggregate formation of mutant huntingtin and concurrent striatal cell death. In a previous study, we observed that heat shock transcription factor 1 (HSF1), a major transcription factor of HSPs, significantly attenuated 3-nitropropionic acid (3NP)-induced reactive oxygen species (ROS) production and apoptosis through the expression of HSP 70 in striatal cells. To investigate the differential roles of HSPs in 3NP-induced striatal cell death, the effect of geldanamycin (GA), an HSP 90 inhibitor, was examined in 3NP-stimulated striatal cells. GA significantly attenuated 3NP-induced striatal apoptosis and ROS production with an increased expression of HSP 70. Triptolide (TL), an HSP 70 inhibitor, abolished GA-mediated protective effects in 3NP-stimulated striatal cells. To understand the underlying mechanism by which GA-mediated HSP 70 protects striatal cells against 3NP stimulation, the involvement of various signaling pathways was examined. GA significantly attenuated 3NP-induced c-Jun N-terminal kinase (JNK) phosphorylation and subsequent c-Jun phosphorylation in striatal cells. Taken together, the present study demonstrated that GA exhibits protective properties against 3NP-induced apoptosis and JNK activation via the induction of HSP 70 in striatal cells, suggesting that expression of HSP 70 may be a valuable therapeutic target in the treatment of HD. PMID:24756698

  8. Crystal structure of human dual specificity phosphatase, JNK stimulatory phosphatase-1, at 1.5 A resolution.

    PubMed

    Yokota, Takehiro; Nara, Yukinori; Kashima, Akiko; Matsubara, Keiko; Misawa, Satoru; Kato, Ryohei; Sugio, Shigetoshi

    2007-02-01

    Human JNK stimulatory phosphatase-1 (JSP-1) is a novel member of dual specificity phosphatases. A C-terminus truncated JSP-1 was expressed in Escherichia coli and was crystallized using the sitting-drop vapor diffusion method. Thin-plate crystals obtained at 278 K belong to a monoclinic space group, C2, with unit-cell parameters a = 84.0 A, b = 49.3 A, c = 47.3 A, and beta = 119.5 degrees , and diffract up to 1.5 A resolution at 100 K. The structure of JSP-1 has a single compact (alpha/beta) domain, which consists of six alpha-helices and five beta-strands, and shows a conserved structural scaffold in regard to both DSPs and PTPs. A cleft formed by a PTP-loop at the active site is very shallow, and is occupied by one sulfonate compound, MES, at the bottom. In the binary complex structure of JSP-1 with MES, the conformations of three important segments in regard to the catalytic mechanism are not similar to those in PTP1B. JSP-1 has no loop corresponding to the Lys120-loop of PTP1B, and tryptophan residue corresponding to the substrate-stacking in PTP1B is substituted by alanine residue in JSP-1. Copyright 2006 Wiley-Liss, Inc.

  9. Sp1 is a transcription repressor to stanniocalcin-1 expression in TSA-treated human colon cancer cells, HT29.

    PubMed

    Law, Alice Y S; Yeung, B H Y; Ching, L Y; Wong, Chris K C

    2011-08-01

    Our previous study demonstrated that, stanniocalcin-1 (STC1) was a target of histone deacetylase (HDAC) inhibitors and was involved in trichostatin A (TSA) induced apoptosis in the human colon cancer cells, HT29. In this study, we reported that the transcriptional factor, specificity protein 1 (Sp1) in association with retinoblastoma (Rb) repressed STC1 gene transcription in TSA-treated HT29 cells. Our data demonstrated that, a co-treatment of the cells with TSA and Sp1 inhibitor, mithramycin A (MTM) led to a marked synergistic induction of STC1 transcript levels, STC1 promoter (1 kb)-driven luciferase activity and an increase of apoptotic cell population. The knockdown of Sp1 gene expression in TSA treated cells, revealed the repressor role of Sp1 in STC1 transcription. Using a protein phosphatase inhibitor okadaic acid (OKA), an increase of Sp1 hyperphosphorylation and so a reduction of its transcriptional activity, led to a significant induction of STC1 gene expression. Chromatin immunoprecipitation (ChIP) assay revealed that Sp1 binding on STC1 proximal promoter in TSA treated cells. The binding of Sp1 to STC1 promoter was abolished by the co-treatment of MTM or OKA in TSA-treated cells. Re-ChIP assay illustrated that Sp1-mediated inhibition of STC1 transcription was associated with the recruitment of another repressor molecule, Rb. Collectively our findings identify STC1 is a downstream target of Sp1. Copyright © 2011 Wiley-Liss, Inc.

  10. Resveratrol Ameliorates Palmitate-Induced Inflammation in Skeletal Muscle Cells by Attenuating Oxidative Stress and JNK/NF-κB Pathway in a SIRT1-Independent Mechanism.

    PubMed

    Sadeghi, Asie; Seyyed Ebrahimi, Shadi Sadat; Golestani, Abolfazl; Meshkani, Reza

    2017-09-01

    Resveratrol has been shown to exert anti-inflammatory and anti-oxidant effects in a variety of cell types, however, its role in prevention of inflammatory responses mediated by palmitate in skeletal muscle cells remains unexplored. In the present study, we investigated the effects of resveratrol on palmitate-induced inflammation and elucidated the underlying mechanisms in skeletal muscle cells. The results showed that palmitate significantly enhanced TNF-α and IL-6 mRNA expression and protein secretion from C2C12 cells at 12, 24, and 36 h treatments. Increased expression of cytokines was accompanied by an enhanced phosphorylation of JNK, P38, ERK1/2, and IKKα/IKKβ. In addition, JNK and P38 inhibitors could significantly attenuate palmitate-induced mRNA expression of TNF-α and IL-6, respectively, whereas NF-κB inhibitor reduced the expression of both cytokines in palmitate-treated cells. Resveratrol pretreatment significantly prevented palmitate-induced TNF-α and IL-6 mRNA expression and protein secretion in C2C12 cells. Importantly, pre-treatment of the cells with resveratrol completely abrogated the phosphorylation of ERK1/2, JNK, and IKKα/IKKβ in palmitate treated cells. The protection from palmitate-induced inflammation by resveratrol was accompanied by a decrease in the generation of reactive oxygen species (ROS). N-acetyl cysteine (NAC), a known scavenger of ROS, could protect palmitate-induced expression of TNF-α and IL-6. Furthermore, inhibition of SIRT1 by shRNA or sirtinol demonstrated that the anti-inflammatory effect of resveratrol in muscle cells is mediated through a SIRT1-independent mechanism. Taken together, these findings suggest that resveratrol may represent a promising therapy for prevention of inflammation in skeletal muscle cells. J. Cell. Biochem. 118: 2654-2663, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. Drosophila myeloid leukemia factor acts with DREF to activate the JNK signaling pathway

    PubMed Central

    Yanai, H; Yoshioka, Y; Yoshida, H; Nakao, Y; Plessis, A; Yamaguchi, M

    2014-01-01

    Drosophila myelodysplasia/myeloid leukemia factor (dMLF), a homolog of human MLF1, oncogene was first identified by yeast two-hybrid screen using the DNA replication-related element-binding factor (DREF) as bait. DREF is a transcription factor that regulates proliferation-related genes in Drosophila. It is known that overexpression of dMLF in the wing imaginal discs through the engrailed-GAL4 driver causes an atrophied wing phenotype associated with the induction of apoptosis. However, the precise mechanisms involved have yet to be clarified. Here, we found the atrophied phenotype to be suppressed by loss-of-function mutation of Drosophila Jun N-terminal kinase (JNK), basket (bsk). Overexpression of dMLF induced ectopic JNK activation in the wing disc monitored with the puckered-lacZ reporter line, resulting in induction of apoptosis. The DREF-binding consensus DRE sequence could be shown to exist in the bsk promoter. Chromatin immunoprecipitation assays in S2 cells with anti-dMLF IgG and quantitative real-time PCR revealed that dMLF binds specifically to the bsk promoter region containing the DRE sequence. Furthermore, using a transient luciferase expression assay, we provide evidence that knockdown of dMLF reduced bsk gene promoter activity in S2 cells. Finally, we show that dMLF interacts with DREF in vivo. Altogether, these data indicate that dMLF acts with DREF to stimulate the bsk promoter and consequently activates the JNK pathway to promote apoptosis. PMID:24752236

  12. Drosophila myeloid leukemia factor acts with DREF to activate the JNK signaling pathway.

    PubMed

    Yanai, H; Yoshioka, Y; Yoshida, H; Nakao, Y; Plessis, A; Yamaguchi, M

    2014-04-21

    Drosophila myelodysplasia/myeloid leukemia factor (dMLF), a homolog of human MLF1, oncogene was first identified by yeast two-hybrid screen using the DNA replication-related element-binding factor (DREF) as bait. DREF is a transcription factor that regulates proliferation-related genes in Drosophila. It is known that overexpression of dMLF in the wing imaginal discs through the engrailed-GAL4 driver causes an atrophied wing phenotype associated with the induction of apoptosis. However, the precise mechanisms involved have yet to be clarified. Here, we found the atrophied phenotype to be suppressed by loss-of-function mutation of Drosophila Jun N-terminal kinase (JNK), basket (bsk). Overexpression of dMLF induced ectopic JNK activation in the wing disc monitored with the puckered-lacZ reporter line, resulting in induction of apoptosis. The DREF-binding consensus DRE sequence could be shown to exist in the bsk promoter. Chromatin immunoprecipitation assays in S2 cells with anti-dMLF IgG and quantitative real-time PCR revealed that dMLF binds specifically to the bsk promoter region containing the DRE sequence. Furthermore, using a transient luciferase expression assay, we provide evidence that knockdown of dMLF reduced bsk gene promoter activity in S2 cells. Finally, we show that dMLF interacts with DREF in vivo. Altogether, these data indicate that dMLF acts with DREF to stimulate the bsk promoter and consequently activates the JNK pathway to promote apoptosis.

  13. JNK-Interacting Protein 3 Mediates the Retrograde Transport of Activated c-Jun N-Terminal Kinase and Lysosomes

    PubMed Central

    Drerup, Catherine M.; Nechiporuk, Alex V.

    2013-01-01

    Retrograde axonal transport requires an intricate interaction between the dynein motor and its cargo. What mediates this interaction is largely unknown. Using forward genetics and a novel in vivo imaging approach, we identified JNK-interacting protein 3 (Jip3) as a direct mediator of dynein-based retrograde transport of activated (phosphorylated) c-Jun N-terminal Kinase (JNK) and lysosomes. Zebrafish jip3 mutants (jip3nl7) displayed large axon terminal swellings that contained high levels of activated JNK and lysosomes, but not other retrograde cargos such as late endosomes and autophagosomes. Using in vivo analysis of axonal transport, we demonstrated that the terminal accumulations of activated JNK and lysosomes were due to a decreased frequency of retrograde movement of these cargos in jip3nl7, whereas anterograde transport was largely unaffected. Through rescue experiments with Jip3 engineered to lack the JNK binding domain and exogenous expression of constitutively active JNK, we further showed that loss of Jip3–JNK interaction underlies deficits in pJNK retrograde transport, which subsequently caused axon terminal swellings but not lysosome accumulation. Lysosome accumulation, rather, resulted from loss of lysosome association with dynein light intermediate chain (dynein accessory protein) in jip3nl7, as demonstrated by our co-transport analyses. Thus, our results demonstrate that Jip3 is necessary for the retrograde transport of two distinct cargos, active JNK and lysosomes. Furthermore, our data provide strong evidence that Jip3 in fact serves as an adapter protein linking these cargos to dynein. PMID:23468645

  14. bFGF Regulates PI3-Kinase-Rac1-JNK Pathway and Promotes Fibroblast Migration in Wound Healing

    PubMed Central

    Kanazawa, Shigeyuki; Fujiwara, Toshihiro; Matsuzaki, Shinsuke; Shingaki, Kenta; Taniguchi, Manabu; Miyata, Shingo; Tohyama, Masaya; Sakai, Yasuo; Yano, Kenji; Hosokawa, Ko; Kubo, Tateki

    2010-01-01

    Fibroblast proliferation and migration play important roles in wound healing. bFGF is known to promote both fibroblast proliferation and migration during the process of wound healing. However, the signal transduction of bFGF-induced fibroblast migration is still unclear, because bFGF can affect both proliferation and migration. Herein, we investigated the effect of bFGF on fibroblast migration regardless of its effect on fibroblast proliferation. We noticed involvement of the small GTPases of the Rho family, PI3-kinase, and JNK. bFGF activated RhoA, Rac1, PI3-kinase, and JNK in cultured fibroblasts. Inhibition of RhoA did not block bFGF-induced fibroblast migration, whereas inhibition of Rac1, PI3-kinase, or JNK blocked the fibroblast migration significantly. PI3-kinase-inhibited cells down-regulated the activities of Rac1 and JNK, and Rac1-inhibited cells down-regulated JNK activity, suggesting that PI3-kinase is upstream of Rac1 and that JNK is downstream of Rac1. Thus, we concluded that PI3-kinase, Rac1, and JNK were essential for bFGF-induced fibroblast migration, which is a novel pathway of bFGF-induced cell migration. PMID:20808927

  15. MKP-7, a JNK phosphatase, blocks ERK-dependent gene activation by anchoring phosphorylated ERK in the cytoplasm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Masuda, Kouhei; Katagiri, Chiaki; Division of Biochemical Oncology and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo

    2010-03-05

    MAPK phosphatase-7 (MKP-7) was identified as a JNK-specific phosphatase. However, despite its high specificity for JNK, MKP-7 interacts also with ERK. We previously showed that as a physiological consequence of their interaction, activated ERK phosphorylates MKP-7 at Ser-446, and stabilizing MKP-7. In the present study, we analyzed MKP-7 function in activation of ERK. A time-course experiment showed that both MKP-7 and its phosphatase-dead mutant prolonged mitogen-induced ERK phosphorylation, suggesting that MKP-7 functions as a scaffold for ERK. An important immunohistological finding was that nuclear translocation of phospho-ERK following PMA stimulation was blocked by co-expressed MKP-7 and, moreover, that phospho-ERK co-localizedmore » with MKP-7 in the cytoplasm. Reporter gene analysis indicated that MKP-7 blocks ERK-mediated transcription. Overall, our data indicate that MKP-7 down-regulates ERK-dependent gene expression by blocking nuclear accumulation of phospho-ERK.« less

  16. Geldanamycin attenuates 3‑nitropropionic acid‑induced apoptosis and JNK activation through the expression of HSP 70 in striatal cells.

    PubMed

    Choi, Yong-Joon; Kim, Nam Ho; Lim, Man Sup; Lee, Hee Jae; Kim, Sung Soo; Chun, Wanjoo

    2014-07-01

    Although selective striatal cell death is a characteristic hallmark in the pathogenesis of Huntington's disease (HD), the underlying mechanism of striatal susceptibility remains to be clarified. Heat shock proteins (HSPs) have been reported to suppress the aggregate formation of mutant huntingtin and concurrent striatal cell death. In a previous study, we observed that heat shock transcription factor 1 (HSF1), a major transcription factor of HSPs, significantly attenuated 3‑nitropropionic acid (3NP)‑induced reactive oxygen species (ROS) production and apoptosis through the expression of HSP 70 in striatal cells. To investigate the differential roles of HSPs in 3NP‑induced striatal cell death, the effect of geldanamycin (GA), an HSP 90 inhibitor, was examined in 3NP‑stimulated striatal cells. GA significantly attenuated 3NP‑induced striatal apoptosis and ROS production with an increased expression of HSP 70. Triptolide (TL), an HSP 70 inhibitor, abolished GA‑mediated protective effects in 3NP‑stimulated striatal cells. To understand the underlying mechanism by which GA‑mediated HSP 70 protects striatal cells against 3NP stimulation, the involvement of various signaling pathways was examined. GA significantly attenuated 3NP‑induced c‑Jun N‑terminal kinase (JNK) phosphorylation and subsequent c‑Jun phosphorylation in striatal cells. Taken together, the present study demonstrated that GA exhibits protective properties against 3NP‑induced apoptosis and JNK activation via the induction of HSP 70 in striatal cells, suggesting that expression of HSP 70 may be a valuable therapeutic target in the treatment of HD.

  17. Propofol protects hippocampal neurons from apoptosis in ischemic brain injury by increasing GLT-1 expression and inhibiting the activation of NMDAR via the JNK/Akt signaling pathway.

    PubMed

    Gong, Hong-Yan; Zheng, Fang; Zhang, Chao; Chen, Xi-Yan; Liu, Jing-Jing; Yue, Xiu-Qin

    2016-09-01

    Ischemic brain injury (IBI) can cause nerve injury and is a leading cause of morbidity and mortality worldwide. The neuroprotective effects of propofol against IBI have been previously demonstrated. However, the neuroprotective effects of propofol on hippocampal neurons are not yet entirely clear. In the present study, models of IBI were established in hypoxia-exposed hippocampal neuronal cells. Cell viability assay and apoptosis assay were performed to examine the neuroprotective effects of propofol on hippocampal neurons in IBI. A significant decrease in cell viability and a significant increase in cell apoptosis were observed in the IBI group compared with the control group, accompanied by a decrease in glial glutamate transporter-1 (GLT‑1) expression as determined by RT-qPCR and western blot analysis. The effects of IBI were reversed by propofol treatment. The siRNA-mediated knockdown of GLT‑1 in the hypoxia-exposed hippocampal neuronal cells led to an increase in cell apoptosis, Jun N-terminal kinase (JNK) activation and N-methyl-D‑aspartate (NMDA) receptor (NR1 and NR2B) activation, as well as to a decrease in cell viability and a decrease in Akt activation. The effects of RNA interference-mediated GLT‑1 gene silencing on cell viability, JNK activation, NMDAR activation, cell apoptosis and Akt activation in the hippocampal neuronal cells were slightly reversed by propofol treatment. The JNK agonist, anisomycin, and the Akt inhibitor, LY294002, both significantly blocked the effects of propofol on hippocampal neuronal cell viability and apoptosis in IBI. The decrease in JNK activation and the increase in Akt activation caused by GLT‑1 overexpression were reversed by NMDA. Collectively, our findings suggest that propofol treatment protects hippocampal neurons against IBI by enhancing GLT‑1 expression and inhibiting the activation of NMDAR via the JNK/Akt signaling pathway.

  18. The Inhibitor Ko143 Is Not Specific for ABCG2.

    PubMed

    Weidner, Lora D; Zoghbi, Sami S; Lu, Shuiyu; Shukla, Suneet; Ambudkar, Suresh V; Pike, Victor W; Mulder, Jan; Gottesman, Michael M; Innis, Robert B; Hall, Matthew D

    2015-09-01

    Imaging ATP-binding cassette (ABC) transporter activity in vivo with positron emission tomography requires both a substrate and a transporter inhibitor. However, for ABCG2, there is no inhibitor proven to be specific to that transporter alone at the blood-brain barrier. Ko143 [[(3S,6S,12aS)-1,2,3,4,6,7,12,12a-octahydro-9-methoxy-6-(2-methylpropyl)-1,4-dioxopyrazino[1',2':1,6]pyrido[3,4- b]indole-3-propanoic acid 1,1-dimethylethyl ester], a nontoxic analog of fungal toxin fumitremorgin C, is a potent inhibitor of ABCG2, although its specificity in mouse and human systems is unclear. This study examined the selectivity of Ko143 using human embryonic kidney cell lines transfected with ABCG2, ABCB1, or ABCC1 in several in vitro assays. The stability of Ko143 in rat plasma was measured using high performance liquid chromatography. Our results show that, in addition to being a potent inhibitor of ABCG2, at higher concentrations (≥1 μM) Ko143 also has an effect on the transport activity of both ABCB1 and ABCC1. Furthermore, Ko143 was found to be unstable in rat plasma. These findings indicate that Ko143 lacks specificity for ABCG2 and this should be taken into consideration when using Ko143 for both in vitro and in vivo experiments. U.S. Government work not protected by U.S. copyright.

  19. Mu opioid receptor stimulation activates c-Jun N-terminal kinase 2 by distinct arrestin-dependent and independent mechanisms.

    PubMed

    Kuhar, Jamie Rose; Bedini, Andrea; Melief, Erica J; Chiu, Yen-Chen; Striegel, Heather N; Chavkin, Charles

    2015-09-01

    G protein-coupled receptor desensitization is typically mediated by receptor phosphorylation by G protein-coupled receptor kinase (GRK) and subsequent arrestin binding; morphine, however, was previously found to activate a c-Jun N-terminal kinase (JNK)-dependent, GRK/arrestin-independent pathway to produce mu opioid receptor (MOR) inactivation in spinally-mediated, acute anti-nociceptive responses [Melief et al.] [1]. In the current study, we determined that JNK2 was also required for centrally-mediated analgesic tolerance to morphine using the hotplate assay. We compared JNK activation by morphine and fentanyl in JNK1(-/-), JNK2(-/-), JNK3(-/-), and GRK3(-/-) mice and found that both compounds specifically activate JNK2 in vivo; however, fentanyl activation of JNK2 was GRK3-dependent, whereas morphine activation of JNK2 was GRK3-independent. In MOR-GFP expressing HEK293 cells, treatment with either arrestin siRNA, the Src family kinase inhibitor PP2, or the protein kinase C (PKC) inhibitor Gö6976 indicated that morphine activated JNK2 through an arrestin-independent Src- and PKC-dependent mechanism, whereas fentanyl activated JNK2 through a Src-GRK3/arrestin-2-dependent and PKC-independent mechanism. This study resolves distinct ligand-directed mechanisms of JNK activation by mu opioid agonists and understanding ligand-directed signaling at MOR may improve opioid therapeutics. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Erabulenols, inhibitors of cholesteryl ester transfer protein produced by Penicillium sp. FO-5637. I.Production, isolation and biological properties.

    PubMed

    Tomoda, H; Tabata, N; Masuma, R; Si, S Y; Omura, S

    1998-07-01

    Penicillium sp. FO-5637, a soil isolate, was found to produce a series of inhibitors of cholesteryl ester transfer protein (CETP). Novel active compounds, designated erabulenols A and B, were isolated from the fermentation broth of the producing strain by solvent extraction, ODS column chromatography and HPLC. Erabulenols A and B inhibit human CETP activity with IC50 values of 47.7 and 58.2 microM in an in vitro assay system containing 200 microM BSA, respectively.

  1. Phosphorylation of Glutathione S-Transferase P1 (GSTP1) by Epidermal Growth Factor Receptor (EGFR) Promotes Formation of the GSTP1-c-Jun N-terminal kinase (JNK) Complex and Suppresses JNK Downstream Signaling and Apoptosis in Brain Tumor Cells*

    PubMed Central

    Okamura, Tatsunori; Antoun, Gamil; Keir, Stephen T.; Friedman, Henry; Bigner, Darell D.; Ali-Osman, Francis

    2015-01-01

    Under normal physiologic conditions, the glutathione S-transferase P1 (GSTP1) protein exists intracellularly as a dimer in reversible equilibrium with its monomeric subunits. In the latter form, GSTP1 binds to the mitogen-activated protein kinase, JNK, and inhibits JNK downstream signaling. In tumor cells, which frequently are characterized by constitutively high GSTP1 expression, GSTP1 undergoes phosphorylation by epidermal growth factor receptor (EGFR) at tyrosine residues 3, 7, and 198. Here we report on the effect of this EGFR-dependent GSTP1 tyrosine phosphorylation on the interaction of GSTP1 with JNK, on the regulation of JNK downstream signaling by GSTP1, and on tumor cell survival. Using in vitro and in vivo growing human brain tumors, we show that tyrosine phosphorylation shifts the GSTP1 dimer-monomer equilibrium to the monomeric state and facilitates the formation of the GSTP1-JNK complex, in which JNK is functionally inhibited. Targeted mutagenesis and functional analysis demonstrated that the increased GSTP1 binding to JNK results from phosphorylation of the GSTP1 C-terminal Tyr-198 by EGFR and is associated with a >2.5-fold decrease in JNK downstream signaling and a significant suppression of both spontaneous and drug-induced apoptosis in the tumor cells. The findings define a novel mechanism of regulatory control of JNK signaling that is mediated by the EGFR/GSTP1 cross-talk and provides a survival advantage for tumors with activated EGFR and high GSTP1 expression. The results lay the foundation for a novel strategy of dual EGFR/GSTP1 for treating EGFR+ve, GSTP1 expressing GBMs. PMID:26429914

  2. Phosphorylation of Glutathione S-Transferase P1 (GSTP1) by Epidermal Growth Factor Receptor (EGFR) Promotes Formation of the GSTP1-c-Jun N-terminal kinase (JNK) Complex and Suppresses JNK Downstream Signaling and Apoptosis in Brain Tumor Cells.

    PubMed

    Okamura, Tatsunori; Antoun, Gamil; Keir, Stephen T; Friedman, Henry; Bigner, Darell D; Ali-Osman, Francis

    2015-12-25

    Under normal physiologic conditions, the glutathione S-transferase P1 (GSTP1) protein exists intracellularly as a dimer in reversible equilibrium with its monomeric subunits. In the latter form, GSTP1 binds to the mitogen-activated protein kinase, JNK, and inhibits JNK downstream signaling. In tumor cells, which frequently are characterized by constitutively high GSTP1 expression, GSTP1 undergoes phosphorylation by epidermal growth factor receptor (EGFR) at tyrosine residues 3, 7, and 198. Here we report on the effect of this EGFR-dependent GSTP1 tyrosine phosphorylation on the interaction of GSTP1 with JNK, on the regulation of JNK downstream signaling by GSTP1, and on tumor cell survival. Using in vitro and in vivo growing human brain tumors, we show that tyrosine phosphorylation shifts the GSTP1 dimer-monomer equilibrium to the monomeric state and facilitates the formation of the GSTP1-JNK complex, in which JNK is functionally inhibited. Targeted mutagenesis and functional analysis demonstrated that the increased GSTP1 binding to JNK results from phosphorylation of the GSTP1 C-terminal Tyr-198 by EGFR and is associated with a >2.5-fold decrease in JNK downstream signaling and a significant suppression of both spontaneous and drug-induced apoptosis in the tumor cells. The findings define a novel mechanism of regulatory control of JNK signaling that is mediated by the EGFR/GSTP1 cross-talk and provides a survival advantage for tumors with activated EGFR and high GSTP1 expression. The results lay the foundation for a novel strategy of dual EGFR/GSTP1 for treating EGFR+ve, GSTP1 expressing GBMs. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. A novel dual NO-donating oxime and c-Jun N-terminal kinase inhibitor protects against cerebral ischemia-reperfusion injury in mice.

    PubMed

    Atochin, Dmitriy N; Schepetkin, Igor A; Khlebnikov, Andrei I; Seledtsov, Victor I; Swanson, Helen; Quinn, Mark T; Huang, Paul L

    2016-04-08

    The c-Jun N-terminal kinase (JNK) has been shown to be an important regulator of neuronal cell death. Previously, we synthesized the sodium salt of 11H-indeno[1,2-b]quinoxalin-11-one (IQ-1S) and demonstrated that it was a high-affinity inhibitor of the JNK family. In the present work, we found that IQ-1S could release nitric oxide (NO) during its enzymatic metabolism by liver microsomes. Moreover, serum nitrite/nitrate concentration in mice increased after intraperitoneal injection of IQ-1S. Because of these dual actions as JNK inhibitor and NO-donor, the therapeutic potential of IQ-1S was evaluated in an animal stroke model. We subjected wild-type C57BL6 mice to focal ischemia (30min) with subsequent reperfusion (48h). Mice were treated with IQ-1S (25mg/kg) suspended in 10% solutol or with vehicle alone 30min before and 24h after middle cerebral artery (MCA) occlusion (MCAO). Using laser-Doppler flowmetry, we monitored cerebral blood flow (CBF) above the MCA during 30min of MCAO provoked by a filament and during the first 30min of subsequent reperfusion. In mice treated with IQ-1S, ischemic and reperfusion values of CBF were not different from vehicle-treated mice. However, IQ-1S treated mice demonstrated markedly reduced neurological deficit and infarct volumes as compared with vehicle-treated mice after 48h of reperfusion. Our results indicate that the novel JNK inhibitor releases NO during its oxidoreductive bioconversion and improves stroke outcome in a mouse model of cerebral reperfusion. We conclude that IQ-1S is a promising dual functional agent for the treatment of cerebral ischemia and reperfusion injury. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. A Novel Dual NO-donating Oxime and c-Jun N-terminal Kinase Inhibitor Protects Against Cerebral Ischemia–Reperfusion Injury in Mice

    PubMed Central

    Atochin, Dmitriy N.; Schepetkin, Igor A.; Khlebnikov, Andrei I.; Seledtsov, Victor I.; Swanson, Helen; Quinn, Mark T.; Huang, Paul L.

    2017-01-01

    The c-Jun N-terminal kinase (JNK) has been shown to be an important regulator of neuronal cell death. Previously, we synthesized the sodium salt of 11H-indeno[1,2-b]quinoxalin-11-one (IQ-1S) and demonstrated that it was a high-affinity inhibitor of the JNK family. In the present work, we found that IQ-1S could release nitric oxide (NO) during its enzymatic metabolism by liver microsomes. Moreover, serum nitrite/nitrate concentration in mice increased after intraperitoneal injection of IQ-1S. Because of these dual actions as JNK inhibitor and NO-donor, the therapeutic potential of IQ-1S was evaluated in an animal stroke model. We subjected wild-type C57BL6 mice to focal ischemia (30 minutes) with subsequent reperfusion (48 hours). Mice were treated with IQ-1S (25 mg/kg) suspended in 10% solutol or with vehicle alone 30 minutes before and 24 hours after middle cerebral artery MCA) occlusion (MCAO). Using laser-Doppler flowmetry, we monitored cerebral blood flow (CBF) above the MCA during 30 minutes of MCAO provoked by a filament and during the first 30 minutes of subsequent reperfusion. In mice treated with IQ-1S, ischemic and reperfusion values of CBF were not different from vehicle-treated mice. However, IQ-1S treated mice demonstrated markedly reduced neurological deficit and infarct volumes as compared with vehicle-treated mice after 48 hours of reperfusion. Our results indicate that the novel JNK inhibitor releases NO during its oxidoreductive bioconversion and improves stroke outcome in a mouse model of cerebral reperfusion. We conclude that IQ-1S is a promising dual functional agent for the treatment of cerebral ischemia and reperfusion injury. PMID:26923672

  5. JNK1 inhibition by Licochalcone A leads to neuronal protection against excitotoxic insults derived of kainic acid.

    PubMed

    Busquets, Oriol; Ettcheto, Miren; Verdaguer, Ester; Castro-Torres, Ruben D; Auladell, Carme; Beas-Zarate, Carlos; Folch, Jaume; Camins, Antoni

    2018-03-15

    The mitogen-activated protein kinase family (MAPK) is an important group of enzymes involved in cellular responses to diverse external stimuli. One of the members of this family is the c-Jun-N-terminal kinase (JNK). The activation of the JNK pathway has been largely associated with the pathogenesis that occurs in epilepsy and neurodegeneration. Kainic acid (KA) administration in rodents is an experimental approach that induces status epilepticus (SE) and replicates many of the phenomenological features of human temporal lobe epilepsy (TLE). Recent studies in our group have evidenced that the absence of the JNK1 gene has neuroprotective effects against the damage induced by KA, as it occurs with the absence of JNK3. The aim of the present study was to analyse whether the pharmacological inhibition of JNK1 by Licochalcone A (Lic-A) had similar effects and if it may be considered as a new molecule for the treatment of SE. In order to achieve this objective, animals were pre-treated with Lic-A and posteriorly administered with KA as a model for TLE. In addition, a comparative study with KA was performed between wild type pre-treated with Lic-A and single knock-out transgenic mice for the Jnk1 -/- gene. Our results showed that JNK1 inhibition by Lic-A, previous to KA administration, caused a reduction in the convulsive pattern. Furthermore, it reduced phosphorylation levels of the JNK, as well as its activity. In addition, Lic-A prevented hippocampal neuronal degeneration, increased pro-survival anti-apoptotic mechanisms, reduced pro-apoptotic biomarkers, decreased cellular stress and neuroinflammatory processes. Thus, our results suggest that inhibition of the JNK1 by Lic-A has neuroprotective effects and that; it could be a new potential approach for the treatment of SE and neurodegeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Sclerosis

    DTIC Science & Technology

    2014-10-01

    AWARD NUMBER: W81XWH-12-1-0431 TITLE: “c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Sclerosis ” PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE “c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Scelerosis” 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH

  7. Synthesis and evaluation of phosphorus containing, specific CDK9/CycT1 inhibitors.

    PubMed

    Németh, Gábor; Greff, Zoltán; Sipos, Anna; Varga, Zoltán; Székely, Rita; Sebestyén, Mónika; Jászay, Zsuzsa; Béni, Szabolcs; Nemes, Zoltán; Pirat, Jean-Luc; Volle, Jean-Noël; Virieux, David; Gyuris, Ágnes; Kelemenics, Katalin; Ay, Eva; Minarovits, Janos; Szathmary, Susan; Kéri, György; Orfi, László

    2014-05-22

    Although there is a significant effort in the design of a selective CDK9/CycT1 inhibitor, no compound has been proven to be a specific inhibitor of this kinase so far. The aim of this research was to develop novel and selective phosphorus containing CDK9/CycT1 inhibitors. Molecules bearing phosphonamidate, phosphonate, and phosphinate moieties were synthesized. Prepared compounds were evaluated in an enzymatic CDK9/CycT1 assay. The most potent molecules were tested in cell-based toxicity and HIV proliferation assays. Selectivity of shortlisted compounds against CDKs and other kinases was tested. The best compound was shown to be a highly specific, ATP-competitive inhibitor of CDK9/CycT1 with antiviral activity.

  8. Functions for fission yeast splicing factors SpSlu7 and SpPrp18 in alternative splice-site choice and stress-specific regulated splicing.

    PubMed

    Melangath, Geetha; Sen, Titash; Kumar, Rakesh; Bawa, Pushpinder; Srinivasan, Subha; Vijayraghavan, Usha

    2017-01-01

    Budding yeast spliceosomal factors ScSlu7 and ScPrp18 interact and mediate intron 3'ss choice during second step pre-mRNA splicing. The fission yeast genome with abundant multi-intronic transcripts, degenerate splice signals and SR proteins is an apt unicellular fungal model to deduce roles for core spliceosomal factors in alternative splice-site choice, intron retention and to study the cellular implications of regulated splicing. From our custom microarray data we deduce a stringent reproducible subset of S. pombe alternative events. We examined the role of factors SpSlu7 or SpPrp18 for these splice events and investigated the relationship to growth phase and stress. Wild-type log and stationary phase cells showed ats1+ exon 3 skipped and intron 3 retained transcripts. Interestingly the non-consensus 5'ss in ats1+ intron 3 caused SpSlu7 and SpPrp18 dependent intron retention. We validated the use of an alternative 5'ss in dtd1+ intron 1 and of an upstream alternative 3'ss in DUF3074 intron 1. The dtd1+ intron 1 non-canonical 5'ss yielded an alternative mRNA whose levels increased in stationary phase. Utilization of dtd1+ intron 1 sub-optimal 5' ss required functional SpPrp18 and SpSlu7 while compromise in SpSlu7 function alone hampered the selection of the DUF3074 intron 1 non canonical 3'ss. We analysed the relative abundance of these splice isoforms during mild thermal, oxidative and heavy metal stress and found stress-specific splice patterns for ats1+ and DUF3074 intron 1 some of which were SpSlu7 and SpPrp18 dependent. By studying ats1+ splice isoforms during compromised transcription elongation rates in wild-type, spslu7-2 and spprp18-5 mutant cells we found dynamic and intron context-specific effects in splice-site choice. Our work thus shows the combinatorial effects of splice site strength, core splicing factor functions and transcription elongation kinetics to dictate alternative splice patterns which in turn serve as an additional recourse of gene

  9. Functions for fission yeast splicing factors SpSlu7 and SpPrp18 in alternative splice-site choice and stress-specific regulated splicing

    PubMed Central

    Kumar, Rakesh; Bawa, Pushpinder; Srinivasan, Subha

    2017-01-01

    Budding yeast spliceosomal factors ScSlu7 and ScPrp18 interact and mediate intron 3’ss choice during second step pre-mRNA splicing. The fission yeast genome with abundant multi-intronic transcripts, degenerate splice signals and SR proteins is an apt unicellular fungal model to deduce roles for core spliceosomal factors in alternative splice-site choice, intron retention and to study the cellular implications of regulated splicing. From our custom microarray data we deduce a stringent reproducible subset of S. pombe alternative events. We examined the role of factors SpSlu7 or SpPrp18 for these splice events and investigated the relationship to growth phase and stress. Wild-type log and stationary phase cells showed ats1+ exon 3 skipped and intron 3 retained transcripts. Interestingly the non-consensus 5’ss in ats1+ intron 3 caused SpSlu7 and SpPrp18 dependent intron retention. We validated the use of an alternative 5’ss in dtd1+ intron 1 and of an upstream alternative 3’ss in DUF3074 intron 1. The dtd1+ intron 1 non-canonical 5’ss yielded an alternative mRNA whose levels increased in stationary phase. Utilization of dtd1+ intron 1 sub-optimal 5’ ss required functional SpPrp18 and SpSlu7 while compromise in SpSlu7 function alone hampered the selection of the DUF3074 intron 1 non canonical 3’ss. We analysed the relative abundance of these splice isoforms during mild thermal, oxidative and heavy metal stress and found stress-specific splice patterns for ats1+ and DUF3074 intron 1 some of which were SpSlu7 and SpPrp18 dependent. By studying ats1+ splice isoforms during compromised transcription elongation rates in wild-type, spslu7-2 and spprp18-5 mutant cells we found dynamic and intron context-specific effects in splice-site choice. Our work thus shows the combinatorial effects of splice site strength, core splicing factor functions and transcription elongation kinetics to dictate alternative splice patterns which in turn serve as an additional

  10. Sirtuin 3 enhanced drug sensitivity of human hepatoma cells through glutathione S-transferase pi 1/JNK signaling pathway

    PubMed Central

    Cai, Xue-Fei; Zhang, Wen-Lu; Ren, Ji-Hua; Zhou, Li; Chen, Xiang; Chen, Ke; Li, Wan-Yu; Liu, Bo; Yang, Qiu-Xia; Cheng, Sheng-Tao; Huang, Li-Xia; Huang, Ai-Long; Chen, Juan

    2016-01-01

    SIRT3, a class III histone deacetylase, has been implicated in various cancers as a novel therapeutic target. In hepatocellular carcinoma (HCC), we previously reported that SIRT3 induced cell apoptosis by regulating GSK-3β/Bax signaling pathway. Downregulation of SIRT3 in HCC cells facilitates tumor cell survival. In this study, we found that chemotherapeutic agents (doxorubicin, cisplatin and epirubicin) and sorafenib treatment downregulated SIRT3 mRNA and protein levels in three HCC cell lines. MTS assay found that SIRT3 overexpression sensitized liver cancer cells to chemotherapeutic agents and sorafenib in SMMC-7721, Huh-7 and PLC/PRF/5 cell lines. Moreover, SIRT3 overexpression promoted chemotherapeutic agents-induced or sorafenib-induced apoptosis as evidenced by flow cytometry, enhanced PARP cleavage and enhanced Caspase-9 cleavage in three HCC cells. In contrast, SIRT3 silencing increased drug resistance of HCC cells to chemotherapeutic agents. Mechanistic study found that SIRT3 downregulated the mRNA and protein levels of glutathione S-transferase pi 1 (GSTP1), which is a member of phase II detoxification enzymes families involved in metabolizing for chemotherapeutic agents. Moreover, SIRT3 decreased the amount of GSTP1 that was associated with JNK, which finally contributed the activation of JNK activity and activation of downstream target c-Jun and Bim. Importantly, GSTP1 overexpression or JNK inhibitor abolished SIRT3-induced apoptosis in HCC cells exposed to chemotherapeutic agents. Finally, there was a negative correlation between SIRT3 expression and GSTP1 expression in human HCC tissues. Together, our findings revealed SIRT3 could enhance the drug sensitivity of HCC cells to an array of chemotherapeutic agents. SIRT3 may serve as a potential target for improving the chemosensitivity of HCC patients. PMID:27367026

  11. Sirtuin 3 enhanced drug sensitivity of human hepatoma cells through glutathione S-transferase pi 1/JNK signaling pathway.

    PubMed

    Tao, Na-Na; Zhou, Hong-Zhong; Tang, Hua; Cai, Xue-Fei; Zhang, Wen-Lu; Ren, Ji-Hua; Zhou, Li; Chen, Xiang; Chen, Ke; Li, Wan-Yu; Liu, Bo; Yang, Qiu-Xia; Cheng, Sheng-Tao; Huang, Li-Xia; Huang, Ai-Long; Chen, Juan

    2016-08-02

    SIRT3, a class III histone deacetylase, has been implicated in various cancers as a novel therapeutic target. In hepatocellular carcinoma (HCC), we previously reported that SIRT3 induced cell apoptosis by regulating GSK-3β/Bax signaling pathway. Downregulation of SIRT3 in HCC cells facilitates tumor cell survival. In this study, we found that chemotherapeutic agents (doxorubicin, cisplatin and epirubicin) and sorafenib treatment downregulated SIRT3 mRNA and protein levels in three HCC cell lines. MTS assay found that SIRT3 overexpression sensitized liver cancer cells to chemotherapeutic agents and sorafenib in SMMC-7721, Huh-7 and PLC/PRF/5 cell lines. Moreover, SIRT3 overexpression promoted chemotherapeutic agents-induced or sorafenib-induced apoptosis as evidenced by flow cytometry, enhanced PARP cleavage and enhanced Caspase-9 cleavage in three HCC cells. In contrast, SIRT3 silencing increased drug resistance of HCC cells to chemotherapeutic agents. Mechanistic study found that SIRT3 downregulated the mRNA and protein levels of glutathione S-transferase pi 1 (GSTP1), which is a member of phase II detoxification enzymes families involved in metabolizing for chemotherapeutic agents. Moreover, SIRT3 decreased the amount of GSTP1 that was associated with JNK, which finally contributed the activation of JNK activity and activation of downstream target c-Jun and Bim. Importantly, GSTP1 overexpression or JNK inhibitor abolished SIRT3-induced apoptosis in HCC cells exposed to chemotherapeutic agents. Finally, there was a negative correlation between SIRT3 expression and GSTP1 expression in human HCC tissues. Together, our findings revealed SIRT3 could enhance the drug sensitivity of HCC cells to an array of chemotherapeutic agents. SIRT3 may serve as a potential target for improving the chemosensitivity of HCC patients.

  12. Aminopyridine-based c-Jun N-terminal kinase inhibitors with cellular activity and minimal cross-kinase activity.

    PubMed

    Szczepankiewicz, Bruce G; Kosogof, Christi; Nelson, Lissa T J; Liu, Gang; Liu, Bo; Zhao, Hongyu; Serby, Michael D; Xin, Zhili; Liu, Mei; Gum, Rebecca J; Haasch, Deanna L; Wang, Sanyi; Clampit, Jill E; Johnson, Eric F; Lubben, Thomas H; Stashko, Michael A; Olejniczak, Edward T; Sun, Chaohong; Dorwin, Sarah A; Haskins, Kristi; Abad-Zapatero, Cele; Fry, Elizabeth H; Hutchins, Charles W; Sham, Hing L; Rondinone, Cristina M; Trevillyan, James M

    2006-06-15

    The c-Jun N-terminal kinases (JNK-1, -2, and -3) are members of the mitogen activated protein (MAP) kinase family of enzymes. They are activated in response to certain cytokines, as well as by cellular stresses including chemotoxins, peroxides, and irradiation. They have been implicated in the pathology of a variety of different diseases with an inflammatory component including asthma, stroke, Alzheimer's disease, and type 2 diabetes mellitus. In this work, high-throughput screening identified a JNK inhibitor with an excellent kinase selectivity profile. Using X-ray crystallography and biochemical screening to guide our lead optimization, we prepared compounds with inhibitory potencies in the low-double-digit nanomolar range, activity in whole cells, and pharmacokinetics suitable for in vivo use. The new compounds were over 1,000-fold selective for JNK-1 and -2 over other MAP kinases including ERK2, p38alpha, and p38delta and showed little inhibitory activity against a panel of 74 kinases.

  13. Structure-Activity Relationships of the Human Immunodeficiency Virus Type 1 Maturation Inhibitor PF-46396.

    PubMed

    Murgatroyd, Christopher; Pirrie, Lisa; Tran, Fanny; Smith, Terry K; Westwood, Nicholas J; Adamson, Catherine S

    2016-09-15

    target the Gag protein, specifically by inhibiting CA-SP1 proteolytic cleavage. The lack of high-resolution structural information of the CA-SP1 target in Gag has hindered our understanding of the inhibitor-binding pocket and maturation inhibitor mode of action. Therefore, we utilized analogues of the maturation inhibitor PF-46396 as chemical tools to determine the chemical components of PF-46396 that contribute to antiviral activity and Gag binding and the relationship between these essential properties. This is the first study to report structure-activity relationships of the maturation inhibitor PF-46396. PF-46396 is chemically distinct from betulinic acid-derived maturation inhibitors; therefore, our data provide a foundation of knowledge that will aid our understanding of how structurally distinct maturation inhibitors act by similar modes of action. Copyright © 2016 Murgatroyd et al.

  14. Discovery and Characterization of Non-ATP Site Inhibitors of the Mitogen Activated Protein (MAP) Kinases

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Comess, Kenneth M.; Sun, Chaohong; Abad-Zapatero, Cele

    Inhibition of protein kinases has validated therapeutic utility for cancer, with at least seven kinase inhibitor drugs on the market. Protein kinase inhibition also has significant potential for a variety of other diseases, including diabetes, pain, cognition, and chronic inflammatory and immunologic diseases. However, as the vast majority of current approaches to kinase inhibition target the highly conserved ATP-binding site, the use of kinase inhibitors in treating nononcology diseases may require great selectivity for the target kinase. As protein kinases are signal transducers that are involved in binding to a variety of other proteins, targeting alternative, less conserved sites onmore » the protein may provide an avenue for greater selectivity. Here we report an affinity-based, high-throughput screening technique that allows nonbiased interrogation of small molecule libraries for binding to all exposed sites on a protein surface. This approach was used to screen both the c-Jun N-terminal protein kinase Jnk-1 (involved in insulin signaling) and p38{alpha} (involved in the formation of TNF{alpha} and other cytokines). In addition to canonical ATP-site ligands, compounds were identified that bind to novel allosteric sites. The nature, biological relevance, and mode of binding of these ligands were extensively characterized using two-dimensional {sup 1}H/{sup 13}C NMR spectroscopy, protein X-ray crystallography, surface plasmon resonance, and direct enzymatic activity and activation cascade assays. Jnk-1 and p38{alpha} both belong to the MAP kinase family, and the allosteric ligands for both targets bind similarly on a ledge of the protein surface exposed by the MAP insertion present in the CMGC family of protein kinases and distant from the active site. Medicinal chemistry studies resulted in an improved Jnk-1 ligand able to increase adiponectin secretion in human adipocytes and increase insulin-induced protein kinase PKB phosphorylation in human hepatocytes

  15. Genetic element from human surfactant protein SP-C gene confers bronchiolar-alveolar cell specificity in transgenic mice.

    PubMed

    Glasser, S W; Korfhagen, T R; Wert, S E; Bruno, M D; McWilliams, K M; Vorbroker, D K; Whitsett, J A

    1991-10-01

    Transgenic mice bearing chimeric genes consisting of 5'-sequences derived from the human surfactant protein C (SP-C) gene and the bacterial chloramphenicol acetyltransferase (CAT) gene were generated. Analysis of CAT activity was utilized to demonstrate tissue-specific and developmental expression of chimeric genes containing 3.7 kb of sequences from the human SP-C gene. Lung-specific expression of the 3.7 SP-C-CAT transgene was observed in eight distinct transgenic mouse lines. Expression of the 3.7 SP-C-CAT transgene was first detected in fetal lung on day 11 of gestation and increased dramatically with advancing gestational age, reaching adult levels of activity before birth. In situ hybridization demonstrated that expression of 3.7 SP-C-CAT mRNA was confined to the distal respiratory epithelium. Antisense CAT hybridization was detected in bronchiolar and type II epithelial cells in the adult lung of the 3.7 SP-C-CAT transgenic mice. In situ hybridization of four distinct 3.7 SP-C-CAT transgenic mouse lines demonstrated bronchiolar-alveolar expression of the chimeric CAT gene, although the relative intensity of expression at each site varied within the lines studied. Glucocorticoids increased murine SP-C mRNA in fetal lung organ culture. Likewise, expression of 3.7 SP-C-CAT transgene increased during fetal lung organ or explant culture and was further enhanced by glucocorticoid in vitro. The 5'-regions of human SP-C conferred developmental, lung epithelial, and glucocorticoid-enhanced expression of bacterial CAT in transgenic mice. The increased expression of SP-C accompanying prenatal lung development and exposure to glucocorticoid is mediated, at least in part, at the transcriptional level, being influenced by cis-active elements contained within the 5'-flanking region of the human SP-C gene.

  16. Effect of the NEP inhibitor SCH32615 on airway responses to intravenous substance P in guinea pigs.

    PubMed

    Shore, S A; Martins, M A; Drazen, J M

    1992-11-01

    We examined the effects of the selective neutral endopeptidase (NEP) inhibitor SCH32615 on airway responses to rapid intravenous infusions of substance P (SP) and neurokinin A (NKA) and on recovery of administered tachykinins from arterial blood in anesthetized mechanically ventilated guinea pigs. SCH32615, in doses that cause a marked increase in the magnitude of bronchoconstriction induced by infused NKA, had little effect on the changes in pulmonary conductance (GL) or dynamic compliance induced by SP. In animals in which SCH32615 (1 mg/kg) was administered in combination with the angiotensin-converting enzyme (ACE) inhibitor captopril (5.7 mg/kg), the dose of SP required to decrease GL by 50% was fourfold less than in animals that received captopril alone (P < 0.005). SP measured in arterial blood withdrawn within 45 s of intravenous administration of this tachykinin was not different in control and SCH32615-treated animals, whereas captopril caused an approximately threefold increase in SP concentrations (P < 0.005). When SCH32615 and captopril were administered together, significantly more SP was recovered than when captopril or SCH32615 was administered alone (P < 0.0005). Our results are consistent with the hypothesis that both NEP and ACE contribute to the degradation of intravenously infused SP. ACE degradation of SP is sufficient to limit SP-induced bronchoconstriction even in the presence of specific NEP inhibition.

  17. Genome-wide localization and expression profiling establish Sp2 as a sequence-specific transcription factor regulating vitally important genes

    PubMed Central

    Terrados, Gloria; Finkernagel, Florian; Stielow, Bastian; Sadic, Dennis; Neubert, Juliane; Herdt, Olga; Krause, Michael; Scharfe, Maren; Jarek, Michael; Suske, Guntram

    2012-01-01

    The transcription factor Sp2 is essential for early mouse development and for proliferation of mouse embryonic fibroblasts in culture. Yet its mechanisms of action and its target genes are largely unknown. In this study, we have combined RNA interference, in vitro DNA binding, chromatin immunoprecipitation sequencing and global gene-expression profiling to investigate the role of Sp2 for cellular functions, to define target sites and to identify genes regulated by Sp2. We show that Sp2 is important for cellular proliferation that it binds to GC-boxes and occupies proximal promoters of genes essential for vital cellular processes including gene expression, replication, metabolism and signalling. Moreover, we identified important key target genes and cellular pathways that are directly regulated by Sp2. Most significantly, Sp2 binds and activates numerous sequence-specific transcription factor and co-activator genes, and represses the whole battery of cholesterol synthesis genes. Our results establish Sp2 as a sequence-specific regulator of vitally important genes. PMID:22684502

  18. Autophagy-dependent generation of Axin2+ cancer stem-like cells promotes hepatocarcinogenesis in liver cirrhosis

    PubMed Central

    Li, J; Hu, S B; Wang, L Y; Zhang, X; Zhou, X; Yang, B; Li, J H; Xiong, J; Liu, N; Li, Y; Wu, Y Z; Zheng, Q C

    2017-01-01

    Autophagy is a pathophysiological phenomenon in liver cirrhosis that can further progress into hepatocarcinoma. Liver cancer stem cells (CSCs) are believed to initiate hepatocarcinogenesis. To investigate the precise mechanism related to the origin of CSCs in liver cirrhosis and hepatocarcinogenesis, we labeled Axin2+ hepatic cells with EGFP in Axin2Cre;Rosa26EGFP transgenic rats, and then stratified clinical and rat liver cirrhosis samples by autophagy flux. Clinical follow-up and lineage tracing in transgenic rat liver cirrhosis revealed that while Axin2/EGFP+ hepatic cells were present in normal livers and cirrhotic livers without aberrant autophagy, hepatic Axin2/EGFP+CD90+ cells were generated exclusively in cirrhotic livers with aberrant autophagy and promoted hepatocarcinogenesis. Aberrant autophagy in liver cirrhosis resulted in hepatocyte growth factor (HGF) expression, leading to activation of Met/JNK and Met/STAT3 signaling in sorted hepatic Axin2/EGFP+ cells and their transition into Axin2/EGFP+CD90+ cells that possess CSC properties. In a transgenic rat liver cirrhosis model, induction or inhibition of autophagy in cirrhotic livers by systemic administration of rapamycin or chloroquine or transfection with Atg3- and Atg7-shRNAs significantly induced or suppressed HGF expression, which in turn increased or reduced generation of EGFP+CD90+ hepatic cells by activating or inactivating Met/JNK and Met/STAT3 signaling, thereby promoting or preventing hepatocarcinogenesis. Systemic treatment with HGF-shRNA, SP600125 or stattic also reduced generation of EGFP(Axin2)+ hepatic cell-originated CD90+ CSCs in aberrant autophagic cirrhotic livers by inactivating HGF/Met/JNK or HGF/Met/STAT3 signaling, further preventing hepatocarcinogenesis. These data suggest that activation of Met/JNK and Met/STAT3 signaling in Axin2+ hepatic cells via autophagy-dependent HGF expression and the resultant generation of Axin2+CD90+ CSCs is a major mechanism of hepatocarcinogenesis

  19. Autophagy-dependent generation of Axin2+ cancer stem-like cells promotes hepatocarcinogenesis in liver cirrhosis.

    PubMed

    Li, J; Hu, S B; Wang, L Y; Zhang, X; Zhou, X; Yang, B; Li, J H; Xiong, J; Liu, N; Li, Y; Wu, Y Z; Zheng, Q C

    2017-11-30

    Autophagy is a pathophysiological phenomenon in liver cirrhosis that can further progress into hepatocarcinoma. Liver cancer stem cells (CSCs) are believed to initiate hepatocarcinogenesis. To investigate the precise mechanism related to the origin of CSCs in liver cirrhosis and hepatocarcinogenesis, we labeled Axin2+ hepatic cells with EGFP in Axin2Cre;Rosa26EGFP transgenic rats, and then stratified clinical and rat liver cirrhosis samples by autophagy flux. Clinical follow-up and lineage tracing in transgenic rat liver cirrhosis revealed that while Axin2/EGFP+ hepatic cells were present in normal livers and cirrhotic livers without aberrant autophagy, hepatic Axin2/EGFP+CD90+ cells were generated exclusively in cirrhotic livers with aberrant autophagy and promoted hepatocarcinogenesis. Aberrant autophagy in liver cirrhosis resulted in hepatocyte growth factor (HGF) expression, leading to activation of Met/JNK and Met/STAT3 signaling in sorted hepatic Axin2/EGFP+ cells and their transition into Axin2/EGFP+CD90+ cells that possess CSC properties. In a transgenic rat liver cirrhosis model, induction or inhibition of autophagy in cirrhotic livers by systemic administration of rapamycin or chloroquine or transfection with Atg3- and Atg7-shRNAs significantly induced or suppressed HGF expression, which in turn increased or reduced generation of EGFP+CD90+ hepatic cells by activating or inactivating Met/JNK and Met/STAT3 signaling, thereby promoting or preventing hepatocarcinogenesis. Systemic treatment with HGF-shRNA, SP600125 or stattic also reduced generation of EGFP(Axin2)+ hepatic cell-originated CD90+ CSCs in aberrant autophagic cirrhotic livers by inactivating HGF/Met/JNK or HGF/Met/STAT3 signaling, further preventing hepatocarcinogenesis. These data suggest that activation of Met/JNK and Met/STAT3 signaling in Axin2+ hepatic cells via autophagy-dependent HGF expression and the resultant generation of Axin2+CD90+ CSCs is a major mechanism of hepatocarcinogenesis

  20. Inhibition of spinal astrocytic c-Jun N-terminal kinase (JNK) activation correlates with the analgesic effects of ketamine in neuropathic pain

    PubMed Central

    2011-01-01

    Background We have previously reported that inhibition of astrocytic activation contributes to the analgesic effects of intrathecal ketamine on spinal nerve ligation (SNL)-induced neuropathic pain. However, the underlying mechanisms are still unclear. c-Jun N-terminal kinase (JNK), a member of mitogen-activated protein kinase (MAPK) family, has been reported to be critical for spinal astrocytic activation and neuropathic pain development after SNL. Ketamine can decrease lipopolysaccharide (LPS)-induced phosphorylated JNK (pJNK) expression and could thus exert its anti-inflammatory effect. We hypothesized that inhibition of astrocytic JNK activation might be involved in the suppressive effect of ketamine on SNL-induced spinal astrocytic activation. Methods Immunofluorescence histochemical staining was used to detect SNL-induced spinal pJNK expression and localization. The effects of ketamine on SNL-induced mechanical allodynia were confirmed by behavioral testing. Immunofluorescence histochemistry and Western blot were used to quantify the SNL-induced spinal pJNK expression after ketamine administration. Results The present study showed that SNL induced ipsilateral pJNK up-regulation in astrocytes but not microglia or neurons within the spinal dorsal horn. Intrathecal ketamine relieved SNL-induced mechanical allodynia without interfering with motor performance. Additionally, intrathecal administration of ketamine attenuated SNL-induced spinal astrocytic JNK activation in a dose-dependent manner, but not JNK protein expression. Conclusions The present results suggest that inhibition of JNK activation may be involved in the suppressive effects of ketamine on SNL-induced spinal astrocyte activation. Therefore, inhibition of spinal JNK activation may be involved in the analgesic effects of ketamine on SNL-induced neuropathic pain. PMID:21255465

  1. Improvement of liver injury and survival by JNK2 and iNOS deficiency in liver transplants from cardiac death mice.

    PubMed

    Liu, Qinlong; Rehman, Hasibur; Krishnasamy, Yasodha; Schnellmann, Rick G; Lemasters, John J; Zhong, Zhi

    2015-07-01

    Inclusion of liver grafts from cardiac death donors (CDD) would increase the availability of donor livers but is hampered by a higher risk of primary non-function. Here, we seek to determine mechanisms that contribute to primary non-function of liver grafts from CDD with the goal to develop strategies for improved function and outcome, focusing on c-Jun-N-terminal kinase (JNK) activation and mitochondrial depolarization, two known mediators of graft failure. Livers explanted from wild-type, inducible nitric oxide synthase knockout (iNOS(-/-)), JNK1(-/-) or JNK2(-/-) mice after 45-min aorta clamping were implanted into wild-type recipients. Mitochondrial depolarization was detected by intravital confocal microscopy in living recipients. After transplantation of wild-type CDD livers, graft iNOS expression and 3-nitrotyrosine adducts increased, but hepatic endothelial NOS expression was unchanged. Graft injury and dysfunction were substantially higher in CDD grafts than in non-CDD grafts. iNOS deficiency and inhibition attenuated injury and improved function and survival of CDD grafts. JNK1/2 and apoptosis signal-regulating kinase-1 activation increased markedly in wild-type CDD grafts, which was blunted by iNOS deficiency. JNK inhibition and JNK2 deficiency, but not JNK1 deficiency, decreased injury and improved function and survival of CDD grafts. Mitochondrial depolarization and binding of phospho-JNK2 to Sab, a mitochondrial protein linked to the mitochondrial permeability transition, were higher in CDD than in non-CDD grafts. iNOS deficiency, JNK inhibition and JNK2 deficiency all decreased mitochondrial depolarization and blunted ATP depletion in CDD grafts. JNK inhibition and deficiency did not decrease 3-nitrotyrosine adducts in CDD grafts. The iNOS-JNK2-Sab pathway promotes CDD graft failure via increased mitochondrial depolarization, and is an attractive target to improve liver function and survival in CDD liver transplantation recipients. Copyright © 2015

  2. Cone arrestin binding to JNK3 and Mdm2: conformational preference and localization of interaction sites

    PubMed Central

    Song, Xiufeng; Gurevich, Eugenia V.; Gurevich, Vsevolod V.

    2008-01-01

    Arrestins are multi-functional regulators of G protein-coupled receptors. Receptor-bound arrestins interact with >30 remarkably diverse proteins and redirect the signaling to G protein-independent pathways. The functions of free arrestins are poorly understood, and the interaction sites of the non-receptor arrestin partners are largely unknown. In this study, we show that cone arrestin, the least studied member of the family, binds c-Jun N-terminal kinase (JNK3) and Mdm2 and regulates their subcellular distribution. Using arrestin mutants with increased or reduced structural flexibility, we demonstrate that arrestin in all conformations binds JNK3 comparably, whereas Mdm2 preferentially binds cone arrestin ‘frozen’ in the basal state. To localize the interaction sites, we expressed separate N- and C-domains of cone and rod arrestins and found that individual domains bind JNK3 and remove it from the nucleus as efficiently as full-length proteins. Thus, the arrestin binding site for JNK3 includes elements in both domains with the affinity of partial sites on individual domains sufficient for JNK3 relocalization. N-domain of rod arrestin binds Mdm2, which localizes its main interaction site to this region. Comparable binding of JNK3 and Mdm2 to four arrestin subtypes allowed us to identify conserved residues likely involved in these interactions. PMID:17680991

  3. Detection of race-specific resistance against Puccinia coronata f. sp. avenae in Brachypodium species.

    PubMed

    Omidvar, Vahid; Dugyala, Sheshanka; Li, Feng; Rottschaefer, Susan; Miller, Marisa; Ayliffe, Michael; Moscou, Matthew James; Kianian, Shahryar F; Figueroa, Melania

    2018-06-20

    Oat crown rust caused by Puccinia coronata f. sp. avenae is the most destructive foliar disease of cultivated oat. Characterization of genetic factors controlling resistance responses to Puccinia coronata f. sp. avenae in non-host species could provide new resources for developing disease protection strategies in oat. We examined symptom development and fungal colonization levels of a collection of Brachypodium distachyon and B. hybridum accessions infected with three North American P. coronata f. sp. avenae isolates. Our results demonstrated that colonization phenotypes are dependent on both host and pathogen genotypes, indicating a role for race-specific responses in these interactions. These responses were independent of the accumulation of reactive oxygen species. Expression analysis of several defense-related genes suggested that salicylic acid and ethylene-mediated signaling, but not jasmonic acid are components of resistance reaction to P. coronata f. sp. avenae. Our findings provide the basis to conduct a genetic inheritance study to examine if effector-triggered immunity contributes to non-host resistance to P. coronata f. sp. avenae in Brachypodium species.

  4. PPARδ inhibits UVB-induced secretion of MMP-1 through MKP-7-mediated suppression of JNK signaling.

    PubMed

    Ham, Sun A; Kang, Eun S; Lee, Hanna; Hwang, Jung S; Yoo, Taesik; Paek, Kyung S; Park, Chankyu; Kim, Jin-Hoi; Lim, Dae-Seog; Seo, Han G

    2013-11-01

    In the present study, we investigated the role of peroxisome proliferator-activated receptor (PPAR) δ in modulating matrix-degrading metalloproteinases and other mechanisms underlying photoaging processes in the skin. In human dermal fibroblasts (HDFs), activation of PPARδ by its specific ligand GW501516 markedly attenuated UVB-induced secretion of matrix metalloproteinase (MMP)-1, concomitant with decreased generation of reactive oxygen species. These effects were significantly reduced in the presence of PPARδ small interfering RNA and GSK0660. Furthermore, c-Jun N-terminal kinase (JNK), but not p38 or extracellular signal-regulated kinase, mediated PPARδ-dependent inhibition of MMP-1 secretion in HDFs exposed to UVB. PPARδ-mediated messenger RNA stabilization of mitogen-activated protein kinase phosphatase (MKP)-7 was responsible for the GW501516-mediated inhibition of JNK signaling. Inhibition of UVB-induced secretion of MMP-1 by PPARδ was associated with the restoration of types I and III collagen to levels approaching those in cells not exposed to UVB. Finally, in HR-1 hairless mice exposed to UVB, administration of GW501516 significantly reduced wrinkle formation and skin thickness, downregulated MMP-1 and JNK phosphorylation, and restored the levels of MKP-7, types I and III collagen. These results suggest that PPARδ-mediated inhibition of MMP-1 secretion prevents some effects of photoaging and maintains the integrity of skin by inhibiting the degradation of the collagenous extracellular matrix.

  5. A dual-specificity isoform of the protein kinase inhibitor PKI produced by alternate gene splicing.

    PubMed

    Kumar, Priyadarsini; Walsh, Donal A

    2002-03-15

    We have previously shown that the protein kinase inhibitor beta (PKIbeta) form of the cAMP-dependent protein kinase inhibitor exists in multiple isoforms, some of which are specific inhibitors of the cAMP-dependent protein kinase, whereas others also inhibit the cGMP-dependent enzyme [Kumar, Van Patten and Walsh (1997), J. Biol. Chem. 272, 20011-20020]. We have now demonstrated that the switch from a cAMP-dependent protein kinase (PKA)-specific inhibitor to one with dual specificity arises as a consequence of alternate gene splicing. We have confirmed using bacterially produced pure protein that a single inhibitor species has dual specificity for both PKA and cGMP-dependent protein kinase (PKG), inhibiting each with very high and closely similar inhibitory potencies. The gene splicing converted a protein with 70 amino acids into one of 109 amino acids, and did not change the inhibitory potency to PKA, but changed it from a protein that had no detectable PKG inhibitory activity to one that now inhibited PKG in the nanomolar range.

  6. Histone-like DNA binding protein of Streptococcus intermedius induces the expression of pro-inflammatory cytokines in human monocytes via activation of ERK1/2 and JNK pathways.

    PubMed

    Liu, Dali; Yumoto, Hiromichi; Hirota, Katsuhiko; Murakami, Keiji; Takahashi, Kanako; Hirao, Kouji; Matsuo, Takashi; Ohkura, Kazuto; Nagamune, Hideaki; Miyake, Yoichiro

    2008-01-01

    Streptococcus intermedius is a commensal associated with serious, deep-seated purulent infections in major organs, such as the brain and liver. Histone-like DNA binding protein (HLP) is an accessory architectural protein in a variety of bacterial cellular processes. In this study, we investigated the mechanisms of pro-inflammatory cytokine inductions in THP-1 cells by stimulation with recombinant HLP of S. intermedius (rSi-HLP). rSi-HLP stimulation-induced production of pro-inflammatory cytokines (IL-8, IL-1 beta and TNF-alpha) occurred in a time- and dose-dependent manner. In contrast with the heat-stable activity of DNA binding, the induction activity of rSi-HLP was heat-unstable. In subsequent studies, rSi-HLP acted cooperatively with lipoteichoic acid, the synthetic Toll-like receptor 2 agonist, Pam3CSK4, and the cytosolic nucleotide binding oligomerization domain 2 receptor agonist, muramyldipeptide. Furthermore, Western blot and blocking assays with specific inhibitors showed that rSi-HLP stimulation induced the activation of cell signal transduction pathways, extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). In addition to its physiological role in bacterial growth through DNA binding, these results indicate that Si-HLP can trigger a cascade of events that induce pro-inflammatory responses via ERK1/2 and JNK signal pathways, and suggest that bacterial HLP may contribute to the activation of host innate immunity during bacterial infection.

  7. Nitric oxide balances osteoblast and adipocyte lineage differentiation via the JNK/MAPK signaling pathway in periodontal ligament stem cells.

    PubMed

    Yang, Shan; Guo, Lijia; Su, Yingying; Wen, Jing; Du, Juan; Li, Xiaoyan; Liu, Yitong; Feng, Jie; Xie, Yongmei; Bai, Yuxing; Wang, Hao; Liu, Yi

    2018-05-02

    Critical tissues that undergo regeneration in periodontal tissue are of mesenchymal origin; thus, investigating the regulatory mechanisms underlying the fate of periodontal ligament stem cells could be beneficial for application in periodontal tissue regeneration. Nitric oxide (NO) regulates many biological processes in developing embryos and adult stem cells. The present study was designed to investigate the effects of NO on the function of human periodontal ligament stem cells (PDLSCs) as well as to elucidate the underlying molecular mechanisms. Immunofluorescent staining and flow cytometry were used for stem cell identification. Western blot, reverse transcription polymerase chain reaction (RT-PCR), immunofluorescent staining, and flow cytometry were used to examine the expression of NO-synthesizing enzymes. The proliferative capacity of PDLSCs was determined by EdU assays. The osteogenic potential of PDLSCs was tested using alkaline phosphatase (ALP) staining, Alizarin Red staining, and calcium concentration detection. Oil Red O staining was used to analyze the adipogenic ability. Western blot, RT-PCR, and staining were used to examine the signaling pathway. Human PDLSCs expressed both inducible NO synthase (iNOS) and endothelial NO synthase (eNOS) and produced NO. Blocking the generation of NO with the NOS inhibitor L-N G -monomethyl arginine (L-NMMA) had no influence on PDLSC proliferation and apoptosis but significantly attenuated the osteogenic differentiation capacity and stimulated the adipogenic differentiation capacity of PDLSCs. Increasing the physiological level of NO with NO donor sodium nitroprusside (SNP) significantly promoted the osteogenic differentiation capacity but reduced the adipogenic differentiation capacity of PDLSCs. NO balances the osteoblast and adipocyte lineage differentiation in periodontal ligament stem cells via the c-Jun N-terminal kinase (JNK)/mitogen-activated protein kinase (MAPK) signaling pathway. NO is essential for

  8. Protective effect of Ginkgo biloba leaves extract, EGb761, on endotoxin-induced acute lung injury via a JNK- and Akt-dependent NFκB pathway.

    PubMed

    Lee, Chien-Ying; Yang, Jiann-Jou; Lee, Shiuan-Shinn; Chen, Chun-Jung; Huang, Yi-Chun; Huang, Kuang-Hua; Kuan, Yu-Hsiang

    2014-07-09

    Acute lung injury (ALI) is a clinical syndrome mainly caused by Gram-negative bacteria which is still in need of an effective therapeutic medicine. EGb761, an extract of Ginkgo biloba leaves, has several bioeffects including anti-inflammation, cardioprotection, neuroprotection, and free radical scavenging. Preadministration of EGb761 inhibited lipopolysaccharide (LPS)-induced histopathological changes and exchange of arterial blood gas. In addition, LPS-induced expression of proinflammatory mediators, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, macrophage inflammatory protein (MIP)-2, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), were suppressed by EGb761. The activation of nuclear factor (NF)κB, a transcription factor of proinflammatory mediators, and phosphorylation of IκB, an inhibitor of NFκB, were also reduced by EGb761. Furthermore, we found the inhibitory concentration of EGb761 on phosphorylation of JNK and Akt was less than those of ERK and p38 MAPK. In conclusion, EGb761 is a potential protective agent for ALI, possibly via downregulating the JNK- and Akt-dependent NFκB activation pathway.

  9. Purification of charybdotoxine, a specific inhibitor of the high-conductance Ca/sup 2 +/-activated K/sup +/ channel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smith, C.; Phillips, M.; Miller, C.

    1986-11-05

    Charybdotoxim is a high-affinity specific inhibitor of the high-conductance Ca/sup 2 +/-activated K/sup +/ channel found in the plasma membranes of many vertebrate cell types. Using Ca/sup 2 +/-activated K/sup +/ channels reconstituted into planar lipid bilayer membranes as an assay, the authors have purified the toxin from the venom of the scorpion Leiurus quinquestriatus by a two-step procedure involving chromatofocusing on SP-Sephadex, followed by reversed-phase high-performance liquid chromatography. Charybdotoxin is shown to be a highly basic protein with a mass of 10 kDa. Under the standard assay conditions, the purified toxin inhibits the Ca/sup 2 +/-activated K/sup +/ channelmore » with an apparent dissociation constant of 3.5 nM. The protein is unusually stable, with inhibitory potency being insensitive to boiling or exposure to organic solvents. The toxin's activity is sensitive to chymotrypsin treatment and to acylation of lysine groups. The protein may be radioiodinated without loss of activity.« less

  10. Computationally designed high specificity inhibitors delineate the roles of BCL2 family proteins in cancer.

    PubMed

    Berger, Stephanie; Procko, Erik; Margineantu, Daciana; Lee, Erinna F; Shen, Betty W; Zelter, Alex; Silva, Daniel-Adriano; Chawla, Kusum; Herold, Marco J; Garnier, Jean-Marc; Johnson, Richard; MacCoss, Michael J; Lessene, Guillaume; Davis, Trisha N; Stayton, Patrick S; Stoddard, Barry L; Fairlie, W Douglas; Hockenbery, David M; Baker, David

    2016-11-02

    Many cancers overexpress one or more of the six human pro-survival BCL2 family proteins to evade apoptosis. To determine which BCL2 protein or proteins block apoptosis in different cancers, we computationally designed three-helix bundle protein inhibitors specific for each BCL2 pro-survival protein. Following in vitro optimization, each inhibitor binds its target with high picomolar to low nanomolar affinity and at least 300-fold specificity. Expression of the designed inhibitors in human cancer cell lines revealed unique dependencies on BCL2 proteins for survival which could not be inferred from other BCL2 profiling methods. Our results show that designed inhibitors can be generated for each member of a closely-knit protein family to probe the importance of specific protein-protein interactions in complex biological processes.

  11. Opposing roles of p38 and JNK in a Drosophila model of TDP-43 proteinopathy reveal oxidative stress and innate immunity as pathogenic components of neurodegeneration.

    PubMed

    Zhan, Lihong; Xie, Qijing; Tibbetts, Randal S

    2015-02-01

    Pathological aggregation and mutation of the 43-kDa TAR DNA-binding protein (TDP-43) are strongly implicated in the pathogenesis amyotrophic lateral sclerosis and frontotemporal lobar degeneration. TDP-43 neurotoxicity has been extensively modeled in mice, zebrafish, Caenorhabditis elegans and Drosophila, where selective expression of TDP-43 in motoneurons led to paralysis and premature lethality. Through a genetic screen aimed to identify genetic modifiers of TDP-43, we found that the Drosophila dual leucine kinase Wallenda (Wnd) and its downstream kinases JNK and p38 influenced TDP-43 neurotoxicity. Reducing Wnd gene dosage or overexpressing its antagonist highwire partially rescued TDP-43-associated premature lethality. Downstream of Wnd, the JNK and p38 kinases played opposing roles in TDP-43-associated neurodegeneration. LOF alleles of the p38b gene as well as p38 inhibitors diminished TDP-43-associated premature lethality, whereas p38b GOF caused phenotypic worsening. In stark contrast, disruptive alleles of Basket (Bsk), the Drosophila homologue of JNK, exacerbated longevity shortening, whereas overexpression of Bsk extended lifespan. Among possible mechanisms, we found motoneuron-directed expression of TDP-43 elicited oxidative stress and innate immune gene activation that were exacerbated by p38 GOF and Bsk LOF, respectively. A key pathologic role for innate immunity in TDP-43-associated neurodegeneration was further supported by the finding that genetic suppression of the Toll/Dif and Imd/Relish inflammatory pathways dramatically extended lifespan of TDP-43 transgenic flies. We propose that oxidative stress and neuroinflammation are intrinsic components of TDP-43-associated neurodegeneration and that the balance between cytoprotective JNK and cytotoxic p38 signaling dictates phenotypic outcome to TDP-43 expression in Drosophila. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Anticancer Activity of Marine Sponge Hyrtios sp. Extract in Human Colorectal Carcinoma RKO Cells with Different p53 Status

    PubMed Central

    Lim, Hyun Kyung; Bae, Woori; Lee, Hyi-Seung

    2014-01-01

    Drug development using marine bioresources is limited even though the ocean occupies about 70% of the earth and contains a large number of biological materials. From the screening test of the marine sponge extracts, we found Hyrtios sp. sponge collected from Chuuk island, Micronesia. In this study, the Hyrtios sp. extract was examined for anticancer activity against human colorectal carcinoma RKO cells that are wildtype for p53 and RKO-E6 that are p53 defective. The Hyrtios sp. extract dose-dependently inhibited viability in both cell lines. Multinucleation as an indication of mitotic catastrophe was also observed. Cytotoxicity tests gave significantly different results for RKO and RKO-E6 cells after 48 h exposure to Hyrtios sp. extract. In RKO cells treated with Hyrtios sp. extract, cell death occurred by induction of p53 and p21 proteins. In p53-defective RKO-E6 cells, Hyrtios sp. extract decreased expression of JNK protein and increased p21 protein. These results indicate that Hyrtios sp. extract induced apoptosis via different pathways depending on p53 status and could be a good natural product for developing new anticancer drugs. PMID:25243139

  13. Simplified assays of lipolysis enzymes for drug discovery and specificity assessment of known inhibitors.

    PubMed

    Iglesias, Jose; Lamontagne, Julien; Erb, Heidi; Gezzar, Sari; Zhao, Shangang; Joly, Erik; Truong, Vouy Linh; Skorey, Kathryn; Crane, Sheldon; Madiraju, S R Murthy; Prentki, Marc

    2016-01-01

    Lipids are used as cellular building blocks and condensed energy stores and also act as signaling molecules. The glycerolipid/ fatty acid cycle, encompassing lipolysis and lipogenesis, generates many lipid signals. Reliable procedures are not available for measuring activities of several lipolytic enzymes for the purposes of drug screening, and this resulted in questionable selectivity of various known lipase inhibitors. We now describe simple assays for lipolytic enzymes, including adipose triglyceride lipase (ATGL), hormone sensitive lipase (HSL), sn-1-diacylglycerol lipase (DAGL), monoacylglycerol lipase, α/β-hydrolase domain 6, and carboxylesterase 1 (CES1) using recombinant human and mouse enzymes either in cell extracts or using purified enzymes. We observed that many of the reported inhibitors lack specificity. Thus, Cay10499 (HSL inhibitor) and RHC20867 (DAGL inhibitor) also inhibit other lipases. Marked differences in the inhibitor sensitivities of human ATGL and HSL compared with the corresponding mouse enzymes was noticed. Thus, ATGListatin inhibited mouse ATGL but not human ATGL, and the HSL inhibitors WWL11 and Compound 13f were effective against mouse enzyme but much less potent against human enzyme. Many of these lipase inhibitors also inhibited human CES1. Results describe reliable assays for measuring lipase activities that are amenable for drug screening and also caution about the specificity of the many earlier described lipase inhibitors. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

  14. Simplified assays of lipolysis enzymes for drug discovery and specificity assessment of known inhibitors

    PubMed Central

    Iglesias, Jose; Lamontagne, Julien; Erb, Heidi; Gezzar, Sari; Zhao, Shangang; Joly, Erik; Truong, Vouy Linh; Skorey, Kathryn; Crane, Sheldon; Madiraju, S. R. Murthy; Prentki, Marc

    2016-01-01

    Lipids are used as cellular building blocks and condensed energy stores and also act as signaling molecules. The glycerolipid/ fatty acid cycle, encompassing lipolysis and lipogenesis, generates many lipid signals. Reliable procedures are not available for measuring activities of several lipolytic enzymes for the purposes of drug screening, and this resulted in questionable selectivity of various known lipase inhibitors. We now describe simple assays for lipolytic enzymes, including adipose triglyceride lipase (ATGL), hormone sensitive lipase (HSL), sn-1-diacylglycerol lipase (DAGL), monoacylglycerol lipase, α/β-hydrolase domain 6, and carboxylesterase 1 (CES1) using recombinant human and mouse enzymes either in cell extracts or using purified enzymes. We observed that many of the reported inhibitors lack specificity. Thus, Cay10499 (HSL inhibitor) and RHC20867 (DAGL inhibitor) also inhibit other lipases. Marked differences in the inhibitor sensitivities of human ATGL and HSL compared with the corresponding mouse enzymes was noticed. Thus, ATGListatin inhibited mouse ATGL but not human ATGL, and the HSL inhibitors WWL11 and Compound 13f were effective against mouse enzyme but much less potent against human enzyme. Many of these lipase inhibitors also inhibited human CES1. Results describe reliable assays for measuring lipase activities that are amenable for drug screening and also caution about the specificity of the many earlier described lipase inhibitors. PMID:26423520

  15. PEGylated DX-1000: pharmacokinetics and antineoplastic activity of a specific plasmin inhibitor.

    PubMed

    Devy, Laetitia; Rabbani, Shafaat A; Stochl, Mark; Ruskowski, Mary; Mackie, Ian; Naa, Laurent; Toews, Mark; van Gool, Reinoud; Chen, Jie; Ley, Art; Ladner, Robert C; Dransfield, Daniel T; Henderikx, Paula

    2007-11-01

    Novel inhibitors of the urokinase-mediated plasminogen (plg) activation system are potentially of great clinical benefit as anticancer treatments. Using phage display, we identified DX-1000 a tissue factor pathway inhibitor-derived Kunitz domain protein which is a specific high-affinity inhibitor of plasmin (pln) (K(i) = 99 pM). When tested in vitro, DX-1000 blocks plasmin-mediated pro-matrix metalloproteinase-9 (proMMP-9) activation on cells and dose-dependently inhibits tube formation, while not significantly affecting hemostasis and coagulation. However, this low-molecular weight protein inhibitor ( approximately 7 kDa) exhibits rapid plasma clearance in mice and rabbits, limiting its potential clinical use in chronic diseases. After site-specific PEGylation, DX-1000 retains its activity and exhibits a decreased plasma clearance. This PEGylated derivative is effective in vitro, as well as potent in inhibiting tumor growth of green fluorescent protein (GFP)-labeled MDA-MB-231 cells. 4PEG-DX-1000 treatment causes a significant reduction of urokinase-type plasminogen activator (uPA) and plasminogen expressions, a reduction of tumor proliferation, and vascularization. 4PEG-DX-1000 treatment significantly decreases the level of active mitogen-activated protein kinase (MAPK) in the primary tumors and reduces metastasis incidence. Together, our results demonstrate the potential value of plasmin inhibitors as therapeutic agents for blocking breast cancer growth and metastasis.

  16. Potent activity of the HIV-1 maturation inhibitor bevirimat in SCID-hu Thy/Liv mice.

    PubMed

    Stoddart, Cheryl A; Joshi, Pheroze; Sloan, Barbara; Bare, Jennifer C; Smith, Philip C; Allaway, Graham P; Wild, Carl T; Martin, David E

    2007-11-28

    The HIV-1 maturation inhibitor, 3-O-(3',3'-dimethylsuccinyl) betulinic acid (bevirimat, PA-457) is a promising drug candidate with 10 nM in vitro antiviral activity against multiple wild-type (WT) and drug-resistant HIV-1 isolates. Bevirimat has a novel mechanism of action, specifically inhibiting cleavage of spacer peptide 1 (SP1) from the C-terminus of capsid which results in defective core condensation. Oral administration of bevirimat to HIV-1-infected SCID-hu Thy/Liv mice reduced viral RNA by >2 log(10) and protected immature and mature T cells from virus-mediated depletion. This activity was observed at plasma concentrations that are achievable in humans after oral dosing, and bevirimat was active up to 3 days after inoculation with both WT HIV-1 and an AZT-resistant HIV-1 clinical isolate. Consistent with its mechanism of action, bevirimat caused a dose-dependent inhibition of capsid-SP1 cleavage in HIV-1-infected human thymocytes obtained from these mice. HIV-1 NL4-3 with an alanine-to-valine substitution at the N-terminus of SP1 (SP1/A1V), which is resistant to bevirimat in vitro, was also resistant to bevirimat treatment in the mice, and SP1/AIV had replication and thymocyte kinetics similar to that of WT NL4-3 with no evidence of fitness impairment in in vivo competition assays. Interestingly, protease inhibitor-resistant HIV-1 with impaired capsid-SP1 cleavage was hypersensitive to bevirimat in vitro with a 50% inhibitory concentration 140 times lower than for WT HIV-1. These results support further clinical development of this first-in-class maturation inhibitor and confirm the usefulness of the SCID-hu Thy/Liv model for evaluation of in vivo antiretroviral efficacy, drug resistance, and viral fitness.

  17. Coexisting bacterial populations responsible for multiphasic mineralization kinetics in soil. [Janthinobacterium sp. Rhodococcus sp

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schmidt, S.K.; Gier, M.J.

    1990-09-01

    Experiments were conducted to study populations of indigenous microorganisms capable of mineralizing 2,4-dinitrophenol (DNP) in two soils. Previous kinetic analyses indicated the presence of two coexisting populations of DNP-mineralizing microorganisms in a forest soil (soil 1). Studies in which eucaryotic and procaryotic inhibitors were added to this soil indicated that both populations were bacterial. Most-probable-number counts with media containing different concentrations of DNP indicated that more bacteria could mineralize low concentrations of DNP than could metabolize high concentrations of it. Enrichments with varying concentrations of DNP and various combinations of inhibitors consistently resulted in the isolation of the same twomore » species of bacteria from soil 1. This soil contained a large number and variety of fungi, but no fungi capable of mineralizing DNP were isolated. The two bacterial isolates were identified as a Janthinobacterium sp. and a Rhodococcus sp. The Janthinobacterium sp. had a low {mu}{sub max} and a low K{sub m} for DNP mineralization, whereas the Rhodococcus sp. had much higher values for both parameters. These differences between the two species of bacteria were similar to differences seen when soil was incubated with different concentrations of DNP. Values for {mu}{sub max} from soil incubations were similar to {mu}{sub max} values obtained in pure culture studies. In contrast, K{sub s} and K{sub m} values showed greater variation between soil and pure culture studies.« less

  18. Computationally designed high specificity inhibitors delineate the roles of BCL2 family proteins in cancer

    PubMed Central

    Berger, Stephanie; Procko, Erik; Margineantu, Daciana; Lee, Erinna F; Shen, Betty W; Zelter, Alex; Silva, Daniel-Adriano; Chawla, Kusum; Herold, Marco J; Garnier, Jean-Marc; Johnson, Richard; MacCoss, Michael J; Lessene, Guillaume; Davis, Trisha N; Stayton, Patrick S; Stoddard, Barry L; Fairlie, W Douglas; Hockenbery, David M; Baker, David

    2016-01-01

    Many cancers overexpress one or more of the six human pro-survival BCL2 family proteins to evade apoptosis. To determine which BCL2 protein or proteins block apoptosis in different cancers, we computationally designed three-helix bundle protein inhibitors specific for each BCL2 pro-survival protein. Following in vitro optimization, each inhibitor binds its target with high picomolar to low nanomolar affinity and at least 300-fold specificity. Expression of the designed inhibitors in human cancer cell lines revealed unique dependencies on BCL2 proteins for survival which could not be inferred from other BCL2 profiling methods. Our results show that designed inhibitors can be generated for each member of a closely-knit protein family to probe the importance of specific protein-protein interactions in complex biological processes. DOI: http://dx.doi.org/10.7554/eLife.20352.001 PMID:27805565

  19. Ectopic expression of H2AX protein promotes TrkA-induced cell death via modulation of TrkA tyrosine-490 phosphorylation and JNK activity upon DNA damage

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jung, Eun Joo; Kim, Deok Ryong, E-mail: drkim@gnu.ac.kr

    2011-01-21

    Research highlights: {yields} We established TrkA-inducible U2OS cells stably expressing GFP-H2AX proteins. {yields} GFP-H2AX was colocalized with TrkA in the cytoplasm. {yields} {gamma}H2AX production was significantly increased upon activation of TrkA and suppressed by TrkA inhibitor or JNK inhibitor. {yields} Ectopic expression of H2AX promoted TrkA-mediated cell death through the modulation of TrkA tyrosine-490 phosphorylation and JNK activity upon DNA damage. -- Abstract: We previously reported that TrkA overexpression causes accumulation of {gamma}H2AX proteins in the cytoplasm, subsequently leading to massive cell death in U2OS cells. To further investigate how cytoplasmic H2AX is associated with TrkA-induced cell death, we establishedmore » TrkA-inducible cells stably expressing GFP-tagged H2AX. We found that TrkA co-localizes with ectopically expressed GFP-H2AX proteins in the cytoplasm, especially at the juxta-nuclear membranes, which supports our previous results about a functional connection between TrkA and {gamma}H2AX in TrkA-induced cell death. {gamma}H2AX production from GFP-H2AX proteins was significantly increased when TrkA was overexpressed. Moreover, ectopic expression of H2AX activated TrkA-mediated signal pathways via up-regulation of TrkA tyrosine-490 phosphorylation. In addition, suppression of TrkA tyrosine-490 phosphorylation under a certain condition was removed by ectopic expression of H2AX, indicating a functional role of H2AX in the maintenance of TrkA activity. Indeed, TrkA-induced cell death was highly elevated by ectopic H2AX expression, and it was further accelerated by DNA damage via JNK activation. These all results suggest that cytoplasmic H2AX could play an important role in TrkA-mediated cell death by modulating TrkA upon DNA damage.« less

  20. MarvelD3 couples tight junctions to the MEKK1–JNK pathway to regulate cell behavior and survival

    PubMed Central

    Steed, Emily; Elbediwy, Ahmed; Vacca, Barbara; Dupasquier, Sébastien; Hemkemeyer, Sandra A.; Suddason, Tesha; Costa, Ana C.; Beaudry, Jean-Bernard; Zihni, Ceniz; Gallagher, Ewen; Pierreux, Christophe E.

    2014-01-01

    MarvelD3 is a transmembrane component of tight junctions, but there is little evidence for a direct involvement in the junctional permeability barrier. Tight junctions also regulate signaling mechanisms that guide cell proliferation; however, the transmembrane components that link the junction to such signaling pathways are not well understood. In this paper, we show that MarvelD3 is a dynamic junctional regulator of the MEKK1–c-Jun NH2-terminal kinase (JNK) pathway. Loss of MarvelD3 expression in differentiating Caco-2 cells resulted in increased cell migration and proliferation, whereas reexpression in a metastatic tumor cell line inhibited migration, proliferation, and in vivo tumor formation. Expression levels of MarvelD3 inversely correlated with JNK activity, as MarvelD3 recruited MEKK1 to junctions, leading to down-regulation of JNK phosphorylation and inhibition of JNK-regulated transcriptional mechanisms. Interplay between MarvelD3 internalization and JNK activation tuned activation of MEKK1 during osmotic stress, leading to junction dissociation and cell death in MarvelD3-depleted cells. MarvelD3 thus couples tight junctions to the MEKK1–JNK pathway to regulate cell behavior and survival. PMID:24567356

  1. Utilization of Fishery Processing By-Product Squid Pens for α-Glucosidase Inhibitors Production by Paenibacillus sp.

    PubMed

    Nguyen, Van Bon; Nguyen, Anh Dzung; Wang, San-Lang

    2017-08-30

    The supernatants (the solution part received after centrifugation) of squid pens fermented by four species of Paenibacillus showed potent inhibitory activity against α-glucosidases derived from yeast (79-98%) and rats (76-83%). The inhibition of acarbose-a commercial antidiabetic drug, used against yeast and rat α-glucosidases-was tested for comparison; it showed inhibitory activity of 64% and 88%, respectively. Other chitinolytic or proteolytic enzyme-producing bacterial strains were also used to ferment squid pens, but no inhibition activity was detected from the supernatants. Paenibacillus sp. TKU042, the most active α-glucosidase inhibitor (aGI)-producing strain, was selected to determine the optimal cultivation parameters. This bacterium achieved the highest aGI productivity (527 µg/mL) when 1% squid pens were used as the sole carbon/nitrogen source with a medium volume of 130 mL (initial pH 6.85) in a 250 mL flask (48% of air head space), at 30 °C for 3-4 d. The aGI productivity increased 3.1-fold after optimization of the culture conditions. Some valuable characteristics of Paenibacillus aGIs were also studied, including pH and thermal stability and specific inhibitory activity. These microbial aGIs showed efficient inhibition against α-glucosidases from rat, yeast, and bacteria, but weak inhibition against rice α-glucosidase with IC 50 values of 362, 252, 189, and 773 µg/mL, respectively. In particular, these aGIs showed highly stable activity over a large pH (2-13) and temperature range (40-100 °C). Various techniques, including: Diaoin, Octadecylsilane opened columns, and preparative HPLC coupled with testing bioactivity resulted in isolating a main active compound; this major inhibitor was identified as homogentisic acid (HGA). Notably, HGA was confirmed as a new inhibitor, a non-sugar-based aGI, and as possessing stronger activity than acarbose with IC 50, and maximum inhibition values of 220 μg/mL, 95%, and 1510 μg/mL, 65%, respectively

  2. Neuroprotective effects of curcumin on endothelin-1 mediated cell death in hippocampal neurons.

    PubMed

    Stankowska, Dorota L; Krishnamoorthy, Vignesh R; Ellis, Dorette Z; Krishnamoorthy, Raghu R

    2017-06-01

    Alzheimer's disease is a progressive neurodegenerative disease characterized by loss of hippocampal neurons leading to memory deficits and cognitive decline. Studies suggest that levels of the vasoactive peptide endothelin-1 (ET-1) are increased in the brain tissue of Alzheimer's patients. Curcumin, the main ingredient of the spice turmeric, has been shown to have anti-inflammatory, anti-cancer, and neuroprotective effects. However, the mechanisms underlying some of these beneficial effects are not completely understood. The objective of this study was to determine if curcumin could protect hippocampal neurons from ET-1 mediated cell death and examine the involvement of c-Jun in this pathway. Primary hippocampal neurons from rat pups were isolated using a previously published protocol. Viability of the cells was measured by the live/dead assay. Immunoblot and immunohistochemical analyses were performed to analyze c-Jun levels in hippocampal neurons treated with either ET-1 or a combination of ET-1 and curcumin. Apoptotic changes were evaluated by immunoblot detection of cleaved caspase-3, cleaved fodrin, and a caspase 3/7 activation assay. ET-1 treatment produced a 2-fold increase in the levels of c-Jun as determined by an immunoblot analysis in hippocampal neurons. Co-treatment with curcumin significantly attenuated the ET-1 mediated increase in c-Jun levels. ET-1 caused increased neuronal cell death of hippocampal neurons indicated by elevation of cleaved caspase-3, cleaved fodrin and an increased activity of caspases 3 and 7 which was attenuated by co-treatment with curcumin. Blockade of JNK, an upstream effector of c-Jun by specific inhibitor SP600125 did not fully protect from ET-1 mediated activation of pro-apoptotic enzymes in primary hippocampal cells. Our data suggests that one mechanism by which curcumin protects against ET-1-mediated cell death is through blocking an increase in c-Jun levels. Other possible mechanisms include decreasing pro

  3. The effect of menadione on glutathione S-transferase A1 (GSTA1): c-Jun N-terminal kinase (JNK) complex dissociation in human colonic adenocarcinoma Caco-2 cells.

    PubMed

    Adnan, Humaira; Antenos, Monica; Kirby, Gordon M

    2012-10-02

    Glutathione S-transferases (GSTs) act as modulators of mitogen-activated protein kinase signal transduction pathways via a mechanism involving protein-protein interactions. We have demonstrated that GSTA1 forms complexes with JNK and modifies JNK activation during cellular stress, but the factors that influence complex association and dissociation are unknown. We hypothesized that menadione causes dissociation of GSTA1-JNK complexes, activates JNK, and the consequences of menadione exposure depend on GSTA1 expression. We demonstrate that menadione causes GSTA1-JNK dissociation and JNK activation in preconfluent Caco-2 cells, whereas postconfluent cells are resistant to this effect. Moreover, preconfluent cells are more sensitive than postconfluent cells to menadione-induced cytotoxicity. Activation of JNK is transient since removal of menadione causes GSTA1 to re-associate with JNK reducing cytotoxicity. Over-expression and knockdown of GSTA1 did not alter JNK activation by menadione or sensitivity to menadione-induced cytotoxicity. These results indicate that GSTA1-JNK complex integrity does not affect the ability of menadione to activate JNK. N-acetyl cysteine prevents GSH depletion and blocks menadione-induced complex dissociation, JNK activation and inhibits menadione-induced cytotoxicity. JNK activation and inhibits menadione-induced cytotoxicity. The data suggest that the mechanism of menadione-induced JNK activation involves the production of reactive oxygen species, likely superoxide anion, and intracellular GSH levels play an important role in preventing GSTA1-JNK complex dissociation, subsequent JNK activation and induction of cytotoxicity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. [Curcumin alleviates early brain injury following subarachnoid hemorrhage in rats by inhibiting JNK/c-Jun signal pathway].

    PubMed

    Li, Xia; Zhu, Ji

    2018-03-01

    Objective To investigate the inhibitory effect of curcumin on early brain injury following subarachnoid hemorrhage (SAH) by inhibiting JNK/ c-Jun signal pathway. Methods Sixty adult male SD rats were randomly divided into four groups: sham operation group (sham group), SAH group, SAH group treated with 100 mg/(kg.d) curcumin and SAH group treated with 200 mg/(kg.d) curcumin, with 15 rats in each group. Endovascular puncture was used to induce SAH model. Nissl staining was used to test whether neurons were broken. TUNEL staining was used to detect apoptosis. Immunohistochemistry was used to investigate the expression of caspase-3. Western blot analysis was used to detect the expressions of p-JNK, JNK, p-c-Jun, c-Jun, and caspase-3. Results Nissl staining indicated the decrease of Nissl bodies in SAH group, but increase of Nissl bodies in SAH group treated with curcumin. TUNEL staining showed that there were more apoptotic neurons in SAH group compared with sham group, while apoptotic neurons decreased after the treatment with curcumin, more obviously in the group treated with 200 mg/(kg.d) curcumin. The expressions of p-JNK, JNK, p-c-Jun, c-Jun, and caspase-3 were up-regulated in SAH group compared with sham group. However, the expressions of those proteins were down-regulated after the treatment with curcumin, especially by higher-dose curcumin treatment. Conclusion Curcumin might suppress early brain injury after SAH by inhibiting JNK/c-Jun signal pathway and neuron apoptosis.

  5. A Novel c-Jun N-terminal Kinase (JNK) Signaling Complex Involved in Neuronal Migration during Brain Development.

    PubMed

    Zhang, Feng; Yu, Jingwen; Yang, Tao; Xu, Dan; Chi, Zhixia; Xia, Yanheng; Xu, Zhiheng

    2016-05-27

    Disturbance of neuronal migration may cause various neurological disorders. Both the transforming growth factor-β (TGF-β) signaling and microcephaly-associated protein WDR62 are important for neuronal migration during brain development; however, the underlying molecular mechanisms involved remain unclear. We show here that knock-out or knockdown of Tak1 (TGFβ-activated kinase 1) and Jnk2 (c-Jun N-terminal kinase 2) perturbs neuronal migration during cortical development and that the migration defects incurred by knock-out and/or knockdown of Tβr2 (type II TGF-β receptor) or Tak1 can be partially rescued by expression of TAK1 and JNK2, respectively. Furthermore, TAK1 forms a protein complex with RAC1 and two scaffold proteins of the JNK pathway, the microcephaly-associated protein WDR62 and the RAC1-interacting protein POSH (plenty of Src homology). Components of the complex coordinate with each other in the regulation of TAK1 as well as JNK activities. We suggest that unique JNK protein complexes are involved in the diversified biological and pathological functions during brain development and pathogenesis of diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Identification of STAT1 and STAT3 Specific Inhibitors Using Comparative Virtual Screening and Docking Validation

    PubMed Central

    Szelag, Malgorzata; Czerwoniec, Anna; Wesoly, Joanna; Bluyssen, Hans A. R.

    2015-01-01

    Signal transducers and activators of transcription (STATs) facilitate action of cytokines, growth factors and pathogens. STAT activation is mediated by a highly conserved SH2 domain, which interacts with phosphotyrosine motifs for specific STAT-receptor contacts and STAT dimerization. The active dimers induce gene transcription in the nucleus by binding to a specific DNA-response element in the promoter of target genes. Abnormal activation of STAT signaling pathways is implicated in many human diseases, like cancer, inflammation and auto-immunity. Searches for STAT-targeting compounds, exploring the phosphotyrosine (pTyr)-SH2 interaction site, yielded many small molecules for STAT3 but sparsely for other STATs. However, many of these inhibitors seem not STAT3-specific, thereby questioning the present modeling and selection strategies of SH2 domain-based STAT inhibitors. We generated new 3D structure models for all human (h)STATs and developed a comparative in silico docking strategy to obtain further insight into STAT-SH2 cross-binding specificity of a selection of previously identified STAT3 inhibitors. Indeed, by primarily targeting the highly conserved pTyr-SH2 binding pocket the majority of these compounds exhibited similar binding affinity and tendency scores for all STATs. By comparative screening of a natural product library we provided initial proof for the possibility to identify STAT1 as well as STAT3-specific inhibitors, introducing the ‘STAT-comparative binding affinity value’ and ‘ligand binding pose variation’ as selection criteria. In silico screening of a multi-million clean leads (CL) compound library for binding of all STATs, likewise identified potential specific inhibitors for STAT1 and STAT3 after docking validation. Based on comparative virtual screening and docking validation, we developed a novel STAT inhibitor screening tool that allows identification of specific STAT1 and STAT3 inhibitory compounds. This could increase our

  7. SP6616 as a new Kv2.1 channel inhibitor efficiently promotes β-cell survival involving both PKC/Erk1/2 and CaM/PI3K/Akt signaling pathways.

    PubMed

    Zhou, T T; Quan, L L; Chen, L P; Du, T; Sun, K X; Zhang, J C; Yu, L; Li, Y; Wan, P; Chen, L L; Jiang, B H; Hu, L H; Chen, J; Shen, X

    2016-05-05

    Kv2.1 as a voltage-gated potassium (Kv) channel subunit has a pivotal role in the regulation of glucose-stimulated insulin secretion (GSIS) and pancreatic β-cell apoptosis, and is believed to be a promising target for anti-diabetic drug discovery, although the mechanism underlying the Kv2.1-mediated β-cell apoptosis is obscure. Here, the small molecular compound, ethyl 5-(3-ethoxy-4-methoxyphenyl)-2-(4-hydroxy-3-methoxybenzylidene)-7-methyl-3-oxo-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate (SP6616) was discovered to be a new Kv2.1 inhibitor. It was effective in both promoting GSIS and protecting β cells from apoptosis. Evaluation of SP6616 on either high-fat diet combined with streptozocin-induced type 2 diabetic mice or db/db mice further verified its efficacy in the amelioration of β-cell dysfunction and glucose homeostasis. SP6616 treatment efficiently increased serum insulin level, restored β-cell mass, decreased fasting blood glucose and glycated hemoglobin levels, and improved oral glucose tolerance. Mechanism study indicated that the promotion of SP6616 on β-cell survival was tightly linked to its regulation against both protein kinases C (PKC)/extracellular-regulated protein kinases 1/2 (Erk1/2) and calmodulin(CaM)/phosphatidylinositol 3-kinase(PI3K)/serine/threonine-specific protein kinase (Akt) signaling pathways. To our knowledge, this may be the first report on the underlying pathway responsible for the Kv2.1-mediated β-cell protection. In addition, our study has also highlighted the potential of SP6616 in the treatment of type 2 diabetes.

  8. Overexpressed DNA polymerase iota regulated by JNK/c-Jun contributes to hypermutagenesis in bladder cancer.

    PubMed

    Yuan, Fang; Xu, Zhigang; Yang, Mingzhen; Wei, Quanfang; Zhang, Yi; Yu, Jin; Zhi, Yi; Liu, Yang; Chen, Zhiwen; Yang, Jin

    2013-01-01

    Human DNA polymerase iota (pol ι) possesses high error-prone DNA replication features and performs translesion DNA synthesis. It may be specialized and strictly regulated in normal mammalian cells. Dysregulation of pol ι may contribute to the acquisition of a mutator phenotype. However, there are few reports describing the transcription regulatory mechanism of pol ι, and there is controversy regarding its role in carcinogenesis. In this study, we performed the deletion and point-mutation experiment, EMSA, ChIP, RNA interference and western blot assay to prove that c-Jun activated by c-Jun N-terminal kinase (JNK) regulates the transcription of pol ι in normal and cancer cells. Xeroderma pigmentosum group C protein (XPC) and ataxia-telangiectasia mutated related protein (ATR) promote early JNK activation in response to DNA damage and consequently enhance the expression of pol ι, indicating that the novel role of JNK signal pathway is involved in DNA damage response. Furthermore, associated with elevated c-Jun activity, the overexpression of pol ι is positively correlated with the clinical tumor grade in 97 bladder cancer samples and may contribute to the hypermutagenesis. The overexpressed pol ι-involved mutagenesis is dependent on JNK/c-Jun pathway in bladder cancer cells identifying by the special mutation spectra. Our results support the conclusion that dysregulation of pol ι by JNK/c-Jun is involved in carcinogenesis and offer a novel understanding of the role of pol ι or c-Jun in mutagenesis.

  9. Overexpressed DNA Polymerase Iota Regulated by JNK/c-Jun Contributes to Hypermutagenesis in Bladder Cancer

    PubMed Central

    Yuan, Fang; Xu, Zhigang; Yang, Mingzhen; Wei, Quanfang; Zhang, Yi; Yu, Jin; Zhi, Yi; Liu, Yang; Chen, Zhiwen; Yang, Jin

    2013-01-01

    Human DNA polymerase iota (pol ι) possesses high error-prone DNA replication features and performs translesion DNA synthesis. It may be specialized and strictly regulated in normal mammalian cells. Dysregulation of pol ι may contribute to the acquisition of a mutator phenotype. However, there are few reports describing the transcription regulatory mechanism of pol ι, and there is controversy regarding its role in carcinogenesis. In this study, we performed the deletion and point-mutation experiment, EMSA, ChIP, RNA interference and western blot assay to prove that c-Jun activated by c-Jun N-terminal kinase (JNK) regulates the transcription of pol ι in normal and cancer cells. Xeroderma pigmentosum group C protein (XPC) and ataxia-telangiectasia mutated related protein (ATR) promote early JNK activation in response to DNA damage and consequently enhance the expression of pol ι, indicating that the novel role of JNK signal pathway is involved in DNA damage response. Furthermore, associated with elevated c-Jun activity, the overexpression of pol ι is positively correlated with the clinical tumor grade in 97 bladder cancer samples and may contribute to the hypermutagenesis. The overexpressed pol ι-involved mutagenesis is dependent on JNK/c-Jun pathway in bladder cancer cells identifying by the special mutation spectra. Our results support the conclusion that dysregulation of pol ι by JNK/c-Jun is involved in carcinogenesis and offer a novel understanding of the role of pol ι or c-Jun in mutagenesis. PMID:23922701

  10. O-GlcNAc modification of Sp1 mediates hyperglycaemia-induced ICAM-1 up-regulation in endothelial cells.

    PubMed

    Zhang, Yuan; Qu, Yuan; Niu, Tian; Wang, Haiyan; Liu, Kun

    2017-02-26

    Intracellular adhesion molecule 1 (ICAM-1) is an important inflammatory factor that causes retinal damage during diabetic retinopathy. Hyperglycaemia can increase ICAM-1 expression in endothelial cells and the ICAM-1 promoter is responsive to the transcription factor specificity protein 1 (Sp1). O-GlcNAc modification is driven by the glucose concentration and has a profound effect on Sp1 activity. In this study, we investigated the underlying mechanism through which hyperglycaemia triggers ICAM-1 expression, which is mediated by O-GlcNAc modification of Sp1 in human umbilical vein endothelial cells (HUVECs) and rat retinal capillary endothelial cells (RRCECs). We showed that hyperglycaemia (30 mM) increased ICAM-1 expression compared to control conditions (5 mM). The addition of an OGT inhibitor decreased ICAM-1 expression and addition of an OGA inhibitor enhanced ICAM-1 expression. Furthermore, cells transduced with siSp1 exhibited dramatically decreased ICAM-1 expression. These results proved that the up-regulation of ICAM-1 with hyperglycaemia is mediated by O-GlcNAc modification of Sp1. It helps to explain the mechanism of ICAM-1 processing in HUVECs and RRCECs. Understanding how this inflammatory factor is modulated during diabetic retinopathy will ultimately help to design novel therapeutics to treat this condition. Copyright © 2017. Published by Elsevier Inc.

  11. c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Sclerosis

    DTIC Science & Technology

    2015-03-01

    1 AWARD NUMBER: W81XWH-12-1-0431 TITLE: “c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Sclerosis ” PRINCIPAL...TITLE AND SUBTITLE “c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Scelerosis” 5a. CONTRACT NUMBER 5b. GRANT NUMBER... Lateral   Sclerosis ”   Final  Report:  Project  Period  Sept  2012-­‐Dec  2014     Personnel  List:     Feng,  Yangbo

  12. Specific detection of Mycobacterium sp. genomic DNA using dual labeled gold nanoparticle based electrochemical biosensor.

    PubMed

    Thiruppathiraja, Chinnasamy; Kamatchiammal, Senthilkumar; Adaikkappan, Periyakaruppan; Santhosh, Devakirubakaran Jayakar; Alagar, Muthukaruppan

    2011-10-01

    The present study was aimed at the development and evaluation of a DNA electrochemical biosensor for Mycobacterium sp. genomic DNA detection in a clinical specimen using a signal amplifier as dual-labeled AuNPs. The DNA electrochemical biosensors were fabricated using a sandwich detection strategy involving two kinds of DNA probes specific to Mycobacterium sp. genomic DNA. The probes of enzyme ALP and the detector probe both conjugated on the AuNPs and subsequently hybridized with target DNA immobilized in a SAM/ITO electrode followed by characterization with CV, EIS, and DPV analysis using the electroactive species para-nitrophenol generated by ALP through hydrolysis of para-nitrophenol phosphate. The effect of enhanced sensitivity was obtained due to the AuNPs carrying numerous ALPs per hybridization and a detection limit of 1.25 ng/ml genomic DNA was determined under optimized conditions. The dual-labeled AuNP-facilitated electrochemical sensor was also evaluated by clinical sputum samples, showing a higher sensitivity and specificity and the outcome was in agreement with the PCR analysis. In conclusion, the developed electrochemical sensor demonstrated unique sensitivity and specificity for both genomic DNA and sputum samples and can be employed as a regular diagnostics tool for Mycobacterium sp. monitoring in clinical samples. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Cigarette smoke disrupts the integrity of airway adherens junctions through the aberrant interaction of p120-catenin with the cytoplasmic tail of MUC1

    PubMed Central

    Zhang, Lili; Gallup, Marianne; Zlock, Lorna; Basbaum, Carol; Finkbeiner, Walter E.; McNamara, Nancy A.

    2014-01-01

    Adherens junctions (AJs) containing epithelial cadherin (E-cad) bound to p120-catenin (p120ctn) and β-catenin (β-ctn) play a crucial role in regulating cell–cell adhesion. Cigarette smoke abrogates cell–cell adhesion between epithelial cells by disrupting E-cad, a hallmark of epithelial–mesenchymal transition (EMT), yet the underlying mechanism remains unknown. We used an organotypic culture of primary human bronchial epithelial (HBE) cells treated with smoke-concentrated medium (Smk) to establish an essential role for the interaction between p120ctn and the cytoplasmic tail of MUC1 (MUC1-CT) in regulating E-cad disruption. Within the first 4 h of smoke exposure, apical MUC1-CT repositioned to the basolateral membrane of pseudo-stratified HBE cells, where it interacted with p120ctn. A time-dependent increase in MUC1-CT/p120ctn complexes occurred in conjunction with a time-dependent dissociation of p120ctn/E-cad/β-ctn complexes, as well as the coordinated degradation of p120ctn and E-cad. Interestingly, Smk induced a similar interaction between MUC1-CT and β-ctn, but this occurred 44 h after MUC1-CT’s initial interaction with p120ctn, and well after the AJs were destroyed. Blocking MUC1-CT’s interaction with p120ctn using a MUC1-CT dominant-negative peptide, PMIP, successfully abolished Smk’s disruptive effects on AJs and recovered apical-basolateral polarity of HBE cells. The MUC1-CT/p120ctn interaction was highly dependent on EGFR/Src/Jnk-mediated tyrosine phosphorylation (TyrP) of MUC1-CT. Accordingly, EGFR, Src or Jnk inhibitors (AG1478, PP2, SP600125, respectively) abrogated Smk-induced MUC1-CT-TyrP, MUC1-CT/p120ctn interaction, AJ disruption, and loss of cellular polarity. Our work identified MUC1-CT and p120ctn as important regulators of epithelial polarity and cell-cell adhesion during a smoke-induced EMT-like process. Novel therapeutics designed to inhibit MUC1-CT/p120ctn complex formation may prevent EMT in the smoker’s airway. PMID

  14. SCF/C-Kit/JNK/AP-1 Signaling Pathway Promotes Claudin-3 Expression in Colonic Epithelium and Colorectal Carcinoma.

    PubMed

    Wang, Yaxi; Sun, Tingyi; Sun, Haimei; Yang, Shu; Li, Dandan; Zhou, Deshan

    2017-04-06

    Claudin-3 is a major protein of tight junctions (TJs) in the intestinal epithelium and is critical for maintaining cell-cell adhesion, barrier function, and epithelium polarity. Recent studies have shown high claudin-3 levels in several solid tumors, but the regulation mechanism of claudin-3 expression remains poorly understood. In the present study, colorectal cancer (CRC) tissues, HT-29 and DLD-1 CRC cell lines, CRC murine model (C57BL/6 mice) and c-kit loss-of-function mutant mice were used. We demonstrated that elevated claudin-3 levels were positively correlated with highly expressed c-kit in CRC tissues based upon analysis of protein expression. In vitro, claudin-3 expression was clearly increased in CRC cells by overexpressed c-kit or stimulated by exogenous recombinant human stem cell factor (rhSCF), while significantly decreased by the treatment with c-kit or c-Jun N-terminal kinase (JNK) inhibitors. Chromatin immunoprecipitation (ChIP) and luciferase reporter assay showed that SCF/c-kit signaling significantly promoted activator protein-1 (AP-1) binding with CLDN-3 promoter and enhanced its transcription activity. Furthermore, decreased expression of claudin-3 was obtained in the colonic epithelium from the c-Kit loss-of-function mutant mice. In conclusion, SCF/c-kit-JNK/AP-1 signaling pathway significantly promoted claudin-3 expression in colonic epithelium and CRC, which could contribute to epithelial barrier function maintenance and to CRC development.

  15. Sp1 and Sp3 Are the Transcription Activators of Human ek1 Promoter in TSA-Treated Human Colon Carcinoma Cells.

    PubMed

    Kuan, Chee Sian; See Too, Wei Cun; Few, Ling Ling

    2016-01-01

    Ethanolamine kinase (EK) catalyzes the phosphorylation of ethanolamine, the first step in the CDP-ethanolamine pathway for the biosynthesis of phosphatidylethanolamine (PE). Human EK exists as EK1, EK2α and EK2β isoforms, encoded by two separate genes, named ek1 and ek2. EK activity is stimulated by carcinogens and oncogenes, suggesting the involvement of EK in carcinogenesis. Currently, little is known about EK transcriptional regulation by endogenous or exogenous signals, and the ek gene promoter has never been studied. In this report, we mapped the important regulatory regions in the human ek1 promoter. 5' deletion analysis and site-directed mutagenesis identified a Sp site at position (-40/-31) that was essential for the basal transcription of this gene. Treatment of HCT116 cells with trichostatin A (TSA), a histone deacetylase inhibitor, significantly upregulated the ek1 promoter activity through the Sp(-40/-31) site and increased the endogenous expression of ek1. Chromatin immunoprecipitation assay revealed that TSA increased the binding of Sp1, Sp3 and RNA polymerase II to the ek1 promoter in HCT116 cells. The effect of TSA on ek1 promoter activity was cell-line specific as TSA treatment did not affect ek1 promoter activity in HepG2 cells. In conclusion, we showed that Sp1 and Sp3 are not only essential for the basal transcription of the ek1 gene, their accessibility to the target site on the ek1 promoter is regulated by histone protein modification in a cell line dependent manner.

  16. Reversion of apoptotic resistance of TP53-mutated Burkitt lymphoma B-cells to spindle poisons by exogenous activation of JNK and p38 MAP kinases.

    PubMed

    Farhat, M; Poissonnier, A; Hamze, A; Ouk-Martin, C; Brion, J-D; Alami, M; Feuillard, J; Jayat-Vignoles, C

    2014-05-01

    Defects in apoptosis are frequently the cause of cancer emergence, as well as cellular resistance to chemotherapy. These phenotypes may be due to mutations of the tumor suppressor TP53 gene. In this study, we examined the effect of various mitotic spindle poisons, including the new isocombretastatin derivative isoNH2CA-4 (a tubulin-destabilizing molecule, considered to bind to the colchicine site by analogy with combretastatin A-4), on BL (Burkitt lymphoma) cells. We found that resistance to spindle poison-induced apoptosis could be reverted in tumor protein p53 (TP53)-mutated cells by EBV (Epstein Barr virus) infection. This reversion was due to restoration of the intrinsic apoptotic pathway, as assessed by relocation of the pro-apoptotic molecule Bax to mitochondria, loss of mitochondrial integrity and activation of the caspase cascade with PARP (poly ADP ribose polymerase) cleavage. EBV sensitized TP53-mutated BL cells to all spindle poisons tested, including vincristine and taxol, an effect that was systematically downmodulated by pretreatment of cells with inhibitors of p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinases. Exogenous activation of p38 and JNK pathways by dihydrosphingosine reverted resistance of TP53-mutated BL cells to spindle poisons. Dihydrosphingosine treatment of TP53-deficient Jurkat and K562 cell lines was also able to induce cell death. We conclude that activation of p38 and JNK pathways may revert resistance of TP53-mutated cells to spindle poisons. This opens new perspectives for developing alternative therapeutic strategies when the TP53 gene is inactivated.

  17. Transcription of mouse Sp2 yields alternatively spliced and sub-genomic mRNAs in a tissue- and cell-type-specific fashion.

    PubMed

    Yin, Haifeng; Nichols, Teresa D; Horowitz, Jonathan M

    2010-07-01

    The Sp-family of transcription factors is comprised by nine members, Sp1-9, that share a highly conserved DNA-binding domain. Sp2 is a poorly characterized member of this transcription factor family that is widely expressed in murine and human cell lines yet exhibits little DNA-binding or trans-activation activity in these settings. As a prelude to the generation of a "knock-out" mouse strain, we isolated a mouse Sp2 cDNA and performed a detailed analysis of Sp2 transcription in embryonic and adult mouse tissues. We report that (1) the 5' untranslated region of Sp2 is subject to alternative splicing, (2) Sp2 transcription is regulated by at least two promoters that differ in their cell-type specificity, (3) one Sp2 promoter is highly active in nine mammalian cell lines and strains and is regulated by at least five discrete stimulatory and inhibitory elements, (4) a variety of sub-genomic messages are synthesized from the Sp2 locus in a tissue- and cell-type-specific fashion and these transcripts have the capacity to encode a novel partial-Sp2 protein, and (5) RNA in situ hybridization assays indicate that Sp2 is widely expressed during mouse embryogenesis, particularly in the embryonic brain, and robust Sp2 expression occurs in neurogenic regions of the post-natal and adult brain. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  18. Propiconazole is a specific and accessible brassinosteroid (BR) biosynthesis inhibitor for Arabidopsis and maize.

    PubMed

    Hartwig, Thomas; Corvalan, Claudia; Best, Norman B; Budka, Joshua S; Zhu, Jia-Ying; Choe, Sunghwa; Schulz, Burkhard

    2012-01-01

    Brassinosteroids (BRs) are steroidal hormones that play pivotal roles during plant development. In addition to the characterization of BR deficient mutants, specific BR biosynthesis inhibitors played an essential role in the elucidation of BR function in plants. However, high costs and limited availability of common BR biosynthetic inhibitors constrain their key advantage as a species-independent tool to investigate BR function. We studied propiconazole (Pcz) as an alternative to the BR inhibitor brassinazole (Brz). Arabidopsis seedlings treated with Pcz phenocopied BR biosynthetic mutants. The steady state mRNA levels of BR, but not gibberellic acid (GA), regulated genes increased proportional to the concentrations of Pcz. Moreover, root inhibition and Pcz-induced expression of BR biosynthetic genes were rescued by 24epi-brassinolide, but not by GA(3) co-applications. Maize seedlings treated with Pcz showed impaired mesocotyl, coleoptile, and true leaf elongation. Interestingly, the genetic background strongly impacted the tissue specific sensitivity towards Pcz. Based on these findings we conclude that Pcz is a potent and specific inhibitor of BR biosynthesis and an alternative to Brz. The reduced cost and increased availability of Pcz, compared to Brz, opens new possibilities to study BR function in larger crop species.

  19. Inhibitors of biofilm formation by biofuel fermentation contaminants.

    PubMed

    Leathers, Timothy D; Bischoff, Kenneth M; Rich, Joseph O; Price, Neil P J; Manitchotpisit, Pennapa; Nunnally, Melinda S; Anderson, Amber M

    2014-10-01

    Biofuel fermentation contaminants such as Lactobacillus sp. may persist in production facilities by forming recalcitrant biofilms. In this study, biofilm-forming strains of Lactobacillus brevis, Lactobacillus fermentum, and Lactobacillus plantarum were isolated and characterized from a dry-grind fuel ethanol plant. A variety of potential biofilm inhibitors were tested, including microbial polysaccharides, commercial enzymes, ferric ammonium citrate, liamocins, phage endolysin, xylitol, and culture supernatants from Bacillus sp. A commercial enzyme mixture (Novozyme 188) and culture supernatants from Bacillus subtilis strains ALT3A and RPT-82412 were identified as the most promising biofilm inhibitors. In biofilm flow cells, these inhibitors reduced the density of viable biofilm cells by 0.8-0.9 log cfu/cm(2). Unlike B. subtilis strain RPT-82412, B. subtilis strain ALT3A and Novozyme 188 did not inhibit planktonic growth of Lactobacillus sp. MALDI-TOF mass spectra showed the production of surfactin-like molecules by both B. subtilis strains, and the coproduction of iturin-like molecules by strain RPT-82412. Published by Elsevier Ltd.

  20. Salmonella enteritidis Effector AvrA Stabilizes Intestinal Tight Junctions via the JNK Pathway.

    PubMed

    Lin, Zhijie; Zhang, Yong-Guo; Xia, Yinglin; Xu, Xiulong; Jiao, Xinan; Sun, Jun

    2016-12-23

    Salmonella pathogenesis studies to date have focused on Salmonella typhimurium, and the pathogenesis of a second major serotype, Salmonella enteritidis, is poorly understood. Salmonella spp. possess effector proteins that display biochemical activities and modulate host functions. Here, we generated a deletion mutant of the effector AvrA, S.E-AvrA - , and a plasmid-mediated complementary strain, S.E-AvrA - /pAvrA + (S.E-AvrA + ), in S. Enteritidis. Using in vitro and in vivo infection models, we showed that AvrA stabilizes epithelial tight junction (TJ) proteins, such as ZO-1, in human intestinal epithelial cells. Transepithelial electrical resistance was significantly higher in cells infected with S.E-AvrA + than in cells infected with S.E-AvrA - Inhibition of the JNK pathway suppresses the disassembly of TJ proteins; we found that enteritidis AvrA inhibited JNK activity in cells infected with wild type or S.E-AvrA + strains. Therefore, Enteritidis AvrA-induced ZO-1 stability is achieved via suppression of the JNK pathway. Furthermore, the S.E-AvrA - strain led to enhanced bacterial invasion, both in vitro and in vivo Taken together, our data reveal a novel role for AvrA in S. Enteritidis: Enteritidis AvrA stabilizes intestinal TJs and attenuates bacterial invasion. The manipulation of JNK activity and TJs in microbial-epithelial interactions may be a novel therapeutic approach for the treatment of infectious diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.