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Sample records for activating p38 mapk

  1. p38γ and p38δ Mitogen Activated Protein Kinases (MAPKs), New Stars in the MAPK Galaxy.

    PubMed

    Escós, Alejandra; Risco, Ana; Alsina-Beauchamp, Dayanira; Cuenda, Ana

    2016-01-01

    The protein kinases p38γ and p38δ belong to the p38 mitogen-activated protein kinase (MAPK) family. p38MAPK signaling controls many cellular processes and is one of the most conserved mechanisms in eukaryotes for the cellular response to environmental stress and inflammation. Although p38γ and p38δ are widely expressed, it is likely that they perform specific functions in different tissues. Their involvement in human pathologies such as inflammation-related diseases or cancer is starting to be uncovered. In this article we give a general overview and highlight recent advances made in defining the functions of p38γ and p38δ, focusing in innate immunity and inflammation. We consider the potential of the pharmacological targeting of MAPK pathways to treat autoimmune and inflammatory diseases and cancer. PMID:27148533

  2. p38γ and p38δ Mitogen Activated Protein Kinases (MAPKs), New Stars in the MAPK Galaxy

    PubMed Central

    Escós, Alejandra; Risco, Ana; Alsina-Beauchamp, Dayanira; Cuenda, Ana

    2016-01-01

    The protein kinases p38γ and p38δ belong to the p38 mitogen-activated protein kinase (MAPK) family. p38MAPK signaling controls many cellular processes and is one of the most conserved mechanisms in eukaryotes for the cellular response to environmental stress and inflammation. Although p38γ and p38δ are widely expressed, it is likely that they perform specific functions in different tissues. Their involvement in human pathologies such as inflammation-related diseases or cancer is starting to be uncovered. In this article we give a general overview and highlight recent advances made in defining the functions of p38γ and p38δ, focusing in innate immunity and inflammation. We consider the potential of the pharmacological targeting of MAPK pathways to treat autoimmune and inflammatory diseases and cancer. PMID:27148533

  3. Dehydrocorydaline promotes myogenic differentiation via p38 MAPK activation

    PubMed Central

    Yoo, Miran; Lee, Sang-Jin; Kim, Yong Kee; Seo, Dong-Wan; Baek, Nam-In; Ryu, Jae-Ha; Kang, Jong-Sun; Bae, Gyu-Un

    2016-01-01

    Muscle regeneration is a coordinated process that involves proliferation and differentiation of muscle progenitor cells. Activation of MyoD is a key event in myogenic differentiation, which is regulated by p38 mitogen-activated protein kinases (MAPK). In a screen of natural compounds for the enhancement of MyoD activity, dehydrocorydaline (DHC) from the Corydalis tuber was identified. Treatment of C2C12 myoblasts with DHC increased the expression levels of muscle-specific proteins, including MyoD, myogenin and myosin heavy chain. In addition, C2C12 myoblasts exhibited enhanced multinucleated myotube formation without any cytotoxicity. Treatment with DHC elevated p38 MAPK activation and the interaction of MyoD with an E protein, which is likely to result in activation of MyoD and promotion of myoblast differentiation. Furthermore, defects in differentiation-induced p38 MAPK activation and myoblast differentiation induced by depletion of the promyogenic receptor protein Cdo in C2C12 myoblasts were restored by DHC treatment. In conclusion, these results indicated that DHC stimulates p38 MAPK activation, which can enhance heterodimerization of MyoD and E proteins, thus resulting in MyoD activation and myoblast differentiation. These findings suggested that DHC may be considered a potential therapeutic compound for the improvement of muscle stem cell regenerative capacity in injured muscle. PMID:27573543

  4. Kappa Opioid Receptor-Induced Aversion Requires p38 MAPK Activation in VTA Dopamine Neurons

    PubMed Central

    Ehrich, Jonathan M.; Messinger, Daniel I.; Knakal, Cerise R.; Kuhar, Jamie R.; Schattauer, Selena S.; Bruchas, Michael R.; Zweifel, Larry S.; Kieffer, Brigitte L.; Phillips, Paul E.M.

    2015-01-01

    The endogenous dynorphin-κ opioid receptor (KOR) system encodes the dysphoric component of the stress response and controls the risk of depression-like and addiction behaviors; however, the molecular and neural circuit mechanisms are not understood. In this study, we report that KOR activation of p38α MAPK in ventral tegmental (VTA) dopaminergic neurons was required for conditioned place aversion (CPA) in mice. Conditional genetic deletion of floxed KOR or floxed p38α MAPK by Cre recombinase expression in dopaminergic neurons blocked place aversion to the KOR agonist U50,488. Selective viral rescue by wild-type KOR expression in dopaminergic neurons of KOR−/− mice restored U50,488-CPA, whereas expression of a mutated form of KOR that could not initiate p38α MAPK activation did not. Surprisingly, while p38α MAPK inactivation blocked U50,488-CPA, p38α MAPK was not required for KOR inhibition of evoked dopamine release measured by fast scan cyclic voltammetry in the nucleus accumbens. In contrast, KOR activation acutely inhibited VTA dopaminergic neuron firing, and repeated exposure attenuated the opioid response. This adaptation to repeated exposure was blocked by conditional deletion of p38α MAPK, which also blocked KOR-induced tyrosine phosphorylation of the inwardly rectifying potassium channel (GIRK) subunit Kir3.1 in VTA dopaminergic neurons. Consistent with the reduced response, GIRK phosphorylation at this amino terminal tyrosine residue (Y12) enhances channel deactivation. Thus, contrary to prevailing expectations, these results suggest that κ opioid-induced aversion requires regulation of VTA dopaminergic neuron somatic excitability through a p38α MAPK effect on GIRK deactivation kinetics rather than by presynaptically inhibiting dopamine release. SIGNIFICANCE STATEMENT Kappa opioid receptor (KOR) agonists have the potential to be effective, nonaddictive analgesics, but their therapeutic utility is greatly limited by adverse effects on mood

  5. Dehydrocorydaline promotes myogenic differentiation via p38 MAPK activation.

    PubMed

    Yoo, Miran; Lee, Sang-Jin; Kim, Yong Kee; Seo, Dong-Wan; Baek, Nam-In; Ryu, Jae-Ha; Kang, Jong-Sun; Bae, Gyu-Un

    2016-10-01

    Muscle regeneration is a coordinated process that involves proliferation and differentiation of muscle progenitor cells. Activation of MyoD is a key event in myogenic differentiation, which is regulated by p38 mitogen‑activated protein kinases (MAPK). In a screen of natural compounds for the enhancement of MyoD activity, dehydrocorydaline (DHC) from the Corydalis tuber was identified. Treatment of C2C12 myoblasts with DHC increased the expression levels of muscle‑specific proteins, including MyoD, myogenin and myosin heavy chain. In addition, C2C12 myoblasts exhibited enhanced multinucleated myotube formation without any cytotoxicity. Treatment with DHC elevated p38 MAPK activation and the interaction of MyoD with an E protein, which is likely to result in activation of MyoD and promotion of myoblast differentiation. Furthermore, defects in differentiation‑induced p38 MAPK activation and myoblast differentiation induced by depletion of the promyogenic receptor protein Cdo in C2C12 myoblasts were restored by DHC treatment. In conclusion, these results indicated that DHC stimulates p38 MAPK activation, which can enhance heterodimerization of MyoD and E proteins, thus resulting in MyoD activation and myoblast differentiation. These findings suggested that DHC may be considered a potential therapeutic compound for the improvement of muscle stem cell regenerative capacity in injured muscle.

  6. Dehydrocorydaline promotes myogenic differentiation via p38 MAPK activation.

    PubMed

    Yoo, Miran; Lee, Sang-Jin; Kim, Yong Kee; Seo, Dong-Wan; Baek, Nam-In; Ryu, Jae-Ha; Kang, Jong-Sun; Bae, Gyu-Un

    2016-10-01

    Muscle regeneration is a coordinated process that involves proliferation and differentiation of muscle progenitor cells. Activation of MyoD is a key event in myogenic differentiation, which is regulated by p38 mitogen‑activated protein kinases (MAPK). In a screen of natural compounds for the enhancement of MyoD activity, dehydrocorydaline (DHC) from the Corydalis tuber was identified. Treatment of C2C12 myoblasts with DHC increased the expression levels of muscle‑specific proteins, including MyoD, myogenin and myosin heavy chain. In addition, C2C12 myoblasts exhibited enhanced multinucleated myotube formation without any cytotoxicity. Treatment with DHC elevated p38 MAPK activation and the interaction of MyoD with an E protein, which is likely to result in activation of MyoD and promotion of myoblast differentiation. Furthermore, defects in differentiation‑induced p38 MAPK activation and myoblast differentiation induced by depletion of the promyogenic receptor protein Cdo in C2C12 myoblasts were restored by DHC treatment. In conclusion, these results indicated that DHC stimulates p38 MAPK activation, which can enhance heterodimerization of MyoD and E proteins, thus resulting in MyoD activation and myoblast differentiation. These findings suggested that DHC may be considered a potential therapeutic compound for the improvement of muscle stem cell regenerative capacity in injured muscle. PMID:27573543

  7. Molecular Changes Involving MEK3-p38 MAPK Activation in Chronic Masticatory Myalgia.

    PubMed

    Meng, H; Gao, Y; Kang, Y F; Zhao, Y P; Yang, G J; Wang, Y; Cao, Y; Gan, Y H; Xie, Q F

    2016-09-01

    The exact mechanism underlying chronic masticatory myalgia (CMM), a conspicuous symptom in temporomandibular disorders, remains unclear. This investigation compared gene expression profiles between CMM patients and healthy subjects. Peripheral blood leukocytes were collected in 8 cases and 8 controls and subjected to whole genome microarray analyses. Data were analyzed with Gene Ontology and interactive pathways analyses. According to Gene Ontology analysis, categories such as ion transport, response to stimuli, and metabolic process were upregulated. The pathway analysis suggested overexpression of the mitogen-activated protein kinase (MAPK) pathway in CMM patients and to a higher degree in a pathway network. Overexpression of representative members of the MAPK pathway-including MAPK kinase 3 (MEK3), calcium voltage-gated channel auxiliary subunit gamma 2 (CACNG2), and growth arrest and DNA damage-inducible gamma (GADD45G)-was validated with real-time polymerase chain reaction. The upregulation of MEK3 was negatively correlated with the age of the CMM group. In the next step, the authors focused on MEK3, the gene that exhibited the greatest degree of differential expression, and its downstream target protein p38 MAPK. The results revealed upregulation of MEK3, as well as phosphorylated MEK3 and phosphorylated p38 MAPK, in CMM patients. These results provide a "fingerprint" for mechanistic studies of CMM in the future and highlight the importance of MEK3-p38 MAPK activation in CMM. PMID:27418173

  8. Activated p38 MAPK in Peripheral Blood Monocytes of Steroid Resistant Asthmatics

    PubMed Central

    Li, Ling-bo; Leung, Donald Y. M.; Goleva, Elena

    2015-01-01

    Steroid resistance is a significant problem in management of chronic inflammatory diseases, including asthma. Accessible biomarkers are needed to identify steroid resistant patients to optimize their treatment. This study examined corticosteroid resistance in severe asthma. 24 asthmatics with forced expiratory volume in one second of less then 80% predicted were classified as steroid resistant or steroid sensitive based on changes in their lung function following a week of treatment with oral prednisone. Heparinised blood was collected from patients prior to oral prednisone administration. Phosphorylated mitogen activated kinases (MAPK) (extracellular regulated kinase (ERK), p38 and jun kinase (JNK)) were analyzed in whole blood samples using flow cytometry. Activation of phospho-p38 MAPK and phospho-mitogen- and stress-activated protein kinase 1 (MSK1) in asthmatics’ peripheral blood mononuclear cells (PBMC) were confirmed by Western blot. Dexamethasone suppression of the LPS-induced IL-8 mRNA production by steroid resistant asthmatics PBMC in the presence of p38 and ERK inhibitors was evaluated by real time PCR. Flow cytometry analysis identified significantly stronger p38 phosphorylation in CD14+ monocytes from steroid resistant than steroid sensitive asthmatics (p = 0.014), whereas no difference was found in phosphorylation of ERK or JNK in CD14+ cells from these two groups of asthmatics. No difference in phosphorylated p38, ERK, JNK was detected in CD4+, CD8+ T cells, B cells and NK cells from steroid resistant vs. steroid sensitive asthmatics. P38 MAPK pathway activation was confirmed by Western blot, as significantly higher phospho-p38 and phospho-MSK1 levels were detected in the PBMC lysates from steroid resistant asthmatics. P38 inhibitor significantly enhanced DEX suppression of LPS-induced IL-8 mRNA by PBMC of steroid resistant asthmatics. This is the first report demonstrating selective p38 MAPK pathway activation in blood monocytes of steroid

  9. p38 mitogen-activated protein kinase (p38 MAPK)-mediated autoimmunity: lessons to learn from ANCA vasculitis and pemphigus vulgaris.

    PubMed

    Mavropoulos, Athanasios; Orfanidou, Timoklia; Liaskos, Christos; Smyk, Daniel S; Billinis, Charalambos; Blank, Miri; Rigopoulou, Eirini I; Bogdanos, Dimitrios P

    2013-03-01

    Evidence is beginning to accumulate that p38 mitogen activated protein kinase (p38 MAPK) signaling pathway plays an important role in the regulation of cellular and humoral autoimmune responses. The exact mechanisms and the degree by which the p38 MAPK pathway participates in the immune-mediated induction of diseases have started to emerge. This review discusses the recent advances in the molecular dissection of the p38 MAPK pathway and the findings generated by reports investigating its role in the pathogenesis of autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and autoimmune hepatitis. Application of newly-developed protocols based on sensitive flow cytometric detection has proven to be a useful tool in the investigation of the phosphorylation of p38 MAPK within different peripheral blood mononuclear cell populations and may help us to better understand the enigmatic role of this signaling cascade in the induction of autoimmunity as well as its role in immunosuppressive-induced remission. Special attention is paid to reported data proposing a specific role for autoantibody-induced activation of p38 MAPK-mediated immunopathology in the pathogenesis of autoimmune blistering diseases and anti-neutrophilic antibody-mediated vasculitides.

  10. Neferine induces autophagy of human ovarian cancer cells via p38 MAPK/ JNK activation.

    PubMed

    Xu, Limei; Zhang, Xiyu; Li, Yinuo; Lu, Shuhua; Lu, Shan; Li, Jieyin; Wang, Yuqiong; Tian, Xiaoxue; Wei, Jian-Jun; Shao, Changshun; Liu, Zhaojian

    2016-07-01

    Ovarian cancer is the most lethal gynecological malignancy. Patients usually have poor prognosis because of late diagnosis, relapse, and chemoresistance. It is pressing to seek novel agent for the treatment of ovarian cancer. Neferine is a bisbenzylisoquinoline alkaloid isolated from the embryos of lotus (Nelumbo nucifera). In this study, we investigated the antitumor effect of neferine on ovarian cancer cells. We found that neferine exhibited growth-inhibitory effect on human ovarian cancer cells, whereas showing less cytotoxic to non-malignant fallopian tube epithelial cells. Furthermore, we demonstrated that neferine induced autophagy and inactivated the mTOR pathway. Finally, we found that both p38 MAPK and JNK signaling pathways were activated by neferine treatment and contributed to the induction of autophagy in ovarian cancer cells. In conclusion, our findings showed that neferine induced autophagy of human ovarian cancer cells via p38 MAPK/JNK activation. Neferine may be explored as a promising antitumoral agent in ovarian cancer. PMID:26738868

  11. PKC theta and p38 MAPK activate the EBV lytic cycle through autophagy induction.

    PubMed

    Gonnella, Roberta; Granato, Marisa; Farina, Antonella; Santarelli, Roberta; Faggioni, Alberto; Cirone, Mara

    2015-07-01

    PKC activation by combining TPA with sodium butyrate (T/B) represents the most effective and widely used strategy to induce the Epstein-Barr virus (EBV) lytic cycle. The results obtained in this study show that novel PKCθ is involved in such process and that it acts through the activation of p38 MAPK and autophagy induction. Autophagy, a mechanism of cellular defense in stressful conditions, is manipulated by EBV to enhance viral replication. Besides promoting the EBV lytic cycle, the activation of p38 and autophagy resulted in a pro-survival effect, as indicated by p38 or ATG5 knocking down experiments. However, this pro-survival role was counteracted by a pro-death activity of PKCθ, due to the dephosphorylation of AKT. In conclusion, this study reports, for the first time, that T/B activates a PKCθ-p38 MAPK axis in EBV infected B cells, that promotes the viral lytic cycle and cell survival and dephosphorylates AKT, balancing cell life and cell death. PMID:25827954

  12. PKC theta and p38 MAPK activate the EBV lytic cycle through autophagy induction.

    PubMed

    Gonnella, Roberta; Granato, Marisa; Farina, Antonella; Santarelli, Roberta; Faggioni, Alberto; Cirone, Mara

    2015-07-01

    PKC activation by combining TPA with sodium butyrate (T/B) represents the most effective and widely used strategy to induce the Epstein-Barr virus (EBV) lytic cycle. The results obtained in this study show that novel PKCθ is involved in such process and that it acts through the activation of p38 MAPK and autophagy induction. Autophagy, a mechanism of cellular defense in stressful conditions, is manipulated by EBV to enhance viral replication. Besides promoting the EBV lytic cycle, the activation of p38 and autophagy resulted in a pro-survival effect, as indicated by p38 or ATG5 knocking down experiments. However, this pro-survival role was counteracted by a pro-death activity of PKCθ, due to the dephosphorylation of AKT. In conclusion, this study reports, for the first time, that T/B activates a PKCθ-p38 MAPK axis in EBV infected B cells, that promotes the viral lytic cycle and cell survival and dephosphorylates AKT, balancing cell life and cell death.

  13. Cadmium induces vascular permeability via activation of the p38 MAPK pathway

    SciTech Connect

    Dong, Fengyun; Guo, Fang; Li, Liqun; Guo, Ling; Hou, Yinglong; Hao, Enkui; Yan, Suhua; Allen, Thaddeus D.; Liu, Ju

    2014-07-18

    Highlights: • Low-dose cadmium (Cd) induces vascular hyper-permeability. • p38 MAPK mediates Cd-induced disruption of endothelial cell barrier function. • SB203850 inhibits Cd-induced membrane dissociation of VE-cadherin and β-catenin. • SB203850 reduces Cd-induced expression and secretion of TNF-α. - Abstract: The vasculature of various organs is a targeted by the environmental toxin, cadmium (Cd). However, mechanisms leading to pathological conditions are poorly understood. In the present study, we examined the effect of cadmium chloride (CdCl{sub 2}) on human umbilical vein endothelial cells (HUVECs). At 4 μM, CdCl{sub 2} induced a hyper-permeability defect in HUVECs, but not the inhibition of cell growth up to 24 h. This effect of CdCl{sub 2} was dependent on the activation of the p38 mitogen-activated protein kinase (MAPK) pathway. The p38 MAPK inhibitor SB203850 suppressed the CdCl{sub 2}-induced alteration in trans-endothelial electrical resistance in HUVEC monolayers, a model measurement of vascular endothelial barrier integrity. SB203850 also inhibited the Cd-induced membrane dissociation of vascular endothelial (VE) cadherin and β-catenin, the important components of the adherens junctional complex. In addition, SB203850 reduces the Cd-induced expression and secretion of tumor necrosis factor α (TNF-α). Taken together, our findings suggest that Cd induces vascular hyper-permeability and disruption of endothelial barrier integrity through stimulation of p38 MAPK signaling.

  14. Involvement of p38 MAPK in the Anticancer Activity of Cultivated Cordyceps militaris.

    PubMed

    Chou, Shang-Min; Lai, Wan-Jung; Hong, Tzuwen; Tsai, Sheng-Hong; Chen, Yen-Hsun; Kao, Cheng-Hsiang; Chu, Richard; Shen, Tang-Long; Li, Tsai-Kun

    2015-01-01

    Cordyceps militaris is a traditional Chinese medicine frequently used for tonic and therapeutic purposes. Reports from our laboratory and others have demonstrated that extracts of the cultivated fruiting bodies of C. militaris (CM) exhibit a potent cytotoxic effect against many cancer cell lines, especially human leukemia cells. Here, we further investigated the underlying mechanism through which CM is cytotoxic to cancer cells. The CM-mediated induction of PARP cleavage and its related DNA damage signal (γH2AX) was diminished by caspase inhibitor I. In contrast, a ROS scavenger failed to prevent CM-mediated leukemia cell death. Moreover, two signaling molecules, AKT and p38 MAPK, were activated during the course of apoptosis induction. Employing MTT analysis, we found that a p38 MAPK inhibitor but not an AKT inhibitor could rescue cells from CM-mediated cell death, as well as inhibit the cleavage of PARP, formation of apoptotic bodies and up-regulation of the γH2AX signal. These results suggest that CM-mediated leukemia cell death occurs through the activation of the p38 MAPK pathway, indicating its potential therapeutic effects against human leukemia. PMID:26205966

  15. BMP9-Induced Survival Effect in Liver Tumor Cells Requires p38MAPK Activation

    PubMed Central

    García-Álvaro, María; Addante, Annalisa; Roncero, Cesáreo; Fernández, Margarita; Fabregat, Isabel; Sánchez, Aránzazu; Herrera, Blanca

    2015-01-01

    The study of bone morphogenetic proteins (BMPs) role in tumorigenic processes, and specifically in the liver, has gathered importance in the last few years. Previous studies have shown that BMP9 is overexpressed in about 40% of hepatocellular carcinoma (HCC) patients. In vitro data have also shown evidence that BMP9 has a pro-tumorigenic action, not only by inducing epithelial to mesenchymal transition (EMT) and migration, but also by promoting proliferation and survival in liver cancer cells. However, the precise mechanisms driving these effects have not yet been established. In the present work, we deepened our studies into the intracellular mechanisms implicated in the BMP9 proliferative and pro-survival effect on liver tumor cells. In HepG2 cells, BMP9 induces both Smad and non-Smad signaling cascades, specifically PI3K/AKT and p38MAPK. However, only the p38MAPK pathway contributes to the BMP9 growth-promoting effect on these cells. Using genetic and pharmacological approaches, we demonstrate that p38MAPK activation, although dispensable for the BMP9 proliferative activity, is required for the BMP9 protective effect on serum withdrawal-induced apoptosis. These findings contribute to a better understanding of the signaling pathways involved in the BMP9 pro-tumorigenic role in liver tumor cells. PMID:26343646

  16. BMP7 retards peripheral myelination by activating p38 MAPK in Schwann cells

    PubMed Central

    Liu, Xiaoyu; Zhao, Yahong; Peng, Su; Zhang, Shuqiang; Wang, Meihong; Chen, Yeyue; Zhang, Shan; Yang, Yumin; Sun, Cheng

    2016-01-01

    Schwann cell (SC) myelination is pivotal for the proper physiological functioning of the nervous system, but the underlying molecular mechanism remains less well understood. Here, we showed that the expression of bone morphogenetic protein 7 (BMP7) inversely correlates with myelin gene expression during peripheral myelination, which suggests that BMP7 is likely a negative regulator for myelin gene expression. Our experiments further showed that the application of BMP7 attenuates the cAMP induced myelin gene expression in SCs. Downstream pathway analysis suggested that both p38 MAPK and SMAD are activated by exogenous BMP7 in SCs. The pharmacological intervention and gene silence studies revealed that p38 MAPK, not SMAD, is responsible for BMP7-mediated suppression of myelin gene expression. In addition, c-Jun, a potential negative regulator for peripheral myelination, was up-regulated by BMP7. In vivo experiments showed that BMP7 treatment greatly impaired peripheral myelination in newborn rats. Together, our results established that BMP7 is a negative regulator for peripheral myelin gene expression and that p38 MAPK/c-Jun axis might be the main downstream target of BMP7 in this process. PMID:27491681

  17. BMP7 retards peripheral myelination by activating p38 MAPK in Schwann cells.

    PubMed

    Liu, Xiaoyu; Zhao, Yahong; Peng, Su; Zhang, Shuqiang; Wang, Meihong; Chen, Yeyue; Zhang, Shan; Yang, Yumin; Sun, Cheng

    2016-08-05

    Schwann cell (SC) myelination is pivotal for the proper physiological functioning of the nervous system, but the underlying molecular mechanism remains less well understood. Here, we showed that the expression of bone morphogenetic protein 7 (BMP7) inversely correlates with myelin gene expression during peripheral myelination, which suggests that BMP7 is likely a negative regulator for myelin gene expression. Our experiments further showed that the application of BMP7 attenuates the cAMP induced myelin gene expression in SCs. Downstream pathway analysis suggested that both p38 MAPK and SMAD are activated by exogenous BMP7 in SCs. The pharmacological intervention and gene silence studies revealed that p38 MAPK, not SMAD, is responsible for BMP7-mediated suppression of myelin gene expression. In addition, c-Jun, a potential negative regulator for peripheral myelination, was up-regulated by BMP7. In vivo experiments showed that BMP7 treatment greatly impaired peripheral myelination in newborn rats. Together, our results established that BMP7 is a negative regulator for peripheral myelin gene expression and that p38 MAPK/c-Jun axis might be the main downstream target of BMP7 in this process.

  18. The activation of p38MAPK and JNK pathways in bovine herpesvirus 1 infected MDBK cells.

    PubMed

    Zhu, Liqian; Yuan, Chen; Huang, Liyuan; Ding, Xiuyan; Wang, Jianye; Zhang, Dong; Zhu, Guoqiang

    2016-01-01

    We have shown previously that BHV-1 infection activates Erk1/2 signaling. Here, we show that BHV-1 provoked an early-stage transient and late-stage sustained activation of JNK, p38MAPK and c-Jun signaling in MDBK cells. C-Jun phosphorylation was dependent on JNK. These early events were partially due to the viral entry process. Unexpectedly, reactive oxygen species were not involved in the later activation phase. Interestingly, only activated JNK facilitated the viral multiplication identified through both chemical inhibitor and siRNA. Collectively, this study provides insight into our understanding of early stages of BHV-1 infection. PMID:27590675

  19. Halofuginone inhibits NF-kappaB and p38 MAPK in activated T cells.

    PubMed

    Leiba, M; Cahalon, L; Shimoni, A; Lider, O; Zanin-Zhorov, A; Hecht, I; Sela, U; Vlodavsky, I; Nagler, A

    2006-08-01

    Halofuginone, a low molecular weight plant alkaloid, inhibits collagen alpha1 (I) gene expression in several animal models and in patients with fibrotic disease, including scleroderma and graft-versus-host disease. In addition, halofuginone has been shown to inhibit angiogenesis and tumor progression. It was demonstrated recently that halofuginone inhibits transforming growth factor-beta (TGF-beta), an important immunomodulator. The present study was undertaken to explore the effects of halofuginone on activated T cells. Peripheral blood T cells were activated by anti-CD3 monoclonal antibodies in the absence and presence of halofuginone and assessed for nuclear factor (NF)-kappaB activity, production of tumor necrosis factor alpha (TNF-alpha) and interferon-gamma (IFN-gamma), T cell apoptosis, chemotaxis, and phosphorylation of p38 mitogen-activated protein kinase (MAPK). A delayed-type hypersensitivity (DTH) model was applied to investigate the effect of halofuginone on T cells in vivo. Preincubation of activated peripheral blood T cells with 10-40 ng/ml halofuginone resulted in a significant dose-dependent decrease in NF-kappaB activity (80% inhibition following incubation with 40 ng halofuginone, P = 0.002). In addition, 40 ng/ml halofuginone inhibited secretion of TNF-alpha, IFN-gamma, interleukin (IL)-4, IL-13, and TGF-beta (P < 0.005). Similarly, halofuginone inhibited the phosphorylation of p38 MAPK and apoptosis in activated T cells (P = 0.0001 and 0.005, respectively). In contrast, T cell chemotaxis was not affected. Halofuginone inhibited DTH response in mice, indicating suppression of T cell-mediated inflammation in vivo. Halofuginone inhibits activated peripheral blood T cell functions and proinflammatory cytokine production through inhibition of NF-kappaB activation and p38 MAPK phosphorylation. It also inhibited DTH response in vivo, making it an attractive immunomodulator and anti-inflammatory agent. PMID:16769768

  20. A novel p38 mitogen activated protein kinase (MAPK) specific inhibitor suppresses respiratory syncytial virus and influenza A virus replication by inhibiting virus-induced p38 MAPK activation.

    PubMed

    Choi, Myung-Soo; Heo, Jinyuk; Yi, Chae-Min; Ban, Junsu; Lee, Noh-Jin; Lee, Na-Rae; Kim, Sang Won; Kim, Nam-Jung; Inn, Kyung-Soo

    2016-08-26

    Respiratory syncytial virus (RSV) and influenza A virus are leading causes of acute lower respiratory infectious disease. Respiratory diseases caused by RSV and influenza A virus result in serious economic burden and life-threatening disease for immunocompromised people. With the revelation that p38 mitogen-activated protein kinase (MAPK) activity in host cells is crucial for infection and replication of RSV and influenza A virus, inhibition of p38 MAPK activity has been suggested as a potential antiviral therapeutic strategy. However, the low selectivity and high toxicity of the p38 MAPK inhibitors necessitate the development of better inhibitors. Herein, we report the synthesis of a novel p38 MAPK inhibitor, NJK14047, with high kinase selectivity. In this work, it was demonstrated that NJK14047 inhibits RSV- and influenza A-mediated p38 MAPK activation in epithelial cells. Subsequently, NJK14047 treatment resulted in decreased viral replication and viral mRNA synthesis. In addition, secretion of interleukin-6 from infected cells was greatly diminished by NJK14047, suggesting that it can ameliorate immunopathological responses to RSV and influenza A. Collectively, the results suggest that NJK14047 has therapeutic potential to treat respiratory viral infection through the suppression of p38 MAPK activation, which is suggested to be an essential step for respiratory virus infection. PMID:27346133

  1. Neospora caninum Activates p38 MAPK as an Evasion Mechanism against Innate Immunity

    PubMed Central

    Mota, Caroline M.; Oliveira, Ana C. M.; Davoli-Ferreira, Marcela; Silva, Murilo V.; Santiago, Fernanda M.; Nadipuram, Santhosh M.; Vashisht, Ajay A.; Wohlschlegel, James A.; Bradley, Peter J.; Silva, João S.; Mineo, José R.; Mineo, Tiago W. P.

    2016-01-01

    Due to the high prevalence and economic impact of neosporosis, the development of safe and effective vaccines and therapies against this parasite has been a priority in the field and is crucial to limit horizontal and vertical transmission in natural hosts. Limited data is available regarding factors that regulate the immune response against this parasite and such knowledge is essential in order to understand Neospora caninum induced pathogenesis. Mitogen-activated protein kinases (MAPKs) govern diverse cellular processes, including growth, differentiation, apoptosis, and immune-mediated responses. In that sense, our goal was to understand the role of MAPKs during the infection by N. caninum. We found that p38 phosphorylation was quickly triggered in macrophages stimulated by live tachyzoites and antigen extracts, while its chemical inhibition resulted in upregulation of IL-12p40 production and augmented B7/MHC expression. In vivo blockade of p38 resulted in an amplified production of cytokines, which preceded a reduction in latent parasite burden and enhanced survival against the infection. Additionally, the experiments indicate that the p38 activation is induced by a mechanism that depends on GPCR, PI3K and AKT signaling pathways, and that the phenomena here observed is distinct that those induced by Toxoplasma gondii’s GRA24 protein. Altogether, these results showed that N. caninum manipulates p38 phosphorylation in its favor, in order to downregulate the host’s innate immune responses. Additionally, those results infer that active interference in this signaling pathway may be useful for the development of a new therapeutic strategy against neosporosis. PMID:27679624

  2. Neospora caninum Activates p38 MAPK as an Evasion Mechanism against Innate Immunity

    PubMed Central

    Mota, Caroline M.; Oliveira, Ana C. M.; Davoli-Ferreira, Marcela; Silva, Murilo V.; Santiago, Fernanda M.; Nadipuram, Santhosh M.; Vashisht, Ajay A.; Wohlschlegel, James A.; Bradley, Peter J.; Silva, João S.; Mineo, José R.; Mineo, Tiago W. P.

    2016-01-01

    Due to the high prevalence and economic impact of neosporosis, the development of safe and effective vaccines and therapies against this parasite has been a priority in the field and is crucial to limit horizontal and vertical transmission in natural hosts. Limited data is available regarding factors that regulate the immune response against this parasite and such knowledge is essential in order to understand Neospora caninum induced pathogenesis. Mitogen-activated protein kinases (MAPKs) govern diverse cellular processes, including growth, differentiation, apoptosis, and immune-mediated responses. In that sense, our goal was to understand the role of MAPKs during the infection by N. caninum. We found that p38 phosphorylation was quickly triggered in macrophages stimulated by live tachyzoites and antigen extracts, while its chemical inhibition resulted in upregulation of IL-12p40 production and augmented B7/MHC expression. In vivo blockade of p38 resulted in an amplified production of cytokines, which preceded a reduction in latent parasite burden and enhanced survival against the infection. Additionally, the experiments indicate that the p38 activation is induced by a mechanism that depends on GPCR, PI3K and AKT signaling pathways, and that the phenomena here observed is distinct that those induced by Toxoplasma gondii’s GRA24 protein. Altogether, these results showed that N. caninum manipulates p38 phosphorylation in its favor, in order to downregulate the host’s innate immune responses. Additionally, those results infer that active interference in this signaling pathway may be useful for the development of a new therapeutic strategy against neosporosis.

  3. Neospora caninum Activates p38 MAPK as an Evasion Mechanism against Innate Immunity.

    PubMed

    Mota, Caroline M; Oliveira, Ana C M; Davoli-Ferreira, Marcela; Silva, Murilo V; Santiago, Fernanda M; Nadipuram, Santhosh M; Vashisht, Ajay A; Wohlschlegel, James A; Bradley, Peter J; Silva, João S; Mineo, José R; Mineo, Tiago W P

    2016-01-01

    Due to the high prevalence and economic impact of neosporosis, the development of safe and effective vaccines and therapies against this parasite has been a priority in the field and is crucial to limit horizontal and vertical transmission in natural hosts. Limited data is available regarding factors that regulate the immune response against this parasite and such knowledge is essential in order to understand Neospora caninum induced pathogenesis. Mitogen-activated protein kinases (MAPKs) govern diverse cellular processes, including growth, differentiation, apoptosis, and immune-mediated responses. In that sense, our goal was to understand the role of MAPKs during the infection by N. caninum. We found that p38 phosphorylation was quickly triggered in macrophages stimulated by live tachyzoites and antigen extracts, while its chemical inhibition resulted in upregulation of IL-12p40 production and augmented B7/MHC expression. In vivo blockade of p38 resulted in an amplified production of cytokines, which preceded a reduction in latent parasite burden and enhanced survival against the infection. Additionally, the experiments indicate that the p38 activation is induced by a mechanism that depends on GPCR, PI3K and AKT signaling pathways, and that the phenomena here observed is distinct that those induced by Toxoplasma gondii's GRA24 protein. Altogether, these results showed that N. caninum manipulates p38 phosphorylation in its favor, in order to downregulate the host's innate immune responses. Additionally, those results infer that active interference in this signaling pathway may be useful for the development of a new therapeutic strategy against neosporosis. PMID:27679624

  4. 2-Methoxyestradiol induced Bax phosphorylation and apoptosis in human retinoblastoma cells via p38 MAPK activation.

    PubMed

    Min, Hongbo; Ghatnekar, Gautam S; Ghatnekar, Angela V; You, Xiaohong; Bu, Min; Guo, Xinyi; Bu, Shizhong; Shen, Bo; Huang, Qin

    2012-07-01

    Retinoblastoma (Rb) is a common childhood intraocular cancer that affects approximately 300 children each year in the United States alone. 2-Methoxyestradiol (2ME), an endogenous metabolite of 17-β-estradiol that dose not bind to nuclear estrogen receptor, exhibits potent apoptotic activity against rapidly growing tumor cells. Here, we report that 2ME induction of apoptosis was demonstrated by early fragmented DNA after 48 h of incubation with 10 µM 2ME in Rb cell lines. Subsequently, a decrease of proliferation was observed in a time- and dose-dependent manner. Further analysis of the mechanism indicates that p38 kinase plays a critical role in 2ME-induced apoptosis in Y79 cells, even though ERK was also activated by 2ME under the same conditions. Activation of p38 kinase also mediates 2ME induced Bax phosphorylated at Thr(167) after a 6 h treatment of 2ME, which in turn prevents formation of the Bcl-2-Bax heterodimer. Both p38 specific inhibitor, SB 203580, or p38 knockdown by specific siRNA, blocked 2ME induction of Bax phosphorylation. Furthermore, only transiently transfected mutant BaxT167A, but not Bax S163A, inhibited 2ME-induced apoptosis. In summary, our data suggest that 2ME induces apoptosis in human Rb cells by causing phosphorylation of p38 Mitogen-activated protein kinase (MAPK), which appears to be correlated with phosphorlation of Bax. This understanding of 2ME's ability may help develop it as a promising therapeutic candidate by inducing apoptosis in a Rb. PMID:21769948

  5. Endothelium-Derived 5-Methoxytryptophan Protects Endothelial Barrier Function by Blocking p38 MAPK Activation

    PubMed Central

    Chu, Ling-Yun; Wang, Yi-Fu; Cheng, Huei-Hsuan; Kuo, Cheng-Chin; Wu, Kenneth K.

    2016-01-01

    The endothelial junction is tightly controlled to restrict the passage of blood cells and solutes. Disruption of endothelial barrier function by bacterial endotoxins, cytokines or growth factors results in inflammation and vascular damage leading to vascular diseases. We have identified 5-methoxytryptophan (5-MTP) as an anti-inflammatory factor by metabolomic analysis of conditioned medium of human fibroblasts. Here we postulated that endothelial cells release 5-MTP to protect the barrier function. Conditioned medium of human umbilical vein endothelial cells (HUVECs) prevented endothelial hyperpermeability and VE-cadherin downregulation induced by VEGF, LPS and cytokines. We analyzed the metabolomic profile of HUVEC conditioned medium and detected 5-MTP but not melatonin, serotonin or their catabolites, which was confirmed by enzyme-linked immunosorbent assay. Addition of synthetic pure 5-MTP preserved VE-cadherin and maintained barrier function despite challenge with pro-inflammatory mediators. Tryptophan hydroxylase-1, an enzyme required for 5-MTP biosynthesis, was downregulated in HUVECs by pro-inflammatory mediators and it was accompanied by reduction of 5-MTP. 5-MTP protected VE-cadherin and prevented endothelial hyperpermeability by blocking p38 MAPK activation. A chemical inhibitor of p38 MAPK, SB202190, exhibited a similar protective effect as 5-MTP. To determine whether 5-MTP prevents vascular hyperpermeability in vivo, we evaluated the effect of 5-MTP administration on LPS-induced murine microvascular permeability with Evans blue. 5-MTP significantly prevented Evans blue dye leakage. Our findings indicate that 5-MTP is a new class of endothelium-derived molecules which protects endothelial barrier function by blocking p38 MAPK. PMID:27002329

  6. Endothelium-Derived 5-Methoxytryptophan Protects Endothelial Barrier Function by Blocking p38 MAPK Activation.

    PubMed

    Chu, Ling-Yun; Wang, Yi-Fu; Cheng, Huei-Hsuan; Kuo, Cheng-Chin; Wu, Kenneth K

    2016-01-01

    The endothelial junction is tightly controlled to restrict the passage of blood cells and solutes. Disruption of endothelial barrier function by bacterial endotoxins, cytokines or growth factors results in inflammation and vascular damage leading to vascular diseases. We have identified 5-methoxytryptophan (5-MTP) as an anti-inflammatory factor by metabolomic analysis of conditioned medium of human fibroblasts. Here we postulated that endothelial cells release 5-MTP to protect the barrier function. Conditioned medium of human umbilical vein endothelial cells (HUVECs) prevented endothelial hyperpermeability and VE-cadherin downregulation induced by VEGF, LPS and cytokines. We analyzed the metabolomic profile of HUVEC conditioned medium and detected 5-MTP but not melatonin, serotonin or their catabolites, which was confirmed by enzyme-linked immunosorbent assay. Addition of synthetic pure 5-MTP preserved VE-cadherin and maintained barrier function despite challenge with pro-inflammatory mediators. Tryptophan hydroxylase-1, an enzyme required for 5-MTP biosynthesis, was downregulated in HUVECs by pro-inflammatory mediators and it was accompanied by reduction of 5-MTP. 5-MTP protected VE-cadherin and prevented endothelial hyperpermeability by blocking p38 MAPK activation. A chemical inhibitor of p38 MAPK, SB202190, exhibited a similar protective effect as 5-MTP. To determine whether 5-MTP prevents vascular hyperpermeability in vivo, we evaluated the effect of 5-MTP administration on LPS-induced murine microvascular permeability with Evans blue. 5-MTP significantly prevented Evans blue dye leakage. Our findings indicate that 5-MTP is a new class of endothelium-derived molecules which protects endothelial barrier function by blocking p38 MAPK.

  7. Hydrogen peroxide signaling mediator in the activation of p38 MAPK in vascular endothelial cells.

    PubMed

    Bretón-Romero, Rosa; Lamas, Santiago

    2013-01-01

    Substantial evidence suggests that a transient increase of hydrogen peroxide (H2O2) behaves as an intracellular messenger able to trigger the activation of different signaling pathways. These include phosphatases, protein kinases, and transcription factors among others; however, most of the studies have been performed using supraphysiological levels of H2O2. Reactive oxygen species (ROS) generation occurs under physiological conditions and different extracellular stimuli including cytokines, growth factors, and shear stress are able to produce both low levels of superoxide anion and H2O2. Here, we explore the redox-dependent activation of key signaling pathways induced by shear stress. We demonstrate that laminar shear stress (LSS) rapidly promotes a transient generation of H2O2 that is necessary for the activation of the stress-activated protein kinase p38 MAPK. We describe p38 MAPK as an early redox sensor in LSS. Our studies show that it is essential for the activation of endothelial nitric oxide synthase, the subsequent nitric oxide generation, and the protection of endothelial function.

  8. Nobiletin suppresses MMP-9 expression through modulation of p38 MAPK activity in human dermal fibrobalsts.

    PubMed

    Kim, Jin-Ju; Korm, Sovannarith; Kim, Won-Seok; Kim, Ok-Seon; Lee, Ji-Seon; Min, Hyung-Geun; Chin, Young-Won; Cha, Hyuk-Jin

    2014-01-01

    We aimed to identify a novel flavonoid from the in-house natural products to suppress matrix metalloproteases (MMPs), which is responsible for degradation of collagen and other extracellular matrix proteins. Total eight natural products were screened for identification of a novel MMP-9 suppressor using MMP-9 reporter system, where the prompt initial screening with multiple samples is readily examined. Among the extracts used in the present study, one extract (Citrus unshiu) was found active in this assay system. Furthermore, three representative flavonoids in this active extract of Citrus unshiu peel were tested in MMP-9 reporter system. Nobiletin (NB) of the tested flavonoids suppressed MMP-9 expression without cytotoxicity, which was validated by both real-time polymerase chain reaction (PCR) and zymography analyses. Sustained p38 mitogen activated protein kinase (MAPK) activity, closely associated with induction of MMP-9 under stress condition, was markedly reduced by NB treatment, which implies that modulation of p38MAPK by nobiletin is responsible for reduction of MMP9 expression. Hence, nobiletin, identified from MMP-9 reporter system based screening, may be further applied for the purpose of delaying collagen degradation in skin fibroblasts.

  9. The role of p38 MAPK activation in auranofin-induced apoptosis of human promyelocytic leukaemia HL-60 cells

    PubMed Central

    Park, Seon-Joo; Kim, In-Sook

    2005-01-01

    In a previous study, we reported an antileukaemic activity of auranofin (AF), demonstrating its dual effects: on the induction of apoptotic cell death and its synergistic action with retinoic acid on cell differentiation. In this study, we investigated the downstream signalling events of AF-induced apoptosis to determine the molecular mechanisms of AF activity. Treatment of HL-60 cells with AF induced apoptosis in a concentration- and time-dependent manner. Western blot analysis showed that AF-induced apoptosis was accompanied by the activation of caspase-8, caspase-9, and caspase-3, and the release of cytochrome c from the mitochondria. The phosphorylation and kinase activities of p38 mitogen-activated protein kinase (p38 MAPK) increased gradually until 12 h after AF (2 μM) treatment, and p38 MAPK was also activated concentration-dependently. Pretreatment with SB203580, a specific inhibitor of p38 MAPK, significantly blocked DNA fragmentation and the cleavage of procaspase-8, procaspase-3, and poly-ADP-ribose polymerase (PARP), whereas SB203580 alone had no effect. Reactive oxygen species (ROS) were also detected within 1 h after AF treatment, and the antioxidant N-acetyl-L-cysteine (NAC) effectively protected the cells from apoptosis by inhibiting the phosphorylation of p38 MAPK and the activation of caspases. These results suggest that ROS generation and the subsequent activation of p38 MAPK are essential for the proapoptotic effects of AF in human promyelocytic leukaemia HL-60 cells. PMID:16086031

  10. CyHV-2 ORF104 activates the p38 MAPK pathway.

    PubMed

    Du, Mi; Chen, Mingliang; Shen, Haifeng; Wang, Wei; Li, Zengpeng; Wang, Weiyi; Huang, Jianhui; Chen, Jianming

    2015-10-01

    Cyprinid herpesvirus 2 (CyHV-2) is the pathogen responsible for herpesviral hematopoietic necrosis disease, which causes huge losses on aquaculture. So far the studies of CyHV-2 mainly focus on the identification and detection of this virus, but little is known about the role of specific CyHV-2 genes in the infection process. Based on the genomic information, CyHV-2 ORF104 encodes a kinase-like protein, which is highly conserved among the three CyHVs. Our study was initiated to investigate the role of kinase-like protein ORF104 during virus infection. Subcellular localization study showed that ORF104 was mainly expressed in the nucleus in both human HEK293T and fish EPC cells. However, deletion of the putative nuclear localization signal of ORF104 (ORF104M) resulted in the cytoplasmic distribution in HEK293T. We then examined whether MAPKs were involved in the ORF104-mediated signaling pathway by overexpressing ORF104 and ORF104M in HEK293T. Overexpression of ORF104 and ORF104M resulted in the up-regulation of p38 phosphorylation, but not JNK or ERK, indicating that ORF104 specifically activates p38 signaling pathway. In vivo study showed that CyHV-2 infection enhanced p38 phosphorylation in gibel carp (Carassius auratus gibelio). Interestingly, p38 inhibitor SB203580 strongly reduced fish death caused by CyHV-2 infection. Therefore, our study for the first time reveals the function of ORF104 during CyHV-2 infection, indicating that ORF104 is a potential vaccine candidate for CyHV-2.

  11. p38 MAPK Signaling in Osteoblast Differentiation

    PubMed Central

    Rodríguez-Carballo, Eddie; Gámez, Beatriz; Ventura, Francesc

    2016-01-01

    The skeleton is a highly dynamic tissue whose structure relies on the balance between bone deposition and resorption. This equilibrium, which depends on osteoblast and osteoclast functions, is controlled by multiple factors that can be modulated post-translationally. Some of the modulators are Mitogen-activated kinases (MAPKs), whose role has been studied in vivo and in vitro. p38-MAPK modifies the transactivation ability of some key transcription factors in chondrocytes, osteoblasts and osteoclasts, which affects their differentiation and function. Several commercially available inhibitors have helped to determine p38 action on these processes. Although it is frequently mentioned in the literature, this chemical approach is not always as accurate as it should be. Conditional knockouts are a useful genetic tool that could unravel the role of p38 in shaping the skeleton. In this review, we will summarize the state of the art on p38 activity during osteoblast differentiation and function, and emphasize the triggers of this MAPK. PMID:27200351

  12. Aluminum Nanoparticles Induce ERK and p38MAPK Activation in Rat Brain

    PubMed Central

    Seo, Gyun-Baek; Jo; Lee, Mimi; Shim, Ilseob; Lee, Byung-Woo; Yoon, Byung-Il; Kim, Pilje; Choi, Kyunghee

    2013-01-01

    Aluminum nanoparticles (Al-NPs) are one of the most widely used nanomaterial in cosmetics and medical materials. For this reason, Al-NP exposure is very likely to occur via inhalation in the environment and the workplace. Nevertheless, little is known about the mechanism of Al-NP neurotoxicity via inhalation exposure. In this study, we investigated the effect AL-NPs on the brain. Rats were exposed to Al-NPs by nasal instillation at 1 mg/kg body weight (low exposure group), 20 mg/kg body weight (moderate exposure group), and 40 mg/kg body weight (high exposure group), for a total of 3 times, with a 24-hr interval after each exposure. Inductively coupled plasma mass spectrometry (ICP-MS) analysis indicated that the presence of aluminum was increased in a dose-dependent manner in the olfactory bulb (OFB) and the brain. In microarray analysis, the regulation of mitogen-activated protein kinases (MAPK) activity (GO: 0043405), including Ptprc, P2rx7, Map2k4, Trib3, Trib1, and Fgd4 was significantly over-expressed in the treated mice than in the controls (p = 0.0027). Moreover, Al-NPs induced the activation of ERK1 and p38 MAPK protein expression in the brain, but did not alter the protein expression of JNK, when compared to the control. These data demonstrate that the nasal exposure of Al-NPs can permeate the brain via the olfactory bulb and modulate the gene and protein expression of MAPK and its activity. PMID:24386518

  13. TACE release of TNF-α mediates mechanotransduction-induced activation of p38 MAPK and myogenesis

    PubMed Central

    Zhan, Mei; Jin, Bingwen; Chen, Shuen-Ei; Reecy, James M.; Li, Yi-Ping

    2011-01-01

    Summary Skeletal muscle responds to mechanical stimulation by activating p38 MAPK, a key signal for myogenesis. However, the mechanotransduction mechanism that activates p38 is unknown. Here we show that mechanical stimulation of myoblasts activates p38 and myogenesis through stimulating TNF-α release by TNF-α converting enzyme (TACE). In C2C12 or mouse primary myoblasts cultured in growth medium, static stretch activated p38 along with ERK1/2, JNK and AKT. Disrupting TNF-α signaling by TNF-α-neutralizing antibody or knocking out TNF-α receptors blocked stretch activation of p38, but not ERK1/2, JNK or AKT. Stretch also activated differentiation markers MEF2C, myogenin, p21 and myosin heavy chain in a TNF-α- and p38-dependent manner. Stretch stimulated the cleavage activity of TACE. Conversely, TACE inhibitor TAPI or TACE siRNA abolished stretch activation of p38. In addition, conditioned medium from stretched myoblast cultures activated p38 in unstretched myoblasts, which required TACE activity in the donor myoblasts, and TNF-α receptors in the recipient myoblasts. These results indicate that posttranscriptional activation of TACE mediates the mechanotransduction that activates p38-dependent myogenesis via the release of TNF-α. PMID:17264149

  14. Activation of HuR downstream of p38 MAPK promotes cardiomyocyte hypertrophy.

    PubMed

    Slone, Samuel; Anthony, Sarah R; Wu, Xiaoqing; Benoit, Joshua B; Aube, Jeffrey; Xu, Liang; Tranter, Michael

    2016-11-01

    The RNA binding protein Human antigen R (HuR) interacts with specific AU-rich domains in target mRNAs and is highly expressed in many cell types, including cardiomyocytes. However, the role of HuR in cardiac physiology is largely unknown. Our results show that HuR undergoes cytoplasmic translocation, indicative of its activation, in hypertrophic cardiac myocytes. Specifically, HuR cytoplasmic translocation is significantly increased in NRVMs (neonatal rat ventricular myocytes) following treatment with phenylephrine or angiotensin II, agonists of two independent Gαq-coupled GPCRs known to induce hypertrophy. This Gq-mediated HuR activation is dependent on p38 MAP kinase, but not canonical Gq-PKC signaling. Furthermore, we show that HuR activation is necessary for Gq-mediated hypertrophic growth of NRVMs as siRNA-mediated knockdown of HuR inhibits hypertrophy as measured by cell size and expression of ANF (atrial natriuretic factor). Additionally, HuR overexpression is sufficient to induce hypertrophic cell growth. To decipher the downstream mechanisms by which HuR translocation promotes cardiomyocyte hypertrophy, we assessed the role of HuR in the transcriptional activity of NFAT (nuclear factor of activated T cells), the activation of which is a hallmark of cardiac hypertrophy. Using an NFAT-luciferase reporter assay, we show an acute inhibition of NFAT transcriptional activity following pharmacological inhibition of HuR. In conclusion, our results identify HuR as a novel mediator of cardiac hypertrophy downstream of the Gq-p38 MAPK pathway, and suggest modulation of NFAT activity as a potential mechanism.

  15. Kappa Opioid Receptor Activation of p38 MAPK Is GRK3- and Arrestin-dependent in Neurons and Astrocytes*

    PubMed Central

    Bruchas, Michael R.; Macey, Tara A.; Lowe, Janet D.; Chavkin, Charles

    2007-01-01

    AtT-20 cells expressing the wild-type kappa opioid receptor (KOR) increased phospho-p38 MAPK following treatment with the kappa agonist U50,488. The increase was blocked by the kappa antagonist norbinaltorphimine and not evident in untransfected cells. In contrast, U50,488 treatment of AtT-20 cells expressing KOR having alanine substituted for serine-369 (KSA) did not increase phospho-p38. Phosphorylation of serine 369 in the KOR carboxyl terminus by G-protein receptor kinase 3 (GRK3) was previously shown to be required for receptor desensitization, and the results suggest that p38 MAPK activation by KOR may require arrestin recruitment. This hypothesis was tested by transfecting arrestin3-(R170E), a dominant positive form of arrestin that does not require receptor phosphorylation for activation. AtT-20 cells expressing both KSA and arrestin3-(R170E) responded to U50,488 treatment with an increase in phospho-p38 consistent with the hypothesis. Primary cultured astrocytes (glial fibrillary acidic protein-positive) and neurons (γ-aminobutyric acid-positive) isolated from mouse striata also responded to U50,488 by increasing phospho-p38 immunolabeling. p38 activation was not evident in either striatal astrocytes or neurons isolated from KOR knock-out mice or GRK3 knock-out mice. Astrocytes pretreated with small interfering RNA for arrestin3 were also unable to activate p38 in response to U50,488 treatment. Furthermore, in striatal neurons, the kappa-mediated phospho-p38 labeling was colocalized with arrestin3. These findings suggest that KOR may activate p38 MAPK in brain by a GRK3 and arrestin-dependent mechanism. PMID:16648139

  16. Trientine, a copper-chelating agent, induced apoptosis in murine fibrosarcoma cells by activation of the p38 MAPK pathway.

    PubMed

    KADOWAKI, Shingo; ENDOH, Daiji; OKUI, Toyo; HAYASHI, Masanobu

    2009-11-01

    We have reported that treatment with trientine, Cu-chelating agent, inhibits tumor growth in a murine transplantation model using fibrosarcoma and induces apoptosis in tumor cells in vivo and in vitro. When fibrosarcoma cells were treated with 10 mM trientine, the activities of p38 MAPK in treated cells were approximately 3-4 times higher than those in untreated cells. Proportions of cells in which apoptosis was induced by trientine increased in an incubation time-dependent manner from days 2 to 6. The proportions of apoptotic cells in the cells treated with trientine and SB203580, an inhibitor of p38 MAPK, were approximately 50% in those of cells treated with trientine alone. The present results showed that the p38 MAPK pathway may play an important role in induction of apoptosis in fibrosarcoma cells by trientine.

  17. Oridonin upregulates PTEN through activating p38 MAPK and inhibits proliferation in human colon cancer cells.

    PubMed

    Wu, Qiu-Xiang; Yuan, Shuang-Xue; Ren, Chun-Mei; Yu, Yu; Sun, Wen-Juan; He, Bai-Cheng; Wu, Ke

    2016-06-01

    Oridonin (ORI) has been reported as an antiproliferation and apoptosis-inducing natural product in various cancer cells. However, the exact molecular mechanism underlying these effects remains unclear. In the present study, we demonstrated the antiproliferation effect of ORI in HCT116 cells, and analyzed the possible molecular mechanism which mediates this effect. We found that ORI inhibits proliferation, induces cell cycle arrest and apoptosis in HCT116 cells, thus also tumor growth. Mechanically, we found that ORI has no substantial effect on mRNA expression of phosphatase and tensin homologue (PTEN), but increases the total protein level of PTEN and markedly reduces the phosphorylation of PTEN; Exogenous expression of PTEN potentiates the anticancer effect of ORI, while knockdown of PTEN attenuates it. ORI also increases the phosphorylation of p38 MAPK, and p38 MAPK-specific inhibitor reduces the antiproliferation effect ORI in HCT116 cells. Moreover, inhibition of p38 MAPK increases the phosphorylation of PTEN, and reverses ORI-induced decrease of PTEN phosphorylation. Our findings suggested that ORI may be a potential anticancer drug for colon cancer, this effect may be mediated by enhancing the function of PTEN through reducing its phosphorylation, which may be resulted from the ORI-induced activation of p38 MAPK.

  18. HIV-1 Nef-induced FasL induction and bystander killing requires p38 MAPK activation

    PubMed Central

    Muthumani, Karuppiah; Choo, Andrew Y.; Hwang, Daniel S.; Premkumar, Arumugam; Dayes, Nathanael S.; Harris, Crafford; Green, Douglas R.; Wadsworth, Scott A.; Siekierka, John J.; Weiner, David B.

    2005-01-01

    The human immunodeficiency virus (HIV) has been reported to target noninfected CD4 and CD8 cells for destruction. This effect is manifested in part through up-regulation of the death receptor Fas ligand (FasL) by HIV-1 negative factor (Nef), leading to bystander damage. However, the signal transduction and transcriptional regulation of this process remains elusive. Here, we provide evidence that p38 mitogen-activated protein kinase (MAPK) is required for this process. Loss-of-function experiments through dominant-negative p38 isoform, p38 siRNA, and chemical inhibitors of p38 activation suggest that p38 is necessary for Nef-induced activator protein-1 (AP-1) activation, as inhibition leads to an attenuation of AP-1-dependent transcription. Furthermore, mutagenesis of the FasL promoter reveals that its AP-1 enhancer element is required for Nef-mediated transcriptional activation. Therefore, a linear pathway for Nef-induced FasL expression that encompasses p38 and AP-1 has been elucidated. Furthermore, chemical inhibition of the p38 pathway attenuates HIV-1-mediated bystander killing of CD8 cells in vitro. (Blood. 2005;106:2059-2068) PMID:15928037

  19. Immunosuppressant MPA Modulates Tight Junction through Epigenetic Activation of MLCK/MLC-2 Pathway via p38MAPK

    PubMed Central

    Khan, Niamat; Pantakani, D. V. Krishna; Binder, Lutz; Qasim, Muhammad; Asif, Abdul R.

    2015-01-01

    Background: Mycophenolic acid (MPA) is an important immunosuppressive drug (ISD) prescribed to prevent graft rejection in the organ transplanted patients, however, its use is also associated with adverse side effects like sporadic gastrointestinal (GI) disturbances. Recently, we reported the MPA induced tight junctions (TJs) deregulation which involves MLCK/MLC-2 pathway. Here, we investigated the global histone acetylation as well as gene-specific chromatin signature of several genes associated with TJs regulation in Caco-2 cells after MPA treatment. Results: The epigenetic analysis shows that MPA treatment increases the global histone acetylation levels as well as the enrichment for transcriptional active histone modification mark (H3K4me3) at promoter regions of p38MAPK, ATF-2, MLCK, and MLC-2. In contrast, the promoter region of occludin was enriched for transcriptional repressive histone modification mark (H3K27me3) after MPA treatment. In line with the chromatin status, MPA treatment increased the expression of p38MAPK, ATF-2, MLCK, and MLC-2 both at transcriptional and translational level, while occludin expression was negatively influenced. Interestingly, the MPA induced gene expression changes and functional properties of Caco-2 cells could be blocked by the inhibition of p38MAPK using a chemical inhibitor (SB203580). Conclusions: Collectively, our results highlight that MPA disrupts the structure of TJs via p38MAPK-dependent activation of MLCK/MLC-2 pathway that results in decreased integrity of Caco-2 monolayer. These results led us to suggest that p38MAPK-mediated lose integrity of epithelial monolayer could be the possible cause of GI disturbance (barrier dysfunction) in the intestine, leading to leaky style diarrhea observed in the organ-transplanted patients treated with MPA. PMID:26733876

  20. Maternal inflammation activated ROS-p38 MAPK predisposes offspring to heart damages caused by isoproterenol via augmenting ROS generation

    PubMed Central

    Zhang, Qi; Deng, Yafei; Lai, Wenjing; Guan, Xiao; Sun, Xiongshan; Han, Qi; Wang, Fangjie; Pan, Xiaodong; Ji, Yan; Luo, Hongqin; Huang, Pei; Tang, Yuan; Gu, Liangqi; Dan, Guorong; Yu, Jianhua; Namaka, Michael; Zhang, Jianxiang; Deng, Youcai; Li, Xiaohui

    2016-01-01

    Maternal inflammation contributes to the increased incidence of adult cardiovascular disease. The current study investigated the susceptibility of cardiac damage responding to isoproterenol (ISO) in adult offspring that underwent maternal inflammation (modeled by pregnant Sprague-Dawley rats with lipopolysaccharides (LPS) challenge). We found that 2 weeks of ISO treatment in adult offspring of LPS-treated mothers led to augmented heart damage, characterized by left-ventricular systolic dysfunction, cardiac hypertrophy and myocardial fibrosis. Mechanistically, prenatal exposure to LPS led to up-regulated expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, antioxidant enzymes, and p38 MAPK activity in left ventricular of adult offspring at resting state. ISO treatment exaggerated ROS generation, p38 MAPK activation but down-regulated reactive oxygen species (ROS) elimination capacity in the left ventricular of offspring from LPS-treated mothers, while antioxidant N-acetyl-L-cysteine (NAC) reversed these changes together with improved cardiac functions. The p38 inhibitor SB202190 alleviated the heart damage only via inhibiting the expression of NADPH oxidases. Collectively, our data demonstrated that prenatal inflammation programs pre-existed ROS activation in the heart tissue, which switches on the early process of oxidative damages on heart rapidly through a ROS-p38 MAPK-NADPH oxidase-ROS positive feedback loop in response to a myocardial hypertrophic challenge in adulthood. PMID:27443826

  1. p38 MAPK Signaling in Pemphigus: Implications for Skin Autoimmunity

    PubMed Central

    Mavropoulos, Athanasios; Orfanidou, Timoklia; Liaskos, Christos; Smyk, Daniel S.; Spyrou, Vassiliki; Sakkas, Lazaros I.; Rigopoulou, Eirini I.; Bogdanos, Dimitrios P.

    2013-01-01

    p38 mitogen activated protein kinase (p38 MAPK) signaling plays a major role in the modulation of immune-mediated inflammatory responses and therefore has been linked with several autoimmune diseases. The extent of the involvement of p38 MAPK in the pathogenesis of autoimmune blistering diseases has started to emerge, but whether it pays a critical role is a matter of debate. The activity of p38 MAPK has been studied in great detail during the loss of keratinocyte cell-cell adhesions and the development of pemphigus vulgaris (PV) and pemphigus foliaceus (PF). These diseases are characterised by autoantibodies targeting desmogleins (Dsg). Whether autoantibody-antigen interactions can trigger signaling pathways (such as p38 MAPK) that are tightly linked to the secretion of inflammatory mediators which may perpetuate inflammation and tissue damage in pemphigus remains unclear. Yet, the ability of p38 MAPK inhibitors to block activation of the proapoptotic proteinase caspase-3 suggests that the induction of apoptosis may be a consequence of p38 MAPK activation during acantholysis in PV. This review discusses the current evidence for the role of p38 MAPK in the pathogenesis of pemphigus. We will also present data relating to the targeting of these cascades as a means of therapeutic intervention. PMID:23936634

  2. Hypoxia differentially regulates the mitogen- and stress-activated protein kinases. Role of Ca2+/CaM in the activation of MAPK and p38 gamma.

    PubMed

    Conrad, P W; Millhorn, D E; Beitner-Johnson, D

    2000-01-01

    Hypoxic/ischemic trauma is a primary factor in the pathology of various vascular, pulmonary, and cerebral disease states. Yet, the signaling mechanisms by which cells respond and adapt to changes in oxygen levels are not clearly established. The effects of hypoxia on the stress- and mitogen-activated protein kinase (SAPK and MAPK) signaling pathways were studied in PC12 cells. Exposure to moderate hypoxia (5% O2) was found to progressively stimulate phosphorylation and activation of p38 gamma in particular, and also p38 alpha, two isoforms of the p38 family of stress-activated protein kinases. In contrast, hypoxia had no effect on enzyme activity of p38 beta, p38 beta 2, p38 delta, or on JNK, another stress-activated protein kinase. Prolonged hypoxia also induced phosphorylation and activation of p42/p44 MAPK, although this activation was modest when compared to NGF and UV-induced activation. We further showed that activation of p38 gamma and MAPK during hypoxia requires calcium, as treatment with Ca(2+)-free media or the calmodulin antagonist, W13, blocked the activation of p38 gamma and MAPK, respectively. These studies demonstrate that an extremely typical physiological stress (hypoxia) causes selective activation of specific elements of the SAPKs and MAPKs, and identifies Ca+2/CaM as a critical upstream activator. PMID:10849670

  3. Thrombin Enhances NGF-Mediated Neurite Extension via Increased and Sustained Activation of p44/42 MAPK and p38 MAPK

    PubMed Central

    Mufti, Rania E.; Sarker, Krishna; Jin, Yan; Fu, Songbin; Rosales, Jesusa L.; Lee, Ki-Young

    2014-01-01

    Rapid neurite remodeling is fundamental to nervous system development and plasticity. It involves neurite extension that is regulated by NGF through PI3K/AKT, p44/42 MAPK and p38 MAPK. It also involves neurite retraction that is regulated by the serine protease, thrombin. However, the intracellular signaling pathway by which thrombin causes neurite retraction is unknown. Using the PC12 neuronal cell model, we demonstrate that thrombin utilizes the PI3K/AKT pathway for neurite retraction in NGF-differentiated cells. Interestingly, however, we found that thrombin enhances NGF-induced neurite extension in differentiating cells. This is achieved through increased and sustained activation of p44/42 MAPK and p38 MAPK. Thus, thrombin elicits opposing effects in differentiated and differentiating cells through activation of distinct signaling pathways: neurite retraction in differentiated cells via PI3K/AKT, and neurite extension in differentiating cells via p44/42 MAPK and p38 MAPK. These findings, which also point to a novel cooperative role between thrombin and NGF, have significant implications in the development of the nervous system and the disease processes that afflicts it as well as in the potential of combined thrombin and NGF therapy for impaired learning and memory, and spinal cord injury which all require neurite extension and remodeling. PMID:25061982

  4. Interferon-β counter-regulates its own pro-apoptotic action by activating p38 MAPK signalling in human SH-SY5Y neuroblastoma cells.

    PubMed

    Dedoni, Simona; Olianas, Maria C; Onali, Pierluigi

    2014-10-01

    Type I interferons (IFNs) induce apoptosis of neuroblastoma cells, but the molecular mechanisms regulating this event have not been completely elucidated. Here, we investigated the role of p38 mitogen activated protein kinase (MAPK) activity, a key regulator of apoptosis and a known modulator of IFN-induced responses in non-neuronal cells. We show that in SH-SY5Y human neuroblastoma cells IFN-β induced a delayed and sustained increase of p38 MAPK activity through a novel mechanism involving the sequential activation of Janus kinase-signal transducer and activator of transcription-1 signalling, enhanced expression of the NADPH oxidase catalytic subunit gp91(phox), increased reactive oxygen species production and stimulation of the MAPK kinase kinase transforming growth factor-β-activated kinase 1. Either blockade of p38 MAPK by the second generation inhibitors BIRB0796 and VX745 or siRNA knockdown of p38α MAPK enhanced IFN-β-induced apoptosis of neuroblastoma cells. Exposure to IFN-β increased the phosphorylation of the small heat shock protein HSP27 at Ser15, Ser78 and Ser82 with a time course similar to p38 MAPK activation and this response was suppressed by either p38α MAPK depletion or pharmacological inhibition of p38 MAPK and MAPK-activated protein kinase 2 (MK2). Either silencing of HSP27 expression by siRNA or MK2 inhibition potentiated IFN-β-induced apoptotic death. These results indicate that IFN-β-induced apoptosis of human SH-SY5Y neuroblastoma cells is associated with a long-lasting up-regulation of p38 MAPK activity, stimulation of MK2 and phosphorylation of the pro-survival protein HSP27. Moreover, the data show that inhibition of p38 MAPK signalling potentiates the anti-neuroblastoma activity of the cytokine, indicating that this pathway mediates a counter-regulatory response.

  5. Apoptotic Effects of Cordycepin Through the Extrinsic Pathway and p38 MAPK Activation in Human Glioblastoma U87MG Cells.

    PubMed

    Baik, Ji-Sue; Mun, Seo-Won; Kim, Kyoung-Sook; Park, Shin-Ji; Yoon, Hyun-Kyoung; Kim, Dong-Hyun; Park, Min-Kyu; Kim, Cheorl-Ho; Lee, Young-Choon

    2016-02-01

    We first demonstrated that cordycepin inhibited cell growth and triggered apoptosis in U87MG cells with wild-type p53, but not in T98G cells with mutant-type p53. Western blot data revealed that the levels of procaspase-8, -3, and Bcl-2 were downregulated in cordycepintreated U87MG cells, whereas the levels of Fas, FasL, Bak, cleaved caspase-3, -8, and cleaved PARP were upregulated, indicating that cordycepin induces apoptosis by activating the death receptor-mediated pathway in U87MG cells. Cordycepin-induced apoptosis could be suppressed by only SB203580, a p38 MAPK-specific inhibitor. These results suggest that cordycepin triggered apoptosis in U87MG cells through p38 MAPK activation and inhibition of the Akt survival pathway. PMID:26597532

  6. Induction of prostaglandin D2 through the p38 MAPK pathway is responsible for the antipruritic activity of sertaconazole nitrate.

    PubMed

    Kaur, Simarna; Sur, Runa; Liebel, Frank T; Southall, Michael D

    2010-10-01

    Prostaglandin D(2) (PGD(2)) is known to have antipruritic activity by suppressing histamine release. However, agents that can topically induce PGD(2) for itch relief are not well established. The antimycotic sertaconazole nitrate (STZ) has been shown to exhibit anti-itch properties; however, the mechanism for this activity has not been elucidated. STZ mitigated degranulation of RBL-2H3 (rat basophilic leukemia) mast cells induced by compound 48/80, a pruritogenic agent known to promote the release of histamine, and augmented PGD(2) production in mast cells and macrophages. Addition of exogenous PGD(2) abrogated compound 48/80-induced degranulation by acting through the prostanoid D receptor 1 (DP1). STZ induced p38 mitogen-activated protein kinase (MAPK) phosphorylation in mast cells and a pharmacological inhibitor of p38 MAPK, SB203580, resulted in the attenuation of PGD(2) levels. Finally, in a murine model of pruritus, the scratching behavior induced by compound 48/80 was mitigated by topical application of STZ. This effect was reversed by the addition of the cyclooxygenase inhibitor, ibuprofen, or a DP1 receptor antagonist (MK0524). Collectively, these results suggest that STZ mediates its anti-itch effects by boosting the antipruritic agent, PGD(2), by the activation of the p38-MAPK pathway. This is the first report to demonstrate a promising approach to topically induce PGD(2) for improving pruritus. PMID:20505747

  7. Secretory pathway retention of mutant prion protein induces p38-MAPK activation and lethal disease in mice

    PubMed Central

    Puig, Berta; Altmeppen, Hermann C.; Ulbrich, Sarah; Linsenmeier, Luise; Krasemann, Susanne; Chakroun, Karima; Acevedo-Morantes, Claudia Y.; Wille, Holger; Tatzelt, Jörg; Glatzel, Markus

    2016-01-01

    Misfolding of proteins in the biosynthetic pathway in neurons may cause disturbed protein homeostasis and neurodegeneration. The prion protein (PrPC) is a GPI-anchored protein that resides at the plasma membrane and may be misfolded to PrPSc leading to prion diseases. We show that a deletion in the C-terminal domain of PrPC (PrPΔ214–229) leads to partial retention in the secretory pathway causing a fatal neurodegenerative disease in mice that is partially rescued by co-expression of PrPC. Transgenic (Tg(PrPΔ214–229)) mice show extensive neuronal loss in hippocampus and cerebellum and activation of p38-MAPK. In cell culture under stress conditions, PrPΔ214–229 accumulates in the Golgi apparatus possibly representing transit to the Rapid ER Stress-induced ExporT (RESET) pathway together with p38-MAPK activation. Here we describe a novel pathway linking retention of a GPI-anchored protein in the early secretory pathway to p38-MAPK activation and a neurodegenerative phenotype in transgenic mice. PMID:27117504

  8. Electromagnetic pulse activated brain microglia via the p38 MAPK pathway.

    PubMed

    Yang, Long-Long; Zhou, Yan; Tian, Wei-Dong; Li, Hai-Juan; Kang-Chu-Li; Miao, Xia; An, Guang-Zhou; Wang, Xiao-Wu; Guo, Guo-Zhen; Ding, Gui-Rong

    2016-01-01

    Previously, we found that electromagnetic pulses (EMP) induced an increase in blood brain barrier permeability and the leakage of albumin from blood into brain tissue. Albumin is known to activate microglia cells. Thus, we hypothesised that microglia activation could occur in the brain after EMP exposure. To test this hypothesis, the morphology and secretory function of microglia cells, including the expression of OX-42 (a marker of microglia activation), and levels of TNF-α, IL-10, IL-1β, and NO were determined in the rat cerebral cortex after EMP exposure. In addition, to examine the signalling pathway of EMP-induced microglia activation, protein and phosphorylated protein levels of p38, JNK and ERK were determined. It was found that the expression of OX-42increased significantly at 1, 6 and 12h (p<0.05) and recovered to the sham group level at 24h after EMP exposure. Levels of NO, TNF-α and IL-10 also changed significantly in vivo and in vitro after EMP exposure. The protein level of p38 and phosphorylated p38 increased significantly after EMP exposure (p<0.05) and recovered to sham levels at 12 and 24h, respectively. Protein and phosphorylated protein levels of ERK and JNK did not change. SB203580 (p38 inhibitor) partly prevented the change in NO, IL-10, IL-1β, TNF-α levels induced by EMP exposure. Taken together, these results suggested that EMP exposure (200kV/m, 200 pulses) could activate microglia in rat brain and affect its secretory function both in vivo and in vitro, and the p38 pathway is involved in this process. PMID:26688329

  9. Electromagnetic pulse activated brain microglia via the p38 MAPK pathway.

    PubMed

    Yang, Long-Long; Zhou, Yan; Tian, Wei-Dong; Li, Hai-Juan; Kang-Chu-Li; Miao, Xia; An, Guang-Zhou; Wang, Xiao-Wu; Guo, Guo-Zhen; Ding, Gui-Rong

    2016-01-01

    Previously, we found that electromagnetic pulses (EMP) induced an increase in blood brain barrier permeability and the leakage of albumin from blood into brain tissue. Albumin is known to activate microglia cells. Thus, we hypothesised that microglia activation could occur in the brain after EMP exposure. To test this hypothesis, the morphology and secretory function of microglia cells, including the expression of OX-42 (a marker of microglia activation), and levels of TNF-α, IL-10, IL-1β, and NO were determined in the rat cerebral cortex after EMP exposure. In addition, to examine the signalling pathway of EMP-induced microglia activation, protein and phosphorylated protein levels of p38, JNK and ERK were determined. It was found that the expression of OX-42increased significantly at 1, 6 and 12h (p<0.05) and recovered to the sham group level at 24h after EMP exposure. Levels of NO, TNF-α and IL-10 also changed significantly in vivo and in vitro after EMP exposure. The protein level of p38 and phosphorylated p38 increased significantly after EMP exposure (p<0.05) and recovered to sham levels at 12 and 24h, respectively. Protein and phosphorylated protein levels of ERK and JNK did not change. SB203580 (p38 inhibitor) partly prevented the change in NO, IL-10, IL-1β, TNF-α levels induced by EMP exposure. Taken together, these results suggested that EMP exposure (200kV/m, 200 pulses) could activate microglia in rat brain and affect its secretory function both in vivo and in vitro, and the p38 pathway is involved in this process.

  10. P38 MAPK inhibitors suppress biomarkers of hypertension end-organ damage, osteopontin and plasminogen activator inhibitor-1.

    PubMed

    Nerurkar, S S; Olzinski, A R; Frazier, K S; Mirabile, R C; O'Brien, S P; Jing, J; Rajagopalan, D; Yue, T L; Willette, R N

    2007-01-01

    The assessment of target organ damage is important in defining the optimal treatment of hypertension and blood pressure-related cardiovascular disease. The aims of the present study were (1) to investigate candidate biomarkers of target organ damage, osteopontin (OPN) and plasminogen activator inhibitor-1 (PAI-1), in models of malignant hypertension with well characterized end-organ pathology; and (2) to evaluate the effects of chronic treatment with a p38 MAPK inhibitor. Gene expression, plasma concentrations, and renal immunohistochemical localization of OPN and PAI-1 were measured in stroke-prone spontaneously hypertensive rats on a salt-fat diet (SFD SHR-SP) and in spontaneously hypertensive rats receiving N(omega)-nitro-L-arginine methyl ester (L-NAME SHR). Plasma concentrations of OPN and PAI-1 increased significantly in SFD SHR-SP and L-NAME SHR as compared with controls, (2.5-4.5-fold for OPN and 2.0-9.0-fold for PAI-1). The plasma levels of OPN and PAI-1 were significantly correlated with the urinary excretion of albumin (p < 0.0001). Elevations in urinary albumin, plasma OPN and PAI-1 were abolished by chronic treatment (4-8 weeks) with a specific p38 MAPK inhibitor, SB-239063AN. OPN immunoreactivity was localized predominantly in the apical portion of tubule epithelium, while PAI-1 immunoreactivity was robust in glomeruli, tubules and renal artery endothelium. Treatment with the p38 MAPK inhibitor significantly reduced OPN and PAI-1 protein expression in target organs. Kidney gene expression was increased for OPN (4.9- and 7.9-fold) and PAI-1 (2.8- and 11.5-fold) in SFD SHR-SP and L-NAME SHR, respectively. In-silico pathway analysis revealed that activation of p38 MAPK was linked to OPN and PAI-1 via SPI, c-fos and c-jun; suggesting that these pathways may play an important role in p38 MAPK-dependent hypertensive renal dysfunction. The results suggest that enhanced OPN and PAI-1 expression reflects end-organ damage in hypertension and that suppression

  11. Infectious bursal disease virus infection induces macrophage activation via p38 MAPK and NF-kappaB pathways.

    PubMed

    Khatri, Mahesh; Sharma, Jagdev M

    2006-06-01

    In the present study, we show that infection with infectious bursal disease virus (IBDV) causes activation of macrophages, the key cells involved in inflammatory and immune-regulatory functions. Exposure of cultured spleen macrophages (SM) from SPF chickens to IBDV resulted in the production of nitric oxide (NO). In addition, there was upregulation of mRNA expression of inducible nitric oxide synthase (iNOS), IL-8 and cyclooxygenase-2 (COX-2). The signal transduction pathways involved in macrophage activation were examined. The role of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-kappaB) was tested by using specific pharmacological inhibitors. Addition of p38 MAPK inhibitor, SB-203580 and NF-kappaB inhibitor Bay 11-7082, suppressed IBDV-induced NO production and mRNA expression of iNOS, IL-8 and COX-2. The results suggest that IBDV uses cellular signal transduction machinery, in particular the p38 MAPK and NF-kappaB pathways, to elicit macrophage activation. The increased production of NO, IL-8 and COX-2 by macrophages may contribute to bursa inflammatory responses commonly seen during the acute IBDV infection.

  12. Anti-Inflammatory Effects of α-Galactosylceramide Analogs in Activated Microglia: Involvement of the p38 MAPK Signaling Pathway

    PubMed Central

    Chung, Young Sun; Park, Seung Bum; Kim, Hee-Sun

    2014-01-01

    Microglial activation plays a pivotal role in the development and progression of neurodegenerative diseases. Thus, anti-inflammatory agents that control microglial activation can serve as potential therapeutic agents for neurodegenerative diseases. Here, we designed and synthesized α-galactosylceramide (α-GalCer) analogs to exert anti-inflammatory effects in activated microglia. We performed biological evaluations of 25 α-GalCer analogs and observed an interesting preliminary structure-activity relationship in their inhibitory influence on NO release and TNF-α production in LPS-stimulated BV2 microglial cells. After identification of 4d and 4e as hit compounds, we further investigated the underlying mechanism of their anti-inflammatory effects using RT-PCR analysis. We confirmed that 4d and 4e regulate the expression of iNOS, COX-2, IL-1β, and IL-6 at the mRNA level and the expression of TNF-α at the post-transcriptional level. In addition, both 4d and 4e inhibited LPS-induced DNA binding activities of NF-κB and AP-1 and phosphorylation of p38 MAPK without affecting other MAP kinases. When we examined the anti-inflammatory effect of a p38 MAPK-specific inhibitor, SB203580, on microglial activation, we observed an identical inhibitory pattern as that of 4d and 4e, not only on NO and TNF-α production but also on the DNA binding activities of NF-κB and AP-1. Taken together, these results suggest that p38 MAPK plays an important role in the anti-inflammatory effects of 4d and 4e via the modulation of NF-κB and AP-1 activities. PMID:24523867

  13. Abrogation of NF-κB signaling in human neutrophils induces neutrophil survival through sustained p38-MAPK activation.

    PubMed

    Langereis, Jeroen D; Raaijmakers, Hanneke A J A; Ulfman, Laurien H; Koenderman, Leo

    2010-10-01

    NF-κB, an important transcription factor in the regulation of cellular inflammation, is one of the prime targets for novel anti-inflammatory therapeutics. Nowadays, anti-inflammatory therapies rely mostly on steroids, which among other effects, inhibit NF-κB activity. However, steroids have only limited efficacy in the treatment on neutrophil-driven diseases, such as COPD. Human neutrophils play an important role in the pathogenesis of COPD, and clearance of these cells by apoptosis is an effective pathway for resolution of inflammation. In this study, we tested the hypothesis that modulation of the NF-κB pathway in human neutrophils affects survival. Importantly, the pharmacological NF-κB inhibitor Bay 11-7082 inhibited NF-κB signaling in human neutrophils as expected. However, we found that complete inhibition of NF-κB activity with 10 μM Bay 11-7082 prolonged neutrophil survival significantly, which was not observed with inhibitors for other signaling pathways. Bay 11-7082-induced neutrophil survival was dependent on p38-MAPK kinase activity, as the p38 kinase activity inhibitor SB203580 abrogated this response completely. Bay 11-7082 induced rapid and sustained p38 activation that correlated with inhibited NF-κB signaling and prolonged neutrophil survival. The precise role of NF-κB in regulation of p38-MAPK activation remains to be established. Under these conditions of survival, the stability of Bcl-xL but not Mcl-1 was enhanced. Although inhibition of NF-κB leads to down-regulation of inflammatory genes in many cell types, our results illustrate that interference with basal NF-κB signaling in neutrophils as a drug target should be used with caution.

  14. Unconjugated Bilirubin exerts Pro-Apoptotic Effect on Platelets via p38-MAPK activation

    PubMed Central

    NaveenKumar, Somanathapura K.; Thushara, Ram M.; Sundaram, Mahalingam S.; Hemshekhar, Mahadevappa; Paul, Manoj; Thirunavukkarasu, Chinnasamy; Basappa; Nagaraju, Ganesh; Raghavan, Sathees C.; Girish, Kesturu S.; Kemparaju, Kempaiah; Rangappa, Kanchugarakoppal S.

    2015-01-01

    Thrombocytopenia is one of the most frequently observed secondary complications in many pathological conditions including liver diseases, where hyperbilirubinemia is very common. The present study sought to find the cause of thrombocytopenia in unconjugated hyperbilirubinemic conditions. Unconjugated bilirubin (UCB), an end-product of heme catabolism, is known to have pro-oxidative and cytotoxic effects at high serum concentration. We investigated the molecular mechanism underlying the pro-apoptotic effect of UCB on human platelets in vitro, and followed it up with studies in phenylhydrazine-induced hyperbilirubinemic rat model and hyperbilirubinemic human subjects. UCB is indeed found to significantly induce platelet apoptotic events including elevated endogenous reactive oxygen species generation, mitochondrial membrane depolarization, increased intracellular calcium levels, cardiolipin peroxidation and phosphatidylserine externalization (p < 0.001) as evident by FACS analysis. The immunoblots show the elevated levels of cytosolic cytochrome c and caspase activation in UCB-treated platelets. Further, UCB is found to induce mitochondrial ROS generation leading to p38 activation, followed by downstream activation of p53, ultimately resulting in altered expression of Bcl-2 and Bax proteins as evident from immunoblotting. All these parameters conclude that elevated unconjugated bilirubin causes thrombocytopenia by stimulating platelet apoptosis via mitochondrial ROS-induced p38 and p53 activation. PMID:26459859

  15. Hydrogen peroxide mediates hyperglycemia-induced invasive activity via ERK and p38 MAPK in human pancreatic cancer

    PubMed Central

    Ma, Jiguang; Li, Xuqi; Xu, Qinhong; Duan, Wanxing; Chen, Xin; Lv, Yunfu; Zhou, Shuang; Wu, Erxi; Ma, Qingyong; Huo, Xiongwei

    2015-01-01

    Diabetes mellitus and pancreatic cancer are intimately related, as approximately 85% of pancreatic cancer patients suffer from glucose intolerance or even diabetes. In this study, we evaluate the underlying mechanism by which hyperglycemia modulates the invasive potential of cancer cells and contributes to their enhanced metastatic behavior. Here we show that hyperglycemia increases the hydrogen peroxide (H2O2) concentration through up-regulation of manganese superoxide dismutase (SOD2) expression, which further activates the ERK and p38 MAPK pathways, as well as the transcription factors NF-κB and AP-1, in a time-dependent manner. The invasion of pancreatic cancer cells resulting from the activation of the H2O2/MAPK axis under high glucose conditions is effectively inhibited by PD 98059 (ERK inhibitor), SB 203580 (p38 MAPK inhibitor), polyethylene glycol-conjugated catalase (PEG-CAT), or the siRNA specific to SOD2. In addition, streptozotocin-treated diabetic nude mice exhibit a stronger tumor invasive ability in renal capsule xenografts which could be suppressed by PEG-CAT treatment. Furthermore, the integrated optical density (IOD) of SOD2 and uPA stainings is higher in the tumor tissues of pancreatic cancer patients with diabetes compared with pancreatic cancer patients with euglycemia. Taken together, our results demonstrate that hyperglycemia enhances cell invasive ability through the SOD2/H2O2/MAPK axis in human pancreatic cancer. Thus, SOD2/H2O2/MAPK axis may represent a promising therapeutic target for pancreatic cancer patients combined with diabetes mellitus. PMID:26439801

  16. Caffeine inhibits UV-mediated NF-kappaB activation in A2058 melanoma cells: an ATM-PKCdelta-p38 MAPK-dependent mechanism.

    PubMed

    Ravi, Dashnamoorthy; Muniyappa, Harish; Das, Kumuda C

    2008-01-01

    Mammalian ultraviolet (UV) radiation response is a gene induction cascade activated by several transcription factors, including NF-kappaB. Although NF-kappaB is induced by UV radiation, the signal transduction mechanism remains relatively unclear. In the present study, we show that UV-induced NF-kappaB activation is mediated by the activation of Ataxia telangiecia mutated (ATM) and protein kinase C (PKC). We also show that caffeine specifically inhibits UV-mediated NF-kappaB activation, but not TNFalpha-mediated NF-kappaB activation. In addition, our study shows that ATM, but not ATM-Rad3-related (ATR) or DNA-dependent protein kinase (DNA-PK) is involved in UV-induced NF-kappaB activation. Because SB203580 (a p38 MAPK inhibitor), or Calphostin C or rottlerin (PKC inhibitors) was able to inhibit UV-mediated NF-kappaB activation, we evaluated whether caffeine could inhibit p38 MAPK or PKC activity. Caffeine or rottlerin inhibited UV-induced phosphorylation of p38 MAPK, but not anisomycin-induced phosphorylation of p38 MAPK, suggesting that p38 MAPK is downstream of PKC. Additionally, caffeine could effectively inhibit UV-induced increases in PKC activity. Taken together, our study demonstrates that caffeine is a potent inhibitor of UV-induced NF-kappaB activation. Additionally, this inhibition occurs due to the inhibitory action of caffeine on ATM and PKC, resulting in the inhibition of p38 MAPK activation.

  17. TNF-α-induced depressive-like phenotype and p38(MAPK) activation are abolished by ascorbic acid treatment.

    PubMed

    Moretti, Morgana; Budni, Josiane; Freitas, Andiara Espíndola; Neis, Vivian Binder; Ribeiro, Camille Mertins; de Oliveira Balen, Grasiela; Rieger, Débora Kurrle; Leal, Rodrigo Bainy; Rodrigues, Ana Lúcia S

    2015-06-01

    We investigated the effects of ascorbic acid on depressive-like behavior induced by tumor necrosis factor (TNF-α) in mice. Additionally, we examined the effects of combined administration of ascorbic acid and antidepressants, MK-801 and 7-nitroindazole in mice exposed or not to TNF-α and the capacity of TNF-α and ascorbic acid to modulate hippocampal and cerebrocortical phosphorylation of extracellular signal-regulated kinase (ERK), p38(MAPK) and c-Jun N-terminal kinase (JNK). In control animals, ascorbic acid reduced the immobility time in the tail suspension test (TST). Unilateral intracerebroventricular administration of TNF-α produced a depressive-like behavior in the TST, and the treatment with ascorbic acid prevented this effect. Sub-effective dose of ascorbic acid combined with sub-effective doses of fluoxetine, imipramine, bupropion, MK-801 or 7-nitroindazole produced a synergistic antidepressant-like effect in mice exposed or not to TNF-α. No treatment caused significant alterations in the locomotor activity of mice. Administration of TNF-α increased the phosphorylation of p38(MAPK) in hippocampus and cerebral cortex, and the treatment with ascorbic acid prevented this effect. Ascorbic acid increased phosphorylation of ERK1 in the hippocampus of saline- and TNF-α-treated animals, however it did not produce alterations in the cerebral cortex. No effects on phosphorylation of ERK2 or JNK were found. The observed effect of ascorbic acid seems to be associated, at least partially, with a reduced p38(MAPK) phosphorylation, activation of the monoaminergic systems as well as inhibition of N-methyl-D-aspartate (NMDA) receptors and nitric oxide (NO) synthesis.

  18. Carbon monoxide alleviates ethanol-induced oxidative damage and inflammatory stress through activating p38 MAPK pathway

    SciTech Connect

    Li, Yanyan; Gao, Chao; Shi, Yanru; Tang, Yuhan; Liu, Liang; Xiong, Ting; Du, Min; Xing, Mingyou; Liu, Liegang; Yao, Ping

    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. 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.

  19. Titanium dioxide nanoparticles stimulate sea urchin immune cell phagocytic activity involving TLR/p38 MAPK-mediated signalling pathway.

    PubMed

    Pinsino, Annalisa; Russo, Roberta; Bonaventura, Rosa; Brunelli, Andrea; Marcomini, Antonio; Matranga, Valeria

    2015-09-28

    Titanium dioxide nanoparticles (TiO2NPs) are one of the most widespread-engineered particles in use for drug delivery, cosmetics, and electronics. However, TiO2NP safety is still an open issue, even for ethical reasons. In this work, we investigated the sea urchin Paracentrotus lividus immune cell model as a proxy to humans, to elucidate a potential pathway that can be involved in the persistent TiO2NP-immune cell interaction in vivo. Morphology, phagocytic ability, changes in activation/inactivation of a few mitogen-activated protein kinases (p38 MAPK, ERK), variations of other key proteins triggering immune response (Toll-like receptor 4-like, Heat shock protein 70, Interleukin-6) and modifications in the expression of related immune response genes were investigated. Our findings indicate that TiO2NPs influence the signal transduction downstream targets of p38 MAPK without eliciting an inflammatory response or other harmful effects on biological functions. We strongly recommend sea urchin immune cells as a new powerful model for nano-safety/nano-toxicity investigations without the ethical normative issue.

  20. Titanium dioxide nanoparticles stimulate sea urchin immune cell phagocytic activity involving TLR/p38 MAPK-mediated signalling pathway

    PubMed Central

    Pinsino, Annalisa; Russo, Roberta; Bonaventura, Rosa; Brunelli, Andrea; Marcomini, Antonio; Matranga, Valeria

    2015-01-01

    Titanium dioxide nanoparticles (TiO2NPs) are one of the most widespread-engineered particles in use for drug delivery, cosmetics, and electronics. However, TiO2NP safety is still an open issue, even for ethical reasons. In this work, we investigated the sea urchin Paracentrotus lividus immune cell model as a proxy to humans, to elucidate a potential pathway that can be involved in the persistent TiO2NP-immune cell interaction in vivo. Morphology, phagocytic ability, changes in activation/inactivation of a few mitogen-activated protein kinases (p38 MAPK, ERK), variations of other key proteins triggering immune response (Toll-like receptor 4-like, Heat shock protein 70, Interleukin-6) and modifications in the expression of related immune response genes were investigated. Our findings indicate that TiO2NPs influence the signal transduction downstream targets of p38 MAPK without eliciting an inflammatory response or other harmful effects on biological functions. We strongly recommend sea urchin immune cells as a new powerful model for nano-safety/nano-toxicity investigations without the ethical normative issue. PMID:26412401

  1. Tumor suppressor gene ING3 induces cardiomyocyte hypertrophy via inhibition of AMPK and activation of p38 MAPK signaling.

    PubMed

    Wang, Jiaojiao; Liu, Zhiping; Feng, Xiaojun; Gao, Si; Xu, Suowen; Liu, Peiqing

    2014-11-15

    Cardiac hypertrophy, an adaptive growth process that occurs in response to various pathophysiological stimuli, constitutes an important risk factor for the development of heart failure. However, the molecular mechanisms that regulate this cardiac growth response are not completely understood. Here we revealed that ING3 (inhibitor of growth family, member 3), a type II tumor suppressor, plays a critical role in the regulation of cardiac hypertrophy. ING3 expression was present in relatively high abundance in the heart, and was prominently upregulated in hypertrophic agonists angiotensin II (Ang II), phenylephrine (PE), or isoproterenol (ISO)-stimulated cardiomyocytes and in hearts of rat undergoing abdominal aortic constriction (AAC) surgery. In cardiomyocytes, overexpression of ING3 caused an increase in ANP, BNP and β-MHC mRNA levels and cell surface area, while depletion of ING3 attenuated PE-induced cardiomyocyte hypertrophy. Mechanistically, we have demonstrated that overexpression of ING3 could inactivate the AMPK and activate the canonical p38 MAPK signaling. Remarkably, AMPK agonist AICAR or p38 MAPK inhibitor SB203580 abrogated ING3-induced hypertrophic response in cardiomyocytes. In summary, our data disclose a novel role of ING3 as an inducer of pathological cardiac hypertrophy, suggesting that silencing of ING3 may be explored as a potential therapeutic target in preventing cardiac hypertrophy.

  2. Stress activated protein kinases, JNKs and p38 MAPK, are differentially activated in ganglia and heart of land snail Helix lucorum (L.) during seasonal hibernation and arousal.

    PubMed

    Michaelidis, Basile; Hatzikamari, Maria; Antoniou, Vassiliki; Anestis, Andreas; Lazou, Antigone

    2009-06-01

    The present work aimed to investigate the phosphorylation and hence activation of stress activated protein kinases, p38 MAPK and JNKs in the tissues of the snail Helix lucorum during seasonal hibernation. Snails were put in large glass boxes, which were placed outdoors so that they were exposed to natural conditions of light and temperature. Phosphorylation and hence activation of JNKs and p38 MAPK was determined in both heart and ganglia. Deep hibernation caused significant increases in the levels of the phosphorylated form of JNK and p38-MAPK in both heart and ganglia. Phosphorylation of JNK remained elevated in the ganglia or increased after a transient drop in the heart, when the snails were prepared for arousal. In addition, phosphorylation of p38-MAPK was further increased in the heart during this period. These data support the conclusion that MAPK signalling cascade might contribute in the physiological and biochemical remodelling in the tissues of land snails during hibernation and upon preparation for arousal.

  3. ROCK activity affects IL-1-induced signaling possibly through MKK4 and p38 MAPK in Caco-2 cells.

    PubMed

    Banerjee, Sayantan; McGee, Dennis W

    2016-09-01

    Elevated levels of interleukin-1 (IL-1) accompany inflammatory bowel disease. IL-1-stimulated intestinal epithelial cells can secrete potent chemokines like CXCL8 to exacerbate inflammation. Previously, we found that inhibiting the Rho-associated kinase (ROCK) could inhibit IL-1- or TNF-α-induced CXCL8 secretion by the Caco-2 colonic epithelial cell line. This ROCK inhibition did not affect IκBα phosphorylation and degradation, but suppressed the phosphorylation of c-Jun N-terminal kinase (JNK). Therefore, ROCK must play an important role in epithelial cell CXCL8 responses through an effect on the JNK signaling pathway. Here, we extend these studies by showing that inhibiting ROCK suppressed the IL-1-induced phosphorylation of MKK4, a known activator of JNK, but not MKK7. Yet, ROCK inhibition had no significant effect on the IL-1-induced phosphorylation of extracellular-signal-regulated kinase (ERK) 1/2. Inhibiting ROCK also suppressed the phosphorylation of p38 MAPK after IL-1 stimulation, but this inhibition had no significant effect on the stability of CXCL8 messenger RNA (mRNA) after IL-1 stimulation. These results suggest that ROCK may be important in IL-1-induced signaling through MKK4 to JNK and the activation of p38 MAPK. Finally, inhibiting ROCK in IL-1 and TNF-α co-stimulated Caco-2 cells also resulted in a significant suppression of CXCL8 secretion and mRNA levels suggesting that inhibiting ROCK may be a mechanism to inhibit the overall response of epithelial cells to both cytokines. These studies indicate a novel signaling event, which could provide a target for suppressing intestinal epithelial cells (IEC) chemokine responses involved in mucosal inflammation.

  4. ROCK activity affects IL-1-induced signaling possibly through MKK4 and p38 MAPK in Caco-2 cells.

    PubMed

    Banerjee, Sayantan; McGee, Dennis W

    2016-09-01

    Elevated levels of interleukin-1 (IL-1) accompany inflammatory bowel disease. IL-1-stimulated intestinal epithelial cells can secrete potent chemokines like CXCL8 to exacerbate inflammation. Previously, we found that inhibiting the Rho-associated kinase (ROCK) could inhibit IL-1- or TNF-α-induced CXCL8 secretion by the Caco-2 colonic epithelial cell line. This ROCK inhibition did not affect IκBα phosphorylation and degradation, but suppressed the phosphorylation of c-Jun N-terminal kinase (JNK). Therefore, ROCK must play an important role in epithelial cell CXCL8 responses through an effect on the JNK signaling pathway. Here, we extend these studies by showing that inhibiting ROCK suppressed the IL-1-induced phosphorylation of MKK4, a known activator of JNK, but not MKK7. Yet, ROCK inhibition had no significant effect on the IL-1-induced phosphorylation of extracellular-signal-regulated kinase (ERK) 1/2. Inhibiting ROCK also suppressed the phosphorylation of p38 MAPK after IL-1 stimulation, but this inhibition had no significant effect on the stability of CXCL8 messenger RNA (mRNA) after IL-1 stimulation. These results suggest that ROCK may be important in IL-1-induced signaling through MKK4 to JNK and the activation of p38 MAPK. Finally, inhibiting ROCK in IL-1 and TNF-α co-stimulated Caco-2 cells also resulted in a significant suppression of CXCL8 secretion and mRNA levels suggesting that inhibiting ROCK may be a mechanism to inhibit the overall response of epithelial cells to both cytokines. These studies indicate a novel signaling event, which could provide a target for suppressing intestinal epithelial cells (IEC) chemokine responses involved in mucosal inflammation. PMID:27173611

  5. Noncanonical Wnt-4 signaling enhances bone regeneration of mesenchymal stem cells in craniofacial defects through activation of p38 MAPK.

    PubMed

    Chang, Jia; Sonoyama, Wataru; Wang, Zhuo; Jin, Qiming; Zhang, Chengfei; Krebsbach, Paul H; Giannobile, William; Shi, Songtao; Wang, Cun-Yu

    2007-10-19

    Mesenchymal stem cells (MSCs) are multipotent cells that can be differentiated into osteoblasts and provide an excellent cell source for bone regeneration and repair. Recently, the canonical Wnt/beta-catenin signaling pathway has been found to play a critical role in skeletal development and osteogenesis, implying that Wnts can be utilized to improve de novo bone formation mediated by MSCs. However, it is unknown whether noncanonical Wnt signaling regulates osteogenic differentiation. Here, we find that Wnt-4 enhanced in vitro osteogenic differentiation of MSCs isolated from human adult craniofacial tissues and promoted bone formation in vivo. Whereas Wnt-4 did not stabilize beta-catenin, it activated p38 MAPK in a novel noncanonical signaling pathway. The activation of p38 was dependent on Axin and was required for the enhancement of MSC differentiation by Wnt-4. Moreover, using two different models of craniofacial bone injury, we found that MSCs genetically engineered to express Wnt-4 enhanced osteogenesis and improved the repair of craniofacial defects in vivo. Taken together, our results reveal that noncanonical Wnt signaling could also play a role in osteogenic differentiation. Wnt-4 may have a potential use in improving bone regeneration and repair of craniofacial defects.

  6. p38 Mitogen-Activated Protein Kinase (MAPK) Increases Arginase Activity and Contributes to Endothelial Dysfunction in Corpora Cavernosa from Angiotensin-II Treated Mice

    PubMed Central

    Toque, Haroldo A.; Romero, Maritza J.; Tostes, Rita C.; Shatanawi, Alia; Chandra, Surabhi; Carneiro, Zidonia N.; Inscho, Edward W.; Webb, R. Clinton; Caldwell, Ruth B.; Caldwell, R. William

    2010-01-01

    Introduction Angiotensin II (AngII) activates p38 mitogen-activated protein kinase (MAPK) and elevates arginase activity in endothelial cells. Upregulation of arginase activity has been implicated in endothelial dysfunction by reducing NO bioavailability. However, signaling pathways activated by AngII in the penis are largely unknown. Aim We hypothesized that activation of p38 MAPK increases arginase activity and thus impairs penile vascular function in AngII-treated mice. Methods Male C57BL/6 mice were implanted with osmotic minipumps containing saline or AngII (42 μg/kg/h) for 14 days and co-treated with p38 MAPK inhibitor, SB 203580 (5 μg/kg/day), beginning 2 days before minipump implantation. Systolic blood pressure (SBP) was measured. Corpus cavernosum (CC) tissue was used for vascular functional studies and protein expression levels of p38 MAPK, arginase and constitutive NOS, and arginase activity. Main Outcome Measures Arginase expression and activity; expression of phospho-p38 MAPK, -eNOS and nNOS proteins; endothelium-dependent and nitrergic nerve-mediated relaxations were determined in CC from control and AngII-infused mice. Results AngII increased SBP (22%) and increased CC arginase activity and expression (~2-fold), and phosphorylated P38 MAPK levels (30%) over control. Treatment with SB 203580 prevented these effects. Endothelium-dependent NO-mediated relaxation to acetylcholine was significantly reduced by AngII and this effect was prevented by SB 203580 (P<0.01). AngII (2-week) did not alter nitrergic function. However, SB 203580 significantly increased nitrergic relaxation in both control and AngII tissue at lower frequencies. Maximum contractile responses for phenylephrine and electrical field stimulation were increased by AngII (56% and 171%, respectively), and attenuated by SB 203580 treated. AngII treatment also decreased eNOS phosphorylation at Ser-1177 compared to control. Treatment with SB 203580 prevented all these changes. Conclusion p38

  7. Differential Activation of Mitogen-Activated Protein Kinases, ERK 1/2, p38(MAPK) and JNK p54/p46 During Postnatal Development of Rat Hippocampus.

    PubMed

    Costa, Ana Paula; Lopes, Mark William; Rieger, Débora K; Barbosa, Sabrina Giovana Rocha; Gonçalves, Filipe Marques; Xikota, João Carlos; Walz, Roger; Leal, Rodrigo B

    2016-05-01

    Mitogen-activated protein kinases (MAPKs) are a group of serine-threonine kinases, including p38(MAPK), ERK 1/2 and JNK p54/p46, activated by phosphorylation in response to extracellular stimuli. The early postnatal period is characterized by significant changes in brain structure as well as intracellular signaling. In the hippocampus MAPKs have been involved in the modulation of development and neural plasticity. However, the temporal profile of MAPK activation throughout the early postnatal development is incomplete. An understanding of this profile is important since slight changes in the activity of these enzymes, in response to environmental stress in specific developmental windows, might alter the course of development. The present study was undertaken to investigate the hippocampal differential activation of MAPK during postnatal period. MAPK activation and total content were evaluated by Western blotting of hippocampal tissue obtained from male Wistar rats at postnatal days (P) 1, 4, 7, 10, 14, 21, 30 and 60. The total content and phosphorylation of each MAPK was expressed as mean ± SEM and then calculates as a percentile compared to P1 (set at 100 %). The results showed: (1) phosphorylation peaks of p38(MAPK) at PN4 (p = 0.036) and PN10 to PN60; (2) phosphorylation of ERK1 and ERK2 were increased with age (ERK1 p = 0.0000005 and ERK2 p = 0.003); (3) phosphorylation profile of JNK p54/p46 was not changed during the period analyzed (JNKp56 p = 0.716 and JNKp46 p = 0.192). Therefore, the activity profile of ERK 1/2 and p38(MAPK) during postnatal development of rat hippocampus are differentially regulated. Our results demonstrate that ERK 1/2 and p38(MAPK) are dynamically regulated during postnatal neurodevelopment, suggesting temporal correlation of MAPK activity with critical periods when programmed cell death and synaptogenesis are occurring. This suggests an important role for these MAPKs in postnatal development of rat hippocampus.

  8. Characterization of p38 MAPKs from orange-spotted grouper, Epinephelus coioides involved in SGIV infection.

    PubMed

    Cai, Jia; Huang, Youhua; Wei, Shina; Huang, Xiaohong; Ye, Fuzhou; Fu, Jing; Qin, Qiwei

    2011-12-01

    p38 mitogen-activated protein kinases (MAPKs) are broadly expressed signaling molecules that involves in the regulation of cellular responsible for various extracellular stimuli. In this study, three p38 MAPK genes (Ec-p38a, p38b and p38β) were cloned from grouper, Epinephelus coioides and their characteristics were investigated in vitro. Although Ec-p38a, p38b and p38β showed high homologies to other fish p38a MPAK, p38b MAPK and p38β MAPK, respectively, they all contained the conserved structures of Thr-Gly-Tyr (TGY) motif and substrate binding site Ala-Thr-Arg-Trp (ATRW). Phylogenetic analysis indicated that Ec-p38a, p38b and p38β are more closely related to those from fish than mammals. The tissue distribution patterns of Ec-p38a, p38b and p38β were different, and Ec-p38β was up-regulated most obviously in head kidney after Singapore grouper iridovirus (SGIV) infection. Overexpression of Ec-p38β in FHM cells delayed the occurrence of CPE induced by SGIV infection. Further analysis indicated that overexpression of Ec-p38β inhibited viral gene transcription and protein synthesis, as well as SGIV induced typical apoptosis in fish cells. Taken together, our data indicated that Ec-p38β played a crucial role in regulating apoptosis and virus replication during iridovirus infection.

  9. Sphingosine kinase inhibitor suppresses IL-18-induced interferon-gamma production through inhibition of p38 MAPK activation in human NK cells

    SciTech Connect

    Cheon, Soyoung; Song, Seok Bean; Jung, Minkyung; Park, Yoorim; Bang, Jung-Wook; Kim, Tae Sung; Park, Hyunjeong; Kim, Cherl-hyun; Yang, Yool-hee; Bang, Sa Ik; Cho, Daeho

    2008-09-12

    Natural killer (NK) cells play an important role in the innate immune response. Interleukin-18 (IL-18) is a well-known interferon-gamma (IFN-{gamma} inducing factor, which stimulates immune response in NK and T cells. Sphingosine kinase (SPHK) catalyzes the formation of sphingosine 1-phosphate (S1P), which acts as a second messenger to function as an anti-apoptotic factor and proliferation stimulator of immune cells. In this study, to elucidate whether SPHK is involved in IL-18-induced IFN-{gamma} production, we measured IL-18-induced IFN-{gamma} production after pre-treatment with SPHK inhibitor (SKI) in NK-92MI cells. We found that IL-18-induced IFN-{gamma} expression was blocked by SKI pre-treatment in both mRNA and protein levels. In addition, the increased IFN-{gamma} production by stimulation with IL-18 is mediated through both SPHK and p38 MAPK. To determine the upstream signals of SKI and p38 MAPK in IL-18-induced IFN-{gamma} production, phosphorylation levels of p38 MAPK was measured after SKI pre-treatment. As a result, inhibition of SPHK by SKI blocked phosphorylation of p38 MAPK, showing that SPHK activation by IL-18 is an upstream signal of p38 MAPK activation. Inhibition of SPHK by SKI also inhibited IL-18-induced IFN-{gamma} production in human primary NK cells. In conclusion, SPHK activation is an essential factor for IL-18-induced IFN-{gamma} production via p38 MAPK.

  10. Mammary gland specific expression of Brk/PTK6 promotes delayed involution and tumor formation associated with activation of p38 MAPK

    PubMed Central

    2011-01-01

    Introduction Protein tyrosine kinases (PTKs) are frequently overexpressed and/or activated in human malignancies, and regulate cancer cell proliferation, cellular survival, and migration. As such, they have become promising molecular targets for new therapies. The non-receptor PTK termed breast tumor kinase (Brk/PTK6) is overexpressed in approximately 86% of human breast tumors. The role of Brk in breast pathology is unclear. Methods We expressed a WAP-driven Brk/PTK6 transgene in FVB/n mice, and analyzed mammary glands from wild-type (wt) and transgenic mice after forced weaning. Western blotting and immunohistochemistry (IHC) studies were conducted to visualize markers of mammary gland involution, cell proliferation and apoptosis, as well as Brk, STAT3, and activated p38 mitogen-activated protein kinase (MAPK) in mammary tissues and tumors from WAP-Brk mice. Human (HMEC) or mouse (HC11) mammary epithelial cells were stably or transiently transfected with Brk cDNA to assay p38 MAPK signaling and cell survival in suspension or in response to chemotherapeutic agents. Results Brk-transgenic dams exhibited delayed mammary gland involution and aged mice developed infrequent tumors with reduced latency relative to wt mice. Consistent with delayed involution, mammary glands of transgenic animals displayed decreased STAT3 phosphorylation, a marker of early-stage involution. Notably, p38 MAPK, a pro-survival signaling mediator downstream of Brk, was activated in mammary glands of Brk transgenic relative to wt mice. Brk-dependent signaling to p38 MAPK was recapitulated by Brk overexpression in the HC11 murine mammary epithelial cell (MEC) line and human MEC, while Brk knock-down in breast cancer cells blocked EGF-stimulated p38 signaling. Additionally, human or mouse MECs expressing Brk exhibited increased anchorage-independent survival and resistance to doxorubicin. Finally, breast tumor biopsies were subjected to IHC analysis for co-expression of Brk and phospho-p38 MAPK

  11. Constitutive activation of p38 MAPK in tumor cells contributes to osteolytic bone lesions in multiple myeloma.

    PubMed

    Yang, J; He, J; Wang, J; Cao, Y; Ling, J; Qian, J; Lu, Y; Li, H; Zheng, Y; Lan, Y; Hong, S; Matthews, J; Starbuck, M W; Navone, N M; Orlowski, R Z; Lin, P; Kwak, L W; Yi, Q

    2012-09-01

    Bone destruction is a hallmark of multiple myeloma and affects more than 80% of patients. However, current therapy is unable to completely cure and/or prevent bone lesions. Although it is accepted that myeloma cells mediate bone destruction by inhibition of osteoblasts and activation of osteoclasts, the underlying mechanism is still poorly understood. This study demonstrates that constitutive activation of p38 mitogen-activated protein kinase in myeloma cells is responsible for myeloma-induced osteolysis. Our results show that p38 is constitutively activated in most myeloma cell lines and primary myeloma cells from patients. Myeloma cells with high/detectable p38 activity, but not those with low/undetectable p38 activity, injected into severe combined immunodeficient (SCID) or SCID-hu mice caused bone destruction. Inhibition or knockdown of p38 in human myeloma reduced or prevented myeloma-induced osteolytic bone lesions without affecting tumor growth, survival, or homing to bone. Mechanistic studies showed that myeloma cell p38 activity inhibited osteoblastogenesis and bone formation and activated osteoclastogenesis and bone resorption in myeloma-bearing SCID mice. This study elucidates a novel molecular mechanism-activation of p38 signaling in myeloma cells-by which myeloma cells induce osteolytic bone lesions, and indicates that targeting myeloma cell p38 may be a viable approach to treating or preventing myeloma bone disease. PMID:22425892

  12. Constitutive activation of p38 MAPK in tumor cells contributes to osteolytic bone lesions in multiple myeloma

    PubMed Central

    Yang, Jing; He, Jin; Wang, Ji; Cao, Yabing; Ling, Jianhua; Qian, Jianfei; Lu, Yong; Li, Haiyan; Zheng, Yuhuan; Lan, Yongsheng; Hong, Sungyoul; Matthews, Jairo; Starbuck, Michael W; Navone, Nora M; Orlowski, Robert Z.; Lin, Pei; Kwak, Larry W.; Yi, Qing

    2012-01-01

    Bone destruction is a hallmark of multiple myeloma and affects more than 80% of patients. However, current therapy is unable to completely cure and/or prevent bone lesions. Although it is accepted that myeloma cells mediate bone destruction by inhibition of osteoblasts and activation of osteoclasts, the underlying mechanism is still poorly understood. This study demonstrates that constitutive activation of p38 mitogen-activated protein kinase in myeloma cells is responsible for myeloma-induced osteolysis. Our results show that p38 is constitutively activated in most myeloma cell lines and primary myeloma cells from patients. Myeloma cells with high/detectable p38 activity, but not those with low/undetectable p38 activity, injected into SCID or SCID-hu mice caused bone destruction. Inhibition or knockdown of p38 in human myeloma reduced or prevented myeloma-induced osteolytic bone lesions without affecting tumor growth, survival, or homing to bone. Mechanistic studies showed that myeloma cell p38 activity inhibited osteoblastogenesis and bone formation and activated osteoclastogenesis and bone resorption in myeloma-bearing SCID mice. This study elucidates a novel molecular mechanism—sactivation of p38 signaling in myeloma cells—by which myeloma cells induce osteolytic bone lesions and indicates that targeting myeloma cell p38 may be a viable approach to treating or preventing myeloma bone disease. PMID:22425892

  13. Role of P38 MAPK on MMP Activity in Photothrombotic Stroke Mice as Measured using an Ultrafast MMP Activatable Probe

    PubMed Central

    Chang, Di; Wang, Yuan-Cheng; Bai, Ying-Ying; Lu, Chun-Qiang; Xu, Ting-Ting; Zhu, Lei; Ju, Shenghong

    2015-01-01

    Matrix metalloproteinases (MMPs) exert a dual effect in ischemic stroke and thus represent an ideal target for detection and therapy. However, to date, all clinical trials of MMP inhibitors have failed, and alternative drug candidates and therapeutic targets are urgently required. Nonetheless, further investigations are limited by the lack of non-invasive imaging techniques. Here, we report a novel, fast and ultrasensitive MMP activatable optical imaging probe for the dynamic visualization of MMP activity in photothrombotic stroke mice. This probe provides a significant signal enhancement in as little as 15 min, with the highest signal intensity occurring at 1 h post-injection, and shows high sensitivity in measuring MMP activity alterations, which makes it specifically suitable for the real-time visualization of MMP activity and drug discovery in preclinical research. Moreover, using this probe, we successfully demonstrate that the regulation of the p38 mitogen-activated protein kinase (MAPK) signal pathway is capable of modulating MMP activity after stroke, revealing a novel regulatory mechanism of postischemic brain damage and overcoming the limitations of traditional therapeutic strategies associated with MMP inhibitors by using a non-invasive molecular imaging method. PMID:26581247

  14. Notoginsenoside Rb1 inhibits activation of ERK and p38 MAPK pathways induced by hypoxia and hypercapnia

    PubMed Central

    QIU, XIAOXIAO; ZHENG, MENGXIAO; SONG, DONG; HUANG, LINJING; TANG, LANLAN; YING, LEI; WANG, WANTIE

    2016-01-01

    The aim of the present study was to investigate the effect of notoginsenoside Rb1 (Rb1) on the ERK and p38 MAPK pathways in primary cultured pulmonary arterial smooth muscle cells (PASMCs) exposed to hypoxia and hypercapnia, in order to elucidate the mechanism underlying the effect of Rb1 on hypoxia and hypercapnia-induced pulmonary vasoconstriction (HHPV). PASMCs were isolated from Sprague-Dawley rats. The cells were divided into five groups: Normal (N), hypoxia and hypercapnia (H), RbL, RbM and RbH groups. N group cells were cultured under 5% CO2 and 21% O2. H, RbL, RbM and RbH groups were cultured under 6% CO2 and 1% O2. Prior to the hypoxia and hypercapnia exposure, RbL, RbM and RbH groups were treated with 8, 40 and 100 mg/ml Rb1 for 30 min, respectively. Phosphorylated extracellular signal-regulated kinase (P-ERK) and P-p38 protein, and ERK1/2 and p38 mRNA expression levels were detected using western blot and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analyses, respectively. The correlations between P-ERK protein and ERK1/2 mRNA, and between P-p38 protein and p38 mRNA were evaluated. Results of western blot and RT-PCR showed hypoxia and hypercapnia increased P-ERK and P-p38 protein, and ERK1/2 mRNA, respectively (P<0.05). Rb1 suppressed the increased P-ERK and P-p38 protein, and ERK1/2 and p38 mRNA by hypoxia and hypercapnia (P<0.05). P-ERK protein was positively correlated with ERK1 (r=0.5, P<0.01) and ERK2 mRNA (r=0.977, P<0.01). P-p38 protein was positively correlated with p38 mRNA (r=0.884, P<0.01). Thus, the present results indicate that Rb1 may ameliorate HHPV by suppressing ERK and p38 pathways. The study provides an experimental basis for investigating the clinical use of Rb1 in the management of HHPV-related disorders. PMID:27313674

  15. p38 MAPK Signaling in Postnatal Tendon Growth and Remodeling

    PubMed Central

    Schwartz, Andrew J.; Sarver, Dylan C.; Sugg, Kristoffer B.; Dzierzawski, Justin T.; Gumucio, Jonathan P.; Mendias, Christopher L.

    2015-01-01

    Tendon is a dynamic tissue whose structure and function is influenced by mechanical loading, but little is known about the fundamental mechanisms that regulate tendon growth and remodeling in vivo. Data from cultured tendon fibroblasts indicated that the p38 MAPK pathway plays an important role in tendon fibroblast proliferation and collagen synthesis in vitro. To gain greater insight into the mechanisms of tendon growth, and explore the role of p38 MAPK signaling in this process, we tested the hypotheses that inducing plantaris tendon growth through the ablation of the synergist Achilles tendon would result in rapid expansion of a neotendon matrix surrounding the original tendon, and that treatment with the p38 MAPK inhibitor SB203580 would prevent this growth. Rats were treated with vehicle or SB203580, and subjected to synergist ablation by bilateral tenectomy of the Achilles tendon. Changes in histological and biochemical properties of plantaris tendons were analyzed 3, 7, or 28 days after overload, and comparisons were made to non-overloaded animals. By 28 days after overload, tendon mass had increased by 30% compared to non-overloaded samples, and cross-sectional area (CSA) increased by around 50%, with most of the change occurring in the neotendon. The expansion in CSA initially occurred through the synthesis of a hyaluronic acid rich matrix that was progressively replaced with mature collagen. Pericytes were present in areas of active tendon growth, but never in the original tendon ECM. Inhibition of p38 MAPK resulted in a profound decrease in IL6 expression, and had a modest effect on the expression of other ECM and cell proliferation genes, but had a negligible impact on overall tendon growth. The combined results from this study provided novel insights into tendon mechanobiology, and suggest that p38 MAPK signaling does not appear to be necessary for tendon growth in vivo. PMID:25768932

  16. Role of p38 MAPK activation and mitochondrial cytochrome-c release in allicin-induced apoptosis in SK-N-SH cells.

    PubMed

    Zhuang, Jianhui; Li, Yu; Chi, Yufen

    2016-04-01

    Here, we investigate the apoptotic effect of allicin, the predominant component of freshly crushed garlic, on neuroblastoma cells. In this paper, the authors have first assessed the effect of allicin on human neuroblastoma SK-N-SH cells and then investigated the underlying mechanism. The results indicate that allicin suppresses SK-N-SH cell growth in a dose-dependent and time-dependent manner and that 5 μmol/l of allicin leads to a significant increase in apoptotic rate with annexin-V/PI double staining. Western blot analysis shows that treatment with allicin-induced apoptosis through activation of caspases-3 and 9. Phosphorylation of p38 MAPK contributes to allicin-induced apoptosis upstream of caspase activation. Using p38 MAPK inhibitor, the authors discovered that p38 MAPK activation subsequently induces the release of cytochrome-c from mitochondria into the cytosol. Taken together, the results demonstrate that allicin can activate the p38 MAPK pathway, which leads to mitochondrial release of cytochrome-c, thus inducing SK-N-SH cell apoptosis. Overall, this study suggests that allicin may be used as one of the novel pharmacological treatment strategies in neuroblastoma. PMID:26771864

  17. High Glucose-Induced Oxidative Stress Mediates Apoptosis and Extracellular Matrix Metabolic Imbalances Possibly via p38 MAPK Activation in Rat Nucleus Pulposus Cells.

    PubMed

    Cheng, Xiaofei; Ni, Bin; Zhang, Feng; Hu, Ying; Zhao, Jie

    2016-01-01

    Objectives. To investigate whether high glucose-induced oxidative stress is implicated in apoptosis of rat nucleus pulposus cells (NPCs) and abnormal expression of critical genes involved in the metabolic balance of extracellular matrix (ECM). Methods. NPCs were cultured with various concentrations of glucose to detect cell viability and apoptosis. Cells cultured with high glucose (25 mM) were untreated or pretreated with N-acetylcysteine or a p38 MAPK inhibitor SB 202190. Reactive oxygen species (ROS) production was evaluated. Activation of p38 MAPK was measured by Western blot. The expression of ECM metabolism-related genes, including type II collagen, aggrecan, SRY-related high-mobility-group box 9 (Sox-9), matrix metalloproteinase 3 (MMP-3), and tissue inhibitor of metalloproteinase 1 (TIMP-1), was analyzed by semiquantitative RT-PCR. Results. High glucose reduced viability of NPCs and induced apoptosis. High glucose resulted in increased ROS generation and p38 MAPK activation. In addition, it negatively regulated the expression of type II collagen, aggrecan, Sox-9, and TIMP-1 and positively regulated MMP-3 expression. These results were changed by pretreatment with N-acetylcysteine or SB 202190. Conclusions. High glucose might promote apoptosis of NPCs, trigger ECM catabolic pathways, and inhibit its anabolic activities, possibly through a p38 MAPK-dependent oxidative stress mechanism. PMID:27635402

  18. High Glucose-Induced Oxidative Stress Mediates Apoptosis and Extracellular Matrix Metabolic Imbalances Possibly via p38 MAPK Activation in Rat Nucleus Pulposus Cells

    PubMed Central

    Cheng, Xiaofei; Ni, Bin; Zhang, Feng; Hu, Ying

    2016-01-01

    Objectives. To investigate whether high glucose-induced oxidative stress is implicated in apoptosis of rat nucleus pulposus cells (NPCs) and abnormal expression of critical genes involved in the metabolic balance of extracellular matrix (ECM). Methods. NPCs were cultured with various concentrations of glucose to detect cell viability and apoptosis. Cells cultured with high glucose (25 mM) were untreated or pretreated with N-acetylcysteine or a p38 MAPK inhibitor SB 202190. Reactive oxygen species (ROS) production was evaluated. Activation of p38 MAPK was measured by Western blot. The expression of ECM metabolism-related genes, including type II collagen, aggrecan, SRY-related high-mobility-group box 9 (Sox-9), matrix metalloproteinase 3 (MMP-3), and tissue inhibitor of metalloproteinase 1 (TIMP-1), was analyzed by semiquantitative RT-PCR. Results. High glucose reduced viability of NPCs and induced apoptosis. High glucose resulted in increased ROS generation and p38 MAPK activation. In addition, it negatively regulated the expression of type II collagen, aggrecan, Sox-9, and TIMP-1 and positively regulated MMP-3 expression. These results were changed by pretreatment with N-acetylcysteine or SB 202190. Conclusions. High glucose might promote apoptosis of NPCs, trigger ECM catabolic pathways, and inhibit its anabolic activities, possibly through a p38 MAPK-dependent oxidative stress mechanism.

  19. High Glucose-Induced Oxidative Stress Mediates Apoptosis and Extracellular Matrix Metabolic Imbalances Possibly via p38 MAPK Activation in Rat Nucleus Pulposus Cells

    PubMed Central

    Cheng, Xiaofei; Ni, Bin; Zhang, Feng; Hu, Ying

    2016-01-01

    Objectives. To investigate whether high glucose-induced oxidative stress is implicated in apoptosis of rat nucleus pulposus cells (NPCs) and abnormal expression of critical genes involved in the metabolic balance of extracellular matrix (ECM). Methods. NPCs were cultured with various concentrations of glucose to detect cell viability and apoptosis. Cells cultured with high glucose (25 mM) were untreated or pretreated with N-acetylcysteine or a p38 MAPK inhibitor SB 202190. Reactive oxygen species (ROS) production was evaluated. Activation of p38 MAPK was measured by Western blot. The expression of ECM metabolism-related genes, including type II collagen, aggrecan, SRY-related high-mobility-group box 9 (Sox-9), matrix metalloproteinase 3 (MMP-3), and tissue inhibitor of metalloproteinase 1 (TIMP-1), was analyzed by semiquantitative RT-PCR. Results. High glucose reduced viability of NPCs and induced apoptosis. High glucose resulted in increased ROS generation and p38 MAPK activation. In addition, it negatively regulated the expression of type II collagen, aggrecan, Sox-9, and TIMP-1 and positively regulated MMP-3 expression. These results were changed by pretreatment with N-acetylcysteine or SB 202190. Conclusions. High glucose might promote apoptosis of NPCs, trigger ECM catabolic pathways, and inhibit its anabolic activities, possibly through a p38 MAPK-dependent oxidative stress mechanism. PMID:27635402

  20. A novel synthetic compound MCAP suppresses LPS-induced murine microglial activation in vitro via inhibiting NF-kB and p38 MAPK pathways

    PubMed Central

    Kim, Byung-Wook; More, Sandeep Vasant; Yun, Yo-Sep; Ko, Hyun-Myung; Kwak, Jae-Hwan; Lee, Heesoon; Suk, Kyoungho; Kim, In-Su; Choi, Dong-Kug

    2016-01-01

    Aim: To investigate the anti-neuroinflammatory activity of a novel synthetic compound, 7-methylchroman-2-carboxylic acid N-(2-trifluoromethyl) phenylamide (MCAP) against LPS-induced microglial activation in vitro. Methods: Primary mouse microglia and BV2 microglia cells were exposed to LPS (50 or 100 ng/mL). The expression of iNOS and COX-2, proinflammatory cytokines, NF-κB and p38 MAPK signaling molecules were analyzed by RT-PCR, Western blot and ELISA. The morphological changes of microglia and nuclear translocation of NF-ĸB were visualized using phase contrast and fluorescence microscopy, respectively. Results: Pretreatment with MCAP (0.1, 1, 10 μmol/L) dose-dependently inhibited LPS-induced expression of iNOS and COX-2 in BV2 microglia cells. Similar results were obtained in primary microglia pretreated with MCAP (0.1, 0.5 μmol/L). MCAP dose-dependently abated LPS-induced release of TNF-α, IL-6 and IL-1β, and mitigated LPS-induced activation of NF-κB by reducing the phosphorylation of IκBα in BV2 microglia cells. Moreover, MCAP attenuated LPS-induced phosphorylation of p38 MAPK, whereas SB203580, a p38 MAPK inhibitor, significantly potentiated MCAP-caused inhibition on the expression of MEF-2 (a transcription factor downstream of p38 MAPK). Conclusion: MCAP exerts anti-inflammatory effects in murine microglia in vitro by inhibiting the p38 MAPK and NF-κB signaling pathways and proinflammatory responses. MCAP may be developed as a novel agent for treating diseases involving activated microglial cells. PMID:26838070

  1. Gallic acid ameliorates renal functions by inhibiting the activation of p38 MAPK in experimentally induced type 2 diabetic rats and cultured rat proximal tubular epithelial cells.

    PubMed

    Ahad, Amjid; Ahsan, Haseeb; Mujeeb, Mohd; Siddiqui, Waseem Ahmad

    2015-10-01

    Diabetic nephropathy (DN) is one of the leading causes of morbidity and mortality in diabetic patients that accounts for about 40% of deaths in type 2 diabetes. p38 mitogen activated protein kinase (p38 MAPK), a serine-threonine kinase, plays an important role in tissue inflammation and is known to be activated under conditions of oxidative stress and hyperglycemia. The role of p38 MAPK has been demonstrated in DN, and its inhibition has been suggested as an alternative approach in the treatment of DN. In the present study, we investigated the nephroprotective effects of an anti-inflammatory phenolic compound, gallic acid (GA, 3,4,5-trihydroxybenzoic acid), in high fat diet/streptozotocin (HFD/STZ) induce type 2 diabetic wistar albino rats. GA (25 mg/kgbw and 50 mg/kgbw, p.o.) treatment for 16 weeks post induction of diabetes led to a significant reduction in the levels of blood glucose, HbA1c, serum creatinine, blood urea nitrogen and proteinuria as well as a significant reduction in the levels of creatinine clearance. GA significantly inhibited the renal p38 MAPK and nuclear factor kappa B (N-κB) activation as well as significantly reduced the levels of renal transforming growth factor beta (TGF-β) and fibronectin. Treatment with GA resulted in a significant reduction in the serum levels of proinflammatory cytokines viz. interleukin 1 beta (IL-1β), IL-6 and tumor necrosis factor alpha (TNF-α). Moreover, GA significantly lowered renal pathology and attenuated renal oxidative stress. In cultured rat NRK 52E proximal tubular epithelial cells, GA treatment inhibited high glucose induced activation of p38 MAPK and NF-κB as well as suppressed proinflammatory cytokine synthesis. The results of the present study provide in vivo and in vitro evidences that the p38 MAPK pathway plays an important role in the pathogenesis of DN, and GA attenuates the p38 MAPK-mediated renal dysfunction in HFD/STZ induced type 2 diabetic rats.

  2. Hyaluronan Oligosaccharides Induce MMP-1 and -3 via Transcriptional Activation of NF-κB and p38 MAPK in Rheumatoid Synovial Fibroblasts

    PubMed Central

    Hanabayashi, Masahiro; Takahashi, Nobunori; Sobue, Yasumori; Hirabara, Shinya; Ishiguro, Naoki; Kojima, Toshihisa

    2016-01-01

    Objective To explore the effect of hyaluronan oligosaccharides (HAoligos) on interactions between HA and its principal receptor, CD44, in rheumatoid synovial fibroblasts (RSFs) and matrix metalloproteinase (MMP) production. Methods RSFs were isolated from rheumatoid synovial tissue. HA distribution was visualized by immunocytochemistry. MMP-1 and MMP-3 induction was analyzed by real-time RT-PCR and immunoblotting. The interaction between HAoligos and their MMP-producing receptors was tested by blocking with anti-CD44 and anti-Toll-like receptor 4 (TLR-4). Phosphorylation of nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) was analyzed by immunoblotting. Results Endogenous HA decreased after treatment with HAoligos, while MMP-1 and MMP-3 expression increased in a dose-dependent manner. Pretreatment with anti-CD44 or anti-TLR-4 antibody significantly reduced the effect of HAoligos on MMP-1 and MMP-3 mRNA expression. NF-κB and p38 MAPK phosphorylation was enhanced by HAoligos pretreated with anti-TLR-4, and HAoligo-induced MMP production was blocked with an inhibitor of NF-κB and p38 MAPK pathways. Conclusions Disruptive changes in CD44-HA interactions by HAoligos enhanced MMP-1 and MMP-3 production via activation of NF-κB and p38 MAPK signaling pathways in RSFs. PMID:27564851

  3. Chlamydial plasmid-encoded protein pORF5 induces production of IL-1β and IL-18 via NALP3 inflammasome activation and p38 MAPK pathway

    PubMed Central

    Cao, Wenjuan; Zou, Yan; Su, Shengmei; He, Zhansheng; Liu, Yan; Huang, Qiulin; Li, Zhongyu

    2015-01-01

    The pathogenesis of Chlamydia-induced inflammation is poorly understood. pORF5 is the only secreted protein encoded by Chlamydial plasmid. This study aims to investigate the effects of pORF5 on the production of interleukin-1β (IL-1β) and interleukin-18 (IL-18) and the underlying mechanisms of these effects. THP-1 (a human acute monocytic leukemia cell line) cells were stimulated by pORF5 with or without pretreatment with Natch domain, Leucine-rich repeat and PYD-containing protein 3 (NALP3) siRNA, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) siRNA, cysteine aspartate-specific protease-1 (caspase-1) specific inhibitor and p38 mitogen-activated protein kinase (p38 MAPK) inhibitor. IL-1β, IL-18 and caspase-1 expression was detected through both ELISA and qRT-PCR. NALP3 and ASC expression was detected by qRT-PCR. The expression of caspase-1 and phosphorylated-p38 MAPK was detected by western blot analysis. pORF5 induced IL-1β, IL-18, caspase-1 and NALP3 inflammasome expression in THP-1 cells. Caspase-1 inhibitor significantly reduced pORF5-induced IL-1β and IL-18 expression. The siRNAs for NALP3 inflammasome significantly reduced pORF5-induced IL-1β, IL-18 and caspase-1 expression. Furthermore, p38 MAPK inhibitor significantly reduced pORF5-induced IL-1β, IL-18, caspase-1 and NALP3 inflammasome expression. pORF5 could induce production of IL-1β and IL-18 via NALP3 inflammasome activation and p38MAPK pathway. pORF5 protein might play an important role in Chlamydia pathogenesis. This study provides a new insight into the molecular pathogenesis of Chlamydial diseases. PMID:26884953

  4. Nanosized titanium dioxide resulted in the activation of TGF-β/Smads/p38MAPK pathway in renal inflammation and fibration of mice.

    PubMed

    Hong, F; Wu, N; Ge, Y; Zhou, Y; Shen, T; Qiang, Q; Zhang, Q; Chen, M; Wang, Y; Wang, L; Hong, J

    2016-06-01

    Titanium dioxide nanoparticles (TiO2 NPs) have been demonstrated to damage the kidneys. However, whether chronic nephritis leads to renal fibration or the fibrosis is associated with the activation of TGF-β/Smads/p38MAPK pathway caused by TiO2 NPs exposure is not well understood. Forty male mice were separately exposed to 0, 2.5, 5, or 10 mg/kg body weight TiO2 NPs for 6 months. Renal biochemical functions and levels of TGF-β/Smads/p38MAPK pathway-related markers and extracellular matrix (ECM) expression in the kidneys were investigated. The findings showed that subchronic TiO2 NPs exposure increased levels of urinary creatisix (Cr), N-acetyl-glucosaminidase, and vanin-1, resulted in severe renal inflammation and fibration. Furthermore, TiO2 NP exposure upregulated expression of transforming growth factor-β1 (TGF-β1, 0.07- to 2.72-fold), Smad2 (0.42- to 1.63-fold), Smad3 (0.02- to 1.94-fold), ECM (0.15- to 2.75-fold), α-smooth muscle actin (0.14- to 3.06-fold), p38 mitogen-activated protein kinase (p38MAPK, 0.11- to 3.78-fold), and nuclear factor-κB (0.4- to 2.27-fold), and downregulated Smad7 (0.05- to 0.61-fold) expression in mouse kidney. Subchronic TiO2 NPs exposure induced changes of renal characteristics towards inflammation and fibration may be mediated via TGF-β/Smads/p38MAPK pathway, and the uses of TiO2 NPs should be carried out cautiously, especially in humans. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1452-1461, 2016.

  5. p38 MAPK in cardioprotection – are we there yet?

    PubMed Central

    Martin, E D; Bassi, R; Marber, M S

    2015-01-01

    PKs transfer a phosphate from ATP to the side-chain hydroxyl group of a serine, threonine or tyrosine residue of a substrate protein. This in turn can alter that protein's function; modulating fundamental cellular processes including, metabolism, transcription, growth, division, differentiation, motility and survival. PKs are subdivided into families based on homology. One such group are the stress-activated kinases, which as the name suggests, are activated in response to cellular stresses such as toxins, cytokines, mechanical deformation and osmotic stress. Members include the p38 MAPK family, which is composed of α, β, γ and δ, isoforms which are encoded by separate genes. These kinases transduce extracellular signals and coordinate the cellular responses needed for adaptation and survival. However, in cardiovascular and other disease states, these same systems can trigger maladaptive responses that aggravate, rather than alleviate, the disease. This situation is analogous to adrenergic, angiotensin and aldosterone signalling in heart failure, where inhibition is beneficial despite the importance of these hormones to homeostasis. The question is whether similar benefits could accrue from p38 inhibition? In this review, we will discuss the structure and function of p38, the history of p38 inhibitors and their use in preclinical studies. Finally, we will summarize the results of recent cardiovascular clinical trials with p38 inhibitors. PMID:25204838

  6. [Studies on cell signaling immunomodulated murine peritoneal suppressor macrophages: LPS and PMA mediate the activation of RAF-1, MAPK p44 and MAPK p42 and p38 MAPK].

    PubMed

    Chang, Z L; Lin, M Q; Wang, M Z; Yao, Z

    1997-03-01

    38 MAPK (mammalian equivalents of HOG1 in yeast) and JNK MAPK have been discovered. The requirement for activation of p38 MAPK for both Thr-180 and Tyr-182 (at TGY motif) has been shown. p38 MAPK is important in certain transcriptional regulatory pathways, since it can phosphorylate the following transcriptional factors: 1) Elk at Ser 383/389 for binding with SRE motif; 2). ATF 2 at Ser 69/71, forming a complex with Myc for DNA binding at CRE motif; 3) Max at Ser-62 to combine DNA of E-Box motif. p38 MAPK can be activated by LPS, inflammatory cytokines, such as TNF and IL-1, osmolarity. To examine the possibility that whether activation of Raf-1 and ERK 1, ERK2 and p38 MAPK can be regulated directly or/and differently by PKC and PKA pathways, herbimycin A (Ki = 0.9 mumol/L), a potent PTK inhibitor (J. Immunol. 155:3944-4003, 1995) at 2 mumol/L concentration was utilized to block Ras/Raf-1/MAPK cascade. After pre-incubation of macrophages with herbimycin A for 30 min or 90 min, cells were treated with LPS (10 micrograms/ml) and PMA (100 nmol/L) for 15 min. No inhibition of phosphorylation of Raf-1, MAPK p44 and MAPK p42 in response to LPS and PMA was observed (Fig. 1 and 3). However, forskolin, a cAMP inducer for protein kinase A (PKA) activation, inhibited the phosphorylation of LPS- and PMA-stimulated Raf-1, MAPK p44 and MAPK p42 (Fig. 2 and 4). Similarly, in agreement with a very recent report from David, M et al in NIH, in which they indicated that forskolin (30 mumol/L) inhibited IFN-beta-stimulated ERK activity by U 266 cells (J. Biol. Chem. 271: 4585-4588 1996), we found that the levels of phosphorylations of Raf-1 and ERK1 and ERK2 were declined when forskolin (30 mumol/L) was added to macrophages for 20 min at 37 degrees C prior to the stimulation by LPS and PMA. Interestingly, under the same condition, forskolin (30 mumol/L) stimulated the phosphorylation of LPS- and PMA-triggered p38 MAPK of murine peritoneal suppressor macrophages, suggesting that

  7. Activation of transient receptor potential vanilloid 4 induces apoptosis in hippocampus through downregulating PI3K/Akt and upregulating p38 MAPK signaling pathways

    PubMed Central

    Jie, P; Hong, Z; Tian, Y; Li, Y; Lin, L; Zhou, L; Du, Y; Chen, L; Chen, L

    2015-01-01

    Transient receptor potential vanilloid 4 (TRPV4) is a calcium-permeable cation channel that is sensitive to cell swelling, arachidonic acid and its metabolites, epoxyeicosatrienoic acids, which are associated with cerebral ischemia. The activation of TRPV4 induces cytotoxicity in many types of cells, accompanied by an increase in the intracellular free calcium concentration. TRPV4 activation modulates the mitogen-activated protein kinase (MAPK) and phosphatidyl inositol 3 kinase (PI3K)/ protein kinase B (Akt) signaling pathways that regulate cell death and survival. Herein, we examined TRPV4-induced neuronal apoptosis by intracerebroventricular (ICV) injection of a TRPV4 agonist (GSK1016790A) and assessed its involvement in cerebral ischemic injury. ICV injection of GSK1016790A dose-dependently induced apoptosis in the mouse hippocampi (GSK-injected mice). The protein level of phosphorylated p38 MAPK (p-p38 MAPK) was markedly increased and that of phosphorylated c-Jun N-terminal protein kinase (p-JNK) was virtually unchanged. TRPV4 activation also decreased Bcl-2/Bax protein ratio and increased the cleaved caspase-3 protein level, and these effects were blocked by a PI3K agonist and a p38 MAPK antagonist, but were unaffected by a JNK antagonist. ICV injection of the TRPV4 antagonist HC-067047 reduced brain infarction after reperfusion for 48 h in mice with middle cerebral artery occlusion (MCAO). In addition, HC-067047 treatment attenuated the decrease in the phosphorylated Akt protein level and the increase in p-p38 MAPK protein level at 48 h after MCAO, while the increase in p-JNK protein level remained unchanged. Finally, the decreased Bcl-2/Bax protein ratio and the increased cleaved caspase-3 protein level at 48 h after MCAO were markedly attenuated by HC-067047. We conclude that activation of TRPV4 induces apoptosis by downregulating PI3K/Akt and upregulating p38 MAPK signaling pathways, which is involved in cerebral ischemic injury. PMID:26043075

  8. Baicalin Attenuates Hypoxia-Induced Pulmonary Arterial Hypertension to Improve Hypoxic Cor Pulmonale by Reducing the Activity of the p38 MAPK Signaling Pathway and MMP-9.

    PubMed

    Yan, Shuangquan; Wang, Yiran; Liu, Panpan; Chen, Ali; Chen, Mayun; Yao, Dan; Xu, Xiaomei; Wang, Liangxing; Huang, Xiaoying

    2016-01-01

    Baicalin has a protective effect on hypoxia-induced pulmonary hypertension in rats, but the mechanism of this effect remains unclear. Thus, investigating the potential mechanism of this effect was the aim of the present study. Model rats that display hypoxic pulmonary hypertension and cor pulmonale under control conditions were successfully generated. We measured a series of indicators to observe the levels of pulmonary arterial hypertension, pulmonary arteriole remodeling, and right ventricular remodeling. We assessed the activation of p38 mitogen-activated protein kinase (MAPK) in the pulmonary arteriole walls and pulmonary tissue homogenates using immunohistochemistry and western blot analyses, respectively. The matrix metalloproteinase- (MMP-) 9 protein and mRNA levels in the pulmonary arteriole walls were measured using immunohistochemistry and in situ hybridization. Our results demonstrated that baicalin not only reduced p38 MAPK activation in both the pulmonary arteriole walls and tissue homogenates but also downregulated the protein and mRNA expression levels of MMP-9 in the pulmonary arteriole walls. This downregulation was accompanied by the attenuation of pulmonary hypertension, arteriole remodeling, and right ventricular remodeling. These results suggest that baicalin may attenuate pulmonary hypertension and cor pulmonale, which are induced by chronic hypoxia, by downregulating the p38 MAPK/MMP-9 pathway. PMID:27688788

  9. Baicalin Attenuates Hypoxia-Induced Pulmonary Arterial Hypertension to Improve Hypoxic Cor Pulmonale by Reducing the Activity of the p38 MAPK Signaling Pathway and MMP-9

    PubMed Central

    Wang, Yiran; Chen, Ali; Chen, Mayun; Yao, Dan; Xu, Xiaomei; Wang, Liangxing

    2016-01-01

    Baicalin has a protective effect on hypoxia-induced pulmonary hypertension in rats, but the mechanism of this effect remains unclear. Thus, investigating the potential mechanism of this effect was the aim of the present study. Model rats that display hypoxic pulmonary hypertension and cor pulmonale under control conditions were successfully generated. We measured a series of indicators to observe the levels of pulmonary arterial hypertension, pulmonary arteriole remodeling, and right ventricular remodeling. We assessed the activation of p38 mitogen-activated protein kinase (MAPK) in the pulmonary arteriole walls and pulmonary tissue homogenates using immunohistochemistry and western blot analyses, respectively. The matrix metalloproteinase- (MMP-) 9 protein and mRNA levels in the pulmonary arteriole walls were measured using immunohistochemistry and in situ hybridization. Our results demonstrated that baicalin not only reduced p38 MAPK activation in both the pulmonary arteriole walls and tissue homogenates but also downregulated the protein and mRNA expression levels of MMP-9 in the pulmonary arteriole walls. This downregulation was accompanied by the attenuation of pulmonary hypertension, arteriole remodeling, and right ventricular remodeling. These results suggest that baicalin may attenuate pulmonary hypertension and cor pulmonale, which are induced by chronic hypoxia, by downregulating the p38 MAPK/MMP-9 pathway. PMID:27688788

  10. Baicalin Attenuates Hypoxia-Induced Pulmonary Arterial Hypertension to Improve Hypoxic Cor Pulmonale by Reducing the Activity of the p38 MAPK Signaling Pathway and MMP-9

    PubMed Central

    Wang, Yiran; Chen, Ali; Chen, Mayun; Yao, Dan; Xu, Xiaomei; Wang, Liangxing

    2016-01-01

    Baicalin has a protective effect on hypoxia-induced pulmonary hypertension in rats, but the mechanism of this effect remains unclear. Thus, investigating the potential mechanism of this effect was the aim of the present study. Model rats that display hypoxic pulmonary hypertension and cor pulmonale under control conditions were successfully generated. We measured a series of indicators to observe the levels of pulmonary arterial hypertension, pulmonary arteriole remodeling, and right ventricular remodeling. We assessed the activation of p38 mitogen-activated protein kinase (MAPK) in the pulmonary arteriole walls and pulmonary tissue homogenates using immunohistochemistry and western blot analyses, respectively. The matrix metalloproteinase- (MMP-) 9 protein and mRNA levels in the pulmonary arteriole walls were measured using immunohistochemistry and in situ hybridization. Our results demonstrated that baicalin not only reduced p38 MAPK activation in both the pulmonary arteriole walls and tissue homogenates but also downregulated the protein and mRNA expression levels of MMP-9 in the pulmonary arteriole walls. This downregulation was accompanied by the attenuation of pulmonary hypertension, arteriole remodeling, and right ventricular remodeling. These results suggest that baicalin may attenuate pulmonary hypertension and cor pulmonale, which are induced by chronic hypoxia, by downregulating the p38 MAPK/MMP-9 pathway.

  11. Isoliensinine induces apoptosis in triple-negative human breast cancer cells through ROS generation and p38 MAPK/JNK activation

    PubMed Central

    Zhang, Xiyu; Wang, Xiyao; Wu, Tingting; Li, Boxuan; Liu, Tianqi; Wang, Rong; Liu, Qiao; Liu, Zhaojian; Gong, Yaoqin; Shao, Changshun

    2015-01-01

    Isoliensinine, liensinine and neferine are major bisbenzylisoquinoline alkaloids in the seed embryo of lotus (Nelumbo nucifera), and exhibit potential anti-cancer activity. Here, we explored the effects of these alkaloids on triple-negative breast cancer cells and found that among the three alkaloids isoliensinine possesses the most potent cytotoxic effect, primarily by inducing apoptosis. Interestingly, isoliensinine showed a much lower cytotoxicity against MCF-10A, a normal human breast epithelial cell line. Further studies showed that isoliensinine could significantly increase the production of reactive oxygen species (ROS) in triple-negative breast cancer cells, but not in MCF-10A cells. The isoliensinine-induced apoptosis could be attenuated by radical oxygen scavenger N-acetyl cysteine, suggesting that the cytotoxic effect of isoliensinine on cancer cells is at least partially achieved by inducing oxidative stress. We found that both p38 MAPK and JNK signaling pathways were activated by isoliensinine treatment and contributed to the induction of apoptosis. Furthermore, inhibitors or specific siRNAs of p38 MAPK and JNK could attenuate apoptosis induced by isoliensinine. However, only the p38 inhibitor or p38-specific siRNA blocked the elevation of ROS in isoliensinine-treated cells. Our findings thus revealed a novel antitumor effect of isoliensinine on breast cancer cells and may have therapeutic implications. PMID:26219228

  12. Isoliensinine induces apoptosis in triple-negative human breast cancer cells through ROS generation and p38 MAPK/JNK activation.

    PubMed

    Zhang, Xiyu; Wang, Xiyao; Wu, Tingting; Li, Boxuan; Liu, Tianqi; Wang, Rong; Liu, Qiao; Liu, Zhaojian; Gong, Yaoqin; Shao, Changshun

    2015-01-01

    Isoliensinine, liensinine and neferine are major bisbenzylisoquinoline alkaloids in the seed embryo of lotus (Nelumbo nucifera), and exhibit potential anti-cancer activity. Here, we explored the effects of these alkaloids on triple-negative breast cancer cells and found that among the three alkaloids isoliensinine possesses the most potent cytotoxic effect, primarily by inducing apoptosis. Interestingly, isoliensinine showed a much lower cytotoxicity against MCF-10A, a normal human breast epithelial cell line. Further studies showed that isoliensinine could significantly increase the production of reactive oxygen species (ROS) in triple-negative breast cancer cells, but not in MCF-10A cells. The isoliensinine-induced apoptosis could be attenuated by radical oxygen scavenger N-acetyl cysteine, suggesting that the cytotoxic effect of isoliensinine on cancer cells is at least partially achieved by inducing oxidative stress. We found that both p38 MAPK and JNK signaling pathways were activated by isoliensinine treatment and contributed to the induction of apoptosis. Furthermore, inhibitors or specific siRNAs of p38 MAPK and JNK could attenuate apoptosis induced by isoliensinine. However, only the p38 inhibitor or p38-specific siRNA blocked the elevation of ROS in isoliensinine-treated cells. Our findings thus revealed a novel antitumor effect of isoliensinine on breast cancer cells and may have therapeutic implications. PMID:26219228

  13. p38MAPK activation is involved in androgen-independent proliferation of human prostate cancer cells by regulating IL-6 secretion

    SciTech Connect

    Shida, Yohei; Igawa, Tsukasa . E-mail: tigawa@net.nagasaki-u.ac.jp; Hakariya, Tomoaki; Sakai, Hideki; Kanetake, Hiroshi

    2007-02-16

    Increased levels of serum interleukin-6 (IL-6) are frequently observed in patients with advanced, hormone-refractory prostate cancer. However, the precise mechanism of IL-6 regulation is still largely unknown. Since prostate cancer gradually progresses to an androgen-independent state despite the stress caused by various therapeutic agents, we hypothesized the stress-activated protein kinases (SAPKs) involvement in androgen-independent growth or IL-6 secretion of prostate cancer cells. Using PC-3 and DU145 human prostate cancer cells, we analyzed the role of SAPKs in IL-6 mediated cell growth and found that the p38MAPK and JNK are involved in androgen-independent cancer cell growth. Furthermore, IL-6 secretion by PC-3 and DU145 cells was significantly suppressed by SAPKs inhibitor, especially by p38MAPK inhibitor SB203580, but not by JNK inhibitor SP600125 nor by MEK inhibitor, PD98059. These results raised the possibility that the IL-6 mediated androgen-independent proliferation of PC-3 and DU145 cells is regulated at least partly via SAPKs signaling pathway especially through p38MAPK activation.

  14. Isomenthone protects human dermal fibroblasts from TNF-α-induced death possibly by preventing activation of JNK and p38 MAPK.

    PubMed

    Jung, Eunsun; Byun, Sangyo; Kim, Seungbeom; Kim, Moohan; Park, Deokhoon; Lee, Jongsung

    2012-10-01

    Cell death evoked by tumor necrosis factor-α (TNF-α) is regulated by the TNF-α receptor-associated death domain containing protein, which interacts with and activates apoptotic proteases triggering cell death. c-Jun N-terminal kinase (JNK) and p38 MAPK, induce the apoptotic program and are indispensible early elements in stress-induced apoptosis that control the release of cytochrome c. Isomenthone is a constituent of the essential oil of Mentha arvensis L. and is used as a fragrance and flavor in the cosmetic, drug, and food industries. In this study, we investigated the protective effects of isomenthone against TNF-α-induced cell death and its mechanism in human dermal fibroblasts. To understand the cytoprotective role of isomenthone, MTT and terminal deoxynucleotidyl transferase dUTP nick end labeling assays for cell viability and enzyme-linked immunosorbent assay analysis for the mechanistic study were performed. We found that isomenthone inhibited the TNF-α-mediated reduction in cell viability and inhibited the increase in apoptosis under a serum-free condition. Isomenthone also blocked the JNK and p38 MAPK pathways and downstream apoptotic events. These results indicate that isomenthone has the potential to protect fibroblasts against TNF-α-induced cell death under a serum-deprived condition by blocking activation of the JNK and p38 MAPK pathways and downstream apoptotic events.

  15. 6-Hydroxydopamine activates the mitochondrial apoptosis pathway through p38 MAPK-mediated, p53-independent activation of Bax and PUMA.

    PubMed

    Gomez-Lazaro, Maria; Galindo, Maria F; Concannon, Caoimhín G; Segura, Miguel F; Fernandez-Gomez, Francisco J; Llecha, Nuria; Comella, Joan X; Prehn, Jochen H M; Jordan, Joaquin

    2008-03-01

    Mitochondrial alterations have been associated with the cytotoxic effect of 6-hydroxydopamine (6-OHDA), a widely used toxin to study Parkinson's disease. In previous work, we have demonstrated that 6-OHDA increases mitochondrial membrane permeability leading to cytochrome c release, but the precise mechanisms involved in this process remain unknown. Herein we studied the mechanism of increased mitochondrial permeability of SH-SY5Y neuroblastoma cells in response to 6-OHDA. Cytochrome c release induced by 6-OHDA occurred, in both SH-SY5Y cells and primary cultures, in the absence of mitochondrial swelling or a decrease in mitochondrial calcein fluorescence, suggesting little involvement of the mitochondrial permeability transition pore in this process. In contrast, 6-OHDA-induced cell death was associated with a significant translocation of the pro-apoptotic Bax protein from the cytosol to mitochondria and with a significant induction of the BH3-only protein PUMA. Experiments in mouse embryonic fibroblasts deficient in Bax or PUMA demonstrated a role for both proteins in 6-OHDA-induced apoptosis. Although 6-OHDA elevated both total and nuclear p53 protein levels, activation of p53 was not essential for subsequent cell death. In contrast, we found that p38 mitogen-activated protein kinase (MAPK) was activated early during 6-OHDA-induced apoptosis, and that treatment with the p38 MAPK inhibitor SKF86002 potently inhibited PUMA induction, green fluorescent protein-Bax redistribution and apoptosis in response to 6-OHDA. These data demonstrate a critical involvement of p38 MAPK, PUMA, and Bax in 6-OHDA-induced apoptosis.

  16. Stress-induced interaction between p38 MAPK and HSP70

    SciTech Connect

    Gong, Xiaowei; Luo, Tingting; Deng, Peng; Liu, Zhenxi; Xiu, Jiancheng; Shi, Hongqin; Jiang, Yong

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer HSP70 interacts to p38 MAPK in vitro and in vivo. Black-Right-Pointing-Pointer HSP70 co-localizes with p38 MAPK in the nucleus upon stress. Black-Right-Pointing-Pointer HSP70 is involved in the nuclear phosphorylation of MK2 by p38 MAPK. -- Abstract: p38 MAPK, one of the four MAPK subfamilies in mammalian cells, is activated by environmental stresses and pro-inflammatory cytokines, playing fundamental roles in many biological processes. Despite all that is known on the structure and functions of p38, many questions still exist. The coupling of activation and nuclear translocation represents an important aspect of p38 signaling. In our effort in exploring the potential chaperone for p38 translocation, we performed an endogenous pull-down assay and identified HSP70 as a potential interacting protein of p38. We confirmed the interaction between p38 and HSP70 in vitro and in vivo, and identified their interaction domains. We also showed stress-induced nuclear co-localization of these two proteins. Our preliminary result indicated that HSP70 was related to the phosphorylation of MK2, a specific nuclear downstream target of p38, suggesting HSP70 is a potential chaperone for the nuclear translocation of p38.

  17. Role of TLR4/NADPH oxidase/ROS-activated p38 MAPK in VCAM-1 expression induced by lipopolysaccharide in human renal mesangial cells

    PubMed Central

    2012-01-01

    Background In bacteria-induced glomerulonephritis, Toll-like receptor 4 (TLR4) activation by lipopolysaccharide (LPS, a key component of the outer membranes of Gram-negative bacteria) can increase oxidative stress and the expression of vascular cell adhesion molecule-1 (VCAM-1), which recruits leukocytes to the glomerular mesangium. However, the mechanisms underlying VCAM-1 expression induced by LPS are still unclear in human renal mesangial cells (HRMCs). Results We demonstrated that LPS induced VCAM-1 mRNA and protein levels associated with an increase in the promoter activity of VCAM-1, determined by Western blot, RT-PCR, and promoter assay. LPS-induced responses were inhibited by transfection with siRNAs of TLR4, myeloid differentiation factor 88 (MyD88), Nox2, Nox4, p47phox, c-Src, p38 MAPK, activating transcription factor 2 (ATF2), and p300 or pretreatment with the inhibitors of reactive oxygen species (ROS, edaravone), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)], c-Src (PP1), p38 MAPK (SB202190), and p300 (GR343). LPS induced NADPH oxidase activation, ROS production, and p47phox translocation from the cytosol to the membrane, which were reduced by PP1 or c-Src siRNA. We observed that LPS induced TLR4, MyD88, c-Src, and p47phox complex formation determined by co-immunoprecipitation and Western blot. We further demonstrated that LPS stimulated ATF2 and p300 phosphorylation and complex formation via a c-Src/NADPH oxidase/ROS/p38 MAPK pathway. Up-regulation of VCAM-1 led to enhancing monocyte adhesion to HRMCs challenged with LPS, which was inhibited by siRNAs of c-Src, p47phox, p38 MAPK, ATF2, and p300 or pretreatment with an anti-VCAM-1 neutralizing antibody. Conclusions In HRMCs, LPS-induced VCAM-1 expression was, at least in part, mediated through a TLR4/MyD88/ c-Src/NADPH oxidase/ROS/p38 MAPK-dependent p300 and ATF2 pathway associated with recruitment of monocyte adhesion to kidney. Blockade of these pathways may reduce monocyte

  18. Angiotensin II-induced pro-fibrotic effects require p38MAPK activity and transforming growth factor beta 1 expression in skeletal muscle cells.

    PubMed

    Morales, María Gabriela; Vazquez, Yaneisi; Acuña, María José; Rivera, Juan Carlos; Simon, Felipe; Salas, José Diego; Alvarez Ruf, Joel; Brandan, Enrique; Cabello-Verrugio, Claudio

    2012-11-01

    Fibrotic disorders are typically characterised by excessive connective tissue and extracellular matrix (ECM) deposition that preclude the normal healing of different tissues. Several skeletal muscle dystrophies are characterised by extensive fibrosis. Among the factors involved in skeletal muscle fibrosis is angiotensin II (Ang-II), a key protein of the renin-angiotensin system (RAS). We previously demonstrated that myoblasts responded to Ang-II by increasing the ECM protein levels mediated by AT-1 receptors, implicating an Ang-II-induced reactive oxygen species (ROS) by a NAD(P)H oxidase-dependent mechanism. In this paper, we show that in myoblasts, Ang-II induced the increase of transforming growth factor beta 1 (TGF-β1) and connective tissue growth factor (CTGF) expression through its AT-1 receptor. This effect is dependent of the NAD(P)H oxidase (NOX)-induced ROS, as indicated by a decrease of the expression of both pro-fibrotic factors when the ROS production was inhibited via the NOX inhibitor apocynin. The increase in pro-fibrotic factors levels was paralleled by enhanced p38MAPK and ERK1/2 phosphorylation in response to Ang-II. However, only the p38MAPK activity was critical for the Ang-II-induced fibrotic effects, as indicated by the decrease in the Ang-II-induced TGF-β1 and CTGF expression and fibronectin levels by SB-203580, an inhibitor of the p38MAPK, but not by U0126, an inhibitor of ERK1/2 phosphorylation. Furthermore, we showed that the Ang-II-dependent p38MAPK activation, but not the ERK1/2 phosphorylation, was necessary for the NOX-derived ROS. In addition, we demonstrated that TGF-β1 expression was required for the Ang-II-induced pro-fibrotic effects evaluated by using SB-431542, an inhibitor of TGF-βRI kinase activity, and by knocking down TGF-β1 levels by shRNA technique. These results strongly suggest that the fibrotic response to Ang-II is mediated by the AT-1 receptor and requires the p38MAPK phosphorylation, NOX-induced ROS, and TGF

  19. Paeonol suppresses oxidized low-density lipoprotein induced endothelial cell apoptosis via activation of LOX-1/p38MAPK/NF-κB pathway.

    PubMed

    Bao, Mei-Hua; Zhang, Yi-Wen; Zhou, Hong-Hao

    2013-03-27

    Paeonol is an active compound isolated from traditional Chinese medicine, and has been shown to have anti-atherosclerosis, anti-inflammatory, antioxidant effects. The present investigation was undertaken to determine the suppression effects of paeonol on oxidized low-density lipoprotein (ox-LDL) induced endothelial cell line HUVEC apoptosis and to uncover some of the underlying mechanisms of these effects. Cell viability and lactate dehydrogenase (LDH) were measured to evaluate the cell injuries. Apoptosis was evaluated by Hoechst 33342 staining and flow cytometry. Intracellular reactive oxygen species (ROS) generation was detected by 2',7'-dichlorofluorescein diacetate (DCFH-DA). Real-time PCR was used to confirm the expression of LOX-1 mRNA. Western blotting was used to evaluate the protein expression of LOX-1 and Bcl-2, as well as caspase-3 cleavage, p38-mitogen-activated protein kinase (p38MAPK) phosphorylation. NF-κB nuclear translocation was detected by Western blotting and immunofluorescence. Caspase-3 activity was measured using a colorimetric protease assay kit. The results showed that ox-LDL significantly decreased cell viability and increased the LDH release, as well as the apoptotic rate (P<0.01). Pre-treatment of paeonol resulted in remarkable increase of cell viability, decrease of LDH release and cell apoptosis in a concentration-dependent manner. Besides, ox-LDL caused the up-regulation of LOX-1, the down-regulation of Bcl-2, the phosphorylation of p38MAPK, the translocation of NF-κB and the activation of caspase-3. Paeonol pre-treatment reversed these effects introduced by ox-LDL. Moreover, paeonol also showed its inhibition effects on ox-LDL induced ROS overproduction. These results indicate the preventive effects of paeonol on ox-LDL induced endothelial cell apoptosis. The effects might, at least partly, be obtained via inhibition of LOX-1-ROS- p38MAPK-NF-κB signaling pathway.

  20. The CORM ALF-186 Mediates Anti-Apoptotic Signaling via an Activation of the p38 MAPK after Ischemia and Reperfusion Injury in Retinal Ganglion Cells

    PubMed Central

    Ulbrich, Felix; Kaufmann, Kai B.; Meske, Alexander; Lagrèze, Wolf A.; Augustynik, Michael; Buerkle, Hartmut; Ramao, Carlos C.; Biermann, Julia

    2016-01-01

    Purpose Ischemia and reperfusion injury may induce apoptosis and lead to sustained tissue damage and loss of function, especially in neuronal organs. While carbon monoxide is known to exert protective effects after various harmful events, the mechanism of carbon monoxide releasing molecules in neuronal tissue has not been investigated yet. We hypothesize that the carbon monoxide releasing molecule (CORM) ALF-186, administered after neuronal ischemia-reperfusion injury (IRI), counteracts retinal apoptosis and its involved signaling pathways and consecutively reduces neuronal tissue damage. Methods IRI was performed in rat´s retinae for 1 hour. The water-soluble CORM ALF-186 (10 mg/kg) was administered intravenously via a tail vein after reperfusion. After 24 and 48 hours, retinal tissue was harvested to analyze mRNA and protein expression of Bcl-2, Bax, Caspase-3, ERK1/2, p38 and JNK. Densities of fluorogold pre-labeled retinal ganglion cells (RGC) were analyzed 7 days after IRI. Immunohistochemistry was performed on retinal cross sections. Results ALF-186 significantly reduced IRI mediated loss of RGC. ALF-186 treatment differentially affected mitogen-activated protein kinases (MAPK) phosphorylation: ALF-186 activated p38 and suppressed ERK1/2 phosphorylation, while JNK remained unchanged. Furthermore, ALF-186 treatment affected mitochondrial apoptosis, decreasing pro-apoptotic Bax and Caspase-3-cleavage, but increasing anti-apoptotic Bcl-2. Inhibition of p38-MAPK using SB203580 reduced ALF-186 mediated anti-apoptotic effects. Conclusion In this study, ALF-186 mediated substantial neuroprotection, affecting intracellular apoptotic signaling, mainly via MAPK p38. CORMs may thus represent a promising therapeutic alternative treating neuronal IRI. PMID:27764224

  1. 4-Hydroxynonenal enhances MMP-9 production in murine macrophages via 5-lipoxygenase-mediated activation of ERK and p38 MAPK

    SciTech Connect

    Lee, Seung J.; Kim, Chae E.; Yun, Mi R.; Seo, Kyo W.; Park, Hye M.; Yun, Jung W.; Shin, Hwa K.; Bae, Sun S.; Kim, Chi D.

    2010-01-15

    Exaggerated levels of 4-hydroxynonenal (HNE) and 5-lipoxygenase (5-LO) co-exist in macrophages in atherosclerotic lesions, and activated macrophages produce MMP-9 that degrades atherosclerotic plaque constituents. This study investigated the effects of HNE on MMP-9 production, and the potential role for 5-LO derivatives in MMP-9 production in murine macrophages. Stimulation of J774A.1 cells with HNE led to activation of 5-LO, as measured by leukotriene B{sub 4} (LTB{sub 4}) production. This was associated with an increased production of MMP-9, which was blunted by inhibition of 5-LO with MK886, a 5-LO inhibitor or with 5-LO siRNA. A cysteinyl-LT{sub 1} (cysLT{sub 1}) receptor antagonist, REV-5901 as well as a BLT{sub 1} receptor antagonist, U-75302, also attenuated MMP-9 production induced by HNE. Furthermore, LTB{sub 4} and cysLT (LTC{sub 4} and LTD{sub 4}) enhanced MMP-9 production in macrophages, suggesting a pivotal role for 5-LO in HNE-mediated production of MMP-9. Among the MAPK pathways, LTB{sub 4} and cysLT enhanced phosphorylation of ERK and p38 MAPK, but not JNK. Linked to these results, a p38 MAPK inhibitor as well as an ERK inhibitor blunted MMP-9 production induced by LT. Collectively, these data suggest that 5-LO-derived LT mediates HNE-induced MMP-9 production via activation of ERK and p38 MAPK pathways, consequently leading to plaque instability in atherosclerosis.

  2. Critical role of the transient activation of p38 MAPK in the etiology of skeletal muscle insulin resistance induced by low-level in vitro oxidant stress

    PubMed Central

    Diamond-Stanic, Maggie K.; Marchionne, Elizabeth M.; Teachey, Mary K.; Durazo, David E.; Kim, John S.; Henriksen, Erik J.

    2011-01-01

    Increased cellular exposure to oxidants may contribute to the development of insulin resistance and type 2 diabetes. Skeletal muscle is the primary site of insulin-dependent glucose disposal in the body; however, the effects of oxidative stress on insulin signaling and glucose transport activity in mammalian skeletal muscle are not well understood. We therefore studied the effects of a low-level in vitro oxidant stress (30–40 μM H2O2) on basal and insulin-stimulated (5 mU/ml) glucose transport activity and insulin signaling at 2, 4, and 6 hr in isolated rat soleus muscle. H2O2 increased basal glucose transport activity at 2 and 4 hr, but not at 6 hr. This lowlevel oxidant stress significantly impaired insulin-stimulated glucose transport activity at all time points, and was associated with inhibition of insulin-stimulated phosphorylation of Akt Ser473 and GSK-3β Ser9. In the presence of insulin, H2O2 decreased total protein expression of IRS-1 at 6 hr and IRS-2 at 4 and 6 hr. Phosphorylation of p38 MAPK Thr180/Tyr182 was transiently increased by H2O2 in the presence and absence of insulin at 2 and 4 hr, but not at 6 hr. Selective inhibition of p38 MAPK with A304000 partially rescued the H2O2-induced reduction in insulin-stimulated glucose transport activity. These results indicate that direct in vitro exposure of isolated mammalian skeletal muscle to a low-level oxidant stress impairs distal insulin signaling and insulin-stimulated glucose transport activity, at least in part, due to a p38 MAPK-dependent mechanism. PMID:21241662

  3. Attenuated Leishmania induce pro-inflammatory mediators and influence leishmanicidal activity by p38 MAPK dependent phagosome maturation in Leishmania donovani co-infected macrophages.

    PubMed

    Banerjee, Somenath; Bose, Dipayan; Chatterjee, Nabanita; Das, Subhadip; Chakraborty, Sreeparna; Das, Tanya; Saha, Krishna Das

    2016-01-01

    Promastigote form of Leishmania, an intracellular pathogen, delays phagosome maturation and resides inside macrophages. But till date limited study has been done to manipulate the phagosomal machinery of macrophages to restrict Leishmania growth. Attenuated Leishmania strain exposed RAW 264.7 cells showed a respiratory burst and enhanced production of pro-inflammatory mediators. The augmentation of pro-inflammatory activity is mostly attributed to p38 MAPK and p44/42 MAPK. In our study, these activated macrophages are found to induce phagosome maturation when infected with pathogenic Leishmania donovani. Increased co-localization of carboxyfluorescein succinimidyl ester labeled pathogenic L. donovani with Lysosome was found. Moreover, increased co-localization was observed between pathogenic L. donovani and late phagosomal markers viz. Rab7, Lysosomal Associated Membrane Protein 1, Cathepsin D, Rab9, and V-ATPase which indicate phagosome maturation. It was also observed that inhibition of V-type ATPase caused significant hindrance in attenuated Leishmania induced phagosome maturation. Finally, it was confirmed that p38 MAPK is the key player in acidification and maturation of phagosome in attenuated Leishmania strain pre-exposed macrophages. To our knowledge, this study for the first time reported an approach to induce phagosome maturation in L. donovani infected macrophages which could potentiate short-term prophylactic response in future. PMID:26928472

  4. Attenuated Leishmania induce pro-inflammatory mediators and influence leishmanicidal activity by p38 MAPK dependent phagosome maturation in Leishmania donovani co-infected macrophages

    PubMed Central

    Banerjee, Somenath; Bose, Dipayan; Chatterjee, Nabanita; Das, Subhadip; Chakraborty, Sreeparna; Das, Tanya; Saha, Krishna Das

    2016-01-01

    Promastigote form of Leishmania, an intracellular pathogen, delays phagosome maturation and resides inside macrophages. But till date limited study has been done to manipulate the phagosomal machinery of macrophages to restrict Leishmania growth. Attenuated Leishmania strain exposed RAW 264.7 cells showed a respiratory burst and enhanced production of pro-inflammatory mediators. The augmentation of pro-inflammatory activity is mostly attributed to p38 MAPK and p44/42 MAPK. In our study, these activated macrophages are found to induce phagosome maturation when infected with pathogenic Leishmania donovani. Increased co-localization of carboxyfluorescein succinimidyl ester labeled pathogenic L. donovani with Lysosome was found. Moreover, increased co-localization was observed between pathogenic L. donovani and late phagosomal markers viz. Rab7, Lysosomal Associated Membrane Protein 1, Cathepsin D, Rab9, and V-ATPase which indicate phagosome maturation. It was also observed that inhibition of V-type ATPase caused significant hindrance in attenuated Leishmania induced phagosome maturation. Finally, it was confirmed that p38 MAPK is the key player in acidification and maturation of phagosome in attenuated Leishmania strain pre-exposed macrophages. To our knowledge, this study for the first time reported an approach to induce phagosome maturation in L. donovani infected macrophages which could potentiate short-term prophylactic response in future. PMID:26928472

  5. p38 MAPK regulates steroidogenesis through transcriptional repression of STAR gene.

    PubMed

    Zaidi, Syed Kashif; Shen, Wen-Jun; Bittner, Stefanie; Bittner, Alex; McLean, Mark P; Han, Jiahuai; Davis, Roger J; Kraemer, Fredric B; Azhar, Salman

    2014-08-01

    STAR/StarD1, part of a protein complex, mediates the transport of cholesterol from the outer to inner mitochondrial membrane, which is the rate-limiting step for steroidogenesis, and where steroid hormone synthesis begins. Herein, we examined the role of oxidant-sensitive p38 MAPKs in the regulation of STAR gene transcription, using model steroidogenic cell lines. Our data indicate that oxidant activation of p38 MAPK exhibits a negative regulatory role in the induction of functional expression of STAR, as evidenced by enhanced induction of STAR (mRNA/protein) expression and increased steroidogenesis during pharmacological inhibition of p38 MAPK or in cells with increased transient overexpression of a dominant-negative (dn) form of p38 MAPKα or p38 MAPKβ. Studies with rat Star-promoter demonstrated that overexpression of p38 MAPKα-wt, -β, or -γ significantly reduced both basal and cAMP-sensitive promoter activity. In contrast, overexpression of p38 MAPKα-dn, -β, or -γ enhanced the Star promoter activity under basal conditions and in response to cAMP stimulation. Use of various constitutively active and dn constructs and designer knock-out cell lines demonstrated that MKK3 and MKK6, the upstream activators of p38 MAPKs, play a role in p38 MAPKα-mediated inhibition of Star promoter activity. In addition, our studies raised the possibility of CREB being a potential target of the p38 MAPK inhibitory effect on Star promoter activity. Collectively, these data provide novel mechanistic information about how oxidant-sensitive p38 MAPKs, particularly p38 MAPKα, contribute to the negative regulation of Star gene expression and inhibit steroidogenesis.

  6. Combined Effects of Cadmium and UVB Radiation on Sea Urchin Embryos: Skeleton Impairment Parallels p38 MAPK Activation and Stress Genes Overexpression.

    PubMed

    Bonaventura, Rosa; Russo, Roberta; Zito, Francesca; Matranga, Valeria

    2015-05-18

    Human and natural activities release many pollutants in the marine environment. The mixture of pollutants can affect many organisms concurrently. We used Paracentrotus lividus as a model to analyze the effects on signal transduction pathways and stress gene expression in embryos exposed continuously to double stress, i.e., cadmium (Cd) from fertilization and UVB at cleavage (Cd/UVB-embryos). By microscopical inspection, we evaluated embryonic morphology after 72 h of development. Tissue-specific markers were used to assess mesoderm differentiation by immunofluorescence. We analyzed p38MAPK, ERK1/2, and JNK activation by Western blot and mRNA profiles of Pl-MT, Pl-14-3-3epsilon, and Pl-jun genes by real-time quantitative polymerase chain reaction (qPCR) and the localization of their transcripts by whole mount in situ hybridization (WMISH). We found that the Cd/UVB combined exposure induced morphological malformations in 76% of pluteus embryos, mainly affecting the development of the skeleton, including the normal branching of skeletal roads. In Cd/UVB-embryos, p38MAPK was activated 1 h after UVB exposure and a remarkable overexpression of the Pl-MT, Pl-14.3.3epsilon, and Pl-jun genes 24 h after UVB exposure. Pl-MT and Pl-14.3.3epsilon mRNAs were misexpressed as they were localized in a position different from that observed in wild-type embryos, i.e., the intestine. On the contrary, Pl-jun mRNA has remained localized in the skeletogenic cells despite their displacement in exposed embryos. In conclusion, Cd/UVB exposure affected skeletal patterning producing alternative morphologies in which p38MAPK activation and Pl-MT, Pl-14.3.3epsilon, and Pl-jun gene overexpression seem linked to a protective role against the stress response induced by Cd/UVB.

  7. Distal retinal ganglion cell axon transport loss and activation of p38 MAPK stress pathway following VEGF-A antagonism

    PubMed Central

    Foxton, R; Osborne, A; Martin, K R; Ng, Y-S; Shima, D T

    2016-01-01

    There is increasing evidence that VEGF-A antagonists may be detrimental to neuronal health following ocular administration. Here we investigated firstly the effects of VEGF-A neutralization on retinal neuronal survival in the Ins2Akita diabetic and JR5558 spontaneous choroidal neovascularization (CNV) mice, and then looked at potential mechanisms contributing to cell death. We detected elevated apoptosis in the ganglion cell layer in both these models following VEGF-A antagonism, indicating that even when vascular pathologies respond to treatment, neurons are still vulnerable to reduced VEGF-A levels. We observed that retinal ganglion cells (RGCs) seemed to be the cells most susceptible to VEGF-A antagonism, so we looked at anterograde transport in these cells, due to their long axons requiring optimal protein and organelle trafficking. Using cholera toxin B-subunit tracer studies, we found a distal reduction in transport in the superior colliculus following VEGF-A neutralization, which occurred prior to net RGC loss. This phenomenon of distal transport loss has been described as a feature of early pathological changes in glaucoma, Alzheimer's and Parkinson's disease models. Furthermore, we observed increased phosphorylation of p38 MAPK and downstream Hsp27 stress pathway signaling in the retinas from these experiments, potentially providing a mechanistic explanation for our findings. These experiments further highlight the possible risks of using VEGF-A antagonists to treat ocular neovascular disease, and suggest that VEGF-A may contribute to the maintenance and function of axonal transport in neurons of the retina. PMID:27148685

  8. Distal retinal ganglion cell axon transport loss and activation of p38 MAPK stress pathway following VEGF-A antagonism.

    PubMed

    Foxton, R; Osborne, A; Martin, K R; Ng, Y-S; Shima, D T

    2016-01-01

    There is increasing evidence that VEGF-A antagonists may be detrimental to neuronal health following ocular administration. Here we investigated firstly the effects of VEGF-A neutralization on retinal neuronal survival in the Ins2(Akita) diabetic and JR5558 spontaneous choroidal neovascularization (CNV) mice, and then looked at potential mechanisms contributing to cell death. We detected elevated apoptosis in the ganglion cell layer in both these models following VEGF-A antagonism, indicating that even when vascular pathologies respond to treatment, neurons are still vulnerable to reduced VEGF-A levels. We observed that retinal ganglion cells (RGCs) seemed to be the cells most susceptible to VEGF-A antagonism, so we looked at anterograde transport in these cells, due to their long axons requiring optimal protein and organelle trafficking. Using cholera toxin B-subunit tracer studies, we found a distal reduction in transport in the superior colliculus following VEGF-A neutralization, which occurred prior to net RGC loss. This phenomenon of distal transport loss has been described as a feature of early pathological changes in glaucoma, Alzheimer's and Parkinson's disease models. Furthermore, we observed increased phosphorylation of p38 MAPK and downstream Hsp27 stress pathway signaling in the retinas from these experiments, potentially providing a mechanistic explanation for our findings. These experiments further highlight the possible risks of using VEGF-A antagonists to treat ocular neovascular disease, and suggest that VEGF-A may contribute to the maintenance and function of axonal transport in neurons of the retina. PMID:27148685

  9. RNase activity of sialic acid-binding lectin from bullfrog eggs drives antitumor effect via the activation of p38 MAPK to caspase-3/7 signaling pathway in human breast cancer cells

    PubMed Central

    Kariya, Yukiko; Tatsuta, Takeo; Sugawara, Shigeki; Kariya, Yoshinobu; Nitta, Kazuo; Hosono, Masahiro

    2016-01-01

    Sialic acid-binding lectin obtained from bullfrog eggs (SBL) induces cell death in cancer cells but not in normal cells. This antitumor effect is mediated through its ribo-nuclease (RNase) activity. However, the underlying molecular mechanisms remain unclear. We found that the p38 mitogen-activated protein kinase (MAPK) signaling pathway was activated when SBL induced cell death in three human breast cancer cell lines: SK-BR-3, MCF-7, and MDA-MB231. The suppression of p38 MAPK phosphorylation by a p38 MAPK inhibitor as well as short interference RNA knockdown of p38 MAPK expression significantly decreased cell death and increased the cell viability of SBL-treated MDA-MB231 cells. H103A, an SBL mutant lacking in RNase activity, showed decreased SBL-induced cell death compared with native SBL. However, the loss of RNase activity of SBL had no effect on its internalization into cells. The H103A mutant also displayed decreased phosphorylation of p38 MAPK. Moreover, SBL promoted caspase-3/7 activation followed by a cleavage of poly (ADP-ribose)-polymerase, whereas the SBL mutant, H103A, lost this ability. The SBL-induced caspase-3/7 activation was suppressed by the p38 MAPK inhibitor, SB203580, as well as pan-caspase inhibitor, zVAD-fmk. In the presence of zVAD-fmk, the SBL-induced cell death was decreased. In addition, the cell viability of SBL-treated MDA-MB231 cells recovered by zVAD-fmk treatment. Taken together, our results suggest that the RNase activity of SBL leads to breast cancer cell death through the activation of p38 MAPK followed by the activation of caspase-3/7. PMID:27513956

  10. Rosiglitazone attenuates NF-{kappa}B-dependent ICAM-1 and TNF-{alpha} production caused by homocysteine via inhibiting ERK{sub 1/2}/p38MAPK activation

    SciTech Connect

    Bai, Yong-Ping; Liu, Yu-Hui; Chen, Jia; Song, Tao; You, Yu; Tang, Zhen-Yan; Li, Yuan-Jian; Zhang, Guo-Gang . E-mail: xyzgg2006@sina.com

    2007-08-17

    Previous studies demonstrated an important interaction between nuclear factor-kappaB (NF-{kappa}B) activation and homocysteine (Hcy)-induced cytokines expression in endothelial cells and vascular smooth muscle cells. However, the underlying mechanism remains illusive. In this study, we investigated the effects of Hcy on NF-{kappa}B-mediated sICAM-1, TNF-{alpha} production and the possible involvement of ERK{sub 1/2}/p38MAPK pathway. The effects of rosiglitazone intervention were also examined. Our results show that Hcy increased the levels of sICAM-1 and TNF-{alpha} in cultured human umbilical vein endothelial cells (HUVECs) in a time- and concentration-dependent manner. This effect was significantly depressed by rosiglitazone and different inhibitors (PDTC, NF-{kappa}B inhibitor; PD98059, MEK inhibitor; SB203580, p38MAPK specific inhibitor; and staurosporine, PKC inhibitor). Next, we investigated the effect of Hcy on ERK{sub 1/2}/p38MAPK pathway and NF-{kappa}B activity in HUVECs. The results show that Hcy activated both ERK{sub 1/2}/p38MAPK pathway and NF-{kappa}B-DNA-binding activity. These effects were markedly inhibited by rosiglitazone as well as other inhibitors (SB203580, PD98059, and PDTC). Further, the pretreatment of staurosporine abrogated ERK{sub 1/2}/p38MAPK phosphorylation, suggesting that Hcy-induced ERK{sub 1/2}/p38MAPK activation is associated with PKC activity. Our results provide evidence that Hcy-induced NF-{kappa}B activation was mediated by activation of ERK{sub 1/2}/p38MAPK pathway involving PKC activity. Rosiglitazone reduces the NF-{kappa}B-mediated sICAM-1 and TNF-{alpha} production induced by Hcy via inhibition of ERK{sub 1/2}/p38MAPK pa0011thw.

  11. Celecoxib Inhibits the Lytic Activation of Kaposi's Sarcoma-Associated Herpesvirus through Down-Regulation of RTA Expression by Inhibiting the Activation of p38 MAPK.

    PubMed

    Chen, Jungang; Jiang, Liangyu; Lan, Ke; Chen, Xulin

    2015-05-01

    Kaposi's sarcoma associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD). KSHV's lytic replication cycle is critical for the pathogenesis of KSHV-associated diseases. Despite recent progress in the development of treatments for KSHV associated malignancies, these therapies are not completely efficacious and cause side effects. Therefore, more effective therapies with antiviral agents against KSHV are urgently needed. In this study, we identified celecoxib as an antiviral agent against KSHV. Our data suggest that celecoxib inhibits the lytic activation of KSHV through the down-regulation of the expression of the lytic switch protein, replication and transcription activator (RTA), by inhibiting the activation of p38 MAPK. Therefore, celecoxib may provide a candidate inhibitor for the therapeutic research of KSHV-related malignancies.

  12. Exogenous hydrogen sulfide promotes C6 glioma cell growth through activation of the p38 MAPK/ERK1/2-COX-2 pathways.

    PubMed

    Zhen, Yulan; Zhang, Wei; Liu, Chujie; He, Jing; Lu, Yun; Guo, Ruixian; Feng, Jianqiang; Zhang, Ying; Chen, Jingfu

    2015-11-01

    Hydrogen sulfide (H2S) participates in multifarious physiological and pathophysiologic progresses of cancer both in vitro and in vivo. We have previously demonstrated that exogenous H2S promoted liver cancer cells proliferation/anti‑apoptosis/angiogenesis/migration effects via amplifying the activation of NF-κB pathway. However, the effects of H2S on cancer cell proliferation and apoptosis are controversial and remain unclear in C6 glioma cells. The present study investigated the effects of exogenous H2S on cancer cells growth via activating p38 MAPK/ERK1/2-COX-2 pathways in C6 glioma cells. C6 glioma cells were treated with 400 µmol/l NaHS (a donor of H2S) for 24 h. The expression levels of phosphorylated (p)-p38 MAPK, total (t)-p38 MAPK, p-ERK1/2, t-ERK1/2, cyclooxygenase-2 (COX-2) and caspase-3 were measured by western blotting assay. Cell viability was detected by Cell Counting Kit-8 (CCK-8). Apoptotic cells were observed by Hoechst 33258 staining assay. Cell proliferation was directly detected under fully automatic inverted microscope. Exposure of C6 glioma cells to NaHS resulted in cell proliferation, as evidenced by an increase in cell viability. In addition, NaHS treatment reduced apoptosis, as indicated by the decreased apoptotic percentage and the cleaved caspase-3 expression. Importantly, exposure of the cells to NaHS increased the expression levels of p-p38 MAPK, p-ERK1/2 and COX-2. Notably, co-treatment of C6 glioma cells with 400 µmol/l NaHS and AOAA (an inhibitor of CBS) largely suppressed the above NaHS-induced effects. Combined treatment with NaHS and SB203580 (an inhibitor of p38 MAPK) or PD-98059 (an inhibitor of ERK1/2) resulted in the synergistic reduction of COX-2 expression and increase of caspase-3 expression, a decreased number of apoptotic cells, along with decreased cell viability. Combined treatment with NS-398 (an inhibitor of COX-2) and NaHS also resulted in the synergistic increase of caspase-3, a decreased in the

  13. p38 MAPK Inhibition Improves Synaptic Plasticity and Memory in Angiotensin II-dependent Hypertensive Mice

    PubMed Central

    Dai, Hai-long; Hu, Wei-yuan; Jiang, Li-hong; Li, Le; Gaung, Xue-feng; Xiao, Zhi-cheng

    2016-01-01

    The pathogenesis of hypertension-related cognitive impairment has not been sufficiently clarified, new molecular targets are needed. p38 MAPK pathway plays an important role in hypertensive target organ damage. Activated p38 MAPK was seen in AD brain tissue. In this study, we found that long-term potentiation (LTP) of hippocampal CA1 was decreased, the density of the dendritic spines on the CA1 pyramidal cells was reduced, the p-p38 protein expression in hippocampus was elevated, and cognitive function was impaired in angiotensin II-dependent hypertensive C57BL/6 mice. In vivo, using a p38 heterozygous knockdown mice (p38KI/+) model, we showed that knockdown of p38 MAPK in hippocampus leads to the improvement of cognitive function and hippocampal synaptic plasticity in angiotensin II-dependent p38KI/+ hypertensive mice. In vitro, LTP was improved in hippocampal slices from C57BL/6 hypertensive mice by treatment with p38MAPK inhibitor SKF86002. Our data demonstrated that p38 MAPK may be a potential therapeutic target for hypertension-related cognitive dysfunction. PMID:27283322

  14. Metformin combined with p38 MAPK inhibitor improves cisplatin sensitivity in cisplatin-resistant ovarian cancer

    PubMed Central

    XIE, YA; PENG, ZHENG; SHI, MINGXING; JI, MEI; GUO, HONGJUN; SHI, HUIRONG

    2014-01-01

    The aim of the present study was to determine the effects of metformin, combined with a p38 mitogen-activated protein kinase (MAPK) inhibitor, on the sensitivity of cisplatin-resistant ovarian cancer to cisplatin. The expression and distribution of phosphorylated p38 MAPK (P-p38 MAPK) was confirmed in drug-resistant and primary ovarian cancer tissues by immunohistochemistry and western blotting. A bromodeoxyuridine ELISA kit was used to analyze the effects of metformin, SB203580, a p38 MAPK inhibitor, and metformin combined with SB203580, on the cell proliferation of SKOV3/DDP cisplatin-resistant ovarian cancer cells. The protein expression of P-p38 MAPK was significantly higher in cisplatin-resistant ovarian cancer, as compared with the primary ovarian cancer tissues. Metformin combined with SB203580 significantly enhanced the sensitivity of SKOV3/DDP cells to cisplatin. In conclusion, the p38 MAPK signaling pathway may be associated with cisplatin-resistant ovarian cancer. Metformin, combined with the p38 MAPK inhibitor, significantly increased the sensitivity of SKOV3/DDP cells to cisplatin treatment. PMID:25118792

  15. Thymol has antifungal activity against Candida albicans during infection and maintains the innate immune response required for function of the p38 MAPK signaling pathway in Caenorhabditis elegans.

    PubMed

    Shu, Chengjie; Sun, Lingmei; Zhang, Weiming

    2016-08-01

    The Caenorhabditis elegans model can be used to study Candida albicans virulence and host immunity, as well as to identify plant-derived natural products to use against C. albicans. Thymol is a hydrophobic phenol compound from the aromatic plant thyme. In this study, the in vitro data demonstrated concentration-dependent thymol inhibition of both C. albicans growth and biofilm formation during different developmental phases. With the aid of the C. elegans system, we performed in vivo assays, and our results further showed the ability of thymol to increase C. elegans life span during infection, inhibit C. albicans colony formation in the C. elegans intestine, and increase the expression levels of host antimicrobial genes. Moreover, among the genes that encode the p38 MAPK signaling pathway, mutation of the pmk-1 or sek-1 gene decreased the beneficial effects of thymol's antifungal activity against C. albicans and thymol's maintenance of the innate immune response in nematodes. Western blot data showed the level of phosphorylation of pmk-1 was dramatically decreased against C. albicans. In nematodes, treatment with thymol recovered the dysregulation of pmk-1 and sek-1 gene expressions, the phosphorylation level of PMK-1 caused by C. albicans infection. Therefore, thymol may act, at least in part, through the function of the p38 MAPK signaling pathway to protect against C. albicans infection and maintain the host innate immune response to C. albicans. Our results indicate that the p38 MAPK signaling pathway plays a crucial role in regulating the beneficial effects observed after nematodes infected with C. albicans were treated with thymol. PMID:26783030

  16. Anti-Food Allergic Activity of Sulfated Polysaccharide from Gracilaria lemaneiformis is Dependent on Immunosuppression and Inhibition of p38 MAPK.

    PubMed

    Liu, Qing-Mei; Yang, Yang; Maleki, Soheila J; Alcocer, Marcos; Xu, Sha-Sha; Shi, Chao-Lan; Cao, Min-Jie; Liu, Guang-Ming

    2016-06-01

    Polysaccharides from Gracilaria lemaneiformis in particular possess various bioactive functions, but their antiallergic activity remains incompletely defined. Sulfated polysaccharide from Gracilaria lemaneiformis (GLSP) was obtained by water extraction and ethanol precipitation followed by column chromatography. BALB/c mice, RBL-2H3, and KU812 cells were used for verifying the anti food allergic activity of GLSP. According to the results of mice experiment, GLSP was able to alleviate allergy symptoms, to reduce TM-specific IgE and IgG1, to suppress Th2 cell polarization, and to promote the function of regulatory T (Treg) cells. In addition, GLSP had the ability to inhibit the function of RBL-2H3 cells. Furthermore, GLSP inhibited the activation of KU812 via suppression of p38 mitogen-activated protein kinase (MAPK). In conclusion, immunosuppression as well as the reduction in the level of p38 MAPK may contribute to GLSP's putative activity against food allergy. GLSP may be used as a functional food component for allergic patients.

  17. Vesicular Stomatitis Virus Matrix Protein Impairs CD1d-Mediated Antigen Presentation through Activation of the p38 MAPK Pathway▿

    PubMed Central

    Renukaradhya, Gourapura J.; Khan, Masood A.; Shaji, Daniel; Brutkiewicz, Randy R.

    2008-01-01

    Natural killer T (NKT) cells are unique T lymphocytes that recognize CD1d-bound lipid antigens and play an important role in both innate and acquired immune responses against infectious diseases and tumors. We have already shown that a vesicular stomatitis virus (VSV) infection results in the rapid inhibition of murine CD1d-mediated antigen presentation to NKT cells. In the present study, it was found that the VSV matrix (VSV-M) protein is an important element in this decrease in antigen presentation postinfection. The VSV-M protein altered the intracellular distribution of murine CD1d molecules, resulting in qualitative (but not quantitative) changes in cell surface CD1d expression. The M protein was distributed throughout the infected cell, and it was found to activate the mitogen-activated protein kinase (MAPK) p38 very early postinfection. Infection of CD1d+ cells with a temperature-sensitive VSV-M mutant at the nonpermissive temperature both substantially reversed the inhibition of antigen presentation by CD1d and delayed the activation of p38. Thus, the VSV-M protein plays an important role in permitting the virus to evade important components of the innate immune response by regulating specific MAPK pathways. PMID:18815300

  18. Polycyclic aromatic hydrocarbon (PAH)-mediated upregulation of hepatic microRNA-181 family promotes cancer cell migration by targeting MAPK phosphatase-5, regulating the activation of p38 MAPK

    SciTech Connect

    Song, Mi-Kyung; Park, Yong-Keun; Ryu, Jae-Chun

    2013-11-15

    Growing evidence indicates that changes in microRNA (miRNA) expression in cancer induced by chemical carcinogens play an important role in cancer development and progression by regulating related genes. However, the mechanisms underlying miRNA involvement in hepatocarcinogenesis induced by polycyclic aromatic hydrocarbons (PAHs) remain unclear. Thus, the identification of aberrant miRNA expression during PAH-induced cancer cell migration will lead to a better understanding of the substantial role of miRNAs in cancer progression. In the present study, miRNA expression profiling showed significant upregulation of miR-181a, -181b, and -181d in human hepatocellular carcinoma cells (HepG2 line) exposed to benzo[a]anthracene (BA) and benzo[k]fluoranthene (BF). MAPK phosphatase-5 (MKP-5), a validated miR-181 target that deactivates MAPKs, was markedly suppressed while phosphorylation of p38 MAPK was increased after BA and BF exposure. The migration of HepG2 cells, observed using the scratch wound-healing assay, also increased in a dose-dependent manner. Depletion of miR-181 family members by miRNA inhibitors enhanced the expression of MKP-5 and suppressed the phosphorylation of p38 MAPK. Furthermore, the depletion of the miR-181 family inhibited cancer cell migration. Based on these results, we conclude that the miR-181 family plays a critical role in PAH-induced hepatocarcinogenesis by targeting MKP-5, resulting in the regulation of p38 MAPK activation. - Highlights: • We found significant upregulation of miR-181 family in HCC exposed to BA and BF. • We identified the MKP-5 as a putative target of miR-181 family. • MKP-5 was suppressed while p-P38 was increased after BA and BF exposure. • The migration of HepG2 cells increased in a dose-dependent manner.

  19. Non-mutagenic Suppression of Enterocyte Ferroportin 1 by Chemical Ribosomal Inactivation via p38 Mitogen-activated Protein Kinase (MAPK)-mediated Regulation: EVIDENCE FOR ENVIRONMENTAL HEMOCHROMATOSIS.

    PubMed

    Oh, Chang-Kyu; Park, Seong-Hwan; Kim, Juil; Moon, Yuseok

    2016-09-16

    Iron transfer across the basolateral membrane of an enterocyte into the circulation is the rate-limiting step in iron absorption and is regulated by various pathophysiological factors. Ferroportin (FPN), the only known mammalian iron exporter, transports iron from the basolateral surface of enterocytes, macrophages, and hepatocytes into the blood. Patients with genetic mutations in FPN or repeated blood transfusion develop hemochromatosis. In this study, non-mutagenic ribosomal inactivation was assessed as an etiological factor of FPN-associated hemochromatosis in enterocytes. Non-mutagenic chemical ribosomal inactivation disrupted iron homeostasis by regulating expression of the iron exporter FPN-1, leading to intracellular accumulation in enterocytes. Mechanistically, a xenobiotic insult stimulated the intracellular sentinel p38 MAPK signaling pathway, which was positively involved in FPN-1 suppression by ribosomal dysfunction. Moreover, ribosomal inactivation-induced iron accumulation in Caenorhabditis elegans as a simplified in vivo model for gut nutrition uptake was dependent on SEK-1, a p38 kinase activator, leading to suppression of FPN-1.1 expression and iron accumulation. In terms of gene regulation, ribosomal stress-activated p38 signaling down-regulated NRF2 and NF-κB, both of which were positive transcriptional regulators of FPN-1 transcription. This study provides molecular evidence for the modulation of iron bioavailability by ribosomal dysfunction as a potent etiological factor of non-mutagenic environmental hemochromatosis in the gut-to-blood axis.

  20. Tiliroside, the major component of Agrimonia pilosa Ledeb ethanol extract, inhibits MAPK/JNK/p38-mediated inflammation in lipopolysaccharide-activated RAW 264.7 macrophages

    PubMed Central

    JIN, XIN; SONG, SHIQING; WANG, JING; ZHANG, QINGZHEN; QIU, FENG; ZHAO, FENG

    2016-01-01

    In the present study, the in vivo anti-inflammatory activity of Agrimonia pilosa Ledeb (AP) ethanol extract was confirmed in experimental animal models, including xylene-induced ear edema in mice and carrageenan-induced paw edema in rats. Tiliroside, the major component of AP extract, was isolated and purified by high-performance liquid chromatography. The anti-inflammatory mechanism of tiliroside was then examined using lipopolysaccharide (LPS)-activated RAW 264.7 macrophage cells. An MTT assay was used to determine cytotoxicity and a Griess assay was used to determine nitric oxide (NO) production. Concentration levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by enzyme-linked immunosorbent assay. Protein expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), phosphorylated (p)-extracellular signal-regulated kinase (ERK) 1/2, p-c-Jun N-terminal kinases (JNK), p-p38 and inhibitor of κB-α were detected by western blot analysis. AP ethanol extract was revealed to inhibit xylene-induced ear edema in mice and carrageenan-induced paw edema in rats. Tiliroside significantly suppressed the overproduction of NO (P<0.01), but revealed no notable inhibition of the release of TNF-α and IL-6. In addition, tiliroside significantly downregulated the elevated expression levels of iNOS and COX-2 induced by LPS (P<0.01). The phosphorylation of JNK and p38 proteins were also significantly inhibited (P<0.01), however, tiliroside exhibited no obvious inhibition on the phosphorylation of ERK 1/2 and the degradation of IκB-α protein. In conclusion, the anti-inflammatory molecular mechanism of tiliroside may involve the downregulation of iNOS and COX-2 protein expression levels, and the inactivation of mitogen-activated protein kinase (MAPK)/JNK, in addition to the MAPK/p38 signaling pathway. PMID:27347085

  1. Indomethacin induces increase in gastric epithelial tight junction permeability via redistribution of occludin and activation of p38 MAPK in MKN-28 Cells.

    PubMed

    Thakre-Nighot, Meghali; Blikslager, Anthony T

    2016-01-01

    Tight Junctions (TJ) create a paracellular barrier that is compromised when nonsteriodal anti-inflammatory drugs (NSAIDs) injure the gastric epithelium, leading to increased permeability. However, the mechanism of NSAID-induced gastric injury is unclear. Here, we examined the effect of indomethacin on barrier function and TJ in gastric MKN-28 cells. In concentration response studies, 500 µm indomethacin induced a significant decrease in transepithelial resistance (TER; 380 vs. 220 Ω·cm(2) for control and indomethacin-treated cells respectively, p < 0.05), and increased dextran permeability by 0.2 vs 1.2 g/l (p < 0.05). These changes in barrier function were completely ameliorated by the p38 MAPK inhibitor (SB-203580) but not by JNK inhibitor (SP-600125) or MEK/ERK inhibitor (PD-98059). SiRNA knock down of p38 MAPK prevented the loss of barrier function caused by indomethacin in MKN-28 cells. Western analyses of TJ proteins revealed that expression of occludin was reduced by indomethacin, whereas there was no change in other TJ proteins. The loss of occludin expression induced by indomethacin was prevented by inhibition of p38 MAPK but not JNK or ERK and also by siRNA of p38 MAPK. Immunofluorescence revealed disruption of occludin localization at the site of the tight junction in indomethacin-treated cells, and this was attenuated by inhibition of p38 MAPK. NSAID injury to murine gastric mucosa on Ussing chambers revealed that indomethacin caused a significant drop in TER and increased paracellular permeability. Pretreatment with the p38 MAPK inhibitor significantly attenuated the disruption of barrier function, but JNK and MEK/ERK inhibition had no effect. Western blot analysis on gastric mucosa reveled loss of TJ protein occludin by indomethacin, which was prevented by inhibition of p38 MAPK. This data suggests that indomethacin compromises the gastric epithelial barrier via p38 MAPK inducing occludin alterations in the TJs. PMID:27583191

  2. Cross-talk between p(38)MAPK and G iα in regulating cPLA 2 activity by ET-1 in pulmonary smooth muscle cells.

    PubMed

    Chakraborti, Sajal; Chowdhury, Animesh; Chakraborti, Tapati

    2015-02-01

    Endothelin-1 (ET-1) is known as the most potent vasoconstrictor yet described. Infusion of ET-1 into isolated rabbit lung has been shown to cause pulmonary vasoconstriction with the involvement of arachidonic acid metabolites. Given the potency of arachidonic acid metabolites, the activity of phospholipase A2 must be tightly regulated. Herein, we determined the mechanisms by which ET-1 stimulates cPLA2 activity during ET-1 stimulation of bovine pulmonary artery smooth muscle cells. We demonstrated that (i) treatment of bovine pulmonary artery smooth muscle cells with ET-1 stimulates cPLA2 activity in the cell membrane; (ii) ET-1 caused increase in O 2 (·-) production occurs via NADPH oxidase-dependent mechanism; (iii) ET-1-stimulated NADPH oxidase activity is markedly prevented upon pretreatment with PKC-ζ inhibitor, indicating that PKC-ζ plays a prominent role in this scenario; (iv) ET-1-induced NADPH oxidase-derived O 2 (·-) stimulates an aprotinin sensitive protease activity due to prominent increase in [Ca(2+)]i; (v) the aprotinin sensitive protease plays a pivotal role in activating PKC-α, which in turn phosphorylates p(38)MAPK and subsequently Giα leading to the activation of cPLA2. Taken together, we suggest that cross-talk between p(38)MAPK and Giα with the involvement of PKC-ζ, NADPH oxidase-derived O 2 (·-) , [Ca(2+)]i, aprotinin-sensitive protease and PKC-α play a pivotal role for full activation of cPLA2 during ET-1 stimulation of pulmonary artery smooth muscle cells.

  3. A specific mechanomodulatory role for p38 MAPK in embryonic joint articular surface cell MEK-ERK pathway regulation.

    PubMed

    Lewthwaite, Jo C; Bastow, Edward R; Lamb, Katherine J; Blenis, John; Wheeler-Jones, Caroline P D; Pitsillides, Andrew A

    2006-04-21

    Mechanisms regulating cell behavior and extracellular matrix composition in response to mechanical stimuli remain unresolved. Our previous studies have established that the MEK-ERK cascade plays a specific role in the mechano-dependent joint formation process by promoting the assembly of pericellular matrices reliant upon hyaluronan (HA) for their integrity. Here we demonstrate: (i) novel cross-talk between p38 MAPK and MEK-ERK signaling pathways that is specific for mechanical stimuli and (ii) a role for p38 MAPK in facilitating HA production by cells derived from the articular surface of embryonic chick tibiotarsal joints. We find that p38 MAPK blockade restricts pericellular assembly of HA-rich matrices and reduces basal as well as mechanical strain-induced release of HA. p38 MAPK blockers potentiated early strain-induced increases but restricted sustained increases in MEK/ERK phosphorylation at later times; c-Fos hyperphosphorylation at threonine 325 was found to parallel this p38 MAPK-mediated modulation of ERK activation. In contrast, p38 MAPK inhibitors had no detectable effect on the ERK activation induced by fibroblast growth factor 2 or pervanadate, a phosphatase inhibitor, and MEK inhibitors did not influence p38 MAPK phosphorylation, confirming both the specificity and unidirectionality of p38 MAPK-ERK cross-talk. Immunochemical and immunoblotting studies revealed constitutive p38 MAPK activation in cells at, or derived from, developing articular joint surfaces. Unlike the MEK-ERK pathway, however, p38 MAPK was not further stimulated by mechanical stimulation in vitro. Thus, p38 MAPK specifically facilitates ERK activation and downstream signaling in response to mechanical stimuli. These results suggest that constitutively active p38 MAPK serves an essential, permissive role in mechanically induced changes in ERK activation and in the accumulation of HA-rich extracellular matrices that serve a key role in joint development.

  4. Prodigiosin isolated from Hahella chejuensis suppresses lipopolysaccharide-induced NO production by inhibiting p38 MAPK, JNK and NF-kappaB activation in murine peritoneal macrophages.

    PubMed

    Huh, Jung-Eun; Yim, Joung-Han; Lee, Hong-Kum; Moon, Eun-Yi; Rhee, Dong-Kwon; Pyo, Suhkneung

    2007-12-15

    Prodigiosin was isolated from marine bacteria Hahella chejuensis which has been recently discovered from Marado, Cheju Island, Republic of Korea. Immunosuppressive properties have been reported for prodigiosin members such as undecylprodigiosin, metacycloprodigiosin, prodigiosin and its synthetic analogue PNU156804 (PNU). However, the effect of this agent on macrophage function has not been characterized in detail. In the present study, we examined the effects of prodigiosin on the production of inflammatory cytokines and nitric oxide (NO) in lipopolysaccharide (LPS)-activated murine macrophage. When thioglycollate-elicited macrophages pre-exposed to prodigiosin (1-100 ng/ml) were stimulated with LPS, pretreatment with prodigiosin resulted in the inhibition of NO production and inducible nitric oxide synthase (iNOS) protein and mRNA expression in a concentration-dependent manner. In contrast, the production of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and IL-6 was not altered. Inhibition of iNOS protein expression appears to be at the transcriptional level, since prodigiosin decreased LPS-induced NF-kappaB activity through preventing the degradation of IkBalpha, with significant inhibition achieved following pretreatment with prodigiosin. However, prodigiosin did not exert any effect on AP-1 activity. Prodigiosin blocked phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun NH(2)-terminal kinase (JNK), but not that of extracellular signal-regulated kinase 1/2 (ERK 1/2). These results indicate that the inhibition of these signaling molecules expression was correlated with the reduced production of NO in macrophages. Taken together, the present data suggest that prodigiosin reduces NO production and iNOS expression by inhibiting LPS-triggered p38 MAPK and JNK phosphorylation and NF-kappaB activation, thereby implicating a mechanism by which prodigiosin may exert its immunosuppressive effects.

  5. Extracellular acidification synergizes with PDGF to stimulate migration of mouse embryo fibroblasts through activation of p38MAPK with a PTX-sensitive manner

    SciTech Connect

    An, Caiyan; Sato, Koichi; Wu, Taoya; Bao, Muqiri; Bao, Liang; Tobo, Masayuki; Damirin, Alatangaole

    2015-05-01

    The elucidation of the functional mechanisms of extracellular acidification stimulating intracellular signaling pathway is of great importance for developing new targets of treatment for solid tumors, and inflammatory disorders characterized by extracellular acidification. In the present study, we focus on the regulation of extracellular acidification on intracellular signaling pathways in mouse embryo fibroblasts (MEFs). We found extracellular acidification was at least partly involved in stimulating p38MAPK pathway through PTX-sensitive behavior to enhance cell migration in the presence or absence of platelet-derived growth factor (PDGF). Statistical analysis showed that the actions of extracellular acidic pH and PDGF on inducing enhancement of cell migration were not an additive effect. However, we also found extracellular acidic pH did inhibit the viability and proliferation of MEFs, suggesting that extracellular acidification stimulates cell migration probably through proton-sensing mechanisms within MEFs. Using OGR1-, GPR4-, and TDAG8-gene knock out technology, and real-time qPCR, we found known proton-sensing G protein-coupled receptors (GPCRs), transient receptor potential vanilloid subtype 1 (TRPV1), and acid-sensing ion channels (ASICs) were unlikely to be involved in the regulation of acidification on cell migration. In conclusion, our present study validates that extracellular acidification stimulates chemotactic migration of MEFs through activation of p38MAPK with a PTX-sensitive mechanism either by itself, or synergistically with PDGF, which was not regulated by the known proton-sensing GPCRs, TRPV1, or ASICs. Our results suggested that others proton-sensing GPCRs or ion channels might exist in MEFs, which mediates cell migration induced by extracellular acidification in the presence or absence of PDGF. - Highlights: • Acidic pH and PDGF synergize to stimulate MEFs migration via Gi/p38MAPK pathway. • Extracellular acidification inhibits the

  6. A Mechanism of Male Germ Cell Apoptosis Induced by Bisphenol-A and Nonylphenol Involving ADAM17 and p38 MAPK Activation

    PubMed Central

    Moreno, Ricardo D.

    2014-01-01

    Germ cell apoptosis regulation is pivotal in order to maintain proper daily sperm production. Several reports have shown that endocrine disruptors such as Bisphenol-A (BPA) and Nonylphenol (NP) induce germ cell apoptosis along with a decrease in sperm production. Given their ubiquitous distribution in plastic products used by humans it is important to clarify their mechanism of action. TACE/ADAM17 is a widely distributed extracellular metalloprotease and participates in the physiological apoptosis of germ cells during spermatogenesis. The aims of this work were: 1) to determine whether BPA and NP induce ADAM17 activation; and 2) to study whether ADAM17 and/or ADAM10 are involved in germ cell apoptosis induced by BPA and NP in the pubertal rat testis. A single dose of BPA or NP (50 mg/kg) induces germ cell apoptosis in 21-day-old male rats, which was prevented by a pharmacological inhibitor of ADAM17, but not by an inhibitor of ADAM10. In vitro, we showed that BPA and NP, at similar concentrations to those found in human samples, induce the shedding of exogenous and endogenous (TNF-α) ADAM17 substrates in primary rat Sertoli cell cultures and TM4 cell line. In addition, pharmacological inhibitors of metalloproteases and genetic silencing of ADAM17 prevent the shedding induced in vitro by BPA and NP. Finally, we showed that in vivo BPA and NP induced early activation (phosphorylation) of p38 MAPK and translocation of ADAM17 to the cell surface. Interestingly, the inhibition of p38 MAPK prevents germ cell apoptosis and translocation of ADAM17 to the cell surface. These results show for the first time that xenoestrogens can induce activation of ADAM17 at concentrations similar to those found in human samples, suggesting a mechanism by which they could imbalance para/juxtacrine cell-to-cell-communication and induce germ cell apoptosis. PMID:25474107

  7. Activation of p38 and JNK MAPK pathways abrogates requirement for new protein synthesis for phorbol ester mediated induction of select MMP and TIMP genes.

    PubMed

    Sampieri, Clara L; Nuttall, Robert K; Young, David A; Goldspink, Deborah; Clark, Ian M; Edwards, Dylan R

    2008-03-01

    The human matrix metalloproteinase (MMP) gene family includes 24 genes whose regulated expression, together with that of four tissue inhibitors of metalloproteinases (TIMPs), is essential in tissue remodelling and cell signalling. Quantitative real-time-PCR (qPCR) analysis was used to evaluate the shared and unique patterns of control of these two gene families in human MRC-5 and WI-38 fibroblasts in response to the protein kinase C (PKC) activator phorbol-12-myristate-13-acetate (PMA). The requirement for ongoing translation was analysed using three protein synthesis inhibitors, anisomycin, cycloheximide and emetine. PMA induced MMP1, 3, 8, 9, 10, 12, 13, 14 and TIMP1 and TIMP3 RNAs after 4-8 h, and induction of all except MMP9 and TIMP3 was blocked by all protein synthesis inhibitors. However, even though all inhibitors effectively blocked translation, PMA-induction of MMP9 and TIMP3 was blocked by emetine but was insensitive to cycloheximide and anisomycin. Anisomycin alone induced MMP9 and TIMP3, along with MMP25 and MMP19. The extracellular signal-regulated kinases (ERKs)-1/2 were strongly activated by PMA, while anisomycin activated the c-Jun N-terminal kinase (JNK) and p38 pathways, and cycloheximide activated p38, but emetine had no effect on the stress-activated mitogen-activated protein kinase (MAPK) pathways. The involvement of the p38 and JNK pathways in the selective effects of anisomycin and cycloheximide on MMP/TIMP expression was supported by use of pharmacological inhibitors. These data confirm that most inducible MMPs and TIMP1 behave as "late" activated, protein synthesis-dependent genes in fibroblasts. However, the requirement of protein synthesis for PMA-induction of MMPs and TIMPs is not universal, since it is abrogated for MMP9 and TIMP3 by stimulation of the stress-activated MAPK pathways. The definition of clusters of co-regulated genes among the two gene families will aid in bioinformatic dissection of control mechanisms.

  8. p38MAPK: stress responses from molecular mechanisms to therapeutics

    PubMed Central

    Coulthard, Lydia R.; White, Danielle E.; Jones, Dominic L.; McDermott, Michael F.; Burchill, Susan A.

    2010-01-01

    The p38MAPK protein kinases affect a variety of intracellular responses, with well-recognized roles in inflammation, cell-cycle regulation, cell death, development, differentiation, senescence and tumorigenesis. In this review, we examine the regulatory and effector components of this pathway, focusing on their emerging roles in biological processes involved in different pathologies. We summarize how this pathway has been exploited for the development of therapeutics and discuss the potential obstacles of targeting this promiscuous protein kinase pathway for the treatment of different diseases. Furthermore, we discuss how the p38MAPK pathway might be best exploited for the development of more effective therapeutics with minimal side effects in a range of specific disease settings. PMID:19665431

  9. Activation of the calcium-sensing receptor promotes apoptosis by modulating the JNK/p38 MAPK pathway in focal cerebral ischemia-reperfusion in mice

    PubMed Central

    Zhen, Yilan; Ding, Caijuan; Sun, Jiaqiang; Wang, Yanan; Li, Sheng; Dong, Liuyi

    2016-01-01

    Exact mechanism of cerebral ischemic stroke remains unclear. The calcium-sensing receptor (CaSR), a G-protein coupled receptor, has been reported to participate in the pathology of myocardial ischemia-reperfusion (I/R) injury and myocardial hypertrophy. Nevertheless, only a limited number of studies have been conducted to investigate the role of CaSR in cerebral ischemic stroke. This study was to investigate the effect of CaSR activation on cerebral ischemic stroke. Male adult Kunming mice were subjected to 2-h focal cerebral ischemia followed by 22-h reperfusion. Then, the brain was collected, and the expression of CaSR, JNK, p38, Bcl-2, and Bax was detected by Western blot assay. The morphology of neurons in the brain was evaluated by HE staining. Neurological function was scored, and the infarct volume was determined by TTC (triphenyltetrazolium chloride) staining. Results showed that ischemia/reperfusion (I/R) increased CaSR expression and induced neuronal apoptosis in the brain. Gadolinium trichloride (GdCl3), an agonist of CaSR, further deteriorated neurological dysfunction, increased infarct volume, enhanced CaSR expression, and promoted neuronal apoptosis. In addition, GdCl3 unregulated expression of Bax, p-JNK, and p-p38, and down-regulated Bcl-2 expression during I/R, which were attenuated by NPS2390, an inhibitor of CaSR. In conclusion, the CaSR activation promotes apoptosis in focal cerebral I/R in mice, which may be related to the activation of JNK/p38 MAPK signalling pathway. Targeting CaSR may be a novel strategy for the prevention and treatment of cerebral ischemic stroke. PMID:27158378

  10. Comparative chemical array screening for p38γ/δ MAPK inhibitors using a single gatekeeper residue difference between p38α/β and p38γ/δ

    PubMed Central

    Kondoh, Yasumitsu; Honda, Kaori; Hiranuma, Sayoko; Hayashi, Teruo; Shimizu, Takeshi; Watanabe, Nobumoto; Osada, Hiroyuki

    2016-01-01

    Mammalian p38 mitogen activated protein kinases (MAPKs) are responsive to a variety of cellular stresses. The development of specific pyridinyl imidazole inhibitors has permitted the characterization of the p38 MAPK isoform p38α, which is expressed in most cell types, whereas the physiological roles of p38γ and p38δ are poorly understood. In this study, we report an approach for identifying selective inhibitors against p38γ and p38δ by focusing on the difference in gatekeeper residues between p38α/β and p38γ/δ. Using GST-fused p38α wild type and T106M mutant constructs, wherein the p38α gatekeeper residue (Thr-106) was substituted by the p38γ/δ-type (Met), we performed comparative chemical array screening to identify specific binders of the mutant and identified SU-002 bound to p38αT106M specifically. SU-002 was found to inhibit p38αT106M but not p38α kinase activity in in vitro kinase assays. SU-005, the analog of SU-002, had inhibitory effects against the kinase activity of p38γ and p38δ in vitro but not p38α. In addition, SU-005 inhibited both p38γ and p38δ auto-phosphorylation in HeLa and HEK293T cells. These results demonstrate that the comparative chemical array screening approach is a powerful technique to explore specific inhibitors for mutant proteins with even single amino-acid substitutions in a high-throughput manner. PMID:27431267

  11. A novel lipopeptide from skin commensal activates TLR2/CD36-p38 MAPK signaling to increase antibacterial defense against bacterial infection.

    PubMed

    Li, Dongqing; Lei, Hu; Li, Zhiheng; Li, Hongquan; Wang, Yue; Lai, Yuping

    2013-01-01

    Staphylococcus epidermidis (S.epidermidis) plays important protective roles by directly producing or by stimulating hosts to produce antimicrobial peptides (AMPs) against pathogenic infections. Although several AMPs from S.epidermidis have been identified, molecules that stimulate hosts to produce AMPs remain largly unknown. Here we demonstrate that a new lipopeptide (named LP01) purified from S.epidermidis culture media has a unique structure with heneicosanoic acid (21 carbons) binding to lysine(11) of a peptide chain. In vitro LP01 increased the expression of β-defensin 2(hBD2) and hBD3 in neonatal human epidermal keratinocytes(NHEK), leading to increased capacity of cell lysates to inhibit the growth of S.aureus. In vivo LP01 induced the expression of mouse β-defensin 4(mBD4) to decrease the survival of local S.aureus in skin and systemic S.aureus survival in liver. The induction of beta-defensins by LP01 was dependent on TLR2 as Tlr2-deficient mice had decreased mBD4. Furthermore, knockdown of CD36 decreased the expression of hBD2 and hBD3, and p38 MAPK inhibitor significantly inhibited the expression of hBDs induced by LP01.Taken together, these findings demonstrate that lipopeptide LP01 from normal commensal S.epidermidis increases antimicrobial peptide hBD2 and hBD3 expression via the activation of TLR2/CD36-p38 MAPK, thus enhancing antimicrobial defense against pathogenic infections.

  12. The Role of p38 MAPK in the Development of Diabetic Cardiomyopathy.

    PubMed

    Wang, Shudong; Ding, Lijuan; Ji, Honglei; Xu, Zheng; Liu, Quan; Zheng, Yang

    2016-01-01

    Diabetic cardiomyopathy (DCM) is a major complication of diabetes that contributes to an increase in mortality. A number of mechanisms potentially explain the development of DCM including oxidative stress, inflammation and extracellular fibrosis. Mitogen-activated protein kinase (MAPK)-mediated signaling pathways are common among these pathogenic responses. Among the diverse array of kinases, extensive attention has been given to p38 MAPK due to its capacity for promoting or inhibiting the translation of target genes. Growing evidence has indicated that p38 MAPK is aberrantly expressed in the cardiovascular system, including the heart, under both experimental and clinical diabetic conditions and, furthermore, inhibition of p38 MAPK activation in transgenic animal model or with its pharmacologic inhibitor significantly prevents the development of DCM, implicating p38 MAPK as a novel diagnostic indicator and therapeutic target for DCM. This review summarizes our current knowledge base to provide an overview of the impact of p38 MAPK signaling in diabetes-induced cardiac remodeling and dysfunction. PMID:27376265

  13. The Role of p38 MAPK in the Development of Diabetic Cardiomyopathy

    PubMed Central

    Wang, Shudong; Ding, Lijuan; Ji, Honglei; Xu, Zheng; Liu, Quan; Zheng, Yang

    2016-01-01

    Diabetic cardiomyopathy (DCM) is a major complication of diabetes that contributes to an increase in mortality. A number of mechanisms potentially explain the development of DCM including oxidative stress, inflammation and extracellular fibrosis. Mitogen-activated protein kinase (MAPK)-mediated signaling pathways are common among these pathogenic responses. Among the diverse array of kinases, extensive attention has been given to p38 MAPK due to its capacity for promoting or inhibiting the translation of target genes. Growing evidence has indicated that p38 MAPK is aberrantly expressed in the cardiovascular system, including the heart, under both experimental and clinical diabetic conditions and, furthermore, inhibition of p38 MAPK activation in transgenic animal model or with its pharmacologic inhibitor significantly prevents the development of DCM, implicating p38 MAPK as a novel diagnostic indicator and therapeutic target for DCM. This review summarizes our current knowledge base to provide an overview of the impact of p38 MAPK signaling in diabetes-induced cardiac remodeling and dysfunction. PMID:27376265

  14. Soman poisoning alters p38 MAPK pathway in rat cerebellar Purkinje cells.

    PubMed

    Pejchal, Jaroslav; Osterreicher, Jan; Kassa, Jiri; Tichy, Ales; Micuda, Stanislav; Sinkorova, Zuzana; Zarybnicka, Lenka

    2009-05-01

    The aim of the study was to evaluate the expression of phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) and MAPK-activated transcription factors elk-1, c-jun and c-myc in rat cerebellar Purkinje cells after soman poisoning to investigate the pathogenetic mechanism of non-specific long-term adverse effects of nerve agents. Male Wistar rats were poisoned by intramuscular administration of soman at a dose 60 microg kg(-1) (80% LD(50)), while control animals were administered physiological saline. Samples were taken 1, 7 and 14 days after poisoning, immunohistochemically stained and p-p38MAPK, p-c-jun, p-c-myc, and p-elk-1 expressions were measured using computer image analysis. An increased expression of phosphorylated p38 MAPK and c-myc 14 days after soman poisoning was found, while both activated elk-1 and c-jun expression remained unchanged 1, 7 and 14 days after intoxication. Late activation of p38 MAPK and their targets might be the underlying mechanism of chronic neurophysiological adverse effects.

  15. Ferulic Acid Administered at Various Time Points Protects against Cerebral Infarction by Activating p38 MAPK/p90RSK/CREB/Bcl-2 Anti-Apoptotic Signaling in the Subacute Phase of Cerebral Ischemia-Reperfusion Injury in Rats

    PubMed Central

    Cheng, Chin-Yi; Tang, Nou-Ying; Kao, Shung-Te; Hsieh, Ching-Liang

    2016-01-01

    Objectives This study aimed to evaluate the effects of ferulic acid (FA) administered at various time points before or after 30 min of middle cerebral artery occlusion (MCAo) followed by 7 d of reperfusion and to examine the involvement of mitogen-activated protein kinase (MAPK) signaling pathways in the cortical penumbra. Methods FA was intravenously administered to rats at a dose of 100 mg/kg 24 h before ischemia (B-FA), 2 h before ischemia (P-FA), immediately after ischemic insult (I-FA), 2 h after reperfusion (R-FA), or 24 h after reperfusion (D-FA). Results Our study results indicated that P-FA, I-FA, and R-FA effectively reduced cerebral infarct areas and neurological deficits. P-FA, I-FA, and R-FA significantly downregulated glial fibrillary acidic protein (GFAP), mitochondrial Bax, cytochrome c, and cleaved caspase-3 expression, and effectively restored the phospho-p38 MAPK (p-p38 MAPK)/p38 MAPK ratio, phospho-90 kDa ribosomal S6 kinase (p-p90RSK) expression, phospho-Bad (p-Bad) expression, the phospho-cAMP response element-binding protein (p-CREB)/CREB ratio, the cytosolic and mitochondrial Bcl-2/Bax ratios, and the cytosolic Bcl-xL/Bax ratio in the cortical penumbra 7 d after reperfusion. SB203580, a specific inhibitor of p38 MAPK, administered 30 min prior to ischemia abrogated the downregulating effects of I-FA on cerebral infarction, and mitochondrial Bax and cleaved caspase-3 expression, and the upregulating effects of I-FA on the p-p38 MAPK/p38 MAPK ratio, p-p90RSK expression, p-Bad expression, and the p-CREB/CREB, and cytosolic and mitochondrial Bcl-2/Bax ratios. Conclusions Our study results thus indicate that P-FA, I-FA, and R-FA effectively suppress reactive astrocytosis and exert neuroprotective effects against cerebral infarction by activating p38 MAPK signaling. The regulating effects of P-FA, I-FA, and R-FA on Bax-induced apoptosis result from activation of the p38 MAPK/p90RSK/CREB/Bcl-2 signaling pathway, and eventually contribute to

  16. p38α MAPK is required for arsenic-induced cell transformation.

    PubMed

    Kim, Hong-Gyum; Shi, Chengcheng; Bode, Ann M; Dong, Zigang

    2016-05-01

    Arsenic exposure has been reported to cause neoplastic transformation through the activation of PcG proteins. In the present study, we show that activation of p38α mitogen-activated protein kinase (MAPK) is required for arsenic-induced neoplastic transformation. Exposure of cells to 0.5 μM arsenic increased CRE and c-Fos promoter activities that were accompanied by increases in p38α MAPK and CREB phosphorylation and expression levels concurrently with AP-1 activation. Introduction of short hairpin (sh) RNA-p38α into BALB/c 3T3 cells markedly suppressed arsenic-induced colony formation compared with wildtype cells. CREB phosphorylation and AP-1 activation were decreased in p38α knockdown cells after arsenic treatment. Arsenic-induced AP-1 activation, measured as c-Fos and CRE promoter activities, and CREB phosphorylation were attenuated by p38 inhibition in BALB/c 3T3 cells. Thus, p38α MAPK activation is required for arsenic-induced neoplastic transformation mediated through CREB phosphorylation and AP-1 activation.

  17. Activation of the MAPK11/12/13/14 (p38 MAPK) pathway regulates the transcription of autophagy genes in response to oxidative stress induced by a novel copper complex in HeLa cells.

    PubMed

    Zhong, Wu; Zhu, Haichuan; Sheng, Fugeng; Tian, Yonglu; Zhou, Jun; Chen, Yingyu; Li, Song; Lin, Jian

    2014-07-01

    Transition metal copper (Cu) can exist in oxidized or reduced states in cells, leading to cytotoxicity in cancer cells through oxidative stress. Recently, copper complexes are emerging as a new class of anticancer compounds. Here, we report that a novel anticancer copper complex (HYF127c/Cu) induces oxidative stress-dependent cell death in cancer cells. Further, transcriptional analysis revealed that oxidative stress elicits broad transcriptional changes of genes, in which autophagy-related genes are significantly changed in HYF127c/Cu-treated cells. Consistently, autophagy was induced in HYF127c/Cu-treated cells and inhibitors of autophagy promoted cell death induced by HYF127c/Cu. Further analysis identified that the MAPK11/12/13/14 (formerly known as p38 MAPK) pathway was also activated in HYF127c/Cu-treated cells. Meanwhile, the MAPK11/12/13/14 inhibitor SB203580 downregulated autophagy by inhibiting the transcription of the autophagy genes MAP1LC3B, BAG3, and HSPA1A, and promoted HYF127c/Cu-induced cell death. These data suggest that copper-induced oxidative stress will induce protective autophagy through transcriptional regulation of autophagy genes by activation of the MAPK11/12/13/14 pathway in HeLa cells.

  18. Inhibition of p38 MAPK during cellular activation modulate gene expression of head kidney leukocytes isolated from Atlantic salmon (Salmo salar) fed soy bean oil or fish oil based diets.

    PubMed

    Holen, E; Winterthun, S; Du, Z-Y; Krøvel, A V

    2011-01-01

    Head kidney leukocytes isolated from Atlantic salmon fed either a diet based on fish oil (FO) or soy bean oil (VO) were used in order to evaluate if different lipid sources could contribute to cellular activation of the salmon innate immune system. A specific inhibitor of p38 MAPK, SB202190, was used to investigate the effect of lipopolysaccharide (LPS) signalling in the head kidney leukocytes. The results show that LPS up regulate IL-1β, TNF-α, Cox2 expression in leukocytes isolated from fish fed either diet. The p38 MAPK inhibitor, SB202190, reduced the LPS induced expression of these genes in both dietary groups. In LPS stimulated leukocytes isolated from VO fed fish, SB202190 showed a clear dose dependent inhibitory effect on IL-1β, TNF-α and Cox2 expression. This effect was also observed for Cox2 in leukocytes isolated from FO fed fish. Furthermore, there was a stronger mean induction of Cox2 in LPS stimulated leucocytes isolated from the VO-group compared to LPS stimulated leukocytes isolated from the FO-group. In both dietary groups, LPS stimulation of salmon head kidney leukocytes increased the induction of CD83, a dendrite cell marker, while the inhibitor reduced CD83 expression in the VO fed fish only. The inhibitor also clearly reduced hsp27 expression in VO fed fish. Indicating a p38 MAPK feedback loop, LPS significantly inhibited the expression of p38MAPK itself in both diets, while SB202190 increased p38MAPK expression especially in the VO diet group. hsp70 expression was not affected by any treatment or feed composition. There were also differences in p38MAPK protein phosphorylation comparing treatment groups but no obvious difference comparing the two dietary groups. The results indicate that dietary fatty acids have the ability to modify signalling through p38 MAPK which may have consequences for the fish's ability to handle infections and stress. Signalling through p38MAPK is ligand dependent and affects gene and protein expression differently.

  19. Interleukin-10 Enhances the Intestinal Epithelial Barrier in the Presence of Corticosteroids through p38 MAPK Activity in Caco-2 Monolayers: A Possible Mechanism for Steroid Responsiveness in Ulcerative Colitis

    PubMed Central

    Lorén, Violeta; Cabré, Eduard; Ojanguren, Isabel; Domènech, Eugeni; Pedrosa, Elisabet; García-Jaraquemada, Arce; Mañosa, Miriam; Manyé, Josep

    2015-01-01

    Glucocorticosteroids are the first line therapy for moderate-severe flare-ups of ulcerative colitis. Despite that, up to 60% of patients do not respond adequately to steroid treatment. Previously, we reported that low IL-10 mRNA levels in intestine are associated with a poor response to glucocorticoids in active Crohn’s disease. Here, we test whether IL-10 can favour the response to glucocorticoids by improving the TNFα-induced intestinal barrier damage (assessed by transepithelial electrical resistance) in Caco-2 monolayers, and their possible implications on glucocorticoid responsiveness in active ulcerative colitis. We show that the association of IL-10 and glucocorticoids improves the integrity of TNFα-treated Caco-2 cells and that p38 MAPK plays a key role. In vitro, IL-10 facilitates the nuclear translocation of p38 MAPK-phosphorylated thereby modulating glucocorticoids-receptor-α, IL-10-receptor-α and desmoglein-2 expression. In glucocorticoids-refractory patients, p38 MAPK phosphorylation and membrane desmoglein-2 expression are reduced in colonic epithelial cells. These results suggest that p38 MAPK-mediated synergism between IL-10 and glucocorticoids improves desmosome straightness contributing to the recovery of intestinal epithelium and reducing luminal antigens contact with lamina propria in ulcerative colitis. This study highlights the link between the intestinal epithelium in glucocorticoids-response in ulcerative colitis. PMID:26090671

  20. Extracellular galectin-3 induces MMP9 expression by activating p38 MAPK pathway via lysosome-associated membrane protein-1 (LAMP1).

    PubMed

    Dange, Manohar C; Agarwal, Akhil Kumar; Kalraiya, Rajiv D

    2015-06-01

    Matrix metalloproteinases (MMPs) play a key role in matrix remodelling and thus invasion and metastasis. Extracellular galectin-3 has been shown to induce MMP9 secretion. Here, we demonstrate that galectin-3 induces MMP9 at transcript level and it is dependent on the surface levels of poly-N-acetyllactosamine (polyLacNAc). By employing signalling pathway inhibitors, MMP9 expression was shown to be induced via p38 MAP-kinase pathway. Using clones of melanoma cells expressing shRNAs to lysosome-associated membrane protein-1 (LAMP1), a major carrier of polyLacNAc, surface LAMP1 was demonstrated to serve as one of the key mediators of galectin-3-induced MMP9 expression via p38 MAPK pathway.

  1. Data on the phosphorylation of p38MAPK and JNK induced by chlorpyrifos in Drosophila melanogaster.

    PubMed

    Batista, J E S; Sousa, L R; Martins, I K; Rodrigues, N R; Posser, T; Franco, J L

    2016-12-01

    Exposure to organophosphate compounds, such as chlorpyrifos, has been linked to disturbances on cell signaling pathways. Mitogen activated protein kinases (MAPK) are a family of protein kinases involved in a range of cellular processes, including stress response, apoptosis and survival. Therefore, changes in the activation state of these kinases may characterize key mechanisms of toxicity elicited by xenobiotics. Here we report data on the phosphorylation of p38MAPK and JNK, members of the MAPK family, in Drosophila melanogaster exposed to chlorpyrifos, as characterized by western blotting assays. PMID:27626050

  2. Crotoxin induces apoptosis and autophagy in human lung carcinoma cells in vitro via activation of the p38MAPK signaling pathway

    PubMed Central

    Han, Rong; Liang, Hui; Qin, Zheng-hong; Liu, Chun-yu

    2014-01-01

    Aim: Crotoxin (CrTX) is the primary toxin in South American rattlesnake (Crotalus durissus terrificus) venom, and exhibits antitumor and other pharmacological actions in vivo and in vitro. Here, we investigated the molecular mechanisms of the antitumor action of CrTX in human lung carcinoma cells in vitro. Methods: Human lung squamous carcinoma SK-MES-1 cells were tested. The cytotoxicity of CrTX was evaluated in both MTT and colony formation assays. Cell cycle was investigated with flow cytometry. Cell apoptosis was studied with Hoechst 33258 and Annexin V-FITC staining. The levels of relevant proteins were analyzed using Western blot assays. Results: CrTX (25, 50, 100 μmol/L) inhibited the growth and colony formation of SK-MES-1 cells in dose- and time-dependent manners. CrTX increased the proportion of S phase cells and dose-dependently induced cell apoptosis, accompanied by down-regulating the expression of proliferating cell nuclear antigen (PCNA), and increasing the level of cleaved caspase-3. Furthermore, CrTX dose-dependently increased the expression of autophagy-related proteins LC3-II and beclin 1, and decreased the level of p62 in the cells. Moreover, CrTX (50 μmol/L) significantly increased p38MAPK phosphorylation in the cells. Pretreatment of the cells with SB203580, a specific inhibitor of p38MAPK, blocked the inhibition of CrTX on cell proliferation, as well as CrTX-induced apoptosis and cleaved caspase-3 expression. Conclusion: The p38MAPK signaling pathway mediates CrTX-induced apoptosis and autophagy of human lung carcinoma SK-MES-1 cells in vitro. PMID:25132339

  3. Lobolide, a diterpene, blockades the NF-κB pathway and p38 and ERK MAPK activity in macrophages in vitro

    PubMed Central

    Lv, Xiao-fen; Chen, Si-han; Li, Jie; Fang, Jian-ping; Guo, Yue-wei; Ding, Kan

    2012-01-01

    Aim: Recent studies have shown that constitutive activation of the nuclear factor κB (NF-κB) plays a key role in chronic inflammation and cancers. The aim of this study was to characterize lobolide, a cembrane diterpene, as a drug candidate targeting the NF-κB signaling pathway. Methods: A HEK 293/NF-κB-Luc stable cell line was constructed to evaluate the effect of lobolide on NF-κB activation. THP-1 human monocytes and peripheral blood mononuclear cells (PBMCs) from healthy volunteers were tested. Lipopolysaccharide (LPS)-induced TNFα and IL-1β production and activation of the TAK1-IKK-NF-κB pathway were studied using ELISA and Western blot analysis. Results: In HEK 293/NF-κB-Luc stable cells, lobolide (0.19–50 μmol/L) inhibited NF-κB activation in a concentration-dependent manner with an IC50 value of 4.2±0.3 μmol/L. Treatment with lobolide (2.5–10 μmol/L) significantly suppressed LPS-induced production of TNFα and IL-1β in both THP-1 cells and PBMCs. In THP-1 cells, the suppression was partially caused by blockade of the translocation of NF-κB from the cytoplasm to the nucleus via affecting the TAK1-IKK-NF-κB pathway and p38 and ERK MAPK activity. Conclusion: Lobolide is a potential inhibitor of the NF-κB pathway, which blocks the translocation of NF-κB from the cytoplasm to the nucleus. Lobolide inhibits LPS-stimulated TNFα and IL-1β release, suggesting that the compound might be an anti-inflammatory compound. PMID:22922340

  4. Oncogenic Ras modulates p38 MAPK-mediated inflammatory cytokine production in glioblastoma cells.

    PubMed

    Munoz, Lenka; Yeung, Yiu To; Grewal, Thomas

    2016-04-01

    Inflammation is an important factor promoting the progression of glioblastoma. In the present study we examined the contribution of Ras signaling and TNFα/IL-1β cytokines to the development of the glioblastoma inflammatory microenvironment. Enhanced activation of Ras through de-regulated activation of receptor tyrosine kinases, such as EGFR, PDGFR and cMet, is a hallmark of the majority of glioblastomas. Glioblastoma microenvironment contains high levels of TNFα and IL-1β, which mediate inflammation through induction of a local network of cytokines and chemokines. While many studies have focused on Ras- and TNFα/IL-1β-driven inflammation in isolation, little is known about the co-operation between these oncogenic and microenvironment-derived stimuli. Using constitutively active HRasG12V that mimics enhanced Ras activation, we demonstrate that elevated Ras activity in glioblastoma cells leads to up-regulation of IL-6 and IL-8. Furthermore, Ras synergizes with the microenvironment-derived TNFα and IL-1β resulting in amplified IL-6/IL-8 secretion. IL-8 secretion induced by Ras and TNFα/IL-1β is attenuated by inhibitors targeting Erk, JNK and p38 MAPK pathways. IL-6 secretion significantly decreased upon inhibition of JNK and p38 MAPK pathways. Interestingly, although constitutively active HRasG12V does not increase basal or TNFα/IL-1β stimulated p38 MAPK activity, HRasG12V increased the efficacy of the p38 MAPK inhibitor SB203580 to inhibit IL-1β-induced IL-6 secretion. In summary, oncogenic Ras co-operates with the microenvironment-derived TNFα/IL-1β to sustain inflammatory microenvironment, which was effectively attenuated via inhibition of p38 MAPK signaling. PMID:26794430

  5. p38δ MAPK phenotype: an indicator of chemotherapeutic response in oesophageal squamous cell carcinoma

    PubMed Central

    O’Callaghan, Carol; Fanning, Liam J.

    2015-01-01

    We recently documented p38δ differential expression and function in oesophageal squamous cell carcinoma (OESCC). This study expands upon these findings and investigates whether p38δ status in OESCC can influence response(s) to cytotoxic drugs. The antiproliferative effect of conventional cisplatin and 5-fluorouracil (CF) treatment was compared with the recently reviewed triple regime of cisplatin, 5-fluorouracil and doxorubicin (ACF). p38δ-positive and p38δ-negative cell lines were employed using cell-growth and clonogenic assays. Key regulators of intrinsic and extrinsic apoptotic pathways were measured. Wound-healing assays and a Boyden chamber were used to investigate the effect of drug treatments on cell migration. Functional networks were analysed in terms of changes in MAPK expression. p38δ-negative OESCC is less sensitive to standard CF chemotherapy compared with p38δ-positive cells. However, following ACF treatment p38δ-negative cells showed markedly decreased proliferation and cell migration, and increased apoptosis. ACF induced apoptosis through the extrinsic pathway involving Fas activation, caspase-8 and caspase-3 cleavage and degradation of PARP. Loss of mitochondrial membrane potential (ΔΨm) was observed but downregulation of multidomain proapoptotic proteins, as well as BH3-only proteins, suggests involvement of pathways other than the mitochondrial pathway. Interestingly, induction of p38 and ERK1/2, but not JNK1/2, was observed following ACF treatment. p38δ-negative OESCC is more resistant to traditional CF treatment compared with p38δ-positive OESCC. In light of these results, p38δ phenotyping of tumour tissue may be of considerable value in deciding on an optimal therapeutic strategy for patients with p38δ-negative OESCC. PMID:25099621

  6. p38δ MAPK phenotype: an indicator of chemotherapeutic response in oesophageal squamous cell carcinoma.

    PubMed

    O'Callaghan, Carol; Fanning, Liam J; Barry, Orla P

    2015-01-01

    We recently documented p38δ differential expression and function in oesophageal squamous cell carcinoma (OESCC). This study expands upon these findings and investigates whether p38δ status in OESCC can influence response(s) to cytotoxic drugs. The antiproliferative effect of conventional cisplatin and 5-fluorouracil (CF) treatment was compared with the recently reviewed triple regime of cisplatin, 5-fluorouracil and doxorubicin (ACF). p38δ-positive and p38δ-negative cell lines were employed using cell-growth and clonogenic assays. Key regulators of intrinsic and extrinsic apoptotic pathways were measured. Wound-healing assays and a Boyden chamber were used to investigate the effect of drug treatments on cell migration. Functional networks were analysed in terms of changes in MAPK expression. p38δ-negative OESCC is less sensitive to standard CF chemotherapy compared with p38δ-positive cells. However, following ACF treatment p38δ-negative cells showed markedly decreased proliferation and cell migration, and increased apoptosis. ACF induced apoptosis through the extrinsic pathway involving Fas activation, caspase-8 and caspase-3 cleavage and degradation of PARP. Loss of mitochondrial membrane potential (ΔΨm) was observed but downregulation of multidomain proapoptotic proteins, as well as BH3-only proteins, suggests involvement of pathways other than the mitochondrial pathway. Interestingly, induction of p38 and ERK1/2, but not JNK1/2, was observed following ACF treatment. p38δ-negative OESCC is more resistant to traditional CF treatment compared with p38δ-positive OESCC. In light of these results, p38δ phenotyping of tumour tissue may be of considerable value in deciding on an optimal therapeutic strategy for patients with p38δ-negative OESCC. PMID:25099621

  7. Huaier polysaccharide induces apoptosis in hepatocellular carcinoma cells through p38 MAPK

    PubMed Central

    Bao, Haidong; Liu, Peng; Jiang, Ke; Zhang, Xianbin; Xie, Long; Wang, Zhongyu; Gong, Peng

    2016-01-01

    The underlying mechanism of the antitumor activity of Huaier polysaccharide (HP) remains to be explored. The present study aimed to investigate the inhibitory effect of HP on hepatocellular carcinoma (HCC) cells, and to explore the possible mechanisms of its anticancer effect. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while apoptotic nuclear changes were observed using Hoechst 33258 staining. The distribution of cell cycle and apoptosis were analyzed by flow cytometry, and western blotting was used to test the apoptotic pathways. Apoptosis and mitogen-activated protein kinase (MAPK) inhibitors were used to investigate the mechanism of apoptosis. HP triggered cell cycle arrest and apoptosis in HepG2 and Huh7 cells. Both the extrinsic and intrinsic apoptotic pathways were activated after HP treatment. Furthermore, HP enhanced the three major MAPK pathways (extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38 MAPK) and inhibited the AKT/mechanistic target of rapamycin signaling pathway in HCC cells. Notably, the inactivation of p38 MAPK impaired the HP-induced cell death. HP exerted its antitumor effect on HCC cells through the regulation of the expression of the apoptosis-related proteins B-cell lymphoma (Bcl)-2, Bcl-2-associated X protein and survivin. The present study provides evidence that HP induces apoptosis in HCC cells and demonstrated the role of p38 MAPK in HP-triggered cancer cell death. PMID:27446394

  8. p38α MAPK is required for tooth morphogenesis and enamel secretion.

    PubMed

    Greenblatt, Matthew B; Kim, Jung-Min; Oh, Hwanhee; Park, Kwang Hwan; Choo, Min-Kyung; Sano, Yasuyo; Tye, Coralee E; Skobe, Ziedonis; Davis, Roger J; Park, Jin Mo; Bei, Marianna; Glimcher, Laurie H; Shim, Jae-Hyuck

    2015-01-01

    An improved understanding of the molecular pathways that drive tooth morphogenesis and enamel secretion is needed to generate teeth from organ cultures for therapeutic implantation or to determine the pathogenesis of primary disorders of dentition (Abdollah, S., Macias-Silva, M., Tsukazaki, T., Hayashi, H., Attisano, L., and Wrana, J. L. (1997) J. Biol. Chem. 272, 27678-27685). Here we present a novel ectodermal dysplasia phenotype associated with conditional deletion of p38α MAPK in ectodermal appendages using K14-cre mice (p38α(K14) mice). These mice display impaired patterning of dental cusps and a profound defect in the production and biomechanical strength of dental enamel because of defects in ameloblast differentiation and activity. In the absence of p38α, expression of amelogenin and β4-integrin in ameloblasts and p21 in the enamel knot was significantly reduced. Mice lacking the MAP2K MKK6, but not mice lacking MAP2K MKK3, also show the enamel defects, implying that MKK6 functions as an upstream kinase of p38α in ectodermal appendages. Lastly, stimulation with BMP2/7 in both explant culture and an ameloblast cell line confirm that p38α functions downstream of BMPs in this context. Thus, BMP-induced activation of the p38α MAPK pathway is critical for the morphogenesis of tooth cusps and the secretion of dental enamel.

  9. The Role of p38 MAPK in the Aetiopathogenesis of Psoriasis and Psoriatic Arthritis

    PubMed Central

    Mavropoulos, Athanasios; Rigopoulou, Eirini I.; Liaskos, Christos; Bogdanos, Dimitrios P.; Sakkas, Lazaros I.

    2013-01-01

    The pathogenetic mechanisms responsible for the induction of immune-mediated disorders, such as psoriasis, remain not well characterized. Molecular signaling pathways are not well described in psoriasis, as well as psoriatic arthritis, which is seen in up to 40% of patients with psoriasis. Signaling pathway defects have long been hypothesized to participate in the pathology of psoriasis, yet their implication in the altered psoriatic gene expression still remains unclear. Emerging data suggest a potential pathogenic role for mitogen activated protein kinases p38 (p38 MAPK) extracellular signal-regulated kinase 1/2 (ERK1/2), and c-Jun N-terminal kinase (JNK) in the development of psoriasis. The data are still limited, though, for psoriatic arthritis. This review discusses the current data suggesting a crucial role for p38 MAPK in the pathogenesis of these disorders. PMID:24151518

  10. A cell-death-defying factor, anamorsin mediates cell growth through inactivation of PKC and p38MAPK

    SciTech Connect

    Saito, Yuri; Shibayama, Hirohiko; Tanaka, Hirokazu; Tanimura, Akira; Kanakura, Yuzuru

    2011-02-11

    Research highlights: {yields} Anamorsin (AM) (also called CIAPIN-1) is a cell-death-defying factor. {yields} Biological mechanisms of AM functions have not been elucidated yet. {yields} PKC{theta} , PKC{delta} and p38MAPK were more phosphorylated in AM deficient MEF cells. {yields} AM may negatively regulates PKCs and p38MAPK in MEF cells. -- Abstract: Anamorsin (AM) plays crucial roles in hematopoiesis and embryogenesis. AM deficient (AM KO) mice die during late gestation; AM KO embryos are anemic and very small compared to wild type (WT) embryos. To determine which signaling pathways AM utilizes for these functions, we used murine embryonic fibroblast (MEF) cells generated from E-14.5 AM KO or WT embryos. Proliferation of AM KO MEF cells was markedly retarded, and PKC{theta}, PKC{delta}, and p38MAPK were more highly phosphorylated in AM KO MEF cells. Expression of cyclinD1, the target molecule of p38MAPK, was down-regulated in AM KO MEF cells. p38MAPK inhibitor as well as PKC inhibitor restored expression of cyclinD1 and cell growth in AM KO MEF cells. These data suggest that PKC{theta}, PKC{delta}, and p38MAPK activation lead to cell cycle retardation in AM KO MEF cells, and that AM may negatively regulate novel PKCs and p38MAPK in MEF cells.

  11. Antagonistic control of cell fates by JNK and p38-MAPK signaling.

    PubMed

    Wada, T; Stepniak, E; Hui, L; Leibbrandt, A; Katada, T; Nishina, H; Wagner, E F; Penninger, J M

    2008-01-01

    During the development and organogenesis of all multicellular organisms, cell fate decisions determine whether cells undergo proliferation, differentiation, or aging. Two independent stress kinase signaling pathways, p38-MAPK, and JNKs, have evolved that relay developmental and environmental cues to determine cell responses. Although multiple stimuli can activate these two stress kinase pathways, the functional interactions and molecular cross-talks between these common second signaling cascades are poorly elucidated. Here we report that JNK and p38-MAPK pathways antagonistically control cellular senescence, oncogenic transformation, and proliferation in primary mouse embryonic fibroblasts (MEFs). Similarly, genetic inactivation of the JNK pathway results in impaired proliferation of fetal hepatoblasts in vitro and defective adult liver regeneration in vivo, which is rescued by inhibition of the p38-MAPK pathway. Thus, the balance between the two stress-signaling pathways, MKK7-JNK and MKK3/6-p38-MAPK, determines cell fate and links environmental and developmental stress to cell cycle arrest, senescence, oncogenic transformation, and adult tissue regeneration. PMID:17762881

  12. Hyperhomocysteinemia inhibits satellite cell regenerative capacity through p38 alpha/beta MAPK signaling.

    PubMed

    Veeranki, Sudhakar; Lominadze, David; Tyagi, Suresh C

    2015-07-15

    Chronic failure in maintenance and regeneration of skeletal muscles leads to lower muscle mass (sarcopenia), muscle weakness, and poor response to injury. Evidence suggests that aberrant p38 MAPK signaling undermines the repair process after injury in aged mice. Previous studies have shown that hyperhomocysteinemia (HHcy) has been associated with muscle weakness and lower than normal body weights. However, whether or not HHcy condition also compromises skeletal muscle regenerative capabilities is not clear. In the current study, we show that CBS-/+ mice, a model for HHcy condition, exhibited compromised regenerative function and cell proliferation upon injury. However, there was no significant difference in Pax7 expression levels in the satellite cells from CBS-/+ mouse skeletal muscles. Interestingly, the satellite cells from CBS-/+ mice not only exhibited diminished in vitro proliferative capabilities, but also there was heightened oxidative stress. In addition, there was enhanced p38 MAPK activation as well as p16 and p21 expression in the CBS-/+ mouse satellite cells. Moreover, the C2C12 myoblasts also exhibited higher p38 MAPK activation and p16 expression upon treatment with homocysteine in addition to enhanced ROS presence. Tissue engraftment potential and regeneration after injury were restored to some extent upon treatment with the p38-MAPK inhibitor, SB203580, in the CBS-/+ mice. These results together suggest that HHcy-induced diminished satellite cell proliferation involves excessive oxidative stress and p38 MAPK signaling. Our study further proposes that HHcy is a potential risk factor for elderly frailty, and need to be considered as a therapeutic target while designing the alleviation interventions/postinjury rehabilitation measures for adults with HHcy.

  13. Novel human neutrophil agonistic properties of arsenic trioxide: involvement of p38 mitogen-activated protein kinase and/or c-jun NH2-terminal MAPK but not extracellular signal-regulated kinases-1/2.

    PubMed

    Binet, François; Girard, Denis

    2008-12-01

    Arsenic trioxide (ATO) is known for treating acute promyelocytic leukemia and for inducing apoptosis and mitogen-activated protein kinases (MAPKs) in promyelocytes and cancer cells. We recently reported that ATO induces neutrophil apoptosis. The aim of this study was to establish whether or not ATO recruits MAPKs in neutrophils, as well as to further investigate its agonistic properties. We found that ATO activates p38 and that, unlike H2O2, this response was not inhibited by exogenous catalase. Also, we demonstrated that ATO-induced p38 activation occurs before H2O2 generation and without a calcium burst. We next established that ATO recruits c-jun NH2-terminal (JNK) but not extracellular signal-regulated kinase 1 and 2 (Erk-1/2). Using pharmacological inhibitors, we found that the proapoptotic activity of ATO occurs by a MAPK-independent mechanism. In contrast, the ability of ATO to enhance adhesion, migration, phagocytosis, release, and activity of gelatinase and degranulation of secretory, specific, and gelatinase, but not azurophilic granules, is dependent upon activation of p38 and/or JNK. This is the first study establishing that ATO possesses important agonistic properties in human neutrophils. Given the central role of neutrophils in various inflammatory disorders, we propose that ATO might have broader therapeutic implications in clinics, especially for regulating inflammation.

  14. [Insulin combined with selenium inhibit p38MAPK/CBP pathway and suppresses cardiomyocyte apoptosis in rats with diabetic cardiomyopathy].

    PubMed

    Xu, Tianjiao; Liu, Yong; Deng, Yating; Meng, Jin; Li, Ping; Xu, Xiaoli; Zeng, Jurong

    2016-07-01

    Objective To investigate the effect of insulin in combination with selenium on p38-mitogen-activated protein kinase/CREB-binding protein (p38MAPK/CBP) pathway in rats with diabetic cardiomyopathy. Methods Fifty SD rats were randomly grouped into control group, diabetic cardiomyopathy (DCM) group, diabetic cardiomyopathy with insulin treatment (DCM-In) group, diabetic cardiomyopathy with selenium treatment (DCM-Se) group, and diabetic cardiomyopathy with insulin and selenium combination treatment (DCM-In-Se) group. Flow cytometry was used to analyze cell cycle. TUNEL staining was used to detect cardiomyocyte apoptosis. Western blotting was used to examine the levels of cyclin D1, cyclin E, Bax, Bcl-2, p38MAPK, p-p38MAPK, CBP and Ku70. Co-immunoprecipitation was used to examine the acetylation status of Ku70. Results Insulin in combination with selenium significantly inhibited cardiomyocyte apoptosis, increased Bcl-2 levels and decreased Bax, cyclin D1, cyclin E, p38MAPK, p-p38MAPK, CBP, Ku70 and acetylated Ku70 levels. Conclusion The combined treatment of insulin and selenium suppresses cardiomyocyte apoptosis by inhibiting p38MAPK/CBP pathway. PMID:27363274

  15. Fisetin Inhibits Migration and Invasion of Human Cervical Cancer Cells by Down-Regulating Urokinase Plasminogen Activator Expression through Suppressing the p38 MAPK-Dependent NF-κB Signaling Pathway

    PubMed Central

    Chou, Ruey-Hwang; Hsieh, Shu-Ching; Yu, Yung-Luen; Huang, Min-Hsien; Huang, Yi-Chang; Hsieh, Yi-Hsien

    2013-01-01

    Fisetin (3,3’,4’,7-tetrahydroxyflavone), a naturally occurring flavonoid, has been reported to inhibit proliferation and induce apoptosis in several cancer types. However, its effect on the anti-metastatic potential of cervical cancer cells remains unclear. In the present study, we found that fisetin inhibits the invasion and migration of cervical cancer cells. The expression and activity of urokinase plasminogen activator (uPA) was significantly suppressed by fisetin in a dose-dependent manner. We also demonstrated that fisetin reduces the phosphorylation of p38 MAPK, but not that of ERK1/2, JNK1/2, or AKT. Addition of a p38 MAPK inhibitor, SB203580, further enhanced the inhibitory effect of fisetin on the expression and activity of uPA and the invasion and motility in cervical cancer cells. Fisetin suppressed the TPA (tetradecanoylphorbol-13-acetate)-induced activation of p38 MAPK and uPA, and inhibited the TPA-enhanced migratory and invasive abilities. Furthermore, the promoter activity of the uPA gene was dramatically repressed by fisetin, which disrupted the nuclear translocation of NF-κB and its binding amount on the promoter of the uPA gene, and these suppressive effects could be further enhanced by SB203580. This study provides strong evidence for the molecular mechanism of fisetin in inhibiting the aggressive phenotypes by repression of uPA via interruption of p38 MAPK-dependent NF-κB signaling pathway in cervical cancer cells and thus contributes insight to the potential of using fisetin as a therapeutic strategy against cervical cancer by inhibiting migration and invasion. PMID:23940799

  16. Fisetin inhibits migration and invasion of human cervical cancer cells by down-regulating urokinase plasminogen activator expression through suppressing the p38 MAPK-dependent NF-κB signaling pathway.

    PubMed

    Chou, Ruey-Hwang; Hsieh, Shu-Ching; Yu, Yung-Luen; Huang, Min-Hsien; Huang, Yi-Chang; Hsieh, Yi-Hsien

    2013-01-01

    Fisetin (3,3',4',7-tetrahydroxyflavone), a naturally occurring flavonoid, has been reported to inhibit proliferation and induce apoptosis in several cancer types. However, its effect on the anti-metastatic potential of cervical cancer cells remains unclear. In the present study, we found that fisetin inhibits the invasion and migration of cervical cancer cells. The expression and activity of urokinase plasminogen activator (uPA) was significantly suppressed by fisetin in a dose-dependent manner. We also demonstrated that fisetin reduces the phosphorylation of p38 MAPK, but not that of ERK1/2, JNK1/2, or AKT. Addition of a p38 MAPK inhibitor, SB203580, further enhanced the inhibitory effect of fisetin on the expression and activity of uPA and the invasion and motility in cervical cancer cells. Fisetin suppressed the TPA (tetradecanoylphorbol-13-acetate)-induced activation of p38 MAPK and uPA, and inhibited the TPA-enhanced migratory and invasive abilities. Furthermore, the promoter activity of the uPA gene was dramatically repressed by fisetin, which disrupted the nuclear translocation of NF-κB and its binding amount on the promoter of the uPA gene, and these suppressive effects could be further enhanced by SB203580. This study provides strong evidence for the molecular mechanism of fisetin in inhibiting the aggressive phenotypes by repression of uPA via interruption of p38 MAPK-dependent NF-κB signaling pathway in cervical cancer cells and thus contributes insight to the potential of using fisetin as a therapeutic strategy against cervical cancer by inhibiting migration and invasion.

  17. A novel p38 MAPK docking groove-targeted compound is a potent inhibitor of inflammatory hyperalgesia

    PubMed Central

    Willemen, Hanneke L.D.M.; Campos, Pedro M.; Lucas, Elisa; Morreale, Antonio; Gil-Redondo, Rubén; Agut, Juan; González, Florenci V.; Ramos, Paula; Heijnen, Cobi; Mayor, Federico; Kavelaars, Annemieke; Murga, Cristina

    2014-01-01

    Synopsis The mitogen activated protein kinase (MAPK) p38 is an important mediator of inflammation and of inflammatory and neuropathic pain. We recently described that docking-groove dependent interactions are important for p38 MAPK-mediated signal transduction. Thus, virtual screening was performed to identify putative docking groove-targeted p38 MAPK inhibitors. Several compounds of the benzooxadiazol family were identified with low micromolar inhibitory activity both in a p38 MAPK activity assay, and in THP-1 human monocytes acting as inhibitors of LPS-induced TNFα secretion. Positions 2 and 5 in the phenyl ring are essential for the described inhibitory activity with a chloride in position 5 and a methyl-group in position 2 yielding the best results with an IC50 of 1.8 μM (FGA-19 compound). Notably, FGA-19 exerted a potent and long-lasting analgesic effect in vivo when tested in a mouse model of inflammatory hyperalgesia. A single intrathecal injection of FGA-19 completely resolved hyperalgesia, being ten times as potent and displaying longer lasting effects than the established p38 MAPK inhibitor SB239063. FGA-19 also reversed persistent pain in a model of post-inflammatory hyperalgesia (in LysM-GRK2+/− mice). These potent in vivo effects put forward p38 MAPK docking-site targeted inhibitors as a potential novel strategy for the treatment of inflammatory pain. PMID:24517375

  18. Cyclooxygenase-2 is induced by p38 MAPK and promotes cell survival.

    PubMed

    Parente, Rosanna; Trifirò, Elisabetta; Cuozzo, Francesca; Valia, Sandro; Cirone, Mara; Di Renzo, Livia

    2013-05-01

    The Na+ ionophore monensin affects cellular pH and, depending on its concentration, causes the survival or death of tumor cells. In the present study, we elucidated the survival pathway activated in U937 cells, a human lymphoma-derived cell line. These cells treated with monensin at a concentration of 5 µM were growth-arrested in G1, activated p38 mitogen-activated protein kinase (MAPK) and showed an increased expression of cyclooxygenase-2 (COX-2). The latter two molecular events were linked, as pharmacological inhibition of the MAPK did not allow COX-2 increased expression. Furthermore, we showed that p38 and COX-2 keep monensin-stressed U937 cells alive, as pharmacological inhibition of each enzyme caused cell death. PMID:23446663

  19. Advanced Glycation End Products Impair Glucose-Stimulated Insulin Secretion of a Pancreatic β-Cell Line INS-1-3 by Disturbance of Microtubule Cytoskeleton via p38/MAPK Activation.

    PubMed

    You, Jia; Wang, Zai; Xu, Shiqing; Zhang, Wenjian; Fang, Qing; Liu, Honglin; Peng, Liang; Deng, Tingting; Lou, Jinning

    2016-01-01

    Advanced glycation end products (AGEs) are believed to be involved in diverse complications of diabetes mellitus. Overexposure to AGEs of pancreatic β-cells leads to decreased insulin secretion and cell apoptosis. Here, to understand the cytotoxicity of AGEs to pancreatic β-cells, we used INS-1-3 cells as a β-cell model to address this question, which was a subclone of INS-1 cells and exhibited high level of insulin expression and high sensitivity to glucose stimulation. Exposed to large dose of AGEs, even though more insulin was synthesized, its secretion was significantly reduced from INS-1-3 cells. Further, AGEs treatment led to a time-dependent increase of depolymerized microtubules, which was accompanied by an increase of activated p38/MAPK in INS-1-3 cells. Pharmacological inhibition of p38/MAPK by SB202190 reversed microtubule depolymerization to a stabilized polymerization status but could not rescue the reduction of insulin release caused by AGEs. Taken together, these results suggest a novel role of AGEs-induced impairment of insulin secretion, which is partially due to a disturbance of microtubule dynamics that resulted from an activation of the p38/MAPK pathway. PMID:27635403

  20. Advanced Glycation End Products Impair Glucose-Stimulated Insulin Secretion of a Pancreatic β-Cell Line INS-1-3 by Disturbance of Microtubule Cytoskeleton via p38/MAPK Activation

    PubMed Central

    You, Jia; Xu, Shiqing; Zhang, Wenjian; Fang, Qing; Liu, Honglin; Peng, Liang; Deng, Tingting

    2016-01-01

    Advanced glycation end products (AGEs) are believed to be involved in diverse complications of diabetes mellitus. Overexposure to AGEs of pancreatic β-cells leads to decreased insulin secretion and cell apoptosis. Here, to understand the cytotoxicity of AGEs to pancreatic β-cells, we used INS-1-3 cells as a β-cell model to address this question, which was a subclone of INS-1 cells and exhibited high level of insulin expression and high sensitivity to glucose stimulation. Exposed to large dose of AGEs, even though more insulin was synthesized, its secretion was significantly reduced from INS-1-3 cells. Further, AGEs treatment led to a time-dependent increase of depolymerized microtubules, which was accompanied by an increase of activated p38/MAPK in INS-1-3 cells. Pharmacological inhibition of p38/MAPK by SB202190 reversed microtubule depolymerization to a stabilized polymerization status but could not rescue the reduction of insulin release caused by AGEs. Taken together, these results suggest a novel role of AGEs-induced impairment of insulin secretion, which is partially due to a disturbance of microtubule dynamics that resulted from an activation of the p38/MAPK pathway.

  1. Advanced Glycation End Products Impair Glucose-Stimulated Insulin Secretion of a Pancreatic β-Cell Line INS-1-3 by Disturbance of Microtubule Cytoskeleton via p38/MAPK Activation

    PubMed Central

    You, Jia; Xu, Shiqing; Zhang, Wenjian; Fang, Qing; Liu, Honglin; Peng, Liang; Deng, Tingting

    2016-01-01

    Advanced glycation end products (AGEs) are believed to be involved in diverse complications of diabetes mellitus. Overexposure to AGEs of pancreatic β-cells leads to decreased insulin secretion and cell apoptosis. Here, to understand the cytotoxicity of AGEs to pancreatic β-cells, we used INS-1-3 cells as a β-cell model to address this question, which was a subclone of INS-1 cells and exhibited high level of insulin expression and high sensitivity to glucose stimulation. Exposed to large dose of AGEs, even though more insulin was synthesized, its secretion was significantly reduced from INS-1-3 cells. Further, AGEs treatment led to a time-dependent increase of depolymerized microtubules, which was accompanied by an increase of activated p38/MAPK in INS-1-3 cells. Pharmacological inhibition of p38/MAPK by SB202190 reversed microtubule depolymerization to a stabilized polymerization status but could not rescue the reduction of insulin release caused by AGEs. Taken together, these results suggest a novel role of AGEs-induced impairment of insulin secretion, which is partially due to a disturbance of microtubule dynamics that resulted from an activation of the p38/MAPK pathway. PMID:27635403

  2. Targeted inhibition of p38MAPK-enhanced autophagy in SW620 cells resistant to photodynamic therapy-induced apoptosis.

    PubMed

    Xue, Qin; Wang, Pan; Wang, Xiaobing; Zhang, Kun; Liu, Quanhong

    2015-09-01

    Photodynamic therapy (PDT) is a promising and noninvasive treatment that can induce apoptosis, autophagy, or both depending on the cell phenotype. In this work, chlorin e6 (Ce6) was used to photosensitize human colorectal cancer SW620 cells. In cells, apparent autophagy and apoptosis with dependence on intracellular reactive oxygen species (ROS) generation were detected. p38MAPK activation followed by ROS generation might be a core component in Ce6 mediate PDT (Ce6-PDT)-induced autophagy and apoptosis signaling pathway. By using p38MAPK siRNA, the results showed a marked enhancement on cell apoptosis in Ce6-PDT with increased annexin (+) apoptotic cells, nuclear condensation, caspase-3, and PARP cleavage. Besides, impairment of p38MAPK also promoted the autophagic response to photodamage as indicated by conversion of LC3 and monodansyl cadaverine (MDC) labeling patterns. It appears that Ce6-PDT induced ROS production involving activation of p38MAPK, probably to prevent SW620 cells from photodamage. Moreover, autophagy inhibitor 3-methyladenine/bafilomycin A1 greatly aggravated Ce6-PDT-induced apoptosis in SW620 cells with knockdown of p38MAPK. Taken together, this study suggests that autophagy could represent a promising field in cancer treatment and p38MAPK may be a potential therapeutic target to enhance the efficacy on clinical evaluation for the treatment of colorectal cancer. PMID:26254783

  3. Porcine circovirus type 2 activates PI3K/Akt and p38 MAPK pathways to promote interleukin-10 production in macrophages via Cap interaction of gC1qR

    PubMed Central

    Wang, Tongtong; Zhang, Xiujuan; Chen, Yu; Cui, Beibei; Li, Delong; Zhao, Xiaomin; Zhang, Wenlong; Chang, Lingling; Tong, Dewen

    2016-01-01

    Porcine circovirus type 2 (PCV2) infection caused PCV2-associated diseases (PCVAD) is one of the major emerging immunosuppression diseases in pig industry. In this study, we investigated how PCV2 inoculation increases interleukin (IL)-10 expression in porcine alveolar macrophages (PAMs). PCV2 inoculation significantly upregulated IL-10 expression compared with PCV1. Upon initial PCV2 inoculation, PI3K/Akt cooperated with NF-κB pathways to promote IL-10 transcription via p50, CREB and Ap1 transcription factors, whereas inhibition of PI3K/Akt activation blocked Ap1 and CREB binding to the il10 promoter, and decreased the binding level of NF-κB1 p50 with il10 promoter, leading to great reduction in early IL-10 transcription. In the later phase of inoculation, PCV2 further activated p38 MAPK and ERK pathways to enhance IL-10 production by promoting Sp1 binding to the il10 promoter. For PCV2-induced IL-10 production in macrophages, PCV2 capsid protein Cap, but not the replicase Rep or ORF3, was the critical component. Cap activated PI3K/Akt, p38 MAPK, and ERK signaling pathways to enhance IL-10 expression. In the whole process, gC1qR mediated PCV2-induced PI3K/Akt and p38 MAPK activation to enhance IL-10 induction by interaction with Cap. Depletion of gC1qR blocked PI3K/Akt and p38 MAPK activation, resulting in significant decrease in IL-10 production in PCV2-inoculated cells. Thus, gC1qR might be a critical functional receptor for PCV2-induced IL-10 production. Taken together, these data demonstrated that Cap protein binding with host gC1qR induction of PI3K/Akt and p38 MAPK signalings activation is a critical process in enhancing PCV2-induced IL-10 production in porcine alveolar macrophages. PMID:26883107

  4. Porcine circovirus type 2 activates PI3K/Akt and p38 MAPK pathways to promote interleukin-10 production in macrophages via Cap interaction of gC1qR.

    PubMed

    Du, Qian; Huang, Yong; Wang, Tongtong; Zhang, Xiujuan; Chen, Yu; Cui, Beibei; Li, Delong; Zhao, Xiaomin; Zhang, Wenlong; Chang, Lingling; Tong, Dewen

    2016-04-01

    Porcine circovirus type 2 (PCV2) infection caused PCV2-associated diseases (PCVAD) is one of the major emerging immunosuppression diseases in pig industry. In this study, we investigated how PCV2 inoculation increases interleukin (IL)-10 expression in porcine alveolar macrophages (PAMs). PCV2 inoculation significantly upregulated IL-10 expression compared with PCV1. Upon initial PCV2 inoculation, PI3K/Akt cooperated with NF-κB pathways to promote IL-10 transcription via p50, CREB and Ap1 transcription factors, whereas inhibition of PI3K/Akt activation blocked Ap1 and CREB binding to the il10 promoter, and decreased the binding level of NF-κB1 p50 with il10 promoter, leading to great reduction in early IL-10 transcription. In the later phase of inoculation, PCV2 further activated p38 MAPK and ERK pathways to enhance IL-10 production by promoting Sp1 binding to the il10 promoter. For PCV2-induced IL-10 production in macrophages, PCV2 capsid protein Cap, but not the replicase Rep or ORF3, was the critical component. Cap activated PI3K/Akt, p38 MAPK, and ERK signaling pathways to enhance IL-10 expression. In the whole process, gC1qR mediated PCV2-induced PI3K/Akt and p38 MAPK activation to enhance IL-10 induction by interaction with Cap. Depletion of gC1qR blocked PI3K/Akt and p38 MAPK activation, resulting in significant decrease in IL-10 production in PCV2-inoculated cells. Thus, gC1qR might be a critical functional receptor for PCV2-induced IL-10 production. Taken together, these data demonstrated that Cap protein binding with host gC1qR induction of PI3K/Akt and p38 MAPK signalings activation is a critical process in enhancing PCV2-induced IL-10 production in porcine alveolar macrophages. PMID:26883107

  5. Tumor Necrosis Factor-Like Weak Inducer of Apoptosis Accelerates the Progression of Renal Fibrosis in Lupus Nephritis by Activating SMAD and p38 MAPK in TGF-β1 Signaling Pathway

    PubMed Central

    Liu, Zhiqin; Xue, Leixi; Liu, Zhichun; Huang, Jun; Wen, Jian; Hu, Ji; Bo, Lin; Yang, Ru

    2016-01-01

    This study aim was to explore the effects of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in lupus nephritis and its potential underlying mechanisms. MRL/lpr mice were used for in vivo experiments and human proximal tubular cells (HK2 cells) were used for in vitro experiments. Results showed that MRL/lpr mice treated with vehicle solution or LV-Control shRNA displayed significant proteinuria and severe renal histopathological changes. LV-TWEAK-shRNA treatment reversed these changes and decreased renal expressions of TWEAK, TGF-β1, p-p38 MAPK, p-Smad2, COL-1, and α-SMA proteins. In vitro, hTWEAK treatment upregulated the expressions of TGF-β1, p-p38 MAPK, p-SMAD2, α-SMA, and COL-1 proteins in HK2 cells and downregulated the expressions of E-cadherin protein, which were reversed by cotreatment with anti-TWEAK mAb or SB431542 treatment. These findings suggest that TWEAK may contribute to chronic renal changes and renal fibrosis by activating TGF-β1 signaling pathway, and phosphorylation of Smad2 and p38 MAPK proteins was also involved in this signaling pathway. PMID:27365897

  6. Curcumin exerts antitumor effects in retinoblastoma cells by regulating the JNK and p38 MAPK pathways.

    PubMed

    Yu, Xiaoming; Zhong, Jingtao; Yan, Li; Li, Jie; Wang, Hui; Wen, Yan; Zhao, Yu

    2016-09-01

    Curcumin, a naturally occurring polyphenolic compound present in turmeric (Curcuma longa), exerts antitumor effects in various types of malignancy. However, the precise mechanisms responsible for the effects of curcumin on retinoblastoma (RB) cells have not been fully explored. In the present study, the molecular mechanisms by which curcumin exerts its anticancer effects in RB Y79 cells were investigated. The results showed that curcumin reduced cell viability in Y79 cells. Curcumin induced G1 phase arrest through downregulating the expression of cyclin D3 and cyclin-dependent kinase (CDK)2/6 and upregulating the expression of CDK inhibitor proteins p21 and p27. Curcumin-induced apoptosis of Y79 cells occurred through the activation of caspases-9/-3. Moreover, flow cytometric analysis showed that curcumin induced mitochondrial membrane potential (∆Ψm) collapse in Y79 cells. We also found that curcumin induced the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). JNK and p38 MAPK inhibitors significantly suppressed curcumin‑induced activation of caspases-9/-3 and inhibited the apoptosis of Y79 cells. Taken together, our results suggest that curcumin induced the apoptosis of Y79 cells through the activation of JNK and p38 MAPK pathways. These findings provide a novel treatment strategy for human RB. PMID:27432244

  7. A role for p38 mitogen-activated protein kinase in early post-embryonic development of Schistosoma mansoni.

    PubMed

    Ressurreição, Margarida; Rollinson, David; Emery, Aidan M; Walker, Anthony J

    2011-11-01

    The importance of p38 mitogen-activated protein kinase (p38 MAPK) to Schistosoma mansoni miracidium to mother-sporocyst development was investigated. Western blotting revealed that phosphorylation (activation) of p38 MAPK was low in larvae after 4h development in vitro but increased markedly during transformation, with ∼2.7- and ∼3.7-fold increases after 19h and 28h culture, respectively. Immunohistochemistry of larvae undergoing transformation revealed activated p38 MAPK associated with regions including the tegument, neural mass and germinal cells. Inhibition of larval p38 MAPK with SB203580 reduced significantly the rate of development of miracidia to mother sporocysts, whereas activation of p38 MAPK with anisomycin had the opposite effect. These results provide insight into p38 MAPK signalling in schistosomes and support a role for p38 MAPK in the early post-embryonic development of S. mansoni. PMID:21787807

  8. E2F1 modulates p38 MAPK phosphorylation via transcriptional regulation of ASK1 and Wip1.

    PubMed

    Hershko, Tzippi; Korotayev, Katya; Polager, Shirley; Ginsberg, Doron

    2006-10-20

    The E2F family of transcription factors regulates a diverse array of cellular functions, including cell proliferation, cell differentiation, and apoptosis. Recent studies indicate that E2F can also regulate transcription of upstream components of signal transduction pathways. We show here that E2F1 modulates the activity of the p38 MAPK pathway via E2F1-induced transient up-regulation of p38 MAPK phosphorylation. The mechanism by which E2F1 modulates p38 MAPK phosphorylation involves transcriptional induction of the kinase ASK1, a member of the MAPKKK family that phosphorylates p38 MKKs. Subsequent E2F-dependent down-regulation of the p38 signaling pathway is achieved through E2F-induced up-regulation of Wip1, a phosphatase that dephosphorylates and inactivates p38. Both ASK1 and Wip1 are essential mediators of the E2F-p38 connection: knock down of ASK1 inhibits E2F1-induced phosphorylation of p38, whereas knock down of Wip1 prolongs E2F1-induced p38 phosphorylation. Furthermore, Wip1 knock down enhances E2F1-induced apoptosis. Therefore, our data reveal a novel link between a central signaling pathway and the transcription factor E2F and identify Wip1 as a modulator of E2F1-induced apoptosis. PMID:16912047

  9. Vandetanib combined with a p38 MAPK inhibitor synergistically reduces glioblastoma cell survival.

    PubMed

    Sooman, Linda; Lennartsson, Johan; Gullbo, Joachim; Bergqvist, Michael; Tsakonas, Georgios; Johansson, Fredrik; Edqvist, Per-Henrik; Pontén, Fredrik; Jaiswal, Archita; Navani, Sanjay; Alafuzoff, Irina; Popova, Svetlana; Blomquist, Erik; Ekman, Simon

    2013-01-01

    The survival for patients with high-grade glioma is poor, and only a limited number of patients respond to the therapy. The aim of this study was to analyze the significance of using p38 MAPK phosphorylation as a prognostic marker in high-grade glioma patients and as a therapeutic target in combination chemotherapy with vandetanib. p38 MAPK phosphorylation was analyzed with immunohistochemistry in 90 high-grade glioma patients. Correlation between p38 MAPK phosphorylation and overall survival was analyzed with Mann-Whitney U test analysis. The effects on survival of glioblastoma cells of combining vandetanib with the p38 MAPK inhibitor SB 203580 were analyzed in vitro with the median-effect method with the fluorometric microculture cytotoxicity assay. Two patients had phosphorylated p38 MAPK in both the cytoplasm and nucleus, and these two presented with worse survival than patients with no detectable p38 MAPK phosphorylation or phosphorylated p38 MAPK only in the nucleus. This was true for both high-grade glioma patients (WHO grade III and IV, n = 90, difference in median survival: 6.1 months, 95 % CI [0.20, 23], p = 0.039) and for the subgroup with glioblastoma patients (WHO grade IV, n = 70, difference in median survival: 6.1 months, 95 % CI [0.066, 23], p = 0.043). The combination of vandetanib and the p38 MAPK inhibitor SB 203580 had synergistic effects on cell survival for glioblastoma-derived cells in vitro. In conclusion, p38 MAPK phosphorylation may be a prognostic marker for high-grade glioma patients, and vandetanib combined with a p38 MAPK inhibitor may be useful combination chemotherapy for glioma patients. PMID:23783486

  10. Heat stress prevents lipopolysaccharide-induced apoptosis in pulmonary microvascular endothelial cells by blocking calpain/p38 MAPK signalling

    PubMed Central

    Liu, Zhi-feng; Zheng, Dong; Fan, Guo-chang; Peng, Tianqing; Su, Lei

    2016-01-01

    Pulmonary microvascular endothelial cells (PMECs) injury including apoptosis plays an important role in the pathogenesis of acute lung injury during sepsis. Our recent study has demonstrated that calpain activation contributes to apoptosis in PMECs under septic conditions. This study investigated how calpain activation mediated apoptosis and whether heat stress regulated calpain activation in lipopolysaccharides (LPS)-stimulated PMECs. In cultured mouse primary PMECs, incubation with LPS (1 µg/ml, 24 h) increased active caspase-3 fragments and DNA fragmentation, indicative of apoptosis. These effects of LPS were abrogated by pre-treatment with heat stress (43 °C for 2 h). LPS also induced calpain activation and increased phosphorylation of p38 MAPK. Inhibition of calpain and p38 MAPK prevented apoptosis induced by LPS. Furthermore, inhibition of calpain blocked p38 MAPK phosphorylation in LPS-stimulated PMECs. Notably, heat stress decreased the protein levels of calpain-1/2 and calpain activities, and blocked p38 MAPK phosphorylation in response to LPS. Additionally, forced up-regulation of calpain-1 or calpain-2 sufficiently induced p38 MAPK phosphorylation and apoptosis in PMECs, both of which were inhibited by heat stress. In conclusion, heat stress prevents LPS-induced apoptosis in PMECs. This effect of heat stress is associated with down-regulation of calpain expression and activation, and subsequent blockage of p38 MAPK activation in response to LPS. Thus, blocking calpain/p38 MAPK pathway may be a novel mechanism underlying heat stress-mediated inhibition of apoptosis in LPS-stimulated endothelial cells. PMID:27325431

  11. Hypoxia Drives Breast Tumor Malignancy through a TET-TNFα-p38-MAPK Signaling Axis.

    PubMed

    Wu, Min-Zu; Chen, Su-Feng; Nieh, Shin; Benner, Christopher; Ger, Luo-Ping; Jan, Chia-Ing; Ma, Li; Chen, Chien-Hung; Hishida, Tomoaki; Chang, Hong-Tai; Lin, Yaoh-Shiang; Montserrat, Nuria; Gascon, Pedro; Sancho-Martinez, Ignacio; Izpisua Belmonte, Juan Carlos

    2015-09-15

    Hypoxia is a hallmark of solid tumors that drives malignant progression by altering epigenetic controls. In breast tumors, aberrant DNA methylation is a prevalent epigenetic feature associated with increased risk of metastasis and poor prognosis. However, the mechanism by which hypoxia alters DNA methylation or other epigenetic controls that promote breast malignancy remains poorly understood. We discovered that hypoxia deregulates TET1 and TET3, the enzymes that catalyze conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), thereby leading to breast tumor-initiating cell (BTIC) properties. TET1/3 and 5hmC levels were closely associated with tumor hypoxia, tumor malignancy, and poor prognosis in breast cancer patients. Mechanistic investigations showed that hypoxia leads to genome-wide changes in DNA hydroxymethylation associated with upregulation of TNFα expression and activation of its downstream p38-MAPK effector pathway. Coordinate functions of TET1 and TET3 were also required to activate TNFα-p38-MAPK signaling as a response to hypoxia. Our results reveal how signal transduction through the TET-TNFα-p38-MAPK signaling axis is required for the acquisition of BTIC characteristics and tumorigenicity in vitro and in vivo, with potential implications for how to eradicate BTIC as a therapeutic strategy. PMID:26294212

  12. p38MAPK inhibition: a new combined approach to reduce neuroblastoma resistance under etoposide treatment

    PubMed Central

    Marengo, B; De Ciucis, C G; Ricciarelli, R; Furfaro, A L; Colla, R; Canepa, E; Traverso, N; Marinari, U M; Pronzato, M A; Domenicotti, C

    2013-01-01

    Neuroblastoma (NB) is the second most common solid pediatric tumor and is characterized by clinical and biological heterogeneity, and stage-IV of the disease represents 50% of all cases. Considering the limited success of present chemotherapy treatment, it has become necessary to find new and effective therapies. In this context, our approach consists of identifying and targeting key molecular pathways associated with NB chemoresistance. This study has been carried out on three stage-IV NB cell lines with different status of MYCN amplification. Cells were exposed to a standard chemotherapy agent, namely etoposide, either alone or in combination with particular drugs, which target intracellular signaling pathways. Etoposide alone induced a concentration-dependent reduction of cell viability and, at very high doses, totally counteracted cell tumorigenicity and neurosphere formation. In addition, etoposide activated p38 mitogen-activated protein kinase (MAPK), AKT and c-Jun N-terminal kinase. Pre-treatment with SB203580, a p38MAPK inhibitor, dramatically sensibilized NB cells to etoposide, strongly reducing the dosage needed to inhibit tumorigenicity and neurosphere formation. Importantly, SB203580–etoposide cotreatment also reduced cell migration and invasion by affecting cyclooxygenase-2, intercellular adhesion molecule-1, C–X–C chemokine receptor-4 and matrix metalloprotease-9. Collectively, our results suggest that p38MAPK inhibition, in combination with standard chemotherapy, could represent an effective strategy to counteract NB resistance in stage-IV patients. PMID:23579276

  13. p38MAPK and Chemotherapy: We Always Need to Hear Both Sides of the Story

    PubMed Central

    García-Cano, Jesús; Roche, Olga; Cimas, Francisco J.; Pascual-Serra, Raquel; Ortega-Muelas, Marta; Fernández-Aroca, Diego M.; Sánchez-Prieto, Ricardo

    2016-01-01

    The p38MAPK signaling pathway was initially described as a stress response mechanism. In fact, during previous decades, it was considered a pathway with little interest in oncology especially in comparison with other MAPKs such as ERK1/2, known to be target of oncogenes like Ras. However, its involvement in apoptotic cell death phenomena makes this signaling pathway more attractive for many cancer research laboratories. This apoptotic role allows to establish a link between p38MAPK and regular chemotherapeutic agents such as Cisplatin or base analogs (Cytarabine, Gemcitabine or 5-Fluorouracil) which are currently used in hospitals across the world. In fact, and more recently, p38MAPK has also been connected with targeted therapies like tyrosine kinase inhibitors (vg. Imatinib, Sorafenib) and, to a lesser extent, with monoclonal antibodies. In addition, the oncogenic or tumor suppressor potential of this signaling pathway has aroused the interest of the scientific community in evaluating p38MAPK as a novel target for cancer therapy. In this review, we will summarize the role of p38MAPK in chemotherapy as well as the potential that p38MAPK inhibition can bring to cancer therapy. All the evidences suggest that p38MAPK could be a double-edged sword and that the search for the most appropriate candidate patients, depending on their pathology and treatment, will lead to a more rational use of this new therapeutic tool. PMID:27446920

  14. The role of globular heads of the C1q receptor in HPV 16 E2-induced human cervical squamous carcinoma cell apoptosis is associated with p38 MAPK/JNK activation

    PubMed Central

    2013-01-01

    Background Human papillomavirus type 16 (HPV 16) E2 protein is a multifunctional DNA-binding protein. HPV 16 E2 regulates many biological responses, including DNA replication, gene expression, and apoptosis. The purpose of this study was to investigate the relationship among the receptor for globular heads of the human C1q (gC1qR) gene expression, HPV 16 E2 transfection and apoptosis regulation in human cervical squamous carcinoma cells (C33a and SiHa). Methods gC1qR expression was examined in C33a and SiHa cells using real-time PCR and Western blot analysis. Apoptosis of C33a and SiHa cells was assessed by flow cytometry. C33a and SiHa cell viability, migration and proliferation were detected using the water-soluble tetrazolium salt (WST-1) assay, a transwell assay and 3H-thymidine incorporation into DNA (3H-TdR), respectively. Results C33a and SiHa cells that were transfected with a vector encoding HPV 16 E2 displayed significantly increased gC1qR gene expression and p38 mitogen-activated protein kinase (p38 MAPK)/ c-jun N-terminal kinase (JNK) activation as well as up-regulation of cellular apoptosis, which was abrogated by the addition of gC1qR small interfering RNA (siRNA). Furthermore, the changes in C33a and SiHa cell viability, migration and proliferation that were observed upon HPV 16 E2 transfection were abrogated by SB203580 (a p38 MAPK inhibitor) or SP600125 (a JNK inhibitor) treatment. Conclusion These data support a mechanism whereby HPV 16 E2 induces apoptosis by silencing the gC1qR gene or inhibiting p38 MAPK/JNK signalling in cervical squamous cell carcinoma. PMID:23651874

  15. CARMA3 regulates the invasion, migration, and apoptosis of non-small cell lung cancer cells by activating NF-кB and suppressing the P38 MAPK signaling pathway.

    PubMed

    Xia, Z X; Li, Z X; Zhang, M; Sun, L M; Zhang, Q F; Qiu, X S

    2016-04-01

    In our previous study, CARMA3 overexpression in lung cancer cells promoted cell proliferation and invasion; however, the mechanism underlying the role of CARMA3 in cancer cell invasion remained unclear. In the present study, knockdown of CARMA3 in A549 and H1299 cells suppressed cell invasion and migration, and downregulated matrix metalloprotease 9 expression at the protein and mRNA levels, as shown by Western blotting and real-time PCR. CARMA3 knockdown increased cell apoptosis, as shown by flow cytometry, increased the mRNA and protein expression levels of Bax and Caspase3, and downregulated Bcl-2 in A549 and H1299 cells. Phosphorylated P38 levels increased and NF-кB activation decreased following knockdown of CARMA3. SB203580, a P38 MAPK inhibitor, activated NF-кB, increased cell migration, and inhibited cell apoptosis after knockdown of CARMA3 compared to knockdown of CARMA3 without SB203580. These findings indicate that CARMA3 may suppress the activation of the P38 MAPK signaling pathway to regulate invasion, migration and apoptosis of lung cancer cells by activating NF-кB (P65) in the nucleus.

  16. Modulation of inflammation and pathology during dengue virus infection by p38 MAPK inhibitor SB203580.

    PubMed

    Fu, Yilong; Yip, Andy; Seah, Peck Gee; Blasco, Francesca; Shi, Pei-Yong; Hervé, Maxime

    2014-10-01

    Dengue virus (DENV) infection could lead to dengue fever (DF), dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). The disease outcome is controlled by both viral and host factors. Inflammation mediators from DENV-infected cells could contribute to increased vascular permeability, leading to severe DHF/DSS. Therefore, suppression of inflammation could be a potential therapeutic approach for treatment of dengue patients. In this context, p38 MAPK (mitogen-activated protein kinase) is a key enzyme that modulates the initiation of stress and inflammatory responses. Here we show that SB203580, a p38 MAPK inhibitor, suppressed the over production of DENV-induced pro-inflammatory mediators such as TNF-α, IL-8, and RANTES from human PBMCs, monocytic THP-1, and granulocyte KU812 cell lines. Oral administration of SB203580 in DENV-infected AG129 mice prevented hematocrit rise and lymphopenia, limited the development of inflammation and pathology (including intestine leakage), and significantly improved survival. These results, for the first time, have provided experimental evidence to imply that a short term inhibition of p38 MAPK may be beneficial to reduce disease symptoms in dengue patients. PMID:25131378

  17. Modulation of inflammation and pathology during dengue virus infection by p38 MAPK inhibitor SB203580.

    PubMed

    Fu, Yilong; Yip, Andy; Seah, Peck Gee; Blasco, Francesca; Shi, Pei-Yong; Hervé, Maxime

    2014-10-01

    Dengue virus (DENV) infection could lead to dengue fever (DF), dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). The disease outcome is controlled by both viral and host factors. Inflammation mediators from DENV-infected cells could contribute to increased vascular permeability, leading to severe DHF/DSS. Therefore, suppression of inflammation could be a potential therapeutic approach for treatment of dengue patients. In this context, p38 MAPK (mitogen-activated protein kinase) is a key enzyme that modulates the initiation of stress and inflammatory responses. Here we show that SB203580, a p38 MAPK inhibitor, suppressed the over production of DENV-induced pro-inflammatory mediators such as TNF-α, IL-8, and RANTES from human PBMCs, monocytic THP-1, and granulocyte KU812 cell lines. Oral administration of SB203580 in DENV-infected AG129 mice prevented hematocrit rise and lymphopenia, limited the development of inflammation and pathology (including intestine leakage), and significantly improved survival. These results, for the first time, have provided experimental evidence to imply that a short term inhibition of p38 MAPK may be beneficial to reduce disease symptoms in dengue patients.

  18. Cross-talk between NADPH oxidase-PKCα-p(38)MAPK and NF-κB-MT1MMP in activating proMMP-2 by ET-1 in pulmonary artery smooth muscle cells.

    PubMed

    Sarkar, Jaganmay; Chowdhury, Animesh; Chakraborti, Tapati; Chakraborti, Sajal

    2016-04-01

    Treatment of bovine pulmonary artery smooth muscle cells with endothelin-1 (ET-1) caused an increase in the expression and activation of proMMP-2 in the cells. The present study was undertaken to determine the underlying mechanisms involved in this scenario. We demonstrated that (i) pretreatment with NADPH oxidase inhibitor, apocynin; PKC-α inhibitor, Go6976; p(38)MAPK inhibitor SB203580 and NF-κB inhibitor, Bay11-7082 inhibited the expression and activation of proMMP-2 induced by ET-1; (ii) ET-1 treatment to the cells stimulated NADPH oxidase and PKCα activity, p(38)MAPK phosphorylation as well as NF-κB activation by translocation of NF-κBp65 subunit from cytosol to the nucleus, and subsequently by increasing its DNA-binding activity; (iii) ET-1 increases MT1-MMP expression, which was inhibited upon pretreatment with apocynin, Go6976, SB293580, and Bay 11-7082; (iv) ET-1 treatment to the cells downregulated TIMP-2 level. Although apocynin and Go6976 pretreatment reversed ET-1 effect on TIMP-2 level, yet pretreatment of the cells with SB203580 and Bay 11-7082 did not show any discernible change in TIMP-2 level by ET-1. Overall, our results suggest that ET-1-induced activation of proMMP-2 is mediated via cross-talk between NADPH oxidase-PKCα-p(38)MAPK and NFκB-MT1MMP signaling pathways along with a marked decrease in TIMP-2 expression in the cells. PMID:26910780

  19. Cross-talk between NADPH oxidase-PKCα-p(38)MAPK and NF-κB-MT1MMP in activating proMMP-2 by ET-1 in pulmonary artery smooth muscle cells.

    PubMed

    Sarkar, Jaganmay; Chowdhury, Animesh; Chakraborti, Tapati; Chakraborti, Sajal

    2016-04-01

    Treatment of bovine pulmonary artery smooth muscle cells with endothelin-1 (ET-1) caused an increase in the expression and activation of proMMP-2 in the cells. The present study was undertaken to determine the underlying mechanisms involved in this scenario. We demonstrated that (i) pretreatment with NADPH oxidase inhibitor, apocynin; PKC-α inhibitor, Go6976; p(38)MAPK inhibitor SB203580 and NF-κB inhibitor, Bay11-7082 inhibited the expression and activation of proMMP-2 induced by ET-1; (ii) ET-1 treatment to the cells stimulated NADPH oxidase and PKCα activity, p(38)MAPK phosphorylation as well as NF-κB activation by translocation of NF-κBp65 subunit from cytosol to the nucleus, and subsequently by increasing its DNA-binding activity; (iii) ET-1 increases MT1-MMP expression, which was inhibited upon pretreatment with apocynin, Go6976, SB293580, and Bay 11-7082; (iv) ET-1 treatment to the cells downregulated TIMP-2 level. Although apocynin and Go6976 pretreatment reversed ET-1 effect on TIMP-2 level, yet pretreatment of the cells with SB203580 and Bay 11-7082 did not show any discernible change in TIMP-2 level by ET-1. Overall, our results suggest that ET-1-induced activation of proMMP-2 is mediated via cross-talk between NADPH oxidase-PKCα-p(38)MAPK and NFκB-MT1MMP signaling pathways along with a marked decrease in TIMP-2 expression in the cells.

  20. Cobalt oxide nanoparticles induced oxidative stress linked to activation of TNF-α/caspase-8/p38-MAPK signaling in human leukemia cells.

    PubMed

    Chattopadhyay, Sourav; Dash, Sandeep Kumar; Tripathy, Satyajit; Das, Balaram; Kar Mahapatra, Santanu; Pramanik, Panchanan; Roy, Somenath

    2015-06-01

    The purpose of this study was to determine the intracellular signaling transduction pathways involved in oxidative stress induced by nanoparticles in cancer cells. Activation of reactive oxygen species (ROS) has some therapeutic benefits in arresting the growth of cancer cells. Cobalt oxide nanoparticles (CoO NPs) are an interesting compound for oxidative cancer therapy. Our results showed that CoO NPs elicited a significant (P <0.05) amount of ROS in cancer cells. Co-treatment with N-aceyltine cystine (an inhibitor of ROS) had a protective role in cancer cell death induced by CoO NPs. In cultured cells, the elevated level of tumor necrosis factor-alpha (TNF-α) was noted after CoO NPs treatment. This TNF-α persuaded activation of caspase-8 followed by phosphorylation of p38 mitogen-activated protein kinase and induced cell death. This study showed that CoO NPs induced oxidative stress and activated the signaling pathway of TNF-α-Caspase-8-p38-Caspase-3 to cancer cells.

  1. Gulf War illnesses are autoimmune illnesses caused by increased activity of the p38/MAPK pathway in CD4+ immune system cells, which was caused by nerve agent prophylaxis and adrenergic load.

    PubMed

    Moss, J I

    2013-12-01

    Sodium chloride intake might increase the risk for the development of autoimmune diseases by increasing the activity of the p38/MAPK pathway in CD4+ cells thereby producing pathogenic TH17 cells which are inflammatory. Two factors (muscarinic and beta adrenergic stimulation), already shown to potentiate each other's toxic effects in whole mice, and have combined amplified sub lethal effects on mouse T cells, can have the same effect on CD4+ signaling pathways as sodium chloride. Sick 1991 Gulf War veterans express elevated Th17 cytokine activity, and therefore may have autoimmune illnesses caused directly by the above mentioned exposures.

  2. Curcumin I mediates neuroprotective effect through attenuation of quinoprotein formation, p-p38 MAPK expression, and caspase-3 activation in 6-hydroxydopamine treated SH-SY5Y cells.

    PubMed

    Meesarapee, Benjawan; Thampithak, Anusorn; Jaisin, Yamaratee; Sanvarinda, Pimtip; Suksamrarn, Apichart; Tuchinda, Patoomratana; Morales, Noppawan Phumala; Sanvarinda, Yupin

    2014-04-01

    6-Hydroxydopamine (6-OHDA) selectively enters dopaminergic neurons and undergoes auto-oxidation resulting in the generation of reactive oxygen species and dopamine quinones, subsequently leading to apoptosis. This mechanism mimics the pathogenesis of Parkinson's disease and has been used to induce experimental Parkinsonism in both in vitro and in vivo systems. In this study, we investigated the effects of curcumin I (diferuloylmethane) purified from Curcuma longa on quinoprotein production, phosphorylation of p38 MAPK (p-p38), and caspase-3 activation in 6-OHDA-treated SH-SY5Y dopaminergic cells. Pretreatment of SH-SY5Y with curcumin I at concentrations of 1, 5, 10, and 20 μM, significantly decreased the formation of quinoprotein and reduced the levels of p-p38 and cleaved caspase-3 in a dose-dependent manner. Moreover, the levels of the dopaminergic neuron marker, phospho-tyrosine hydroxylase (p-TH), were also dose-dependently increased upon treatment with curcumin I. Our results clearly demonstrated that curcumin I protects neurons against oxidative damage, as shown by attenuation of p-p38 expression, caspase-3-activation, and toxic quinoprotein formation, together with the restoration of p-TH levels. This study provides evidence for the therapeutic potential of curcumin I in the chemoprevention of oxidative stress-related neurodegeneration.

  3. Differential expression of p38 MAPK α, β, γ, δ isoforms in nucleus pulposus modulates macrophage polarization in intervertebral disc degeneration

    PubMed Central

    Yang, Chen; Cao, Peng; Gao, Yang; Wu, Ming; Lin, Yun; Tian, Ye; Yuan, Wen

    2016-01-01

    P38MAPK mediates cytokine induced inflammation in nucleus pulposus (NP) cells and involves in multiple cellular processes which are related to intervertebral disc degeneration (IDD). The aim of this study was to investigate the expression, activation and function of p38 MAPK isoforms (α,β, γ and δ) in degenerative NP and the effect of p38 activation in NP cells on macrophage polarization. P38 α, β and δ isoforms are preferential expressed, whereas the p38γ isoform is absent in human NP tissue. LV-sh-p38α, sh-p38β transfection in NP cells significantly decreased the ADAMTS-4,-5, MMP-13,CCL3 expression and restored collagen-II and aggrecan expression upon IL-1β stimulation. As compared with p38α and p38β, p38δ exhibited an opposite effect on ADAMTS-4,-5, MMP-13 and aggrecan expression in NP cells. Furthermore, the production of GM-CSF and IFNγ which were trigged by p38α or p38β in NP cells induced macrophage polarization into M1 phenotype. Our finding indicates that p38 MAPK α, β and δ isoform are predominantly expressed and activated in IDD. P38 positive NP cells modulate macrophage polarization through the production of GM-CSF and IFNγ. Hence, Our study suggests that selectively targeting p38 isoforms could ameliorate the inflammation in IDD and regard IDD progression. PMID:26911458

  4. COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

    SciTech Connect

    Kook, Sung-Ho; Lim, Shin-Saeng; Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol; Kwon, Jungkee; Hwang, Jae-Won; Bae, Cheol-Hyeon; Seo, Young-Kwon; Lee, Jeong-Chae

    2014-12-12

    Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways.

  5. Selective p38α MAPK deletion in serotonergic neurons produces stress resilience in models of depression and addiction.

    PubMed

    Bruchas, Michael R; Schindler, Abigail G; Shankar, Haripriya; Messinger, Daniel I; Miyatake, Mayumi; Land, Benjamin B; Lemos, Julia C; Hagan, Catherine E; Neumaier, John F; Quintana, Albert; Palmiter, Richard D; Chavkin, Charles

    2011-08-11

    Maladaptive responses to stress adversely affect human behavior, yet the signaling mechanisms underlying stress-responsive behaviors remain poorly understood. Using a conditional gene knockout approach, the α isoform of p38 mitogen-activated protein kinase (MAPK) was selectively inactivated by AAV1-Cre-recombinase infection in specific brain regions or by promoter-driven excision of p38α MAPK in serotonergic neurons (by Slc6a4-Cre or ePet1-Cre) or astrocytes (by Gfap-CreERT2). Social defeat stress produced social avoidance (a model of depression-like behaviors) and reinstatement of cocaine preference (a measure of addiction risk) in wild-type mice, but not in mice having p38α MAPK selectively deleted in serotonin-producing neurons of the dorsal raphe nucleus. Stress-induced activation of p38α MAPK translocated the serotonin transporter to the plasma membrane and increased the rate of transmitter uptake at serotonergic nerve terminals. These findings suggest that stress initiates a cascade of molecular and cellular events in which p38α MAPK induces a hyposerotonergic state underlying depression-like and drug-seeking behaviors. PMID:21835346

  6. Hypoxia-induced Bcl-2 expression in endothelial cells via p38 MAPK pathway

    SciTech Connect

    Zhang, Cui-Li; Song, Fei; Zhang, Jing; Song, Q.H.

    2010-04-16

    Angiogenesis and apoptosis are reciprocal processes in endothelial cells. Bcl-2, an anti-apoptotic protein, has been found to have angiogenic activities. The purpose of this study was to determine the role of Bcl-2 in hypoxia-induced angiogenesis in endothelial cells and to investigate the underlying mechanisms. Human aortic endothelial cells (HAECs) were exposed to hypoxia followed by reoxygenation. Myocardial ischemia and reperfusion mouse model was used and Bcl-2 expression was assessed. Bcl-2 expression increased in a time-dependent manner in response to hypoxia from 2 to 72 h. Peak expression occurred at 12 h (3- to 4-fold, p < 0.05). p38 inhibitor (SB203580) blocked hypoxia-induced Bcl-2 expression, whereas PKC, ERK1/2 and PI3K inhibitors did not. Knockdown of Bcl-2 resulted in decreased HAECs' proliferation and migration. Over-expression of Bcl-2 increased HAECs' tubule formation, whereas knockdown of Bcl-2 inhibited this process. In this model of myocardial ischemia and reperfusion, Bcl-2 expression was increased and was associated with increased p38 MAPK activation. Our results showed that hypoxia induces Bcl-2 expression in HAECs via p38 MAPK pathway.

  7. p38 MAPK and PI3K/AKT Signalling Cascades inParkinson’s Disease

    PubMed Central

    Jha, Saurabh Kumar; Jha, Niraj Kumar; Kar, Rohan; Ambasta, Rashmi K; Kumar, Pravir

    2015-01-01

    Parkinson's disease (PD) is a chronic neurodegenerative condition which has the second largest incidence rate among all other neurodegenerative disorders barring Alzheimer's disease (AD). Currently there is no cure and researchers continue to probe the therapeutic prospect in cell cultures and animal models of PD. Out of the several factors contributing to PD prognosis, the role of p38 MAPK (Mitogen activated protein-kinase) and PI3K/AKT signalling module in PD brains is crucial because the impaired balance between the pro- apoptotic and anti-apoptotic pathways trigger unwanted phenotypes such as microglia activation, neuroinflammation, oxidative stress and apoptosis. These factors continue challenging the brain homeostasis in initial stages thereby essentially assisting the dopaminergic (DA) neurons towards progressive degeneration in PD. Neurotherapeutics against PD shall then be targeted against the misregulated accomplices of the p38 and PI3K/AKT cascades. In this review, we have outlined many such established mechanisms involving the p38 MAPK and PI3K/AKT pathways which can offer therapeutic windows for the rectification of aberrant DA neuronal dynamics in PD brains. PMID:26261796

  8. Anti-inflammatory effects of a p38 mitogen-activated protein kinase inhibitor during human endotoxemia.

    PubMed

    Branger, Judith; van den Blink, Bernt; Weijer, Sebastiaan; Madwed, Jeffrey; Bos, Carina L; Gupta, Abhya; Yong, Chan-Loi; Polmar, Stephen H; Olszyna, Dariusz P; Hack, C Erik; van Deventer, Sander J H; Peppelenbosch, Maikel P; van der Poll, Tom

    2002-04-15

    The p38 mitogen-activated protein kinase (MAPK) participates in intracellular signaling cascades resulting in inflammatory responses. Therefore, inhibition of the p38 MAPK pathway may form the basis of a new strategy for treatment of inflammatory diseases. However, p38 MAPK activation during systemic inflammation in humans has not yet been shown, and its functional significance in vivo remains unclear. Hence, we exposed 24 healthy male subjects to an i.v. dose of LPS (4 ng/kg), preceded 3 h earlier by orally administered 600 or 50 mg BIRB 796 BS (an in vitro p38 MAPK inhibitor) or placebo. Both doses of BIRB 796 BS significantly inhibited LPS-induced p38 MAPK activation in the leukocyte fraction of the volunteers. Cytokine production (TNF-alpha, IL-6, IL-10, and IL-1R antagonist) was strongly inhibited by both low and high dose p38 MAPK inhibitor. In addition, p38 MAPK inhibition diminished leukocyte responses, including neutrophilia, release of elastase-alpha(1)-antitrypsin complexes, and up-regulation of CD11b with down-regulation of L-selectin. Finally, blocking p38 MAPK decreased C-reactive protein release. These data identify p38 MAPK as a principal mediator of the inflammatory response to LPS in humans. Furthermore, the anti-inflammatory potential of an oral p38 MAPK inhibitor in humans in vivo suggests that p38 MAPK inhibitors may provide a new therapeutic option in the treatment of inflammatory diseases.

  9. Parainfluenza Virus Type 1 Induces Epithelial IL-8 Production via p38-MAPK Signalling

    PubMed Central

    Galván Morales, Miguel Ángel; Cabello Gutiérrez, Carlos; Mejía Nepomuceno, Fidencio; Valle Peralta, Leticia; Valencia Maqueda, Elba; Manjarrez Zavala, María Eugenia

    2014-01-01

    Human parainfluenza virus type 1 (HPIV-1) is the most common cause of croup in infants. The aim of this study was to describe molecular mechanisms associated with IL-8 production during HPIV-1 infection and the role of viral replication in MAPK synthesis and activation. An in vitro model of HPIV-1 infection in the HEp-2 and A549 cell lines was used; a kinetic-based ELISA for IL-8 detection was also used, phosphorylation of the mitogen-activated protein kinases (MAPKs) was identified by Western blot analysis, and specific inhibitors for each kinase were used to identify which MAPK was involved. Inactivated viruses were used to assess whether viral replication is required for IL-8 production. Results revealed a gradual increase in IL-8 production at different selected times, when phosphorylation of MAPK was detected. The secretion of IL-8 in the two cell lines infected with the HPIV-1 is related to the phosphorylation of the MAPK as well as viral replication. Inhibition of p38 suppressed the secretion of IL-8 in the HEp-2 cells. No kinase activation was observed when viruses were inactivated. PMID:25013817

  10. Inhibitory effects of [6]-gingerol on PMA-induced COX-2 expression and activation of NF-kappaB and p38 MAPK in mouse skin.

    PubMed

    Kim, Sue Ok; Chun, Kyung-Soo; Kundu, Joydeb Kumar; Surh, Young-Joon

    2004-01-01

    [6]-Gingerol, a major pungent ingredient of ginger (Zingiber officinale Roscoe, Zingiberaceae), has a wide array of pharmacologic effects. Previous studies have demonstrated that [6]-gingerol inhibits mouse skin tumor promotion and anchorage-independent growth of cultured mouse epidermal cells stimulated with epidermal growth factor. Cyclooxygenase-2 (COX-2), a key enzyme in the prostaglandin biosynthesis, has been recognized as a molecular target for many anti-inflammatory as well as chemopreventive agents. Topical application of [6]-gingerol inhibited phorbol 12-myristate 13-acetate -induced COX-2 expression. One of the essential transcription factors responsible for COX-2 induction is NF-kappaB. [6]-Gingerol suppressed NF-kappaB DNA binding activity in mouse skin. In addition, [6]-gingerol inhibited the phoshorylation of p38 mitogen-activated protein kinase which may account for its inactivation of NF-kappaB and suppression of COX-2 expression. PMID:15630166

  11. Resistin increases platelet P-selectin levels via p38 MAPK signal pathway.

    PubMed

    Qiu, Wenbing; Chen, Naping; Zhang, Qin; Zhuo, Liyuan; Wang, Xihong; Wang, Dongming; Jin, Hong

    2014-03-01

    Resistin, an adipokine associated with the metabolic syndrome, is believed to have a role in thrombotic conditions. This work analyses the effects of resistin on P-selectin expression using a combination of ex vivo human studies, in vivo animal models and in vitro cell cultures. Human platelets and vascular endothelial cells were incubated with resistin, with or without anti-Toll-like receptor 4 (TLR-4) or mitogen-activated protein kinases (MAPK) pathway inhibitors, whereas mice were treated with resistin infusion followed by analysis of P-selectin expression. Resistin increased both human and murine platelet P-selectin expression compared with controls (human: 48.02% ± 7.6% vs 35.12% ± 2.62%, p < 0.05; mouse: 8.17% ± 0.37% vs 4.44% ± 0.37%, p < 0.05), through the p38 MAPK pathway. In contrast, resistin had no effect on endothelial P-selectin production. We conclude that resistin induces platelet activation by increasing P-selectin expression through the p38 MAPK-dependent pathway. These data provide one mechanism for the prothrombotic state in individuals with the metabolic syndrome.

  12. PKR is a novel functional direct player that coordinates skeletal muscle differentiation via p38MAPK/AKT pathways.

    PubMed

    Alisi, A; Spaziani, A; Anticoli, S; Ghidinelli, M; Balsano, C

    2008-03-01

    Myogenic differentiation is a highly orchestrated multistep process controlled by extracellular growth factors that modulate largely unknown signals into the cell affecting the muscle-transcription program. P38MAPK-dependent signalling, as well as PI3K/Akt pathway, has a key role in the control of muscle gene expression at different stages during the myogenic process. P38MAPK affects the activities of transcription factors, such as MyoD and myogenin, and contributes, together with PI3K/Akt pathway, to control the early and late steps of myogenic differentiation. The aim of our work was to better define the role of PKR, a dsRNA-activated protein kinase, as potential component in the differentiation program of C2C12 murine myogenic cells and to correlate its activity with p38MAPK and PI3K/Akt myogenic regulatory pathways. Here, we demonstrate that PKR is an essential component of the muscle development machinery and forms a functional complex with p38MAPK and/or Akt, contributing to muscle differentiation of committed myogenic cells in vitro. Inhibition of endogenous PKR activity by a specific (si)RNA and a PKR dominant-negative interferes with the myogenic program of C2C12 cells, causing a delay in activation of myogenic specific genes and inducing the formation of thinner myofibers. In addition, the construction of three PKR mutants allowed us to demonstrate that both N and C-terminal regions of PKR are critical for the interaction with p38MAPK and Akt. The novel discovered complex permits PKR to timely regulate the inhibition/activation of p38MAPK and Akt, controlling in this way the different steps characterizing skeletal muscle differentiation.

  13. TGF{beta}1 induces apoptosis in invasive prostate cancer and bladder cancer cells via Akt-independent, p38 MAPK and JNK/SAPK-mediated activation of caspases

    SciTech Connect

    Al-Azayzih, Ahmad; Gao, Fei; Goc, Anna; Somanath, Payaningal R.

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer TGF{beta} induced apoptosis in invasive prostate cancer and bladder cancer cells. Black-Right-Pointing-Pointer TGF{beta} inhibited prostate/bladder cancer cell proliferation and colony/foci formation. Black-Right-Pointing-Pointer TGF{beta} induced prostate/bladder cancer cell apoptosis independent of Akt inhibition. Black-Right-Pointing-Pointer TGF{beta} inhibited ERK1/2 phosphorylation in prostate/bladder cancer cells. Black-Right-Pointing-Pointer TGF{beta} induced p38 MAPK and JNK-mediated activation of caspases-9, -8 and -3. -- Abstract: Recent findings indicate that advanced stage cancers shun the tumor suppressive actions of TGF{beta} and inexplicably utilize the cytokine as a tumor promoter. We investigated the effect of TGF{beta}1 on the survival and proliferation of invasive prostate (PC3) and bladder (T24) cancer cells. Our study indicated that TGF{beta}1 decreased cell viability and induced apoptosis in invasive human PC3 and T24 cells via activation of p38 MAPK-JNK-Caspase9/8/3 pathway. Surprisingly, no change in the phosphorylation of pro-survival Akt kinase was observed. We postulate that TGF{beta}1 pathway may be utilized for specifically targeting urological cancers without inflicting side effects on normal tissues.

  14. FSH-induced p38-MAPK-mediated dephosphorylation at serine 727 of the signal transducer and activator of transcription 1 decreases Cyp1b1 expression in mouse granulosa cells.

    PubMed

    Du, Xue-Hai; Zhou, Xiao-Long; Cao, Rui; Xiao, Peng; Teng, Yun; Ning, Cai-Bo; Liu, Hong-Lin

    2015-01-01

    Most mammalian follicles undergo atresia at various stages before ovulation, and granulosa cell apoptosis is a major cause of antral follicular atresia. Estradiol is an essential mitogen for granulosa cell proliferation in vivo and inhibition of apoptosis. The estradiol-producing capacity and metabolism levels are important for follicle health, and sufficient estradiol is necessary for follicle development and ovulation. Cyp1b1, a member of the cytochrome P450 1 subfamily, is responsible for the metabolism of a wide variety of halogenated and polycyclic aromatic hydrocarbons in diverse tissues. In mouse follicles, Cyp1b1 converts estradiol to 4-hydroxyestradiol. We investigated mouse granulosa cells (MGCs) in vivo and in vitro and found that Cyp1b1 played a crucial role in estradiol metabolism in dominant follicles. Follicle-stimulating hormone (FSH) decreased estrogen metabolism by reducing Cyp1b1 mRNA and protein levels in MGCs. Furthermore, FSH regulated signal transducer and activator of transcription 1 (STAT1), a significant transcription factor of Cyp1b1, by mediating the dephosphorylation of STAT1 on serine 727 (Ser(727)) in MGCs. p38 mitogen-activated protein kinase (MAPK) may be involved in the FSH-induced dephosphorylation of STAT1 on Ser(727) in MGCs. These results suggested that FSH functions via p38 MAPK-induced dephosphorylation at Ser(727) of STAT1 to downregulate Cyp1b1 expression and maintain the estradiol levels in mouse dominant follicles.

  15. The case for inhibiting p38 mitogen-activated protein kinase in heart failure.

    PubMed

    Arabacilar, Pelin; Marber, Michael

    2015-01-01

    This minireview discusses the evidence that the inhibition of p38 mitogen-activated protein kinases (p38 MAPKs) maybe of therapeutic value in heart failure. Most previous experimental studies, as well as past and ongoing clinical trials, have focussed on the role of p38 MAPKs in myocardial infarction and acute coronary syndromes. There is now growing evidence that these kinases are activated within the myocardium of the failing human heart and in the heart and blood vessels of animal models of heart failure. Furthermore, from a philosophical viewpoint the chronic activation of the adaptive stress pathways that lead to the activation of p38 MAPKs in heart failure is analogous to the chronic activation of the sympathetic, renin-aldosterone-angiotensin and neprilysin systems. These have provided some of the most effective therapies for heart failure. This minireview questions whether similar and synergistic advantages would follow the inhibition of p38 MAPKs.

  16. Ssanghwa-tang, an oriental herbal cocktail, exerts anti-melanogenic activity by suppression of the p38 MAPK and PKA signaling pathways in B16F10 cells

    PubMed Central

    2013-01-01

    Background Ssanghwa-tang (SHT) is a widely used medication for the treatment of fatigue, pain, inflammation, hypothermia, erectile dysfunction, cancer, and osteoporosis in Asia, however, role of SHT on the melanin synthesis has not been checked previously. Thus, the present study was designed to determine the effect of SHT on α-melanocyte stimulating hormone (α-MSH)-induced melanogensis and its mechanisms of action in murine B16F10 melanoma cells. Method Cellular melanin content and tyrosinase activity in murine B16F10 melanoma cells were determined after α-MSH stimulation with or without pre-treatment of SHT at the concentration of 250 and 500 μg/ml. Expression level of tyrosinase, tyrosinase-related protein 1 (TRP-1), TRP-2, microphthalmia-associated transcription factor (MITF), and activation of c-AMP-dependent protein kinase (PKA), c-AMP-related element binding protein (CREB), and mitogen-activated protein kinases (MAPKs) were examined by Western blot analysis. Results SHT significantly inhibited α-MSH-induced melanin synthesis and tyrosinase activity, and also decreased α-MSH-induced expression of MITF, tyrosinase, and TRP-1. In addition, SHT remarkably suppressed tyrosinase, CRE, and MITF luciferase reporter activity in a resting state as well as in α-MSH-stimulating condition. Phosphorylation of p38 MAPK by α-MSH stimulation was efficiently blocked by SHT pre-treatment. Moreover, SHT as an herbal cocktail showed synergistic anti-melanogenic effect compared with that of each single constituent herb. Conclusion SHT efficiently inhibited c-AMP-induced melanin synthesis in B16F10 cells via suppression of PKA and p38 MAPK signaling pathways and subsequently decreased the level of CREB phosphorylation, MITF, and melanogenic enzymes. These results indicate that SHT may be useful as herbal medicine for treating hyperpigmentation and cosmetics as a skin-whitening agent. PMID:23981281

  17. Osmotic stress induces the phosphorylation of WNK4 Ser575 via the p38MAPK-MK pathway

    PubMed Central

    Maruyama, Junichi; Kobayashi, Yumie; Umeda, Tsuyoshi; Vandewalle, Alain; Takeda, Kohsuke; Ichijo, Hidenori; Naguro, Isao

    2016-01-01

    The With No lysine [K] (WNK)-Ste20-related proline/alanine-rich kinase (SPAK)/oxidative stress-responsive kinase 1 (OSR1) pathway has been reported to be a crucial signaling pathway for triggering pseudohypoaldosteronism type II (PHAII), an autosomal dominant hereditary disease that is characterized by hypertension. However, the molecular mechanism(s) by which the WNK-SPAK/OSR1 pathway is regulated remain unclear. In this report, we identified WNK4 as an interacting partner of a recently identified MAP3K, apoptosis signal-regulating kinase 3 (ASK3). We found that WNK4 is phosphorylated in an ASK3 kinase activity-dependent manner. By exploring the ASK3-dependent phosphorylation sites, we identified Ser575 as a novel phosphorylation site in WNK4 by LC-MS/MS analysis. ASK3-dependent WNK4 Ser575 phosphorylation was mediated by the p38MAPK-MAPK-activated protein kinase (MK) pathway. Osmotic stress, as well as hypotonic low-chloride stimulation, increased WNK4 Ser575 phosphorylation via the p38MAPK-MK pathway. ASK3 was required for the p38MAPK activation induced by hypotonic stimulation but was not required for that induced by hypertonic stimulation or hypotonic low-chloride stimulation. Our results suggest that the p38MAPK-MK pathway might regulate WNK4 in an osmotic stress-dependent manner but its upstream regulators might be divergent depending on the types of osmotic stimuli. PMID:26732173

  18. Effect of 3G cell phone exposure with computer controlled 2-D stepper motor on non-thermal activation of the hsp27/p38MAPK stress pathway in rat brain.

    PubMed

    Kesari, Kavindra Kumar; Meena, Ramovatar; Nirala, Jayprakash; Kumar, Jitender; Verma, H N

    2014-03-01

    Cell phone radiation exposure and its biological interaction is the present concern of debate. Present study aimed to investigate the effect of 3G cell phone exposure with computer controlled 2-D stepper motor on 45-day-old male Wistar rat brain. Animals were exposed for 2 h a day for 60 days by using mobile phone with angular movement up to zero to 30°. The variation of the motor is restricted to 90° with respect to the horizontal plane, moving at a pre-determined rate of 2° per minute. Immediately after 60 days of exposure, animals were scarified and numbers of parameters (DNA double-strand break, micronuclei, caspase 3, apoptosis, DNA fragmentation, expression of stress-responsive genes) were performed. Result shows that microwave radiation emitted from 3G mobile phone significantly induced DNA strand breaks in brain. Meanwhile a significant increase in micronuclei, caspase 3 and apoptosis were also observed in exposed group (P < 0.05). Western blotting result shows that 3G mobile phone exposure causes a transient increase in phosphorylation of hsp27, hsp70, and p38 mitogen-activated protein kinase (p38MAPK), which leads to mitochondrial dysfunction-mediated cytochrome c release and subsequent activation of caspases, involved in the process of radiation-induced apoptotic cell death. Study shows that the oxidative stress is the main factor which activates a variety of cellular signal transduction pathways, among them the hsp27/p38MAPK is the pathway of principle stress response. Results conclude that 3G mobile phone radiations affect the brain function and cause several neurological disorders.

  19. Sorbitol induces apoptosis of human colorectal cancer cells via p38 MAPK signal transduction.

    PubMed

    Lu, Xue; Li, Chun; Wang, Yong-Kun; Jiang, Kun; Gai, Xiao-Dong

    2014-06-01

    Sorbitol has been reported to have anticancer effects in several tumor models, however its effects on colorectal cancer remain elusive. In the present study, the effects of sorbitol on growth inhibition and apoptosis in the colorectal cancer HCT116 cell line were evaluated and its mechanism of action was examined. An MTT assay was utilized to determine the effect of sorbitol on HCT116 cell proliferation at different time points and variable doses. Western blot analysis was used to examine the effect of sorbitol on apoptosis-related protein expression and the p38 MAPK signaling pathway. The results revealed that sorbitol may inhibit the growth of HCT116 cells in a time- and dose-dependent manner. Following treatment with sorbitol for 3 h, western blotting demonstrated cleavage of the caspase-3 zymogen protein and a cleavage product of poly (ADP-ribose) polymerase (PARP), a known substrate of caspase-3, was also evident. During sorbitol-induced apoptosis, the mitochondrial pathway was activated by a dose-dependent increase in Bax expression and cytochrome c release, while the expression of anti-apoptotic protein Bcl-2 was significantly decreased in a dose-dependent manner. The investigation for the downstream signal pathway revealed that sorbitol-induced apoptosis was mediated by an increase in phosphorylated p38 MAPK expression. Overall, the observations from the present study imply that sorbitol causes increased levels of Bax in response to p38 MAPK signaling, which results in the initiation of the mitochondrial death cascade. Therefore, sorbitol is a promising candidate as a potential chemotherapeutic agent for the treatment of colorectal cancer HCT116 cells.

  20. Calcium paradox induces apoptosis in the isolated perfused Rana ridibunda heart: involvement of p38-MAPK and calpain.

    PubMed

    Aggeli, Ioanna-Katerina; Zacharias, Triantafyllos; Papapavlou, Georgia; Gaitanaki, Catherine; Beis, Isidoros

    2013-12-01

    "Calcium paradox" as a term describes the deleterious effects conferred to a heart perfused with a calcium-free solution followed by repletion, including loss of mechanical activity and sarcomere disruption. Given that the signaling mechanisms triggered by calcium paradox remain elusive, in the present study, we tried to investigate them in the isolated perfused heart from Rana ridibunda. Calcium paradox was found to markedly activate members of the MAPKs (p43-ERK, JNKs, p38-MAPK). In addition to lactate dehydrogenase (LDH) release in the perfusate (indicative of necrosis), we also confirmed the occurrence of apoptosis by using the TUNEL assay and identifying poly(ADP-ribose) polymerase (PARP) fragmentation and upregulated Bax expression. Furthermore, using MDL28170 (a selective calpain inhibitor), a role for this protease was revealed. In addition, various divalent cations were shown to exert a protective effect against the calcium paradox. Interestingly, SB203580, a p38-MAPK inhibitor, alleviated calcium-paradox-conferred apoptosis. This result indicates that p38-MAPK plays a pro-apoptotic role, contributing to the resulting myocardial dysfunction and cell death. To our knowledge, this is the first time that the calcium paradox has been shown to induce apoptosis in amphibians, with p38-MAPK and calpain playing significant roles.

  1. Fasudil inhibits LPS-induced migration of retinal microglial cells via regulating p38-MAPK signaling pathway

    PubMed Central

    Xu, Fan; Xu, Yue; Zhu, Liqiong; Rao, Pinhong; Wen, Jiamin; Sang, Yunyun; Shang, Fu

    2016-01-01

    Purpose To investigate the effect and possible molecular mechanisms of fasudil on retinal microglial (RMG) cell migration. Methods Primary cultured RMG cells were incubated with lipopolysaccharide (LPS), fasudil, and/or SB203580 (a p38 inhibitor). RMG cell motility was determined with the scratch wound assay and the Transwell migration assay. The phosphorylation of p38 and levels of matrix metalloproteinase 2 (MMP-2) and MMP-9 were measured with western blot. Results In the scratch-induced migration assay, as well as in the Transwell migration assay, the results indicated that LPS stimulated the migratory potential of RMG cells and fasudil significantly reduced LPS-stimulated RMG cell migration in a concentration-dependent manner. However, fasudil had no effect on RMG cell migration in the absence of LPS stimulation. Moreover, fasudil reduced the level of phosphor-p38 mitogen-activated protein kinase (p-p38-MAPK) in a concentration-dependent manner, without effects on the levels of phospho-p44/42 (p-ERK1/2) and phospho-c-Jun N-terminal kinase (p-JNK). Cotreatment with SB203580 (a p38 inhibitor) and fasudil resulted in the synergistic reduction of MMP-2, MMP-9, and p-p38-MAPK, as well as a reduction in the LPS-stimulated migration capabilities of the RMG cells, suggesting fasudil suppresses the LPS-stimulated migration of RMG cells via directly downregulating the p38-MAPK signaling pathway. Conclusions Our studies indicated that fasudil inhibited LPS-stimulated RMG cell migration via suppression of the p38-MAPK signaling pathway. PMID:27441000

  2. Preventing p38 MAPK-mediated MafA degradation ameliorates β-cell dysfunction under oxidative stress.

    PubMed

    El Khattabi, Ilham; Sharma, Arun

    2013-07-01

    The reduction in the expression of glucose-responsive insulin gene transcription factor MafA accompanies the development of β-cell dysfunction under oxidative stress/diabetic milieu. Humans with type 2 diabetes have reduced MafA expression, and thus preventing this reduction could overcome β-cell dysfunction and diabetes. We previously showed that p38 MAPK, but not glycogen synthase kinase 3 (GSK3), is a major regulator of MafA degradation under oxidative stress. Here, we examined the mechanisms of this degradation and whether preventing MafA degradation under oxidative stress will overcome β-cell dysfunction. We show that under oxidative and nonoxidative conditions p38 MAPK directly binds to MafA and triggers MafA degradation via ubiquitin proteasomal pathway. However, unlike nonoxidative conditions, MafA degradation under oxidative stress depended on p38 MAPK-mediated phosphorylation at threonine (T) 134, and not T57. Furthermore the expression of alanine (A) 134-MafA, but not A57-MafA, reduced the oxidative stress-mediated loss of glucose-stimulated insulin secretion, which was independent of p38 MAPK action on protein kinase D, a regulator of insulin secretion. Interestingly, the expression of proteasomal activator PA28γ that degrades GSK3-phosphorylated (including T57) MafA was reduced under oxidative stress, explaining the dominance of p38 MAPK over the GSK3 pathway in regulating MafA stability under oxidative stress. These results identify two distinct pathways mediating p38 MAPK-dependent MafA degradation under oxidative and nonoxidative conditions and show that inhibiting MafA degradation under oxidative stress ameliorates β-cell dysfunction and could lead to novel therapies for diabetes.

  3. p38 MAPK regulates PKAα and CUB-serine protease in Amphibalanus amphitrite cyprids

    PubMed Central

    Zhang, Gen; He, Li-Sheng; Him Wong, Yue; Xu, Ying; Zhang, Yu; Qian, Pei-Yuan

    2015-01-01

    The MKK3-p38 MAPK pathway has been reported to mediate larval settlement in Amphibalanus (=Balanus) amphitrite. To clarify the underlying molecular mechanism, we applied label-free proteomics to analyze changes in the proteome of cyprids treated with a p38 MAPK inhibitor. The results showed that the expression levels of 80 proteins were significantly modified (p < 0.05). These differentially expressed proteins were assigned to 15 functional groups according to the KOG database and 9 pathways were significantly enriched. Further analysis revealed that p38 MAPK might regulate the energy supply and metamorphosis. Two potential regulatory proteins, CUB-serine protease and PKAα, were both down-regulated in expression. CUB-serine protease localized to postaxial seta 2 and 3, as well as the 4 subterminal sensilla in the antennule. Importantly, it was co-localized with the neuron transmitter serotonin in the sections, suggesting that the CUB-serine protease was present in the neural system. PKAα was highly expressed during the cyprid and juvenile stages, and it was co-localized with phospho-p38 MAPK (pp38 MAPK) to the cement gland, suggesting that PKAα might have some functions in cement glands. Overall, p38 MAPK might regulate multiple functions in A. amphitrite cyprids, including the energy supply, metamorphosis, neural system and cement glands. PMID:26434953

  4. p38 MAPK regulates PKAα and CUB-serine protease in Amphibalanus amphitrite cyprids.

    PubMed

    Zhang, Gen; He, Li-Sheng; Him Wong, Yue; Xu, Ying; Zhang, Yu; Qian, Pei-Yuan

    2015-01-01

    The MKK3-p38 MAPK pathway has been reported to mediate larval settlement in Amphibalanus (=Balanus) amphitrite. To clarify the underlying molecular mechanism, we applied label-free proteomics to analyze changes in the proteome of cyprids treated with a p38 MAPK inhibitor. The results showed that the expression levels of 80 proteins were significantly modified (p < 0.05). These differentially expressed proteins were assigned to 15 functional groups according to the KOG database and 9 pathways were significantly enriched. Further analysis revealed that p38 MAPK might regulate the energy supply and metamorphosis. Two potential regulatory proteins, CUB-serine protease and PKAα, were both down-regulated in expression. CUB-serine protease localized to postaxial seta 2 and 3, as well as the 4 subterminal sensilla in the antennule. Importantly, it was co-localized with the neuron transmitter serotonin in the sections, suggesting that the CUB-serine protease was present in the neural system. PKAα was highly expressed during the cyprid and juvenile stages, and it was co-localized with phospho-p38 MAPK (pp38 MAPK) to the cement gland, suggesting that PKAα might have some functions in cement glands. Overall, p38 MAPK might regulate multiple functions in A. amphitrite cyprids, including the energy supply, metamorphosis, neural system and cement glands. PMID:26434953

  5. Tianeptine potentiates AMPA receptors by activating CaMKII and PKA via the p38, p42/44 MAPK and JNK pathways.

    PubMed

    Szegedi, Viktor; Juhász, Gábor; Zhang, Xiaoqun; Barkóczi, Balázs; Qi, Hongshi; Madeira, Alexandra; Kapus, Gábor; Svenningsson, Per; Spedding, Michael; Penke, Botond

    2011-12-01

    Impairments of cellular plasticity appear to underlie the pathophysiology of major depression. Recently, elevated levels of phosphorylated AMPA receptor were implicated in the antidepressant effect of various drugs. Here, we investigated the effects of an antidepressant, Tianeptine, on synaptic function and GluA1 phosphorylation using murine hippocampal slices and in vivo single-unit recordings. Tianeptine, but not imipramine, increased AMPA receptor-mediated neuronal responses both in vitro and in vivo, in a staurosporine-sensitive manner. Paired-pulse ratio was unaltered by Tianeptine, suggesting a postsynaptic site of action. Tianeptine, 10 μM, enhanced the GluA1-dependent initial phase of LTP, whereas 100 μM impaired the latter phases, indicating a critical role of GluA1 subunit phosphorylation in the excitation. Tianeptine rapidly increased the phosphorylation level of Ser(831)-GluA1 and Ser(845)-GluA1. Using H-89 and KN-93, we show that the activation of both PKA and CaMKII is critical in the effect of Tianeptine on AMPA responses. Moreover, the phosphorylation states of Ser(217/221)-MEK and Thr(183)/Tyr(185)-p42MAPK were increased by Tianeptine and specific kinase blockers of the MAPK pathways (PD 98095, SB 203580 and SP600125) prevented the effects of Tianeptine. Overall these data suggest that Tianeptine potentiates several signaling cascades associated with synaptic plasticity and provide further evidence that a major mechanism of action for Tianeptine is to act as an enhancer of glutamate neurotransmission via AMPA receptors.

  6. p38 MAPK Participates in Muscle-Specific RING Finger 1-Mediated Atrophy in Cast-Immobilized Rat Gastrocnemius Muscle

    PubMed Central

    Kim, Junghwan; Won, Kyung-Jong; Lee, Hwan Myung; Hwang, Byong-Yong; Bae, Young-Min; Choi, Whan Soo; Song, Hyuk; Lim, Ki Won; Lee, Chang-Kwon

    2009-01-01

    Skeletal muscle atrophy is a common phenomenon during the prolonged muscle disuse caused by cast immobilization, extended aging states, bed rest, space flight, or other factors. However, the cellular mechanisms of the atrophic process are poorly understood. In this study, we investigated the involvement of mitogen-activated protein kinase (MAPK) in the expression of muscle-specific RING finger 1 (MuRF1) during atrophy of the rat gastrocnemius muscle. Histological analysis revealed that cast immobilization induced the atrophy of the gastrocnemius muscle, with diminution of muscle weight and cross-sectional area after 14 days. Cast immobilization significantly elevated the expression of MuRF1 and the phosphorylation of p38 MAPK. The starvation of L6 rat skeletal myoblasts under serum-free conditions induced the phosphorylation of p38 MAPK and the characteristics typical of cast-immobilized gastrocnemius muscle. The expression of MuRF1 was also elevated in serum-starved L6 myoblasts, but was significantly attenuated by SB203580, an inhibitor of p38 MAPK. Changes in the sizes of L6 myoblasts in response to starvation were also reversed by their transfection with MuRF1 small interfering RNA or treatment with SB203580. From these results, we suggest that the expression of MuRF1 in cast-immobilized atrophy is regulated by p38 MAPK in rat gastrocnemius muscles. PMID:20054497

  7. Role of p38 MAPK in LPS induced pro-inflammatory cytokine and chemokine gene expression in equine leukocytes.

    PubMed

    Neuder, Laura E; Keener, Jamie M; Eckert, Rachael E; Trujillo, Jennifer C; Jones, Samuel L

    2009-06-15

    Endotoxemia occurs when bacterial lipopolysaccharide (LPS) in the blood induces a dysregulated inflammatory response, resulting in circulatory shock and multi-organ failure. Laminitis is a common complication in endotoxemic horses and is frequently the reason for humane euthanasia of these cases. Blood leukocytes are a principal target of LPS in endotoxemia leading to activation of multiple signal transduction pathways involved in the induction of a number of pro-inflammatory genes. In other animal models, the p38 mitogen activated protein kinase (MAPK) pathway has been associated with induced expression of tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-1beta, IL-6 and IL-8. The goal of this study was to determine the role of the p38 MAPK pathway in the induction of these pro-inflammatory cytokine and chemokine genes in LPS-stimulated equine leukocytes. Stimulation of equine peripheral blood leukocytes resulted in an increase in TNFalpha, IL-1beta, IL-6 and IL-8 mRNA levels. Pharmacological inhibition of p38 MAPK activity with SB203580 or SB202190 reduced the ability of LPS stimulation to increase mRNA concentrations for all four genes. However, only SB203580 pretreatment significantly reduced LPS-stimulated IL-1beta and IL-8 mRNA expression and only pretreatment with SB202190 significantly reduced LPS-stimulated TNFalpha and IL-6 mRNA expression. From this study we conclude TNFalpha, IL-1beta, IL-6 and IL-8 are induced upon LPS stimulation of equine leukocytes and that this induction of gene expression is dependent on the p38 MAPK pathway. However, there are differences in the efficacy of the p38 inhibitors tested here that may be explained by differences in specificity or potency. This study provides evidence for the use of selective p38 MAPK inhibitors as potential therapeutics for the treatment of equine endotoxemia.

  8. TNF-α stimulates System A amino acid transport in primary human trophoblast cells mediated by p38 MAPK signaling.

    PubMed

    Aye, Irving L M H; Jansson, Thomas; Powell, Theresa L

    2015-10-01

    Maternal obesity and gestational diabetes mellitus (GDM) increase the risk of delivering infants that are large for gestational age with greater adiposity, who are prone to the development of metabolic disease in childhood and beyond. These maternal conditions are also associated with increased levels of the proinflammatory cytokine TNF-α in maternal tissues and the placenta. Recent evidence suggests that changes in placental amino acid transport contribute to altered fetal growth. TNF-α was previously shown to stimulate System A amino acid transport in primary human trophoblasts (PHTs), however the molecular mechanisms remain unknown. In this study, we tested the hypothesis that TNF-α regulates amino acid uptake in cultured PHTs by a mitogen-activated protein kinase (MAPK)-dependent mechanism. Treatment of PHTs with TNF-α significantly increased System A amino acid transport, as well as Erk and p38 MAPK signaling. Pharmacological antagonism of p38, but not Erk MAPK activity, inhibited TNF-α stimulated System A activity. Silencing of p38 MAPK using siRNA transfections prevented TNF-α stimulated System A transport in PHTs. TNF-α significantly increased the protein expression of System A transporters SNAT1 and SNAT2, but did not affect their mRNA expression. The effects of TNF-α on SNAT1 and SNAT2 protein expression were reversed by p38 MAPK siRNA silencing. In conclusion, TNF-α regulates System A activity through increased SNAT1 and SNAT2 transporter protein expression in PHTs. These findings suggest that p38 MAPK may represent a critical mechanistic link between elevated proinflammatory cytokines and increased placental amino acid transport in obese and GDM pregnancies associated with fetal overgrowth.

  9. TNF-α stimulates System A amino acid transport in primary human trophoblast cells mediated by p38 MAPK signaling.

    PubMed

    Aye, Irving L M H; Jansson, Thomas; Powell, Theresa L

    2015-10-01

    Maternal obesity and gestational diabetes mellitus (GDM) increase the risk of delivering infants that are large for gestational age with greater adiposity, who are prone to the development of metabolic disease in childhood and beyond. These maternal conditions are also associated with increased levels of the proinflammatory cytokine TNF-α in maternal tissues and the placenta. Recent evidence suggests that changes in placental amino acid transport contribute to altered fetal growth. TNF-α was previously shown to stimulate System A amino acid transport in primary human trophoblasts (PHTs), however the molecular mechanisms remain unknown. In this study, we tested the hypothesis that TNF-α regulates amino acid uptake in cultured PHTs by a mitogen-activated protein kinase (MAPK)-dependent mechanism. Treatment of PHTs with TNF-α significantly increased System A amino acid transport, as well as Erk and p38 MAPK signaling. Pharmacological antagonism of p38, but not Erk MAPK activity, inhibited TNF-α stimulated System A activity. Silencing of p38 MAPK using siRNA transfections prevented TNF-α stimulated System A transport in PHTs. TNF-α significantly increased the protein expression of System A transporters SNAT1 and SNAT2, but did not affect their mRNA expression. The effects of TNF-α on SNAT1 and SNAT2 protein expression were reversed by p38 MAPK siRNA silencing. In conclusion, TNF-α regulates System A activity through increased SNAT1 and SNAT2 transporter protein expression in PHTs. These findings suggest that p38 MAPK may represent a critical mechanistic link between elevated proinflammatory cytokines and increased placental amino acid transport in obese and GDM pregnancies associated with fetal overgrowth. PMID:26508738

  10. p38 MAPK Regulates Cavitation and Tight Junction Function in the Mouse Blastocyst

    PubMed Central

    Bell, Christine E.; Watson, Andrew J.

    2013-01-01

    Blastocyst formation is essential for implantation and maintenance of pregnancy and is dependent on the expression and coordinated function of a series of proteins involved in establishing and maintaining the trans-trophectoderm ion gradient that enables blastocyst expansion. These consist of Na/K-ATPase, adherens junctions, tight junctions (TJ) and aquaporins (AQP). While their role in supporting blastocyst formation is established, the intracellular signaling pathways that coordinate their function is unclear. The p38 MAPK pathway plays a role in regulating these proteins in other cell types and is required for embryo development at the 8–16 cell stage, but its role has not been investigated in the blastocyst. Hypothesis p38 MAPK regulates blastocyst formation by regulating blastocyst formation gene expression and function. Methods Embryos were cultured from the early blastocyst stage for 12 h or 24 h in the presence of a potent and specific p38 MAPK inhibitor, SB 220025. Blastocyst expansion, hatching, gene family expression and localization, TJ function and apoptosis levels were analyzed. Results Inhibition of the p38 MAPK pathway reduced blastocyst expansion and hatching, increased tight junction permeability, affected TJP1 localization, reduced Aqp3 expression, and induced a significant increase in apoptosis. Conclusion The p38 MAPK pathway coordinates the overall events that regulate blastocyst formation. PMID:23593143

  11. Klotho Protects Dopaminergic Neuron Oxidant-Induced Degeneration by Modulating ASK1 and p38 MAPK Signaling Pathways

    PubMed Central

    Brobey, Reynolds K.; German, Dwight; Sonsalla, Patricia K.; Gurnani, Prem; Pastor, Johanne; Hsieh, C-C; Papaconstantinou, John; Foster, Philip P.; Kuro-o, Makoto; Rosenblatt, Kevin P.

    2015-01-01

    Klotho transgenic mice exhibit resistance to oxidative stress as measured by their urinal levels of 8-hydroxy-2-deoxyguanosine, albeit this anti-oxidant defense mechanism has not been locally investigated in the brain. Here, we tested the hypothesis that the reactive oxygen species (ROS)-sensitive apoptosis signal-regulating kinase 1 (ASK1)/p38 MAPK pathway regulates stress levels in the brain of these mice and showed that: 1) the ratio of free ASK1 to thioredoxin (Trx)-bound ASK1 is relatively lower in the transgenic brain whereas the reverse is true for the Klotho knockout mice; 2) the reduced p38 activation level in the transgene corresponds to higher level of ASK1-bound Trx, while the KO mice showed elevated p38 activation and lower level of–bound Trx; and 3) that 14-3-3ζ is hyper phosphorylated (Ser-58) in the transgene which correlated with increased monomer forms. In addition, we evaluated the in vivo robustness of the protection by challenging the brains of Klotho transgenic mice with a neurotoxin, MPTP and analyzed for residual neuron numbers and integrity in the substantia nigra pars compacta. Our results show that Klotho overexpression significantly protects dopaminergic neurons against oxidative damage, partly by modulating p38 MAPK activation level. Our data highlight the importance of ASK1/p38 MAPK pathway in the brain and identify Klotho as a possible anti-oxidant effector. PMID:26452228

  12. Tissue-specific up-regulation of arginase I and II induced by p38 MAPK mediates endothelial dysfunction in type 1 diabetes mellitus

    PubMed Central

    Pernow, J; Kiss, A; Tratsiakovich, Y; Climent, B

    2015-01-01

    Background and Purpose Emerging evidence suggests a selective up-regulation of arginase I in diabetes causing coronary artery disease; however, the mechanisms behind this up-regulation are still unknown. Activated p38 MAPK has been reported to increase arginase II in various cardiovascular diseases. We therefore tested the role of p38 MAPK in the regulation of arginase I and II expression and its effect on endothelial dysfunction in diabetes mellitus. Experimental Approach Endothelial function was determined in septal coronary (SCA), left anterior descending coronary (LAD) and mesenteric (MA) arteries from healthy and streptozotocin-induced diabetic Wistar rats by wire myographs. Arginase activity and protein levels of arginase I, II, phospho-p38 MAPK and phospho-endothelial NOS (eNOS) (Ser1177) were determined in these arteries from diabetic and healthy rats treated with a p38 MAPK inhibitor in vivo. Key Results Diabetic SCA and MA displayed impaired endothelium-dependent relaxation, which was prevented by arginase and p38 MAPK inhibition while LAD relaxation was not affected. Arginase I, phospho-p38 MAPK and eNOS protein expression was increased in diabetic coronary arteries. In diabetic MA, however, increased expression of arginase II and phospho-p38 MAPK, increased arginase activity and decreased expression of eNOS were observed. All these effects were reversed by p38 MAPK inhibition. Conclusions and Implications Diabetes-induced activation of p38 MAPK causes endothelial dysfunction via selective up-regulation of arginase I expression in coronary arteries and arginase II expression in MA. Therefore, regional differences appear to exist in the arginase isoforms contributing to endothelial dysfunction in type 1 diabetes mellitus. PMID:26140333

  13. Plakophilin-2 loss promotes TGF-β1/p38 MAPK-dependent fibrotic gene expression in cardiomyocytes.

    PubMed

    Dubash, Adi D; Kam, Chen Y; Aguado, Brian A; Patel, Dipal M; Delmar, Mario; Shea, Lonnie D; Green, Kathleen J

    2016-02-15

    Members of the desmosome protein family are integral components of the cardiac area composita, a mixed junctional complex responsible for electromechanical coupling between cardiomyocytes. In this study, we provide evidence that loss of the desmosomal armadillo protein Plakophilin-2 (PKP2) in cardiomyocytes elevates transforming growth factor β1 (TGF-β1) and p38 mitogen-activated protein kinase (MAPK) signaling, which together coordinate a transcriptional program that results in increased expression of profibrotic genes. Importantly, we demonstrate that expression of Desmoplakin (DP) is lost upon PKP2 knockdown and that restoration of DP expression rescues the activation of this TGF-β1/p38 MAPK transcriptional cascade. Tissues from PKP2 heterozygous and DP conditional knockout mouse models also exhibit elevated TGF-β1/p38 MAPK signaling and induction of fibrotic gene expression in vivo. These data therefore identify PKP2 and DP as central players in coordination of desmosome-dependent TGF-β1/p38 MAPK signaling in cardiomyocytes, pathways known to play a role in different types of cardiac disease, such as arrhythmogenic or hypertrophic cardiomyopathy. PMID:26858265

  14. Failure to Target RANKL Signaling Through p38-MAPK Results in Defective Osteoclastogenesis in the Microphthalmia Cloudy-Eyed Mutant.

    PubMed

    Carey, Heather A; Bronisz, Agnieszka; Cabrera, Jennifer; Hildreth, Blake E; Cuitiño, Maria; Fu, Qi; Ahmad, Asrar; Toribio, Ramiro E; Ostrowski, Michael C; Sharma, Sudarshana M

    2016-03-01

    The Microphthalmia-associated transcription factor (MITF) is a basic helix-loop-helix leucine zipper family factor that is essential for terminal osteoclast differentiation. Previous work demonstrates that phosphorylation of MITF by p38 MAPK downstream of Receptor Activator of NFkB Ligand (RANKL) signaling is necessary for MITF activation in osteoclasts. The spontaneous Mitf cloudy eyed (ce) allele results in production of a truncated MITF protein that lacks the leucine zipper and C-terminal end. Here we show that the Mitf(ce) allele leads to a dense bone phenotype in neonatal mice due to defective osteoclast differentiation. In response to RANKL stimulation, in vitro osteoclast differentiation was impaired in myeloid precursors derived from neonatal or adult Mitf(ce/ce) mice. The loss of the leucine zipper domain in Mitf(ce/ce) mice does not interfere with the recruitment of MITF/PU.1 complexes to target promoters. Further, we have mapped the p38 MAPK docking site within the region deleted in Mitf(ce). This interaction is necessary for the phosphorylation of MITF by p38 MAPK. Site-directed mutations in the docking site interfered with the interaction between MITF and its co-factors FUS and BRG1. MITF-ce fails to recruit FUS and BRG1 to target genes, resulting in decreased expression of target genes and impaired osteoclast function. These results highlight the crucial role of signaling dependent MITF/p38 MAPK interactions in osteoclast differentiation.

  15. Plakophilin-2 loss promotes TGF-β1/p38 MAPK-dependent fibrotic gene expression in cardiomyocytes

    PubMed Central

    Dubash, Adi D.; Kam, Chen Y.; Aguado, Brian A.; Patel, Dipal M.; Delmar, Mario; Shea, Lonnie D.

    2016-01-01

    Members of the desmosome protein family are integral components of the cardiac area composita, a mixed junctional complex responsible for electromechanical coupling between cardiomyocytes. In this study, we provide evidence that loss of the desmosomal armadillo protein Plakophilin-2 (PKP2) in cardiomyocytes elevates transforming growth factor β1 (TGF-β1) and p38 mitogen-activated protein kinase (MAPK) signaling, which together coordinate a transcriptional program that results in increased expression of profibrotic genes. Importantly, we demonstrate that expression of Desmoplakin (DP) is lost upon PKP2 knockdown and that restoration of DP expression rescues the activation of this TGF-β1/p38 MAPK transcriptional cascade. Tissues from PKP2 heterozygous and DP conditional knockout mouse models also exhibit elevated TGF-β1/p38 MAPK signaling and induction of fibrotic gene expression in vivo. These data therefore identify PKP2 and DP as central players in coordination of desmosome-dependent TGF-β1/p38 MAPK signaling in cardiomyocytes, pathways known to play a role in different types of cardiac disease, such as arrhythmogenic or hypertrophic cardiomyopathy. PMID:26858265

  16. Failure to Target RANKL Signaling Through p38-MAPK Results in Defective Osteoclastogenesis in the Microphthalmia Cloudy-Eyed Mutant.

    PubMed

    Carey, Heather A; Bronisz, Agnieszka; Cabrera, Jennifer; Hildreth, Blake E; Cuitiño, Maria; Fu, Qi; Ahmad, Asrar; Toribio, Ramiro E; Ostrowski, Michael C; Sharma, Sudarshana M

    2016-03-01

    The Microphthalmia-associated transcription factor (MITF) is a basic helix-loop-helix leucine zipper family factor that is essential for terminal osteoclast differentiation. Previous work demonstrates that phosphorylation of MITF by p38 MAPK downstream of Receptor Activator of NFkB Ligand (RANKL) signaling is necessary for MITF activation in osteoclasts. The spontaneous Mitf cloudy eyed (ce) allele results in production of a truncated MITF protein that lacks the leucine zipper and C-terminal end. Here we show that the Mitf(ce) allele leads to a dense bone phenotype in neonatal mice due to defective osteoclast differentiation. In response to RANKL stimulation, in vitro osteoclast differentiation was impaired in myeloid precursors derived from neonatal or adult Mitf(ce/ce) mice. The loss of the leucine zipper domain in Mitf(ce/ce) mice does not interfere with the recruitment of MITF/PU.1 complexes to target promoters. Further, we have mapped the p38 MAPK docking site within the region deleted in Mitf(ce). This interaction is necessary for the phosphorylation of MITF by p38 MAPK. Site-directed mutations in the docking site interfered with the interaction between MITF and its co-factors FUS and BRG1. MITF-ce fails to recruit FUS and BRG1 to target genes, resulting in decreased expression of target genes and impaired osteoclast function. These results highlight the crucial role of signaling dependent MITF/p38 MAPK interactions in osteoclast differentiation. PMID:26218069

  17. All-Trans Retinoic Acid Induces TGF-β2 in Intestinal Epithelial Cells via RhoA- and p38α MAPK-Mediated Activation of the Transcription Factor ATF2

    PubMed Central

    Namachivayam, Kopperuncholan; MohanKumar, Krishnan; Arbach, Dima; Jagadeeswaran, Ramasamy; Jain, Sunil K.; Natarajan, Viswanathan; Mehta, Dolly; Jankov, Robert P.; Maheshwari, Akhil

    2015-01-01

    Objective We have shown previously that preterm infants are at risk of necrotizing enterocolitis (NEC), an inflammatory bowel necrosis typically seen in infants born prior to 32 weeks’ gestation, because of the developmental deficiency of transforming growth factor (TGF)-β2 in the intestine. The present study was designed to investigate all-trans retinoic acid (atRA) as an inducer of TGF-β2 in intestinal epithelial cells (IECs) and to elucidate the involved signaling mechanisms. Methods AtRA effects on intestinal epithelium were investigated using IEC6 cells. TGF-β2 expression was measured using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) and Western blots. Signaling pathways were investigated using Western blots, transiently-transfected/transduced cells, kinase arrays, chromatin immunoprecipitation, and selective small molecule inhibitors. Results AtRA-treatment of IEC6 cells selectively increased TGF-β2 mRNA and protein expression in a time- and dose-dependent fashion, and increased the activity of the TGF-β2 promoter. AtRA effects were mediated via RhoA GTPase, Rho-associated, coiled-coil-containing protein kinase 1 (ROCK1), p38α MAPK, and activating transcription factor (ATF)-2. AtRA increased phospho-ATF2 binding to the TGF-β2 promoter and increased histone H2B acetylation in the TGF-β2 nucleosome, which is typically associated with transcriptional activation. Conclusions AtRA induces TGF-β2 expression in IECs via RhoA- and p38α MAPK-mediated activation of the transcription factor ATF2. Further studies are needed to investigate the role of atRA as a protective/therapeutic agent in gut mucosal inflammation. PMID:26225425

  18. 16-hydroxy-cleroda-3,13-dien-16,15-olide induced glioma cell autophagy via ROS generation and activation of p38 MAPK and ERK-1/2.

    PubMed

    Thiyagarajan, Varadharajan; Sivalingam, Kalai Selvi; Viswanadha, Vijaya Padma; Weng, Ching-Feng

    2016-07-01

    16-hydroxy-cleroda-3,13-dien-16,15-olide (HCD), a natural product isolated from medicinal plant Polyalthia longifolia exhibits anticancer activity through caspase-independent apoptosis in brain tumors, as previously reported. This study further attempted to investigate the involvement of HCD-induced autophagy in brain tumor cell lines neuroblastoma N18 and glioma C6 through the induction of reactive oxygen species (ROS) and the activation of p38 and ERK-1/2 pathway. The results demonstrated that HCD increased the hyper-generation of ROS and decreased cellular antioxidant enzymes, such as superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and glutathione s transferase (GST). Furthermore, HCD increased the expressions of autophagic marker proteins LC3-II and Beclin-1 in a time- and dose-dependent manner. Additionally, HCD was found to significantly induce p-p38 MAPK and p-ERK-1/2 proteins by Western blot, which implies that HCD is a potential therapeutic anticancer agent that exerts its activity through inducing ROS-mediation for the autophagy of brain tumor cells.

  19. Polyacrylic acid-coated and non-coated iron oxide nanoparticles induce cytokine activation in human blood cells through TAK1, p38 MAPK and JNK pro-inflammatory pathways.

    PubMed

    Couto, Diana; Freitas, Marisa; Porto, Graça; Lopez-Quintela, M Arturo; Rivas, José; Freitas, Paulo; Carvalho, Félix; Fernandes, Eduarda

    2015-10-01

    Iron oxide nanoparticles (ION) can have a wide scope of applications in biomedicine, namely in magnetic resonance imaging, tissue repair, drug delivery, hyperthermia, transfection, tissue soldering, and as antimicrobial agents. The safety of these nanoparticles, however, is not completely established, namely concerning their effect on immune system and inflammatory pathways. The aim of this study was to evaluate the in vitro effect of polyacrylic acid (PAA)-coated ION and non-coated ION on the production of six cytokines [interleukin 1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), interferon gamma (IFN-γ) and interleukin 10 (IL-10)] by human peripheral blood cells, and to determine the inflammatory pathways involved in this production. The obtained results showed that PAA-coated and non-coated ION were able to induce all the tested cytokines and that activation of transforming growth factor beta (TGF-β)-activated kinase (TAK1), p38 mitogen-activated protein kinases (p38 MAPK) and c-Jun N-terminal kinases (JNK) were involved in this effect. PMID:25108419

  20. Heat Shock Factor 1 Is a Substrate for p38 Mitogen-Activated Protein Kinases

    PubMed Central

    Dayalan Naidu, Sharadha; Sutherland, Calum; Zhang, Ying; Risco, Ana; de la Vega, Laureano; Caunt, Christopher J.; Hastie, C. James; Lamont, Douglas J.; Torrente, Laura; Chowdhry, Sudhir; Benjamin, Ivor J.; Keyse, Stephen M.; Cuenda, Ana

    2016-01-01

    Heat shock factor 1 (HSF1) monitors the structural integrity of the proteome. Phosphorylation at S326 is a hallmark for HSF1 activation, but the identity of the kinase(s) phosphorylating this site has remained elusive. We show here that the dietary agent phenethyl isothiocyanate (PEITC) inhibits heat shock protein 90 (Hsp90), the main negative regulator of HSF1; activates p38 mitogen-activated protein kinase (MAPK); and increases S326 phosphorylation, trimerization, and nuclear translocation of HSF1, and the transcription of a luciferase reporter, as well as the endogenous prototypic HSF1 target Hsp70. In vitro, all members of the p38 MAPK family rapidly and stoichiometrically catalyze the S326 phosphorylation. The use of stable knockdown cell lines and inhibitors indicated that among the p38 MAPKs, p38γ is the principal isoform responsible for the phosphorylation of HSF1 at S326 in cells. A protease-mass spectrometry approach confirmed S326 phosphorylation and unexpectedly revealed that p38 MAPK also catalyzes the phosphorylation of HSF1 at S303/307, previously known repressive posttranslational modifications. Thus, we have identified p38 MAPKs as highly efficient catalysts for the phosphorylation of HSF1. Furthermore, our findings suggest that the magnitude and persistence of activation of p38 MAPK are important determinants of the extent and duration of the heat shock response. PMID:27354066

  1. Long term intake of 0.1% ethanol decreases serum adiponectin by suppressing PPARγ expression via p38 MAPK pathway.

    PubMed

    Tian, Chong; Jin, Xin; Ye, Xiaolei; Wu, Hongmei; Ren, Weiye; Zhang, Rui; Long, Jia; Ying, Chenjiang

    2014-03-01

    Light alcohol consumption was reported to be negatively associated with insulin resistance and risk of cardiovascular diseases; however, the results were inconsistent. We here investigate whether long term intake of low-concentration ethanol can affect adiponectin levels. Male Wistar rats were exposed to 0.1% ethanol in drinking water for 26weeks. Visceral adipose tissue (VAT) was cultured and treated with ethanol, SB203580, GW9662, or rosiglitazone. Adiponectin in serum and culture supernatant were measured by ELISA, mRNA levels of adiponectin and PPARγ were determined by RT-PCR, and protein expressions of PPARγ, p38 MAPK and phospho-p38 MAPK were determined by Western blot. In vivo, ethanol decreased the mRNA of adiponectin in VAT and serum adiponectin significantly. Decreased PPARγ and increased activation of p38 MAPK were observed in ethanol treated group. In vitro, SB203580 increased the adiponectin and PPARγ levels in normal DMEM cultured VAT and ameliorated ethanol-induced decrease of adiponectin and PPARγ expressions. GW9662 also decreased the adiponectin levels; Both ethanol and GW9662 weakened the rosiglitazone-induced elevation of adiponectin levels in cultured VAT. These data suggest that long term intake of 0.1% ethanol down-regulated adiponectin levels, and the regulation of PPARγ via p38 MAPK pathway plays an important role in the mechanism underneath.

  2. Cell-type specific crosstalk between p38 MAPK and Rho signaling in lung micro- and macrovascular barrier dysfunction induced by Staphylococcus aureus-derived pathogens

    PubMed Central

    Wu, Tinghuai; Xing, Junjie; Birukova, Anna A.

    2014-01-01

    Lung inflammation and alterations in endothelial cell (EC) micro- and macro-vascular permeability are key events to development of acute lung injury (ALI). Using ECs derived from human pulmonary artery (HPAECs) and lung microvasculature (HLMVECs), we investigated interplay between p38 stress MAPK and Rho GTPase signaling in the inflammatory and hyperpermeability response. Both cell types were treated with Staphylococcus aureus-derived peptidoglycan (PepG) and lipoteichoic acid (LTA) with or without pretreatment with p38 MAPK or Rho kinase inhibitors. LTA and PepG markedly increased permeability in both pulmonary macrovascular and microvascular EC. Agonist-induced hyper-permeability was accompanied by cytoskeletal remodeling, disruption of cell-cell contacts, formation of paracellular gaps, and activation of p38 MAPK, NFκB, and Rho/Rho kinase signaling. In macrovascular ECs, pharmacological inhibition of Rho kinase with Y27632 significantly suppressed p38 MAP kinase cascade activation, while inhibition of p38 MAPK with SB203580 had no effect on Rho activation. In contrast, inhibition of p38 MAPK in microvascular ECs suppressed LTA/PepG-induced activation of Rho, while Rho inhibitor suppressed activation of p38 MAPK. Inhibition of either p38 MAPK or Rho kinase substantially attenuated activation of NFκB signaling. These results demonstrate cell type-specific differences in signaling induced by Staphylococcus aureus-derived pathogens in pulmonary endothelium. Thus, although Gram-positive bacterial compounds caused barrier dysfunction in both EC types, it was induced by different pattern of crosstalk between Rho, p38 MAPK, and NFκB signaling. These observations may have important implications in defining microvasculature-specific therapeutic strategies aimed at the treatment of sepsis and acute lung injury induced by Gram-positive bacterial pathogens. PMID:23571093

  3. p38 MAPK is a likely component of the signal transduction pathway triggering rapid cold hardening in the flesh fly Sarcophaga crassipalpis.

    PubMed

    Fujiwara, Yoshihiro; Denlinger, David L

    2007-09-01

    Rapid cold hardening (RCH) is an adaptation enabling insects to quickly respond to low temperature, but little is known about the molecular events that trigger this response. In this study of the flesh fly Sarcophaga crassipalpis, we explore a possible role for mitogen-activated protein kinases (MAPKs) in the low temperature signaling that elicits RCH. We report that p38 MAPK from S. crassipalpis, which shows high cDNA sequence homology to p38 MAPKs from other insects and mammals, is rapidly activated at temperatures around 0 degrees C, temperatures that are most effective for inducing RCH. By contrast, low temperature does not activate either extracellular signal-regulated kinase (ERK) or Jun N-terminal kinase (JNK). An increase in phospho-p38 MAPK was observed within 10 min following exposure to 0 degrees C and reached its maximum level in 2 h. When flies were transferred from 0 to 25 degrees C, the level of phospho-p38 MAPK decreased immediately and reached trace levels by 3 h. Nondiapausing flies were much more responsive to p38 MAPK activation than cold-hardy diapausing pupae. Thus, p38 MAPK activation and RCH both show the same narrow ranges of temperature sensitivity, temporal profiles of activation and decay, and developmental specificity. These correlations suggest that p38 MAPK plays a potential role in regulating the induction of RCH. The p38 MAPK response was not dependent upon the brain, as evidenced by high activation in isolated abdomens exposed to low temperature. PMID:17766307

  4. Antagonistic roles of the ERK and p38 MAPK signalling pathways in globin expression, haem biosynthesis and iron uptake.

    PubMed

    Mardini, Louay; Gasiorek, Jadwiga; Derjuga, Anna; Carrière, Lucie; Schranzhofer, Matthias; Paw, Barry H; Ponka, Prem; Blank, Volker

    2010-11-15

    Late-stage erythroid cells synthesize large quantities of haemoglobin, a process requiring the co-ordinated regulation of globin and haem synthesis as well as iron uptake. In the present study, we investigated the role of the ERK (extracellular-signal-regulated kinase) and p38 MAPK (mitogen-activated protein kinase) signalling pathways in MEL (mouse erythroleukaemia) cell differentiation. We found that treatment of HMBA (hexamethylene bisacetamide)-induced MEL cells with the ERK pathway inhibitor UO126 results in an increase in intracellular haem and haemoglobin levels. The transcript levels of the genes coding for β(major)-globin, the haem biosynthesis enzyme 5-aminolevulinate synthase 2 and the mitochondrial iron transporter mitoferrin 1 are up-regulated. We also showed enhanced expression of globin and transferrin receptor 1 proteins upon UO126 treatment. With respect to iron uptake, we found that ERK inhibitor treatment led to an increase in both haem-bound and total iron. In contrast, treatment of MEL cells with the p38 MAPK pathway inhibitor SB202190 had the opposite effect, resulting in decreased globin expression, haem synthesis and iron uptake. Reporter assays showed that globin promoter and HS2 enhancer-mediated transcription was under the control of MAPKs, as inhibition of the ERK and p38 MAPK pathways led to increased and decreased gene activity respectively. Our present results suggest that the ERK1/2 and p38α/β MAPKs play antagonistic roles in HMBA-induced globin gene expression and erythroid differentiation. These results provide a novel link between MAPK signalling and the regulation of haem biosynthesis and iron uptake in erythroid cells.

  5. p38γ MAPK Is a Therapeutic Target for Triple-Negative Breast Cancer by Stimulation of Cancer Stem-Like Cell Expansion.

    PubMed

    Qi, Xiaomei; Yin, Ning; Ma, Shao; Lepp, Adrienne; Tang, Jun; Jing, Weiqing; Johnson, Bryon; Dwinell, Michael B; Chitambar, Christopher R; Chen, Guan

    2015-09-01

    Triple-negative breast cancer (TNBC) is highly progressive and lacks established therapeutic targets. p38γ mitogen-activated protein kinase (MAPK) (gene name: MAPK12) is overexpressed in TNBC but how overexpressed p38γ contributes to TNBC remains unknown. Here, we show that p38γ activation promotes TNBC development and progression by stimulating cancer stem-like cell (CSC) expansion and may serve as a novel therapeutic target. p38γ silencing in TNBC cells reduces mammosphere formation and decreases expression levels of CSC drivers including Nanog, Oct3/4, and Sox2. Moreover, p38γ MAPK-forced expression alone is sufficient to stimulate CSC expansion and to induce epithelial cell transformation in vitro and in vivo. Furthermore, p38γ depends on its activity to stimulate CSC expansion and breast cancer progression, indicating a therapeutic opportunity by application of its pharmacological inhibitor. Indeed, the non-toxic p38γ specific pharmacological inhibitor pirfenidone selectively inhibits TNBC growth in vitro and/or in vivo and significantly decreases the CSC population. Mechanistically, p38γ stimulates Nanog transcription through c-Jun/AP-1 via a multi-protein complex formation. These results together demonstrate that p38γ can drive TNBC development and progression and may be a novel therapeutic target for TNBC by stimulating CSC expansion. Inhibiting p38γ activity with pirfenidone may be a novel strategy for the treatment of TNBC.

  6. Differential roles of p38-MAPK and JNKs in mediating early protection or apoptosis in the hyperthermic perfused amphibian heart.

    PubMed

    Gaitanaki, Catherine; Mastri, Michalis; Aggeli, Ioanna-Katerina S; Beis, Isidoros

    2008-08-01

    In the present study the activation of p38 mitogen-activated protein kinase (p38-MAPK) and c-Jun N-terminal kinases (JNKs) by hyperthermia was investigated in the isolated perfused Rana ridibunda heart. Hyperthermia (42 degrees C) was found to profoundly stimulate p38-MAPK phosphorylation within 0.5 h, with maximal values being attained at 1 h [4.503(+/-0.577)-fold relative to control, P<0.01]. JNKs were also activated under these conditions in a sustained manner for at least 4 h [2.641(+/-0.217)-fold relative to control, P<0.01]. Regarding their substrates, heat shock protein 27 (Hsp27) was maximally phosphorylated at 1 h [2.261(+/-0.327)-fold relative to control, P<0.01] and c-Jun at a later phase [3 h: 5.367(+/-0.081)-fold relative to control, P<0.001]. Hyperthermia-induced p38-MAPK activation was found to be dependent on the Na+/H+ exchanger 1 (NHE1) and was also suppressed by catalase (Cat) and superoxide dismutase (SOD), implicating the generation of reactive oxygen species (ROS). ROS were also implicated in the activation of JNKs by hyperthermia, with the Na+/K+-ATPase acting as a mediator of this effect at an early stage and the NHE1 getting involved at a later time point. Finally, JNKs were found to be the principal mediators of the apoptosis induced under hyperthermic conditions, as their inhibition abolished poly(ADP-ribose) polymerase (PARP) cleavage after 4 h at 42 degrees C. Overall, to our knowledge, this study highlights for the first time the variable mediators implicated in the transduction of the hyperthermic signal in the isolated perfused heart of an ectotherm and deciphers a potential salutary effect of p38-MAPK as well as the fundamental role of JNKs in the induced apoptosis.

  7. Regulation of Muscle Stem Cell Functions: A Focus on the p38 MAPK Signaling Pathway

    PubMed Central

    Segalés, Jessica; Perdiguero, Eusebio; Muñoz-Cánoves, Pura

    2016-01-01

    Formation of skeletal muscle fibers (myogenesis) during development and after tissue injury in the adult constitutes an excellent paradigm to investigate the mechanisms whereby environmental cues control gene expression programs in muscle stem cells (satellite cells) by acting on transcriptional and epigenetic effectors. Here we will review the molecular mechanisms implicated in the transition of satellite cells throughout the distinct myogenic stages (i.e., activation from quiescence, proliferation, differentiation, and self-renewal). We will also discuss recent findings on the causes underlying satellite cell functional decline with aging. In particular, our review will focus on the epigenetic changes underlying fate decisions and on how the p38 MAPK signaling pathway integrates the environmental signals at the chromatin to build up satellite cell adaptive responses during the process of muscle regeneration, and how these responses are altered in aging. A better comprehension of the signaling pathways connecting external and intrinsic factors will illuminate the path for improving muscle regeneration in the aged.

  8. The effect of p38MAPK on cyclic stretch in human facial hypertrophic scar fibroblast differentiation.

    PubMed

    Du, Qi-cui; Zhang, Dai-zun; Chen, Xiu-juan; Lan-Sun, Gui; Wu, Min; Xiao, Wen-lin

    2013-01-01

    Hypertrophic scars (HTS), the excessive deposition of scar tissue by fibroblasts, is one of the most common skin disorders. Fibroblasts derived from surgical scar tissue produce high levels of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1). However, the molecular mechanisms for this phenomenon is poorly understood. Thus, the purpose of this study was to evaluate the molecular mechanisms of HTS and their potential therapeutic implications. Fibroblasts derived from skin HTS were cultured and characterized in vitro. The fibroblasts were synchronized and randomly assigned to two groups: cyclic stretch and cyclic stretch pre-treated with SB203580 (a p38MAPK inhibitor). Cyclic stretch at 10% strain was applied at a loading frequency of 10 cycles per minute (i.e. 5 seconds of tension and 5 seconds of relaxation) for 0 h, 6 h and 12 h. Cyclic stretch on HTS fibroblasts led to an increase in the expression of α-SMA and TGF-β1 mRNA and protein and the phosphorylation of p38MAPK. SB203580 reversed these effects and caused a decrease in matrix contraction. Furthermore, HTS fibroblast growth was partially blocked by p38MAPK inhibition. Therefore, the mechanism of cyclic stretch involves p38 MAPK, and its inhibition is suggested as a novel therapeutic strategy for HTS.

  9. From Enzyme to Whole Blood: Sequential Screening Procedure for Identification and Evaluation of p38 MAPK Inhibitors.

    PubMed

    Bauer, Silke M; Kubiak, Jakub M; Rothbauer, Ulrich; Laufer, Stefan

    2016-01-01

    p38 mitogen-activated protein kinase (MAPK) is a pivotal enzyme in the biosynthesis of pro-inflammatory cytokines like IL-1 and TNF. Therefore, the success of anti-cytokine therapy for treatment of inflammatory processes qualified p38-MAPK as a solid target in drug research concerning chronic inflammatory diseases including infectious vascular, neurobiological, and autoimmune disorders. However, the discovery of new kinase inhibitors is limited by the need for a high biological activity combined with restricted activity to the target enzyme or pathway interaction. As a consequence, no p38 MAPK inhibitor has been introduced to the market so far, although several p38 inhibitors have proceeded into clinical trials. The development of novel inhibitor types and optimization of already known structural classes of MAPK inhibitors require appropriate testing systems reaching across these crucial parameters. As a new approach, we describe the sequential arrangement of three testing systems custom-tailored to the requirements of drug discovery programs with focus on p38 inhibition. Integrated analysis of the obtained results enables a concerted step-by-step selection of tested molecules in order to screen a compound library for the most suitable inhibitor. First, evaluation of the inhibitor's activity on the isolated p38 MAPK enzyme via an ELISA assay gives a first idea about the inhibitory potency of the molecule. Moreover, structure-activity relationships can be elucidated when comparing molecules within inhibitor series. Second, screening in living cells via a p38 substrate-specific MK2-EGFP translocation assay supplies further information about efficacy, but provides also a first notion concerning selectivity and toxicity. Third, efficacy is evaluated more specifically in vivo in LPS-stimulated human whole blood with regard to in vivo parameters, e.g., pharmacokinetic characteristics like plasma protein binding and cellular permeability. These three testing systems

  10. From Enzyme to Whole Blood: Sequential Screening Procedure for Identification and Evaluation of p38 MAPK Inhibitors.

    PubMed

    Bauer, Silke M; Kubiak, Jakub M; Rothbauer, Ulrich; Laufer, Stefan

    2016-01-01

    p38 mitogen-activated protein kinase (MAPK) is a pivotal enzyme in the biosynthesis of pro-inflammatory cytokines like IL-1 and TNF. Therefore, the success of anti-cytokine therapy for treatment of inflammatory processes qualified p38-MAPK as a solid target in drug research concerning chronic inflammatory diseases including infectious vascular, neurobiological, and autoimmune disorders. However, the discovery of new kinase inhibitors is limited by the need for a high biological activity combined with restricted activity to the target enzyme or pathway interaction. As a consequence, no p38 MAPK inhibitor has been introduced to the market so far, although several p38 inhibitors have proceeded into clinical trials. The development of novel inhibitor types and optimization of already known structural classes of MAPK inhibitors require appropriate testing systems reaching across these crucial parameters. As a new approach, we describe the sequential arrangement of three testing systems custom-tailored to the requirements of drug discovery programs with focus on p38 inhibition. Integrated analysis of the obtained results enables a concerted step-by-step selection of tested molecules in order to screen a compound library for the most suitable inhibitor. First, evaluation of the inhibitor's activity on the isolated p38 MAPK enzyme via an ELISA assay gives a first idea about the inhibitory potency of the molecule. Moreover, structure-activity relationships can be elucidated when comparing molecules within inhibitor series. Second, screening in living cells via a p38 substrate-specific MK2-EGFP translocation assay supplies further information about efficacy, but provides also a first notion concerning selectivity and toxicity. Third, efficacy is evaluated more specifically in vivo in LPS-stimulated human whole blood with regard to in vivo parameters, e.g., pharmacokinetic characteristics like plasma protein binding and cellular permeability. These three testing systems

  11. Death receptor-3, a new E-Selectin counter-receptor that confers migration and survival advantages to colon carcinoma cells by triggering p38 and ERK MAPK activation.

    PubMed

    Gout, Stéphanie; Morin, Chantale; Houle, François; Huot, Jacques

    2006-09-15

    E-selectin-mediated adhesion of colon cancer cells to endothelial cells is a key event in metastasis. However, the signaling mechanisms that confer metastatic advantages to cancer cells adhering to E-selectin are ill defined. By using affinity column chromatography and pull-down assays on purified membrane extracts of HT29 and LoVo cells coupled to mass spectrometry analysis, we obtained the first evidence indicating that E-selectin binds to death receptor-3 (DR3) expressed by the cancer cells. Thereafter, we accumulated several results, suggesting that DR3 is an E-selectin receptor on colon cancer cells and that its activation by E-selectin triggers the activation of p38 and extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) and confers migration and survival advantages. First, by Western blotting, we found that the E-selectin-binding protein, identified as DR3, is recognized by two anti-DR3 antibodies. Second, the neutralization of DR3 with an antibody and its knockdown by small interfering RNA decrease the adhesion of colon cancer cells to E-selectin and E-selectin-expressing human umbilical vein endothelial cells. Third, inhibiting DR3 and knocking down its expression impair transendothelial migration of HT29 cells and block the activation of p38 and ERK by E-selectin. Fourth, high molecular weight isoforms of DR3 are expressed in samples of primary human colon carcinoma but not in samples from normal colon tissue. Intriguingly, DR3 is a death receptor but its activation by E-selectin does not induce apoptosis in colon cancer cells, except when ERK is inhibited. Our findings identify novel signaling and functional roles of DR3 activated in response to E-selectin and highlight the potential link between DR3 and metastasis. PMID:16982754

  12. The suppressive role of p38 MAPK in cellular vacuole formation.

    PubMed

    Chen, Run; Duan, Chun-Yan; Chen, Shao-Kun; Zhang, Chun-Yan; He, Tao; Li, Hong; Liu, You-Ping; Dai, Rong-Yang

    2013-08-01

    Vacuolization of the cytoplasm is one of the dramatic and frequently observed phenomena in various cell types. Cellular vacuoles occur spontaneously or via a wide range of inductive stimuli, but the molecular mechanism involved in this process remains largely unknown. In this study, we investigated the role of the p38 and JNK pathways in the formation of cytoplasmic vacuoles. We found that p38 and JNK agonist anisomycin abolishes spontaneous cytoplasmic vacuolization of HepG2 cells through p38 activation, but not through JNK activation. Importantly, blocking the activity of p38 or suppression the expression of p38 elicits cytoplasmic vacuoles formation in various cancer cells. Furthermore, cytoplasmic vacuoles induced by p38 blocking are derived from the perinuclear region. These observations provide direct evidence for a role of p38 signaling in regulating the formation of cytoplasmic vacuoles.

  13. Morphine Suppresses Tumor Angiogenesis through a HIF-1α/p38MAPK Pathway

    PubMed Central

    Koodie, Lisa; Ramakrishnan, Sundaram; Roy, Sabita

    2010-01-01

    Morphine, a highly potent analgesic agent, is frequently prescribed for moderate to severe cancer pain. In this study, morphine was administered at a clinically relevant analgesic dose to assess tumor cell-induced angiogenesis and subcutaneous tumor growth in nude mice using mouse Lewis lung carcinoma cells (LLCs). Implantation of mice with a continuous slow-release morphine pellet achieved morphine plasma levels within 250–400 ng/ml (measured using a radioimmunoassay, Coat-A-Count Serum Morphine) and was sufficient to significantly reduce tumor cell-induced angiogenesis and tumor growth when compared with placebo treatment. Morphometric analysis for blood vessel formation further confirmed that morphine significantly reduced blood vessel density (P < 0.003), vessel branching (P < 0.05), and vessel length (P < 0.002) when compared with placebo treatment. Morphine’s effect was abolished in mice coadministered the classical opioid receptor antagonist, naltrexone, and in mu-opioid receptor knockout mice, supporting the involvement of the classical opioid receptors in vivo. Morphine’s inhibitory effect is mediated through the suppression of the hypoxia-induced mitochondrial p38 mitogen-activated protein kinase (MAPK) pathway. Our results suggest that in vitro morphine treatment of LLCs inhibits the hypoxia-induced nuclear translocation of hypoxia-inducible transcription factor 1α to reduce vascular endothelial growth factor transcription and secretion, in a manner similar to pharmacological blockade with the p38 MAPK-specific inhibitor, SB203585. These studies indicate that morphine, in addition to its analgesic function, may be exploited for its antiangiogenic potential. PMID:20616349

  14. p38 (Mapk14/11) occupies a regulatory node governing entry into primitive endoderm differentiation during preimplantation mouse embryo development

    PubMed Central

    Thamodaran, Vasanth

    2016-01-01

    During mouse preimplantation embryo development, the classically described second cell-fate decision involves the specification and segregation, in blastocyst inner cell mass (ICM), of primitive endoderm (PrE) from pluripotent epiblast (EPI). The active role of fibroblast growth factor (Fgf) signalling during PrE differentiation, particularly in the context of Erk1/2 pathway activation, is well described. However, we report that p38 family mitogen-activated protein kinases (namely p38α/Mapk14 and p38β/Mapk11; referred to as p38-Mapk14/11) also participate in PrE formation. Specifically, functional p38-Mapk14/11 are required, during early-blastocyst maturation, to assist uncommitted ICM cells, expressing both EPI and earlier PrE markers, to fully commit to PrE differentiation. Moreover, functional activation of p38-Mapk14/11 is, as reported for Erk1/2, under the control of Fgf-receptor signalling, plus active Tak1 kinase (involved in non-canonical bone morphogenetic protein (Bmp)-receptor-mediated PrE differentiation). However, we demonstrate that the critical window of p38-Mapk14/11 activation precedes the E3.75 timepoint (defined by the initiation of the classical ‘salt and pepper’ expression pattern of mutually exclusive EPI and PrE markers), whereas appropriate lineage maturation is still achievable when Erk1/2 activity (via Mek1/2 inhibition) is limited to a period after E3.75. We propose that active p38-Mapk14/11 act as enablers, and Erk1/2 as drivers, of PrE differentiation during ICM lineage specification and segregation. PMID:27605380

  15. p38 (Mapk14/11) occupies a regulatory node governing entry into primitive endoderm differentiation during preimplantation mouse embryo development.

    PubMed

    Thamodaran, Vasanth; Bruce, Alexander W

    2016-09-01

    During mouse preimplantation embryo development, the classically described second cell-fate decision involves the specification and segregation, in blastocyst inner cell mass (ICM), of primitive endoderm (PrE) from pluripotent epiblast (EPI). The active role of fibroblast growth factor (Fgf) signalling during PrE differentiation, particularly in the context of Erk1/2 pathway activation, is well described. However, we report that p38 family mitogen-activated protein kinases (namely p38α/Mapk14 and p38β/Mapk11; referred to as p38-Mapk14/11) also participate in PrE formation. Specifically, functional p38-Mapk14/11 are required, during early-blastocyst maturation, to assist uncommitted ICM cells, expressing both EPI and earlier PrE markers, to fully commit to PrE differentiation. Moreover, functional activation of p38-Mapk14/11 is, as reported for Erk1/2, under the control of Fgf-receptor signalling, plus active Tak1 kinase (involved in non-canonical bone morphogenetic protein (Bmp)-receptor-mediated PrE differentiation). However, we demonstrate that the critical window of p38-Mapk14/11 activation precedes the E3.75 timepoint (defined by the initiation of the classical 'salt and pepper' expression pattern of mutually exclusive EPI and PrE markers), whereas appropriate lineage maturation is still achievable when Erk1/2 activity (via Mek1/2 inhibition) is limited to a period after E3.75. We propose that active p38-Mapk14/11 act as enablers, and Erk1/2 as drivers, of PrE differentiation during ICM lineage specification and segregation. PMID:27605380

  16. The Protective Effect of Beraprost Sodium on Diabetic Nephropathy by Inhibiting Inflammation and p38 MAPK Signaling Pathway in High-Fat Diet/Streptozotocin-Induced Diabetic Rats

    PubMed Central

    Peng, Li; Li, Jie; Xu, Yixing; Wang, Yangtian; Du, Hong; Shao, Jiaqing; Liu, Zhimin

    2016-01-01

    Background. p38 mitogen-activated protein kinase (MAPK) plays a crucial role in regulating signaling pathways implicated in inflammatory processes leading to diabetic nephropathy (DN). This study aimed to examine p38 MAPK activation in DN and determine whether beraprost sodium (BPS) ameliorates DN by inhibiting inflammation and p38 MAPK signaling pathway in diabetic rats. Methods. Forty male Sprague Dawley (SD) rats were randomly divided into the normal control group, type 2 diabetic group, and BPS treatment group. At the end of the 8-week experiment, we measured renal pathological changes and the activation of the p38 MAPK signaling pathway and inflammation. Result. After BPS treatment, renal function, 24-hour urine protein, lipid profiles, and blood glucose level were improved significantly; meanwhile, inflammation and the expression of p38 MAPK signaling pathway in the diabetic kidney were attenuated. Conclusions. BPS significantly prevented type 2 diabetes induced kidney injury characterized by renal dysfunction and pathological changes. The protective mechanisms are complicated but may be mainly attributed to the inhibition of the p38 MAPK signaling pathway and inflammation in the diabetic kidney. PMID:27212945

  17. Leptin inhibits the Na(+)/K(+) ATPase in Caco-2 cells via PKC and p38MAPK.

    PubMed

    El-Zein, Ola; Usta, Julnar; El Moussawi, Layla; Kreydiyyeh, Sawsan Ibrahim

    2015-03-01

    We demonstrated previously an inhibitory effect of luminal leptin on glucose absorption in differentiated Caco-2 cells. Since this process is dependent on the Na(+) gradient established by the Na(+)/K(+)ATPase this work was undertaken to investigate if the ATPase is one of the hormone's targets. Fully differentiated Caco-2 cells were incubated with 10nM luminal leptin and the activity of the Na(+)/K(+) ATPase was assayed by measuring the amount of inorganic phosphate liberated. To elucidate the signaling pathway involved, the suspected mediators, namely PKC, p38MAPK, ERK and PI3K, were inhibited with specific pharmacological inhibitors and their implication was confirmed by determining changes in the protein expression of their active phosphorylated forms by Western blot analysis. Leptin reduced significantly the activity of the Na(+)/K(+) ATPase, by activating p38MAPK via inhibition of PKC, an upstream inhibitor of the kinase. ERK and PI3K are modulators of the pump and are not along the pathway activated by leptin but cross talk with it at the level of p38MAPK.

  18. Acetylsalicylic acid enhances the anti-inflammatory effect of fluoxetine through inhibition of NF-κB, p38-MAPK and ERK1/2 activation in lipopolysaccharide-induced BV-2 microglia cells.

    PubMed

    Yang, J M; Rui, B B; Chen, C; Chen, H; Xu, T J; Xu, W P; Wei, W

    2014-09-01

    The latest advancements in neurobiological research provide increasing evidence that inflammatory and neurodegenerative pathways play an important role in depression. According to the cytokine hypothesis, depression could be due to the increased production of pro-inflammatory cytokines by microglia activation. Thus, using the BV-2 microglial cell line, the aim of the present study was to investigate whether fluoxetine (FLX) or acetylsalicylic acid (ASA) could inhibit this microglia activation and could achieve better results in combination. Our results showed that FLX could attenuate lipopolysaccharide (LPS)-induced production of interleukin-1β (IL-1β), the expression of the indoleamine 2,3 dioxygenase (IDO) enzyme and the depletion of 5-HT. Moreover, FLX could inhibit phosphorylation of nuclear factor-κB (NF-κB) and phosphorylation of p38 mitogen-activated protein kinase (MAPK), and the combined use with ASA could enhance these effects. Notably, the adjunctive agent ASA could also inhibit phosphorylation of extracellular-regulated kinase 1/2 (ERK1/2). Taken together, our results suggest that FLX may have some anti-inflammatory effects by modulating microglia activation and that ASA served as an effective adjunctive agent by enhancing these therapeutic effects.

  19. Synergistic activation of NF-{kappa}B by nontypeable H. influenzae and S. pneumoniae is mediated by CK2, IKK{beta}-I{kappa}B{alpha}, and p38 MAPK

    SciTech Connect

    Kweon, Soo-Mi |; Wang, Beinan; Rixter, Davida; Lim, Jae Hyang; Koga, Tomoaki; Ishinaga, Hajime |; Chen, L.-F.; Jono, Hirofumi; Xu Haidong |; Li, J.-D. |. E-mail: Jian-Dong_Li@urmc.rochester.edu

    2006-12-15

    In review of the past studies on NF-{kappa}B regulation, most of them have focused on investigating how NF-{kappa}B is activated by a single inducer at a time. Given the fact that, in mixed bacterial infections in vivo, multiple inflammation inducers, including both nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae, are present simultaneously, a key issue that has yet to be addressed is whether NTHi and S. pneumoniae simultaneously activate NF-{kappa}B and the subsequent inflammatory response in a synergistic manner. Here, we show that NTHi and S. pneumoniae synergistically induce NF-{kappa}B-dependent inflammatory response via activation of multiple signaling pathways in vitro and in vivo. The classical IKK{beta}-I{kappa}B{alpha} and p38 MAPK pathways are involved in synergistic activation of NF-{kappa}B via two distinct mechanisms, p65 nuclear translocation-dependent and -independent mechanisms. Moreover, casein kinase 2 (CK2) is involved in synergistic induction of NF-{kappa}B via a mechanism dependent on phosphorylation of p65 at both Ser536 and Ser276 sites. These studies bring new insights into the molecular mechanisms underlying the NF-{kappa}B-dependent inflammatory response in polymicrobial infections and may lead to development of novel therapeutic strategies for modulating inflammation in mixed infections for patients with otitis media and chronic obstructive pulmonary diseases.

  20. 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

    2016-01-01

    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

  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. 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.

  3. Molecular characterization of Helicobacter pylori VacA induction of IL-8 in U937 cells reveals a prominent role for p38MAPK in activating transcription factor-2, cAMP response element binding protein, and NF-kappaB activation.

    PubMed

    Hisatsune, Junzo; Nakayama, Masaaki; Isomoto, Hajime; Kurazono, Hisao; Mukaida, Naofumi; Mukhopadhyay, Asish K; Azuma, Takeshi; Yamaoka, Yoshio; Sap, Jan; Yamasaki, Eiki; Yahiro, Kinnosuke; Moss, Joel; Hirayama, Toshiya

    2008-04-01

    Helicobacter pylori VacA induces multiple effects on susceptible cells, including vacuolation, mitochondrial damage, inhibition of cell growth, and enhanced cyclooxygenase-2 expression. To assess the ability of H. pylori to modulate the production of inflammatory mediators, we examined the mechanisms by which VacA enhanced IL-8 production by promonocytic U937 cells, which demonstrated the greatest VacA-induced IL-8 release of the cells tested. Inhibitors of p38 MAPK (SB203580), ERK1/2 (PD98059), IkappaBalpha ((E)-3-(4-methylphenylsulfonyl)-2-propenenitrile), Ca(2+) entry (SKF96365), and intracellular Ca(2+) channels (dantrolene) blocked VacA-induced IL-8 production. Furthermore, an intracellular Ca(2+) chelator (BAPTA-AM), which inhibited VacA-activated p38 MAPK, caused a dose-dependent reduction in VacA-induced IL-8 secretion by U937 cells, implying a role for intracellular Ca(2+) in mediating activation of MAPK and the canonical NF-kappaB pathway. VacA stimulated translocation of NF-kappaBp65 to the nucleus, consistent with enhancement of IL-8 expression by activation of the NF-kappaB pathway. In addition, small interfering RNA of activating transcription factor (ATF)-2 or CREB, which is a p38MAPK substrate and binds to the AP-1 site of the IL-8 promoter, inhibited VacA-induced IL-8 production. VacA activated an IL-8 promoter containing an NF-IL-6 site, but not a mutated AP-1 or NF-kappaB site, suggesting direct involvement of the ATF-2/CREB binding region or NF-kappaB-binding regions in VacA-induced IL-8 promoter activation. Thus, in U937 cells, VacA directly increases IL-8 production by activation of the p38 MAPK via intracellular Ca(2+) release, leading to activation of the transcription factors, ATF-2, CREB, and NF-kappaB.

  4. Molecular Characterization of Helicobacter pylori VacA Induction of IL-8 in U937 Cells Reveals a Prominent Role for p38MAPK in Activating Transcription Factor-2, cAMP Response Element Binding Protein, and NF-κB Activation1

    PubMed Central

    Hisatsune, Junzo; Nakayama, Masaaki; Isomoto, Hajime; Kurazono, Hisao; Mukaida, Naofumi; Mukhopadhyay, Asish K.; Azuma, Takeshi; Yamaoka, Yoshio; Sap, Jan; Yamasaki, Eiki; Yahiro, Kinnosuke; Moss, Joel; Hirayama, Toshiya

    2012-01-01

    Helicobacter pylori VacA induces multiple effects on susceptible cells, including vacuolation, mitochondrial damage, inhibition of cell growth, and enhanced cyclooxygenase-2 expression. To assess the ability of H. pylori to modulate the production of inflammatory mediators, we examined the mechanisms by which VacA enhanced IL-8 production by promonocytic U937 cells, which demonstrated the greatest VacA-induced IL-8 release of the cells tested. Inhibitors of p38 MAPK (SB203580), ERK1/2 (PD98059), IκBα ((E)-3-(4-methylphenylsulfonyl)-2-propenenitrile), Ca2+ entry (SKF96365), and intracellular Ca2+ channels (dantrolene) blocked VacA-induced IL-8 production. Furthermore, an intracellular Ca2+ chelator (BAPTA-AM), which inhibited VacA-activated p38 MAPK, caused a dose-dependent reduction in VacA-induced IL-8 secretion by U937 cells, implying a role for intracellular Ca2+ in mediating activation of MAPK and the canonical NF-κB pathway. VacA stimulated translocation of NF-κBp65 to the nucleus, consistent with enhancement of IL-8 expression by activation of the NF-κB pathway. In addition, small interfering RNA of activating transcription factor (ATF)-2 or CREB, which is a p38MAPK substrate and binds to the AP-1 site of the IL-8 promoter, inhibited VacA-induced IL-8 production. VacA activated an IL-8 promoter containing an NF-IL-6 site, but not a mutated AP-1 or NF-κB site, suggesting direct involvement of the ATF-2/CREB binding region or NF-κB-binding regions in VacA-induced IL-8 promoter activation. Thus, in U937 cells, VacA directly increases IL-8 production by activation of the p38 MAPK via intracellular Ca2+ release, leading to activation of the transcription factors, ATF-2, CREB, and NF-κB. PMID:18354227

  5. Ghrelin Protects against Dexamethasone-Induced INS-1 Cell Apoptosis via ERK and p38MAPK Signaling

    PubMed Central

    2016-01-01

    Glucocorticoid excess induces apoptosis of islet cells, which may result in diabetes. In this study, we investigated the protective effect of ghrelin on dexamethasone-induced INS-1 cell apoptosis. Our data showed that ghrelin (0.1 μM) inhibited dexamethasone-induced (0.1 μM) apoptosis of INS-1 cells and facilitated cell proliferation. Moreover, ghrelin upregulated Bcl-2 expression, downregulated Bax expression, and decreased caspase-3 activity. The protective effect of ghrelin against dexamethasone-induced INS-1 cell apoptosis was mediated via growth hormone secretagogue receptor 1a. Further studies revealed that ghrelin increased ERK activation and decreased p38MAPK expression after dexamethasone treatment. Ghrelin-mediated protection of dexamethasone-induced apoptosis of INS-1 cells was attenuated using the ERK inhibitor U0126 (10 μM), and cell viability increased using the p38MAPK inhibitor SB203580 (10 μM). In conclusion, ghrelin could protect against dexamethasone-induced INS-1 cell apoptosis, at least partially via GHS-R1a and the signaling pathway of ERK and p38MAPK. PMID:27190513

  6. BMP-2-enhanced chondrogenesis involves p38 MAPK-mediated down-regulation of Wnt-7a pathway.

    PubMed

    Jin, Eun-Jung; Lee, Sun-Young; Choi, Young-Ae; Jung, Jae-Chang; Bang, Ok-Sun; Kang, Shin-Sung

    2006-12-31

    The bone morphogenetic protein (BMP) family has been implicated in control of cartilage development. Here, we demonstrate that BMP-2 promotes chondrogenesis by activating p38 mitogen-activated protein kinase (MAPK), which in turn downregulates Wnt-7a/b-catenin signaling responsible for proteasomal degradation of Sox9. Exposure of mesenchymal cells to BMP-2 resulted in upregulation of Sox9 protein and a concomitant decrease in the level of b-catenin protein and Wnt-7a signaling. In agreement with this, the interaction of Sox9 with b-catenin was inhibited in the presence of BMP-2. Inhibition of the p38 MAPK pathway using a dominant negative mutant led to sustained Wnt-7a signaling and decreased Sox9 expression, with consequent inhibition of precartilage condensation and chondrogenic differentiation. Moreover, overexpression of b-catenin caused degradation of Sox9 via the ubiquitin/26S proteasome pathway. Our results collectively indicate that the increase in Sox9 protein resulting from downregulation of b-catenin/Wnt-7a signaling is mediated by p38 MAPK during BMP-2 induced chondrogenesis in chick wing bud mesenchymal cells. PMID:17202865

  7. 11-epi-Sinulariolide Acetate Reduces Cell Migration and Invasion of Human Hepatocellular Carcinoma by Reducing the Activation of ERK1/2, p38MAPK and FAK/PI3K/AKT/mTOR Signaling Pathways

    PubMed Central

    Lin, Jen-Jie; Su, Jui-Hsin; Tsai, Chi-Chu; Chen, Yi-Jen; Liao, Ming-Hui; Wu, Yu-Jen

    2014-01-01

    Cancer metastasis is one of the major causes of death in cancer. An active compound, 11-epi-sinulariolide acetate (11-epi-SA), isolated from the cultured soft coral Sinularia flexibilis has been examined for potential anti-cell migration and invasion effects on hepatocellular carcinoma cells (HCC). However, the molecular mechanism of anti-migration and invasion by 11-epi-SA on HCC, along with their corresponding effects, remain poorly understood. In this study, we investigated anti-migration and invasion effects and the underlying mechanism of 11-epi-SA in HA22T cells, and discovered by trans-well migration and invasion assays that 11-epi-SA provided a concentration-dependent inhibitory effect on the migration of human HCC HA22T cells. After treatment with 11-epi-SA for 24 h, there were suppressed protein levels of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and urokinase-type plasminogen activator (uPA) in HA22T cells. Meanwhile, the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and metalloproteinase-2 (TIMP-2) were increased in a concentration-dependent manner. Further investigation revealed that 11-epi-SA suppressed the phosphorylation of ERK1/2 and p38MAPK. The 11-epi-SA also suppressed the expression of the phosphorylation of FAK/PI3K/AKT/mTOR pathways. PMID:25222667

  8. Wound-induced p38MAPK-dependent histone H3 phosphorylation correlates with increased COX-2 expression in enterocytes.

    PubMed

    Karrasch, Thomas; Steinbrecher, Kris A; Allard, Brigitte; Baldwin, Albert S; Jobin, Christian

    2006-06-01

    Gastrointestinal epithelial cell damage triggers an important biological response called restitution, a process aimed at re-epithelializing the wounded areas. Unfortunately, little is known about the intrinsic molecular signaling events implicated in this host response. We hypothesized that wounding intestinal epithelial cells activates signaling pathways leading to chromatin modification and COX-2 upregulation during restitution. Confluent rat IEC18 cells were mechanically wounded by multiple parallel scratches using a pipet tip. NF-kappaB(Ser536), p38, and histone H3(Ser10) (H3S10) phosphorylation were determined by Western blot using specific phospho-antibodies. COX-2 gene expression was evaluated by RT-PCR, Western Blot, and ELISA. Association of phosphorylated H3, RelA (NF-kappaB), and RNA polymerase II to the COX-2 gene promoter was evaluated by chromatin immunoprecipitation (ChIP). The specific inhibitors Bay11-7082 and SB239063 as well as Ad5IkappaB-superrepressor (Ad5IkappaBAA) and Ad5dnp38 were used to block NF-kappaB- and p38-signaling pathways, respectively. Wounding induced a rapid and sustained (24 h) phosphorylation of RelAS536, H3S10, and p38MAPK in enterocytes. ChIP analysis of the COX-2 gene promoter demonstrated the presence of phospho-H3S10 and recruitment of RelA and RNA polymerase II, a process blocked by SB239063. Finally, molecular blockade of NF-kappaB (Ad5IkappaBAA) or p38MAPK (Ad5dnp38) signaling strongly inhibited enterocyte restitution. p38MAPK-dependent histone 3 phosphorylation is an important component of the intestinal wound-healing response. Targeting-signaling pathways selectively involved in healing/restitution may provide a novel means to maintain or re-establish host intestinal barrier integrity.

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

    SciTech Connect

    Wazir, Romel; Luo, De-Yi; Dai, Yi; Yue, Xuan; Tian, Ye; Wang, Kun-Jie

    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%, 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.

  10. Evaluation of proinflammatory cytokine pathway inhibitors for p38 MAPK inhibitory potential.

    PubMed

    Kadam, Rameshwar U; Garg, Divita; Paul, Atish T; Bhutani, K K; Roy, Nilanjan

    2007-12-13

    The target for the anti-inflammatory natural products like amentoflavone ( 2), which act by interfering with the proinflammatory cytokine pathway (e.g., TNF-alpha, IL-1beta, and NO synthase), is not yet well-defined. Data obtained from docking, electronic, and surface analyses shed some light on steric and electronic complementarity of these molecules to p38 MAPK, thereby suggesting a possible mechanism by which they might reduce the production of proinflammatory cytokines. PMID:17988083

  11. Reduced beta 2 glycoprotein I improves diabetic nephropathy via inhibiting TGF-β1-p38 MAPK pathway

    PubMed Central

    Wang, Tong; Chen, Si-Si; Chen, Rui; Yu, De-Min; Yu, Pei

    2015-01-01

    Purpose: Beta 2 glycoprotein I (β2GPI) has been shown the positive effect on diabetic atherosclerosis and retinal neovascularization. β2GPI can be reduced by thioredoxin-1, resulting in the reduced state of β2GPI. The possible protective effects of β2GPI and reduced β2GPI on diabetic nephropathy (DN) are not fully elucidated. The purpose of this study was to test a hypothesis that β2GPI and reduced β2GPI would improve DN in streptozotocin (STZ) induced diabetic mice and high-glucose (HG) exposed rat mesangial cell (RMC). Methods: The STZ-induced Balb/c mice and HG exposed RMCs were administrated with β2-GPI and reduced β2-GPI at different time and concentrations gradient respectively. The changes of glomerular structure and expression of collagen IV, TGF-β1, p38 MAPK and phospho-p38 MAPK in renal cortical and mesangial cells were observed by immunohistochemical techniques, quantitative real-time PCR and western blot with or without the treatment of β2-GPI and reduced β2-GPI. Results: β2GPI and reduced β2GPI improved early clinical and pathological changes of DN in STZ-diabetic mice. Treatment with β2GPI and reduced β2GPI in the STZ-diabetic mice and HG exposed RMCs resulted in decrease expression levels of TGF-β1 and collagen IV, with concomitant decrease in phospho-p38 MAPK expression. Conclusions: β2GPI and reduced β2GPI improved renal structural damage and kidney function. The renoprotective and antifibrosis effects of β2GPI and reduced β2GPI on DN were closely associated with suppressing the activation of the TGF-β1-p38 MAPK pathway. PMID:26045739

  12. Modulation of radiation injury response in retinal endothelial cells by quinic acid derivative KZ-41 involves p38 MAPK.

    PubMed

    Toutounchian, Jordan J; Steinle, Jena J; Makena, Patrudu S; Waters, Christopher M; Wilson, Matthew W; Haik, Barrett G; Miller, Duane D; Yates, Charles R

    2014-01-01

    Radiation-induced damage to the retina triggers leukostasis, retinal endothelial cell (REC) death, and subsequent hypoxia. Resultant ischemia leads to visual loss and compensatory retinal neovascularization (RNV). Using human RECs, we demonstrated that radiation induced leukocyte adhesion through mechanisms involving p38MAPK, p53, and ICAM-1 activation. Additional phenotypic changes included p38MAPK-dependent tyrosine phosphorylation of the focal adhesion scaffolding protein, paxillin (Tyr118). The quinic acid derivative KZ-41 lessened leukocyte adhesion and paxillin-dependent proliferation via inhibition of p38MAPK-p53-ICAM-1 signaling. Using the murine oxygen-induced retinopathy (OIR) model, we examined the effect of KZ-41 on pathologic RNV. Daily ocular application of a KZ-41-loaded nanoemulsion significantly reduced both the avascular and neovascular areas in harvested retinal flat mounts when compared to the contralateral eye receiving vehicle alone. Our data highlight the potential benefit of KZ-41 in reducing both the retinal ischemia and neovascularization provoked by genotoxic insults. Further research into how quinic acid derivatives target and mitigate inflammation is needed to fully appreciate their therapeutic potential for the treatment of inflammatory retinal vasculopathies. PMID:24956278

  13. Deficiency of Neuronal p38α MAPK Attenuates Amyloid Pathology in Alzheimer Disease Mouse and Cell Models through Facilitating Lysosomal Degradation of BACE1.

    PubMed

    Schnöder, Laura; Hao, Wenlin; Qin, Yiren; Liu, Shirong; Tomic, Inge; Liu, Xu; Fassbender, Klaus; Liu, Yang

    2016-01-29

    Amyloid β (Aβ) damages neurons and triggers microglial inflammatory activation in the Alzheimer disease (AD) brain. BACE1 is the primary enzyme in Aβ generation. Neuroinflammation potentially up-regulates BACE1 expression and increases Aβ production. In Alzheimer amyloid precursor protein-transgenic mice and SH-SY5Y cell models, we specifically knocked out or knocked down gene expression of mapk14, which encodes p38α MAPK, a kinase sensitive to inflammatory and oxidative stimuli. Using immunological and biochemical methods, we observed that reduction of p38α MAPK expression facilitated the lysosomal degradation of BACE1, decreased BACE1 protein and activity, and subsequently attenuated Aβ generation in the AD mouse brain. Inhibition of p38α MAPK also enhanced autophagy. Blocking autophagy by treating cells with 3-methyladenine or overexpressing dominant-negative ATG5 abolished the deficiency of the p38α MAPK-induced BACE1 protein reduction in cultured cells. Thus, our study demonstrates that p38α MAPK plays a critical role in the regulation of BACE1 degradation and Aβ generation in AD pathogenesis.

  14. AMPK Regulates Metabolic Actions of Glucocorticoids by Phosphorylating the Glucocorticoid Receptor through p38 MAPK

    PubMed Central

    Nader, Nancy; Ng, Sinnie Sin Man; Lambrou, George I.; Pervanidou, Panagiota; Wang, Yonghong; Chrousos, George P.; Kino, Tomoshige

    2010-01-01

    Glucocorticoids play central roles in the regulation of energy metabolism by shifting it toward catabolism, whereas AMP-activated protein kinase (AMPK) is the master regulator of energy homeostasis, sensing energy depletion and stimulating pathways of increasing fuel uptake and saving on peripheral supplies. We showed here that AMPK regulates glucocorticoid actions on carbohydrate metabolism by targeting the glucocorticoid receptor (GR) and modifying transcription of glucocorticoid-responsive genes in a tissue- and promoter-specific fashion. Activation of AMPK in rats reversed glucocorticoid-induced hepatic steatosis and suppressed glucocorticoid-mediated stimulation of glucose metabolism. Transcriptomic analysis in the liver suggested marked overlaps between the AMPK and glucocorticoid signaling pathways directed mostly from AMPK to glucocorticoid actions. AMPK accomplishes this by phosphorylating serine 211 of the human GR indirectly through phosphorylation and consequent activation of p38 MAPK and by altering attraction of transcriptional coregulators to DNA-bound GR. In human peripheral mononuclear cells, AMPK mRNA expression positively correlated with that of glucocorticoid-responsive glucocorticoid-inducible leucine zipper protein, which correlated also positively with the body mass index of subjects. These results indicate that the AMPK-mediated energy control system modulates glucocorticoid action at target tissues. Because increased action of glucocorticoids is associated with the development of metabolic disorders, activation of AMPK could be a promising target for developing pharmacological interventions to these pathologies. PMID:20660302

  15. Inhibition of respiratory syncytial virus replication and virus-induced p38 kinase activity by berberine.

    PubMed

    Shin, Han-Bo; Choi, Myung-Soo; Yi, Chae-Min; Lee, Jun; Kim, Nam-Jung; Inn, Kyung-Soo

    2015-07-01

    Respiratory syncytial virus (RSV) causes severe lower respiratory tract infection and poses a major public health threat worldwide. No effective vaccines or therapeutics are currently available; berberine, an isoquinoline alkaloid from various medicinal plants, has been shown to exert antiviral and several other biological effects. Recent studies have shown that p38 mitogen-activated protein kinase (MAPK) activity is implicated in infection by and replication of viruses such as RSV and the influenza virus. Because berberine has previously been implicated in modulating the activity of p38 MAPK, its effects on RSV infection and RSV-mediated p38 MAPK activation were examined. Replication of RSV in epithelial cells was significantly reduced by treatment with berberine. Berberine treatment caused decrease in viral protein and mRNA syntheses. Similar to previously reported findings, RSV infection caused phosphorylation of p38 MAPK at a very early time point of infection, and phosphorylation was dramatically reduced by berberine treatment. In addition, production of interleukin-6 mRNA upon RSV infection was significantly suppressed by treatment with berberine, suggesting the anti-inflammatory role of berberine during RSV infection. Taken together, we showed that berberine, a natural compound already proven to be safe for human consumption, suppresses the replication of RSV. In addition, the current study suggests that inhibition of RSV-mediated early p38 MAPK activation, which has been implicated as an early step in viral infection, as a potential molecular mechanism.

  16. Osteoprotegerin induces podosome disassembly in osteoclasts through calcium, ERK, and p38 MAPK signaling pathways.

    PubMed

    Zhao, Hongyan; Liu, Xuezhong; Zou, Hui; Dai, Nannan; Yao, Lulian; Gao, Qian; Liu, Wei; Gu, Jianhong; Yuan, Yan; Bian, Jianchun; Liu, Zongping

    2015-02-01

    Osteoclasts are critical for bone resorption and use podosomes to attach to bone matrix. Osteoprotegerin (OPG) is a negative regulator of osteoclast function that can affect the formation and function of podosomes. However, the signaling pathways that link OPG to podosome function have not been well characterized. Therefore, this study examined the roles of intracellular calcium and MAPKs in OPG-induced podosome disassembly in osteoclasts. We assessed the effects of the intracellular calcium chelator Bapta-AM, ERK inhibitor U0126, and p38 inhibitor SB202190 on OPG-treated osteoclast differentiation, adhesion structures, intracellular free Ca(2+) concentration and the phosphorylation state of podosome associated proteins (Pyk2 and Src). Mouse monocytic RAW 264.7 cells were differentiated to osteoclasts using RANKL (30ng/mL) and M-CSF (25ng/mL). The cells were pretreated with Bapta-AM (5μM), U0126 (5μM), or SB202190 (10μM) for 30min, followed by 40ng/mL OPG for 3h. Osteoclastogenesis, adhesion structure, viability and morphology, intracellular free Ca(2+) concentration and the phosphorylation state of Pyk2 and Src were measured by TRAP staining, scanning electron microscopy, real-time cell analyzer, flow cytometry and western blotting, respectively. OPG significantly inhibited osteoclastogenesis, the formation of adhesion structures, and reduced the amount of phosphorylated Pyk2 and Src-pY527, but increased phosphorylation of Src-pY416. Bapta-AM, U0126, and SB202190 partially restored osteoclast differentiation and adhesion structures. Both Bapta-AM and U0126, but not SB202190, restored the levels of intracellular free Ca(2+) concentration, phosphorylated Pyk2 and Src-pY527. All three inhibitors blocked OPG-induced phosphorylation at Src-pY416. These results suggest OPG disrupts the attachment structures of osteoclasts and activates Src as an adaptor protein that competes for the reduced amount of phosphorylated Pyk2 through calcium- and ERK-dependent signaling

  17. p38 MAPK-induced MDM2 degradation confers paclitaxel resistance through p53-mediated regulation of EGFR in human lung cancer cells

    PubMed Central

    Park, Shin-Hyung; Seong, Myeong-A; Lee, Ho-Young

    2016-01-01

    Paclitaxel (PTX) is a chemotherapeutic agent that is used to treat a variety of cancers, including non-small cell lung cancer (NSCLC). However, the emergence of drug resistance limits the utility of PTX. This study determined the signaling pathway that contributes to PTX resistance. We first established PTX resistant cell lines (H460/R and 226B/R) using a dose-escalating maintenance of PTX. We found that p38 MAPK and epidermal growth factor receptor (EGFR) were constitutively activated in these cell lines. The inhibition of p38 MAPK activity by SB203580 treatment or the transfection of dominant-negative p38 MAPK sensitized both cell lines to PTX treatment. Erlotinib, an EGFR inhibitor, also increased PTX-induced apoptosis in PTX resistant cells, which suggests a role for p38 MAPK and EGFR in the development of PTX resistance. We demonstrated that p38 MAPK enhanced EGFR expression via the induction of the rapid degradation of mouse double-minute 2 homolog (MDM2) and the consequent stabilization of p53, a transcription factor of EGFR. These results suggest for the first time that the p38 MAPK/p53/EGFR axis is crucial for the facilitation of PTX resistance in NSCLCs. We also propose a mechanism for the role of the tumor-suppressor p53 in drug resistance. These results provide a foundation for the future development of potential therapeutic strategies to regulate the p38 MAPK/p53/EGFR pathway for the treatment of lung cancer patients with PTX resistance. PMID:26799187

  18. Obacunone exhibits anti-proliferative and anti-aromatase activity in vitro by inhibiting the p38 MAPK signaling pathway in MCF-7 human breast adenocarcinoma cells.

    PubMed

    Kim, Jinhee; Jayaprakasha, G K; Patil, Bhimanagouda S

    2014-10-01

    Overexpression of the aromatase enzyme CYP19 has been implicated in the onset of estrogen-dependent breast carcinogenesis. Obacunone, a natural compound present in citrus fruits, has been demonstrated for various biological activities including anti-cancer and anti-inflammatory properties. In the present study, we have isolated obacunone and obacunone glucoside (OG) from lemon seeds, then fractionated these compounds using chromatographic techniques and characterized them by HPLC, LC-MS, and 2D NMR spectral analysis. To investigate the mechanism of anti-cancer and anti-aromatase activities of limonoids, their cytotoxic effect was tested on human breast cancer (MCF-7) and non-malignant (MCF-12F) breast cells. MTT assays confirmed that obacunone was strongly inhibited MCF-7 cell proliferation without affecting non-malignant breast cells. Treatment with obacunone increased apoptosis by up-regulating expression of the pro-apoptotic protein Bax and down-regulating the anti-apoptotic protein Bcl2, as well as inducing G1 cell cycle arrest. In addition, obacunone significantly inhibited aromatase activity in an in vitro enzyme assay. Exposure of MCF-7 breast cancer cells to obacunone down-regulated expression of inflammatory molecules including nuclear factor-kappa B (NF-κB) and cyclooxygenase-2 (COX-2). Furthermore, we found that obacunone inhibited COX-2 and NF-κB by activation of the p38 mitogen-activated protein kinase (MAPK). Finally, the uptake level of obacunone into MCF-7 cells was measured by HPLC and its structure was confirmed by LC-HR-MS. This study demonstrated that obacunone may have the potential to prevent estrogen-responsive breast cancer through inhibition of the aromatase enzyme and inflammatory pathways, as well as activation of apoptosis. PMID:24927687

  19. Resokaempferol-mediated anti-inflammatory effects on activated macrophages via the inhibition of JAK2/STAT3, NF-κB and JNK/p38 MAPK signaling pathways.

    PubMed

    Yu, Qian; Zeng, KeWu; Ma, XiaoLi; Song, FangJiao; Jiang, Yong; Tu, PengFei; Wang, XueMei

    2016-09-01

    The excessive or prolonged production of inflammatory mediators can result in numerous chronic diseases, such as rheumatoid arthritis, atherosclerosis, diabetes, and cancer. Therefore, for many inflammatory-related diseases, pharmaceutical intervention is required to restrain the excessive release of such inflammatory mediators. Novel therapeutics and mechanistic insight are sought for the management of chronic inflammatory diseases. Resokaempferol (RES) is a type of flavonoid recently reported to demonstrate anti-cancer properties. However, the anti-inflammatory capacity of RES has not been studied to date. Therefore, this study investigated whether RES is capable of suppressing the inflammatory response to lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and the mechanism by which this is achieved. We found that RES attenuated the LPS-induced production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), monocyte chemotactic protein 1 (MCP-1) and IL-6. RES also inhibited the nuclear translocation of signal transducer and activator of transcription (STAT) 3 and reduced the LPS-mediated phosphorylation of Janus kinase (JAK) 2 and STAT3 at the sites of Ser727 and Tyr705. RES also inhibited the activation of NF-κB and JNK/p38 MAPK signaling pathways in LPS-induced RAW264.7 cells. Additionally, RES inhibited the activation of the JAK2/STAT3 pathway in exogenous IL-6-activated RAW264.7 macrophages. We conclude that RES inhibits the inflammatory response in activated macrophages by blocking the activation of the JAK2/STAT3 pathway by both LPS and IL-6 signaling. PMID:27261558

  20. [Serum amyloid A promotes the inflammatory response via p38-MAPK/SR-BI pathway in THP-1 macrophages].

    PubMed

    Zhu, Ming-Yan; Wang, Yan; Wang, Yu; Peng, Feng-Ling; Ou, Han-Xiao; Zheng, Xiang; Shi, Jin-Feng; Zeng, Gao-Feng; Mo, Zhong-Cheng

    2016-06-25

    To investigate the effect and mechanism of serum amyloid A (SAA) on the expression of scavenger receptor class B type I (SR-BI) and inflammatory response in THP-1 macrophages, the human THP-1 cells were treated with SAA and p38-MAPK agonist (anisomycin) or p38-MAPK inhibitor (SB203580). Then, the expressions of SR-BI, phosphorylated p38-MAPK and inflammatory factors (MCP-1, TNF-α, IL-1β) were examined by real-time quantitative PCR, Western blotting and ELISA, respectively. The results showed that, compared with control group, SAA increased the levels of inflammatory factors (MCP-1, TNF-α, IL-1β), down-regulated the expressions of SR-BI, and up-regulated the expression of phosphorylated p38-MAPK protein in a concentration- and time-dependent manner in THP-1 cells (P < 0.05). After treatment with SAA and p38-MAPK agonist (anisomycin) in THP-1 cells, the expression of SR-BI was down-regulated, and the levels of inflammatory factors and phosphorylated p38-MAPK protein expression were increased, compared with the group only treated by SAA (P < 0.05). In contrast, the SR-BI expression was up-regulated, whereas inflammatory factors and phosphorylated p38-MAPK protein expressions were decreased after the cells were treated with SAA and p38-MAPK inhibitor (SB203580) (P < 0.05). The results suggest that SAA-promoted inflammatory response in THP-1 macrophages may be through the phosphorylation of p38-MAPK and inhibition of SR-BI expression. PMID:27350202

  1. Inhibition of cyclophilin A suppresses H2O2-enhanced replication of HCMV through the p38 MAPK signaling pathway.

    PubMed

    Xiao, Jun; Song, Xin; Deng, Jiang; Lv, Liping; Ma, Ping; Gao, Bo; Zhou, Xipeng; Zhang, Yanyu; Xu, Jinbo

    2016-09-01

    Human cytomegalovirus (HCMV) infection can be accelerated by intracellular and extracellular hydrogen peroxide (H2O2) stimulation, mediated by the activation of the p38 mitogen-activated protein kinase (MAPK) pathway. However, it remains unknown whether host gene expression is involved in H2O2-upregulated HCMV replication. Here, we show that the expression of the host gene, cyclophilin A (CyPA), could be facilitated by treatment with H2O2 in a dose-dependent manner. Experiments with CyPA-specific siRNA, or with cyclosporine A, an inhibitor of CyPA, confirmed that H2O2-mediated upregulation of HCMV replication is specifically mediated by upregulation of CyPA expression. Furthermore, depletion or inhibition of CyPA reduced H2O2-induced p38 activation, consistent with that of H2O2-upregulated HCMV lytic replication. These results show that H2O2 is capable of activating ROS-CyPA-p38 MAPK interactions to enhance HCMV replication. PMID:27642560

  2. Inhibition of cyclophilin A suppresses H2O2-enhanced replication of HCMV through the p38 MAPK signaling pathway.

    PubMed

    Xiao, Jun; Song, Xin; Deng, Jiang; Lv, Liping; Ma, Ping; Gao, Bo; Zhou, Xipeng; Zhang, Yanyu; Xu, Jinbo

    2016-09-01

    Human cytomegalovirus (HCMV) infection can be accelerated by intracellular and extracellular hydrogen peroxide (H2O2) stimulation, mediated by the activation of the p38 mitogen-activated protein kinase (MAPK) pathway. However, it remains unknown whether host gene expression is involved in H2O2-upregulated HCMV replication. Here, we show that the expression of the host gene, cyclophilin A (CyPA), could be facilitated by treatment with H2O2 in a dose-dependent manner. Experiments with CyPA-specific siRNA, or with cyclosporine A, an inhibitor of CyPA, confirmed that H2O2-mediated upregulation of HCMV replication is specifically mediated by upregulation of CyPA expression. Furthermore, depletion or inhibition of CyPA reduced H2O2-induced p38 activation, consistent with that of H2O2-upregulated HCMV lytic replication. These results show that H2O2 is capable of activating ROS-CyPA-p38 MAPK interactions to enhance HCMV replication.

  3. Regulation of Muscle Stem Cell Functions: A Focus on the p38 MAPK Signaling Pathway

    PubMed Central

    Segalés, Jessica; Perdiguero, Eusebio; Muñoz-Cánoves, Pura

    2016-01-01

    Formation of skeletal muscle fibers (myogenesis) during development and after tissue injury in the adult constitutes an excellent paradigm to investigate the mechanisms whereby environmental cues control gene expression programs in muscle stem cells (satellite cells) by acting on transcriptional and epigenetic effectors. Here we will review the molecular mechanisms implicated in the transition of satellite cells throughout the distinct myogenic stages (i.e., activation from quiescence, proliferation, differentiation, and self-renewal). We will also discuss recent findings on the causes underlying satellite cell functional decline with aging. In particular, our review will focus on the epigenetic changes underlying fate decisions and on how the p38 MAPK signaling pathway integrates the environmental signals at the chromatin to build up satellite cell adaptive responses during the process of muscle regeneration, and how these responses are altered in aging. A better comprehension of the signaling pathways connecting external and intrinsic factors will illuminate the path for improving muscle regeneration in the aged. PMID:27626031

  4. Regulation of Muscle Stem Cell Functions: A Focus on the p38 MAPK Signaling Pathway.

    PubMed

    Segalés, Jessica; Perdiguero, Eusebio; Muñoz-Cánoves, Pura

    2016-01-01

    Formation of skeletal muscle fibers (myogenesis) during development and after tissue injury in the adult constitutes an excellent paradigm to investigate the mechanisms whereby environmental cues control gene expression programs in muscle stem cells (satellite cells) by acting on transcriptional and epigenetic effectors. Here we will review the molecular mechanisms implicated in the transition of satellite cells throughout the distinct myogenic stages (i.e., activation from quiescence, proliferation, differentiation, and self-renewal). We will also discuss recent findings on the causes underlying satellite cell functional decline with aging. In particular, our review will focus on the epigenetic changes underlying fate decisions and on how the p38 MAPK signaling pathway integrates the environmental signals at the chromatin to build up satellite cell adaptive responses during the process of muscle regeneration, and how these responses are altered in aging. A better comprehension of the signaling pathways connecting external and intrinsic factors will illuminate the path for improving muscle regeneration in the aged. PMID:27626031

  5. p38 MAPK Inhibitor Insufficiently Attenuates HSC Senescence Administered Long-Term after 6 Gy Total Body Irradiation in Mice

    PubMed Central

    Lu, Lu; Wang, Yue-Ying; Zhang, Jun-Ling; Li, De-Guan; Meng, Ai-Min

    2016-01-01

    Senescent hematopoietic stem cells (HSCs) accumulate with age and exposure to stress, such as total-body irradiation (TBI), which may cause long-term myelosuppression in the clinic. However, the methods available for long-term myelosuppression remain limited. Previous studies have demonstrated that sustained p38 mitogen-activated protein kinases (p38 MAPK) activation in HSCs following exposure to TBI in mice and the administration of its inhibitor twenty-four hours after TBI may partially prevent long-term myelosuppression. However, long-term myelosuppression is latent and identified long after the administration of radiation. In this study, we investigated the effects of SB203580 (a small molecule inhibitor of p38 MAPK) on long-term myelosuppression induced by TBI. Mice with hematopoietic injury were injected intraperitoneally with SB203580 every other day five times beginning 70 days after 6 Gy of 137Cs γ ray TBI. Our results at 80 days demonstrated that SB203580 did not significantly improve the TBI-induced long-term reduction of peripheral blood cell and bone marrow nucleated cell (BMNC) counts, or defects in hematopoietic progenitor cells (HPCs) and HSC clonogenic function. SB203580 reduced reactive oxygen species (ROS) production and p-p38 expression; however, SB203580 had no effect on p16 expression in the HSCs of mice. In conclusion, these findings suggest that treatment with SB203580 70 days after TBI in mice inhibits the ROS-p38 oxidative stress pathway; however, it has no therapeutic effect on long-term myelosuppression induced by TBI. PMID:27338355

  6. Clonidine, an alpha-2 adrenoceptor agonist relieves mechanical allodynia in oxaliplatin-induced neuropathic mice; potentiation by spinal p38 MAPK inhibition without motor dysfunction and hypotension.

    PubMed

    Yeo, Ji-Hee; Yoon, Seo-Yeon; Kim, Sol-Ji; Oh, Seog-Bae; Lee, Jang-Hern; Beitz, Alvin J; Roh, Dae-Hyun

    2016-05-15

    Cancer chemotherapy with platinum-based antineoplastic agents including oxaliplatin frequently results in a debilitating and painful peripheral neuropathy. We evaluated the antinociceptive effects of the alpha-2 adrenoceptor agonist, clonidine on oxaliplatin-induced neuropathic pain. Specifically, we determined if (i) the intraperitoneal (i.p.) injection of clonidine reduces mechanical allodynia in mice with an oxaliplatin-induced neuropathy and (ii) concurrent inhibition of p38 mitogen-activated protein kinase (MAPK) activity by the p38 MAPK inhibitor SB203580 enhances clonidine's antiallodynic effect. Clonidine (0.01-0.1 mg kg(-1), i.p.), with or without SB203580(1-10 nmol, intrathecal) was administered two weeks after oxaliplatin injection(10 mg kg(-1), i.p.) to mice. Mechanical withdrawal threshold, motor coordination and blood pressure were measured. Postmortem expression of p38 MAPK and ERK as well as their phosphorylated forms(p-p38 and p-ERK) were quantified 30 min or 4 hr after drug injection in the spinal cord dorsal horn of treated and control mice. Clonidine dose-dependently reduced oxaliplatin-induced mechanical allodynia and spinal p-p38 MAPK expression, but not p-ERK. At 0.1 mg kg(-1), clonidine also impaired motor coordination and decreased blood pressure. A 10 nmol dose of SB203580 alone significantly reduced mechanical allodynia and p-p38 MAPK expression, while a subeffective dose(3 nmol) potentiated the antiallodynic effect of 0.03 mg kg(-1) clonidine and reduced the increased p-p38 MAPK. Coadministration of SB203580 and 0.03 mg kg(-1) clonidine decreased allodynia similar to that of 0.10 mg kg(-1) clonidine, but without significant motor or vascular effects. These findings demonstrate that clonidine treatment reduces oxaliplatin-induced mechanical allodynia. The concurrent administration of SB203580 reduces the dosage requirements for clonidine, thereby alleviating allodynia without producing undesirable motor or cardiovascular effects.

  7. Atg7 Knockdown Augments Concanavalin A-Induced Acute Hepatitis through an ROS-Mediated p38/MAPK Pathway.

    PubMed

    Zhuang, Yan; Li, Yi; Li, Xuefeng; Xie, Qing; Wu, Min

    2016-01-01

    Concanavalin A (ConA), a T-cell mitogen that induces acute autoimmune hepatitis, is widely used to model pathophysiological processes of human acute autoimmune liver disease. Although autophagy has been extensively studied in the past decade, little is known about its molecular mechanism underlying the regulation of ConA-induced acute hepatitis. In this study, we used a Cre-conditional atg7 KO mouse to investigate the effects of Atg7-associated autophagy on ConA-induced murine hepatitis. Our results demonstrated that atg7 deficiency in mice enhanced macrophage activation and increased pro-inflammatory cytokines upon ConA stimulation. Atg7 silencing resulted in accumulation of dysfunctional mitochondria, disruption of reactive oxygen species (ROS) degradation, and increase in pro-inflammatory cytokines in Raw264.7 cells. p38/MAPK and NF-κB levels were increased upon ConA induction due to Atg7 deficiency. Blocking ROS production inhibited ConA-induced p38/IκB phosphorylation and subsequent intracellular inflammatory responses. Hence, this study demonstrated that atg7 knockout in mice or Atg7 knockdown in cell culture augmented ConA-induced acute hepatitis and related cellular malfunction, indicating protective effects of Atg7 on regulating mitochondrial ROS via a p38/MAPK-mediated pathway. Collectively, our findings reveal that autophagy may attenuate macrophage-mediated inflammatory response to ConA and may be the potential therapeutic targets for acute liver injury. PMID:26939081

  8. Magnolol protects neurons against ischemia injury via the downregulation of p38/MAPK, CHOP and nitrotyrosine

    SciTech Connect

    Chen, Jiann-Hwa; Kuo, Hsing-Chun; Lee, Kam-Fai; Tsai, Tung-Hu

    2014-09-15

    Magnolol is isolated from the herb Magnolia officinalis, which has been demonstrated to exert pharmacological effects. Our aim was to investigate whether magnolol is able to act as an anti-inflammatory agent that brings about neuroprotection using a global ischemic stroke model and to determine the mechanisms involved. Rats were treated with and without magnolol after ischemia reperfusion brain injury by occlusion of the two common carotid arteries. The inflammatory cytokine production in serum and the volume of infarction in the brain were measured. The proteins present in the brains obtained from the stroke animal model (SAM) and control animal groups with and without magnolol treatment were compared. Magnolol reduces the total infarcted volume by 15% and 30% at dosages of 10 and 30 mg/kg, respectively, compared to the untreated SAM group. The levels of acute inflammatory cytokines, including interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 were attenuated by magnolol. Magnolol was also able to suppress the production of nitrotyrosine, 4-hydroxy-2-nonenal (4-HNE), inducible NO synthase (iNOS), various phosphorylated p38 mitogen-activated protein kinases and various C/EBP homologues. Furthermore, this modulation of ischemia injury factors in the SAM model group treated with magnolol seems to result from a suppression of reactive oxygen species production and the upregulation of p-Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). These findings confirm the anti-oxidative properties of magnolol, including the inhibition of ischemic injury to neurons; this protective effect seems to involve changes in the in vivo activity of Akt, GSK3β and NF-κB. - Graphical abstract: Schematic presentation of the signaling pathways involved in magnolol inhibited transient global ischemia brain apoptosis and inflammation in rats. The effect of magnolol on the scavenger of ROS, which inhibits p38 MAPK and CHOP protein inactivation

  9. SB203580 Modulates p38 MAPK Signaling and Dengue Virus-Induced Liver Injury by Reducing MAPKAPK2, HSP27, and ATF2 Phosphorylation

    PubMed Central

    Sreekanth, Gopinathan Pillai; Chuncharunee, Aporn; Sirimontaporn, Aunchalee; Panaampon, Jutatip; Noisakran, Sansanee; Yenchitsomanus, Pa-thai; Limjindaporn, Thawornchai

    2016-01-01

    Dengue virus (DENV) infection causes organ injuries, and the liver is one of the most important sites of DENV infection, where viral replication generates a high viral load. The molecular mechanism of DENV-induced liver injury is still under investigation. The mitogen activated protein kinases (MAPKs), including p38 MAPK, have roles in the hepatic cell apoptosis induced by DENV. However, the in vivo role of p38 MAPK in DENV-induced liver injury is not fully understood. In this study, we investigated the role of SB203580, a p38 MAPK inhibitor, in a mouse model of DENV infection. Both the hematological parameters, leucopenia and thrombocytopenia, were improved by SB203580 treatment and liver transaminases and histopathology were also improved. We used a real-time PCR microarray to profile the expression of apoptosis-related genes. Tumor necrosis factor α, caspase 9, caspase 8, and caspase 3 proteins were significantly lower in the SB203580-treated DENV-infected mice than that in the infected control mice. Increased expressions of cytokines including TNF-α, IL-6 and IL-10, and chemokines including RANTES and IP-10 in DENV infection were reduced by SB203580 treatment. DENV infection induced the phosphorylation of p38MAPK, and its downstream signals including MAPKAPK2, HSP27 and ATF-2. SB203580 treatment did not decrease the phosphorylation of p38 MAPK, but it significantly reduced the phosphorylation of MAPKAPK2, HSP27, and ATF2. Therefore, SB203580 modulates the downstream signals to p38 MAPK and reduces DENV-induced liver injury. PMID:26901653

  10. Adiponectin Impairs Chicken Preadipocytes Differentiation through p38 MAPK/ATF-2 and TOR/p70 S6 Kinase Pathways

    PubMed Central

    Yan, Jun; Gan, Lu; Chen, Di; Sun, Chao

    2013-01-01

    Adiponectin is a protein hormone secreted exclusively by adipocytes that plays an important role in the modulation of glucose and lipid metabolism. In the present study, we investigated the ability of adiponectin to stimulate chicken preadipocyte differentiation and its effect on cellular signaling pathways associated with adipocyte differentiation. Data showed that over-expression of adiponectin inhibited adipocyte differentiation and the expression of adipogenic marker gene, while activated the expression of lipolytic marker gene. Meanwhile, adiponectin led to activation of p38 mitogen-activated protein kinase (p38 MAPK)/activating transcription factor 2 (ATF-2) signaling pathway and down-regulation of target of rapamycin (TOR)/p70 S6 Kinase signaling pathway. Furthermore, the activation of p38 MAPK/ATF-2 signaling pathway was blocked by the p38 MAPK inhibitor SB253580, whereas adiponectin had a synergistic effect on the suppression of TOR/p70 S6 Kinase signaling pathway with the TOR inhibitor rapamycin. In conclusion, the results demonstrate the ability of adiponectin to inhibit chicken preadipocyte differentiation, which depends on the p38 MAPK/ATF-2 and TOR/p70 S6 Kinase pathways. PMID:24194895

  11. p38 Mitogen-Activated Protein Kinase Pathway Regulates Genes during Proliferation and Differentiation in Oligodendrocytes

    PubMed Central

    Haines, Jeffery D.; Fulton, Debra L.; Richard, Stephane; Almazan, Guillermina

    2015-01-01

    We have previously shown that p38 mitogen-activated protein kinase (p38 MAPK) is important for oligodendrocyte (OLG) differentiation and myelination. However, the precise cellular mechanisms by which p38 regulates OLG differentiation remain largely unknown. To determine whether p38 functions in part through transcriptional events in regulating OLG identity, we performed microarray analysis on differentiating oligodendrocyte progenitors (OLPs) treated with a p38 inhibitor. Consistent with a role in OLG differentiation, pharmacological inhibition of p38 down-regulated the transcription of genes that are involved in myelin biogenesis, transcriptional control and cell cycle. Proliferation assays showed that OLPs treated with the p38 inhibitor retained a proliferative capacity which could be induced upon application of mitogens demonstrating that after two days of p38-inhibition OLGs remained poised to continue mitosis. Together, our results suggest that the p38 pathway regulates gene transcription which can coordinate OLG differentiation. Our microarray dataset will provide a useful resource for future studies investigating the molecular mechanisms by which p38 regulates oligodendrocyte differentiation and myelination. PMID:26714323

  12. The essential role of p38 MAPK in mediating the interplay of oxLDL and IL-10 in regulating endothelial cell apoptosis.

    PubMed

    Yin, Yanlin; Liu, Weiwei; Ji, Guo; Dai, Yalei

    2013-01-01

    Interleukin-10 (IL-10) may have therapeutic potential in various inflammatory diseases, including atherosclerosis, as it can inhibit oxLDL-induced foam cell formation and apoptosis in macrophages. This study investigated the effect of IL-10 on mitogen-activated protein kinase (MAPK) activation, and apoptosis induced by oxidized low-density lipoprotein (oxLDL) in cultured human umbilical vein endothelial cells (HUVEC). The results demonstrated that IL-10 significantly blocked the phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) and apoptosis induced by oxLDL. The inhibitory effect of IL-10 on oxLDL-induced apoptosis was partially dependent on reduced p38, but not JNK, phosphorylation. This study also discovered a linkage between IL-10 and p38 MAPK signaling in oxLDL-induced endothelial cell apoptosis. Interestingly, this study found that lectin-like oxidized LDL receptor-1 (LOX-1) was the only scavenger receptor, on the surface of HUVEC, that was upregulated by oxLDL and the increase in LOX-1 was not suppressed by IL-10. This study confirmed that IL-10 significantly upregulated the expression of suppressor of cytokine signaling-3 (SOCS3), whereas SOCS3 knockdown by siRNA effectively blocked the inhibitory effect of IL-10 on p38 MAPK-dependent apoptosis induced by oxLDL. These results showed for the first time, that IL-10 modulated oxLDL-induced apoptosis by upregulating SOCS3, which then interrupted p38 MAPK activation in endothelial cells. These findings support the essential role of p38 MAPK in the interplay of oxLDL and IL-10 in endothelial apoptosis. PMID:23498167

  13. p38 mitogen-activated protein kinase plays a key role in regulating MAPKAPK2 expression

    SciTech Connect

    Sudo, Tatsuhiko . E-mail: sudo@riken.jp; Kawai, Kayoko; Matsuzaki, Hiroshi; Osada, Hiroyuki

    2005-11-18

    One of three major families of the mitogen-activated kinases (MAPK), p38 as well as JNK, has been shown to transduce extracellular stress stimuli into cellular responses by phospho-relay cascades. Among p38 families, p38{alpha} is a widely characterized isoform and the biological phenomena are explained by its kinase activity regulating functions of its downstream substrates. However, its specific contributions to each phenomenon are yet not fully elucidated. For better understanding of the role of MAPKs, especially p38{alpha}, we utilized newly established mouse fibroblast cell lines originated from a p38{alpha} null mouse, namely, a parental cell line without p38{alpha} gene locus, knockout of p38{alpha} (KOP), Zeosin-resistant (ZKOP), revertant of p38{alpha} (RKOP), and Exip revertant (EKOP). EKOP is smaller in size but grows faster than the others. Although comparable amounts of ERK and JNK are expressed in each cell line, ERK is highly phosphorylated in EKOP even in normal culture conditions. Serum stimulation after serum starvation led to ERK phosphorylation in RKOP and ZKOP, but not in EKOP as much. On the contrary, relative phosphorylation level of JNK to total JNK in response to UV was low in RKOP. And its phosphorylation as well as total JNK is slightly lower in EKOP. RKOP is less sensitive to UV irradiation as judged by the survival rate. Stress response upon UV or sorbitol stimuli, leading to mitogen activate protein kinase activated kinase 2 (MAPKAPK2) phosphorylation, was only observed in RKOP. Further experiments reveal that MAPKAPK2 expression is largely suppressed in ZKOP and EKOP. Its expression was recovered by re-introduction of p38{alpha}. The loss of MAPKAPK2 expression accompanied by the defect of p38{alpha} is confirmed in an embryonic extract prepared from p38{alpha} null mice. These data demonstrate that p38 signal pathway is regulated not only by phosphorylation but also by modulation of the expression of its component. Together, we have

  14. [Down-regulation of p38 MAPK and collagen by 1, 25-(OH)2-VD3 in rat models of diabetic nephropathy].

    PubMed

    Xie, Xianhui; Li, Zhengsheng; Pi, Mingjing; Wu, Jing; Zeng, Wen; Zuo, Li; Zha, Yan

    2016-07-01

    Objective To investigate the effect of 1, 25-(OH)2-VD3 on collagen type III (Col3), collagen type IV (Col4) and p38 mitogen-activated protein kinase (p38 MAPK) in rat models of type 2 diabetic nephropathy, and explore the relationships of p38MAPK with Col3 and Col4. Methods Rat models of type 2 diabetic nephropathy were induced by streptozocin (STZ, 30 mg/kg) combined with high-glucose-and-fat diet. Sixty rats were randomly divided into control group, model group, 1, 25-(OH)2-VD3 treatment group [given 1, 25-(OH)2-VD3 6 ng/(100 g.d) after modeling] and insulin group (given 2-3 U insulin after modeling). After 8 weeks' intervention, serum creatinine (Scr), blood urea nitrogen (BUN) and 24-hour proteinuria were detected in all groups. Periodic acid-Schiff (PAS) staining was used to observe the kidney pathological changes, and immunohistochemical staining and Western blotting were performed to determine p38 MAPK Col3 and Col4 expressions in rat renal interstitium. Spearman method was applied to the correlation analysis. Results Compared with the model group, blood glucose, Scr, BUN, 24-hour proteinuria and impaired renal interstitial area were all reduced in the 1, 25-(OH)2-VD3 treatment group and the insulin group. Compared with the control group, the expressions of Col3, Col4 and p38 MAPK were higher in the model group, and lower in the 1, 25-(OH)2-VD3 treatment group and the insulin group. Correlation analysis showed that 24-hour proteinuria was positively related with p38 MAPK, Col3, Col4 and immunohistochemical results; p38MAPK was positively correlated with Col3 and Col4 expressions. Conclusion Col3, Col4 and p38MAPK are up-regulated in rat models of type 2 diabetic nephropathy. The 1, 25-(OH)2-VD3 might attenuates the progression of renal interstitial fibrosis via down-regulating p38 MAPK, Col3 and Col4. PMID:27363275

  15. Role of PI3K, MAPK/ERK1/2, and p38 in implementation of the proliferative and differentiation potential of erythroid progenitors after blood loss.

    PubMed

    Dygai, A M; Zhdanov, V V; Miroshnichenko, L A; Udut, E V; Zyuz'kov, G N; Simanina, E V; Sherstoboev, E Yu; Chaikovskii, A V; Stavrova, L A; Burmina, Ya V; Khrichkova, T Yu; Reichart, D V; Goldberg, V E

    2015-02-01

    The involvement of PI3K, ERK and p38-dependent signaling system in the regulation of functional activity of erythroid precursors after blood loss (30% of circulating volume) was studied. We demonstrated the important role of PI3K and p38 in the suppression of differentiation of erythroid precursors the contribution of p38 to stimulation of mitotic activity of erythroid CFU, which maintains the growth potential of the precursors at the optimal physiological level. The classical MAPK/ERK-kinase pathway does not determine the proliferative and differentiation status of erythroid CFU. PMID:25711660

  16. p38 Mitogen-Activated Protein Kinase in beryllium-induced dendritic cell activation.

    PubMed

    Li, L; Huang, Z; Gillespie, M; Mroz, P M; Maier, L A

    2014-12-01

    Dendritic cells (DC) play a role in the regulation of immune responses to haptens, which in turn impact DC maturation. Whether beryllium (Be) is able to induce DC maturation and if this occurs via the MAPK pathway is not known. Primary monocyte-derived DCs (moDCs) models were generated from Be non-exposed healthy volunteers as a non-sensitized cell model, while PBMCs from BeS (Be sensitized) and CBD (chronic beryllium disease) were used as disease models. The response of these cells to Be was evaluated. The expression of CD40 was increased significantly (p<0.05) on HLA-DP Glu69+ moDCs after 100 μM BeSO₄-stimulation. BeSO₄ induced p38MAPK phosphorylation, while IκB-α was degraded in Be-stimulated moDCs. The p38 MAPK inhibitor SB203580 blocked Be-induced NF-κB activation in moDCs, suggesting that p38MAPK and NF-κB are dependently activated by BeSO₄. Furthermore, in BeS and CBD subjects, SB203580 downregulated Be-stimulated proliferation in a dose-dependent manner, and decreased Be-stimulated TNF-α and IFNγ cytokine production. Taken together, this study suggests that Be-induces non-sensitized Glu69+ DCs maturation, and that p38MAPK signaling is important in the Be-stimulated DCs activation as well as subsequent T cell proliferation and cytokine production in BeS and CBD. In total, the MAPK pathway may serve as a potential therapeutic target for human granulomatous lung diseases.

  17. p38 Mitogen-Activated Protein Kinase in beryllium-induced dendritic cell activation

    PubMed Central

    Li, L.; Huang, Z.; Gillespie, M.; Mroz, P.M.; Maier, L.A.

    2014-01-01

    Dendritic cells (DC) play a role in the regulation of immune responses to haptens, which in turn impact DC maturation. Whether beryllium (Be) is able to induce DC maturation and if this occurs via the MAPK pathway is not known. Primary monocyte-derived DCs (moDCs) models were generated from Be non-exposed healthy volunteers as a non-sensitized cell model, while PBMCs from BeS (Be sensitized) and CBD (chronic beryllium disease) were used as disease models. The response of these cells to Be was evaluated. The expression of CD40 was increased significantly (p<0.05) on HLA-DP Glu69+ moDCs after 100 μM BeSO4-stimulation. BeSO4 induced p38MAPK phosphorylation, while IκB-α was degraded in Be-stimulated moDCs. The p38 MAPK inhibitor SB203580 blocked Be-induced NF-κB activation in moDCs, suggesting that p38MAPK and NF-κB are dependently activated by BeSO4. Furthermore, in BeS and CBD subjects, SB203580 downregulated Be-stimulated proliferation in a dose-dependent manner, and decreased Be-stimulated TNF-α and IFNγ cytokine production. Taken together, this study suggests that Be-induces non-sensitized Glu69+ DCs maturation, and that p38MAPK signaling is important in the Be-stimulated DCs activation as well as subsequent T cell proliferation and cytokine production in BeS and CBD. In total, the MAPK pathway may serve as a potential therapeutic target for human granulomatous lung diseases. PMID:25454621

  18. Stress Induces p38 MAPK-mediated Phosphorylation and Inhibition of Drosha-dependent Cell Survival

    PubMed Central

    Yang, Qian; Li, Wenming; She, Hua; Dou, Juan; Duong, Duc M; Du, Yuhong; Yang, Shao-Hua; Seyfried, Nicholas T.; Fu, Haian; Gao, Guodong; Mao, Zixu

    2015-01-01

    SUMMARY MicroRNAs (miRNAs) regulate the translational potential of their mRNA targets and control many cellular processes. The key step in canonical miRNA biogenesis is the cleavage of the primary transcripts by the nuclear RNase III enzyme Drosha. Emerging evidence suggests that the miRNA biogenic cascade is tightly controlled. However, little is known whether Drosha is regulated. Here we show that Drosha is targeted by stress. Under stress, p38 MAPK directly phosphorylates Drosha at its N-terminus. This reduces its interaction with DiGeorge syndrome critical region 8, and promotes its nuclear export and degradation by calpain. This regulatory mechanism mediates stress-induced inhibition of Drosha function. Reduction of Drosha sensitizes cells to stress and increases death. In contrast, increase in Drosha attenuates stress-induced death. These findings reveal a critical regulatory mechanism by which stress engages p38 MAPK pathway to destabilize Drosha and inhibit Drosha-mediated cellular survival. PMID:25699712

  19. p38 MAP Kinase Links CAR Activation and Inactivation in the Nucleus via Phosphorylation at Threonine 38

    PubMed Central

    Hori, Takeshi; Moore, Rick

    2016-01-01

    Nuclear receptor constitutive androstane receptor (CAR, NR1I3), which regulates hepatic drug and energy metabolisms as well as cell growth and death, is sequestered in the cytoplasm as its inactive form phosphorylated at threonine 38. CAR activators elicit dephosphorylation, and nonphosphorylated CAR translocates into the nucleus to activate its target genes. CAR was previously found to require p38 mitogen-activated protein kinase (MAPK) to transactivate the cytochrome P450 2B (CYP2B) genes. Here we have demonstrated that p38 MAPK forms a complex with CAR, enables it to bind to the response sequence, phenobarbital-responsive enhancer module (PBREM), within the CYP2B promoter, and thus recruits RNA polymerase II to activate transcription. Subsequently, p38 MAPK elicited rephosphorylation of threonine 38 to inactivate CAR and exclude it from the nucleus. Thus, nuclear p38 MAPK exerted dual regulation by sequentially activating and inactivating CAR-mediated transcription through phosphorylation of threonine 38. PMID:27074912

  20. Targeting Human Central Nervous System Protein Kinases: An Isoform Selective p38αMAPK Inhibitor That Attenuates Disease Progression in Alzheimer’s Disease Mouse Models

    PubMed Central

    2015-01-01

    The first kinase inhibitor drug approval in 2001 initiated a remarkable decade of tyrosine kinase inhibitor drugs for oncology indications, but a void exists for serine/threonine protein kinase inhibitor drugs and central nervous system indications. Stress kinases are of special interest in neurological and neuropsychiatric disorders due to their involvement in synaptic dysfunction and complex disease susceptibility. Clinical and preclinical evidence implicates the stress related kinase p38αMAPK as a potential neurotherapeutic target, but isoform selective p38αMAPK inhibitor candidates are lacking and the mixed kinase inhibitor drugs that are promising in peripheral tissue disease indications have limitations for neurologic indications. Therefore, pursuit of the neurotherapeutic hypothesis requires kinase isoform selective inhibitors with appropriate neuropharmacology features. Synaptic dysfunction disorders offer a potential for enhanced pharmacological efficacy due to stress-induced activation of p38αMAPK in both neurons and glia, the interacting cellular components of the synaptic pathophysiological axis, to be modulated. We report a novel isoform selective p38αMAPK inhibitor, MW01-18-150SRM (=MW150), that is efficacious in suppression of hippocampal-dependent associative and spatial memory deficits in two distinct synaptic dysfunction mouse models. A synthetic scheme for biocompatible product and positive outcomes from pharmacological screens are presented. The high-resolution crystallographic structure of the p38αMAPK/MW150 complex documents active site binding, reveals a potential low energy conformation of the bound inhibitor, and suggests a structural explanation for MW150’s exquisite target selectivity. As far as we are aware, MW150 is without precedent as an isoform selective p38MAPK inhibitor or as a kinase inhibitor capable of modulating in vivo stress related behavior. PMID:25676389

  1. Sulfur mustard primes human neutrophils for increased degranulation and stimulates cytokine release via TRPM2/p38 MAPK signaling

    SciTech Connect

    Ham, Hwa-Yong; Hong, Chang-Won; Lee, Si-Nae; Kwon, Min-Soo; Kim, Yeon-Ja; Song, Dong-Keun

    2012-01-01

    Sulfur mustard (2,2′-bis-chloroethyl-sulfide; SM) has been a military threat since the World War I. The emerging threat of bioterrorism makes SM a major threat not only to military but also to civilian world. SM injury elicits an inflammatory response characterized by infiltration of neutrophils. Although SM was reported to prime neutrophils, the mechanism has not been identified yet. In the present study, we investigated the mechanism of SM-induced priming in human neutrophils. SM increased [Ca{sup 2+}]{sub i} in human neutrophils in a concentration-dependent fashion. Transient receptor potential melastatin (TRPM) 2 inhibitors (clotrimazole, econazole and flufenamic acid) and silencing of TRPM2 by shRNA attenuated SM-induced [Ca{sup 2+}]{sub i} increase. SM primed degranulation of azurophil and specific granules in response to activation by fMLP as previously reported. SB203580, an inhibitor of p38 MAPK, inhibited SM-induced priming. Neither PD98057, an ERK inhibitor, nor SP600215, a JNK inhibitor, inhibited SM-induced priming. In addition, SM enhanced phosphorylation of NF-kB p65 and release of TNF-α, interleukin (IL)-6 and IL-8. SB203580 inhibited SM-induced NF-kB phosphorylation and cytokine release. These results suggest the involvement of TRPM2/p38 MAPK pathway in SM-induced priming and cytokines release in neutrophils. -- Highlights: ► SM increased [Ca{sup 2+}]{sub i} in human neutrophils through TPRM2-mediated calcium influx. ► SM primed degranulation of azurophil and specific granules. ► SM enhanced p38 MAPK and NF-κB p65 phosphorylation in human neutrophils. ► SM enhanced release of TNF-α, interleukin (IL)-6 and IL-8 from human neutrophils. ► SB203580 inhibited SM-induced priming, NF-κB p65 phosphorylation and cytokine release.

  2. Characterization of three mitogen-activated protein kinases (MAPK) genes reveals involvement of ERK and JNK, not p38 in defense against bacterial infection in Yesso scallop Patinopecten yessoensis.

    PubMed

    Sun, Yan; Zhang, Lingling; Zhang, Meiwei; Li, Ruojiao; Li, Yangping; Hu, Xiaoli; Wang, Shi; Bao, Zhenmin

    2016-07-01

    Mitogen-activated protein kinases (MAPKs) are protein Ser/Thr kinases that play a vital role in innate immune responses by converting extracellular stimuli into a wide range of cellular responses. Although MAPKs have been extensively studied in various vertebrates and invertebrates, our current understanding of MAPK signaling cascade in scallop is in its infancy. In this study, three MAPK genes (PyERK, PyJNK, and Pyp38) were identified from Yesso scallop Patinopecten yessoensis. The open reading frame of PyERK, PyJNK, and Pyp38 was 1104, 1227, and 1104 bp, encoding 367, 408, and 367 amino acids, respectively. Conservation in some splicing sites was revealed across the three PyMAPKs, suggesting the common descent of MAPKs genes. The expression profiles of PyMAPKs over the course of ten different developmental stages showed that they had different expression patterns. In adult scallops, PyMAPKs were primarily expressed in muscles, hemocytes, gill, and mantle. To gain insights into their role in innate immunity, we investigated their expression profiles after infection with Gram-positive bacteria (Micrococcus luteus) and Gram-negative bacteria (Vibrio anguillarum). Significant difference in gene expression was only found in PyERK and PyJNK, but not Pyp38, suggesting Pyp38 may not participate in immune response to bacterial infection. Besides, PyERK and PyJNK exhibited more drastic change against the invasion of V. anguillarum than M. luteus, suggesting they could be more sensitive to Gram-negative bacteria than Gram-positive bacteria. This study provides valuable resource for elucidating the role of MAPK signal pathway in bivalve innate immune response. PMID:27155450

  3. Kazinol-P from Broussonetia kazinoki enhances skeletal muscle differentiation via p38MAPK and MyoD.

    PubMed

    Hwang, Jeongmi; Lee, Sang-Jin; Yoo, Miran; Go, Ga-Yeon; Lee, Da Yeon; Kim, Yong-Kee; Seo, Dong-Wan; Kang, Jong-Sun; Ryu, Jae-Ha; Bae, Gyu-Un

    2015-01-01

    The activation of MyoD family transcription factors is critical for myogenic differentiation, which is fundamental to the regeneration of skeletal muscle after injury. Kazinol-P (KP) from Broussonetia kazinoki (B. kazinoki), a natural compound, has been reported to possess an anti-oxidant function. In a screen of natural compounds for agonists of the MyoD activity, we identified KP and examined its effect on myoblast differentiation. Consistently, KP enhanced the myotube formation, accompanied with upregulation of myogenic markers such as MHC, Myogenin and Troponin-T. KP treatment in C2C12 myoblasts led to strong activation of a key promyogenic kinase p38MAPK in a dose, and time-dependent manner. Furthermore, KP treatment enhanced the MyoD-mediated trans-differentiation of 10T1/2 fibroblasts into myoblasts. Taken together, KP promotes myogenic differentiation through activation of p38MAPK and MyoD transcription activities. Thus KP may be a potential therapeutic candidate to prevent fibrosis and improve muscle regeneration and repair.

  4. Diarachidonoylphosphoethanolamine induces apoptosis of malignant pleural mesothelioma cells through a Trx/ASK1/p38 MAPK pathway.

    PubMed

    Tsuchiya, Ayako; Kaku, Yoshiko; Nakano, Takashi; Nishizaki, Tomoyuki

    2015-11-01

    1,2-Diarachidonoyl-sn-glycero-3-phosphoethanolamine (DAPE) induces both necrosis/necroptosis and apoptosis of NCI-H28 malignant pleural mesothelioma (MPM) cells. The present study was conducted to understand the mechanism for DAPE-induced apoptosis of NCI-H28 cells. DAPE induced caspase-independent apoptosis of NCI-H28 malignant pleural mesothelioma (MPM) cells, and the effect of DAPE was prevented by antioxidants or an inhibitor of NADPH oxidase (NOX). DAPE generated reactive oxygen species (ROS) and inhibited activity of thioredoxin (Trx) reductase (TrxR). DAPE decreased an association of apoptosis signal-regulating kinase 1 (ASK1) with thioredoxin (Trx), thereby releasing ASK1. DAPE activated p38 mitogen-activated protein kinase (MAPK), which was inhibited by an antioxidant or knocking-down ASK1. In addition, DAPE-induced NCI-H28 cell death was also prevented by knocking-down ASK1. Taken together, the results of the present study indicate that DAPE stimulates NOX-mediated ROS production and suppresses TrxR activity, resulting in the decrease of reduced Trx and the dissociation of ASK1 from a complex with Trx, allowing sequential activation of ASK1 and p38 MAPK, to induce apoptosis of NCI-H28 MPM cells.

  5. Induction of Rad51 protein levels by p38 MAPK decreases cytotoxicity and mutagenicity in benzo[a]pyrene-exposed human lung cancer cells

    SciTech Connect

    Chuang, S.-M.; Wang, L.-H.; Hong, J.-H.; Lin, Y.-W.

    2008-08-01

    Rad51 is an essential component of the homologous recombination repair pathway. Abnormal expression of Rad51 has been reported in various carcinomas. Benzo[a]pyrene (B[a]P), a polycyclic hydrocarbon carcinogen found in the environment, induces cancer in multiple organs. B[a]P has been shown to activate the p38 MAPK signaling pathway in mammalian cells. The prime purpose of this study was to determine how B[a]P activates the p38 MAPK signaling pathway, and how this then regulates Rad51 expression in human cancer cells. Exposure of human lung cancer cells with B[a]P increased Rad51 protein levels in a time- and dose-dependent fashion. B[a]P also induced Rad51 mRNA and protein synthesis. Blockage of p38 MAPK activation by SB202190 or small interfering RNA (si-p38) decreased B[a]P-elicited Rad51 protein levels by increasing Rad51 protein instability, but did not affect Rad51 mRNA transcription. Furthermore, enhancement of p38 MAPK signaling by constitutively active MKK6 (MKK6E) increased Rad51 protein levels and protein stability. Moreover, B[a]P-induced cytotoxicity and mutagenicity were significantly increased in cells depleted of endogenous Rad51. Taken together, these results indicate that Rad51 protein provides a critical role in inhibiting the cytotoxicity and mutagenicity of B[a]P in B[a]P-treated human lung cancer cells. Furthermore, the work points to an unexpected role of p38 MAPK signaling in the control of Rad51 protein stability in response to B[a]P exposure.

  6. STAT1, STAT3 and p38MAPK are involved in the apoptotic effect induced by a chimeric cyclic interferon-{alpha}2b peptide

    SciTech Connect

    Blank, Viviana C.; Pena, Clara; Roguin, Leonor P.

    2010-02-15

    In the search of mimetic peptides of the interferon-{alpha}2b molecule (IFN-{alpha}2b), we have previously designed and synthesized a chimeric cyclic peptide of the IFN-{alpha}2b that inhibits WISH cell proliferation by inducing an apoptotic response. Here, we first studied the ability of this peptide to activate intracellular signaling pathways and then evaluated the participation of some signals in the induction of apoptosis. Stimulation of WISH cells with the cyclic peptide showed tyrosine phosphorylation of Jak1 and Tyk2 kinases, tyrosine and serine phosphorylation of STAT1 and STAT3 transcription factors and activation of p38 MAPK pathway, although phosphorylation levels or kinetics were in some conditions different to those obtained under IFN-{alpha}2b stimulus. JNK and p44/42 pathways were not activated by the peptide in WISH cells. We also showed that STAT1 and STAT3 downregulation by RNA interference decreased the antiproliferative activity and the amount of apoptotic cells induced by the peptide. Pharmacological inhibition of p38 MAPK also reduced the peptide growth inhibitory activity and the apoptotic effect. Thus, we demonstrated that the cyclic peptide regulates WISH cell proliferation through the activation of Jak/STAT signaling pathway. In addition, our results indicate that p38 MAPK may also be involved in cell growth regulation. This study suggests that STAT1, STAT3 and p38 MAPK would be mediating the antitumor and apoptotic response triggered by the cyclic peptide in WISH cells.

  7. Pro-oncogenic role of alternative p38 mitogen-activated protein kinases p38γ and p38δ, linking inflammation and cancer in colitis-associated colon cancer.

    PubMed

    Del Reino, Paloma; Alsina-Beauchamp, Dayanira; Escós, Alejandra; Cerezo-Guisado, Ma Isabel; Risco, Ana; Aparicio, Noelia; Zur, Rafal; Fernandez-Estévez, Marian; Collantes, Elena; Montans, Jose; Cuenda, Ana

    2014-11-01

    p38 MAPK signaling has been implicated in the regulation of processes leading to cancer development and progression. Chronic inflammation is a known risk factor for tumorigenesis, yet the precise mechanism of this association remains largely unknown. The related p38αMAPK (MAPK14) proteins p38γ (MAPK12) and p38δ (MAPK13) were recently shown to modulate the immune response, although their role in tumorigenesis remains controversial and their function in inflammation-associated cancer has not been studied. We analyzed the role of p38γ and p38δ in colon cancer associated to colitis using the azoxymethane/dextran sodium sulphate (AOM/DSS) colitis-associated colon cancer model in wild-type (WT), p38γ-, p38δ-, and p38γ/δ-deficient (p38γ/δ(-/-)) mice. We found that p38γ/δ deficiency significantly decreased tumor formation, in parallel with a decrease in proinflammatory cytokine and chemokine production. Analysis of leukocyte populations in p38γ/δ(-/-) mouse colon showed less macrophage and neutrophil recruitment than in WT mice. Furthermore, WT chimeric mice with transplanted p38γ/δ(-/-) bone marrow had less tumors than WT mice transplanted with WT bone marrow, whereas tumor number was significantly increased in p38γ/δ(-/-) chimeric mice with WT bone marrow compared with p38γ/δ(-/-) mice transplanted with p38γ/δ(-/-) bone marrow. Together, our results establish that p38γ and p38δ are central to colitis-associated colon cancer formation through regulation of hematopoietic cell response to injury, and validate p38γ and p38δ as potential targets for cancer therapy.

  8. Astragalus Polysaccharide Suppresses Doxorubicin-Induced Cardiotoxicity by Regulating the PI3k/Akt and p38MAPK Pathways

    PubMed Central

    Cao, Yuan; Ruan, Yang; Shen, Tao; Huang, Xiuqing; Li, Meng; Yu, Weiwei; Zhu, Yuping; Man, Yong; Wang, Shu; Li, Jian

    2014-01-01

    Background. Doxorubicin, a potent chemotherapeutic agent, is associated with acute and chronic cardiotoxicity, which is cumulatively dose-dependent. Astragalus polysaccharide (APS), the extract of Astragalus membranaceus with strong antitumor and antiglomerulonephritis activity, can effectively alleviate inflammation. However, whether APS could ameliorate chemotherapy-induced cardiotoxicity is not understood. Here, we investigated the protective effects of APS on doxorubicin-induced cardiotoxicity and elucidated the underlying mechanisms of the protective effects of APS. Methods. We analyzed myocardial injury in cancer patients who underwent doxorubicin chemotherapy and generated a doxorubicin-induced neonatal rat cardiomyocyte injury model and a mouse heart failure model. Echocardiography, reactive oxygen species (ROS) production, TUNEL, DNA laddering, and Western blotting were performed to observe cell survival, oxidative stress, and inflammatory signal pathways in cardiomyocytes. Results. Treatment of patients with the chemotherapeutic drug doxorubicin led to heart dysfunction. Doxorubicin reduced cardiomyocyte viability and induced C57BL/6J mouse heart failure with concurrent elevated ROS generation and apoptosis, which, however, was attenuated by APS treatment. In addition, there was profound inhibition of p38MAPK and activation of Akt after APS treatment. Conclusions. These results demonstrate that APS could suppress oxidative stress and apoptosis, ameliorating doxorubicin-mediated cardiotoxicity by regulating the PI3k/Akt and p38MAPK pathways. PMID:25386226

  9. Role of p38 Mapk in development of acute hepatic injury in Long-Evans Cinnamon (LEC) rats, an animal model of human Wilson's disease.

    PubMed

    Kadowaki, Shingo; Meguro, Saori; Imaizumi, Yoshitaka; Sakai, Hiroshi; Endoh, Daiji; Hayashi, Masanobu

    2013-12-30

    The Long-Evans Cinnamon (LEC) rat, an animal model of human Wilson's disease, spontaneously develops fulminant hepatitis associated with severe jaundice at about 4 months of age. In this study, we examined the changes in gene expression during progression of acute hepatic injury. When levels of gene expression in the liver of LEC rats at 13 weeks of age were compared to those in rats at 4 weeks of age using oligonucleotide arrays, 1,620 genes out of 7,700 genes analyzed showed more than 2-fold differences. Expression levels of 11 of 29 genes related to stress-activating protein kinase (SAPK) changed by more than 2-fold in the liver of LEC rats, but none of the SAPK-related genes showed changes in expression levels in the liver of control rats. Activity of p38 mapk in the liver of LEC rats at 13 weeks of age was about 8.1-fold higher than that in rats at 4 weeks of age. When LEC rats were administered SB203580, a p38 mapk-specific inhibitor, by s.c. injection twice a week from 10 to 13 weeks of age, activities of p38 mapk in the liver, activities of AST and ALT and concentrations of bilirubin in sera of rats administered SB203580 significantly decreased compared to those in rats not administered. These results showed that the increase in activities of p38 mapk was related to the occurrence of acute hepatic injury in LEC rats.

  10. Quinpirole Increases Melatonin-Augmented Pentobarbital Sleep via Cortical ERK, p38 MAPK, and PKC in Mice.

    PubMed

    Hong, Sa-Ik; Kwon, Seung-Hwan; Hwang, Ji-Young; Ma, Shi-Xun; Seo, Jee-Yeon; Ko, Yong-Hyun; Kim, Hyoung-Chun; Lee, Seok-Yong; Jang, Choon-Gon

    2016-03-01

    Sleep, which is an essential part of human life, is modulated by neurotransmitter systems, including gamma-aminobutyric acid (GABA) and dopamine signaling. However, the mechanisms that initiate and maintain sleep remain obscure. In this study, we investigated the relationship between melatonin (MT) and dopamine D2-like receptor signaling in pentobarbital-induced sleep and the intracellular mechanisms of sleep maintenance in the cerebral cortex. In mice, pentobarbital-induced sleep was augmented by intraperitoneal administration of 30 mg/kg MT. To investigate the relationship between MT and D2-like receptors, we administered quinpirole, a D2-like receptor agonist, to MT- and pentobarbital-treated mice. Quinpirole (1 mg/kg, i.p.) increased the duration of MT-augmented sleep in mice. In addition, locomotor activity analysis showed that neither MT nor quinpirole produced sedative effects when administered alone. In order to understand the mechanisms underlying quinpirole-augmented sleep, we measured protein levels of mitogen-activated protein kinases (MAPKs) and cortical protein kinases related to MT signaling. Treatment with quinpirole or MT activated extracellular-signal-regulated kinase 1 and 2 (ERK1/2), p38 MAPK, and protein kinase C (PKC) in the cerebral cortex, while protein kinase A (PKA) activation was not altered significantl. Taken together, our results show that quinpirole increases the duration of MT-augmented sleep through ERK1/2, p38 MAPK, and PKC signaling. These findingssuggest that modulation of D2-like receptors might enhance the effect of MT on sleep. PMID:26902082

  11. Hesperetin Inhibits Vascular Formation by Suppressing of the PI3K/AKT, ERK, and p38 MAPK Signaling Pathways.

    PubMed

    Kim, Gi Dae

    2014-12-01

    Hesperetin has been shown to possess a potential anti-angiogenic effect, including vascular formation by endothelial cells. However, the mechanisms underlying the potential anti-angiogenic activity of hesperetin are not fully understood. In the present study, we evaluated whether hesperetin has anti-angiogenic effects in human umbilical vascular endothelial cells (HUVECs). HUVECs were treated with 50 ng/mL vascular endothelial growth factor (VEGF) to induce proliferation as well as vascular formation, followed by treatment with several doses of hesperetin (25, 50, and 100 μM) for 24 h. Cell proliferation and vascular formation were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and tube formation assay, respectively. In addition, cell signaling related to cell proliferation and vascular formation was analyzed by western blot. Furthermore, a mouse aorta ring assay was performed to confirm the effect of hesperetin on vascular formation. Hesperetin treatment did not cause differences in HUVECs proliferation. However, hesperetin significantly inhibited VEGF-induced cell migration and tube formation of HUVECs (P<0.05). Moreover, hesperetin suppressed the expression of ERK, p38 MAPK, and PI3K/AKT in the VEGF-induced HUVECs. In an ex vivo model, hesperetin also suppressed microvessel sprouting of mouse aortic rings. Taken together, the findings suggest that hesperetin inhibited vascular formation by endothelial cells via the inhibition of the PI3K/AKT, ERK and p38 MAPK signaling.

  12. Nobiletin protects against murine l-arginine-induced acute pancreatitis in association with downregulating p38MAPK and AKT.

    PubMed

    Liu, Bing; Huang, Jian; Zhang, Bin

    2016-07-01

    Acute pancreatitis (AP) is an inflammatory disease characterized by acinar cell damage, oxidative stress, and inflammation of the pancreas. Nobiletin (3',4',5,6,7,8-hexamethoxyflavone), a major polymethoxy flavone, has shown health-promoting properties in previous studies. Therefore, in this study, we investigated whether nobiletin protects against experimental AP induced with l-arginine. C57BL/6 mice were treated with 25 or 50mg/kg nobiletin by intraperitoneal injection once daily for 14 consecutive days. AP was then induced in the mice with two intraperitoneal injections of l-arginine (4g/kg). The nobiletin treatment significantly reduced the plasma amylase levels, pancreatic myeloperoxidase activity, percentage of pancreatic necrosis, plasma proinflammatory factors, the generation of reactive oxygen species, cell apoptosis, tissue damage, and the expression of phosphorylated p38MAPK (p-p38MAPK) and p-AKT. These results suggest that nobiletin is a new therapeutic method for l-arginine-induced AP in mice.

  13. Nitric oxide induces prion protein via MEK and p38 MAPK signaling.

    PubMed

    Wang, Vinchi; Chuang, Tzu-Chao; Hsu, Yaw-Don; Chou, Wei-Yuan; Kao, Ming-Ching

    2005-07-22

    The prion diseases or transmissible spongiform encephalopathy, such as human Creutzfeldt-Jakob disease (CJD) and so-called mad cow disease, are attributed to the causative agent, the scrapie variant of prion protein (PrP(Sc)) which causes fatal neurodegeneration. To investigate if stresses such as nitric oxide (NO) induced the cellular isoform of prion protein (PrP(C)), lipopolysaccharide, and sodium nitroprusside were used to treat N2a and NT2 cells, which resulted in elevated levels of the PRNP mRNA and prion protein. The signaling pathway for the NO-induced PrP(C) production involved guanylyl cyclase, MEK, and p38 MAPK as shown by the effect of specific pharmacological inhibitors ODQ, PD98059, and SB203580, respectively. Knowing the PrP induction by the biologically existing stimulus, this study provides useful information about the possible cellular mechanism and strategies for the treatment of CJD. PMID:15936714

  14. Inhibitory effects of enalaprilat on rat cardiac fibroblast proliferation via ROS/P38MAPK/TGF-β1 signaling pathway.

    PubMed

    Yu, Min; Zheng, Yang; Sun, Hong-Xia; Yu, Du-Juan

    2012-01-01

    Enalaprilat (Ena.), an angiotensin II (Ang II) converting enzyme inhibitor (ACEI), can produce some therapeutic effects on hypertension, ventricular hypertrophy and myocardial remodeling in clinic, but its precise mechanism, especially its signaling pathways remain elusive. In this study, cardiac fibroblasts (CFb) was isolated by the trypsin digestion method; a BrdU proliferation assay was adopted to determine cell proliferation; an immunofluorescence assay was used to measure intracellular reactive oxygen species (ROS); immunocytochemistry staining and Western blotting assay were used to detect phosphorylated p38 mitogen activated protein kinase (p-p38MAPK) and transforming growth factor-β(1) (TGF-β(1)) protein expression, respectively. The results showed that Ang II (10(-7) M) stimulated the cardiac fibroblast proliferation which was inhibited by NAC (an antioxidant), SB203580 (a p38MAPK inhibitor) or enalaprilat; Ang II caused an burst of intracellular ROS level within thirty minutes, an increase in p-p38MAPK (3.6-fold of that in the control group), as well as an elevation of TGF-β(1) meantime; NAC, an antioxidant, and enalaprilat treatment attenuated cardiac fibroblast proliferation induced by Ang II and decreased ROS and p-p38MAPK protein levels in rat cardiac fibroblast; SB203580 lowered TGF-β(1) protein expression in rats' CFb in a dose-dependent manner. It could be concluded that enalaprilat can inhibit the cardiac fibroblast proliferation induced by Ang II via blocking ROS/P38MAPK/TGF-β(1) signaling pathways and the study provides a theoretical proof for the application of ACEIs in treating myocardial fibrosis and discovering the primary mechanism through which ACEIs inhibit CFb proliferation. PMID:22395404

  15. Flow Cytometric Detection of p38 MAPK Phosphorylation and Intracellular Cytokine Expression in Peripheral Blood Subpopulations from Patients with Autoimmune Rheumatic Diseases

    PubMed Central

    Mavropoulos, Athanasios; Bogdanos, Dimitrios P.; Liaskos, Christos; Sakkas, Lazaros I.; Rigopoulou, Eirini I.

    2014-01-01

    Flow cytometric analysis of p38 mitogen-activated protein kinase (p38 MAPK) signaling cascade is optimally achieved by methanol permeabilization protocols. Such protocols suffer from the difficulties to accurately detect intracellular cytokines and surface epitopes of infrequent cell subpopulations, which are removed by methanol. To overcome these limitations, we have modified methanol-based phosphoflow protocols using several commercially available antibody clones suitable for surface antigens, intracellular cytokines, and p38 MAPK. These included markers of B cells (CD19, CD20, and CD22), T cells (CD3, CD4, and CD8), NK (CD56 and CD7), and dendritic cells (CD11c). We have also tested surface markers of costimulatory molecules, such as CD27. We have successfully determined simultaneous expression of IFN-γ, as well as IL-10, and phosphorylated p38 in cell subsets. The optimized phosphoflow protocol has also been successfully applied in peripheral blood mononuclear cells or purified cell subpopulations from patients with various autoimmune diseases. In conclusion, our refined phosphoflow cytometric approach allows simultaneous detection of p38 MAPK activity and intracellular cytokine expression and could be used as an important tool to study signaling cascades in autoimmunity. PMID:24741615

  16. 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.

  17. 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. PMID:27570977

  18. 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

  19. Gastrointestinal Congestion Dilates the Hepatic Artery Through the P38 MAPK Signal Transduction Pathway During Liver Transplantation.

    PubMed

    Cao, Zhongping; Tang, Xiaowen; Hou, Shike

    2016-01-01

    During the neohepatic stage of liver transplantation, hemodynamics change markedly. The current study aimed to investigate whether gastrointestinal congestion caused by inferior vena cava and hepatic portal vein clamping can dilate the hepatic artery and to determine the associated mechanisms. Ring segments of the hepatic artery were treated with the plasma from gastrointestinal congestion or the superior vena cava. The fractions in gastrointestinal congestion and the superior vena cava plasma were tested, and the effect of these fractions on the tone of the hepatic artery ring was examined. Different signal transduction blockers and different inhibitors were then used to determine the exact signal transduction pathway involved. In addition, endothelial cell structure was observed by transmission electron microscopy after treatment with the gastrointestinal congestion plasma or the superior vena cava plasma. Gastrointestinal congestion plasma contained more inflammatory cytokines than superior vena cava plasma, and these cytokines could cause hepatic artery ring dilatation. A P38 mitogen-activated protein kinase (P38 MAPK) signal transduction pathway blocker and nitric oxide (NO), prostaglandin (PGI2), nuclear factor-κB (NF-κB), and adenosine triphosphate (ATP)-sensitive K (KATP) channel inhibitors were able to significantly reverse the ring tension caused by gastrointestinal congestion plasma. The normal endothelium was also injured by treatment with gastrointestinal congestion plasma. The inflammatory cytokines in gastrointestinal congestion can cause hepatic artery ring dilatation through the P38 MAPK signal transduction pathway, and this phenomenon is also associated with NO, PGI2, NF-κB, and the KATP channel. These inflammatory cytokines can injure endothelial cells in the hepatic artery. PMID:26955003

  20. Taurine prevents arsenic-induced cardiac oxidative stress and apoptotic damage: Role of NF-{kappa}B, p38 and JNK MAPK pathway

    SciTech Connect

    Ghosh, Jyotirmoy; Das, Joydeep; Manna, Prasenjit

    2009-10-01

    Cardiac dysfunction is a major cause of morbidity and mortality worldwide due to its complex pathogenesis. However, little is known about the mechanism of arsenic-induced cardiac abnormalities and the use of antioxidants as the possible protective agents in this pathophysiology. Conditionally essential amino acid, taurine, accounts for 25% to 50% of the amino acid pool in myocardium and possesses antioxidant properties. The present study has, therefore, been carried out to investigate the underlying mechanism of the beneficial role of taurine in arsenic-induced cardiac oxidative damage and cell death. Arsenic reduced cardiomyocyte viability, increased reactive oxygen species (ROS) production and intracellular calcium overload, and induced apoptotic cell death by mitochondrial dependent caspase-3 activation and poly-ADP ribose polymerase (PARP) cleavage. These changes due to arsenic exposure were found to be associated with increased IKK and NF-{kappa}B (p65) phosphorylation. Pre-exposure of myocytes to an IKK inhibitor (PS-1145) prevented As-induced caspase-3 and PARP cleavage. Arsenic also markedly increased the activity of p38 and JNK MAPKs, but not ERK to that extent. Pre-treatment with SP600125 (JNK inhibitor) and SB203580 (p38 MAPK inhibitor) attenuated NF-{kappa}B and IKK phosphorylation indicating that p38 and JNK MAPKs are mainly involved in arsenic-induced NF-{kappa}B activation. Taurine treatment suppressed these apoptotic actions, suggesting that its protective role in arsenic-induced cardiomyocyte apoptosis is mediated by attenuation of p38 and JNK MAPK signaling pathways. Similarly, arsenic intoxication altered a number of biomarkers related to cardiac oxidative stress and other apoptotic indices in vivo and taurine supplementation could reduce it. Results suggest that taurine prevented arsenic-induced myocardial pathophysiology, attenuated NF-{kappa}B activation via IKK, p38 and JNK MAPK signaling pathways and could possibly provide a protection

  1. p38α MAPK Regulates Lineage Commitment and OPG Synthesis of Bone Marrow Stromal Cells to Prevent Bone Loss under Physiological and Pathological Conditions

    PubMed Central

    Cong, Qian; Jia, Hao; Biswas, Soma; Li, Ping; Qiu, Shoutao; Deng, Qi; Guo, Xizhi; Ma, Gang; Ling Chau, Jenny Fang; Wang, Yibin; Zhang, Zhen-Lin; Jiang, Xinquan; Liu, Huijuan; Li, Baojie

    2016-01-01

    Summary Bone marrow-derived mesenchymal stromal cells (BM-MSCs) are capable of differentiating into osteoblasts, chondrocytes, and adipocytes. Skewed differentiation of BM-MSCs contributes to the pathogenesis of osteoporosis. Yet how BM-MSC lineage commitment is regulated remains unclear. We show that ablation of p38α in Prx1+ BM-MSCs produced osteoporotic phenotypes, growth plate defects, and increased bone marrow fat, secondary to biased BM-MSC differentiation from osteoblast/chondrocyte to adipocyte and increased osteoclastogenesis and bone resorption. p38α regulates BM-MSC osteogenic commitment through TAK1-NF-κB signaling and osteoclastogenesis through osteoprotegerin (OPG) production by BM-MSCs. Estrogen activates p38α to maintain OPG expression in BM-MSCs to preserve the bone. Ablation of p38α in BM-MSCs positive for Dermo1, a later BM-MSC marker, only affected osteogenic differentiation. Thus, p38α mitogen-activated protein kinase (MAPK) in Prx1+ BM-MSCs acts to preserve the bone by promoting osteogenic lineage commitment and sustaining OPG production. This study thus unravels previously unidentified roles for p38α MAPK in skeletal development and bone remodeling. PMID:26947973

  2. RhoA-ROCK and p38MAPK-MSK1 mediate vitamin D effects on gene expression, phenotype, and Wnt pathway in colon cancer cells.

    PubMed

    Ordóñez-Morán, Paloma; Larriba, María Jesús; Pálmer, Héctor G; Valero, Ruth A; Barbáchano, Antonio; Duñach, Mireia; de Herreros, Antonio García; Villalobos, Carlos; Berciano, María Teresa; Lafarga, Miguel; Muñoz, Alberto

    2008-11-17

    The active vitamin D metabolite 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) inhibits proliferation and promotes differentiation of colon cancer cells through the activation of vitamin D receptor (VDR), a transcription factor of the nuclear receptor superfamily. Additionally, 1,25(OH)(2)D(3) has several nongenomic effects of uncertain relevance. We show that 1,25(OH)(2)D(3) induces a transcription-independent Ca(2+) influx and activation of RhoA-Rho-associated coiled kinase (ROCK). This requires VDR and is followed by activation of the p38 mitogen-activated protein kinase (p38MAPK) and mitogen- and stress-activated kinase 1 (MSK1). As shown by the use of chemical inhibitors, dominant-negative mutants and small interfering RNA, RhoA-ROCK, and p38MAPK-MSK1 activation is necessary for the induction of CDH1/E-cadherin, CYP24, and other genes and of an adhesive phenotype by 1,25(OH)(2)D(3). RhoA-ROCK and MSK1 are also required for the inhibition of Wnt-beta-catenin pathway and cell proliferation. Thus, the action of 1,25(OH)(2)D(3) on colon carcinoma cells depends on the dual action of VDR as a transcription factor and a nongenomic activator of RhoA-ROCK and p38MAPK-MSK1.

  3. The Mitogen-Activated Protein Kinase p38α Regulates Tubular Damage in Murine Anti-Glomerular Basement Membrane Nephritis

    PubMed Central

    Müller, Ralf; Daniel, Christoph; Hugo, Christian; Amann, Kerstin; Mielenz, Dirk; Endlich, Karlhans; Braun, Tobias; van der Veen, Betty; Heeringa, Peter; Schett, Georg; Zwerina, Jochen

    2013-01-01

    p38 mitogen-activated protein kinase (MAPK) is thought to play a central role in acute and chronic inflammatory responses. Whether p38MAPK plays a pathogenic role in crescentic GN (GN) and which of its four isoforms is preferentially involved in kidney inflammation is not definitely known. We thus examined expression and activation of p38MAPK isoforms during anti-glomerular basement membrane (GBM) nephritis. Therefore, p38α conditional knockout mice (MxCre-p38αΔ/Δ) were used to examine the role of p38α in anti-GBM induced nephritis. Both wild type and MxCre-p38αΔ/Δ mice developed acute renal failure over time. Histological examinations revealed a reduced monocyte influx and less tubular damage in MxCre-p38αΔ/Δ mice, whereas glomerular crescent formation and renal fibrosis was similar. Likewise, the levels of pro- and anti-inflammatory cytokines such as TNF, IL-1 and IL-10 were similar, but IL-8 was even up-regulated in MxCre-p38αΔ/Δ mice. In contrast, we could detect strong down-regulation of chemotactic cytokines such as CCL-2, -5 and -7, in the kidneys of MxCre-p38αΔ/Δ mice. In conclusion, p38α is the primary p38MAPK isoform expressed in anti-GBM nephritis and selectively affects inflammatory cell influx and tubular damage. Full protection from nephritis is however not achieved as renal failure and structural damage still occurs. PMID:23441175

  4. Discovery of biaryl-4-carbonitriles as antihyperglycemic agents that may act through AMPK-p38 MAPK pathway.

    PubMed

    Goel, Atul; Nag, Pankaj; Rahuja, Neha; Srivastava, Rohit; Chaurasia, Sumit; Gautam, Sudeep; Chandra, Sharat; Siddiqi, Mohammad Imran; Srivastava, Arvind K

    2014-08-25

    A series of functionalized biaryl-4-carbonitriles was synthesized in three steps and evaluated for PTP-1B inhibitory activity. Among the synthesized compounds, four biaryls 6a-d showed inhibition (IC50 58-75 μM) against in vitro PTP-1B assay possibly due to interaction with amino acid residues Lys120, Tyr46 through hydrogen bonding and aromatic-aromatic interactions, respectively. Two biaryl-4-carbonitriles 6b and 6c showed improved glucose tolerance, fasting as well as postprandial blood glucose, serum total triglycerides, and increased high-density lipoprotein-cholesterol in SLM, STZ, STZ-S and C57BL/KsJ-db/db animal models. The bioanalysis of 4'-bromo-2,3-dimethyl-5-(piperidin-1-yl)biphenyl-4-carbonitrile (6b) revealed that like insulin, it increased 2-deoxyglucose uptake in skeletal muscle cells (L6 and C2C12 myotubes). The compound 6b significantly up-regulated the genes related to the insulin signaling pathways like AMPK, MAPK including glucose transporter-4 (GLUT-4) gene in muscle tissue of C57BL/KsJ-db/db mice. Furthermore, it was observed that the compound 6b up-regulated PPARα, UCP2 and HNF4α, which are key regulator of glucose, lipid, and fatty acid metabolism. Western blot analysis of the compound 6b showed that it significantly increased the phosphorylation of AMPK and p38 MAPK and ameliorated glucose uptake in C57BL/KsJ-db/db mice through the AMPK-p38 MAPK pathway.

  5. Reduced Parasite Motility and Micronemal Protein Secretion by a p38 MAPK Inhibitor Leads to a Severe Impairment of Cell Invasion by the Apicomplexan Parasite Eimeria tenella

    PubMed Central

    Bussière, Françoise I.; Le Vern, Yves; Niepceron, Alisson; Silvestre, Anne; de Sablet, Thibaut; Lacroix-Lamandé, Sonia; Laurent, Fabrice

    2015-01-01

    E. tenella infection is associated with a severe intestinal disease leading to high economic losses in poultry industry. Mitogen activated protein kinases (MAPKs) are implicated in early response to infection and are divided in three pathways: p38, extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK). Our objective was to determine the importance of these kinases on cell invasion by E. tenella. We evaluated the effect of specific inhibitors (ERK: PD98059, JNKII: SP600125, p38 MAPK: SB203580) on the invasion of epithelial cells. Incubation of SP600125 and SB203580 with epithelial cells and parasites significantly inhibited cell invasion with the highest degree of inhibition (90%) for SB203580. Silencing of the host p38α MAPK expression by siRNA led to only 20% decrease in cell invasion. In addition, when mammalian epithelial cells were pre-treated with SB203580, and washed prior infection, a 30% decrease in cell invasion was observed. This decrease was overcome when a p38 MAPK activator, anisomycin was added during infection. This suggests an active but limited role of the host p38 MAPK in this process. We next determined whether SB203580 has a direct effect on the parasite. Indeed, parasite motility and secretion of micronemal proteins (EtMIC1, 2, 3 and 5) that are involved in cell invasion were both decreased in the presence of the inhibitor. After chasing the inhibitor, parasite motility and secretion of micronemal proteins were restored and subsequently cell invasion. SB203580 inhibits cell invasion by acting partly on the host cell and mainly on the parasite. PMID:25689363

  6. Osmotic shrinkage of human cervical cancer cells induces an extracellular Cl- -dependent nonselective cation channel, which requires p38 MAPK.

    PubMed

    Shen, Meng-Ru; Chou, Cheng-Yang; Hsu, Keng-Fu; Ellory, J Clive

    2002-11-29

    This study is to integrate a functional role of nonselective cation (NSC) channels into a model of volume regulation on osmotic shrinkage for human cervical cancer cells. Application of a hypertonic solution (400 mosm kg(-1)) induced cell shrinkage, which was accompanied by a 7-fold increase of inward currents at -80 mV from -4.1 +/- 0.4 pA pF(-1) to -29 +/- 1.1 pA pF(-1) (n = 36, p < 0.001). There is a good correlation of channel activity and cell volume changes. Replacement of bath Na(+) by K(+), Cs(+), Li(+), or Rb(+) did not affect the stimulated inward current significantly, but replacement by Ca(2+), Ba(2+), or the impermeable cation N-methyl-d-glucamine abolished the inward current; this demonstrates that the shrinkage-induced currents discriminate poorly between monovalent cations but are not carried by divalent cations. Replacement of extracellular Cl(-) by gluconate abolished the shrinkage-induced currents in a concentration-dependent manner without changing the reversal potential. Gadolinium (Gd(3+)) inhibited the stimulated current, whereas bumetanide and amiloride had no inhibitory effect. Cell shrinkage triggered mitogen-activated protein (MAP) kinase cascades leading to the activation of MAP/extracellular signal-regulated kinase 1/2 (ERK1/2) kinase (MEK1/2), and p38 kinase. Interference with p38 MAPK by either the specific inhibitor (SB202190), or a dominant-negative mutant profoundly suppressed the activation of the shrinkage-induced NSC channels. In contrast, the regulatory mechanism of shrinkage-induced NSC channels was independent of the volume-responsive MEK1/2 signaling pathway. More importantly, the cell volume response to hypertonicity was inhibited significantly in p38 dominant-negative mutant or by SB202190. Therefore, p38 MAPK is critically involved in the activation of a shrinkage-induced NSC channel, which plays an important role in the volume regulation of human cervical cancer cells. PMID:12226098

  7. p38 mitogen-activated protein kinase activation during platelet storage: consequences for platelet recovery and hemostatic function in vivo

    PubMed Central

    Canault, Matthias; Duerschmied, Daniel; Brill, Alexander; Stefanini, Lucia; Schatzberg, Daphne; Cifuni, Stephen M.

    2010-01-01

    Platelets undergo several modifications during storage that reduce their posttransfusion survival and functionality. One important feature of these changes, which are known as platelet storage lesion, is the shedding of the surface glycoproteins GPIb-α and GPV. We recently demonstrated that tumor necrosis factor-α converting enzyme (TACE/ADAM17) mediates mitochondrial injury-induced shedding of adhesion receptors and that TACE activity correlates with reduced posttransfusion survival of these cells. We now confirm that TACE mediates receptor shedding and clearance of platelets stored for 16 hours at 37°C or 22°C. We further demonstrate that both storage and mitochondrial injury lead to the phosphorylation of p38 mitogen-activated kinase (MAPK) in platelets and that TACE-mediated receptor shedding from mouse and human platelets requires p38 MAP kinase signaling. Protein kinase C, extracellular regulated-signal kinase MAPK, and caspases were not involved in TACE activation. Both inhibition of p38 MAPK and inactivation of TACE during platelet storage led to a markedly improved posttransfusion recovery and hemostatic function of platelets in mice. p38 MAPK inhibitors had only minor effects on the aggregation of fresh platelets under static or flow conditions in vitro. In summary, our data suggest that inhibition of p38 MAPK or TACE during storage may significantly improve the quality of stored platelets. PMID:19965619

  8. p38 mitogen-activated protein kinase activation during platelet storage: consequences for platelet recovery and hemostatic function in vivo.

    PubMed

    Canault, Matthias; Duerschmied, Daniel; Brill, Alexander; Stefanini, Lucia; Schatzberg, Daphne; Cifuni, Stephen M; Bergmeier, Wolfgang; Wagner, Denisa D

    2010-03-01

    Platelets undergo several modifications during storage that reduce their posttransfusion survival and functionality. One important feature of these changes, which are known as platelet storage lesion, is the shedding of the surface glycoproteins GPIb-alpha and GPV. We recently demonstrated that tumor necrosis factor-alpha converting enzyme (TACE/ADAM17) mediates mitochondrial injury-induced shedding of adhesion receptors and that TACE activity correlates with reduced posttransfusion survival of these cells. We now confirm that TACE mediates receptor shedding and clearance of platelets stored for 16 hours at 37 degrees C or 22 degrees C. We further demonstrate that both storage and mitochondrial injury lead to the phosphorylation of p38 mitogen-activated kinase (MAPK) in platelets and that TACE-mediated receptor shedding from mouse and human platelets requires p38 MAP kinase signaling. Protein kinase C, extracellular regulated-signal kinase MAPK, and caspases were not involved in TACE activation. Both inhibition of p38 MAPK and inactivation of TACE during platelet storage led to a markedly improved posttransfusion recovery and hemostatic function of platelets in mice. p38 MAPK inhibitors had only minor effects on the aggregation of fresh platelets under static or flow conditions in vitro. In summary, our data suggest that inhibition of p38 MAPK or TACE during storage may significantly improve the quality of stored platelets.

  9. Transforming growth factor-β1 impairs CFTR-mediated anion secretion across cultured porcine vas deferens epithelial monolayer via the p38 MAPK pathway

    PubMed Central

    Yi, Sheng; Pierucci-Alves, Fernando

    2013-01-01

    The goal of this study was to determine whether transforming growth factor-β1 (TGF-β1) affects epithelial cells lining the vas deferens, an organ that is universally affected in cystic fibrosis male patients. In PVD9902 cells, which are derived from porcine vas deferens epithelium, TGF-β1 exposure significantly reduced short-circuit current (Isc) stimulated by forskolin or a cell membrane-permeant cAMP analog, 8-pCPT-cAMP, suggesting that TGF-β1 affects targets of the cAMP signaling pathway. Electrophysiological results indicated that TGF-β1 reduces the magnitude of current inhibited by cystic fibrosis transmembrane conductance regulator (CFTR) channel blockers. Real-time RT-PCR revealed that TGF-β1 downregulates the abundance of mRNA coding for CFTR, while biotinylation and Western blot showed that TGF-β1 reduces both total CFTR and apical cell surface CFTR abundance. These results suggest that TGF-β1 causes a reduction in CFTR expression, which limits CFTR-mediated anion secretion. TGF-β1-associated attenuation of anion secretion was abrogated by SB431542, a TGF-β1 receptor I inhibitor. Signaling pathway studies showed that the effect of TGF-β1 on Isc was reduced by SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK). TGF-β1 exposure also increased the amount of phospho-p38 MAPK substantially. In addition, anisomycin, a p38 MAPK activator, mimicked the effect of TGF-β1, which further suggests that TGF-β1 affects PVD9902 cells through a p38 MAPK pathway. These observations suggest that TGF-β1, via TGF-β1 receptor I and p38 MAPK signaling, reduces CFTR expression to impair CFTR-mediated anion secretion, which would likely compound the effects associated with mild CFTR mutations and ultimately would compromise male fertility. PMID:23903699

  10. Zinc deficiency exacerbates while zinc supplement attenuates cardiac hypertrophy in high-fat diet-induced obese mice through modulating p38 MAPK-dependent signaling.

    PubMed

    Wang, Shudong; Luo, Manyu; Zhang, Zhiguo; Gu, Junlian; Chen, Jing; Payne, Kristen McClung; Tan, Yi; Wang, Yuehui; Yin, Xia; Zhang, Xiang; Liu, Gilbert C; Wintergerst, Kupper; Liu, Quan; Zheng, Yang; Cai, Lu

    2016-09-01

    Childhood obesity often leads to cardiovascular diseases, such as obesity-related cardiac hypertrophy (ORCH), in adulthood, due to chronic cardiac inflammation. Zinc is structurally and functionally essential for many transcription factors; however, its role in ORCH and underlying mechanism(s) remain unclear and were explored here in mice with obesity induced with high-fat diet (HFD). Four week old mice were fed on either HFD (60%kcal fat) or normal diet (ND, 10% kcal fat) for 3 or 6 months, respectively. Either diet contained one of three different zinc quantities: deficiency (ZD, 10mg zinc per 4057kcal), normal (ZN, 30mg zinc per 4057kcal) or supplement (ZS, 90mg zinc per 4057kcal). HFD induced a time-dependent obesity and ORCH, which was accompanied by increased cardiac inflammation and p38 MAPK activation. These effects were worsened by ZD in HFD/ZD mice and attenuated by ZS in HFD/ZS group, respectively. Also, administration of a p38 MAPK specific inhibitor in HFD mice for 3 months did not affect HFD-induced obesity, but completely abolished HFD-induced, and zinc deficiency-worsened, ORCH and cardiac inflammation. In vitro exposure of adult cardiomyocytes to palmitate induced cell hypertrophy accompanied by increased p38 MAPK activation, which was heightened by zinc depletion with its chelator TPEN. Inhibition of p38 MAPK with its specific siRNA also prevented the effects of palmitate on cardiomyocytes. These findings demonstrate that ZS alleviates but ZD heightens cardiac hypertrophy in HFD-induced obese mice through suppressing p38 MAPK-dependent cardiac inflammatory and hypertrophic pathways.

  11. Zinc deficiency exacerbates while zinc supplement attenuates cardiac hypertrophy in high-fat diet-induced obese mice through modulating p38 MAPK-dependent signaling.

    PubMed

    Wang, Shudong; Luo, Manyu; Zhang, Zhiguo; Gu, Junlian; Chen, Jing; Payne, Kristen McClung; Tan, Yi; Wang, Yuehui; Yin, Xia; Zhang, Xiang; Liu, Gilbert C; Wintergerst, Kupper; Liu, Quan; Zheng, Yang; Cai, Lu

    2016-09-01

    Childhood obesity often leads to cardiovascular diseases, such as obesity-related cardiac hypertrophy (ORCH), in adulthood, due to chronic cardiac inflammation. Zinc is structurally and functionally essential for many transcription factors; however, its role in ORCH and underlying mechanism(s) remain unclear and were explored here in mice with obesity induced with high-fat diet (HFD). Four week old mice were fed on either HFD (60%kcal fat) or normal diet (ND, 10% kcal fat) for 3 or 6 months, respectively. Either diet contained one of three different zinc quantities: deficiency (ZD, 10mg zinc per 4057kcal), normal (ZN, 30mg zinc per 4057kcal) or supplement (ZS, 90mg zinc per 4057kcal). HFD induced a time-dependent obesity and ORCH, which was accompanied by increased cardiac inflammation and p38 MAPK activation. These effects were worsened by ZD in HFD/ZD mice and attenuated by ZS in HFD/ZS group, respectively. Also, administration of a p38 MAPK specific inhibitor in HFD mice for 3 months did not affect HFD-induced obesity, but completely abolished HFD-induced, and zinc deficiency-worsened, ORCH and cardiac inflammation. In vitro exposure of adult cardiomyocytes to palmitate induced cell hypertrophy accompanied by increased p38 MAPK activation, which was heightened by zinc depletion with its chelator TPEN. Inhibition of p38 MAPK with its specific siRNA also prevented the effects of palmitate on cardiomyocytes. These findings demonstrate that ZS alleviates but ZD heightens cardiac hypertrophy in HFD-induced obese mice through suppressing p38 MAPK-dependent cardiac inflammatory and hypertrophic pathways. PMID:27346292

  12. Endothelial lipase is upregulated by interleukin-6 partly via the p38 MAPK and p65 NF-κB signaling pathways

    PubMed Central

    Yue, Xin; Wu, Minghui; Jiang, Hong; Hao, Jing; Zhao, Qinghao; Zhu, Qing; Saren, Gaowa; Zhang, Yun; Zhang, Xiaoli

    2016-01-01

    To investigate the effects of inflammatory factor interleukin (IL)-6 on the expression of endothelial lipase (EL) and its potential signaling pathways in atherosclerosis, a primary culture of human umbilical vein endothelial cells (HUVECs) was established and treated as follows: i) Control group without any treatment; ii) recombinant human (rh)IL-6 treatment (10 ng/ml) for 0, 4, 8, 12 and 24 h; iii) p38 mitogen-activated protein kinases (MAPKs) inhibitor (SB203580, 10 µmol/l) pretreatment for 1 h prior to rhIL-6 (10 ng/ml) treatment; iv) nuclear factor (NF)-κB activation inhibitor (pyrrolidine dithiocarbamate, 10 mmol/l) pretreatment for 1 h prior to rhIL-6 (10 ng/ml) treatment. EL levels were detected by immunocytochemical staining and western blot analysis. Proliferation of HUVECs was detected by immunostaining of proliferating cell nuclear antigen (PCNA) and an MTT assay. p38 MAPK and NF-κB p65 levels were detected by western blotting. The results showed that rhIL-6 treatment increased EL expression and proliferation of HUVECs. NF-κB p65 and MAPK p38 protein levels also increased in a time-dependent manner in HUVECs after rhIL-6 treatment. NF-κB inhibitor and MAPK p38 inhibitor prevented the effects of rhIL-6 on EL expression. In conclusion, inflammatory factor IL-6 may participate in the pathogenesis of atherosclerosis by increasing EL expression and the proliferation of endothelial cells via the p38 MAPK and NF-κB signaling pathways. PMID:27430252

  13. Endothelial lipase is upregulated by interleukin-6 partly via the p38 MAPK and p65 NF-κB signaling pathways.

    PubMed

    Yue, Xin; Wu, Minghui; Jiang, Hong; Hao, Jing; Zhao, Qinghao; Zhu, Qing; Saren, Gaowa; Zhang, Yun; Zhang, Xiaoli

    2016-09-01

    To investigate the effects of inflammatory factor interleukin (IL)‑6 on the expression of endothelial lipase (EL) and its potential signaling pathways in atherosclerosis, a primary culture of human umbilical vein endothelial cells (HUVECs) was established and treated as follows: i) Control group without any treatment; ii) recombinant human (rh)IL‑6 treatment (10 ng/ml) for 0, 4, 8, 12 and 24 h; iii) p38 mitogen‑activated protein kinases (MAPKs) inhibitor (SB203580, 10 µmol/l) pretreatment for 1 h prior to rhIL‑6 (10 ng/ml) treatment; iv) nuclear factor (NF)‑κB activation inhibitor (pyrrolidine dithiocarbamate, 10 mmol/l) pretreatment for 1 h prior to rhIL‑6 (10 ng/ml) treatment. EL levels were detected by immunocytochemical staining and western blot analysis. Proliferation of HUVECs was detected by immunostaining of proliferating cell nuclear antigen (PCNA) and an MTT assay. p38 MAPK and NF‑κB p65 levels were detected by western blotting. The results showed that rhIL‑6 treatment increased EL expression and proliferation of HUVECs. NF‑κB p65 and MAPK p38 protein levels also increased in a time‑dependent manner in HUVECs after rhIL‑6 treatment. NF‑κB inhibitor and MAPK p38 inhibitor prevented the effects of rhIL‑6 on EL expression. In conclusion, inflammatory factor IL‑6 may participate in the pathogenesis of atherosclerosis by increasing EL expression and the proliferation of endothelial cells via the p38 MAPK and NF-κB signaling pathways. PMID:27430252

  14. Phosphorylation of c-Fos by members of the p38 MAPK family. Role in the AP-1 response to UV light.

    PubMed

    Tanos, Tamara; Marinissen, Maria Julia; Leskow, Federico Coluccio; Hochbaum, Daniel; Martinetto, Horacio; Gutkind, J Silvio; Coso, Omar A

    2005-05-13

    Exposure to sources of UV radiation, such as sunlight, induces a number of cellular alterations that are highly dependent on its ability to affect gene expression. Among them, the rapid activation of genes coding for two subfamilies of proto-oncoproteins, Fos and Jun, which constitute the AP-1 transcription factor, plays a key role in the subsequent regulation of expression of genes involved in DNA repair, cell proliferation, cell cycle arrest, death by apoptosis, and tissue and extracellular matrix remodeling proteases. Besides being regulated at the transcriptional level, Jun and Fos transcriptional activities are also regulated by phosphorylation as a result of the activation of intracellular signaling cascades. In this regard, the phosphorylation of c-Jun by UV-induced JNK has been readily documented, whereas a role for Fos proteins in UV-mediated responses and the identification of Fos-activating kinases has remained elusive. Here we identify p38 MAPKs as proteins that can associate with c-Fos and phosphorylate its transactivation domain both in vitro and in vivo. This phosphorylation is transduced into changes in its transcriptional ability as p38-activated c-Fos enhances AP1-driven gene expression. Our findings indicate that as a consequence of the activation of stress pathways induced by UV light, endogenous c-Fos becomes a substrate of p38 MAPKs and, for the first time, provide evidence that support a critical role for p38 MAPKs in mediating stress-induced c-Fos phosphorylation and gene transcription activation. Using a specific pharmacological inhibitor for p38alpha and -beta, we found that most likely these two isoforms mediate UV-induced c-Fos phosphorylation in vivo. Thus, these newly described pathways act concomitantly with the activation of c-Jun by JNK/MAPKs, thereby contributing to the complexity of AP1-driven gene transcription regulation.

  15. Neurite outgrowth of PC12 cells by 4'-O-β-D-glucopyranosyl-3',4-dimethoxychalcone from Brassica rapa L. 'hidabeni' was enhanced by pretreatment with p38MAPK inhibitor.

    PubMed

    Nishina, Atsuyoshi; Kimura, Hirokazu; Tsukagoshi, Hiroyuki; Kozawa, Kunihisa; Koketsu, Mamoru; Ninomiya, Masayuki; Sato, Daisuke; Obara, Yutaro; Furukawa, Shoei

    2013-11-01

    The cellular effects of eleven compounds including chalcone glycosides isolated from Brassica rapa L. 'hidabeni' and their synthetic derivatives were studied in rat pheochromocytoma PC12 cells. Of the compounds tested, 4'-O-β-D-glucopyranosyl-3',4-dimethoxychalcone (A2) significantly increased the levels of the phosphorylated forms of extracellular signal-regulated kinases 1/2 (ERK 1/2), p38 mitogen-activated protein kinase (p38MAPK), and stress-activated protein kinases/Jun amino-terminal kinases (JNK/SAPK), but it did not affect Akt. Nerve growth factor (NGF), a well-known neurotrophic factor, increased the levels of phosphorylated ERK1/2, JNK/SAPK, and Akt but not p38MAPK, which may mediate marked neurite outgrowth. Signals evoked by A2 shared common characteristics with those induced by NGF; therefore, we evaluated the neuritogenic activity of A2 and found it induced only weak neurite outgrowth. However, this effect was enhanced by pre-treatment with a p38MAPK inhibitor, suggesting that the phosphorylation of p38MAPK down-regulated neurite outgrowth. From the results of this study, it was found that A2 in combination with a p38MAPK inhibitor can induce NGF-like effects. Hence, a combination of chalcone glycosides containing A2 and a p38MAPK inhibitor increases the likelihood that chalcone glycosides could be put to practical use in the form of drugs or alternative medicines to maintain neural health.

  16. The p38α mitogen-activated protein kinase is a key regulator of myelination and remyelination in the CNS.

    PubMed

    Chung, S-H; Biswas, S; Selvaraj, V; Liu, X-B; Sohn, J; Jiang, P; Chen, C; Chmilewsky, F; Marzban, H; Horiuchi, M; Pleasure, D E; Deng, W

    2015-05-07

    The p38α mitogen-activated protein kinase (MAPK) is one of the serine/threonine kinases regulating a variety of biological processes, including cell-type specification, differentiation and migration. Previous in vitro studies using pharmacological inhibitors suggested that p38 MAPK is essential for oligodendrocyte (OL) differentiation and myelination. To investigate the specific roles of p38α MAPK in OL development and myelination in vivo, we generated p38α conditional knockout (CKO) mice under the PLP and nerve/glial antigen 2 (NG2) gene promoters, as these genes are specifically expressed in OL progenitor cells (OPCs). Our data revealed that myelin synthesis was completely inhibited in OLs differentiated from primary OPC cultures derived from the NG2 Cre-p38α CKO mouse brains. Although an in vivo myelination defect was not obvious after gross examination of these mice, electron microscopic analysis showed that the ultrastructure of myelin bundles was severely impaired. Moreover, the onset of myelination in the corpus callosum was delayed in the knockout mice compared with p38α fl/fl control mice. A delay in OL differentiation in the central nervous system was observed with concomitant downregulation in the expression of OPC- and OL-specific genes such as Olig1 and Zfp488 during early postnatal development. OPC proliferation was not affected during this time. These data indicate that p38α is a positive regulator of OL differentiation and myelination. Unexpectedly, we observed an opposite effect of p38α on remyelination in the cuprizone-induced demyelination model. The p38α CKO mice exhibited better remyelination capability compared with p38α fl/fl mice following demyelination. The opposing roles of p38α in myelination and remyelination could be due to a strong anti-inflammatory effect of p38α or a dual reciprocal regulatory action of p38α on myelin formation during development and on remyelination after demyelination.

  17. Arctigenin, a dietary phytoestrogen, induces apoptosis of estrogen receptor-negative breast cancer cells through the ROS/p38 MAPK pathway and epigenetic regulation.

    PubMed

    Hsieh, Chia-Jung; Kuo, Po-Lin; Hsu, Ying-Chan; Huang, Ya-Fang; Tsai, Eing-Mei; Hsu, Ya-Ling

    2014-02-01

    This study investigates the anticancer effect of arctigenin (ATG), a natural lignan product of Arctium lappa L., in human breast cancer MDA-MB-231 cells. Results indicate that ATG inhibits MDA-MB-231 cell growth by inducing apoptosis in vitro and in vivo. ATG triggers the mitochondrial caspase-independent pathways, as indicated by changes in Bax/Bcl-2 ratio, resulting in AIF and EndoG nuclear translocation. ATG increased cellular reactive oxygen species (ROS) production by increasing p22(phox)/NADPH oxidase 1 interaction and decreasing glutathione level. ATG clearly increases the activation of p38 MAPK, but not JNK and ERK1/2. Antioxidant EUK-8, a synthetic catalytic superoxide and hydrogen peroxide scavenger, significantly decreases ATG-mediated p38 activation and apoptosis. Blocking p38 with a specific inhibitor suppresses ATG-mediated Bcl-2 downregulation and apoptosis. Moreover, ATG activates ATF-2, a transcription factor activated by p38, and then upregulates histone H3K9 trimethylation in the Bcl-2 gene promoter region, resulting in Bcl-2 downregulation. Taken together, the results demonstrate that ATG induces apoptosis of MDA-MB-231 cells via the ROS/p38 MAPK pathway and epigenetic regulation of Bcl-2 by upregulation of histone H3K9 trimethylation.

  18. Arctigenin, a dietary phytoestrogen, induces apoptosis of estrogen receptor-negative breast cancer cells through the ROS/p38 MAPK pathway and epigenetic regulation.

    PubMed

    Hsieh, Chia-Jung; Kuo, Po-Lin; Hsu, Ying-Chan; Huang, Ya-Fang; Tsai, Eing-Mei; Hsu, Ya-Ling

    2014-02-01

    This study investigates the anticancer effect of arctigenin (ATG), a natural lignan product of Arctium lappa L., in human breast cancer MDA-MB-231 cells. Results indicate that ATG inhibits MDA-MB-231 cell growth by inducing apoptosis in vitro and in vivo. ATG triggers the mitochondrial caspase-independent pathways, as indicated by changes in Bax/Bcl-2 ratio, resulting in AIF and EndoG nuclear translocation. ATG increased cellular reactive oxygen species (ROS) production by increasing p22(phox)/NADPH oxidase 1 interaction and decreasing glutathione level. ATG clearly increases the activation of p38 MAPK, but not JNK and ERK1/2. Antioxidant EUK-8, a synthetic catalytic superoxide and hydrogen peroxide scavenger, significantly decreases ATG-mediated p38 activation and apoptosis. Blocking p38 with a specific inhibitor suppresses ATG-mediated Bcl-2 downregulation and apoptosis. Moreover, ATG activates ATF-2, a transcription factor activated by p38, and then upregulates histone H3K9 trimethylation in the Bcl-2 gene promoter region, resulting in Bcl-2 downregulation. Taken together, the results demonstrate that ATG induces apoptosis of MDA-MB-231 cells via the ROS/p38 MAPK pathway and epigenetic regulation of Bcl-2 by upregulation of histone H3K9 trimethylation. PMID:24140706

  19. Cathepsin S Activity Controls Injury-Related Vascular Repair in Mice via the TLR2-Mediated p38MAPK and PI3K−Akt/p-HDAC6 Signaling Pathway

    PubMed Central

    Wu, Hongxian; Hu, Lina; Takeshita, Kyosuke; Hu, Chen; Du, Qiuna; Li, Xiang; Zhu, Enbo; Huang, Zhe; Yisireyili, Maimaiti; Zhao, Guangxian; Piao, Limei; Inoue, Aiko; Jiang, Haiying; Lei, Yanna; Zhang, Xiaohong; Liu, Shaowen; Dai, Qiuyan; Kuzuya, Masafumi; Shi, Guo-Ping; Murohara, Toyoaki

    2016-01-01

    Objective— Cathepsin S (CatS) participates in atherogenesis through several putative mechanisms. The ability of cathepsins to modify histone tail is likely to contribute to stem cell development. Histone deacetylase 6 (HDAC6) is required in modulating the proliferation and migration of various types of cancer cells. Here, we investigated the cross talk between CatS and HADC6 in injury-related vascular repair in mice. Approach and Results— Ligation injury to the carotid artery in mice increased the CatS expression, and CatS-deficient mice showed reduced neointimal formation in injured arteries. CatS deficiency decreased the phosphorylation levels of p38 mitogen-activated protein kinase, Akt, and HDAC6 and toll-like receptor 2 expression in ligated arteries. The genetic or pharmacological inhibition of CatS also alleviated the increased phosphorylation of p38 mitogen-activated protein kinase, Akt, and HDAC6 induced by platelet-derived growth factor BB in cultured vascular smooth muscle cells (VSMCs), and p38 mitogen-activated protein kinase inhibition and Akt inhibition decreased the phospho-HDAC6 levels. Moreover, CatS inhibition caused decrease in the levels of the HDAC6 activity in VSMCs in response to platelet-derived growth factor BB. The HDAC6 inhibitor tubastatin A downregulated platelet-derived growth factor–induced VSMC proliferation and migration, whereas HDAC6 overexpression exerted the opposite effect. Tubastatin A also decreased the intimal VSMC proliferation and neointimal hyperplasia in response to injury. Toll-like receptor 2 silencing decreased the phosphorylation levels of p38 mitogen-activated protein kinase, Akt, and HDAC6 and VSMC migration and proliferation. Conclusions— This is the first report detailing cross-interaction between toll-like receptor 2–mediated CatS and HDAC6 during injury-related vascular repair. These data suggest that CatS/HDAC6 could be a potential therapeutic target for the control of vascular diseases that are

  20. TGF-β1, in association with the increased expression of connective tissue growth factor, induce the hypertrophy of the ligamentum flavum through the p38 MAPK pathway

    PubMed Central

    Cao, Yan-Lin; Duan, Yang; Zhu, Li-Xin; Zhan, Ye-Nan; Min, Shao-Xiong; Jin, An-Min

    2016-01-01

    Hypertrophy of the ligamentum flavum (LF) is one of the key pathomechanisms of lumbar spinal stenosis (LSS). Transforming growth factor (TGF)-β1 is abundantly expressed in hypertrophied degenerative LF tissues from LSS. However, the molecular mechanisms underling the association between TGF-β1 and LF hypertrophy have not yet been fully elucidated. In this study, we investigated the important role of the mitogen-activated protein kinase (MAPK) pathway in the pathogenesis of LSS by analyzing the expression of connective tissue growth factor (CTGF) and extracellular matrix (ECM) components (collagen I and collagen III) in TGF-β1-treated LF cells. Cell growth assay revealed that TGF-β1, in association with CTGF, enhanced the the proliferation of LF cells, and we found that TGF-β1 also elevated CTGF expression and subsequently enhanced the mRNA expression of collagen I and collagen III. The increased mRNA expression levels of CTGF, collagen I and collagen III were abolished by p38 inhibitors. Both immunofluorescence imaging and western blot analysis of p38 and p-p38 revealed the increased expression and phosphorylation of p38. Silencing the expression of p38 by siRNA in LF cells decreased the protein expression of p38, p-p38 and CTGF, as well as the mRNA expression of CTGF, collagen I and collagen III. Taken together, our findings indicate that TGF-β1, in association with the increased expression of CTGF, contribute to the homeostasis of the ECM and to the hypertrophy of LF through the p38 MAPK pathway. PMID:27279555

  1. Aberrant Activation of p38 MAP Kinase-Dependent Innate Immune Responses Is Toxic to Caenorhabditis elegans.

    PubMed

    Cheesman, Hilary K; Feinbaum, Rhonda L; Thekkiniath, Jose; Dowen, Robert H; Conery, Annie L; Pukkila-Worley, Read

    2016-03-01

    Inappropriate activation of innate immune responses in intestinal epithelial cells underlies the pathophysiology of inflammatory disorders of the intestine. Here we examine the physiological effects of immune hyperactivation in the intestine of the nematode Caenorhabditis elegans. We previously identified an immunostimulatory xenobiotic that protects C. elegans from bacterial infection by inducing immune effector expression via the conserved p38 MAP kinase pathway, but was toxic to nematodes developing in the absence of pathogen. To investigate a possible connection between the toxicity and immunostimulatory properties of this xenobiotic, we conducted a forward genetic screen for C. elegans mutants that are resistant to the deleterious effects of the compound, and identified five toxicity suppressors. These strains contained hypomorphic mutations in each of the known components of the p38 MAP kinase cassette (tir-1, nsy-1, sek-1, and pmk-1), demonstrating that hyperstimulation of the p38 MAPK pathway is toxic to animals. To explore mechanisms of immune pathway regulation in C. elegans, we conducted another genetic screen for dominant activators of the p38 MAPK pathway, and identified a single allele that had a gain-of-function (gf) mutation in nsy-1, the MAP kinase kinase kinase that acts upstream of p38 MAPK pmk-1. The nsy-1(gf) allele caused hyperinduction of p38 MAPK PMK-1-dependent immune effectors, had greater levels of phosphorylated p38 MAPK, and was more resistant to killing by the bacterial pathogen Pseudomonas aeruginosa compared to wild-type controls. In addition, the nsy-1(gf) mutation was toxic to developing animals. Together, these data suggest that the activity of the MAPKKK NSY-1 is tightly regulated as part of a physiological mechanism to control p38 MAPK-mediated innate immune hyperactivation, and ensure cellular homeostasis in C. elegans. PMID:26818074

  2. EP2 Induces p38 Phosphorylation via the Activation of Src in HEK 293 Cells

    PubMed Central

    Chun, Kyung-Soo; Shim, Minsub

    2015-01-01

    Prostaglandin E2 (PGE2), a major product of cyclooxygenase, binds to four different prostaglandin E2 receptors (EP1, EP2, EP3, and EP4) which are G-protein coupled transmembrane receptors (GPCRs). Although GPCRs including EP receptors have been shown to be associated with their specific G proteins, recent evidences suggest that GPCRs can regulate MAPK signaling via non-G protein coupled pathways including Src. EP2 is differentially expressed in various tissues and the expression of EP2 is induced by extracellular stimuli. We hypothesized that an increased level of EP2 expression may affect MAPK signaling. The overexpression of EP2 in HEK 293 cells resulted in significant increase in intracellular cAMP levels response to treatment with butaprost, a specific EP2 agonist, while overexpression of EP2 alone did not increase intracellular cAMP levels. However, EP2 overexpression in the absence of PGE2 induced an increase in the level of p38 phosphorylation as well as the kinase activity of p38, suggesting that up-regulation of EP2 may promote p38 activation via non-G protein coupled pathway. Inhibition of Src completely blocked EP2-induced p38 phosphorylation and overexpression of Src increased the level of p38 phosphorylation, indicating that Src is upstream kinase for EP2-induced p38 phosphorylation. EP2 overexpression also increased the Src activity and EP2 protein was co-immunoprecipitated with Src. Furthermore, sequential co-immunoprecipitation studies showed that EP2, Src, and β-arrestin can form a complex. Our study found a novel pathway in which EP2 is associated with Src, regulating p38 pathway. PMID:26535079

  3. Endoplasmic reticulum stress-induced hepatic stellate cell apoptosis through calcium-mediated JNK/P38 MAPK and Calpain/Caspase-12 pathways.

    PubMed

    Huang, Yan; Li, Xiaohui; Wang, Yarui; Wang, Huan; Huang, Cheng; Li, Jun

    2014-09-01

    Recent reports considered that it was the disturbance of calcium homeostasis and the accumulation of misfolded proteins in the endoplasmic reticulum (ER) that activated hepatic stellate cells (HSCs) apoptosis and promoted fibrosis resolution. However, the signal-transducing events that are activated by ER stress after HSCs activation were incompletely understood. In this study, we induced ER stress with thapsigargin (TG), and determined the activation of calpain and the cleavage of caspase by analyzing the protein levels and the correspondingly increased intracellular calcium levels and the induction of the proapoptotic transcription factor CHOP. Moreover, the phosphorylation of JNK and p38 MAPK were followed by the activation of the executioner caspases, caspase-3. As expected, preventing an increase in intracellular calcium levels using intracellular calcium chelators, EGTA, and BAPTA/AM, could substantially inhibit the phosphorylation of JNK and p38 MAPK, abolish the activation of calpains, namely caspase-12, caspase-9, and caspase-3, and provide significant protection for TG-treated activated HSCs. Interestingly, pretreatment with p38 MAPK inhibitor SB202190, JNK inhibitor SP600125, the pan-caspase inhibitor z-VAD-FMK, or calpain inhibitors calpeptin, significantly reduced the cell apoptosis and the cleavage of caspase-12 and caspase-3. However, pretreatment with z-VAD-FMK failed to reduce the activation of calpain. Additionally, pretreatment with SB202190 and SP600125 also decreased the expression of CHOP. Importantly, PDGF-induced collagen Col1α1 and α-smooth muscle actin (α-SMA), markers for the perpetuation phase of HSCs activation, were inhibited in TG-treated activated HSCs. These findings showed that the Calpain/Caspase-12 activation induced by ER stress and the JNK/p38 MAPK phosphorylation induced by the increase of intracellular calcium concentration releasing from ER are the novel signaling pathway underlying the molecular mechanism of fibrosis

  4. The Skp1 Homologs SKR-1/2 Are Required for the Caenorhabditis elegans SKN-1 Antioxidant/Detoxification Response Independently of p38 MAPK

    PubMed Central

    Wu, Cheng-Wei; Deonarine, Andrew; Przybysz, Aaron; Strange, Kevin; Choe, Keith P.

    2016-01-01

    SKN-1/Nrf are the primary antioxidant/detoxification response transcription factors in animals and they promote health and longevity in many contexts. SKN-1/Nrf are activated by a remarkably broad-range of natural and synthetic compounds and physiological conditions. Defining the signaling mechanisms that regulate SKN-1/Nrf activation provides insights into how cells coordinate responses to stress. Nrf2 in mammals is regulated in part by the redox sensor repressor protein named Keap1. In C. elegans, the p38 MAPK cascade in the intestine activates SKN-1 during oxidative stress by promoting its nuclear accumulation. Interestingly, we find variation in the kinetics of p38 MAPK activation and tissues with SKN-1 nuclear accumulation among different pro-oxidants that all trigger strong induction of SKN-1 target genes. Using genome-wide RNAi screening, we identify new genes that are required for activation of the core SKN-1 target gene gst-4 during exposure to the natural pro-oxidant juglone. Among 10 putative activators identified in this screen was skr-1/2, highly conserved homologs of yeast and mammalian Skp1, which function to assemble protein complexes. Silencing of skr-1/2 inhibits induction of SKN-1 dependent detoxification genes and reduces resistance to pro-oxidants without decreasing p38 MAPK activation. Global transcriptomics revealed strong correlation between genes that are regulated by SKR-1/2 and SKN-1 indicating a high degree of specificity. We also show that SKR-1/2 functions upstream of the WD40 repeat protein WDR-23, which binds to and inhibits SKN-1. Together, these results identify a novel p38 MAPK independent signaling mechanism that activates SKN-1 via SKR-1/2 and involves WDR-23. PMID:27776126

  5. Microglial activation of p38 contributes to scorpion envenomation-induced hyperalgesia.

    PubMed

    Niu, Qing-Shan; Jiang, Feng; Hua, Li-Ming; Fu, Jin; Jiao, Yun-Lu; Ji, Yong-Hua; Ding, Gang

    2013-10-25

    Intraplantar (i.pl.) injection of BmK I, a receptor site 3-specific modulator of voltage-gated sodium channels (VGSCs) from the venom of scorpion Buthus martensi Karsch (BmK), was shown to induce long-lasting and spontaneous nociceptive responses as demonstrated through experiments utilizing primary thermal and mirror-imaged mechanical hypersensitivity with different time course of development in rats. In this study, microglia was activated on both sides of L4-L5 spinal cord by i.pl. injection of BmK I. Meanwhile, the activation of p38/MAPK in L4-L5 spinal cord was found to be co-expressed with OX-42, the cell marker of microglia. The unilateral thermal and bilateral mechanical pain hypersensitivity of rat induced by BmK I was suppressed in a dose-dependent manner following pretreatment with SB203580 (a specific inhibitor of p-p38). Interestingly, microglia activity was also reduced in the presence of SB203580, which suggests that BmK I-induced microglial activation is mediated by p38/MAPK pathway. Combined with previously published literature, the results of this study demonstrate that p38-dependent microglial activation plays a role in scorpion envenomation-induced pain-related behaviors. PMID:24064352

  6. OK-432-stimulated chemokine secretion from human monocytes depends on MEK1/2, and involves p38 MAPK and NF-κB phosphorylation, in vitro.

    PubMed

    Olsnes, Carla; Bredholt, Therese; Olofsson, Jan; Aarstad, Hans J

    2013-04-01

    Interaction between the immune system and cancer cells allows for the use of biological response modifiers, like OK-432, in cancer therapy. We have studied the involvement of monocytes (MOs) in the immune response to OK-432 by examining MCP-1, MIP-1α and MIP-1β secretion, in vitro. OK-432-induced IL-6/TNF-α secretion has previously been shown to depend on mitogen-activated protein kinases (MAPKs) ERK1/2 and p38, and we therefore investigated the role of these MAPKs in OK-432-induced chemokine secretion. Here we demonstrate that pharmacological MEK1/2 kinase inhibition generally impaired chemokine secretion from MOs, whereas p38 MAPK inhibition in particular reduced MIP-1α production. Furthermore, simultaneous inhibition of MEK1/2 and Syk kinase was seen to have an additive impact on reduced MCP-1, MIP-1α and MIP-1β secretion. Based on single cell flow cytometry analyses, OK-432, lipoteichoic acid (LTA) and lipopolysaccharide (LPS) were seen to induce p38 MAPK and NF-κB phosphorylation in MOs with different time kinetics. LTA and LPS have been shown to induce ERK1/2 phosphorylation, whereas the levels of phosphorylated ERK1/2 remained constant following OK-432 treatment at the time points tested. Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns, and we demonstrate increased TLR2 cell surface levels on the MO population, most profoundly following stimulation with LTA and OK-432. Together these results indicate that modulation of MEK1/2 and p38 MAPK signalling could affect the response to OK-432 treatment, having the potential to improve its therapeutic potential within cancer and lymphangioma treatment.

  7. Sustained Oxidative Stress Causes Late Acute Renal Failure via Duplex Regulation on p38 MAPK and Akt Phosphorylation in Severely Burned Rats

    PubMed Central

    Cai, Xiaoqing; Wang, Dexin; Wu, Kaimin; Chen, Hongli; Li, Jia; Lei, Wei

    2013-01-01

    Background Clinical evidence indicates that late acute renal failure (ARF) predicts high mortality in severely burned patients but the pathophysiology of late ARF remains undefined. This study was designed to test the hypothesis that sustained reactive oxygen species (ROS) induced late ARF in a severely burned rat model and to investigate the signaling mechanisms involved. Materials and Methods Rats were exposed to 100°C bath for 15 s to induce severe burn injury (40% of total body surface area). Renal function, ROS generation, tubular necrosis and apoptosis, and phosphorylation of MAPK and Akt were measured during 72 hours after burn. Results Renal function as assessed by serum creatinine and blood urea nitrogen deteriorated significantly at 3 h after burn, alleviated at 6 h but worsened at 48 h and 72 h, indicating a late ARF was induced. Apoptotic cells and cleavage caspase-3 in the kidney went up slowly and turned into significant at 48 h and 72 h. Tubular cell ROS production shot up at 6 h and continuously rose during the 72-h experiment. Scavenging ROS with tempol markedly attenuated tubular apoptosis and renal dysfunction at 72 h after burn. Interestingly, renal p38 MAPK phosphorylation elevated in a time dependent manner whereas Akt phosphorylation increased during the first 24 h but decreased at 48 h after burn. The p38 MAPK specific inhibitor SB203580 alleviated whereas Akt inhibitor exacerbated burn-induced tubular apoptosis and renal dysfunction. Furthermore, tempol treatment exerted a duplex regulation through inhibiting p38 MAPK phosphorylation but further increasing Akt phosphorylation at 72 h postburn. Conclusions These results demonstrate that sustained renal ROS overproduction induces continuous tubular cell apoptosis and thus a late ARF at 72 h after burn in severely burned rats, which may result from ROS-mediated activation of p38 MAPK but a late inhibition of Akt phosphorylation. PMID:23349934

  8. Early activation of p38 mitogen activated protein kinase is associated with interferon-alpha-induced depression and fatigue

    PubMed Central

    Felger, Jennifer C.; Alagbe, Oyetunde; Pace, Thaddeus W. W.; Woolwine, Bobbi J.; Hu, Fang; Raison, Charles L.; Miller, Andrew H.

    2011-01-01

    Cytokine-induced stimulation of p38 mitogen activated protein kinase (MAPK) has been shown to influence behaviorally-relevant pathophysiologic pathways including monoamine neurotransmission and neuroendocrine function and thus may contribute to behavioral changes that occur during chronic administration of the innate immune cytokine, interferon (IFN)-alpha. Accordingly, in the current study, phosphorylation (activation) of intracellular p38 MAPK in peripheral blood lymphocytes was analyzed by flow cytometry every 2 hours for 12 hours following the initial injection of IFN-alpha in eleven patients with chronic hepatitis C. Hourly assessments of plasma concentrations of adrenocorticotropic hormone, cortisol and interleukin-6 were also obtained. Symptoms of depression and fatigue were measured at baseline and after 4 and 12 weeks of IFN-alpha treatment. Acute administration of IFN-alpha significantly increased the percentage of lymphocytes staining positive for intracellular phosphorylated p38 (p-p38). IFN-alpha-induced increases in p-p38 were significantly greater in patients that developed clinically significant depressive symptoms [Montgomery Asberg Depression Rating Scale (MADRS) score ≥15] during the first 12 weeks of IFN-alpha treatment. Increases in the percentage of p-p38-positive lymphocytes following the first IFN-alpha injection also highly correlated with depression severity at weeks 4 (r=0.85, p=0.001) and 12 (r=0.70, p=0.018). Similar relationships were observed for fatigue. Examination of relationships between p-p38 induction and factors previously reported to predict IFN-alpha-induced depressive symptoms revealed strong associations of p-p38 with baseline MADRS (r=0.82, p=0.002) and cortisol responses to the initial injection of IFN-alpha (r=0.91, p=0.000). Taken together, these findings indicate that sensitivity of p38 MAPK signaling pathways to immune stimulation is associated with depressive symptoms during chronic IFN-alpha treatment. PMID

  9. Activation of EGFR/ERBB2 via pathways involving ERK1/2, P38 MAPK, AKT and FOXO enhances recovery of diabetic hearts from ischemia-reperfusion injury.

    PubMed

    Akhtar, Saghir; Yousif, Mariam H M; Chandrasekhar, Bindu; Benter, Ibrahim F

    2012-01-01

    This study characterized the effects of diabetes and/or ischemia on epidermal growth factor receptor, EGFR, and/or erbB2 signaling pathways on cardiac function. Isolated heart perfusion model of global ischemia was used to study the effect of chronic inhibition or acute activation of EGFR/erbB2 signaling on cardiac function in a rat model of type-1 diabetes. Induction of diabetes with streptozotocin impaired recovery of cardiac function (cardiac contractility and hemodynamics) following 40 minutes of global ischemia in isolated hearts. Chronic treatment with AG825 or AG1478, selective inhibitors of erbB2 and EGFR respectively, did not affect hyperglycemia but led to an exacerbation whereas acute administration of the EGFR ligand, epidermal growth factor (EGF), led to an improvement in cardiac recovery in diabetic hearts. Diabetes led to attenuated dimerization and phosphorylation of cardiac erbB2 and EGFR receptors that was associated with reduced signaling via extracellular-signal-regulated kinase 1/2 (ERK1/2), p38 mitogen activated protein (MAP) kinase and AKT (protein kinase B). Ischemia was also associated with reduced cardiac signaling via these molecules whereas EGF-treatment opposed diabetes and/or ischemia induced changes in ERK1/2, p38 MAP kinase, and AKT-FOXO signaling. Losartan treatment improved cardiac function in diabetes but also impaired EGFR phosphorylation in diabetic heart. Co-administration of EGF rescued Losartan-mediated reduction in EGFR phosphorylation and significantly improved cardiac recovery more than with either agent alone. EGFR/erbB2 signaling is an important cardiac survival pathway whose activation, particularly in diabetes, ischemia or following treatment with drugs that inhibit this cascade, significantly improves cardiac function. These findings may have clinical relevance particularly in the treatment of diabetes-induced cardiac dysfunction.

  10. Oridonin induces apoptosis in SW1990 pancreatic cancer cells via p53- and caspase-dependent induction of p38 MAPK.

    PubMed

    Bu, He-Qi; Liu, Dian-Lei; Wei, Wei-Tian; Chen, Liang; Huang, Hai; Li, Ye; Cui, Jun-Hui

    2014-02-01

    Oridonin, an active component isolated from Rabdosia rubescens, has been reported to exhibit antitumor effects. In the present study, we evaluated the antitumor activity and the mechanisms of action of oridonin in pancreatic cancer. Oridonin treatment significantly induced apoptotic cell death in SW1990 pancreatic cancer cells in a dose-dependent manner. Additionally, cell apoptosis was markedly inhibited by PFT α (pifithrin α), a p53-specific inhibitor, which was applied to evaluate the function of p53, showing that p53 was responsible for the cytotoxity of oridonin. Moreover, oridonin increased the expression of p-p53 with a concomitant increase in p21 in the SW1990 cells. Following treatment with mitogen-activated protein kinase (MAPK) inhibitors, PD98059 (ERK inhibitor), SP600125 (JNK inhibitor) and SB203580 (p38 inhibitor), the cytotoxity of oridonin was not influenced by JNK (SP600125) and ERK (PD98059), but these effects were opposite to the cytotoxity of oridonin observed with SP203580 treatment. These findings confirmed that orodonin-induced apoptosis was p38-dependent, but JNK- and ERK-independent. Furthermore, the activation of the p38 kinase promoted the activation of p53 and its downstream target p21, and further caused caspase-9 and -3 activation, as demonstrated by evidence showing that the p38 inhibitor SB203580 not only blocked the phosphorylation of p38 but also reduced the activation of p53, p21 and caspase-9 and -3. Collectively, these results suggest that p53-dependent and caspase-dependent induction of p38 MAPK directly participates in apoptosis induced by oridonin. PMID:24297112

  11. p38 MAPK-dependent small HSP27 and αB-crystallin phosphorylation in regulation of myocardial function following cardioplegic arrest.

    PubMed

    Clements, Richard T; Feng, Jun; Cordeiro, Brenda; Bianchi, Cesario; Sellke, Frank W

    2011-05-01

    We previously demonstrated that myocardial p38 mitogen-activated protein kinase (MAPK) and heat shock protein 27 (HSP27) are phosphorylated following cardioplegic arrest in patients undergoing cardiac surgery and correlate with reduced cardiac function. The following studies were performed to determine whether inhibition of p38 MAPK and/or overexpression of nonphosphorylatable HSP27 improves cardiac function following cardioplegic arrest. Langendorff-perfused isolated rat hearts were subjected to 2 h of intermittent cold cardioplegia followed by 30 min of reperfusion. Hearts were treated with (CP+SB) or without (CP) the p38 MAPK inhibitor SB-203580 (5 μM) supplied in the cardioplegia. Sham-treated hearts served as controls. In separate experiments, isolated rat ventricular myocytes infected with either green fluorescent protein (GFP) or a nonphosphorylatable HSP27 mutant (3A-HSP27) were subjected to 3 h of cold hypoxic cardioplegia and simulated reperfusion (CP) followed by video microscopy and length change measurements. Baseline parameters of cardiac function were similar between groups [left ventricular developed pressure (LVDP), 119 ± 4.9 mmHg; positive and negative first derivatives of LV pressure (± dP/dt), 3,139 ± 245 and 2, 314 ± 110 mmHg/s]. CP resulted in reduced cardiac function (LVDP, 72.2 ± 5.8 mmHg; ± dP/dt, 2,076 ± 231 and -1,317 ± 156 mmHg/s) compared with baseline. Treatment with 5 μM SB-203580 significantly improved CP-induced cardiac function (LVDP, 101.9 ± 0 mmHg; ± dP/dt, 2,836 ± 163 and -2,108 ± 120 mmHg/s; P = 0.03, 0.01, and 0.04, CP+SB vs. CP). Inhibition of p38 MAPK significantly lowered CP-induced p38 MAPK, HSP27, and αB-crystallin (cryAB) phosphorylation. In vitro CP decreased myocyte length changes from 10.3 ± 1.5% (GFP) to 5.7 ± 0.8% (GFP+CP). Infection with 3A-HSP27 completely rescued CP-induced decreased myocyte contraction (11.1 ± 1.0%). However, infection with 3A-HSP27 did not block the endogenous HSP27 response

  12. Cross-talk between Smad and p38 MAPK signalling in transforming growth factor {beta} signal transduction in human glioblastoma cells

    SciTech Connect

    Dziembowska, Magdalena; Danilkiewicz, Malgorzata; Wesolowska, Aleksandra; Zupanska, Agata; Chouaib, Salem; Kaminska, Bozena . E-mail: bozenakk@nencki.gov.pl

    2007-03-23

    Transforming growth factor-beta (TGF-{beta}) is a multifunctional cytokine involved in the regulation of cell proliferation, differentiation, and survival. Malignant tumour cells often do not respond to TGF-{beta} by growth inhibition, but retain responsiveness to cytokine in regulating extracellular matrix deposition, cell adhesion, and migration. We demonstrated that TGF-{beta}1 does not affect viability or proliferation of human glioblastoma T98G, but increases transcriptional responses exemplified by induction of MMP-9 expression. TGF-{beta} receptors were functional in T98G glioblastoma cells leading to SMAD3/SMAD4 nuclear translocation and activation of SMAD-dependent promoter. In parallel, a selective activation of p38 MAPK, and phosphorylation of its substrates: ATF2 and c-Jun proteins were followed by a transient activation of AP-1 transcription factor. Surprisingly, an inhibition of p38 MAPK with a specific inhibitor, SB202190, abolished TGF-inducible activation of Smad-dependent promoter and decreased Smad2 phosphorylation. It suggests an unexpected interaction between Smad and p38 MAPK pathways in TGF-{beta}1-induced signalling.

  13. Asiaticoside attenuates the effects of spinal cord injury through antioxidant and anti‑inflammatory effects, and inhibition of the p38MAPK mechanism.

    PubMed

    Luo, Yang; Fu, Changfeng; Wang, Zhenyu; Zhang, Zhuo; Wang, Hongxia; Liu, Yi

    2015-12-01

    Asiaticoside has potent pharmacological activity and broader pharmacological effects, including anti‑oxidant, antidepressant and hepatic protection effects, and the inhibition of tumor cell proliferation. However, the mechanism underlying the effects of asiaticoside on neurological pain in spinal cord injury (SCI) remain to be fully elucidated. Therefore, the present study investigated the specific mechanism underlying the beneficial action of asiaticoside in a SCI rat model. In the present study, Basso, Beattie and Bresnahan scores was determined to analyze the therapeutic effects of asiaticoside on the neurological function of the SCI rat model. The water content of the spinal cord was also determined to measure its effects on the SCI rats. Oxidative stress, levels of nitric oxide and inflammation were detected using commercial kits. Western blot analysis was used to measure the protein expression levels of p38‑mitogen‑activated protein kinase (MAPK) in the SCI rat. Asiaticoside effectively augmented the Basso, Beattie and Bresnahan scores of the SCI rats. Significant reductions in the water content of the spinal cord, the levels of inducible nitric oxide synthase (iNOS), and the activities of the nuclear factor‑κB p65 unit, tumor necrosis factor‑α, interleukin(IL)‑1β and IL‑6 were observed in the experimental animals. Furthermore, on examination of the oxidative stress‑associated parameters, increased production of malondialdehyde and decreased levels of superoxide dismutase, glutathione and glutathione peroxidase were detected in the SCI rat model. Asiaticoside also significantly suppressed the expression of p38MAPK, which indicated that the therapeutic effects of asiaticoside may be associated with the p38MAPK pathway. These data confirmed that asiaticoside attenuates SCI through antioxidant and anti‑inflammatory effects, and through inhibition of the p38MAPK mechanism. PMID:26458544

  14. mTOR-Independent autophagy inducer trehalose rescues against insulin resistance-induced myocardial contractile anomalies: Role of p38 MAPK and Foxo1.

    PubMed

    Wang, Qiurong; Ren, Jun

    2016-09-01

    Insulin resistance is associated with cardiovascular diseases although the precise mechanisms remain elusive. Akt2, a critical member of the Akt family, plays an essential role in insulin signaling. This study was designed to examine the effect of trehalose, an mTOR-independent autophagy inducer, on myocardial function in an Akt2 knockout-induced insulin resistance model. Adult WT and Akt2 knockout (Akt2(-/-)) mice were administered trehalose (1mg/g/day, i.p.) for two days and were then given 2% trehalose in drinking water for two more months. Echocardiographic and myocardial mechanics, intracellular Ca(2+) properties, glucose tolerance, and autophagy were assessed. Apoptosis and ER stress were evaluated using TUNEL staining, Caspase 3 assay and Western blot. Autophagy and autophagy flux were examined with a focus on p38 mitogen activated protein kinase (MAPK), Forkhead box O (Foxo1) and Akt. Akt2 ablation impaired glucose tolerance, myocardial geometry and function accompanied with pronounced apoptosis, ER stress and dampened autophagy, the effects of which were ameliorated by trehalose treatment. Inhibition of lysosomal activity using bafilomycin A1 negated trehalose-induced induction of autophagy (LC3B-II and p62). Moreover, phosphorylation of p38 MAPK and Foxo1 were upregulated in Akt2(-/-) mice, the effect of which was attenuated by trehalose. Phosphorylation of Akt was suppressed in Akt2(-/-) mice and was unaffected by trehalose. In vitro findings revealed that the p38 MAPK activator anisomycin and the Foxo1 inhibitor (through phosphorylation) AS1842856 effectively masked trehalose-offered beneficial cardiomyocyte contractile response against Akt2 ablation. These data suggest that trehalose may rescue against insulin resistance-induced myocardial contractile defect and apoptosis, via autophagy associated with dephosphorylation of p38 MAPK and Foxo1 without affecting phosphorylation of Akt. PMID:27363949

  15. Asiaticoside attenuates the effects of spinal cord injury through antioxidant and anti‑inflammatory effects, and inhibition of the p38MAPK mechanism.

    PubMed

    Luo, Yang; Fu, Changfeng; Wang, Zhenyu; Zhang, Zhuo; Wang, Hongxia; Liu, Yi

    2015-12-01

    Asiaticoside has potent pharmacological activity and broader pharmacological effects, including anti‑oxidant, antidepressant and hepatic protection effects, and the inhibition of tumor cell proliferation. However, the mechanism underlying the effects of asiaticoside on neurological pain in spinal cord injury (SCI) remain to be fully elucidated. Therefore, the present study investigated the specific mechanism underlying the beneficial action of asiaticoside in a SCI rat model. In the present study, Basso, Beattie and Bresnahan scores was determined to analyze the therapeutic effects of asiaticoside on the neurological function of the SCI rat model. The water content of the spinal cord was also determined to measure its effects on the SCI rats. Oxidative stress, levels of nitric oxide and inflammation were detected using commercial kits. Western blot analysis was used to measure the protein expression levels of p38‑mitogen‑activated protein kinase (MAPK) in the SCI rat. Asiaticoside effectively augmented the Basso, Beattie and Bresnahan scores of the SCI rats. Significant reductions in the water content of the spinal cord, the levels of inducible nitric oxide synthase (iNOS), and the activities of the nuclear factor‑κB p65 unit, tumor necrosis factor‑α, interleukin(IL)‑1β and IL‑6 were observed in the experimental animals. Furthermore, on examination of the oxidative stress‑associated parameters, increased production of malondialdehyde and decreased levels of superoxide dismutase, glutathione and glutathione peroxidase were detected in the SCI rat model. Asiaticoside also significantly suppressed the expression of p38MAPK, which indicated that the therapeutic effects of asiaticoside may be associated with the p38MAPK pathway. These data confirmed that asiaticoside attenuates SCI through antioxidant and anti‑inflammatory effects, and through inhibition of the p38MAPK mechanism.

  16. Signaling by p38 MAPK stimulates nuclear localization of the microprocessor component p68 for processing of selected primary microRNAs.

    PubMed

    Hong, Sungguan; Noh, Hyangsoon; Chen, Haoming; Padia, Ravi; Pan, Zhixing K; Su, Shi-Bing; Jing, Qing; Ding, Han-Fei; Huang, Shuang

    2013-03-12

    The importance of microRNAs (miRNAs) in biological and disease processes necessitates a better understanding of the mechanisms that regulate miRNA abundance. We showed that the activities of the mitogen-activated protein kinase (MAPK) p38 and its downstream effector kinase MAPK-activated protein kinase 2 (MK2) were necessary for the efficient processing of a subset of primary miRNAs (pri-miRNAs). Through yeast two-hybrid screening, we identified p68 (also known as DDX5), a key component of the Drosha complex that processes pri-miRNAs, as an MK2-interacting protein, and we found that MK2 phosphorylated p68 at Ser(197) in cells. In wild-type mouse embryonic fibroblasts (MEFs) treated with a p38 inhibitor or in MK2-deficient (MK2(-/-)) MEFs, expression of a phosphomimetic mutant p68 fully restored pri-miRNA processing, suggesting that MK2-mediated phosphorylation of p68 was essential for this process. We found that, whereas p68 was present in the nuclei of wild-type MEFs, it was found mostly in the cytoplasm of MK2(-/-) MEFs. Nuclear localization of p68 depended on MK2-mediated phosphorylation of Ser(197). In addition, inhibition of p38 MAPK promoted the growth of wild-type MEFs and breast cancer MCF7 cells by enhancing the abundance of c-Myc through suppression of the biogenesis of the miRNA miR-145, which targets c-Myc. Because pri-miRNA processing occurs in the nucleus, our findings suggest that the p38 MAPK-MK2 signaling pathway promotes miRNA biogenesis by facilitating the nuclear localization of p68.

  17. Implication of Akt, ERK1/2 and alternative p38MAPK signalling pathways in human colon cancer cell apoptosis induced by green tea EGCG.

    PubMed

    Cerezo-Guisado, María Isabel; Zur, Rafal; Lorenzo, María Jesús; Risco, Ana; Martín-Serrano, Miguel A; Alvarez-Barrientos, Alberto; Cuenda, Ana; Centeno, Francisco

    2015-10-01

    We investigated apoptosis induced by the green tea component the epigallocatechin-3-gallate (EGCG) and the pathways underlying its activity in a colon cancer cell line. A complete understanding of the mechanism(s) and molecules targeted by green tea polyphenols could be useful in developing novel therapeutic approaches for cancer treatment. EGCG, which is the major polyphenol in green tea, has cytotoxic effects and induced cell death in HT-29 cell death. In this study, we evaluated the effect EGCG on mitogen-activated protein kinase (MAPK) and Akt pathways. EGCG treatment increased phospho-ERK1/2, -JNK1/2 and -p38α, -p38γ and -p38δ, as well as phospho-Akt levels. Using a combination of kinase inhibitors, we found that EGCG-induced cell death is partially blocked by inhibiting Akt, ERK1/2 or alternative p38MAPK activity. Our data suggest that these kinase pathways are involved in the anti-cancer effects of EGCG and indicate potential use of this compound as chemotherapeutic agent for colon cancer treatment.

  18. Dioscin alleviates BDL- and DMN-induced hepatic fibrosis via Sirt1/Nrf2-mediated inhibition of p38 MAPK pathway.

    PubMed

    Gu, Lina; Tao, Xufeng; Xu, Youwei; Han, Xu; Qi, Yan; Xu, Lina; Yin, Lianhong; Peng, Jinyong

    2016-02-01

    Oxidative stress is involved in hepatic stellate cells (HSCs) activation and extracellular matrix overproduction. We previously reported the promising effects of dioscin against CCl4-induced liver fibrosis, but its effects and mechanisms on BDL- and DMN-induced liver fibrosis remain unknown. The results in the present study indicated that dioscin significantly inhibited HSCs activation and attenuated hepatic fibrosis in rats. Furthermore, dioscin markedly up-regulated the levels of sirtuin 1 (Sirt1), HO-1, GST, GCLC and GCLM via increasing the nuclear translocation of nuclear erythroid factor 2-related factor 2 (Nrf2), which in turn inhibited mitogen-activated protein kinase 14 (p38 MAPK) phosphorylation and reduced the levels of COL1A1, COL3A1, α-SMA and fibronectin. These results were further validated by knockdown of Sirt1 and Nrf2 using siRNAs silencing, and abrogation of p38 MAPK using SB-203580 (a p38 MAPK inhibitor) in HSC-T6 and LX-2 cells. Collectively, our findings confirmed the potent effects of dioscin against liver fibrosis and also provided novel insights into the mechanisms of this compound as a candidate for the prevention of liver fibrosis in the future. PMID:26747300

  19. Isoegomaketone Upregulates Heme Oxygenase-1 in RAW264.7 Cells via ROS/p38 MAPK/Nrf2 Pathway

    PubMed Central

    Jin, Chang Hyun; So, Yang Kang; Han, Sung Nim; Kim, Jin-Baek

    2016-01-01

    Isoegomaketone (IK) was isolated from Perilla frutescens, which has been widely used as a food in Asian cuisine, and evaluated for its biological activity. We have already confirmed that IK induced the HO-1 expression via Nrf2 activation in RAW264.7 cells. In this study, we investigated the effect of IK on the mechanism of HO-1 expression. IK upregulated HO-1 mRNA and protein expression in a dose dependent manner. The level of HO-1 mRNA peaked at 4 h after 15 μM IK treatment. To investigate the mechanisms of HO-1 expression modulation by IK, we used pharmacological inhibitors for the protein kinase C (PKC) family, PI3K, and p38 MAPK. IK-induced HO-1 mRNA expression was only suppressed by SB203580, a specific inhibitor of p38 MAPK. ROS scavengers (N-acetyl-L-cysteine, NAC, and glutathione, GSH) also blocked the IK-induced ROS production and HO-1 expression. Furthermore, both NAC and SB203580 suppressed the IK-induced Nrf2 activation. In addition, ROS scavengers suppressed other oxidative enzymes such as catalase (CAT), glutathione S-transferase (GST), and NADH quinone oxidoreductase (NQO-1) in IK-treated RAW264.7 cells. Taken together, it can be concluded that IK induced the HO-1 expression through the ROS/p38 MAPK/ Nrf2 pathway in RAW264.7 cells. PMID:27582555

  20. Isoegomaketone Upregulates Heme Oxygenase-1 in RAW264.7 Cells via ROS/p38 MAPK/Nrf2 Pathway.

    PubMed

    Jin, Chang Hyun; So, Yang Kang; Han, Sung Nim; Kim, Jin-Baek

    2016-09-01

    Isoegomaketone (IK) was isolated from Perilla frutescens, which has been widely used as a food in Asian cuisine, and evaluated for its biological activity. We have already confirmed that IK induced the HO-1 expression via Nrf2 activation in RAW264.7 cells. In this study, we investigated the effect of IK on the mechanism of HO-1 expression. IK upregulated HO-1 mRNA and protein expression in a dose dependent manner. The level of HO-1 mRNA peaked at 4 h after 15 μM IK treatment. To investigate the mechanisms of HO-1 expression modulation by IK, we used pharmacological inhibitors for the protein kinase C (PKC) family, PI3K, and p38 MAPK. IK-induced HO-1 mRNA expression was only suppressed by SB203580, a specific inhibitor of p38 MAPK. ROS scavengers (N-acetyl-L-cysteine, NAC, and glutathione, GSH) also blocked the IK-induced ROS production and HO-1 expression. Furthermore, both NAC and SB203580 suppressed the IK-induced Nrf2 activation. In addition, ROS scavengers suppressed other oxidative enzymes such as catalase (CAT), glutathione S-transferase (GST), and NADH quinone oxidoreductase (NQO-1) in IK-treated RAW264.7 cells. Taken together, it can be concluded that IK induced the HO-1 expression through the ROS/p38 MAPK/ Nrf2 pathway in RAW264.7 cells. PMID:27582555

  1. Antimelanogenic effect of c-phycocyanin through modulation of tyrosinase expression by upregulation of ERK and downregulation of p38 MAPK signaling pathways

    PubMed Central

    2011-01-01

    Background Pigmentation is one of the essential defense mechanisms against oxidative stress or UV irradiation; however, abnormal hyperpigmentation in human skin may pose a serious aesthetic problem. C-phycocyanin (Cpc) is a phycobiliprotein from spirulina and functions as an antioxidant and a light harvesting protein. Though it is known that spirulina has been used to reduce hyperpigmentation, little literature addresses the antimelanogenic mechanism of Cpc. Herein, we investigated the rationale for the Cpc-induced inhibitory mechanism on melanin synthesis in B16F10 melanoma cells. Methods Cpc-induced inhibitory effects on melanin synthesis and tyrosinase expression were evaluated. The activity of MAPK pathways-associated molecules such as MAPK/ERK and p38 MAPK, were also examined to explore Cpc-induced antimelanogenic mechanisms. Additionally, the intracellular localization of Cpc was investigated by confocal microscopic analysis to observe the migration of Cpc. Results Cpc significantly (P < 0.05) reduced both tyrosinase activity and melanin production in a dose-dependent manner. This phycobiliprotein elevated the abundance of intracellular cAMP leading to the promotion of downstream ERK1/2 phosphorylation and the subsequent MITF (the transcription factor of tyrosinase) degradation. Further, Cpc also suppressed the activation of p38 causing the consequent disturbed activation of CREB (the transcription factor of MITF). As a result, Cpc negatively regulated tyrosinase gene expression resulting in the suppression of melanin synthesis. Moreover, the entry of Cpc into B16F10 cells was revealed by confocal immunofluorescence localization and immunoblot analysis. Conclusions Cpc exerted dual antimelanogenic mechanisms by upregulation of MAPK/ERK-dependent degradation of MITF and downregulation of p38 MAPK-regulated CREB activation to modulate melanin formation. Cpc may have potential applications in biomedicine, food, and cosmetic industries. PMID:21988805

  2. Docosahexenoic acid treatment ameliorates cartilage degeneration via a p38 MAPK-dependent mechanism

    PubMed Central

    WANG, ZHENZHONG; GUO, AI; MA, LIFENG; YU, HAOMIAO; ZHANG, LIANG; MENG, HAI; CUI, YINPENG; YU, FEI; YANG, BO

    2016-01-01

    Osteoarthritis (OA) is a common chronic inflammatory disease, characterized by cartilage degradation. The aberrant expression of matrix metalloproteinase-13 (MMP-13) plays a vital role in the pathogenesis of OA. The anti-inflammatory property of docosahexenoic acid (DHA) was previously revealed and showed that DHA retards the progress of many types of inflammatory disease. To evaluate the prophylactic function of DHA in OA, the effect of DHA on cartilage degeneration was assessed in interleukin-1β (IL-1β) stimulated human chondrosarcoma SW1353 cells or a rat model of adjuvant-induced arthritis (AIA). The safe concentration range (0–50 µg/ml in vitro) of DHA was determined by flow cytometry and MTT assay. The inhibitory effects of DHA on MMP-13 mRNA and protein expression were confirmed by RT-qPCR, ELISA and western blotting. Furthermore, findings of an in vivo study showed that DHA can increase the thickness of articular cartilage and decrease MMP-13 expression in cartilage matrix in a rat AIA model. We also revealed the mechanism by which DHA ameliorates cartilage degeneration from OA. The DHA-mediated inhibition of MMP-13 expression was partially attributed to the inactivation of the p38 mitogen-activated protein kinases pathway by suppressing p-p38 in IL-1β-stimulated SW1353 cells and a rat AIA model. Our findings suggested that DHA is a promising therapeutic agent that may be used for the prevention and treatment of OA. PMID:27082436

  3. Mitochondrial DNA is released by shock and activates neutrophils via p38 map kinase.

    PubMed

    Zhang, Qin; Itagaki, Kiyoshi; Hauser, Carl J

    2010-07-01

    Bacterial DNA (bDNA) can activate an innate-immune stimulatory "danger" response via toll-like receptor 9 (TLR9). Mitochondrial DNA (mtDNA) is unique among endogenous molecules in that mitochondria evolved from prokaryotic ancestors. Thus, mtDNA retains molecular motifs similar to bDNA. It is unknown, however, whether mtDNA is released by shock or is capable of eliciting immune responses like bDNA. We hypothesized shock-injured tissues might release mtDNA and that mtDNA might act as a danger-associated molecular pattern (or "alarmin") that can activate neutrophils (PMNs) and contribute to systemic inflammatory response syndrome. Standardized trauma/hemorrhagic shock caused circulation of mtDNA as well as nuclear DNA. Human PMNs were incubated in vitro with purified mtDNA or nuclear DNA, with or without pretreatment by chloroquine (an inhibitor of endosomal receptors like TLR9). Neutrophil activation was assessed as matrix metalloproteinase (MMP) 8 and MMP-9 release as well as p38 and p44/42 mitogen-activated protein kinase (MAPK) phosphorylation. Mitochondrial DNA induced PMN MMP-8/MMP-9 release and p38 phosphorylation but did not activate p44/42. Responses were inhibited by chloroquine. Nuclear DNA did not induce PMN activation. Intravenous injection of disrupted mitochondria (mitochondrial debris) into rats induced p38 MAPK activation and IL-6 and TNF-alpha accumulation in the liver. In summary, mtDNA is released into the circulation by shock. Mitochondrial DNA activates PMN p38 MAPK, probably via TLR9, inducing an inflammatory phenotype. Mitochondrial DNA may act as a danger-associated molecular pattern or alarmin after shock, contributing to the initiation of systemic inflammatory response syndrome.

  4. Opposite Roles for p38MAPK-Driven Responses and Reactive Oxygen Species in the Persistence and Resolution of Radiation-Induced Genomic Instability

    PubMed Central

    Werner, Erica; Wang, Huichen; Doetsch, Paul W.

    2014-01-01

    We report the functional and temporal relationship between cellular phenotypes such as oxidative stress, p38MAPK-dependent responses and genomic instability persisting in the progeny of cells exposed to sparsely ionizing low-Linear Energy Transfer (LET) radiation such as X-rays or high-charge and high-energy (HZE) particle high-LET radiation such as 56Fe ions. We found that exposure to low and high-LET radiation increased reactive oxygen species (ROS) levels as a threshold-like response induced independently of radiation quality and dose. This response was sustained for two weeks, which is the period of time when genomic instability is evidenced by increased micronucleus formation frequency and DNA damage associated foci. Indicators for another persisting response sharing phenotypes with stress-induced senescence, including beta galactosidase induction, increased nuclear size, p38MAPK activation and IL-8 production, were induced in the absence of cell proliferation arrest during the first, but not the second week following exposure to high-LET radiation. This response was driven by a p38MAPK-dependent mechanism and was affected by radiation quality and dose. This stress response and elevation of ROS affected genomic instability by distinct pathways. Through interference with p38MAPK activity, we show that radiation-induced stress phenotypes promote genomic instability. In contrast, exposure to physiologically relevant doses of hydrogen peroxide or increasing endogenous ROS levels with a catalase inhibitor reduced the level of genomic instability. Our results implicate persistently elevated ROS following exposure to radiation as a factor contributing to genome stabilization. PMID:25271419

  5. Induction of COX-2 protein expression by vanadate in A549 human lung carcinoma cell line through EGF receptor and p38 MAPK-mediated pathway

    SciTech Connect

    Chien, P.-S.; Mak, O.-T.; Huang, H.-J. . E-mail: haojen@mail.ncku.edu.tw

    2006-01-13

    Vanadate is a transition metal widely distributed in the environment. It has been reported that vanadate associated with air pollution particles can modify DNA synthesis, causing cell growth arrest, and apoptosis. Moreover, vanadium exposure was also found to cause the synthesis of inflammatory cytokines, such as interleukin-1, tumor necrosis factor-{alpha}, and prostaglandin E{sub 2}. Here, we found that exposure of A549 human lung carcinoma cells to vanadate led to extracellular signal-regulated kinase, c-Jun NH{sub 2}-terminal protein kinases (JNKs), p38 mitogen-activated protein kinase (p38) activation, and COX-2 protein expression in a dose-dependent manner. SB203580, a p38 MAPK inhibitor, but not PD098059 and SP600125, specific inhibitor of MKK1 and selective inhibitor of JNK, respectively, suppressed COX-2 expression. Furthermore, the epithelial growth factor (EGF) receptor specific inhibitor (PD153035) reduced vanadate-induced COX-2 expression. However, scavenging of vanadate-induced reactive oxygen species by catalase, a specific H{sub 2}O{sub 2} inhibitor, or DPI, an NADPH oxidase inhibitor, resulted in no inhibition on COX-2 expression. Together, we suggested that EGF receptor and p38 MAPK signaling pathway may be involved in vanadate-induced COX-2 protein expression in A549 human lung carcinoma cell line.

  6. SIRT1 protects rat lung tissue against severe burn-induced remote ALI by attenuating the apoptosis of PMVECs via p38 MAPK signaling

    PubMed Central

    Bai, Xiaozhi; Fan, Lei; He, Ting; Jia, Wenbin; Yang, Longlong; Zhang, Jun; Liu, Yang; Shi, Jihong; Su, Linlin; Hu, Dahai

    2015-01-01

    Silent information regulator type-1 (SIRT1) has been reported to be involved in the cardiopulmonary protection. However, its role in the pathogenesis of burn-induced remote acute lung injury (ALI) is currently unknown. The present study aims to investigate the role of SIRT1 in burn-induced remote ALI and the involved signaling pathway. We observed that SIRT1 expression in rat lung tissue after burn injury appeared an increasing trend after a short period of suppression. The upregulation of SIRT1 stimulated by resveratrol exhibited remission of histopathologic changes, reduction of cell apoptosis, and downregulation of pro-inflammatory cytokines in rat pulmonary tissues suffering from severe burn. We next used primary pulmonary microvascular endothelial cells (PMVECs) challenged by burn serum (BS) to simulate in vivo rat lung tissue after burn injury, and found that BS significantly suppressed SIRT1 expression, increased cell apoptosis, and activated p38 MAPK signaling. The use of resveratrol reversed these effects, while knockdown of SIRT1 by shRNA further augmented BS-induced increase of cell apoptosis and activation of p38 MAPK. Taken together, these results indicate that SIRT1 might protect lung tissue against burn-induced remote ALI by attenuating PMVEC apoptosis via p38 MAPK signaling, suggesting its potential therapeutic effects on the treatment of ALI. PMID:25992481

  7. 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.

  8. 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. PMID:26503828

  9. 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

  10. PKD prevents H{sub 2}O{sub 2}-induced apoptosis via NF-{kappa}B and p38 MAPK in RIE-1 cells

    SciTech Connect

    Song Jun; Li Jing; Qiao Jingbo; Jain, Sunil; Mark Evers, B.; Chung, Dai H.

    2009-01-16

    Previously, we demonstrated that protein kinase D (PKD) plays a protective role during H{sub 2}O{sub 2}-induced intestinal cell death. Here, we sought to determine whether this effect is mediated by nuclear factor-{kappa}B (NF-{kappa}B) and mitogen-activated protein kinases (MAPKs). Treatment with H{sub 2}O{sub 2} activated NF-{kappa}B in RIE-1 cells; H{sub 2}O{sub 2} also induced the translocation of NF-{kappa}B p65 as well as phosphorylation of I{kappa}B-{alpha}. PKD1 siRNA inhibited H{sub 2}O{sub 2}-induced activation, translocation of NF-{kappa}B, and phosphorylation of I{kappa}B-{alpha}. We also found that overexpression of wild type PKD1 attenuated H{sub 2}O{sub 2}-induced phosphorylation of p38 MAPK and its upstream activator, MAPK kinase (MKK) 3/6, whereas the phosphorylation was increased by PKD1 siRNA or kinase-dead PKD1. Phosphorylation of neither extracellular signal-regulated kinases (ERK) 1/2 nor c-Jun N-terminal kinases (JNK) was altered by PKD1 plasmids or siRNA. Our findings suggest that PKD protects intestinal cells through up-regulation of NF-{kappa}B and down-regulation of p38 MAPK.

  11. Baicalin ameliorates isoproterenol-induced acute myocardial infarction through iNOS, inflammation, oxidative stress and P38MAPK pathway in rat

    PubMed Central

    Sun, Shen-Jie; Wu, Xiao-Peng; Song, Heng-Liang; Li, Gui-Qi

    2015-01-01

    Baicalin is one of the active ingredients in the skullcap, with a variety of pharmacological effects, such as blood pressure reduction, sedation, liver-protection, gallbladder-protection, anti-bacteria, anti-inflammation, etc. The aim of this study was to investigate the potential cardioprotective effects of baicalin ameliorates isoproterenol-induced acute myocardial infarction (AMI) through inducible nitric oxide synthase (iNOS), inflammation, oxidative stress and P38MAPK passageway in rat. Rat model of AMI was induced by isoproterenol (100 mg/kg) and then treated baicalin (various does of baicalin: 1 mg/kg, 10 mg/kg and 100 mg/kg, respectively) for 24 h. Infarct size, the heart weight to body weight ratio and creatine kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) of rats with AMI induced by isoproterenol were used to evaluate curative effect of baicalin on AMI. Meanwhile, iNOS and phosphorylation-p38 MAPK (p-p38) protein expressions, inflammatory factor and oxidative stress were inspected using western blot and commercial kits, respectively. In the present study, pre-treatment with baicalin (10 or 100 mg/kg) significantly ameliorated infarct size, the heart weight to body weight ratio and CK, CK-MB, LDH and cTnT levels in rats with AMI induced by isoproterenol. iNOS protein expression, the serum TNF-α, IL-6, MDA and SOD levels and p-38 protein expressions were significantly suppressed by treatment with baicalin (10 or 100 mg/kg). These results suggest that acute treatment with baicalin ameliorates AMI, iNOS, inflammation, oxidative stress and P38MAPK pathway in rat with AMI induced by isoproterenol. PMID:26885181

  12. Paris saponin VII suppresses osteosarcoma cell migration and invasion by inhibiting MMP-2/9 production via the p38 MAPK signaling pathway

    PubMed Central

    Cheng, Gong; Gao, Fengguang; Sun, Xiujiang; Bi, Haiyong; Zhu, Yonglin

    2016-01-01

    Metastasis is the primary cause of mortality in osteosarcoma. Targeting metastasis is a major strategy in osteosarcoma treatment. As a traditional Chinese medicine, Trillium tschonoskii Maxim has been widely used in the therapy of various diseases, including cancer. However, currently there is no evidence regarding the anti-metastasic effect of Paris saponin VII (PS VII), which is extracted from Trillium tschonoskii Maxim, on osteosarcoma cells and its underling mechanisms. The present study aimed to examine the effect of PS VII on the migration and invasion of osteosarcoma cells. Viability and proliferation of osteosarcoma cells were examined by MTT assay. Migration and invasion of osteosarcoma cells was then detected using scratch wound healing assays and Transwell assays, respectively. Additionally, the expression of matrix metalloproteinase (MMP)-2 and -9 was determined at the mRNA and protein level following treatment with PS VII. Mitogen-activated protein kinase (MAPK) expression was also detected by western blot analysis. Finally, an inhibitor of p38 MAPK was used to verify the effect of PS VII on the expression of MMP-2 and -9, as well as the migration and invasion osteosarcoma cells. This demonstrated that the proliferation, migration and invasion of the osteosarcoma cells were suppressed following treatment with PS VII. PS VII downregulated the expression of MMP-2 and -9 in a dose- and time-dependent manner. PS VII also exerted its ability to downregulate the phosphorylation of p38 MAPKs. Furthermore, by using a p38 inhibitor, SB203580, the role of PS VII in MMP-2 and -9 expression and osteosarcoma cell invasion was revealed. Taken together, these results demonstrated that PS VII suppresses the migration and invasion of osteosarcoma cells via the p38 MAPK signaling pathway. PMID:27572907

  13. Glutamine supplementation prevents exercise-induced neutrophil apoptosis and reduces p38 MAPK and JNK phosphorylation and p53 and caspase 3 expression.

    PubMed

    Lagranha, Claudia J; Hirabara, Sandro M; Curi, Rui; Pithon-Curi, Tania C

    2007-01-01

    We have previously shown that a single session of exercise induces DNA fragmentation, mitochondrial membrane depolarization, increases expression of pro-apoptotic genes (bax and bcl-xS) and decreases expression of anti-apoptotic genes (bcl-xL) in rat neutrophils. Glutamine supplementation had a protective effect in the apoptosis induced by a single session of exercise. The mechanism involved in the effect of single session of exercise to induce apoptosis was investigated by measuring expression of p53 and caspase 3 and phosphorylation of p38 mitogen-activated protein kinases (MAPK) and cJun NH(2)-terminal kinase (JNK) in neutrophils from rats supplemented or not with glutamine. Exercise was carried out on a treadmill for 1 h and the rats were killed by decapitation. Neutrophils were obtained by intraperitoneal (i.p.) lavage with PBS, 4 h after injection of oyster glycogen solution. Glutamine supplementation (1g per Kg b.w.) was given by gavage 1 h before the exercise session. Gene expression and protein phosphorylation were then analyzed by reverse transcriptase chain reaction (RT-PCR) and Western blotting, respectively. A single session of exercise increased p38 MAPK and JNK phosphorylation and p53 and caspase 3 expression. Glutamine supplementation partially prevented the increase in p38 MAPK and JNK phosphorylation and p53 expression, and fully abolished the increase in caspase 3 expression. Thus, neutrophil apoptosis induced by a single session of exercise is accompanied by increased p53 and caspase 3 expression and p38 MAPK and JNK phosphorylation. Glutamine supplementation prevents these effects of exercise and reduces apoptosis. PMID:17542038

  14. Glutamine supplementation prevents exercise-induced neutrophil apoptosis and reduces p38 MAPK and JNK phosphorylation and p53 and caspase 3 expression.

    PubMed

    Lagranha, Claudia J; Hirabara, Sandro M; Curi, Rui; Pithon-Curi, Tania C

    2007-01-01

    We have previously shown that a single session of exercise induces DNA fragmentation, mitochondrial membrane depolarization, increases expression of pro-apoptotic genes (bax and bcl-xS) and decreases expression of anti-apoptotic genes (bcl-xL) in rat neutrophils. Glutamine supplementation had a protective effect in the apoptosis induced by a single session of exercise. The mechanism involved in the effect of single session of exercise to induce apoptosis was investigated by measuring expression of p53 and caspase 3 and phosphorylation of p38 mitogen-activated protein kinases (MAPK) and cJun NH(2)-terminal kinase (JNK) in neutrophils from rats supplemented or not with glutamine. Exercise was carried out on a treadmill for 1 h and the rats were killed by decapitation. Neutrophils were obtained by intraperitoneal (i.p.) lavage with PBS, 4 h after injection of oyster glycogen solution. Glutamine supplementation (1g per Kg b.w.) was given by gavage 1 h before the exercise session. Gene expression and protein phosphorylation were then analyzed by reverse transcriptase chain reaction (RT-PCR) and Western blotting, respectively. A single session of exercise increased p38 MAPK and JNK phosphorylation and p53 and caspase 3 expression. Glutamine supplementation partially prevented the increase in p38 MAPK and JNK phosphorylation and p53 expression, and fully abolished the increase in caspase 3 expression. Thus, neutrophil apoptosis induced by a single session of exercise is accompanied by increased p53 and caspase 3 expression and p38 MAPK and JNK phosphorylation. Glutamine supplementation prevents these effects of exercise and reduces apoptosis.

  15. The intrathecal administration of losartan, an AT1 receptor antagonist, produces an antinociceptive effect through the inhibiton of p38 MAPK phosphorylation in the mouse formalin test.

    PubMed

    Nemoto, Wataru; Ogata, Yoshiki; Nakagawasai, Osamu; Yaoita, Fukie; Tanado, Takeshi; Tan-No, Koichi

    2015-01-12

    We have recently reported that an intrathecal (i.t.) administration of angiotensin II (Ang II) into mice induces a nociceptive behavior accompanied by the activation of p38 MAPK signaling via AT1 receptors (Nemoto et al., 2013, Mol. Pain 9, 38). These results suggested that Ang II participates in the facilitation of nociceptive transmission in the spinal cord. In the present study, we used formalin test to examine the effect of i.t.-administered losartan, an AT1 receptor antagonist, and determine whether Ang II acts as a neurotransmitter and/or neuromodulator in the spinal transmission of nociceptive information. When administered i.t. 5 min before the injection of a 2% formalin solution into the plantar surface of the hindpaw, losartan (30-100 nmol) produced a dose-dependent and significant antinociceptive effect during both the first and second phases of the test. In the superficial dorsal horn of the spinal cord (laminae I and II), the fluorescence intensities for Ang II and phospho-p38 MAPK were both significantly increased on the ipsilateral side 3 min after the injection of formalin compared to saline-treated controls. Moreover, the increase of phospho-p38 MAPK fluorescence intensity was significantly inhibited by the i.t. administration of losartan (54.8 nmol) 5 min prior to formalin. These results indicate that losartan produces an antinociceptive effect through the inhibition of p38 MAPK phosphorylation in the mouse formalin test and that Ang II may act as a neurotransmitter and/or neuromodulator in the spinal transmission of nociceptive information.

  16. Neurite Outgrowth in PC12 Cells Stimulated by Components from Dendranthema × grandiflorum cv. “Mottenohoka” Is Enhanced by Suppressing Phosphorylation of p38MAPK

    PubMed Central

    Kimura, Hirokazu; Tsukagoshi, Hiroyuki; Kozawa, Kunihisa; Koketsu, Mamoru; Ninomiya, Masayuki; Furukawa, Shoei

    2013-01-01

    Components from Dendranthema × grandiflorum cv. “Mottenohoka” that promote neurite outgrowth of PC12 cells were identified and the mechanism of neurite outgrowth stimulated by isolated components was studied. Components that promoted the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK 1/2) of PC12 cells were isolated. From various structural analyses, the active components were identified as acacetin and luteolin. The effects of acacetin or luteolin on PC12 cells were evaluated by electro-blotting and immunostaining. Slight neurite outgrowth in PC12 cells was observed within 2 days of culture after stimulation by luteolin or acacetin. However, NGF-stimulation induced remarkable neurite outgrowth in comparison. Neurite outgrowth by luteolin or acacetin was significantly enhanced by pretreatment with SB203580 (a p38MAPK inhibitor). The results of this study into the phosphorylation of ERK 1/2 and p38MAPK by flavonoids suggest that the inhibition of p38MAPK phosphorylation may effectively enhance neurite outgrowth. PMID:23554829

  17. Butein sensitizes HeLa cells to cisplatin through the AKT and ERK/p38 MAPK pathways by targeting FoxO3a

    PubMed Central

    ZHANG, LIRUI; YANG, XIAOFENG; LI, XU; LI, CHEN; ZHAO, LE; ZHOU, YUANYUAN; HOU, HUILIAN

    2015-01-01

    Drug resistance remains a major challenge in cancer therapy. Butein, a polyphenolic compound, has been shown to exhibit anticancer activity through the inhibition of the activation of the protein kinase B (PKB/AKT) and mitogen-activated protein kinase (MAPK) pathways, which are two pathways known to be involved in resistance to cisplatin. Hence, we hypotheiszed that butein may be a chemosensitizer to cisplatin. In the present study, we demonstrated that butein synergistically enhanced the growth inhibitory and apoptosis-inducing effects of cisplatin on HeLa cells. Moreover, the combination of butein and cisplatin led to G1 phase arrest. We then aimed to explore the underlying mechanisms. We found that butein inhibited the activation of AKT, extracellular signal-regulated kinase (ERKs) and p38 kinases in the presence of cisplatin. The use of the AKT inhibitor, LY294002, in combination with cisplatin, induced an increase in apoptosis compared to treatment with cisplatin alone, although this effect was not as prominent as that exerted by butein in combination with cisplatin. Of note, the inhibition of ERK or p38 MAPK by U0126 or SB203580, respectively, decreased the apoptosis induced by cisplatin; however, enhanced apoptotic effects were observed with the use of ERK/p38 MAPK inhibitor in combination with butein. These data suggest that the AKT and ERK/p38 MAPK pathways are involved in the synergistic effects of butein and cisplatin. Furthermore, co-treatment with butein and cisplatin promoted the nuclear translocation and expression of forkhead box O3a (FoxO3 or FoxO3a). FoxO3a may be the key molecule on which these pathways converge and is thus implicated in the synergistic effects of butein and cisplatin. This was further confirmed by the RNAi-mediated suppression of FoxO3a. FoxO3a target genes involved in cell cycle progression and apoptosis were also investigated, and combined treatment with butein and cisplatin resulted in the downregulation of cyclin D1 and Bcl

  18. Role of p38 Mitogen-Activated Protein Kinase in Middle Ear Mucosa Hyperplasia during Bacterial Otitis Media

    PubMed Central

    Palacios, Sean D.; Pak, Kwang; Rivkin, Alexander Z.; Kayali, Ayse G.; Austen, Darrell; Aletsee, Christoph; Melhus, Åsa; Webster, Nicholas J. G.; Ryan, Allen F.

    2004-01-01

    Hyperplasia of the middle ear mucosa contributes to the sequelae of acute otitis media. Understanding the signal transduction pathways that mediate hyperplasia could lead to the development of new therapeutic interventions for this disease and its sequelae. Endotoxin derived from bacteria involved in middle ear infection can contribute to the hyperplastic response. The p38 mitogen-activated protein kinase (MAPK) is known to be activated by endotoxin as well as cytokines and other inflammatory mediators that have been documented in otitis media. We assessed the activation of p38 in the middle ear mucosa of an in vivo rat bacterial otitis media model. Strong activity of p38 was observed 1 to 6 h after bacterial inoculation. Activity continued at a lower level for at least 7 days. The effects of p38 activation were assessed using an in vitro model of rat middle ear mucosal hyperplasia in which mucosal growth is stimulated by nontypeable Haemophilus influenzae during acute otitis media. Hyperplastic mucosal explants treated with the p38α and p38β inhibitor SB203580 demonstrated significant inhibition of otitis media-stimulated mucosal growth. The results of this study suggest that intracellular signaling via p38 MAPK influences the hyperplastic response of the middle ear mucosa during bacterial otitis media. PMID:15271927

  19. p38α MAPK mediates 17β-estradiol inhibition of MMP-2 and -9 expression and cell migration in human lovo colon cancer cells.

    PubMed

    Hsu, Hsi-Hsien; Liu, Chung-Jung; Shen, Chia-Yao; Chen, Yi-Jyun; Chen, Li-Mien; Kuo, Wu-Hsien; Lin, Yueh-Min; Chen, Ray-Jade; Tsai, Chang-Hai; Tsai, Fuu-Jen; Huang, Chih-Yang

    2012-11-01

    Epidemiological studies demonstrate that the incidence and mortality rates of colorectal cancer in women are lower than in men. However, it is unknown if 17β-estradiol (E(2)) treatment is sufficient to inhibit cell proliferation and cell migration in human colon cancer cells. Up-regulation of urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA), and matrix metallopeptidases (MMPs) is reported to associate with the development of cancer cell mobility, metastasis, and subsequent malignant tumor. In the present study, we treated human LoVo colon cancer cells with E(2) to explore whether E(2) down-regulates cell proliferation and migration, and to identify the precise molecular and cellular mechanisms behind the down-regulatory responses. Here, we found that E(2) treatment decreased cell proliferation and cell cycle-regulating factors such as cyclin A, cyclin D1 and cyclin E. At the same time, E(2) significantly inhibited cell migration and migration-related factors such as uPA, tPA, MMP-2, and MMP-9. However, E(2) treatment showed no effects on upregulating expression of plasminogen activator inhibitor-1 (PAI-1), tissue inhibitor of metalloproteinase-1, -2, -3, and -4 (TIMP-1, -2, -3, and -4). After administration of inhibitors including QNZ (NFκB inhibitor), LY294002 (Akt activation inhibitor), U0126 (ERK1/2 inhibitor), SB203580 (p38 MAPK inhibitor) or SP600125 (JNK1/2 inhibitor), E(2) -downregulated cell migration and expression of MMP-2 and MMP-9 in LoVo cells is markedly inhibited only by p38 MAPK inhibitors, SB203580. Application of specific target gene siRNA (ERα, ERβ, p38α, and p38β) to LoVo cells further confirmed that p38 MAPK mediates E(2) /ERs inhibition of MMP-2 and -9 expression and cell motility in LoVo cells. Collectively, these results suggest that E(2) treatment down-regulates cell proliferation by modulating the expression of cyclin A, cyclin D1 and cyclin E. E(2) treatment simultaneously impaired cell migration by

  20. BMP4 Increases the Expression of TRPC and Basal [Ca2+]i via the p38MAPK and ERK1/2 Pathways Independent of BMPRII in PASMCs

    PubMed Central

    Tian, Lichun; Fu, Xin; Wang, Yan; Sun, Yueqian; Jiang, Qian; Lu, Wenju; Wang, Jian

    2014-01-01

    Multiple abnormalities of bone morphogenetic protein (BMPs) signaling are implicated in the process of pulmonary arterial hypertension (PAH). BMP4 plays an important role during the process of pulmonary arterial remodeling and mutant of the principle BMP4 receptor, BMP receptors II (BMPRII), is found to associate with the development of PAH. However, the likely mechanism defining the contribution of BMPRII to BMP4 mediated signaling in pulmonary arterial smooth muscle cells (PASMCs) remains comprehensively unclear. We previously found that enhanced store operated calcium entry (SOCE) and basal intracellular calcium concentration [Ca2+]i were induced by BMP4 via upregulation of TRPC1, 4 and 6 expression in PASMCs, and that BMP4 modulated TRPC channel expression through activating p38MAPK and ERK1/2 signaling pathways. In this study, BMPRII siRNA was used to knockdown BMPRII expression to investigate whether BMP4 upregulates the expression of TRPC and activating Smad1/5/8, ERK1/2 and p38MAPK pathway via BMPRII in distal PASMCs. Our results showed that knockdown of BMPRII: 1) attenuated BMP4 induced activation of P-Smad1/5/8, without altering BMP4 induced P-p38MAPK and P-ERK1/2 activation in PASMCs; 2) did not attenuate the BMP4-induced TRPC1, 4 and 6 expression; 3) did not affect BMP4-enhanced SOCE and basal [Ca2+]i. Thus, we concluded that BMP4 activated Smad1/5/8 pathway is BMPRII-dependent, while the BMP4 – ERK/p-P38 – TRPC – SOCE signaling axis are likely mediated through other receptor rather than BMPRII. PMID:25461595

  1. Nicotine enhances invasion and metastasis of human colorectal cancer cells through the nicotinic acetylcholine receptor downstream p38 MAPK signaling pathway.

    PubMed

    Xiang, Tao; Fei, Rushan; Wang, Zhe; Shen, Zhonglei; Qian, Jing; Chen, Wenbin

    2016-01-01

    Nicotine as a cigarette component is an established risk factor for colorectal cancer tumorigenesis. The downstream signaling pathways of nicotinic acetylcholine receptors (nAchRs) are believed to be responsible for the cellular effects. In the present study, we evaluated the effects and novel mechanisms for nicotine on the capacity for colorectal cancer cell invasion and metastasis. LOVO and SW620 colorectal cancer cells were stimulated with nicotine in vitro. A Transwell chamber model was applied to detect the capacity for tumor cell invasion. Assays for gelatin zymography and western blotting were applied to detect the activity and expression of metastasis-related matrix metalloproteinases (MMPs), respectively. Signal transduction was assessed by immunoblotting for the phosphorylation of relevant signal molecules and the application of pharmaceutical inhibitors. We showed that nicotine increased LOVO and SW620 colorectal cancer cell invasion along with enhanced activity and expression of MMP-1, -2 and -9. Nicotine increased phosphorylation of p38, ERK, Akt and PI3K p85 but had no effect on phosphorylation of JNK, or NF-κB. Of the pharmaceutical inhibitors of U0126 (ERK1/2 inhibitor), LY294002 (Akt activation inhibitor), SB239063 (p38 MAPK activation inhibitor) and hexamethonium (Hex) (nAchRs inhibitor), the cellular and molecular effects were reduced by the applications of SB239063 and Hex. We concluded that nicotine stimulates the invasion and metastasis of colon cancer cells in vitro via activation of the nAchRs and the p38 MAPK downstream signaling pathway. Therefore, p38 MAPK may have potential as a therapeutic target for smoking-related human colorectal cancer metastasis.

  2. Oxidant stress-induced loss of IRS-1 and IRS-2 proteins in rat skeletal muscle: role of p38 MAPK

    PubMed Central

    Archuleta, Tara L.; Lemieux, Andrew M.; Saengsirisuwan, Vitoon; Teachey, Mary K.; Lindborg, Katherine A.; Kim, John S.; Henriksen, Erik J.

    2009-01-01

    Oxidative stress is characterized as the imbalance between the cellular production of oxidants and cellular antioxidant defenses and contributes to the development of numerous cardiovascular and metabolic disorders, including hypertension and insulin resistance. The effects of prolonged oxidant stress in vitro on the insulin-dependent glucose transport system in mammalian skeletal muscle are not well understood. The current study examined the in vitro effects of low-level oxidant stress (60-90 μM, H2O2) for 4 hr on insulin-stimulated (5 mU/ml) glucose transport activity (2-deoxyglucose uptake) and on protein expression of critical insulin signaling factors (insulin receptor (IR), IR substrates IRS-1 and IRS-2, phosphatidylinositol-3-kinase (PI3-kinase), Akt, and glycogen synthase kinase-3 (GSK-3)) in isolated soleus muscle of lean Zucker rats. This oxidant stress exposure caused significant (50%, p<0.05) decreases in insulin-stimulated glucose transport activity that was associated with selective loss of IRS-1 (59%) and IRS-2 (33%) proteins, increased (64%) relative IRS-1 Ser307 phosphorylation, and decreased phosphorylation of Akt Ser473 (50%) and GSK-3ß Ser9 (43%). Moreover, enhanced (37%) phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) was observed. Selective inhibition of p38 MAPK (10 μM A304000) prevented a significant portion (29%) of the oxidant stress-induced loss of IRS-1 (but not IRS-2) protein and allowed partial recovery of the impaired insulin-stimulated glucose transport activity. These results indicate that in vitro oxidative stress in mammalian skeletal muscle leads to substantial insulin resistance of distal insulin signaling and glucose transport activity, associated with a selective loss of IRS-1 protein, in part due to a p38 MAPK-dependent mechanism. PMID:19703555

  3. Mitogen-activated protein kinase p38b interaction with delta class glutathione transferases from the fruit fly, Drosophila melanogaster.

    PubMed

    Wongtrakul, Jeerang; Sukittikul, Suchada; Saisawang, Chonticha; Ketterman, Albert J

    2012-01-01

    Glutathione transferases (GSTs) are a family of multifunctional enzymes involved in xenobiotic biotransformation, drug metabolism, and protection against oxidative damage. The p38b mitogen-activated protein kinase is involved in cellular stress response. This study screened interactions between Drosophila melanogaster Meigen (Diptera: Drosophilidae) Delta class glutathione transferases (DmGSTs) and the D. melanogaster p38b MAPK. Therefore, 12 DmGSTs and p38b kinase were obtained as recombinant proteins. The study showed that DmGSTD8 and DmGSTD11b significantly increased p38b activity toward ATF2 and jun, which are transcription factor substrates. DmGSTD3 and DmGSTD5 moderately increased p38b activity for jun. In addition, GST activity in the presence of p38b was also measured. It was found that p38b affected substrate specificity toward CDNB (1-chloro-2,4-dinitrobenzene) and DCNB (1,2-dichloro-4-nitrobenzene) of several GST isoforms, i.e., DmGSTD2, DmGSTD5, DmGSTD8, and DmGSTD11b. The interaction of a GST and p38b can affect the substrate specificity of either enzyme, which suggests induced conformational changes affecting catalysis. Similar interactions do not occur for all the Delta enzymes and p38b, which suggests that these interactions could be specific. PMID:23438069

  4. Baicalein inhibits MMP-2 expression in human ovarian cancer cells by suppressing the p38 MAPK-dependent NF-κB signaling pathway.

    PubMed

    Yan, Hao; Xin, Shaobin; Wang, Hui; Ma, Jing; Zhang, Heng; Wei, Hailing

    2015-07-01

    Matrix metalloproteinases (MMPs) secreted by ovarian cancer play essential roles in tumor invasion and metastasis. In this study, we investigated the effect of baicalein, which is isolated from the traditional Chinese herbal medicine Scutellaria baicalensis Georgi, on human ovarian cancer cell lines by measuring MMP-2 expression, invasive potential, and the underlying molecular mechanisms. Analysis of MMP-2 was carried out by western blots and RT-PCR. The invasion ability of ovarian cancer cells was determined using a Transwell invasion assay. Nuclear factor-κB (NF-κB) and p38 MAPK activation was assessed by western blots. The results of the present study showed that baicalein reduced the expression of MMP-2 in a dose-dependent manner and the invasion of ovarian cancer cells was also significantly suppressed by baicalein. We also found that baicalein reduced the activation of NF-κB signaling molecules; in addition, the MMP-2 expression and invasion ability of ovarian cancer cells were abolished with the treatment of the NF-κB inhibitor, pyrrolidine dithiocarbamate. However, the addition of p38 MAPK inhibitor SB203580 significantly reduced the activation of NF-κB; meanwhile, baicalein was shown to exert an inhibitory effect on p38 activation. Furthermore, the MMP-2 expression and invasion ability of ovarian cancer cells were significantly inhibited by SB203580. In conclusion, baicalein inhibits the MMP-2 expression and invasion ability of ovarian cancer cells, possibly by the p38 MAPK-dependent NF-κB signaling pathway; these findings may provide insights into the potential of using baicalein as a therapeutic strategy against ovarian cancer.

  5. Role of p38 MAPK and NF-kB for chemokine release in coculture of human eosinophils and bronchial epithelial cells.

    PubMed

    Wong, C K; Wang, C B; Ip, W K; Tian, Y P; Lam, C W K

    2005-01-01

    Eosinophils are principal effector cells of inflammation in allergic asthma, characterized by their accumulation and infiltration at inflammatory sites mediated by the chemokine eotaxin and their interaction with adhesion molecules expressed on bronchial epithelial cells. We investigated the modulation of nuclear factor-kappaB (NF-kappaB) and the mitogen-activated protein kinase (MAPK) pathway on the in vitro release of chemokines including regulated upon activation normal T cell expressed and secreted (RANTES), monokine induced by interferon-gamma (MIG), monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-8, and interferon-inducible protein-10 (IP-10) upon the interaction of human bronchial epithelial BEAS-2B cells and eosinophils. Gene expression of chemokines was evaluated by RT-PCR and the induction amount of chemokines quantified by cytometric bead array. NF-kappaB and p38 MAPK activities were assessed by electrophoretic mobility shift assay and Western blot, respectively. The interaction of eosinophils and BEAS-2B cells was found to up-regulate the gene expression of the chemokines IL-8, MCP-1, MIG, RANTES and IP-10 expression in BEAS-2B cells, and to significantly elevate the release of the aforementioned chemokines except RANTES in a coculture of BEAS-2B cells and eosinophils. IkappaB-alpha phosphorylation inhibitor, BAY 11-7082, and p38 MAPK inhibitor, SB 203580 could decrease the release of IL-8, IP-10 and MCP-1 in the coculture. Together, the above results show that the induction of the release of chemokines in a coculture of epithelial cells and eosinophils are regulated by p38 MAPK and NF-kappaB activities of BEAS-2B cells, at least partly, through intercellular contact. Our findings therefore shed light on the future development of more effective agents for allergic and inflammatory diseases.

  6. An interplay between the p38 MAPK pathway and AUBPs regulates c-fos mRNA stability during mitogenic stimulation.

    PubMed

    Degese, Maria Sol; Tanos, Tamara; Naipauer, Julian; Gingerich, Tim; Chiappe, Diego; Echeverria, Pablo; LaMarre, Jonathan; Gutkind, J Silvio; Coso, Omar A

    2015-04-01

    Mitogen-activated protein kinase (MAPK) pathways constitute key regulatory elements linking extracellular stimuli to nuclear gene expression. Immediate-early responsive genes (IEGs) of the activator protein 1 (AP-1) family, such as fos, achieve peak expression levels shortly after cells are stimulated with growth factors and sharply decrease thereafter. Several AU-rich binding proteins (AUBPs), including HuR (Hu-antigen R, Elav-like protein 1, ELAVL1) and KSRP (far upstream element-binding protein 2, KHSRP) bind to a fos AU-rich element (ARE) present in the 3'-UTR (untranslated region) of fos mRNA regulating its stability by a still poorly defined mechanism. We show in the present study that, whereas HuR binds and stabilizes transcribed reporter mRNAs bearing the fos 3'-UTR, KSRP counteracts this effect. Furthermore, we found that fos mRNA stability and HuR phosphorylation status are dependent on the activity of p38 MAPK in both epithelial cells and fibroblasts upon proliferative stimulation. Analysing PPI (protein-protein interaction) networks, we performed a thorough query of interacting proteins for p38 MAPKs, HuR and other AUBPs upon growth factor stimulation. This revealed novel HuR interactors including inhibitors of protein phosphatase 2 (PP2A) activity. Over-expression of two of these interactors, pp32 and APRIL (acidic leucine-rich nuclear phosphoprotein 32 family member B, ANP32B) and pharmacological inhibition of PP2A stabilized a fos reporter mRNA. Our results indicate that p38 MAPK regulates fos mRNA decay by affecting the state of phosphorylation of HuR while controlling yet to be fully elucidated PP regulatory networks.

  7. p38 mitogen-activated protein kinase mediates IL-8 induction by the ribotoxin deoxynivalenol in human monocytes

    SciTech Connect

    Islam, Zahidul; Gray, Jennifer S.; Pestka, James J. . E-mail: pestka@msu.edu

    2006-06-15

    The effects of the ribotoxic trichothecene deoxynivalenol (DON) on mitogen-activated protein kinase (MAPK)-mediated IL-8 expression were investigated in cloned human monocytes and peripheral blood mononuclear cells (PBMC). DON (250 to 1000 ng/ml) induced both IL-8 mRNA and IL-8 heteronuclear RNA (hnRNA), an indicator of IL-8 transcription, in the human U937 monocytic cell line in a concentration-dependent manner. Expression of IL-8 hnRNA, mRNA and protein correlated with p38 phosphorylation and was completely abrogated by the p38 MAPK inhibitor SB203580. DON at 500 ng/ml similarly induced p38-dependent IL-8 protein and mRNA expression in PBMC cultures from healthy volunteers. Significantly increased IL-6 and IL-1{beta} intracellular protein and mRNA expression was also observed in PBMC treated with DON (500 ng/ml) which were also partially p38-dependent. Flow cytometry of PBMC revealed that DON-induced p38 phosphorylation varied among individuals relative to both threshold toxin concentrations (25-100 ng/ml) and relative increases in percentages of phospho-p38{sup +} cells. DON-induced p38 activation occurred exclusively in the CD14{sup +} monocyte population. DON was devoid of agonist activity for human Toll-like receptors 2, 3, 4, 5, 7, 8 and 9. However, two other ribotoxins, emetine and anisomycin, induced p38 phosphorylation in PBMC similarly to DON. Taken together, these data suggest that (1) p38 activation was required for induction of IL-8 and proinflammatory gene expression in the monocyte and (2) DON induced p38 activation in human monocytes via the ribotoxic stress response.

  8. mda-7 (IL-24) mediates selective apoptosis in human melanoma cells by inducing the coordinated overexpression of the GADD family of genes by means of p38 MAPK

    PubMed Central

    Sarkar, Devanand; Su, Zao-Zhong; Lebedeva, Irina V.; Sauane, Moira; Gopalkrishnan, Rahul V.; Valerie, Kristoffer; Dent, Paul; Fisher, Paul B.

    2002-01-01

    Subtraction hybridization identified melanoma differentiation-associated gene-7 (mda-7) as a gene induced during terminal differentiation in human melanoma cells. On the basis of structure, chromosomal localization and cytokine-like properties, mda-7 is classified as IL-24. Administration of mda-7/IL-24 by means of a replication-incompetent adenovirus (Ad.mda-7) induces apoptosis selectively in diverse human cancer cells without inducing harmful effects in normal fibroblast or epithelial cells. The present studies investigated the mechanism underlying this differential apoptotic effect. Infection of melanoma cells, but not normal immortal melanocytes, with Ad.mda-7 induced a time- and dose-dependent increase in expression, mRNA and protein, of a family of growth arrest and DNA damage (GADD)-inducible genes, which correlated with induction of apoptosis. Among the members of the GADD family of genes, GADD153, GADD45α, and GADD34 displayed marked, and GADD45γ showed minimal induction. Treatment of melanoma cells with SB203580, a selective inhibitor of the p38 mitogen-activated protein kinase (MAPK) pathway, effectively inhibited Ad.mda-7-induced apoptosis. Additional support for an involvement of the p38 MAPK pathway in Ad.mda-7-mediated apoptosis was documented by using an adenovirus expressing a dominant negative mutant of p38 MAPK. Infection with Ad.mda-7 increased the phosphorylation of p38 MAPK and heat shock protein 27 in melanoma cells but not in normal immortal melanocytes. In addition, SB203580 effectively inhibited Ad.mda-7-mediated induction of the GADD family of genes in a time- and dose-dependent manner, and it effectively blocked Ad.mda-7-mediated down-regulation of the antiapoptotic protein BCL-2. Inhibition of GADD genes by an antisense approach either alone or in combination also effectively blocked Ad.mda-7-induced apoptosis in melanoma cells. These results support the hypothesis that Ad.mda-7 mediates induction of the GADD family of genes by means

  9. Inhibition of p38 Mitogen-Activated Protein Kinase Enhances the Apoptosis Induced by Oxidized Low-Density Lipoprotein in Endothelial Progenitor Cells.

    PubMed

    Tie, Guodong; Yan, Jinglian; Messina, Julia A; Raffai, Robert L; Messina, Louis M

    2015-01-01

    Oxidized low-density lipoprotein (oxLDL) is an important risk factor in the development of atherosclerosis. oxLDL has been shown to decrease endothelial progenitor cell (EPC) number by inducing apoptosis. p38 mitogen-activated protein kinase (MAPK) was shown to be activated by oxLDL and participated in the regulation of EPC number and function. However, the role of p38 remains unknown. Here, we show that oxLDL-induced p38 phosphorylation in EPCs is time and dose dependent. Treatment with antioxidant N-acetyl cysteine restored oxLDL-induced p38 phosphorylation to basal levels. LOX-1-blocking antibody also significantly decreased oxLDL-induced p38 phosphorylation. Interestingly, TUNEL staining showed that pretreatment with the p38 inhibitor SB203580 further increased oxLDL-induced apoptosis in EPCs. In accordance with these findings, pretreatment with SB203580 further attenuated Akt phosphorylation in EPCs challenged with oxLDL, indicating an interaction between Akt and p38 MAPK pathways. In agreement, inhibition of p38 MAPK further attenuated Akt phosphorylation and increased apoptosis in EPCs isolated from hypercholesterolemic ApoE-/- mice. In conclusion, p38 MAPK serves as an anti-apoptotic pathway by supporting Akt activity when EPCs are challenged with oxLDL. PMID:27031525

  10. Curcumol Inhibits Growth and Induces Apoptosis of Colorectal Cancer LoVo Cell Line via IGF-1R and p38 MAPK Pathway.

    PubMed

    Wang, Juan; Huang, Fengxiang; Bai, Zhun; Chi, Bixia; Wu, Jiacai; Chen, Xu

    2015-08-20

    Curcumol, isolated from the traditional medical plant Rhizoma Curcumae, is the bioactive component of Zedoary oil, whose potential anti-tumor effect has attracted considerable attention in recent years. Though many researchers have reported curcumol and its bioactivity, the potential molecular mechanism for its anti-cancer effect in colorectal cancer LoVo cells still remains unclear. In the present study, we found that curcumol showed growth inhibition and induced apoptosis of LoVo cells in a dose- and time-dependent manner. The occurrence of its proliferation inhibition and apoptosis came with suppression of IGF-1R expression, and then increased the phosphorylation of p38 mitogen activated protein kinase (MAPK), which might result in a cascade response by inhibiting the CREB survival pathway and finally triggered Bax/Bcl-2 and poly(ADP-ribose) polymerase 1 (PARP-1) apoptosis signals. Moreover, curcumol inhibited colorectal cancer in xenograft models of nude mice. Immunohistochemical and Western blot analysis revealed that curcumol could decrease the expression of ki-67, Bcl-2 as well as CREB1, and increase the expression of Bax and the phosphorylation of p38, which were consistent with our in vitro study. Overall, our in vitro and in vivo data confirmed the anti-cancer activity of curcumol, which was related to a significant inhibition of IGF-1R and activation of p38 MAPKs, indicating that curcumol may be a potential anti-tumor agent for colorectal carcinoma therapy.

  11. LY2228820 dimesylate, a selective inhibitor of p38 mitogen-activated protein kinase, reduces angiogenic endothelial cord formation in vitro and in vivo.

    PubMed

    Tate, Courtney M; Blosser, Wayne; Wyss, Lisa; Evans, Glenn; Xue, Qi; Pan, Yong; Stancato, Louis

    2013-03-01

    LY2228820 dimesylate is a highly selective small molecule inhibitor of p38α and p38β mitogen-activated protein kinases (MAPKs) that is currently under clinical investigation for human malignancies. p38 MAPK is implicated in a wide range of biological processes, in particular those that support tumorigenesis. One such process, angiogenesis, is required for tumor growth and metastasis, and many new cancer therapies are therefore directed against the tumor vasculature. Using an in vitro co-culture endothelial cord formation assay, a surrogate of angiogenesis, we investigated the role of p38 MAPK in growth factor- and tumor-driven angiogenesis using LY2228820 dimesylate treatment and by shRNA gene knockdown. p38 MAPK was activated in endothelial cells upon growth factor stimulation, with inhibition by LY2228820 dimesylate treatment causing a significant decrease in VEGF-, bFGF-, EGF-, and IL-6-induced endothelial cord formation and an even more dramatic decrease in tumor-driven cord formation. In addition to involvement in downstream cytokine signaling, p38 MAPK was important for VEGF, bFGF, EGF, IL-6, and other proangiogenic cytokine secretion in stromal and tumor cells. LY2228820 dimesylate results were substantiated using p38α MAPK-specific shRNA and shRNA against the downstream p38 MAPK effectors MAPKAPK-2 and HSP27. Using in vivo models of functional neoangiogenesis, LY2228820 dimesylate treatment reduced hemoglobin content in a plug assay and decreased VEGF-A-stimulated vascularization in a mouse ear model. Thus, p38α MAPK is implicated in tumor angiogenesis through direct tumoral effects and through reduction of proangiogenic cytokine secretion via the microenvironment.

  12. LY2228820 dimesylate, a selective inhibitor of p38 mitogen-activated protein kinase, reduces angiogenic endothelial cord formation in vitro and in vivo.

    PubMed

    Tate, Courtney M; Blosser, Wayne; Wyss, Lisa; Evans, Glenn; Xue, Qi; Pan, Yong; Stancato, Louis

    2013-03-01

    LY2228820 dimesylate is a highly selective small molecule inhibitor of p38α and p38β mitogen-activated protein kinases (MAPKs) that is currently under clinical investigation for human malignancies. p38 MAPK is implicated in a wide range of biological processes, in particular those that support tumorigenesis. One such process, angiogenesis, is required for tumor growth and metastasis, and many new cancer therapies are therefore directed against the tumor vasculature. Using an in vitro co-culture endothelial cord formation assay, a surrogate of angiogenesis, we investigated the role of p38 MAPK in growth factor- and tumor-driven angiogenesis using LY2228820 dimesylate treatment and by shRNA gene knockdown. p38 MAPK was activated in endothelial cells upon growth factor stimulation, with inhibition by LY2228820 dimesylate treatment causing a significant decrease in VEGF-, bFGF-, EGF-, and IL-6-induced endothelial cord formation and an even more dramatic decrease in tumor-driven cord formation. In addition to involvement in downstream cytokine signaling, p38 MAPK was important for VEGF, bFGF, EGF, IL-6, and other proangiogenic cytokine secretion in stromal and tumor cells. LY2228820 dimesylate results were substantiated using p38α MAPK-specific shRNA and shRNA against the downstream p38 MAPK effectors MAPKAPK-2 and HSP27. Using in vivo models of functional neoangiogenesis, LY2228820 dimesylate treatment reduced hemoglobin content in a plug assay and decreased VEGF-A-stimulated vascularization in a mouse ear model. Thus, p38α MAPK is implicated in tumor angiogenesis through direct tumoral effects and through reduction of proangiogenic cytokine secretion via the microenvironment. PMID:23335506

  13. Transcriptional activation of MMP-13 by periodontal pathogenic LPS requires p38 MAP kinase.

    PubMed

    Rossa, Carlos; Liu, Min; Bronson, Paul; Kirkwood, Keith L

    2007-01-01

    Matrix metalloprotease-13 (MMP-13) is induced by pro-inflammatory cytokines and increased expression is associated with a number of pathological conditions such as tumor metastasis, osteoarthritis, rheumatoid arthritis and periodontal diseases. MMP-13 gene regulation and the signal transduction pathways activated in response to bacterial LPS are largely unknown. In these studies, the role of the mitogen-activated protein kinase (MAPK) pathways in the regulation of MMP-13 induced by lipopolysaccharide was investigated. Lipopolysaccharide from Escherichia coli and Actinobacillus actinomycetemcomitans significantly (P < 0.05) increased MMP-13 steady-state mRNA (average of 27% and 46% increase, respectively) in murine periodontal ligament fibroblasts. MMP-13 mRNA induction was significantly reduced by inhibition of p38 MAP kinase. Immunoblot analysis indicated that p38 signaling was required for LPS-induced MMP-13 expression. Lipopolysaccharide induced proximal promoter reporter (-660/+32 mMMP-13) gene activity required p38 signaling. Collectively, these results indicate that lipopolysaccharide-induced murine MMP-13 is regulated by p38 signaling through a transcriptional mechanism.

  14. 2α-Hydroxyursolic Acid Inhibited Cell Proliferation and Induced Apoptosis in MDA-MB-231 Human Breast Cancer Cells through the p38/MAPK Signal Transduction Pathway.

    PubMed

    Jiang, Xue; Li, Tong; Liu, Rui Hai

    2016-03-01

    The mechanisms of action of 2α-hydroxyursolic acid in inhibiting cell proliferation and inducing apoptosis in MDA-MB-231 human breast cancer cells were investigated. The antiproliferative activity and cytotoxicity were determined by the methylene blue assay. The expression of proteins was determined using Western blot. 2α-Hydroxyursolic acid significantly inhibited MDA-MB-231 cell proliferation, and no cytotoxicity was observed at concentrations below 30 μM. 2α-Hydroxyursolic acid significantly down-regulated expressions of TRAF2, PCNA, cyclin D1, and CDK4 and up-regulated the expressions of p-ASK1, p-p38, p-p53, and p-21. 2α-Hydroxyursolic acid induced apoptosis in MDA-MB-231 cells by significantly increasing the Bax/Bcl-2 ratio and inducing the cleaved caspase-3. Additionally, treatment of SB203580, a p38 MAPK specific inhibitor, reversed the inhibition of PCNA, cyclin D1, and Bcl-2 expression induced by 2α-hydroxyursolic acid in MDA-MB-231 cells. These results suggested that 2α-hydroxyursolic acid exhibited anticancer activity through the inhibition of cell proliferation and the induction of apoptosis by regulating the p38/MAPK signal transduction pathway.

  15. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways

    PubMed Central

    Yan, Tingting; Zhao, Yan; Zhang, Xia; Lin, Xiaotong

    2016-01-01

    Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. Acetaldehyde, the most toxic metabolite of ethanol, mediates the brain tissue damage and cognitive dysfunction induced by chronic excessive alcohol consumption. In this study, the effect of astaxanthin, a marine bioactive compound, on acetaldehyde-induced cytotoxicity was investigated in SH-SY5Y cells. It was found that astaxanthin protected cells from apoptosis by ameliorating the effect of acetaldehyde on the expression of Bcl-2 family proteins, preventing the reduction of anti-apoptotic protein Bcl-2 and the increase of pro-apoptotic protein Bak induced by acetaldehyde. Further analyses showed that astaxanthin treatment inhibited acetaldehyde-induced reduction of the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB). Astaxanthin treatment also prevented acetaldehyde-induced increase of the level of activated p38 mitogen-activated protein kinase (MAPK) and decrease of the level of activated extracellular signal-regulated kinases (ERKs). Activation of Akt/CREB pathway promotes cell survival and is involved in the upregulation of Bcl-2 gene. P38MAPK plays a critical role in apoptotic events while ERKs mediates the inhibition of apoptosis. Thus, astaxanthin may inhibit acetaldehyde-induced apoptosis through promoting the activation of Akt/CREB and ERKs and blocking the activation of p38MAPK. In addition, astaxanthin treatment suppressed the oxidative stress induced by acetaldehyde and restored the antioxidative capacity of SH-SY5Y cells. Therefore, astaxanthin may protect cells against acetaldehyde-induced cytotoxicity through maintaining redox balance and modulating apoptotic and survival signals. The results suggest that astaxanthin treatment may be beneficial for preventing neurotoxicity associated with acetaldehyde and excessive alcohol consumption. PMID:26978376

  16. OSU-DY7, a novel D-tyrosinol derivative, mediates cytotoxicity in chronic lymphocytic leukaemia and Burkitt lymphoma through p38 mitogen-activated protein kinase pathway

    PubMed Central

    Bai, Li-Yuan; Ma, Yihui; Kulp, Samuel K.; Wang, Shu-Huei; Chiu, Chang-Fang; Frissora, Frank; Mani, Rajeswaran; Mo, Xiaokui; Jarjoura, David; Byrd, John C.; Chen, Ching-Shih; Muthusamy, Natarajan

    2013-01-01

    Summary Drug resistance and associated immune deregulation limit use of current therapies in chronic lymphocytic leukaemia (CLL), thus warranting alternative therapy development. Herein we demonstrate that OSU-DY7, a novel D-tyrosinol derivative targeting p38 mitogen-activated protein kinase (MAPK), mediates cytotoxicity in lymphocytic cell lines representing CLL (MEC-1), acute lymphoblastic leukaemia (697 cells), Burkitt lymphoma (Raji and Ramos) and primary B cells from CLL patients in a dose- and time-dependent manner. The OSU-DY7-induced cytotoxicity is dependent on caspase activation, as evidenced by induction of caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage and rescue of cytotoxicity by Z-VAD-FMK. Interestingly, OSU-DY7-induced cytotoxicity is mediated through activation of p38 MAPK, as evidenced by increased phosphorylation of p38 MAPK and downstream target protein MAPKAPK2. Pretreatment of B-CLL cells with SB202190, a specific p38 MAPK inhibitor, results in decreased MAPKAPK2 protein level with concomitant rescue of the cells from OSU-DY7-mediated cytotoxicity. Furthermore, OSU-DY7-induced cytotoxicity is associated with down regulation of p38 MAPK target BIRC5, that is rescued at protein and mRNA levels by SB202190. This study provides evidence for a role of OSU-DY7 in p38 MAPK activation and BIRC5 down regulation associated with apoptosis in B lymphocytic cells, thus warranting development of this alternative therapy for lymphoid malignancies. PMID:21470196

  17. The effect of RO3201195 and a pyrazolyl ketone P38 MAPK inhibitor library on the proliferation of Werner syndrome cells.

    PubMed

    Bagley, Mark C; Dwyer, Jessica E; Baashen, Mohammed; Dix, Matthew C; Murziani, Paola G S; Rokicki, Michal J; Kipling, David; Davis, Terence

    2016-01-21

    Microwave-assisted synthesis of the pyrazolyl ketone p38 MAPK inhibitor RO3201195 in 7 steps and 15% overall yield, and the comparison of its effect upon the proliferation of Werner Syndrome cells with a library of pyrazolyl ketones, strengthens the evidence that p38 MAPK inhibition plays a critical role in modulating premature cellular senescence in this progeroid syndrome and the reversal of accelerated ageing observed in vitro on treatment with SB203580. PMID:26611938

  18. The effect of RO3201195 and a pyrazolyl ketone P38 MAPK inhibitor library on the proliferation of Werner syndrome cells.

    PubMed

    Bagley, Mark C; Dwyer, Jessica E; Baashen, Mohammed; Dix, Matthew C; Murziani, Paola G S; Rokicki, Michal J; Kipling, David; Davis, Terence

    2016-01-21

    Microwave-assisted synthesis of the pyrazolyl ketone p38 MAPK inhibitor RO3201195 in 7 steps and 15% overall yield, and the comparison of its effect upon the proliferation of Werner Syndrome cells with a library of pyrazolyl ketones, strengthens the evidence that p38 MAPK inhibition plays a critical role in modulating premature cellular senescence in this progeroid syndrome and the reversal of accelerated ageing observed in vitro on treatment with SB203580.

  19. Ginkgo biloba extract mitigates liver fibrosis and apoptosis by regulating p38 MAPK, NF-κB/IκBα, and Bcl-2/Bax signaling

    PubMed Central

    Wang, Yuanyuan; Wang, Rong; Wang, Yujie; Peng, Ruqin; Wu, Yan; Yuan, Yongfang

    2015-01-01

    Background Liver fibrosis is the consequence of diverse liver injuries and can eventually develop into liver cirrhosis. Ginkgo biloba extract (GBE) is an extract from dried ginkgo leaves that has many pharmacological effects because of its various ingredients and has been shown to be hepatoprotective. Purpose and methods Aimed to investigate the underlying protective mechanisms of GBE on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Male Sprague Dawley rats were randomly divided into four groups: control group (C), model group (M), low-dose group (L), and high-dose group (H). Liver fibrosis was induced by CCl4 groups M, L, and H: group C was administered saline. In addition, GBE at different doses was used to treat groups L and H. Results The results of hematoxylin and eosin staining, Masson’s trichrome staining, a liver function index, and a liver fibrosis index showed that GBE application noticeably mitigated fibrosis and improved the function of the liver. The western blotting and immunohistochemistry analyses indicated that GBE reduced liver fibrosis not only by inhibiting p38 MAPK and NF-κBp65 via inhibition of IκBα degradation but also by inhibiting hepatocyte apoptosis via downregulation of Bax, upregulation of Bcl-2, and subsequent inhibition of caspase-3 activation. Inflammation-associated factors and hepatic stellate cell (HSC)-activation markers further demonstrated that GBE could effectively inhibit HSC activation and inflammation as a result of its regulation of p38 MAPK and nuclear factor-kappa B/IκBα signaling. Conclusion Our findings indicated a novel role for GBE in the treatment of liver fibrosis. The potential mechanisms may be associated with the following signaling pathways: 1) the p38 MAPK and nuclear factor-kappa B/IκBα signaling pathways (inhibiting inflammation and HSCs activation) and 2) the Bcl-2/Bax signaling pathway (inhibiting the apoptosis of hepatocytes). PMID:26664050

  20. SARS coronavirus papain-like protease induces Egr-1-dependent up-regulation of TGF-β1 via ROS/p38 MAPK/STAT3 pathway.

    PubMed

    Li, Shih-Wein; Wang, Ching-Ying; Jou, Yu-Jen; Yang, Tsuey-Ching; Huang, Su-Hua; Wan, Lei; Lin, Ying-Ju; Lin, Cheng-Wen

    2016-01-01

    SARS coronavirus (SARS-CoV) papain-like protease (PLpro) has been identified in TGF-β1 up-regulation in human promonocytes (Proteomics 2012, 12: 3193-205). This study investigates the mechanisms of SARS-CoV PLpro-induced TGF-β1 promoter activation in human lung epithelial cells and mouse models. SARS-CoV PLpro dose- and time-dependently up-regulates TGF-β1 and vimentin in A549 cells. Dual luciferase reporter assays with TGF-β1 promoter plasmids indicated that TGF-β1 promoter region between -175 to -60, the Egr-1 binding site, was responsible for TGF-β1 promoter activation induced by SARS-CoV PLpro. Subcellular localization analysis of transcription factors showed PLpro triggering nuclear translocation of Egr-1, but not NF-κB and Sp-1. Meanwhile, Egr-1 silencing by siRNA significantly reduced PLpro-induced up-regulation of TGF-β1, TSP-1 and pro-fibrotic genes. Furthermore, the inhibitors for ROS (YCG063), p38 MAPK (SB203580), and STAT3 (Stattic) revealed ROS/p38 MAPK/STAT3 pathway involving in Egr-1 dependent activation of TGF-β1 promoter induced by PLpro. In a mouse model with a direct pulmonary injection, PLpro stimulated macrophage infiltration into lung, up-regulating Egr-1, TSP-1, TGF-β1 and vimentin expression in lung tissues. The results revealed that SARS-CoV PLpro significantly triggered Egr-1 dependent activation of TGF-β1 promoter via ROS/p38 MAPK/STAT3 pathway, correlating with up-regulation of pro-fibrotic responses in vitro and in vivo. PMID:27173006

  1. Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

    SciTech Connect

    Changchien, Jung-Jung; Chen, Ying-Jung; Huang, Chia-Hui; Cheng, Tian-Lu; Lin, Shinne-Ren; Chang, Long-Sen

    2015-04-01

    Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressed c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression.

  2. Telmisartan, a possible PPAR-δ agonist, reduces TNF-α-stimulated VEGF-C production by inhibiting the p38MAPK/HSP27 pathway in human proximal renal tubular cells

    SciTech Connect

    Kimura, Hideki; Mikami, Daisuke; Kamiyama, Kazuko; Sugimoto, Hidehiro; Kasuno, Kenji; Takahashi, Naoki; Yoshida, Haruyoshi; Iwano, Masayuki

    2014-11-14

    Highlights: • TNF-α increased VEGF-C expression by enhancing phosphorylation of p38MAPK and HSP27. • Telmisartan decreased TNF-α-stimulated expression of VEGF-C. • Telmisartan suppressed TNF-α-induced phosphorylation of p38MAPK and HSP27. • Telmisartan activated endogenous PPAR-δ protein. • Telmisartan suppressed p38MAPK phosphorylation in a PPAR-δ-dependent manner. - Abstract: Vascular endothelial growth factor-C (VEGF-C) is a main inducer of inflammation-associated lymphangiogenesis in various inflammatory disorders including chronic progressive kidney diseases, for which angiotensin II receptor type 1 blockers (ARBs) are widely used as the main treatment. Although proximal renal tubular cells may affect the formation of lymphatic vessels in the interstitial area by producing VEGF-C, the molecular mechanisms of VEGF-C production and its manipulation by ARB have not yet been examined in human proximal renal tubular epithelial cells (HPTECs). In the present study, TNF-α dose-dependently induced the production of VEGF-C in HPTECs. The TNF-α-induced production of VEGF-C was mediated by the phosphorylation of p38MAPK and HSP27, but not by that of ERK or NFkB. Telmisartan, an ARB that can activate the peroxisome proliferator-activated receptor (PPAR), served as a PPAR-δ activator and reduced the TNF-α-stimulated production of VEGF-C. This reduction was partially attributed to a PPAR-δ-dependent decrease in p38MAPK phosphorylation. Our results indicate that TNF-α induced the production of VEGF-C in HPTECs by activating p38MAPK/HSP27, and this was partially inhibited by telmisartan in a PPAR-δ dependent manner. These results provide a novel insight into inflammation-associated lymphangiogenesis.

  3. l-glutamine Improves Skeletal Muscle Cell Differentiation and Prevents Myotube Atrophy After Cytokine (TNF-α) Stress Via Reduced p38 MAPK Signal Transduction.

    PubMed

    Girven, Matthew; Dugdale, Hannah F; Owens, Daniel J; Hughes, David C; Stewart, Claire E; Sharples, Adam P

    2016-12-01

    Tumour Necrosis Factor-Alpha (TNF-α) is chronically elevated in conditions where skeletal muscle loss occurs. As l-glutamine can dampen the effects of inflamed environments, we investigated the role of l-glutamine in both differentiating C2C12 myoblasts and existing myotubes in the absence/presence of TNF-α (20 ng · ml(-1) ) ± l-glutamine (20 mM). TNF-α reduced the proportion of cells in G1 phase, as well as biochemical (CK activity) and morphological differentiation (myotube number), with corresponding reductions in transcript expression of: Myogenin, Igf-I, and Igfbp5. Furthermore, when administered to mature myotubes, TNF-α induced myotube loss and atrophy underpinned by reductions in Myogenin, Igf-I, Igfbp2, and glutamine synthetase and parallel increases in Fox03, Cfos, p53, and Bid gene expression. Investigation of signaling activity suggested that Akt and ERK1/2 were unchanged, JNK increased (non-significantly) whereas P38 MAPK substantially and significantly increased in both myoblasts and myotubes in the presence of TNF-α. Importantly, 20 mM l-glutamine reduced p38 MAPK activity in TNF-α conditions back to control levels, with a corresponding rescue of myoblast differentiation and a reversal of atrophy in myotubes. l-glutamine resulted in upregulation of genes associated with growth and survival including; Myogenin, Igf-Ir, Myhc2 & 7, Tnfsfr1b, Adra1d, and restored atrophic gene expression of Fox03 back to baseline in TNF-α conditions. In conclusion, l-glutamine supplementation rescued suppressed muscle cell differentiation and prevented myotube atrophy in an inflamed environment via regulation of p38 MAPK. l-glutamine administration could represent an important therapeutic strategy for reducing muscle loss in catabolic diseases and inflamed ageing. J. Cell. Physiol. 9999: 231: 2720-2732, 2016. © 2016 Wiley Periodicals, Inc. PMID:26991744

  4. A Phase 1 Study of Oral ARRY-614, a p38 MAPK/Tie2 Dual Inhibitor, in Patients with Low or Intermediate-1 Risk Myelodysplastic Syndromes

    PubMed Central

    Garcia-Manero, Guillermo; Khoury, Hanna J.; Jabbour, Elias; Lancet, Jeffrey; Winski, Shannon L.; Cable, LouAnn; Rush, Selena; Maloney, Lara; Hogeland, Grant; Ptaszynski, Mieke; Calvo, Monica Cabrero; Bohanan, Zach; List, Alan; Kantarjian, Hagop; Komrokji, Rami

    2015-01-01

    Purpose Data suggest that activity of p38 MAPK and Tie2 kinase are dysregulated in MDS and may be targets for novel therapies. A Phase 1 study of ARRY-614, an oral dual inhibitor of p38 MAPK and Tie2, was conducted in patients with low or intermediate-1 International Prognostic Scoring System risk MDS to evaluate safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary responses by IWG 2006 criteria. Experimental Design Forty-five patients received ARRY-614 either QD or BID in dose escalation (400, 600, 900 or 1200 mg QD; 200 or 300 mg BID) or expansion cohorts. Results The 300 mg BID schedule was not tolerated, and a maximum tolerated dose was not reached for QD dosing. Treatment-related adverse events were primarily grade 1–2, with the most common being rash, diarrhea, dry skin, fatigue and anorexia. Inter-patient PK variability was high, although exposure was sufficient to achieve reduction in p38 MAPK activation in bone marrow and in the levels of circulating biomarkers. Disease responses were observed in 14 of 44 (32%) evaluable patients, 13 (93%) of whom had previously been treated with a hypomethylating agent. Responses were observed in all lineages, with 5 patients experiencing bilineage responses. Three of 25 RBC transfusion-dependent (TD) patients achieved transfusion independence (TI) and 5 of 7 platelet TD patients achieved TI. Conclusions ARRY-614 was well tolerated and has sufficient activity to warrant further evaluation in this patient population. We recommend 1200 mg QD as the optimal dose for further study. PMID:25480830

  5. Stress-dependent phosphorylation of myocardin-related transcription factor A (MRTF-A) by the p38MAPK/MK2 axis

    PubMed Central

    Ronkina, Natalia; Lafera, Juri; Kotlyarov, Alexey; Gaestel, Matthias

    2016-01-01

    Myocardin-related transcription factor A (MRTF-A) is a known actin-regulated transcriptional coactivator of serum response factor (SRF). Stimulation of actin polymerization activates MRTF-A by releasing it from G-actin and thus allowing it to bind to and activate SRF. Here, we compared protein phosphorylation in MK2/3-deficient cells rescued or not by ectopic expression of MK2 in two independent phosphoproteomic approaches using anisomycin-treated MEF cells and LPS-stimulated mouse macrophages, respectively. Two MRTF-A sites, Ser351 (corresponding to Ser312 in human) and Ser371 (Ser333 in human), showed significantly stronger phosphorylation (12-fold and 6-fold increase) in the cells expressing MK2. MRTF-A is phosphorylated at these sites in a stress-, but not in a mitogen-induced manner, and p38MAPK/MK2 catalytic activities are indispensable for this phosphorylation. MK2-mediated phosphorylation of MRTF-A at Ser312 and Ser333 was further confirmed in an in vitro kinase assay and using the phospho-protein kinase-D (PKD)-consensus motif antibody (anti-LXRXXpS/pT), the p38MAPK inhibitor BIRB-796, MK2/3-deficient cells and MRTF-A phospho-site mutants. Unexpectedly, dimerization, subcellular localization and translocation, interaction with actin, SRF or SMAD3 and transactivating potential of MRTF-A seem to be unaffected by manipulating the p38MAPK/MK2-dependent phosphorylations. Hence, MRTF-A is stress-dependently pho