Science.gov

Sample records for acid induced cell

  1. Polyunsaturated Branched-Chain Fatty Acid Geranylgeranoic Acid Induces Unfolded Protein Response in Human Hepatoma Cells

    PubMed Central

    Iwao, Chieko; Shidoji, Yoshihiro

    2015-01-01

    The acyclic diterpenoid acid geranylgeranoic acid (GGA) has been reported to induce autophagic cell death in several human hepatoma-derived cell lines; however, the molecular mechanism for this remains unknown. In the present study, several diterpenoids were examined for ability to induce XBP1 splicing and/or lipotoxicity for human hepatoma cell lines. Here we show that three groups of diterpenoids emerged: 1) GGA, 2,3-dihydro GGA and 9-cis retinoic acid induce cell death and XBP1 splicing; 2) all-trans retinoic acid induces XBP1 splicing but little cell death; and 3) phytanic acid, phytenic acid and geranylgeraniol induce neither cell death nor XBP1 splicing. GGA-induced ER stress/ unfolded protein response (UPR) and its lipotoxicity were both blocked by co-treatment with oleic acid. The blocking activity of oleic acid for GGA-induced XBP1 splicing was not attenuated by methylation of oleic acid. These findings strongly suggest that GGA at micromolar concentrations induces the so-called lipid-induced ER stress response/UPR, which is oleate-suppressive, and shows its lipotoxicity in human hepatoma cells. PMID:26186544

  2. Chrysophanic Acid Induces Necrosis but not Necroptosis in Human Renal Cell Carcinoma Caki-2 Cells

    PubMed Central

    Choi, Joon-Seok

    2016-01-01

    Background: Chrysophanic acid, also known as chrysophanol, has a number of biological activities. It enhances memory and learning abilities, raises superoxide dismutase activity, and has anti-cancer effects in several model systems. According to previous reports, chrysophanic acid-induced cell death shares features of necrotic cell death. However, the molecular and cellular processes underlying chrysophanic acid-induced cell death remain poorly understood. Methods: Chrysophanic acid-induced cell death was monitored by cell viability assay and Annexin V-propidium iodide (PI) staining of renal cell carcinoma Caki-2 cells. The induction of intracellular reactive oxygen species (ROS) by chrysophanic acid and the suppression of ROS by anti-oxidants were evaluated by 2′,7′-dichlorofluorescin diacetate staining. The expression and phosphorylation of proteins that are involved in apoptosis and necroptosis were detected by immunoblotting. Results: The extent of chrysophanic acid-induced cell death was concentration and time dependent, and dead cells mainly appeared in the PI-positive population, which is a major feature of necrosis, upon fluorescence-activated cell sorting analysis. Chrysophanic acid-induced cell death was associated with the generation of intracellular ROS, and this effect was reversed by pretreatment with N-acetyl cysteine. Chrysophanic acid-induced cell death was not associated with changes in apoptotic or necroptotic marker proteins. Conclusions: The cell death induced by chrysophanic acid resembled neither apoptotic nor necroptotic cell death in human renal cell carcinoma Caki-2 cells. PMID:27390736

  3. Bile acids induce hepatic differentiation of mesenchymal stem cells

    PubMed Central

    Sawitza, Iris; Kordes, Claus; Götze, Silke; Herebian, Diran; Häussinger, Dieter

    2015-01-01

    Mesenchymal stem cells (MSC) have the potential to differentiate into multiple cell lineages and their therapeutic potential has become obvious. In the liver, MSC are represented by stellate cells which have the potential to differentiate into hepatocytes after stimulation with growth factors. Since bile acids can promote liver regeneration, their influence on liver-resident and bone marrow-derived MSC was investigated. Physiological concentrations of bile acids such as tauroursodeoxycholic acid were able to initiate hepatic differentiation of MSC via the farnesoid X receptor and transmembrane G-protein-coupled bile acid receptor 5 as investigated with knockout mice. Notch, hedgehog, transforming growth factor-β/bone morphogenic protein family and non-canonical Wnt signalling were also essential for bile acid-mediated differentiation, whereas β-catenin-dependent Wnt signalling was able to attenuate this process. Our findings reveal bile acid-mediated signalling as an alternative way to induce hepatic differentiaion of stem cells and highlight bile acids as important signalling molecules during liver regeneration. PMID:26304833

  4. Docosahexaenoic Acid Induces Apoptosis in Primary Chronic Lymphocytic Leukemia Cells

    PubMed Central

    Gyan, Emmanuel; Tournilhac, Olivier; Halty, Christelle; Veyrat-Masson, Richard; Akil, Saïda; Berger, Marc; Hérault, Olivier; Callanan, Mary; Bay, Jacques-Olivier

    2015-01-01

    Chronic lymphocytic leukemia is an indolent disorder with an increased infectious risk remaining one of the main causes of death. Development of therapies with higher safety profile is thus a challenging issue. Docosahexaenoic acid (DHA, 22:6) is an omega-3 fatty acid, a natural compound of normal cells, and has been shown to display antitumor potency in cancer. We evaluated the potential in vitro effect of DHA in primary CLL cells. DHA induces high level of in vitro apoptosis compared to oleic acid in a dose-dependent and time-dependent manner. Estimation of IC50 was only of 4.813 µM, which appears lower than those reported in solid cancers. DHA is highly active on CLL cells in vitro. This observation provides a rationale for further studies aiming to understand its mechanisms of action and its potent in vivo activity. PMID:26734128

  5. Retinoic acid-induced neural differentiation of embryonal carcinoma cells.

    PubMed Central

    Jones-Villeneuve, E M; Rudnicki, M A; Harris, J F; McBurney, M W

    1983-01-01

    We have previously shown that the P19 line of embryonal carcinoma cells develops into neurons, astroglia, and fibroblasts after aggregation and exposure to retinoic acid. The neurons were initially identified by their morphology and by the presence of neurofilaments within their cytoplasm. We have more fully documented the neuronal nature of these cells by showing that their cell surfaces display tetanus toxin receptors, a neuronal cell marker, and that choline acetyl-transferase and acetyl cholinesterase activities appear coordinately in neuron-containing cultures. Several days before the appearance of neurons, there is a marked decrease in the amount of an embryonal carcinoma surface antigen, and at the same time there is a substantial decrease in the volumes of individual cells. Various retinoids were able to induce the development of neurons in cultures of aggregated P19 cells, but it did not appear that polyamine metabolism was involved in the effect. We have isolated a mutant clone which does not differentiate in the presence of any of the drugs which are normally effective in inducing differentiation of P19 cells. This mutant and others may help to elucidate the chain of events triggered by retinoic acid and other differentiation-inducing drugs. Images PMID:6656766

  6. Orexin A attenuates palmitic acid-induced hypothalamic cell death.

    PubMed

    Duffy, Cayla M; Nixon, Joshua P; Butterick, Tammy A

    2016-09-01

    Palmitic acid (PA), an abundant dietary saturated fatty acid, contributes to obesity and hypothalamic dysregulation in part through increase in oxidative stress, insulin resistance, and neuroinflammation. Increased production of reactive oxygen species (ROS) as a result of PA exposure contributes to the onset of neuronal apoptosis. Additionally, high fat diets lead to changes in hypothalamic gene expression profiles including suppression of the anti-apoptotic protein B cell lymphoma 2 (Bcl-2) and upregulation of the pro-apoptotic protein B cell lymphoma 2 associated X protein (Bax). Orexin A (OXA), a hypothalamic peptide important in obesity resistance, also contributes to neuroprotection. Prior studies have demonstrated that OXA attenuates oxidative stress induced cell death. We hypothesized that OXA would be neuroprotective against PA induced cell death. To test this, we treated an immortalized hypothalamic cell line (designated mHypoA-1/2) with OXA and PA. We demonstrate that OXA attenuates PA-induced hypothalamic cell death via reduced caspase-3/7 apoptosis, stabilization of Bcl-2 gene expression, and reduced Bax/Bcl-2 gene expression ratio. We also found that OXA inhibits ROS production after PA exposure. Finally, we show that PA exposure in mHypoA-1/2 cells significantly reduces basal respiration, maximum respiration, ATP production, and reserve capacity. However, OXA treatment reverses PA-induced changes in intracellular metabolism, increasing basal respiration, maximum respiration, ATP production, and reserve capacity. Collectively, these results support that OXA protects against PA-induced hypothalamic dysregulation, and may represent one mechanism through which OXA can ameliorate effects of obesogenic diet on brain health. PMID:27449757

  7. Lysophosphatidic acid-induced chemotaxis of bone cells.

    SciTech Connect

    Karagiosis, Sue A.; Masiello, Lisa M.; Bollinger, Nikki; Karin, Norm J.

    2006-07-01

    Lysophosphatidic acid (LPA) is a platelet-derived bioactive lipid that is postulated to regulate wound healing. LPA activates G protein-coupled receptors to induce Ca2+ signaling in MC3T3-E1 pre-osteoblasts, and is a potent chemotactic stimulus for these cells. Since bone fracture healing requires the migration of osteoblast progenitors, we postulate that LPA is among the factors that stimulate bone repair. UMR 106-01 cells, which express a more mature osteoblastic phenotype than MC3T3-E1 cells, did not migrate in response to LPA, although they express LPA receptors and exhibit LPA-induced Ca2+ signals. This suggests that LPA differentially induces pre-osteoblast chemotaxis, consistent with our hypothesis that LPA stimulates the motility of osteoblast progenitors during bone healing. LPA-stimulated MC3T3-E1 cells exhibit striking changes in morphology and F-actin architecture, and phosphatidylinositol-3 kinase (PI3K) is required for motility-associated cytoskeletal rearrangements in many cell types. We found a dose-dependent reduction in LPA-induced osteoblast migration when cells also were treated with the PI3K inhibitor, LY294002. Treatment of many cell types with LPA is associated with an autocrine/paracrine transactivation of the EGF receptor (EGFR) via shedding of surface-tethered EGFR ligands, a phenomenon often required for LPA-induced chemotaxis. MC3T3-E1 cells express multiple EGFR ligands (epigen, epiregulin, HB-EGF and amphiregulin) and migrated in response to EGF. However, while EGF-stimulated motility in MC3T3-E1 cells was blocked by an EGFR inhibitor, there was no significant effect on LPA-induced chemotaxis. Activation of MAP kinases is a hallmark of EGFR-mediated signaling, and EGF treatment of MC3T3-E1 cells led to a strong stimulation of ERK1/2 kinase. In contrast, LPA induced only a minor elevation in ERK activity. Thus, it is likely that the increase in ERK activity by LPA is related to cell proliferation associated with lipid treatment. We

  8. Acid-induced secretory cell metaplasia in hamster bronchi

    SciTech Connect

    Christensen, T.G.; Lucey, E.C.; Breuer, R.; Snider, G.L.

    1988-02-01

    Hamsters were exposed to an intratracheal instillation of 0.5 ml of 0.08 N nitric, hydrochloric, or sulfuric acid to determine their airway epithelial response. Three weeks after exposure, the left intrapulmonary bronchi in Alcian blue/PAS-strained paraffin sections were evaluated for the amount of secretory product in the airway epithelium as a measure of secretory cell metaplasia (SCM). Compared to saline-treated control animals, all three acids caused statistically significant SCM. In addition to the bronchial lesion, all three acids caused similar interstitial fibrosis, bronchiolectasis, and bronchiolization of alveoli that varied in individual animals from mild to severe. In a separate experiment to study the persistence of the SCM, hamsters treated with a single instillation of 0.1 N nitric acid showed significant SCM 3, 7, and 17 weeks after exposure. There was a high correlation (r = 0.96) between a subjective assessment of SCM and objective assessment using a digital image-analysis system. We conclude that protons induce SCM independently of the associated anion; the SCM persists at least 17 weeks. Sulfuric acid is an atmospheric pollutant and nitric acid may form locally on the mucosa of lungs exposed to nitrogen dioxide. These acids may contribute to the development of maintenance of the SCM seen in the conducting airways of humans with chronic obstructive pulmonary disease.

  9. Nerve cell death induced in vivo by kainic acid and quinolinic acid does not involve apoptosis.

    PubMed

    Ignatowicz, E; Vezzani, A M; Rizzi, M; D'Incalci, M

    1991-11-01

    We investigated whether in vivo excitotoxicity was mediated by a mechanism of programmed cell death called apoptosis. Neurotoxic doses of kainic acid (1.2 nmol) and quinolinic acid (120 nmol) were unilaterally injected in the dorsal hippocampus of anesthetized rats. Eight or 16 h later the animals were killed and DNA was extracted from the injected hippocampi. DNA from mouse thymocytes exposed to methylprednisolone (10(-5) M for 6 h at 37 degrees C) was used as a positive control of apoptotic cells. No typical 'ladder' of DNA fragments (multimers of approximately 200 Kb) which characterizes apoptosis was seen in hippocampal cells after toxic doses of kainic or quinolinic acid, as assessed by agarose gel electrophoresis. This suggests that hippocampal nerve cell death induced in vivo by the excitotoxins is not mediated by apoptosis. PMID:1839770

  10. Transcriptomic changes induced by mycophenolic acid in gastric cancer cells

    PubMed Central

    Dun, Boying; Sharma, Ashok; Xu, Heng; Liu, Haitao; Bai, Shan; Zeng, Lingwen; She, Jin-Xiong

    2014-01-01

    Background: Inhibition of inosine monophosphate dehydrogenase (IMPDH) by mycophenolic acid (MPA) can inhibit proliferation and induce apoptosis in cancer cells. This study investigated the underlying molecular mechanisms of MPA’s anticancer activity. Methods: A gastric cancer cell line (AGS) was treated with MPA and gene expression at different time points was analyzed using Illumina whole genome microarrays and selected genes were confirmed by real-time RT-PCR. Results: Transcriptomic profiling identified 1070 genes with ≥2 fold changes and 85 genes with >4 fold alterations. The most significantly altered biological processes by MPA treatment include cell cycle, apoptosis, cell proliferation and migration. MPA treatment altered at least ten KEGG pathways, of which eight (p53 signaling, cell cycle, pathways in cancer, PPAR signaling, bladder cancer, protein processing in ER, small cell lung cancer and MAPK signaling) are cancer-related. Among the earliest cellular events induced by MPA is cell cycle arrest which may be caused by six molecular pathways: 1) up-regulation of cyclins (CCND1 and CCNE2) and down-regulation of CCNA2 and CCNB1, 2) down-regulation of cyclin-dependent kinases (CDK4 and CDK5); 3) inhibition of cell division related genes (CDC20, CDC25B and CDC25C) and other cell cycle related genes (MCM2, CENPE and PSRC1), 4) activation of p53, which activates the cyclin-dependent kinase inhibitors (CDKN1A), 5) impaired spindle checkpoint function and chromosome segregation (BUB1, BUB1B, BOP1, AURKA, AURKB, and FOXM1); and 6) reduction of availability of deoxyribonucleotides and therefore DNA synthesis through down-regulation of the RRM1 enzyme. Cell cycle arrest is followed by inhibition of cell proliferation, which is mainly attributable to the inhibition of the PI3K/AKT/mTOR pathway, and caspase-dependent apoptosis due to up-regulation of the p53 and FAS pathways. Conclusions: These results suggest that MPA has beneficial anticancer activity through

  11. Quinolinic acid induces cell apoptosis in PC12 cells through HIF-1-dependent RTP801 activation.

    PubMed

    Huang, Xiaojia; Yang, Kaiyong; Zhang, Yi; Wang, Qiang; Li, Yongjin

    2016-04-01

    Neurological disease comprises a series of disorders featuring brain dysfunction and neuronal cell death. Among the factors contributing to neuronal death, excitotoxicity induced by excitatory amino acids, such as glutamate, plays a critical role. However, the mechanisms about how the excitatory amino acids induce neuronal death remain elucidated. In this study, we investigated the role of HIF-1α (hypoxia inducible factor-1α) and RTP801 in cell apoptosis induced by quinolinic acid (QUIN), a glutamatergic agonist, in PC12 cells. We found that QUIN at 5 μM increased the expression of HIF-1α significantly with a peak at 24 h. After the treatment with QUIN (5-20 μM) for 24 h, the cells exhibited decreased viability and cell apoptosis with a concomitant increased expression of apoptosis related proteins. QUIN treatment also induced the generation of intracellular reactive oxygen species and RTP801 up-regulation in a HIF-1α-dependent manner that were inhibited by 2-methoxyestradiol, a HIF-1α inhibitor. Importantly, HIF-1 or RTP801 invalidation by siRNA rescued the cell apoptosis induced by QUIN or cobalt chloride, a chemical inducer of HIF-1. Taken together, these findings support the concept that neurotoxicity induced by QUIN is associated with HIF-1-dependent RTP801 activation and provide insight into the potential of RTP801 inhibitor in treatment of neurological disorders. PMID:26738727

  12. Retinoic acid induces cells cultured from oral squamous cell carcinomas to become anti-angiogenic.

    PubMed Central

    Lingen, M. W.; Polverini, P. J.; Bouck, N. P.

    1996-01-01

    Retinoids have shown great promise as chemopreventive against the development of squamous cell carcinomas of the upper aerodigestive tract. However, the exact mechanism by which they block new tumors from arising is unknown. Here, we report that 13-cis- and all-trans-retinoic acid, used at clinically achievable doses of 10(-6) mol/L or less, can directly and specifically affect cell lines cultured from oral squamous cell carcinomas, inducing them to switch from an angiogenic to an anti-angiogenic phenotype. Although retinoic-acid-treated and untreated tumor cells make the same amount of interleukin-8, the major inducer of neovascularization produced by such tumor lines, they vary in production of inhibitory activity. Only the retinoic-acid-treated cells produce a potent angio-inhibitory activity that is able to block in vitro migration of endothelial cells toward tumor cell conditioned media and to halt neovascularization induced by such media in the rat cornea. Anti-angiogenic activity is induced in the tumor cells by low doses of retinoids in the absence of toxicity with a kinetics that suggest that it could be contributing to the effectiveness of the retinoids as chemopreventive agents. Images Figure 6 PMID:8686749

  13. Phenylpropenoic Acid Glucoside from Rooibos Protects Pancreatic Beta Cells against Cell Death Induced by Acute Injury

    PubMed Central

    Himpe, Eddy; Cunha, Daniel A.; Song, Imane; Bugliani, Marco; Marchetti, Piero; Cnop, Miriam; Bouwens, Luc

    2016-01-01

    Objective Previous studies demonstrated that a phenylpropenoic acid glucoside (PPAG) from rooibos (Aspalathus linearis) extract had anti-hyperglycemic activity and significant protective effects on the pancreatic beta cell mass in a chronic diet-induced diabetes model. The present study evaluated the cytoprotective effect of the phytochemical on beta cells exposed to acute cell stress. Methods Synthetically prepared PPAG was administered orally in mice treated with a single dose of streptozotocin to acutely induce beta cell death and hyperglycemia. Its effect was assessed on beta cell mass, proliferation and apoptotic cell death. Its cytoprotective effect was also studied in vitro on INS-1E beta cells and on human pancreatic islet cells. Results Treatment with the phytochemical PPAG protected beta cells during the first days after the insult against apoptotic cell death, as evidenced by TUNEL staining, and prevented loss of expression of anti-apoptotic protein BCL2 in vivo. In vitro, PPAG protected INS-1E beta cells from streptozotocin-induced apoptosis and necrosis in a BCL2-dependent and independent way, respectively, depending on glucose concentration. PPAG also protected human pancreatic islet cells against the cytotoxic action of the fatty acid palmitate. Conclusions These findings show the potential use of PPAG as phytomedicine which protects the beta cell mass exposed to acute diabetogenic stress. PMID:27299564

  14. Fatty Acid-Induced T Cell Loss Greases Liver Carcinogenesis.

    PubMed

    Shalapour, Shabnam; Karin, Michael

    2016-05-10

    A new study has added loss of CD4(+) T cells caused by aberrant lipid metabolism to the list of mechanisms promoting nonalcoholic steatohepatitis progression to liver cancer (Ma et al., 2016). Exposure of CD4(+) T cells to free linoleic acid causes their ROS-mediated depletion, thereby favoring liver cancer growth. PMID:27166937

  15. Retinoic acid-primed human dendritic cells inhibit Th9 cells and induce Th1/Th17 cell differentiation.

    PubMed

    Rampal, Ritika; Awasthi, Amit; Ahuja, Vineet

    2016-07-01

    All-trans-retinoic acid plays a central role in mucosal immunity, where it promotes its synthesis by up-regulating CD103 expression on dendritic cells, induces gut tropic (α4β7(+) and CCR9(+)) T cells, and inhibits Th1/Th17 differentiation. Recently, murine studies have highlighted the proinflammatory role of retinoic acid in maintaining inflammation under a variety of pathologic conditions. However, as a result of limited human data, we investigated the effect of retinoic acid on human dendritic cells and CD4(+) T cell responses in the presence of polarizing (Th1/Th9/Th17) and inflammatory (LPS-induced dendritic cells) conditions. We report a novel role of retinoic acid in an inflammatory setup, where retinoic acid-primed dendritic cells (retinoic acid-monocyte-derived dendritic cells) up-regulated CCR9(+)T cells, which were observed to express high levels of IFN-γ in the presence of Th1/Th17 conditions. Retinoic acid-monocyte-derived dendritic cells, under Th17 conditions, also favored the induction of IL-17(+) T cells. Furthermore, in the presence of TGF-β1 and IL-4, retinoic acid-monocyte-derived dendritic cells inhibited IL-9 and induced IFN-γ expression on T cells. Experiments with naïve CD4(+) T cells, activated in the presence of Th1/Th17 conditions and absence of DCs, indicated that retinoic acid inhibited IFN-γ and IL-17 expression on T cells. These data revealed that in the face of inflammatory conditions, retinoic acid, in contrast from its anti-inflammatory role, could maintain or aggravate the intestinal inflammation. PMID:26980802

  16. Gambogic acid induces apoptotic cell death in T98G glioma cells.

    PubMed

    Thida, Mya; Kim, Dae Won; Tran, Thi Thu Thuy; Pham, Minh Quan; Lee, Heesu; Kim, Inki; Lee, Jae Wook

    2016-02-01

    Gambogic acid (GA), a natural product with a xanthone structure, has a broad range of anti-proliferative effects on cancer cell lines. We evaluated GA for its cytotoxic effects on T98G glioblastoma cells. GA exhibited potent anti-proliferative activity and induced apoptosis in T98G glioblastoma cells in a dose-dependent manner. Incubation of cells with GA revealed apoptotic features including increased Bax and AIF expression, cytochrome c release, and cleavage of caspase-3, -8, -9, and PARP, while Bcl-2 expression was downregulated. Furthermore, GA induced reactive oxygen species (ROS) generation in T98G cells. Our results indicate that GA increases Bax- and AIF-associated apoptotic signaling in glioblastoma cells. PMID:26631318

  17. Induced accumulation of oleanolic acid and ursolic acid in cell suspension cultures of Uncaria tomentosa.

    PubMed

    Feria-Romero, Iris; Lazo, Elizabeth; Ponce-Noyola, Teresa; Cerda-García-Rojas, Carlos M; Ramos-Valdivia, Ana C

    2005-06-01

    Increasing sucrose from 20 to 50 g l(-1) in Uncaria tomentosa cell suspension cultures enhanced ursolic acid and oleanolic acid production from 129 +/- 61 to 553 +/- 193 microg g(-1) cell dry wt. The maximal concentration of both triterpenes (1680 +/- 39 microg g(-1) cell dry wt) was 8 days after elicitation by jasmonic acid, while yeast extract or citrus pectin treatments produced 1189 +/- 20 or 1120 +/- 26 microg g(-1) cell dry wt, respectively. The ratio of ursolic acid:oleanolic acid was constant at 70:30. PMID:16086245

  18. Luteolin prevents uric acid-induced pancreatic β-cell dysfunction

    PubMed Central

    Ding, Ying; Shi, Xuhui; Shuai, Xuanyu; Xu, Yuemei; Liu, Yun; Liang, Xiubin; Wei, Dong; Su, Dongming

    2014-01-01

    Abstract Elevated uric acid causes direct injury to pancreatic β-cells. In this study, we examined the effects of luteolin, an important antioxidant, on uric acid-induced β-cell dysfunction. We first evaluated the effect of luteolin on nitric oxide (NO) formation in uric acid-stimulated Min6 cells using the Griess method. Next, we performed transient transfection and reporter assays to measure transcriptional activity of nuclear factor (NF)-κB. Western blotting assays were also performed to assess the effect of luteolin on the expression of MafA and inducible NO synthase (iNOS) in uric acid-treated cells. Finally, we evaluated the effect of luteolin on uric acid-induced inhibition of glucose-stimulated insulin secretion (GSIS) in Min6 cells and freshly isolated mouse pancreatic islets. We found that luteolin significantly inhibited uric acid-induced NO production, which was well correlated with reduced expression of iNOS mRNA and protein. Furthermore, decreased activity of NF-κB was implicated in inhibition by luteolin of increased iNOS expression induced by uric acid. Besides, luteolin significantly increased MafA expression in Min6 cells exposed to uric acid, which was reversed by overexpression of iNOS. Moreover, luteolin prevented uric acid-induced inhibition of GSIS in both Min6 cells and mouse islets. In conclusion, luteolin protects pancreatic β-cells from uric acid-induced dysfunction and may confer benefit on the protection of pancreatic β-cells in hyperuricemia-associated diabetes. PMID:25050113

  19. The Polyunsaturated Fatty Acids Arachidonic Acid and Docosahexaenoic Acid Induce Mouse Dendritic Cells Maturation but Reduce T-Cell Responses In Vitro

    PubMed Central

    Carlsson, Johan A.; Wold, Agnes E.; Sandberg, Ann-Sofie; Östman, Sofia M.

    2015-01-01

    Long-chain polyunsaturated fatty acids (PUFAs) might regulate T-cell activation and lineage commitment. Here, we measured the effects of omega-3 (n-3), n-6 and n-9 fatty acids on the interaction between dendritic cells (DCs) and naïve T cells. Spleen DCs from BALB/c mice were cultured in vitro with ovalbumin (OVA) with 50 μM fatty acids; α-linolenic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid or oleic acid and thereafter OVA-specific DO11.10 T cells were added to the cultures. Fatty acids were taken up by the DCs, as shown by gas chromatography analysis. After culture with arachidonic acid or DHA CD11c+ CD11b+ and CD11c+ CD11bneg DCs expressed more CD40, CD80, CD83, CD86 and PDL-1, while IAd remained unchanged. However, fewer T cells co-cultured with these DCs proliferated (CellTrace Violetlow) and expressed CD69 or CD25, while more were necrotic (7AAD+). We noted an increased proportion of T cells with a regulatory T cell (Treg) phenotype, i.e., when gating on CD4+ FoxP3+ CTLA-4+, CD4+ FoxP3+ Helios+ or CD4+ FoxP3+ PD-1+, in co-cultures with arachidonic acid- or DHA-primed DCs relative to control cultures. The proportion of putative Tregs was inversely correlated to T-cell proliferation, indicating a suppressive function of these cells. With arachidonic acid DCs produced higher levels of prostaglandin E2 while T cells produced lower amounts of IL-10 and IFNγ. In conclusion arachidonic acid and DHA induced up-regulation of activation markers on DCs. However arachidonic acid- and DHA-primed DCs reduced T-cell proliferation and increased the proportion of T cells expressing FoxP3, indicating that these fatty acids can promote induction of regulatory T cells. PMID:26619195

  20. In vitro evidence that phosphatidylcholine protects against indomethacin/bile acid-induced injury to cells

    PubMed Central

    Dial, Elizabeth J.; Dawson, Paul A.

    2014-01-01

    Indomethacin is a powerful analgesic nonsteroidal anti-inflammatory drug (NSAID), but is limited in use by its primary side effect to cause gastrointestinal bleeding and serious injury. One factor important for exacerbating NSAID injury is the presence of bile acids, which may interact with indomethacin to form toxic mixed micelles in the gut. The development of a safer gastrointestinal formulation of indomethacin that is chemically complexed with phosphatidylcholine (PC-indomethacin) may offer an improved therapeutic agent, particularly in the presence of bile acid, but its potential protective mechanism is incompletely understood. Intestinal epithelial cells (IEC-6) were tested for injury with indomethacin (alone and plus various bile acids) compared with PC-indomethacin (alone and plus bile acids). To explore a role for bile acid uptake into cells as a requirement for NSAID injury, studies were performed using Madin-Darby canine kidney cells transfected with the apical sodium-dependent bile acid transporter (ASBT). Indomethacin, but not PC-indomethacin, was directly and dose-dependently injurious to IEC-6 cells. Similarly, the combination of any bile acid plus indomethacin, but not PC-indomethacin, induced cell injury. The expression of ASBT had a modest effect on the acute cytotoxicity of indomethacin in the presence of some conjugated bile acids. Complexing PC with indomethacin protected against the acute intestinal epithelial injury caused by indomethacin regardless of the presence of bile acids. The presence of luminal bile acid, but not its carrier-mediated uptake into the enterocyte, is required for acute indomethacin-induced cell injury. It is likely that initial cell damage induced by indomethacin occurs at or near the cell membrane, an effect exacerbated by bile acids and attenuated by PC. PMID:25477376

  1. Retinoic acid induces Sertoli cell paracrine signals for spermatogonia differentiation but cell autonomously drives spermatocyte meiosis

    PubMed Central

    Raverdeau, Mathilde; Gely-Pernot, Aurore; Féret, Betty; Dennefeld, Christine; Benoit, Gérard; Davidson, Irwin; Chambon, Pierre; Mark, Manuel; Ghyselinck, Norbert B.

    2012-01-01

    Direct evidence for a role of endogenous retinoic acid (RA), the active metabolite of vitamin A in the initial differentiation and meiotic entry of spermatogonia, and thus in the initiation of spermatogenesis is still lacking. RA is synthesized by dedicated enzymes, the retinaldehyde dehydrogenases (RALDH), and binds to and activates nuclear RA receptors (RARA, RARB, and RARG) either within the RA-synthesizing cells or in the neighboring cells. In the present study, we have used a combination of somatic genetic ablations and pharmacological approaches in vivo to show that during the first, prepubertal, spermatogenic cycle (i) RALDH-dependent synthesis of RA by Sertoli cells (SC), the supporting cells of the germ cell (GC) lineage, is indispensable to initiate differentiation of A aligned into A1 spermatogonia; (ii) RARA in SC mediates the effects of RA, possibly through activating Mafb expression, a gene whose Drosophila homolog is mandatory to GC differentiation; (iii) RA synthesized by premeiotic spermatocytes cell autonomously induces meiotic initiation through controlling the RAR-dependent expression of Stra8. Furthermore, we show that RA of SC origin is no longer necessary for the subsequent spermatogenic cycles but essential to spermiation. Altogether, our data establish that the effects of RA in vivo on spermatogonia differentiation are indirect, via SC, but direct on meiotic initiation in spermatocytes, supporting thereby the notion that, contrary to the situation in the female, RA is necessary to induce meiosis in the male. PMID:23012458

  2. Cyclosporine A and palmitic acid treatment synergistically induce cytotoxicity in HepG2 cells

    SciTech Connect

    Luo, Yi Rana, Payal; Will, Yvonne

    2012-06-01

    Immunosuppressant cyclosporine A (CsA) treatment can cause severe side effects. Patients taking immunosuppressant after organ transplantation often display hyperlipidemia and obesity. Elevated levels of free fatty acids have been linked to the etiology of metabolic syndromes, nonalcoholic fatty liver and steatohepatitis. The contribution of free fatty acids to CsA-induced toxicity is not known. In this study we explored the effect of palmitic acid on CsA-induced toxicity in HepG2 cells. CsA by itself at therapeutic exposure levels did not induce detectible cytotoxicity in HepG2 cells. Co-treatment of palmitic acid and CsA resulted in a dose dependent increase in cytotoxicity, suggesting that fatty acid could sensitize cells to CsA-induced cytotoxicity at the therapeutic doses of CsA. A synergized induction of caspase-3/7 activity was also observed, indicating that apoptosis may contribute to the cytotoxicity. We demonstrated that CsA reduced cellular oxygen consumption which was further exacerbated by palmitic acid, implicating that impaired mitochondrial respiration might be an underlying mechanism for the enhanced toxicity. Inhibition of c-Jun N-terminal kinase (JNK) attenuated palmitic acid and CsA induced toxicity, suggesting that JNK activation plays an important role in mediating the enhanced palmitic acid/CsA-induced toxicity. Our data suggest that elevated FFA levels, especially saturated FFA such as palmitic acid, may be predisposing factors for CsA toxicity, and patients with underlying diseases that would elevate free fatty acids may be susceptible to CsA-induced toxicity. Furthermore, hyperlipidemia/obesity resulting from immunosuppressive therapy may aggravate CsA-induced toxicity and worsen the outcome in transplant patients. -- Highlights: ► Palmitic acid and cyclosporine (CsA) synergistically increased cytotoxicity. ► The impairment of mitochondrial functions may contribute to the enhanced toxicity. ► Inhibition of JNK activity attenuated

  3. Protective Effects of Oleic Acid Against Palmitic Acid-Induced Apoptosis in Pancreatic AR42J Cells and Its Mechanisms

    PubMed Central

    Ahn, Joung Hoon; Kim, Min Hye; Kwon, Hyung Joo; Choi, Soo Young

    2013-01-01

    Palmitic acid (PAM), one of the most common saturated fatty acid (SFA) in animals and plants, has been shown to induce apoptosis in exocrine pancreatic AR42J cells. In this study, we investigated cellular mechanisms underlying protective effects of oleic acid (OLA) against the lipotoxic actions of PAM in AR42J cells. Exposure of cells to long-chain SFA induced apoptotic cell death determined by MTT cell viability assay and Hoechst staining. Co-treatment of OLA with PAM markedly protected cells against PAM-induced apoptosis. OLA significantly attenuated the PAM-induced increase in the levels of pro-apoptotic Bak protein, cleaved forms of apoptotic proteins (caspase-3, PARP). On the contrary, OLA restored the decreased levels of anti-apoptotic Bcl-2 family proteins (Bcl-2, Bcl-xL, and Mcl-1) in PAM-treated cells. OLA also induced up-regulation of the mRNA expression of Dgat2 and Cpt1 genes which are involved in triacylglycerol (TAG) synthesis and mitochondrial β-oxidation, respectively. Intracellular TAG accumulation was increased by OLA supplementation in accordance with enhanced expression of Dgat2 gene. These results indicate that restoration of anti-apoptotic/pro-apoptotic protein balance from apoptosis toward cell survival is involved in the cytoprotective effects of OLA against PAM-induced apoptosis in pancreatic AR42J cells. In addition, OLA-induced increase in TAG accumulation and up-regulation of Dgat2 and Cpt1 gene expressions may be possibly associated in part with the ability of OLA to protect cells from deleterious actions of PAM. PMID:23440052

  4. Ascorbic acid protects against cadmium-induced endoplasmic reticulum stress and germ cell apoptosis in testes.

    PubMed

    Ji, Yan-Li; Wang, Zhen; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Meng, Xiu-Hong; Xu, De-Xiang

    2012-11-01

    Cadmium (Cd) is a testicular toxicant which induces endoplasmic reticulum (ER) stress and germ cell apoptosis in testes. This study investigated the effects of ascorbic acid on Cd-evoked ER stress and germ cell apoptosis in testes. Male mice were intraperitoneally injected with CdCl(2) (2.0 mg/kg). As expected, a single dose of Cd induced testicular germ cell apoptosis. Interestingly, Cd-triggered testicular germ cell apoptosis was almost completely inhibited in mice treated with ascorbic acid. Interestingly, ascorbic acid significantly attenuated Cd-induced upregulation of GRP78 in testes. In addition, ascorbic acid significantly attenuated Cd-triggered testicular IRE1α and eIF2α phosphorylation and XBP-1 activation, indicating that this antioxidant counteracts Cd-induced unfolded protein response (UPR) in testes. Finally, ascorbic acid significantly attenuated Cd-evoked upregulation of CHOP and JNK phosphorylation, two components in ER stress-mediated apoptotic pathway. In conclusion, ascorbic acid protects mice from Cd-triggered germ cell apoptosis via inhibiting ER stress and UPR in testes. PMID:22569276

  5. Acid-induced autophagy protects human lung cancer cells from apoptosis by activating ER stress.

    PubMed

    Xie, Wen-Yue; Zhou, Xiang-Dong; Li, Qi; Chen, Ling-Xiu; Ran, Dan-Hua

    2015-12-10

    An acidic tumor microenvironment exists widely in solid tumors. However, the detailed mechanism of cell survival under acidic stress remains unclear. The aim of this study is to clarify whether acid-induced autophagy exists and to determine the function and mechanism of autophagy in lung cancer cells. We have found that acute low pH stimulated autophagy by increasing LC3-positive punctate vesicles, increasing LC3 II expression levels and reducing p62 protein levels. Additionally, autophagy was inhibited by the addition of Baf or knockdown of Beclin 1, and cell apoptosis was increased markedly. In mouse tumors, the expression of cleaved caspase3 and p62 was enhanced by oral treatment with sodium bicarbonate, which can raise the intratumoral pH. Furthermore, the protein levels of ER stress markers, including p-PERK, p-eIF2α, CHOP, XBP-1s and GRP78, were also increased in response to acidic pH. The antioxidant NAC, which reduces ROS accumulation, alleviated acid-mediated ER stress and autophagy, and knocking down GRP78 reduced autophagy activation under acidic conditions, which suggests that autophagy was induced by acidic pH through ER stress. Taken together, these results indicate that the acidic microenvironment in non-small cell lung cancer cells promotes autophagy by increasing ROS-ER stress, which serves as a survival adaption in this setting. PMID:26559141

  6. Electrogenic responses induced by neutral amino acids in endoderm cells from Xenopus embryo.

    PubMed Central

    Bergman, C; Bergman, J

    1981-01-01

    1. Membrane potential measurements were carried out on endoderm cells from early Xenopus embryos in order to study neutral amino acid transport in non-excitable cells. 2. The electrical properties of the cell membrane were studied under normal conditions, then in the presence of various Na/K-pump inhibitors and at different Na, K and Cl concentrations in Ringer solution. Blockade of the Na/K-pump by ouabain, Li, cooling to 10 degrees C or low [Na]0 induces similar depolarizations of about 40 mV. 3. External application of various neutral L-amino acids induces reversible membrane depolarizations. The D-isomeric forms are found to be ineffective. The amino acid induced depolarizations are not accompanied by changes in membrane resistance. They do not show voltage dependence for potential changes of less than 40 mV. 4. The amino acid depolarization increases with increasing concentration and follows first order Michaëlian kinetics. Both the size and the time course of the amino acid depolarization depend on [Na]0. Increasing [Na]0 markedly increases the apparent affinity of the membrane receptor for amino acid. 5. Increasing [k]0 reduces the size of the amino acid response. Short exposures to either ouabain or Li do not alter the amino acid depolarization. However, p time course of the amino acid depolarization depend on [Na]0. Increasing [Na]0 markedly increases the apparent affinity of the membrane receptor for amino acid. 5. Increasing [k]0 reduces the size of the amino acid response. Short exposures to either ouabain or Li do not alter the amino acid depolarization. However, p time course of the amino acid depolarization depend on [Na]0. Increasing [Na]0 markedly increases the apparent affinity of the membrane receptor for amino acid. 5. Increasing [k]0 reduces the size of the amino acid response. Short exposures to either ouabain or Li do not alter the amino acid depolarization. However, prolonged exposure to pump inhibitors or marked alteration of the Na

  7. Proteomic Investigation into Betulinic Acid-Induced Apoptosis of Human Cervical Cancer HeLa Cells

    PubMed Central

    Xu, Tao; Pang, Qiuying; Zhou, Dong; Zhang, Aiqin; Luo, Shaman; Wang, Yang; Yan, Xiufeng

    2014-01-01

    Betulinic acid is a pentacyclic triterpenoid that exhibits anticancer functions in human cancer cells. This study provides evidence that betulinic acid is highly effective against the human cervical cancer cell line HeLa by inducing dose- and time-dependent apoptosis. The apoptotic process was further investigated using a proteomics approach to reveal protein expression changes in HeLa cells following betulinic acid treatment. Proteomic analysis revealed that there were six up- and thirty down-regulated proteins in betulinic acid-induced HeLa cells, and these proteins were then subjected to functional pathway analysis using multiple analysis software. UDP-glucose 6-dehydrogenase, 6-phosphogluconate dehydrogenase decarboxylating, chain A Horf6-a novel human peroxidase enzyme that involved in redox process, was found to be down-regulated during the apoptosis process of the oxidative stress response pathway. Consistent with our results at the protein level, an increase in intracellular reactive oxygen species was observed in betulinic acid-treated cells. The proteins glucose-regulated protein and cargo-selection protein TIP47, which are involved in the endoplasmic reticulum pathway, were up-regulated by betulinic acid treatment. Meanwhile, 14-3-3 family proteins, including 14-3-3β and 14-3-3ε, were down-regulated in response to betulinic acid treatment, which is consistent with the decrease in expression of the target genes 14-3-3β and 14-3-3ε. Furthermore, it was found that the antiapoptotic bcl-2 gene was down-regulated while the proapoptotic bax gene was up-regulated after betulinic acid treatment in HeLa cells. These results suggest that betulinic acid induces apoptosis of HeLa cells by triggering both the endoplasmic reticulum pathway and the ROS-mediated mitochondrial pathway. PMID:25148076

  8. Taxol induced apoptosis regulates amino acid transport in breast cancer cells.

    PubMed

    Wu, Yanyuan; Shen, Dejun; Chen, Zujian; Clayton, Sheila; Vadgama, Jaydutt V

    2007-03-01

    A major outcome from Taxol treatment is induction of tumor cell apoptosis. However, metabolic responses to Taxol-induced apoptosis are poorly understood. In this study, we hypothesize that alterations in specific amino acid transporters may affect the Taxol-induced apoptosis in breast cancer cells. In this case, the activity of the given transporter may serve as a biomarker that could provide a biological assessment of response to drug treatment. We have examined the mechanisms responsible for Taxol-induced neutral amino acid uptake by breast cancer cells, such as MCF-7, BT474, MDAMB231 and T47D. The biochemical and molecular studies include: (1) growth-inhibition (MTT); (2) transport kinetics: (3) substrate-specific inhibition; (4) effect of thiol-modifying agents NEM and NPM; (5) gene expression of amino acid transporters; and (6) apoptotic assays. Our data show that Taxol treatment of MCF-7 cells induced a transient increase in Na(+)-dependent transport of the neutral amino acid transporter B0 at both gene and protein level. This increase was attenuated by blocking the transporter in the presence of high concentrations of the substrate amino acid. Other neutral amino acid transporters such as ATA2 (System A) and ASC were not altered. Amino acid starvation resulted in the expected up-regulation of System A (ATA2) gene, but not for B0 and ASC. B0 was significantly down regulated. Taxol treatment had no significant effect on the uptake of arginine and glutamate as measured by System y(+) and X(-) (GC) respectively. Tunel assays and FACS cell cycle analysis demonstrated that both Taxol- and doxorubicin-induced upregulation of B0 transporter gene with accompanying increase in cell apoptosis, could be reversed partially by blocking the B0 transporter with high concentration of alanine, and/or by inhibiting the caspase pathway. Both Taxol and doxorubicin treatment caused a significant decrease in S-phase of the cell cycle. However, Taxol-induced an increase primarily

  9. Anacardic acid induces apoptosis-like cell death in the rice blast fungus Magnaporthe oryzae.

    PubMed

    Muzaffar, Suhail; Bose, Chinchu; Banerji, Ashok; Nair, Bipin G; Chattoo, Bharat B

    2016-01-01

    Anacardic acid (6-pentadecylsalicylic acid), extracted from cashew nut shell liquid, is a natural phenolic lipid well known for its strong antibacterial, antioxidant, and anticancer activities. Its effect has been well studied in bacterial and mammalian systems but remains largely unexplored in fungi. The present study identifies antifungal, cytotoxic, and antioxidant activities of anacardic acid in the rice blast fungus Magnaporthe oryzae. It was found that anacardic acid causes inhibition of conidial germination and mycelial growth in this ascomycetous fungus. Phosphatidylserine externalization, chromatin condensation, DNA degradation, and loss of mitochondrial membrane potential suggest that growth inhibition of fungus is mainly caused by apoptosis-like cell death. Broad-spectrum caspase inhibitor Z-VAD-FMK treatment indicated that anacardic acid induces caspase-independent apoptosis in M. oryzae. Expression of a predicted ortholog of apoptosis-inducing factor (AIF) was upregulated during the process of apoptosis, suggesting the possibility of mitochondria dependent apoptosis via activation of apoptosis-inducing factor. Anacardic acid treatment leads to decrease in reactive oxygen species rather than increase in reactive oxygen species (ROS) accumulation normally observed during apoptosis, confirming the antioxidant properties of anacardic acid as suggested by earlier reports. Our study also shows that anacardic acid renders the fungus highly sensitive to DNA damaging agents like ethyl methanesulfonate (EMS). Treatment of rice leaves with anacardic acid prevents M. oryzae from infecting the plant without affecting the leaf, suggesting that anacardic acid can be an effective antifungal agent. PMID:26381667

  10. The cumulus cell layer protects the bovine maturing oocyte against fatty acid-induced lipotoxicity.

    PubMed

    Lolicato, Francesca; Brouwers, Jos F; de Lest, Chris H A van; Wubbolts, Richard; Aardema, Hilde; Priore, Paola; Roelen, Bernard A J; Helms, J Bernd; Gadella, Bart M

    2015-01-01

    Mobilization of fatty acids from adipose tissue during metabolic stress increases the amount of free fatty acids in blood and follicular fluid and is associated with impaired female fertility. In a previous report, we described the effects of the three predominant fatty acids in follicular fluid (saturated palmitate and stearate and unsaturated oleate) on oocyte maturation and quality. In the current study, the effects of elevated fatty acid levels on cumulus cells were investigated. In a dose-dependent manner, the three fatty acids induced lipid storage in cumulus cells accompanied by an enhanced immune labeling of perilipin-2, a marker for lipid droplets. Lipidomic analysis confirmed incorporation of the administered fatty acids into triglyceride, resulting in a 3- to 6-fold increase of triglyceride content. In addition, palmitate selectively induced ceramide formation, which has been implicated in apoptosis. Indeed, of the three fatty acids tested, palmitate induced reactive oxygen species formation, caspase 3 activation, and mitochondria deterioration, leading to degeneration of the cumulus cell layers. This effect could be mimicked by addition of the ceramide-C2 analog and could be inhibited by the ceramide synthase inhibitor fumonisin-B1. Interfering with the intactness of the cumulus cell layers, either by mechanical force or by palmitate treatment, resulted in enhanced uptake of lipids in the oocyte and increased radical formation. Our results show that cumulus cells act as a barrier, protecting oocytes from in vitro induced lipotoxic effects. We suggest that this protective function of the cumulus cell layers is important for the developmental competence of the oocyte. The relevance of our findings for assisted reproduction technologies is discussed. PMID:25297544

  11. STRUCTURAL REMODELING OF PROTEOGLYCANS UPON RETINOIC ACID-INDUCED DIFFERENTIATION OF NCCIT CELLS*

    PubMed Central

    Gasimli, Leyla; Stansfield, Hope E.; Nairn, Alison V.; Liu, Haiying; Paluh, Janet L.; Yang, Bo; Dordick, Jonathan S.; Moremen, Kelley W.; Linhardt, Robert J.

    2012-01-01

    Pluripotent and multipotent cells become increasingly lineage restricted through differentiation. Alterations to the cellular proteoglycan composition and structure should accompany these changes to influence cell proliferation, delineation of tissues and acquisition of cell migration capabilities. Retinoic acid plays an important role in pre-patterning of the early embryo. Retinoic acid can be used in vitro to induce differentiation, causing pluripotent and multipotent cells to become increasingly lineage restricted. We examined retinoic acid-induced changes in the cellular proteoglycan composition of the well-characterized teratocarcinoma line NCCIT. Our analysis revealed changes in the abundance of transcripts for genes encoding core proteins, enzymes that are responsible for early and late linkage region biosynthesis, as well as enzymes for GAG chain extension and modification. Transcript levels for genes encoding core proteins used as backbones for polysaccharide synthesis revealed highly significant increases in expression of lumican and decorin, 1500-fold and 2800-fold, respectively. Similarly, glypican 3, glypican 5, versican and glypican 6 showed increases between 5 and 70-fold. Significant decreases in biglycan, serglycin, glypican 4, aggrecan, neurocan, CD74 and glypican 1 were observed. Disaccharide analysis of the glycans in heparin/heparan sulfate and chondroitin/dermatan sulfate revealed retinoic acid-induced changes restricted to chondroitin/dermatan sulfate glycans. Our study provides the first detailed analysis of changes in the glycosaminoglycan profile of human pluripotent cells upon treatment with the retinoic acid morphogen. PMID:23053635

  12. Structural remodeling of proteoglycans upon retinoic acid-induced differentiation of NCCIT cells.

    PubMed

    Gasimli, Leyla; Stansfield, Hope E; Nairn, Alison V; Liu, Haiying; Paluh, Janet L; Yang, Bo; Dordick, Jonathan S; Moremen, Kelley W; Linhardt, Robert J

    2013-07-01

    Pluripotent and multipotent cells become increasingly lineage restricted through differentiation. Alterations to the cellular proteoglycan composition and structure should accompany these changes to influence cell proliferation, delineation of tissues and acquisition of cell migration capabilities. Retinoic acid plays an important role in pre-patterning of the early embryo. Retinoic acid can be used in vitro to induce differentiation, causing pluripotent and multipotent cells to become increasingly lineage restricted. We examined retinoic acid-induced changes in the cellular proteoglycan composition of the well-characterized teratocarcinoma line NCCIT. Our analysis revealed changes in the abundance of transcripts for genes encoding core proteins, enzymes that are responsible for early and late linkage region biosynthesis, as well as enzymes for GAG chain extension and modification. Transcript levels for genes encoding core proteins used as backbones for polysaccharide synthesis revealed highly significant increases in expression of lumican and decorin, 1,500-fold and 2,800-fold, respectively. Similarly, glypican 3, glypican 5, versican and glypican 6 showed increases between 5 and 70-fold. Significant decreases in biglycan, serglycin, glypican 4, aggrecan, neurocan, CD74 and glypican 1 were observed. Disaccharide analysis of the glycans in heparin/heparan sulfate and chondroitin/dermatan sulfate revealed retinoic acid-induced changes restricted to chondroitin/dermatan sulfate glycans. Our study provides the first detailed analysis of changes in the glycosaminoglycan profile of human pluripotent cells upon treatment with the retinoic acid morphogen. PMID:23053635

  13. Perillyl alcohol and perillic acid induced cell cycle arrest and apoptosis in non small cell lung cancer cells.

    PubMed

    Yeruva, Laxmi; Pierre, Keon J; Elegbede, Abiodun; Wang, Robert C; Carper, Stephen W

    2007-11-18

    Plant products such as perillyl alcohol have been reported to possess anti-tumor activities against a number of human cancers though the mechanism of action has not yet been elucidated. The effects of perillyl alcohol (POH) and its metabolite perillic acid (PA) on the proliferation of non small cell lung cancer (NSCLC, A549, and H520) cells were investigated. Both POH and PA elicited dose-dependent cytotoxicity, induced cell cycle arrest and apoptosis with increasing expression of bax, p21 and caspase-3 activity in both the cell lines. Combination studies revealed that exposing the cells to an IC50 concentration of POH or PA sensitized the cells to cisplatin and radiation in a dose-dependent manner. These results indicate that POH and PA in combination therapy may have chemotherapeutic value against NSCLC. PMID:17888568

  14. Epoxyeicosatrienoic acids attenuate cigarette smoke extract-induced interleukin-8 production in bronchial epithelial cells.

    PubMed

    Ma, Wen-Jiang; Sun, Yan-Hong; Jiang, Jun-Xia; Dong, Xin-Wei; Zhou, Jian-Ying; Xie, Qiang-Min

    2015-03-01

    In response to endothelial cell activation, arachidonic acid can be converted by cytochrome P450 (CYP) epoxygenases to epoxyeicosatrienoic acids (EETs), which have potent vasodilator and anti-inflammatory properties. In this study, we investigated the effects of exogenous EETs on cigarette smoke extract (CSE)-induced inflammation in human bronchial epithelial cells (NCI-H292). We found that CSE inhibited the expression of CYP2C8 and mildly stimulated the expression of epoxide hydrolase 2 (EPHX2) but did not change the expression of CYP2J2. Treatment with 11,12-EET or 14,15-EET attenuated the CSE-induced release of interleukin (IL)-8 by inhibiting the phosphorylation of p38 mitogen-activated protein kinases (MAPKs). Our results demonstrated that CSE may reduce the anti-inflammatory ability of epithelial cells themselves by lowering the EET level. EETs from pulmonary epithelial cells may play a critical protective role on epithelial cell injury. PMID:25467970

  15. Cinnamic acid induces apoptotic cell death and cytoskeleton disruption in human melanoma cells

    PubMed Central

    2013-01-01

    Anticancer activities of cinnamic acid derivatives include induction of apoptosis by irreversible DNA damage leading to cell death. The present work aimed to compare the cytotoxic and genotoxic potential of cinnamic acid in human melanoma cell line (HT-144) and human melanocyte cell line derived from blue nevus (NGM). Viability assay showed that the IC50 for HT-144 cells was 2.4 mM, while NGM cells were more resistant to the treatment. The growth inhibition was probably associated with DNA damage leading to DNA synthesis inhibition, as shown by BrdU incorporation assay, induction of nuclear aberrations and then apoptosis. The frequency of cell death caused by cinnamic acid was higher in HT-144 cells. Activated-caspase 3 staining showed apoptosis after 24 hours of treatment with cinnamic acid 3.2 mM in HT-144 cells, but not in NGM. We observed microtubules disorganization after cinnamic acid exposure, but this event and cell death seem to be independent according to M30 and tubulin labeling. The frequency of micronucleated HT-144 cells was higher after treatment with cinnamic acid (0.4 and 3.2 mM) when compared to the controls. Cinnamic acid 3.2 mM also increased the frequency of micronucleated NGM cells indicating genotoxic activity of the compound, but the effects were milder. Binucleation and multinucleation counting showed similar results. We conclude that cinnamic acid has effective antiproliferative activity against melanoma cells. However, the increased frequency of micronucleation in NGM cells warrants the possibility of genotoxicity and needs further investigation. PMID:23701745

  16. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells.

    PubMed

    Song, Eun Ah; Kim, Hyeyoung

    2016-01-01

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells' molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies. PMID:27527148

  17. Protective effect of oleanolic acid on oxidized-low density lipoprotein induced endothelial cell apoptosis.

    PubMed

    Cao, Jianhua; Li, Guanghui; Wang, Meizhi; Li, Hui; Han, Zhiwu

    2015-10-01

    Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid, OA) is a naturally-occurring triterpenoid with various promising pharmacological properties. The present study was conducted to determine the protective effects of OA against oxidized low-density lipoprotein (ox-LDL) induced endothelial cell apoptosis and the possible underlying mechanisms. Our results showed that ox-LDL significantly decreased cell viability and induced apoptosis in human umbilical vein endothelial cells (HUVECs). OA in the co-treatment showed a protective effect against ox-LDL induced loss in cell viability and an increase in apoptosis, which was associated with the modulating effect of OA on ox-LDL induced hypoxia-inducible factor 1α(HIF-1α) expression. Moreover, our results showed that the modulating effect of OA against ox-LDL induced HIF-1α expression was obtained via inhibition of lipoprotein receptor 1 (LOX-1)/reactive oxygen species (ROS) signaling. Collectively, we suggested that the protective effect of OA against ox-LDL induced HUVEC apoptosis might, at least in part, be obtained via inhibition of the LOX-1/ROS/HIF-1α signaling pathway. PMID:26559024

  18. Eicosopentaneoic Acid and Other Free Fatty Acid Receptor Agonists Inhibit Lysophosphatidic Acid- and Epidermal Growth Factor-Induced Proliferation of Human Breast Cancer Cells

    PubMed Central

    Hopkins, Mandi M.; Zhang, Zhihong; Liu, Ze; Meier, Kathryn E.

    2016-01-01

    Many key actions of ω-3 (n-3) fatty acids have recently been shown to be mediated by two G protein-coupled receptors (GPCRs) in the free fatty acid receptor (FFAR) family, FFA1 (GPR40) and FFA4 (GPR120). n-3 Fatty acids inhibit proliferation of human breast cancer cells in culture and in animals. In the current study, the roles of FFA1 and FFA4 were investigated. In addition, the role of cross-talk between GPCRs activated by lysophosphatidic acid (LPA), and the tyrosine kinase receptor activated by epidermal growth factor (EGF), was examined. In MCF-7 and MDA-MB-231 human breast cancer cell lines, both LPA and EGF stimulated proliferation, Erk activation, Akt activation, and CCN1 induction. LPA antagonists blocked effects of LPA and EGF on proliferation in MCF-7 and MDA-MB-231, and on cell migration in MCF-7. The n-3 fatty acid eicosopentaneoic acid inhibited LPA- and EGF-induced proliferation in both cell lines. Two synthetic FFAR agonists, GW9508 and TUG-891, likewise inhibited LPA- and EGF-induced proliferation. The data suggest a major role for FFA1, which was expressed by both cell lines. The results indicate that n-3 fatty acids inhibit breast cancer cell proliferation via FFARs, and suggest a mechanism involving negative cross-talk between FFARS, LPA receptors, and EGF receptor. PMID:26821052

  19. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells

    PubMed Central

    Song, Eun Ah; Kim, Hyeyoung

    2016-01-01

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells’ molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies. PMID:27527148

  20. The 5-aminolevulinic acid-induced porphyrin biosynthesis in benign and malignant cells of the skin.

    PubMed

    Lang, K; Bolsen, K; Stahl, W; Ruzicka, T; Sies, H; Lehmann, P; Fritsch, C

    2001-12-01

    In fluorescence diagnosis and photodynamic therapy of neoplastic tissues 5-aminolevulinic acid is used to synthesize endogenous porphyrins as photosensitizers. The efficacy of neoplastic tissues to fluorescence diagnosis and photodynamic therapy is thought to be dependent on the total level of intralesional formed porphyrins. The available profiles of porphyrin metabolites in normal and in neoplastic cell lines after administration of 5-aminolevulinic acid vary considerably. Thus, this is the first in-vitro study which compares the porphyrin biosynthesis in normal skin cells (HaCaT, fibroblasts) with melanoma cells (Bro, SKMel-23, SKMel-28). After incubation with 1 mM 5-aminolevulinic acid, kinetics of porphyrin levels and metabolites were determined in the cells and the corresponding supernatants. Exogenous 5-aminolevulinic acid induced porphyrin formation in all cells with maximum values after an incubation period of 16-36 h. Increase of porphyrin levels varied from 10- to 80-fold (SKMel-28>HaCaT>fibroblasts>SKMel-23>Bro) with minimum 1.5 times higher levels of porphyrins in the supernatants than in the cells. In cells and supernatants protoporphyrin and coproporphyrin were the predominantly formed porphyrin metabolites. Metastatic melanoma cells (SKMel-23, SKMel-28) accumulated much higher porphyrin levels than primary melanoma cells (Bro). In conclusion, by optimizing the treatment modalities, especially the light source, topical photodynamic therapy (PDT) could become a treatment alternative of melanoma metastases in progressive disease. PMID:11748002

  1. Vasopressin induces release of arachidonic acid from vascular smooth muscle cells

    SciTech Connect

    Grillone, L.R.; Clark, M.A.; Heckman, G.; Schmidt, D.; Stassen, F.L.; Crooke, S.T.

    1986-05-01

    Cultured smooth muscle cells (A-10), derived from rat thoracic aorta, have vascular (V/sub 1/) vasopressin receptors. They have previously shown that these receptors mediate phosphatidylinositol turnover, Ca/sup 2 +/ efflux, and inhibition of isoproterenol-induced increases in cAMP. Here they studied the effect of vasopressin on arachidonic acid metabolism of A-10 cells. Cells were incubated for 18-20 hr with (/sup 3/H)-arachidonic acid (80 Ci/mmol). Vasopressin stimulated release of arachidonic acid in a time- and dose-dependent manner. Significant release of arachidonic acid was observed after 4 min with 10/sup -9/ M vasopressin. Maximum release was reached 4 min after addition of 10/sup -7/ M vasopressin (1100 dpm/10/sup 6/ cells). About 800 dmp were released after 1 and 4 min with 10/sup -7/ M and 10/sup -8/ M vasopressin, respectively. The vasopressin-stimulated release of arachidonic acid was blocked by the specific V/sub 1//V/sub 2/ vasopressin antagonist d(CH2)5D-Tyr(Et)VAVP. These data indicate that vascular smooth muscle cells increase arachidonic acid release in response to vasopressin. This response is likely mediated by V/sub 1/ receptors.

  2. Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration

    PubMed Central

    Fernández-Sánchez, Laura; Rondón, Netxibeth; Esquiva, Gema; Germain, Francisco; de la Villa, Pedro; Cuenca, Nicolás

    2015-01-01

    Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA)-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss. PMID:26379056

  3. Direct hepatic differentiation of mouse embryonic stem cells induced by valproic acid and cytokines

    PubMed Central

    Dong, Xue-Jun; Zhang, Guo-Rong; Zhou, Qing-Jun; Pan, Ruo-Lang; Chen, Ye; Xiang, Li-Xin; Shao, Jian-Zhong

    2009-01-01

    AIM: To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes. METHODS: Hepatic progenitor cells and then mature hepatocytes from mouse embryonic stem (ES) cells were obtained in a sequential manner, induced by valproic acid (VPA) and cytokines (hepatocyte growth factor, epidermal growth factor and insulin). Morphological changes of the differentiated cells were examined by phase-contrast microscopy and electron microscopy. Reverse transcription polymerase chain reaction and immunocytochemical analyses were used to evaluate the gene expression profiles of the VPA-induced hepatic progenitors and the hepatic progenitor-derived hepatocytes. Glycogen storage, cytochrome P450 activity, transplantation assay, differentiation of bile duct-like structures and tumorigenic analyses were performed for the functional identification of the differentiated cells. Furthermore, FACS and electron microscopy were used for the analyses of cell cycle profile and apoptosis in VPA-induced hepatic differentiated cells. RESULTS: Based on the combination of VPA and cytokines, mouse ES cells differentiated into a uniform and homogeneous cell population of hepatic progenitor cells and then matured into functional hepatocytes. The progenitor population shared several characteristics with ES cells and hepatic stem/progenitor cells, and represented a novel progenitor cell between ES and hepatic oval cells in embryonic development. The differentiated hepatocytes from progenitor cells shared typical characteristics with mature hepatocytes, including the patterns of gene expression, immunological markers, in vitro hepatocyte functions and in vivo capacity to restore acute-damaged liver function. In addition, the differentiation of hepatic progenitor cells from ES cells was accompanied by significant cell cycle arrest and selective survival of differentiating cells towards hepatic lineages. CONCLUSION: Hepatic cells

  4. Photoreactivation of ultraviolet radiation-induced release of arachidonic acid from marsupial cells.

    PubMed

    Kaleta, E W; Applegate, L A; Ley, R D

    1991-11-01

    Exposure of an established marsupial cell line, PtK2 (Potorous tridactylus), to ultraviolet radiation (UVR) from an FS-40 sunlamp (280-400 nm) resulted in a fluence-dependent release of radiolabeled arachidonic acid (AA) from cell membranes. Post-UVR, but not pre-UVR, exposure to photoreactivating light reversed UVR-induced pyrimidine dimers in DNA and suppressed the UVR-induced release of AA. These data indicate that DNA damage contributes to the release of AA from membrane phospholipids. PMID:1665911

  5. Proteomic analysis of differentially expressed proteins induced by salicylic acid in suspension-cultured ginseng cells

    PubMed Central

    Sun, Jiaman; Fu, Junfan; Zhou, Rujun

    2013-01-01

    In this study, optimized 2-DE sample preparation methodologies were established for suspension-cultured ginseng cells. Three commonly used protein extraction methods (Trichloroacetic acid-acetone, urea/thiourea and phenol extraction method) were evaluated for proteomic analysis of suspension cultures of ginseng. A comparative analysis of suspension-cultured ginseng cells proteome induced by salicylic acid (SA) was reported. The results demonstrated that phenol extraction method was the best method based on protein extraction efficiency and the good quality of 2-DE patterns for suspension-cultured ginseng cells. Fifteen differentially expressed proteins induced by salicylic acid in suspension-cultured ginseng cells were identified by MALDI-TOF-MS. These identified proteins were involved in defense and stress response, energy metabolism, signal transduction/transcription, protein synthesis and metabolism, and photosynthesis. Chaperonin 60, related to defense responses, was more abundant in suspension-cultured ginseng cells after application of SA. Vacuolar ATPase subunit B was newly induced in SA treatment. PMID:24600313

  6. Relationship between Mast Cells and the Colitis with Relapse Induced by Trinitrobenzesulphonic Acid in Wistar Rats

    PubMed Central

    Luchini, Ana Carolina; Costa de Oliveira, Déborah Mara; Pellizzon, Cláudia Helena; Di Stasi, Luiz Claudio; Gomes, José Carlos

    2009-01-01

    The present study aimed to clarify the role of mast cells in colitis with relapse induced in Wistar rats by trinitrobenzenosulphonic acid. Colitis induction increased the histamine concentration in the colon, which peaked on day 26. The number of mast cells, probably immature, was ten times higher on day 8. Different from animals infected with intestinal parasites, after colitis remission, mast cells do not migrate to the spleen, showing that mast cell proliferation presents different characteristics depending on the inflammation stimuli. Treatment with sulfasalazine, doxantrazole, quercetin, or nedocromil did not increase the histamine concentration or the mast cell number in the colon on day 26, thereby showing absence of degranulation of these cells. In conclusion, although mast cell proliferation is associated with colitis, these cells and their mediators appear to play no clear role in the colitis with relapses. PMID:19436763

  7. Heat shock protein 70-dependent protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells.

    PubMed

    Qin, Ying; Naito, Yuji; Handa, Osamu; Hayashi, Natsuko; Kuki, Aiko; Mizushima, Katsura; Omatsu, Tatsushi; Tanimura, Yuko; Morita, Mayuko; Adachi, Satoko; Fukui, Akifumi; Hirata, Ikuhiro; Kishimoto, Etsuko; Nishikawa, Taichiro; Uchiyama, Kazuhiko; Ishikawa, Takeshi; Takagi, Tomohisa; Yagi, Nobuaki; Kokura, Satoshi; Yoshikawa, Toshikazu

    2011-11-01

    Protection of the small intestine from mucosal injury induced by nonsteroidal anti-inflammatory drugs including acetylsalicylic acid is a critical issue in the field of gastroenterology. Polaprezinc an anti-ulcer drug, consisting of zinc and L-carnosine, provides gastric mucosal protection against various irritants. In this study, we investigated the protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of the RIE1 rat intestinal epithelial cell line. Confluent rat intestinal epithelial cells were incubated with 70 µM polaprezinc for 24 h, and then stimulated with or without 15 mM acetylsalicylic acid for a further 15 h. Subsequent cellular viability was quantified by fluorometric assay based on cell lysis and staining. Acetylsalicylic acid-induced cell death was also qualified by fluorescent microscopy of Hoechst33342 and propidium iodide. Heat shock proteins 70 protein expression after adding polaprezinc or acetylsalicylic acid was assessed by western blotting. To investigate the role of Heat shock protein 70, Heat shock protein 70-specific small interfering RNA was applied. Cell viability was quantified by fluorometric assay based on cell lysis and staining and apoptosis was analyzed by fluorescence-activated cell sorting. We found that acetylsalicylic acid significantly induced apoptosis of rat intestinal epithelial cells in a dose- and time-dependent manner. Polaprezinc significantly suppressed acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells at its late phase. At the same time, polaprezinc increased Heat shock protein 70 expressions of rat intestinal epithelial cells in a time-dependent manner. However, in Heat shock protein 70-silenced rat intestinal epithelial cells, polaprezinc could not suppress acetylsalicylic acid -induced apoptosis at its late phase. We conclude that polaprezinc-increased Heat shock protein 70 expression might be an important mechanism by which polaprezinc suppresses acetylsalicylic

  8. Rapid Formation of Cell Aggregates and Spheroids Induced by a "Smart" Boronic Acid Copolymer.

    PubMed

    Amaral, Adérito J R; Pasparakis, George

    2016-09-01

    Cell surface engineering has emerged as a powerful approach to forming cell aggregates/spheroids and cell-biomaterial ensembles with significant uses in tissue engineering and cell therapeutics. Herein, we demonstrate that cell membrane remodeling with a thermoresponsive boronic acid copolymer induces the rapid formation of spheroids using either cancer or cardiac cell lines under conventional cell culture conditions at minute concentrations. It is shown that the formation of well-defined spheroids is accelerated by at least 24 h compared to non-polymer-treated controls, and, more importantly, the polymer allows for fine control of the aggregation kinetics owing to its stimulus response to temperature and glucose content. On the basis of its simplicity and effectiveness to promote cellular aggregation, this platform holds promise in three-dimensional tissue/tumor modeling and tissue engineering applications. PMID:27571512

  9. Ethylene signaling in salt stress- and salicylic acid-induced programmed cell death in tomato suspension cells.

    PubMed

    Poór, Péter; Kovács, Judit; Szopkó, Dóra; Tari, Irma

    2013-02-01

    Salt stress- and salicylic acid (SA)-induced cell death can be activated by various signaling pathways including ethylene (ET) signaling in intact tomato plants. In tomato suspension cultures, a treatment with 250 mM NaCl increased the production of reactive oxygen species (ROS), nitric oxide (NO), and ET. The 10(-3) M SA-induced cell death was also accompanied by ROS and NO production, but ET emanation, the most characteristic difference between the two cell death programs, did not change. ET synthesis was enhanced by addition of ET precursor 1-aminocyclopropane-1-carboxylic acid, which, after 2 h, increased the ROS production in the case of both stressors and accelerated cell death under salt stress. However, it did not change the viability and NO levels in SA-treated samples. The effect of ET induced by salt stress could be blocked with silver thiosulfate (STS), an inhibitor of ET action. STS reduced the death of cells which is in accordance with the decrease in ROS production of cells exposed to high salinity. Unexpectedly, application of STS together with SA resulted in increasing ROS and reduced NO accumulation which led to a faster cell death. NaCl- and SA-induced cell death was blocked by Ca(2+) chelator EGTA and calmodulin inhibitor W-7, or with the inhibitors of ROS. The inhibitor of MAPKs, PD98059, and the cysteine protease inhibitor E-64 reduced cell death in both cases. These results show that NaCl induces cell death mainly by ET-induced ROS production, but ROS generated by SA was not controlled by ET in tomato cell suspension. PMID:22535239

  10. Valeric acid induces cell cycle arrest at G1 phase in CHO cell cultures and improves recombinant antibody productivity.

    PubMed

    Park, Jin Hyoung; Noh, Soo Min; Woo, Ju Rang; Kim, Jong Won; Lee, Gyun Min

    2016-03-01

    To find a more effective chemical reagent for improved monoclonal antibody (mAb) production, eight chemical reagents (curcumin, quercein, DL-sulforaphane, thymidine, valeric acid, phenyl butyrate, valproic acid, and lithium chloride) known to induce cell cycle arrest were examined individually as chemical additives to recombinant CHO (rCHO) cell cultures producing mAb. Among these chemical additives, valeric acid showed the best production performance. Valeric acid decreased specific growth rate (μ), but increased culture longevity and specific mAb productivity (qmAb ) in a dose-dependent manner. The beneficial effect of valeric acid on culture longevity and qmAb outweighed its detrimental effect on μ, resulting in 2.9-fold increase in the maximum mAb concentration when 1.5 mM valeric acid was added to the cultures. Furthermore, valeric acid did not negatively affect the mAb quality attributes with regard to aggregation, charge variation, and galactosylation. Unexpectedly, galactosylation of the mAb increased by the 1.5 mM valeric acid addition. Taken together, the results obtained here demonstrate that valeric acid is an effective chemical reagent to increase mAb production in rCHO cells. PMID:26663903

  11. Protective Effect of Edaravone in Primary Cerebellar Granule Neurons against Iodoacetic Acid-Induced Cell Injury

    PubMed Central

    Zhou, Xinhua; Zhu, Longjun; Wang, Liang; Guo, Baojian; Zhang, Gaoxiao; Sun, Yewei; Zhang, Zaijun; Lee, Simon Ming-Yuen; Yu, Pei; Wang, Yuqiang

    2015-01-01

    Edaravone (EDA) is clinically used for treatment of acute ischemic stroke in Japan and China due to its potent free radical-scavenging effect. However, it has yet to be determined whether EDA can attenuate iodoacetic acid- (IAA-) induced neuronal death in vitro. In the present study, we investigated the effect of EDA on damage of IAA-induced primary cerebellar granule neurons (CGNs) and its possible underlying mechanisms. We found that EDA attenuated IAA-induced cell injury in CGNs. Moreover, EDA significantly reduced intracellular reactive oxidative stress production, loss of mitochondrial membrane potential, and caspase 3 activity induced by IAA. Taken together, EDA protected CGNs against IAA-induced neuronal damage, which may be attributed to its antiapoptotic and antioxidative activities. PMID:26557222

  12. C. butyricum lipoteichoic acid inhibits the inflammatory response and apoptosis in HT-29 cells induced by S. aureus lipoteichoic acid.

    PubMed

    Wang, Jinbo; Qi, Lili; Mei, Lehe; Wu, Zhige; Wang, Hengzheng

    2016-07-01

    Lipoteichoic acid (LTA) is one of microbe-associated molecular pattern (MAMP) molecules of gram-positive bacteria. In this study, we demonstrated that Clostridium butyricum LTA (bLTA) significantly inhibited the inflammatory response and apoptosis induced by Staphylococcus aureus LTA (aLTA) in HT-29 cells. aLTA stimulated the inflammatory responses by activating a strong signal transduction cascade through NF-κB and ERK, but bLTA did not activate the signaling pathway. bLTA pretreatment inhibited the activation of the NF-κB and ERK signaling pathway induced by aLTA. The expression and release of cytokines such as IL-8 and TNF-α were also suppressed by bLTA pretreatment. aLTA treatment induced apoptosis in HT-29 cells, but bLTA did not affect the viability of the cells. Further study indicated that bLTA inhibited apoptosis in HT-29 cells induced by aLTA. These results suggest that bLTA may act as an aLTA antagonist and that an antagonistic bLTA may be a useful agent for suppressing the pro-inflammatory activities of gram-positive pathogenic bacteria. PMID:27020942

  13. Dasatinib accelerates valproic acid-induced acute myeloid leukemia cell death by regulation of differentiation capacity.

    PubMed

    Heo, Sook-Kyoung; Noh, Eui-Kyu; Yoon, Dong-Joon; Jo, Jae-Cheol; Park, Jae-Hoo; Kim, Hawk

    2014-01-01

    Dasatinib is a compound developed for chronic myeloid leukemia as a multi-targeted kinase inhibitor against wild-type BCR-ABL and SRC family kinases. Valproic acid (VPA) is an anti-epileptic drug that also acts as a class I histone deacetylase inhibitor. The aim of this research was to determine the anti-leukemic effects of dasatinib and VPA in combination and to identify their mechanism of action in acute myeloid leukemia (AML) cells. Dasatinib was found to exert potent synergistic inhibitory effects on VPA-treated AML cells in association with G1 phase cell cycle arrest and apoptosis induction involving the cleavage of poly (ADP-ribose) polymerase and caspase-3, -7 and -9. Dasatinib/VPA-induced cell death thus occurred via caspase-dependent apoptosis. Moreover, MEK/ERK and p38 MAPK inhibitors efficiently inhibited dasatinib/VPA-induced apoptosis. The combined effect of dasatinib and VPA on the differentiation capacity of AML cells was more powerful than the effect of each drug alone, being sufficiently strong to promote AML cell death through G1 cell cycle arrest and caspase-dependent apoptosis. MEK/ERK and p38 MAPK were found to control dasatinib/VPA-induced apoptosis as upstream regulators, and co-treatment with dasatinib and VPA to contribute to AML cell death through the regulation of differentiation capacity. Taken together, these results indicate that combined dasatinib and VPA treatment has a potential role in anti-leukemic therapy. PMID:24918603

  14. Mast cell mediators in citric acid-induced airway constriction of guinea pigs

    SciTech Connect

    Lin, C.-H.; Lai, Y.-L. . E-mail: tiger@ha.mc.ntu.edu.tw

    2005-08-15

    We demonstrated previously that mast cells play an important role in citric acid (CA)-induced airway constriction. In this study, we further investigated the underlying mediator(s) for this type of airway constriction. At first, to examine effects caused by blocking agents, 67 young Hartley guinea pigs were divided into 7 groups: saline + CA; methysergide (serotonin receptor antagonist) + CA; MK-886 (leukotriene synthesis inhibitor) + CA; mepyramine (histamine H{sub 1} receptor antagonist) + CA; indomethacin (cyclooxygenase inhibitor) + CA; cromolyn sodium (mast cell stabilizer) + CA; and compound 48/80 (mast cell degranulating agent) + CA. Then, we tested whether leukotriene C{sub 4} (LTC{sub 4}) or histamine enhances CA-induced airway constriction in compound 48/80-pretreated guinea pigs. We measured dynamic respiratory compliance (Crs) and forced expiratory volume in 0.1 s (FEV{sub 0.1}) during either baseline or recovery period. In addition, we detected histamine level, an index of pulmonary mast cell degranulation, in bronchoalveolar lavage (BAL) samples. Citric acid aerosol inhalation caused decreases in Crs and FEV{sub 0.1}, indicating airway constriction in the control group. This airway constriction was significantly attenuated by MK-886, mepyramine, cromolyn sodium, and compound 48/80, but not by either methysergide or indomethacin. Both LTC{sub 4} and histamine infusion significantly increased the magnitude of CA-induced airway constriction in compound 48/80-pretreated guinea pigs. Citric acid inhalation caused significant increase in histamine level in the BAL sample, which was significantly suppressed by compound 48/80. These results suggest that leukotrienes and histamine originating from mast cells play an important role in CA inhalation-induced noncholinergic airway constriction.

  15. Free fatty acids block glucose-induced β-cell proliferation in mice by inducing cell cycle inhibitors p16 and p18.

    PubMed

    Pascoe, Jordan; Hollern, Douglas; Stamateris, Rachel; Abbasi, Munira; Romano, Lia C; Zou, Baobo; O'Donnell, Christopher P; Garcia-Ocana, Adolfo; Alonso, Laura C

    2012-03-01

    Pancreatic β-cell proliferation is infrequent in adult humans and is not increased in type 2 diabetes despite obesity and insulin resistance, suggesting the existence of inhibitory factors. Free fatty acids (FFAs) may influence proliferation. In order to test whether FFAs restrict β-cell proliferation in vivo, mice were intravenously infused with saline, Liposyn II, glucose, or both, continuously for 4 days. Lipid infusion did not alter basal β-cell proliferation, but blocked glucose-stimulated proliferation, without inducing excess β-cell death. In vitro exposure to FFAs inhibited proliferation in both primary mouse β-cells and in rat insulinoma (INS-1) cells, indicating a direct effect on β-cells. Two of the fatty acids present in Liposyn II, linoleic acid and palmitic acid, both reduced proliferation. FFAs did not interfere with cyclin D2 induction or nuclear localization by glucose, but increased expression of inhibitor of cyclin dependent kinase 4 (INK4) family cell cycle inhibitors p16 and p18. Knockdown of either p16 or p18 rescued the antiproliferative effect of FFAs. These data provide evidence for a novel antiproliferative form of β-cell glucolipotoxicity: FFAs restrain glucose-stimulated β-cell proliferation in vivo and in vitro through cell cycle inhibitors p16 and p18. If FFAs reduce proliferation induced by obesity and insulin resistance, targeting this pathway may lead to new treatment approaches to prevent diabetes. PMID:22338094

  16. Mast cells in citric acid-induced cough of guinea pigs

    SciTech Connect

    Lai, Y.-L. . E-mail: tiger@ha.mc.ntu.edu.tw; Lin, T.-Y.

    2005-01-01

    It was demonstrated previously that mast cells play an important role in citric acid (CA)-induced airway constriction. To investigate the role of mast cells in CA-induced cough, three experiments were carried out in this study. In the first experiment, 59 guinea pigs were employed and we used compound 48/80 to deplete mast cells, cromolyn sodium to stabilize mast cells, MK-886 to inhibit leukotriene synthesis, pyrilamine to antagonize histamine H{sub 1} receptor, methysergide to antagonize serotonin receptor, and indomethacin to inhibit cyclooxygenase. In the second experiment, 56 compound 48/80-pretreated animals were divided into two parts; the first one was used to test the role of exogenous leukotriene (LT) C{sub 4}, while the second one to test the role of exogenous histamine in CA-induced cough. Each animal with one of the above pretreatments was exposed sequentially to saline (baseline) and CA (0.6 M) aerosol, each for 3 min. Then, cough was recorded for 12 min using a barometric body plethysmograph. In the third experiment, the activation of mast cells upon CA inhalation was investigated by determining arterial plasma histamine concentration in 17 animals. Exposure to CA induced a marked increase in cough number. Compound 48/80, cromolyn sodium, MK-886 and pyrilamine, but not indomethacin or methysergide, significantly attenuated CA-induced cough. Injection of LTC{sub 4} or histamine caused a significant increase in CA-induced cough in compound 48/80-pretreated animals. In addition, CA inhalation caused significant increase in plasma histamine concentration, which was blocked by compound 48/80 pretreatment. These results suggest that mast cells play an important role in CA aerosol inhalation-induced cough via perhaps mediators LTs and histamine.

  17. Regulation of acid phosphatase activity in human promyelocytic leukemic cells induced to differentiate in culture

    PubMed Central

    1979-01-01

    Induction of differentiation of a human promyelocytic leukemic cell line (HL60) in culture is accompanied by changes in acid phosphatase (Acpase) activity. The increase in activity is less than twofold when the leukemic cells are stimulated by dimethylsulfoxide (DMSO) to differentiate into metamyelocytes and granulocytes but is eightfold when the cells are stimulated by the tumor-promoting agent 12-0- tetradecanoylphorbol 13-acetate (TPA) to differentiate into macrophage- like cells. Five different isozymes of Acpase were separated by acrylamide gel electrophoresis. Isozyme 1, the most anodal isozyme, was found to be present in undifferentiated, DMSO-treated and TPA-treated cells; isozyme 2 was a very faint band observed both in DMSO- and TPA- treated cells, the isoenzymes 3a and 3b were present only in TPA- induced cells; and isozyme 4, the most cathodal isozyme, was present both in TPA- and DMSO-induced cells. A time sequence study on the appearance of the various forms after TPA treatment indicated that the expression of the isozymes is regulated in an uncoordinated fashion. Acpase activity has been shown by ultrastructural cytochemistry to be localized in the entire rough endoplasmic reticulum (RER) and in areas of the smooth endoplasmic reticulum (SER) located near the Golgi complex in differentiating cells but to be extremely weak, if at all detectable, in undifferentiated promyelocytes. PMID:291600

  18. Dehydroabietic Acid Derivative QC4 Induces Gastric Cancer Cell Death via Oncosis and Apoptosis

    PubMed Central

    Luo, Dongjun; Ni, Qing; Ji, Anlai; Gu, Wen; Wu, Junhua

    2016-01-01

    Aim. QC4 is the derivative of rosin's main components dehydroabietic acid (DHA). We investigated the cytotoxic effect of QC4 on gastric cancer cells and revealed the mechanisms beneath the induction of cell death. Methods. The cytotoxic effect of QC4 on gastric cancer cells was evaluated by CCK-8 assay and flow cytometry. The underlying mechanisms were tested by administration of cell death related inhibitors and detection of apoptotic and oncosis related proteins. Cytomembrane integrity and organelles damage were confirmed by lactate dehydrogenase (LDH) leakage assay, mitochondrial function test, and cytosolic free Ca2+ concentration detection. Results. QC4 inhibited cell proliferation dose- and time-dependently and destroyed cell membrane integrity, activated calpain-1 autolysis, and induced apoptotic protein cleavage in gastric cancer cells. The detection of decreased ATP and mitochondrial membrane potential, ROS accumulation, and cytosolic free Ca2+ elevation confirmed organelles damage in QC4-treated gastric cancer cells. Conclusions. DHA derivative QC4 induced the damage of cytomembrane and organelles which finally lead to oncosis and apoptosis in gastric cancer cells. Therefore, as a derivative of plant derived small molecule DHA, QC4 might become a promising agent in gastric cancer therapy. PMID:27057539

  19. Curcumin and docosahexaenoic acid block insulin-induced colon carcinoma cell proliferation.

    PubMed

    Fenton, Jenifer I; McCaskey, Sarah J

    2013-03-01

    Diets high in fish and curcumin are associated with a decreased risk of CRC. Insulin resistance and obesity are associated with increased CRC risk and higher reoccurrence rates. We utilized cell culture to determine if dietary compounds could reduce insulin-induced cell proliferation comparing the response in normal and metastatic colon epithelial cells. We treated model normal murine colon epithelial cells (YAMC) and adenocarcinoma cells (MC38) with docosahexaenoic acid (DHA) or curcumin alone and then co-treatments of the diet-derived compound and insulin were combined. Cell proliferation was stimulated with insulin (1 ug/mL) to model insulin resistance in obesity. Despite the presence of insulin, proliferation was reduced in the MC38 cells treated with 10 μM curcumin (p<0.001) and 50 μM DHA (p<0.001). Insulin stimulated MAPK and MEK phosphorylation was inhibited by DHA and curcumin in MC38 cancer cells. Here we show that curcumin and DHA can block insulin-induced colon cancer cell proliferation in vitro via a MEK mediated mechanism. PMID:23266210

  20. Green tea polyphenol epigallocatechin-O-gallate induces cell death by acid sphingomyelinase activation in chronic myeloid leukemia cells.

    PubMed

    Huang, Yuhui; Kumazoe, Motofumi; Bae, Jaehoon; Yamada, Shuhei; Takai, Mika; Hidaka, Shiori; Yamashita, Shuya; Kim, Yoonhee; Won, Yeongseon; Murata, Motoki; Tsukamoto, Shuntaro; Tachibana, Hirofumi

    2015-09-01

    An epidemiological study showed that green tea consumption is associated with a reduced risk of hematopoietic malignancy. The major green tea polyphenol epigallocatechin‑3-O-gallate (EGCG) is reported to have anticancer effects. Chronic myeloid leukemia (CML) is a major hematopoietic malignancy characterized by expansion of myeloid cells. In the present study, we showed EGCG-induced acid sphingomyelinase (ASM) activation and lipid raft clustering in CML cells. The ASM inhibitor desipramine significantly reduced EGCG-induced cell death. Protein kinase Cδ is a well‑known kinase that plays an important role in ASM activation. We observed EGCG-induced phosphorylation of protein kinase Cδ at Ser664. Importantly, EGCG-induced ASM activation was significantly reduced by pretreatment of CML cells with the soluble guanylate cyclase inhibitor NS2028, suggesting that EGCG induced ASM activation through the cyclic guanosine monophosphate (cGMP)-dependent pathway. Indeed, pharmacological inhibition of a cGMP-negative regulator enhanced the anti-CML effect of EGCG. These results indicate that EGCG-induced cell death via the cGMP/ASM pathway in CML cells. PMID:26135316

  1. Green tea polyphenol epigallocatechin-O-gallate induces cell death by acid sphingomyelinase activation in chronic myeloid leukemia cells

    PubMed Central

    HUANG, YUHUI; KUMAZOE, MOTOFUMI; BAE, JAEHOON; YAMADA, SHUHEI; TAKAI, MIKA; HIDAKA, SHIORI; YAMASHITA, SHUYA; KIM, YOONHEE; WON, YEONGSEON; MURATA, MOTOKI; TSUKAMOTO, SHUNTARO; TACHIBANA, HIROFUMI

    2015-01-01

    An epidemiological study showed that green tea consumption is associated with a reduced risk of hematopoietic malignancy. The major green tea polyphenol epigallocatechin-3-O-gallate (EGCG) is reported to have anticancer effects. Chronic myeloid leukemia (CML) is a major hematopoietic malignancy characterized by expansion of myeloid cells. In the present study, we showed EGCG-induced acid sphingomyelinase (ASM) activation and lipid raft clustering in CML cells. The ASM inhibitor desipramine significantly reduced EGCG-induced cell death. Protein kinase Cδ is a well-known kinase that plays an important role in ASM activation. We observed EGCG-induced phos-phorylation of protein kinase Cδ at Ser664. Importantly, EGCG-induced ASM activation was significantly reduced by pretreatment of CML cells with the soluble guanylate cyclase inhibitor NS2028, suggesting that EGCG induced ASM activation through the cyclic guanosine monophosphate (cGMP)-dependent pathway. Indeed, pharmacological inhibition of a cGMP-negative regulator enhanced the anti-CML effect of EGCG. These results indicate that EGCG-induced cell death via the cGMP/ASM pathway in CML cells. PMID:26135316

  2. Gallic acid induced apoptotic events in HCT-15 colon cancer cells

    PubMed Central

    Subramanian, Aruna Priyadharshni; Jaganathan, Saravana Kumar; Mandal, Mahitosh; Supriyanto, Eko; Muhamad, Ida Idayu

    2016-01-01

    AIM: To investigate the inhibitory action of diet-derived phenolic compound gallic acid (GA) against HCT-15 colon cancer cells. METHODS: The antiproliferative effect of GA against colon cancer cells was determined by performing thiazolyl blue tetrazolium bromide (MTT) assay. The colony forming ability of GA treated colon cancer cells was evaluated using the colony forming assay. The cell cycle changes induced by GA in HCT-15 cells were analyzed by propidium iodide staining. Levels of reactive oxygen species (ROS) and mitochondrial membrane potential of HCT-15 exposed to GA was assessed using 2’,7’-dichlorfluorescein-diacetate and rhodamine-123 respectively, with the help of flow cytometry. Morphological changes caused by GA treatment in the colon cancer cells were identified by scanning electron microscope and photomicrograph examination. Apoptosis was confirmed using flow cytometric analysis of GA treated HCT-15 cells after staining with Yo-Pro-1. RESULTS: MTT assay results illustrated that GA has an inhibitory effect on HCT-15 cells with IC50 value of 740 μmol/L. A time-dependent inhibition of colony formation was evident with GA treatment. Cell cycle arrest was evident from the accumulation of GA treated HCT-15 cells at sub-G1 phase (0.98 ± 1.03 vs 58.01 ± 2.05) with increasing exposure time. Flow cytometric analysis of GA treated HCT-15 cells depicted early events associated with apoptosis like lipid layer breakage and fall in mitochondrial membrane potential apart from an increase in the generation of ROS which were in a time dependent manner. SEM and photomicrograph images of the GA-treated cells displayed membrane blebbing and cell shrinking characteristics of apoptosis. Further apoptosis confirmation by Yo-Pro-1 staining also showed the time-dependent increase of apoptotic cells after treatment. CONCLUSION: These results show that GA induced ROS dependent apoptosis and inhibited the growth of colon cancer cells. PMID:27099438

  3. Gambogic acid inhibits growth, induces apoptosis, and overcomes drug resistance in human colorectal cancer cells.

    PubMed

    Wen, Chuangyu; Huang, Lanlan; Chen, Junxiong; Lin, Mengmeng; Li, Wen; Lu, Biyan; Rutnam, Zina Jeyapalan; Iwamoto, Aikichi; Wang, Zhongyang; Yang, Xiangling; Liu, Huanliang

    2015-11-01

    The emergence of chemoresistance is a major limitation of colorectal cancer (CRC) therapies and novel biologically based therapies are urgently needed. Natural products represent a novel potential anticancer therapy. Gambogic acid (GA), a small molecule derived from Garcinia hanburyi Hook. f., has been demonstrated to be highly cytotoxic to several types of cancer cells and have low toxicity to the hematopoietic system. However, the potential role of GA in colorectal cancer and its ability to overcome the chemotherapeutic resistance in CRC cells have not been well studied. In the present study, we showed that GA directly inhibited proliferation and induced apoptosis in both 5-fluorouracil (5-FU) sensitive and 5-FU resistant colorectal cancer cells; induced apoptosis via activating JNK signaling pathway. The data, therefore, suggested an alternative strategy to overcome 5-FU resistance in CRC and that GA could be a promising medicinal compound for colorectal cancer therapy. PMID:26397804

  4. Gambogic acid inhibits growth, induces apoptosis, and overcomes drug resistance in human colorectal cancer cells

    PubMed Central

    WEN, CHUANGYU; HUANG, LANLAN; CHEN, JUNXIONG; LIN, MENGMENG; LI, WEN; LU, BIYAN; RUTNAM, ZINA JEYAPALAN; IWAMOTO, AIKICHI; WANG, ZHONGYANG; YANG, XIANGLING; LIU, HUANLIANG

    2015-01-01

    The emergence of chemoresistance is a major limitation of colorectal cancer (CRC) therapies and novel biologically based therapies are urgently needed. Natural products represent a novel potential anticancer therapy. Gambogic acid (GA), a small molecule derived from Garcinia hanburyi Hook. f., has been demonstrated to be highly cytotoxic to several types of cancer cells and have low toxicity to the hematopoietic system. However, the potential role of GA in colorectal cancer and its ability to overcome the chemotherapeutic resistance in CRC cells have not been well studied. In the present study, we showed that GA directly inhibited proliferation and induced apoptosis in both 5-fluorouracil (5-FU) sensitive and 5-FU resistant colorectal cancer cells; induced apoptosis via activating JNK signaling pathway. The data, therefore, suggested an alternative strategy to overcome 5-FU resistance in CRC and that GA could be a promising medicinal compound for colorectal cancer therapy. PMID:26397804

  5. Physiological concentrations of bile acids down-regulate agonist induced secretion in colonic epithelial cells.

    PubMed

    Keating, Niamh; Mroz, Magdalena S; Scharl, Michael M; Marsh, Christine; Ferguson, Gail; Hofmann, Alan F; Keely, Stephen J

    2009-08-01

    In patients with bile acid malabsorption, high concentrations of bile acids enter the colon and stimulate Cl(-) and fluid secretion, thereby causing diarrhoea. However, deoxycholic acid (DCA), the predominant colonic bile acid, is normally present at lower concentrations where its role in regulating transport is unclear. Thus, the current study set out to investigate the effects of physiologically relevant DCA concentrations on colonic epithelial secretory function. Cl(-) secretion was measured as changes in short-circuit current across voltage-clamped T(84) cell monolayers. At high concentrations (0.5-1 mM), DCA acutely stimulated Cl(-) secretion but this effect was associated with cell injury, as evidenced by decreased transepithelial resistance (TER) and increased lactate dehydrogenase (LDH) release. In contrast, chronic (24 hrs) exposure to lower DCA concentrations (10-200 microM) inhibited responses to Ca(2+) and cAMP-dependent secretagogues without altering TER, LDH release, or secretagogue-induced increases in intracellular second messengers. Other bile acids - taurodeoxycholic acid, chenodeoxycholic acid and cholic acid - had similar antisecretory effects. DCA (50 microM) rapidly stimulated phosphorylation of the epidermal growth factor receptor (EGFr) and both ERK and p38 MAPKs (mitogen-activated protein kinases). The EGFr inhibitor, AG1478, and the protein synthesis inhibitor, cycloheximide, reversed the antisecretory effects of DCA, while the MAPK inhibitors, PD98059 and SB203580, did not. In summary, our studies suggest that, in contrast to its acute prosecretory effects at pathophysiological concentrations, lower, physiologically relevant, levels of DCA chronically down-regulate colonic epithelial secretory function. On the basis of these data, we propose a novel role for bile acids as physiological regulators of colonic secretory capacity. PMID:19583809

  6. Physiological concentrations of bile acids down‐regulate agonist induced secretion in colonic epithelial cells

    PubMed Central

    Keating, Niamh; Mroz, Magdalena S.; Scharl, Michael M.; Marsh, Christine; Ferguson, Gail; Hofmann, Alan F.

    2009-01-01

    Abstract In patients with bile acid malabsorption, high concentrations of bile acids enter the colon and stimulate Cl− and fluid secretion, thereby causing diarrhoea. However, deoxycholic acid (DCA), the predominant colonic bile acid, is normally present at lower concentrations where its role in regulating transport is unclear. Thus, the current study set out to investigate the effects of physiologically relevant DCA concentrations on colonic epithelial secretory function. Cl− secretion was measured as changes in short‐circuit current across voltage‐clamped T84 cell monolayers. At high concentrations (0.5–1 mM), DCA acutely stimulated Cl− secretion but this effect was associated with cell injury, as evidenced by decreased transepithelial resistance (TER) and increased lactate dehydrogenase (LDH) release. In contrast, chronic (24 hrs) exposure to lower DCA concentrations (10–200 μM) inhibited responses to Ca2+ and cAMP‐dependent secretagogues without altering TER, LDH release, or secretagogue‐induced increases in intracellular second messengers. Other bile acids – taurodeoxycholic acid, chenodeoxycholic acid and cholic acid – had similar antisecretory effects. DCA (50 μM) rapidly stimulated phosphorylation of the epidermal growth factor receptor (EGFr) and both ERK and p38 MAPKs (mitogen‐activated protein kinases). The EGFr inhibitor, AG1478, and the protein synthesis inhibitor, cycloheximide, reversed the antisecretory effects of DCA, while the MAPK inhibitors, PD98059 and SB203580, did not. In summary, our studies suggest that, in contrast to its acute prosecretory effects at pathophysiological concentrations, lower, physiologically relevant, levels of DCA chronically down‐regulate colonic epithelial secretory function. On the basis of these data, we propose a novel role for bile acids as physiological regulators of colonic secretory capacity. PMID:19583809

  7. Fatty Acid Esters of Phloridzin Induce Apoptosis of Human Liver Cancer Cells through Altered Gene Expression

    PubMed Central

    Nair, Sandhya V. G.; Ziaullah; Rupasinghe, H. P. Vasantha

    2014-01-01

    Phloridzin (phlorizin or phloretin 2′-O-glucoside) is known for blocking intestinal glucose absorption. We have investigated the anticarcinogenic effect of phloridzin and its novel derivatives using human cancer cell lines. We have synthesised novel acylated derivatives of phloridzin with six different long chain fatty acids by regioselective enzymatic acylation using Candida Antarctica lipase B. The antiproliferative effects of the new compounds were investigated in comparison with the parent compounds, phloridzin, aglycone phloretin, the six free fatty acids and chemotherapeutic drugs (sorafenib, doxorubicin and daunorubicin) using human hepatocellular carcinoma HepG2 cells, human breast adenocarcinoma MDA-MB-231 cells and acute monocytic leukemia THP-1 cells along with normal human and rat hepatocytes. The fatty acid esters of phloridzin inhibited significantly the growth of the two carcinoma and leukemia cells while similar treatment doses were not toxic to normal human or rat hepatocytes. The antiproliferative potency of fatty esters of phloridzin was comparable to the potency of the chemotherapeutic drugs. The fatty acid esters of phloridzin inhibited DNA topoisomerases IIα activity that might induce G0/G1 phase arrest, induced apoptosis via activation of caspase-3, and decreased ATP level and mitochondrial membrane potential in HepG2 cells. Based on the high selectivity on cancer cells, decosahexaenoic acid (DHA) ester of phloridzin was selected for gene expression analysis using RT2PCR human cancer drug target array. Antiproliferative effect of DHA ester of phloridzin could be related to the down regulation of anti-apoptotic gene (BCL2), growth factor receptors (EBFR family, IGF1R/IGF2, PDGFR) and its downstream signalling partners (PI3k/AKT/mTOR, Ras/Raf/MAPK), cell cycle machinery (CDKs, TERT, TOP2A, TOP2B) as well as epigenetics regulators (HDACs). These results suggest that fatty esters of phloridzin have potential chemotherapeutic effects mediated

  8. The AhR agonist VAF347 augments retinoic acid-induced differentiation in leukemia cells.

    PubMed

    Ibabao, Christopher N; Bunaciu, Rodica P; Schaefer, Deanna M W; Yen, Andrew

    2015-01-01

    In binary cell-fate decisions, driving one lineage and suppressing the other are conjoined. We have previously reported that aryl hydrocarbon receptor (AhR) promotes retinoic acid (RA)-induced granulocytic differentiation of lineage bipotent HL-60 myeloblastic leukemia cells. VAF347, an AhR agonist, impairs the development of CD14(+)CD11b(+) monocytes from granulo-monocytic (GM) stage precursors. We thus hypothesized that VAF347 propels RA-induced granulocytic differentiation and impairs D3-induced monocytic differentiation of HL-60 cells. Our results show that VAF347 enhanced RA-induced cell cycle arrest, CD11b integrin expression and neutrophil respiratory burst. Granulocytic differentiation is known to be driven by MAPK signaling events regulated by Fgr and Lyn Src-family kinases, the CD38 cell membrane receptor, the Vav1 GEF, the c-Cbl adaptor, as well as AhR, all of which are embodied in a putative signalsome. We found that the VAF347 AhR ligand regulates the signalsome. VAF347 augments RA-induced expression of AhR, Lyn, Vav1, and c-Cbl as well as p47(phox). Several interactions of partners in the signalsome appear to be enhanced: Fgr interaction with c-Cbl, CD38, and with pS259c-Raf and AhR interaction with c-Cbl and Lyn. Thus, we report that, while VAF347 impedes monocytic differentiation induced by 1,25-dihydroxyvitamin D3, VAF347 promotes RA-induced differentiation. This effect seems to involve but not to be limited to Lyn, Vav1, c-Cbl, AhR, and Fgr. PMID:25941627

  9. Early membrane events induced by salicylic acid in motor cells of the Mimosa pudica pulvinus.

    PubMed

    Saeedi, Saed; Rocher, Françoise; Bonmort, Janine; Fleurat-Lessard, Pierrette; Roblin, Gabriel

    2013-04-01

    Salicylic acid (o-hydroxy benzoic acid) (SA) induced a rapid dose-dependent membrane hyperpolarization (within seconds) and a modification of the proton secretion (within minutes) of Mimosa pudica pulvinar cells at concentrations higher than 0.1mM. Observations on plasma membrane vesicles isolated from pulvinar tissues showed that SA acted directly at the membrane level through a protonophore action as suggested by the inhibition of the proton gradient and the lack of effect on H(+)-ATPase catalytic activity. Comparative data obtained with protonophores (carbonylcyanide-m-chlorophenylhydrazone and 2,4-dinitrophenol) and inhibitors of ATPases (vanadate, N,N'-dicyclohexylcarbodiimide, and diethylstilbestrol) corroborated this conclusion. Consequently, the collapse of the proton motive force led to an impairment in membrane functioning. This impairment is illustrated by the inhibition of the ion-driven turgor-mediated seismonastic reaction of the pulvinus following SA treatment. SA acted in a specific manner as its biosynthetic precursor benzoic acid induced much milder effects and the m- and p-OH benzoic acid derivatives did not trigger similar characteristic effects. Therefore, SA may be considered both a membrane signal molecule and a metabolic effector following its uptake in the cells. PMID:23487303

  10. Wnt signaling pathway participates in valproic acid-induced neuronal differentiation of neural stem cells

    PubMed Central

    Wang, Li; Liu, Yuan; Li, Sen; Long, Zai-Yun; Wu, Ya-Min

    2015-01-01

    Neural stem cells (NSCs) are multipotent cells that have the capacity for differentiation into the major cell types of the nervous system, i.e. neurons, astrocytes and oligodendrocytes. Valproic acid (VPA) is a widely prescribed drug for seizures and bipolar disorder in clinic. Previously, a number of researches have been shown that VPA has differential effects on growth, proliferation and differentiation in many types of cells. However, whether VPA can induce NSCs from embryonic cerebral cortex differentiate into neurons and its possible molecular mechanism is also not clear. Wnt signaling is implicated in the control of cell growth and differentiation during CNS development in animal model, but its action at the cellular level has been poorly understood. In this experiment, we examined neuronal differentiation of NSCs induced by VPA culture media using vitro immunochemistry assay. The neuronal differentiation of NSCs was examined after treated with 0.75 mM VPA for three, seven and ten days. RT-PCR assay was employed to examine the level of Wnt-3α and β-catenin. The results indicated that there were more β-tublin III positive cells in NSCs treated with VPA medium compared to the control group. The expression of Wnt-3α and β-catenin in NSCs treated with VPA medium was significantly greater compared to that of control media. In conclusion, these findings indicated that VPA could induce neuronal differentiation of NSCs by activating Wnt signal pathway. PMID:25755748

  11. Pathway of cytotoxicity induced by folic acid modified selenium nanoparticles in MCF-7 cells.

    PubMed

    Pi, Jiang; Jin, Hua; Liu, Ruiying; Song, Bing; Wu, Qing; Liu, Li; Jiang, Jinhuan; Yang, Fen; Cai, Huaihong; Cai, Jiye

    2013-02-01

    Selenium nanoparticles (Se NPs) have been recognized as promising materials for biomedical applications. To prepare Se NPs which contained cancer targeting methods and to clarify the cellular localization and cytotoxicity mechanisms of these Se NPs against cancer cells, folic acid protected/modified selenium nanoparticles (FA-Se NPs) were first prepared by a one-step method. Some morphologic and spectroscopic methods were obtained to prove the successfully formation of FA-Se NPs while free folate competitive inhibition assay, microscope, and several biological methods were used to determine the in vitro uptake, subcellular localization, and cytotoxicity mechanism of FA-Se NPs in MCF-7 cells. The results indicated that the 70-nm FA-Se NPs were internalized by MCF-7 cells through folate receptor-mediated endocytosis and targeted to mitochondria located regions through endocytic vesicles transporting. Then, the FA-Se NPs entered into mitochondria; triggered the mitochondria-dependent apoptosis of MCF-7 cells which involved oxidative stress, Ca(2)+ stress changes, and mitochondrial dysfunction; and finally caused the damage of mitochondria. FA-Se NPs released from broken mitochondria were transported into nucleus and further into nucleolus which then induced MCF-7 cell cycle arrest. In addition, FA-Se NPs could induce cytoskeleton disorganization and induce MCF-7 cell membrane morphology alterations. These results collectively suggested that FA-Se NPs could be served as potential therapeutic agents and organelle-targeted drug carriers in cancer therapy. PMID:22945264

  12. Acanthoic acid inhibits LPS-induced inflammatory response by activating LXRα in human umbilical vein endothelial cells.

    PubMed

    Li, Yong; Zhang, Xiao-Shi; Yu, Jin-Long

    2016-03-01

    Acanthoic acid, a pimaradiene diterpene isolated from Acanthopanax koreanum, has been reported to have anti-inflammatory activities. However, the effect of acanthoic acid on vascular inflammation has not been investigated. The aim of this study was to investigate the anti-inflammatory effects of acanthoic acid on lipopolysaccharide (LPS)-induced inflammatory response in human umbilical vein endothelial cells (HUVECs). The production of cytokines TNF-α and IL-8 was detected by ELISA. The expression of VCAM-1, ICAM-1, E-selectin, NF-κB and LXRα were detected by Western blotting. Adhesion of monocytes to HUVECs was detected by monocytic cell adhesion assay. The results showed that acanthoic acid dose-dependently inhibited LPS-induced TNF-α and IL-8 production. Acanthoic acid also inhibited TNF-α-induced IL-8 and IL-6 production. LPS-induced endothelial cell adhesion molecules, VCAM-1 and ICAM-1 were also inhibited by acanthoic acid. Acanthoic acid inhibited LPS-induced NF-κB activation. Furthermore, acanthoic acid dose-dependently up-regulated the expression of LXRα. In addition, our results showed that the anti-inflammatory effect of acanthoic acid was attenuated by transfection with LXRα siRNA. In conclusion, the anti-inflammatory effect of acanthoic acid is due to its ability to activate LXRα. Acanthoic acid may be a therapeutic agent for inflammatory cardiovascular disease. PMID:26803523

  13. Gallic Acid Induces Necroptosis via TNF–α Signaling Pathway in Activated Hepatic Stellate Cells

    PubMed Central

    Chang, Ya Ju; Hsu, Shih Lan; Liu, Yi Ting; Lin, Yu Hsuan; Lin, Ming Hui; Huang, Shu Jung; Ho, Ja-an Annie; Wu, Li-Chen

    2015-01-01

    Gallic acid (3, 4, 5-trihydroxybenzoic acid, GA), a natural phenolic acid widely found in gallnuts, tea leaves and various fruits, possesses several bioactivities against inflammation, oxidation, and carcinogenicity. The beneficial effect of GA on the reduction of animal hepatofibrosis has been indicated due to its antioxidative property. However, the cytotoxicity of GA autoxidation causing cell death has also been reported. Herein, we postulated that GA might target activated hepatic stellate cells (aHSCs), the cell type responsible for hepatofibrosis, to mitigate the process of fibrosis. The molecular cytotoxic mechanisms that GA exerted on aHSCs were then analyzed. The results indicated that GA elicited aHSC programmed cell death through TNF–α–mediated necroptosis. GA induced significant oxidative stress through the suppression of catalase activity and the depletion of glutathione (GSH). Elevated oxidative stress triggered the production of TNF–α facilitating the undergoing of necroptosis through the up-regulation of key necroptotic regulatory proteins TRADD and receptor-interacting protein 3 (RIP3), and the inactivation of caspase–8. Calmodulin and calpain–1 activation were engaged, which promoted subsequent lysosomal membrane permeabilization (LMP). The TNF–α antagonist (SPD–304) and the RIP1 inhibitor (necrostatin–1, Nec–1) confirmed GA-induced TNFR1–mediated necroptosis. The inhibition of RIP1 by Nec–1 diverted the cell death from necroptosis to apoptosis, as the activation of caspase 3 and the increase of cytochrome c. Collectively, this is the first report indicating that GA induces TNF signaling–triggered necroptosis in aHSCs, which may offer an alternative strategy for the amelioration of liver fibrosis. PMID:25816210

  14. Anacardic acid induces mitochondrial-mediated apoptosis in the A549 human lung adenocarcinoma cells.

    PubMed

    Seong, Yeong-Ae; Shin, Pyung-Gyun; Kim, Gun-Do

    2013-03-01

    Anacardic acid (AA) is a constituent of the cashew nut shell and is known as an inhibitor of nuclear factor-κB (NF-κB). We investigated the cytotoxicity of AA on cancer cells and more experiments to reveal the cell death mechanism focused on A549 lung adenocarcinoma cells for our interest in lung cancer. To examine the molecular mechanism of cell death in AA treated A549 cells, we performed experiments such as transmission electron microscopy (TEM), western blot analysis, fluorescence-activated cell sorting (FACS), genomic DNA extraction and staining with 4',6-diamidino-2-phenylindole (DAPI). For the first time we revealed that AA induces caspase-independent apoptosis with no inhibition of cytotoxicity by pan-caspase inhibitor, Z-VAD-fmk, in A549 cells. Our results showed the possibility of mitochondrial-mediated apoptosis through the activation of apoptosis-inducing factor (AIF) and an intrinsic pathway executioner such as cytochrome c. This study will be helpful in revealing the cell death mechanisms and in developing potential drugs for lung cancer using AA. PMID:23314312

  15. Epoxides Derived from Dietary Dihomo-Gamma-Linolenic Acid Induce Germ Cell Death in C. elegans

    PubMed Central

    Deline, Marshall; Keller, Julia; Rothe, Michael; Schunck, Wolf-Hagen; Menzel, Ralph; Watts, Jennifer L.

    2015-01-01

    Dietary fats are not created equally, slight differences in structure lead to crucial differences in function. Muticellular organisms use polyunsaturated fatty acid as substrates to produce potent signaling molecules crucial for many physiological processes, including reproduction. Here we explored the mechanism responsible for germ cell loss induced by dietary supplementation of dihomo-gamma-linolenic acid (DGLA, 20:3n-6) in the roundworm Caenorhabditis elegans. In this study we found that C. elegans CYP-33E2 activity produces a range of epoxy and hydroxy metabolites from dietary DGLA. Knockdown of cyp-33E2 suppressed the DGLA-induced sterility phenotype. Additionally, direct exposure of two specific DGLA-derived epoxy products, 8,9- and 14,15-epoxyeicosadienoic acids, produced germ cell abnormalities in the C. elegans gonad. We propose that sterility is mediated by the production of toxic DGLA-derived epoxides that trigger germ cell destruction. These studies are the first to establish a biological activity for a CYP-produced metabolite of DGLA. PMID:26486965

  16. Lysophosphatidic Acid Inhibits Apoptosis Induced by Cisplatin in Cervical Cancer Cells

    PubMed Central

    Sui, Yanxia; Yang, Ya; Wang, Ji; Li, Yi; Ma, Hongbing; Cai, Hui; Liu, Xiaoping; Zhang, Yong; Wang, Shufeng; Li, Zongfang; Zhang, Xiaozhi; Wang, Jiansheng; Liu, Rui; Yan, Yanli; Xue, Chaofan; Shi, Xiaowei; Tan, Li; Ren, Juan

    2015-01-01

    Cervical cancer is the second most common cause of cancer death in women worldwide. Lysophosphatidic acid (LPA) level has been found significantly increased in the serum of patients with ovarian, cervical, and colon cancers. LPA level in cervical cancer patients is significantly higher than in healthy controls. LPA receptors were found highly expressed in cervical cancer cells, suggesting LPA may play a role in the development of cervical cancer. The aim of this study is to investigate the effect of LPA on the apoptosis induced by cisplatin (DDP) in cervical cancer cell line and the underlying changes in signaling pathways. Our study found that cisplatin induced apoptosis of Hela cell through inhibiting expression of Bcl-2, upregulating the expression of Bax, Fas-L, and the enzyme activity of caspase-3 (p < 0.05); LPA significantly provided protection against the apoptosis induced by cisplatin by inhibiting the above alterations in apoptotic factor caused by cisplatin (p < 0.05). Moreover, PI3K/AKT pathway was found to be important for the LPA antiapoptosis effect, and administration of PI3K/AKT partially reversed the LPA-mediated protection against cisplatin-induced apoptosis (p < 0.05). These findings have shed new lights on the LPA bioactivity in cervical cancer cells and pointed to a possible sensitization scheme through combined administration of PI3K inhibitor and cisplatin for better treatment of cervical cancer patients, especially those with elevated LPA levels. PMID:26366416

  17. Lysophosphatidic acid induces chemotaxis in MC3T3-E1 osteoblastic cells.

    PubMed

    Masiello, Lisa M; Fotos, Joseph S; Galileo, Deni S; Karin, Norman J

    2006-07-01

    Lysophosphatidic acid (LPA) is a bioactive lipid that has pleiotropic effects on a variety of cell types and enhances the migration of endothelial and cancer cells, but it is not known if this lipid can alter osteoblast motility. We performed transwell migration assays using MC3T3-E1 osteoblastic cells and found LPA to be a potent chemotactic agent. Quantitative time-lapse video analysis of osteoblast migration after wounds were introduced into cell monolayers indicated that LPA stimulated both migration velocity and the average migration distance per cell. LPA also elicited substantial changes in cell shape and actin cytoskeletal structure; lipid-treated cells contained fewer stress fibers and displayed long membrane processes that were enriched in F-actin. Quantitative RT-PCR analysis showed that MC3T3-E1 cells express all four known LPA-specific G-protein-coupled receptors (LPA1-LPA4) with a relative mRNA abundance of LPA1>LPA4>LPA2>LPA3. LPA-induced changes in osteoblast motility and morphology were antagonized by both pertussis toxin and Ki16425, a subtype-specific blocker of LPA1 and LPA3 receptor function. Cell migration in many cell types is linked to changes in intracellular Ca2+. Ki16425 also inhibited LPA-induced Ca2+ signaling in a dose-dependent manner, suggesting a link between LPA-induced Ca2+ transients and osteoblast chemotaxis. Our data show that LPA stimulates MC3T3-E1 osteoblast motility via a mechanism that is linked primarily to the G-protein-coupled receptor LPA1. PMID:16487757

  18. Lysophosphatidic acid induces chemotaxis in MC3T3-E1 osteoblastic cells

    SciTech Connect

    Masiello, Lisa M.; Fotos, Joseph S.; Galileo, Deni S.; Karin, Norm J.

    2006-07-01

    Lysophosphatidic acid (LPA) is a bioactive lipid that has pleiotropic effects on a variety of cell types and enhances the migration of endothelial and cancer cells, but it is not known if this lipid can alter osteoblast motility. We performed transwell migration assays using MC3T3-E1 osteoblastic cells and found LPA to be a potent chemotactic agent. Quantitative time-lapse video analysis of osteoblast migration after wounds were introduced into cell monolayers indicated that LPA stimulated both migration velocity and the average migration distance per cell. LPA also elicited substantial changes in cell shape and actin cytoskeletal structure; lipid-treated cells contained fewer stress fibers and displayed long membrane processes that were enriched in F-actin. Quantitative RT-PCR analysis showed that MC3T3-E1 cells express all four known LPA-specific G protein-coupled receptors (LPA1-LPA4) with a relative mRNA abundance of LPA1 > LPA4 > LPA2 >> LPA3. LPA-induced changes in osteoblast motility and morphology were antagonized by both pertussis toxin and Ki16425, a subtype-specific blocker of LPA1 and LPA3 receptor function. Cell migration in many cell types is linked to changes in intracellular Ca2+. Ki16425 also inhibited LPA-induced Ca2+ signaling in a dose-dependent manner, suggesting a link between LPA-induced Ca2+ transients and osteoblast chemotaxis. Our data show that LPA stimulates MC3T3-E1 osteoblast motility via a mechanism that is linked primarily to the G protein-coupled receptor LPA1.

  19. The role of mast cells in citric acid-induced airway constriction and cough.

    PubMed

    Lai, Yih-Loong; Wu, Li-Ling; Lin, Tai-Yin; Lin, Chien-He

    2009-11-30

    Inhalation of citric acid (CA) causes airway constriction and coughing. To investigate the role of mast cells in CA-induced airway constriction and cough, three experiments using guinea pigs were carried out. In the first experiment, we used compound 48/80 to deplete mast cells, cromolyn sodium to stabilize mast cells, MK-886 to inhibit synthesis of leukotrienes, pyrilamine to antagonize histamine H1 receptor, methysergide to antagonize serotonin receptor, and indomethacin to inhibit cyclooxygenase. In the second experiment, compound 48/80-pretreated animals were divided into 2 parts; the first one was used to test the role of exogenous leukotriene (LT) C4, while the second one to test the role of exogenous histamine. Decreases in respiratory compliance (Crs) and forced expiratory volume in 0.1 sec (FEV0.1) were used as indicators for airway constriction in anesthetized guinea pigs. CA-induced cough was recorded for 12 min using a barometric body plethysmograph in conscious animals. In the third experiment, the activation of mast cells upon CA inhalation was investigated by determining lung tissue or arterial plasma histamine concentration in animals. Exposure to CA induced marked airway constriction and increase in cough number. Compound 48/80, cromolyn sodium, MK-886 and pyrilamine, but not indomethacin or methysergide, significantly attenuated CA-induced airway constriction and cough. Injection of LTC4 or histamine caused a significant increase in CA-induced airway constriction and cough in compound 48/80-pretreated animals. In addition, CA inhalation caused significant increase in lung tissue and plasma histamine concentrations, which were blocked by compound 48/80 pretreatment. These results suggest that mast cells play an important role in CA aerosol inhalation-induced airway constriction and cough via perhaps mediators including LTs and histamine. PMID:20359123

  20. Beneficial effects of chlorogenic acid on alcohol-induced damage in PC12 cells.

    PubMed

    Fang, Shi-Qi; Wang, Yong-Tang; Wei, Jing-Xiang; Shu, Ya-Hai; Xiao, Lan; Lu, Xiu-Min

    2016-04-01

    As one of the most commonly abused psychotropic substances, ethanol exposure has deleterious effects on the central nervous system (CNS). The most detrimental results of ethanol exposure during development are the loss of neurons in brain regions such as the hippocampus and neocortex, which may be related to the apoptosis and necrosis mediated by oxidative stress. Recent studies indicated that a number of natural drugs from plants play an important role in protection of nerve cells from damage. Among these, it has been reported that chlorogenic acid (CA) has neuroprotective effects against oxidative stress. Thus, it may play some beneficial effects on ethanol-induced neurotoxicity. However, the effects of CA on ethanol-induced nerve damage remain unclear. In order to investigate the protective effects of CA on alcohol-induced apoptosis in rat pheochromocytoma PC12 cells, in the present study, cell viability and the optimal dosage of CA were first quantified by MTT assay. Then, the cell apoptosis and cell cycle were respectively investigated by Hoechst 33258 staining and flow cytometer (FCM). To further clarify the possible mechanism, followed with the test of mitochondria transmembrane potential with Rhodamine 123 (Rho 123) staining, the expression of Bcl-2, Capase-3 and growth associated protein-43 (GAP-43) were analyzed by immunofluorescence assay separately. The results showed that treatment with 500mM alcohol decreased the cell viability and then significantly induced apoptosis in PC12 cells. However, when pretreated with different concentrations of CA (1, 5, 10, 50μM), cell viability increased in different degree. Comparatively, CA with the concentration of 10μM most effectively promoted the proliferation of damaged cells, increased the distribution ratio of the cells at the G2/M and S phases, and enhanced mitochondria transmembrane potential. This appears to be in agreement with up-regulation of the expression of Bcl-2 and GAP-43, and down-regulation of the

  1. Carnosic acid induces autophagic cell death through inhibition of the Akt/mTOR pathway in human hepatoma cells.

    PubMed

    Gao, Qilong; Liu, Huaimin; Yao, Yamin; Geng, Liang; Zhang, Xinfeng; Jiang, Lifeng; Shi, Bian; Yang, Feng

    2015-05-01

    The therapeutic goal of cancer treatment is now geared towards triggering tumour-selective cell death with autophagic cell death being required for the chemotherapy of apoptosis-resistant cancer. In this study, Carnosic acid (CA), a polyphenolic diterpene isolated from Rosemary (Rosemarinus officinalis), significantly induced autophagic cell death in HepG2 cells. Ca treatment caused the formation of autophagic vacuoles produced an increasing ratio of LC3-II to LC3-I in a time- and dose-dependent manner but had no effect on the levels of autophagy-related protein ATG6 and ATG13 expression. Autophagy inhibitors, 3-methyladenine (3-MA), chloroquine and bafilomycin A1, or ATG genes silencing in HepG2 cells significantly inhibited CA-induced autophagic cell death. The CA treatment decreased the levels of phosphorylated Akt and mTOR without any effects on PI3K or PTEN. Most importantly, overexpression of Akt and knockdown of PTEN attenuated autophagy induction in CA-treated cells. Taken together, our results indicated that CA induced autophagic cell death through inhibition of the Akt/mTOR pathway in human hepatoma cells. These findings suggest that CA has a great potential for the treatment of hepatoma via autophagic induction. PMID:25178877

  2. Nuclear CD38 in retinoic acid-induced HL-60 cells

    SciTech Connect

    Yalcintepe, Leman . E-mail: lemany@istanbul.edu.tr; Albeniz, Isil; Adin-Cinar, Suzan; Tiryaki, Demir; Bermek, Engin; Graeff, Richard M.; Lee, Hon Cheung

    2005-02-01

    The cell surface antigen, CD38, is a 45-kDa transmembrane protein which is predominantly expressed on hematopoietic cells during differentiation. As a bifunctional ectoenzyme, it catalyzes the synthesis of cyclic ADP-ribose (cADPR) from NAD{sup +} and hydrolysis of either NAD{sup +} or cADPR to ADP-ribose. All-trans-retinoic acid (RA) is a potent and specific inducer of CD38 in myeloid cells. In this report, we demonstrate that the nuclei of RA-treated human HL-60 myeloblastic cells reveal enzymatic activities inherent to CD38. Thus, GDP-ribosyl cyclase and NAD{sup +} glycohydrolase activities in the nuclear fraction increased very significantly in response to incubation with RA. With Western blotting, we detected in the nuclear protein fraction from RA-treated cells a {approx}43-kDa protein band which was reactive with the CD38-specific monoclonal antibody OKT10. The expression of CD38 in HL-60 nuclei was also shown with FACScan analysis. RA treatment gave rise to an increase in in vitro ADP ribosylation of the {approx}43-kDa nuclear protein. Moreover, nuclei isolated from RA-treated HL-60 cells revealed calcium release in response to cADPR, whereas a similar response was not observed in control nuclei. These results suggest that CD38 is expressed in HL-60 cell nuclei during RA-induced differentiation.

  3. The Necrotic Signal Induced by Mycophenolic Acid Overcomes Apoptosis-Resistance in Tumor Cells

    PubMed Central

    Dilhuydy, Marie-Sarah; Pinson, Benoît; Mahfouf, Walid; Pasquet, Jean-Max; Mahon, François-Xavier; Pourquier, Philippe; Moreau, Jean-François; Legembre, Patrick

    2009-01-01

    Background The amount of inosine monophosphate dehydrogenase (IMPDH), a pivotal enzyme for the biosynthesis of the guanosine tri-phosphate (GTP), is frequently increased in tumor cells. The anti-viral agent ribavirin and the immunosuppressant mycophenolic acid (MPA) are potent inhibitors of IMPDH. We recently showed that IMPDH inhibition led to a necrotic signal requiring the activation of Cdc42. Methodology/Principal Findings Herein, we strengthened the essential role played by this small GTPase in the necrotic signal by silencing Cdc42 and by the ectopic expression of a constitutive active mutant of Cdc42. Since resistance to apoptosis is an essential step for the tumorigenesis process, we next examined the effect of the MPA–mediated necrotic signal on different tumor cells demonstrating various mechanisms of resistance to apoptosis (Bcl2-, HSP70-, Lyn-, BCR-ABL–overexpressing cells). All tested cells remained sensitive to MPA–mediated necrotic signal. Furthermore, inhibition of IMPDH activity in Chronic Lymphocytic Leukemia cells was significantly more efficient at eliminating malignant cells than apoptotic inducers. Conclusions/Significance These findings indicate that necrosis and apoptosis are split signals that share few if any common hub of signaling. In addition, the necrotic signaling pathway induced by depletion of the cellular amount of GTP/GDP would be of great interest to eliminate apoptotic-resistant tumor cells. PMID:19430526

  4. Methoxyacetic acid suppresses prostate cancer cell growth by inducing growth arrest and apoptosis

    PubMed Central

    Parajuli, Keshab R; Zhang, Qiuyang; Liu, Sen; Patel, Neil K; Lu, Hua; Zeng, Shelya X; Wang, Guangdi; Zhang, Changde; You, Zongbing

    2014-01-01

    Methoxyacetic acid (MAA) is a primary metabolite of ester phthalates that are used in production of consumer products and pharmaceutical products. MAA causes embryo malformation and spermatocyte death through inhibition of histone deacetylases (HDACs). Little is known about MAA’s effects on cancer cells. In this study, two immortalized human normal prostatic epithelial cell lines (RWPE-1 and pRNS-1-1) and four human prostate cancer cell lines (LNCaP, C4-2B, PC-3, and DU-145) were treated with MAA at different doses and for different time periods. Cell viability, apoptosis, and cell cycle analysis were performed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR, Western blot, and chromatin immunoprecipitation analyses. We found that MAA dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. MAA-induced apoptosis was due to down-regulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2, also named cIAP1), leading to activation of caspases 7 and 3 and turning on the downstream apoptotic events. MAA-induced cell cycle arrest (mainly G1 arrest) was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4 (CDK4) and CDK2 expression at the late time. MAA up-regulated p21 expression through inhibition of HDAC activities, independently of p53/p63/p73. These findings demonstrate that MAA suppresses prostate cancer cell growth by inducing growth arrest and apoptosis, which suggests that MAA could be used as a potential therapeutic drug for prostate cancer. PMID:25606576

  5. Nutraceutical with Resveratrol and Omega-3 Fatty Acids Induces Autophagy in ARPE-19 Cells

    PubMed Central

    Koskela, Ali; Reinisalo, Mika; Petrovski, Goran; Sinha, Debasish; Olmiere, Céline; Karjalainen, Reijo; Kaarniranta, Kai

    2016-01-01

    Impaired autophagic and proteasomal cleansing have been documented in aged retinal pigment epithelial (RPE) cells and age-related macular degeneration (AMD). Omega-3 fatty acids and resveratrol have many positive homeostatic effects in RPE cells. In this work, ARPE-19 cells were treated with 288 ng of Resvega, containing 30 mg of trans resveratrol and 665 mg of omega-3 fatty acids, among other nutrients, with proteasome inhibitor MG-132 or autophagy inhibitor bafilomycin A1 up to 48 h. Autophagy markers p62/SQSTM1 (p62) and LC3 (microtubule-associated protein 1A/1B-light chain 3) were analyzed by Western blotting. Fluorescence microscopy with mCherry-GFP-LC3 plasmid was applied to study the autophagy flux, and cytoprotective effects were investigated with colorimetric MTT and LDH assays. Resvega induced autophagy by showing increased autolysosome formation and autophagy flux, and the change in the p62 and LC3 protein levels further confirmed the fluorescent microscopy results. Moreover, Resvega provided a clear cytoprotection under proteasome inhibition. These findings highlight the potential of the nutraceuticals containing resveratrol, omega-3 fatty acids and other nutrients in the prevention of ARPE-19 cell damage. PMID:27187449

  6. Nutraceutical with Resveratrol and Omega-3 Fatty Acids Induces Autophagy in ARPE-19 Cells.

    PubMed

    Koskela, Ali; Reinisalo, Mika; Petrovski, Goran; Sinha, Debasish; Olmiere, Céline; Karjalainen, Reijo; Kaarniranta, Kai

    2016-01-01

    Impaired autophagic and proteasomal cleansing have been documented in aged retinal pigment epithelial (RPE) cells and age-related macular degeneration (AMD). Omega-3 fatty acids and resveratrol have many positive homeostatic effects in RPE cells. In this work, ARPE-19 cells were treated with 288 ng of Resvega, containing 30 mg of trans resveratrol and 665 mg of omega-3 fatty acids, among other nutrients, with proteasome inhibitor MG-132 or autophagy inhibitor bafilomycin A1 up to 48 h. Autophagy markers p62/SQSTM1 (p62) and LC3 (microtubule-associated protein 1A/1B-light chain 3) were analyzed by Western blotting. Fluorescence microscopy with mCherry-GFP-LC3 plasmid was applied to study the autophagy flux, and cytoprotective effects were investigated with colorimetric MTT and LDH assays. Resvega induced autophagy by showing increased autolysosome formation and autophagy flux, and the change in the p62 and LC3 protein levels further confirmed the fluorescent microscopy results. Moreover, Resvega provided a clear cytoprotection under proteasome inhibition. These findings highlight the potential of the nutraceuticals containing resveratrol, omega-3 fatty acids and other nutrients in the prevention of ARPE-19 cell damage. PMID:27187449

  7. Carnosic Acid Induces Apoptosis Through Reactive Oxygen Species-mediated Endoplasmic Reticulum Stress Induction in Human Renal Carcinoma Caki Cells

    PubMed Central

    Min, Kyoung-jin; Jung, Kyong-Jin; Kwon, Taeg Kyu

    2014-01-01

    Background: Carnosic acid, which is one of extract components of rosemary, has anti-inflammatory, anti-oxidant, and anti-cancer effects. However, the anti-cancer effect of carnosic acid in human renal carcinoma cells is unknown. Methods: Flow cytometry analysis was used to examine the effects of carnosic acid on apoptosis, and Asp-Glu-Val-Asp-ase activity assay kit was used to investigate the involvement of caspase activation. To determine protein expression of apoptotic and endoplasmic reticulum (ER) stress-related proteins, we used Western blotting. Intracellular accumulation of reactive oxygen species (ROS) was determined using the fluorescent probes 2’, 7’-dichlorodihydrofluorescein diacetate (H2DCFDA). Results: Carnosic acid induced sub-diploid DNA content, sub-G1, population and poly (ADP-ribose) polymerase (PARP) cleavage and activated caspase-3. A pan-caspase inhibitor, a benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone, markedly reduced apoptosis in carnosic acid-treated cells. Carnosic acid promoted intracellular ROS production, and pretreatment with the ROS scavengers (N-acetyl-L-cysteine and glutathione ethyl ester) inhibited carnosic acid-induced apoptosis. Furthermore, carnosic acid also induced expression of ER stress marker proteins, including activating transcription factor 4 (ATF4) and CCAAT/enhancer-binding protein-homologous protein (CHOP), in a dose- and time-dependent manner. Down-regulation of ATF4 and CHOP by small interfering RNA (siRNA) markedly reduced carnosic acid-induced sub-G1 population and PARP cleavage. In addition, carnosic acid induced apoptosis in human breast carcinoma MDA-MB-361 and human hepatocellular carcinoma SK-HEP1 cells, but not in normal human skin fibroblast cells and normal mouse kidney epithelial TMCK-1 cells. Conclusion: Carnosic acid induced apoptosis through production of ROS and induction of ER stress in human renal carcinoma Caki cells. PMID:25337586

  8. Calcium mobilization in salicylic acid-induced Salvia miltiorrhiza cell cultures and its effect on the accumulation of rosmarinic acid.

    PubMed

    Guo, Hongbo; Zhu, Nan; Deyholos, Michael K; Liu, Jun; Zhang, Xiaoru; Dong, Juane

    2015-03-01

    Ca(2+) serves as a second messenger in plant responses to different signals, and salicylic acid (SA) has been recognized as a signal mediating plant responses to many stresses. We recently found that SA treatment led to the cytoplasmic acidification of Salvia miltiorrhiza cells and alkalinization of extracellular medium. Here, we demonstrate that SA can rapidly induce Ca(2+) mobilization in protoplasts, but the induction can be blocked with a channel blocker of either plasma or organellar membranes. Following SA, A 23187, or 10 mmol/L Ca(2+) treatment, rosmarinic acid (RA) accumulation reached the highest level at 16 h, whereas the peak was found at 10 h if plasma membrane channel blockers were used. By contrast, the highest accumulation of RA occurred at 16 h when organellar channels were blocked, exhibiting the same tendency with SA-induced cells. In agreement with these observations, both phenylalanine ammonia-lyase (PAL) activity and its gene expression detected by real-time PCR also showed the same patterns. These results indicate that SA treatment firstly results in calcium release from internal stores, which in turn leads to PAL activity increase, RA accumulation, and a large amount of Ca(2+) influx from apoplast after 10 h of SA induction. PMID:25561058

  9. Potential in vitro Protective Effect of Quercetin, Catechin, Caffeic Acid and Phytic Acid against Ethanol-Induced Oxidative Stress in SK-Hep-1 Cells

    PubMed Central

    Lee, Ki-Mo; Kang, Hyung-Sik; Yun, Chul-Ho; Kwak, Hahn-Shik

    2012-01-01

    Phytochemicals have been known to exhibit potent antioxidant activity. This study examined cytoprotective effects of phytochemicals including quercetin, catechin, caffeic acid, and phytic acid against oxidative damage in SK-Hep-1 cells induced by the oxidative and non-oxidative metabolism of ethanol. Exposure of the cells to excess ethanol resulted in a significant increase in cytotoxicity, reactive oxygen species (ROS) production, lipid hydroperoxide (LPO), and antioxidant enzyme activity. Excess ethanol also caused a reduction in mitochondrial membrane potential (MMP) and the quantity of reduced glutathione (GSH). Co-treatment of cells with ethanol and quercetin, catechin, caffeic acid and phytic acid significantly inhibited oxidative ethanol metabolism-induced cytotoxicity by blocking ROS production. When the cells were treated with ethanol after pretreatment of 4-methylpyrazole (4-MP), increased cytotoxicity, ROS production, antioxidant enzyme activity, and loss of MMP were observed. The addition of quercetin, catechin, caffeic acid and phytic acid to these cells showed suppression of non-oxidative ethanol metabolism-induced cytotoxicity, similar to oxidative ethanol metabolism. These results suggest that quercetin, catechin, caffeic acid and phytic acid have protective effects against ethanol metabolism-induced oxidative insult in SK-Hep-1 cells by blocking ROS production and elevating antioxidant potentials. PMID:24009840

  10. Mechanism of the toxicity induced by natural humic acid on human vascular endothelial cells.

    PubMed

    Kihara, Yusuke; Yustiawati; Tanaka, Masato; Gumiri, Sulmin; Ardianor; Hosokawa, Toshiyuki; Tanaka, Shunitz; Saito, Takeshi; Kurasaki, Masaaki

    2014-08-01

    Humic acid (HA), a group of high-molecular weight organic compounds characterized by an ability to bind heavy metals, is normally found in natural water. Although the impairment of vascular endothelial cells in the presence of humic substances has been reported to be involved in some diseases, the mechanisms responsible for this involvement remain unclear. In this study, we examined the cytotoxicity of HA obtained from peatland in Central Kalimantan, Indonesia, to human vascular endothelial cells, as well as the mechanisms behind these effects. It was found that 50 mg/L HA showed cytotoxicity, which we considered to be mediated by apoptosis through the mitochondrial pathway because of an increase in the expression of caspases 6 and 9 in response to HA administration. In addition, this cytotoxicity was enhanced when cells in this experimental system were exposed to oxidative stress, while it was decreased by the addition of vitamin C. Thus, we conclude that the apoptosis induced by HA depends upon oxidative stress. Furthermore, an iron chelator, DFO, showed a tendency to decrease HA-induced cytotoxicity, suggesting that iron may potentially mediate HA-induced oxidative stress. In conclusion, long-term consumption of HA-rich water obtained from our study area may cause damage to endothelial cells and subsequent chronic health problems. PMID:23042718

  11. Investigation of the apoptotic way induced by digallic acid in human lymphoblastoid TK6 cells

    PubMed Central

    2012-01-01

    Background The digallic acid (DGA) purified from Pistacia lentiscus. L fruits was investigated for its antiproliferative and apoptotic activities on human lymphoblastoid TK6 cells. Methods We attempt to characterize the apoptotic pathway activated by DGA. Apoptosis was detected by DNA fragmentation, PARP cleavage and by evaluating caspase activities. Results The inhibition of lymphoblastoid cell proliferation was noted from 8.5 μg/ml of DGA. The induction of apoptosis was confirmed by DNA fragmentation and PARP cleavage. We have demonstrated that DGA induces apoptosis by activating the caspase-8 extrinsic pathway. Caspase-3 was also activated in a dose dependent manner. Conclusion In summary, DGA exhibited an apoptosis inductor effect in TK6 cells revealing thus its potential as a cancer-preventive agent. PMID:22686580

  12. Proteins implicated in the increase of adhesivity induced by suberoylanilide hydroxamic acid in leukemic cells.

    PubMed

    Grebeňová, D; Röselová, P; Pluskalová, M; Halada, P; Rösel, D; Suttnar, J; Brodská, B; Otevřelová, P; Kuželová, K

    2012-12-21

    We have previously shown that suberoylanilide hydroxamic acid (SAHA) treatment increases the adhesivity of leukemic cells to fibronectin at clinically relevant concentrations. Now, we present the results of the proteomic analysis of SAHA effects on leukemic cell lines using 2-DE and ProteomLab PF2D system. Histone acetylation at all studied acetylation sites reached the maximal level after 5 to 10 h of SAHA treatment. No difference in histone acetylation between subtoxic and toxic SAHA doses was observed. SAHA treatment induced cofilin phosphorylation at Ser3, an increase in vimentin and paxillin expression and a decrease in stathmin expression as confirmed by western-blotting and immunofluorescence microscopy. The interaction of cofilin with 14-3-3 epsilon was documented using both Duolink system and coimmunoprecipitation. However, this interaction was independent of cofilin Ser3 phosphorylation and the amount of 14-3-3-ε-bound cofilin did not rise following SAHA treatment. SAHA-induced increase in the cell adhesivity was associated with an increase in PAK phosphorylation in CML-T1 cells and was abrogated by simultaneous treatment with IPA-3, a PAK inhibitor. The effects of SAHA on JURL-MK1 cells were similar to those of other histone deacetylase inhibitors, tubastatin A and sodium butyrate. The proteome analysis also revealed several potential non-histone targets of histone deacetylases. PMID:23022583

  13. Sonic hedgehog and retinoic Acid induce bone marrow-derived stem cells to differentiate into glutamatergic neural cells.

    PubMed

    Yu, Zhenhai; Wu, Shixing; Liu, Zhen; Lin, Haiyan; Chen, Lei; Yuan, Xinli; Zhang, Zhiying; Liu, Fang; Zhang, Chuansen

    2015-01-01

    Studies have showed that transplanted stem cells in the inner ear won't regenerate to replace the damaged sensory hair cells. They can spontaneously differentiate into mesenchymal cells and fibrocytes in the damaged inner ear. Only mature sensory cells of MSCs-derived possess the great potency for cell transplantation in the treatment of sensorineural hearing loss. So, we try to establish an efficient generation of the glutamatergic sensory neural phenotype for the cell transplantation of the hearing loss. We isolated MSCs from femoral and tibial bones according to their adherence to culture dishes. After purification, proliferation, and passaged, cells became homogeneous in appearance, showing more uniformity and grew in a monolayer with a typical spindle-shape morphology. The cell surface markers were assessed using FACS to characterize the isolated cells. For neural induction to harvest the glutamatergic sensory neurons, passage 3 MSCs were incubated with preinduced medium for 24 hr, and neural-induced medium for an additional 14 days. The cells exhibit a typical neural shape. RT-PCR analysis indicated that the mRNA levels of the neural cell marker nestin, Tau, MAP-2, β-tubulin III, GluR-3, and GluR-4 were higher compared with primary MSCs. Immunohistochemistry and western-blotting proofed that nestin, MAP-2, β-tubulin III, and GluR-4 proteins indeed exhibit their expression difference in the induced cells compared to the MSCs. We show an efficient protocol by the combined applications of Sonic Hedgehog (Shh) and Retinoic Acid (RA) to induce MSCs to differentiate into the glutamatergic sensory neuron which were identified from the morphological, biochemical, and molecular characteristics. PMID:24547891

  14. The Acid Growth Theory of auxin-induced cell elongation is alive and well

    NASA Technical Reports Server (NTRS)

    Rayle, D. L.; Cleland, R. E.

    1992-01-01

    Plant cells elongate irreversibly only when load-bearing bonds in the walls are cleaved. Auxin causes the elongation of stem and coleoptile cells by promoting wall loosening via cleavage of these bonds. This process may be coupled with the intercalation of new cell wall polymers. Because the primary site of auxin action appears to be the plasma membrane or some intracellular site, and wall loosening is extracellular, there must be communication between the protoplast and the wall. Some "wall-loosening factor" must be exported from auxin-impacted cells, which sets into motion the wall loosening events. About 20 years ago, it was suggested that the wall-loosening factor is hydrogen ions. This idea and subsequent supporting data gave rise to the Acid Growth Theory, which states that when exposed to auxin, susceptible cells excrete protons into the wall (apoplast) at an enhanced rate, resulting in a decrease in apoplastic pH. The lowered wall pH then activates wall-loosening processes, the precise nature of which is unknown. Because exogenous acid causes a transient (1-4 h) increase in growth rate, auxin must also mediate events in addition to wall acidification for growth to continue for an extended period of time. These events may include osmoregulation, cell wall synthesis, and maintenance of the capacity of walls to undergo acid-induced wall loosening. At present, we do not know if these phenomena are tightly coupled to wall acidification or if they are the products of multiple independent signal transduction pathways.

  15. Nitro-Arachidonic Acid Prevents Angiotensin II-Induced Mitochondrial Dysfunction in a Cell Line of Kidney Proximal Tubular Cells

    PubMed Central

    Sánchez-Calvo, Beatriz; Cassina, Adriana; Rios, Natalia; Boggia, José; Radi, Rafael; Rubbo, Homero; Trostchansky, Andres

    2016-01-01

    Nitro-arachidonic acid (NO2-AA) is a cell signaling nitroalkene that exerts anti-inflammatory activities during macrophage activation. While angiotensin II (ANG II) produces an increase in reactive oxygen species (ROS) production and mitochondrial dysfunction in renal tubular cells, little is known regarding the potential protective effects of NO2-AA in ANG II-mediated kidney injury. As such, this study examines the impact of NO2-AA on ANG II-induced mitochondrial dysfunction in an immortalized renal proximal tubule cell line (HK-2 cells). Treatment of HK-2 cells with ANG II increases the production of superoxide (O2●-), nitric oxide (●NO), inducible nitric oxide synthase (NOS2) expression, peroxynitrite (ONOO-) and mitochondrial dysfunction. Using high-resolution respirometry, it was observed that the presence of NO2-AA prevented ANG II-mediated mitochondrial dysfunction. Attempting to address mechanism, we treated isolated rat kidney mitochondria with ONOO-, a key mediator of ANG II-induced mitochondrial damage, in the presence or absence of NO2-AA. Whereas the activity of succinate dehydrogenase (SDH) and ATP synthase (ATPase) were diminished upon exposure to ONOO-, they were restored by pre-incubating the mitochondria with NO2-AA. Moreover, NO2-AA prevents oxidation and nitration of mitochondrial proteins. Combined, these data demonstrate that ANG II-mediated oxidative damage and mitochondrial dysfunction is abrogated by NO2-AA, identifying this compound as a promising pharmacological tool to prevent ANG II–induced renal disease. PMID:26943326

  16. Fusaric acid induces mitochondrial stress in human hepatocellular carcinoma (HepG2) cells.

    PubMed

    Sheik Abdul, Naeem; Nagiah, Savania; Chuturgoon, Anil A

    2016-09-01

    Fusarium spp are common contaminants of maize and produce many mycotoxins, including the fusariotoxin fusaric acid (FA). FA is a niacin related compound, chelator of divalent cations, and mediates toxicity via oxidative stress and possible mitochondrial dysregulation. Sirtuin 3 (SIRT3) is a stress response deacetylase that maintains proper mitochondrial function. We investigated the effect of FA on SIRT3 and oxidative and mitochondrial stress pathways in the hepatocellular carcinoma (HepG2) cell line. We determined FA toxicity (24 h incubation; IC50 = 104 μg/ml) on mitochondrial output, cellular and mitochondrial stress responses, mitochondrial biogenesis and markers of cell death using spectrophotometry, luminometry, qPCR and western blots. FA caused a dose dependent decrease in metabolic activity along with significant depletion of intracellular ATP. FA induced a significant increase in lipid peroxidation, despite up-regulation of the antioxidant transcription factor, Nrf2. FA significantly decreased expression of SIRT3 mRNA with a concomitant decrease in protein expression. Lon protease was also significantly down-regulated. FA induced aberrant mitochondrial biogenesis as evidenced by significantly decreased protein expressions of: PGC-1α, p-CREB, NRF1 and HSP70. Finally, FA activated apoptosis as noted by the significantly increased activity of caspases 3/7 and also induced cellular necrosis. This study provides insight into the molecular mechanisms of FA (a neglected mycotoxin) induced hepatotoxicity. PMID:27390038

  17. SPATIAL MEMORY IMPAIRMENT AND HIPPOCAMPAL CELL LOSS INDUCED BY OKADAIC ACID (EXPERIMENTAL STUDY).

    PubMed

    Chighladze, M; Dashniani, M; Beselia, G; Kruashvili, L; Naneishvili, T

    2016-01-01

    In the present study, we evaluated and compared effect of intracerebroventricular (ICV) and intrahippocampal bilateral microinjection of okadaic acid (OA) on spatial memory function assessed in one day water maze paradigm and hippocampal structure in rats. Rats were divided in following groups: Control(icv) - rats injected with ICV and aCSF; Control(hipp) - rats injected intrahippocampally with aCSF; OAicv - rats injected with ICV and OA; OAhipp - rats injected intrahippocampally with OA. Nissl staining of hippocampal sections showed that the pyramidal cell loss in OAhipp group is significantly higher than that in the OAicv. The results of behavioral experiments showed that ICV or intrahippocampal bilateral microinjection of OA did not affect learning process and short-term spatial memory but induced impairment in spatial long-term memory assessed in probe test performance 24 h after training. OA-induced spatial memory impairment may be attributed to the hippocampal cell death. Based on these results OA induced memory deficit and hippocampal cell loss in rat may be considered as a potential animal model for preclinical evaluation of antidementic drug activity. PMID:26870981

  18. Rhabdovirus-induced apoptosis in a fish cell line is inhibited by a human endogenous acid cysteine proteinase inhibitor.

    PubMed Central

    Björklund, H V; Johansson, T R; Rinne, A

    1997-01-01

    To determine the mechanisms of cell death in rhabdovirus-infected cells, we studied the infection of the epithelial papilloma of carp cell line with spring viremia of carp virus. Studies using electron microscopy, confocal microscopy, and agarose gel electrophoresis revealed changes in cell morphology and DNA fragmentation indicative of apoptosis. The virus-induced apoptosis was inhibited in cells treated with a human endogenous acid cysteine proteinase inhibitor. PMID:9188644

  19. Trans Fatty Acids Induce Vascular Inflammation and Reduce Vascular Nitric Oxide Production in Endothelial Cells

    PubMed Central

    Iwata, Naomi G.; Pham, Matilda; Rizzo, Norma O.; Cheng, Andrew M.; Maloney, Ezekiel; Kim, Francis

    2011-01-01

    Intake of trans fatty acids (TFA), which are consumed by eating foods made from partially hydrogenated vegetable oils, is associated with a higher risk of cardiovascular disease. This relation can be explained by many factors including TFA's negative effect on endothelial function and reduced nitric oxide (NO) bioavailability. In this study we investigated the effects of three different TFA (2 common isomers of C18 found in partially hydrogenated vegetable oil and a C18 isomer found from ruminant-derived—dairy products and meat) on endothelial NF-κB activation and nitric oxide (NO) production. Human endothelial cells were treated with increasing concentrations of Elaidic (trans-C18:1 (9 trans)), Linoelaidic (trans-C18:2 (9 trans, 12 trans)), and Transvaccenic (trans-C18:1 (11 trans)) for 3 h. Both Elaidic and Linoelaidic acids were associated with increasing NF-κB activation as measured by IL-6 levels and phosphorylation of IκBα, and impairment of endothelial insulin signaling and NO production, whereas Transvaccenic acid was not associated with these responses. We also measured superoxide production, which has been hypothesized to be necessary in fatty acid-dependent activation of NF-κB. Both Elaidic acid and Linoelaidic acid are associated with increased superoxide production, whereas Transvaccenic acid (which did not induce inflammatory responses) did not increase superoxide production. We observed differential activation of endothelial superoxide production, NF-κB activation, and reduction in NO production by different C18 isomers suggesting that the location and number of trans double bonds effect endothelial NF-κB activation. PMID:22216328

  20. Acidic microenvironments induce lymphangiogenesis and IL-8 production via TRPV1 activation in human lymphatic endothelial cells.

    PubMed

    Nakanishi, Masako; Morita, Yoshihiro; Hata, Kenji; Muragaki, Yasuteru

    2016-07-15

    Local acidosis is one of the characteristic features of the cancer microenvironment. Many reports indicate that acidosis accelerates the proliferation and invasiveness of cancer cells. However, whether acidic conditions affect lymphatic metastasis is currently unknown. In the present study, we focused on the effects of acidosis on lymphatic endothelial cells (LECs) to assess the relationship between acidic microenvironments and lymph node metastasis. We demonstrated that normal human LECs express various acid receptors by immunohistochemistry and reverse transcriptase-polymerase chain reaction (PCR). Acidic stimulation with low pH medium induced morphological changes in LECs to a spindle shape, and significantly promoted cellular growth and tube formation. Moreover, real-time PCR revealed that acidic conditions increased the mRNA expression of interleukin (IL)-8. Acidic stimulation increased IL-8 production in LECs, whereas a selective transient receptor potential vanilloid subtype 1 (TRPV1) antagonist, 5'-iodoresiniferatoxin, decreased IL-8 production. IL-8 accelerated the proliferation of LECs, and inhibition of IL-8 diminished tube formation and cell migration. In addition, phosphorylation of nuclear factor (NF)-κB was induced by acidic conditions, and inhibition of NF-κB activation reduced acid-induced IL-8 expression. These results suggest that acidic microenvironments in tumors induce lymphangiogenesis via TRPV1 activation in LECs, which in turn may promote lymphatic metastasis. PMID:27312995

  1. Mechanisms of omega-3 fatty acid-induced growth inhibition in MDA-MB-231 human breast cancer cells.

    PubMed

    Schley, Patricia D; Jijon, Humberto B; Robinson, Lindsay E; Field, Catherine J

    2005-07-01

    The omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), inhibit the growth of human breast cancer cells in animal models and cell lines, but the mechanism by which this occurs is not well understood. In order to explore possible mechanisms for the modulation of breast cancer cell growth by omega-3 fatty acids, we examined the effects of EPA and DHA on the human breast cancer cell line MDA-MB-231. Omega-3 fatty acids (a combination of EPA and DHA) inhibited the growth of MDA-MB-231 cells by 30-40% (p<0.05) in both the presence and absence of linoleic acid, an essential omega-6 fatty acid. When provided individually, DHA was more potent than EPA in inhibiting the growth of MDA-MB-231 cells (p<0.05). EPA and DHA treatment decreased tumor cell proliferation (p<0.05), as estimated by decreased [methyl-(3)H]-thymidine uptake and expression of proliferation-associated proteins (proliferating cell nuclear antigen, PCNA, and proliferation-related kinase, PRK). In addition, EPA and DHA induced apoptosis, as indicated by a loss of mitochondrial membrane potential, increased caspase activity and increased DNA fragmentation (p<0.05). Cells incubated with omega-3 fatty acids demonstrated decreased Akt phosphorylation, as well as NFkappaB DNA binding activity (p<0.05). The results of this study indicate that omega-3 fatty acids decrease cell proliferation and induce apoptotic cell death in human breast cancer cells, possibly by decreasing signal transduction through the Akt/NFkappaB cell survival pathway. PMID:15986129

  2. Folic Acid Protected Neural Cells Against Aluminum-Maltolate-Induced Apoptosis by Preventing miR-19 Downregulation.

    PubMed

    Zhu, Mingming; Li, Bingfei; Ma, Xiao; Huang, Cong; Wu, Rui; Zhu, Weiwei; Li, Xiaoting; Liang, Zhaofeng; Deng, Feifei; Zhu, Jianyun; Xie, Wei; Yang, Xue; Jiang, Ye; Wang, Shijia; Wu, Jieshu; Geng, Shanshan; Xie, Chunfeng; Zhong, Caiyun; Liu, Haiyan

    2016-08-01

    Aluminum (Al)-induced apoptosis is considered as the major cause of its neurotoxicity. Folic acid possesses neuroprotective function by preventing neural cell apoptosis. microRNAs (miRNAs) are important regulators of gene expression participating in cellular processes. As a key component of the miR-17-92 cluster, miR-19 is implicated in regulating apoptotic process, while its role in the neuroprotective effect of folic acid has not been investigated. The present study aimed to investigate the potential involvement and function of miR-19 in the protective action of folic acid against Al-induced neural cell apoptosis. Human SH-SY5Y cells were treated with Al-maltolate (Al-malt) in the presence or absence of folic acid. Results showed that Al-malt-induced apoptosis of SH-SY5Y cells was effectively prevented by folic acid. Al-malt suppressed the expression of miR-19a/19b, along with alterations of miR-19 related apoptotic proteins including PTEN, p-AKT, p53, Bax, Bcl-2, caspase 9 and caspase 3; and these effects were ameliorated by folic acid. miR-19 inhibitor alone induced apoptosis of SH-SY5Y cells. Combination treatment of folic acid and miR-19 inhibitor diminished the neuroprotective effect of folic acid. These findings demonstrated that folic acid protected neuronal cells against Al-malt-induced apoptosis by preventing the downregulation of miR-19 and modulation of miR-19 related downstream PTEN/AKT/p53 pathway. PMID:27113042

  3. Human myeloblastic leukemia cells (HL-60) express a membrane receptor for estrogen that signals and modulates retinoic acid-induced cell differentiation

    SciTech Connect

    Kauss, M. Ariel; Reiterer, Gudrun; Bunaciu, Rodica P.; Yen, Andrew

    2008-10-01

    Estrogen receptors are historically perceived as nuclear ligand activated transcription factors. An estrogen receptor has now been found localized to the plasma membrane of human myeloblastic leukemia cells (HL-60). Its expression occurs throughout the cell cycle, progressively increasing as cells mature from G{sub 1} to S to G{sub 2}/M. To ascertain that the receptor functioned, the effect of ligands, including a non-internalizable estradiol-BSA conjugate and tamoxifen, an antagonist of nuclear estrogen receptor function, were tested. The ligands caused activation of the ERK MAPK pathway. They also modulated the effect of retinoic acid, an inducer of MAPK dependent terminal differentiation along the myeloid lineage in these cells. In particular the ligands inhibited retinoic acid-induced inducible oxidative metabolism, a functional marker of terminal myeloid cell differentiation. To a lesser degree they also diminished retinoic acid-induced earlier markers of cell differentiation, namely CD38 and CD11b. However, they did not regulate retinoic acid-induced G{sub 0} cell cycle arrest. There is thus a membrane localized estrogen receptor in HL-60 myeloblastic leukemia cells that can cause ERK activation and modulates the response of these cells to retinoic acid, indicating crosstalk between the membrane estrogen and retinoic acid evoked pathways relevant to propulsion of cell differentiation.

  4. Human myeloblastic leukemia cells (HL-60) express a membrane receptor for estrogen that signals and modulates retinoic acid-induced cell differentiation.

    PubMed

    Kauss, M Ariel; Reiterer, Gudrun; Bunaciu, Rodica P; Yen, Andrew

    2008-10-01

    Estrogen receptors are historically perceived as nuclear ligand activated transcription factors. An estrogen receptor has now been found localized to the plasma membrane of human myeloblastic leukemia cells (HL-60). Its expression occurs throughout the cell cycle, progressively increasing as cells mature from G(1) to S to G(2)/M. To ascertain that the receptor functioned, the effect of ligands, including a non-internalizable estradiol-BSA conjugate and tamoxifen, an antagonist of nuclear estrogen receptor function, were tested. The ligands caused activation of the ERK MAPK pathway. They also modulated the effect of retinoic acid, an inducer of MAPK dependent terminal differentiation along the myeloid lineage in these cells. In particular the ligands inhibited retinoic acid-induced inducible oxidative metabolism, a functional marker of terminal myeloid cell differentiation. To a lesser degree they also diminished retinoic acid-induced earlier markers of cell differentiation, namely CD38 and CD11b. However, they did not regulate retinoic acid-induced G(0) cell cycle arrest. There is thus a membrane localized estrogen receptor in HL-60 myeloblastic leukemia cells that can cause ERK activation and modulates the response of these cells to retinoic acid, indicating crosstalk between the membrane estrogen and retinoic acid evoked pathways relevant to propulsion of cell differentiation. PMID:18692045

  5. Inhibitory effect of schisandrin B on free fatty acid-induced steatosis in L-02 cells

    PubMed Central

    Chu, Jian-Hong; Wang, Hui; Ye, Yan; Chan, Ping-Kei; Pan, Si-Yuan; Fong, Wang-Fun; Yu, Zhi-Ling

    2011-01-01

    AIM: To investigate the effects of schisandrin B (Sch B) on free fatty acid (FFA)-induced steatosis in L-02 cells. METHODS: Cellular steatosis was induced by incubating L-02 cells with a FFA mixture (oleate and palmitate at the ratio of 2:1) for 24 h. Cytotoxicity and apoptosis were evaluated by 3-(4, 5-dmethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay and Annexin V/propidium iodide staining, respectively. Cellular total lipid was determined using a photocolorimetric method after Nile red staining, and triglyceride content was measured using an enzymatic kit. To study the effects of Sch B on steatosis, L-02 cells were treated with Sch B (1-100 μmol/L) in the absence or presence of 1 mmol/L FFA for 24 h, and cellular total lipid and triglyceride levels were measured. To explore the mechanisms of action of Sch B in the steatotic L-02 cells, mRNA levels of several regulators of hepatic lipid metabolism including adipose differentiation related protein (ADRP), sterol regulatory element binding protein 1 (SREBP-1), peroxisome proliferator-activated receptor (PPAR)-α and PPAR-γ were measured by quantitative real-time polymerase chain reaction (PCR), and protein levels of ADRP and SREBP-1 were measured by immunoblotting. RESULTS: Treatment with 1 mmol/L FFA for 24 h induced intracellular lipid accumulation in L-02 cells comparable to that in human steatotic livers without causing apparent apoptosis and cytotoxicity. Sch B mitigated cellular total lipid and triglyceride accumulations in the steatotic L-02 cells in a dose-dependent manner. Quantitative real-time PCR and Western blot analyses revealed that treatment of L-02 cells with 100 μmol/L Sch B reverted the FFA-stimulated up-regulation of ADRP and SREBP-1. CONCLUSION: Sch B inhibits FFA-induced steatosis in L-02 cells by, at least in part, reversing the up-regulation of ADRP and SREBP-1. PMID:21633637

  6. Ozone-induced alterations in arachidonic acid metabolism in cultured lung cell types

    SciTech Connect

    Madden, M.C.

    1986-01-01

    One of the most sensitive cells to ozone (O/sub 3/) damage is the pulmonary endothelial cell which may mediate the response of the lung to injury by productions of the autacoid prostacyclin (PGl/sub 2/), a metabolite of arachidonic acid. Exposure of endothelial cell cultures to ozone produced a concentration dependent decreases in the synthesis of PGl/sub 2/. Release of /sup 3/H-arachidonic acid from endothelial cells was increased after two hours of 0.3 and 1.0 ppm O/sub 3/ exposure while incubation of cells with 20 ..mu..M and arachidonate (4 min) after exposure resulted in a decreased PGl/sub 2/ synthesis. Cells exposed to 1.0 ppm O/sub 3/ did not have a decreased PGl/sub 2/ production when incubated with 5 ..mu..M PGH/sub 2/ immediately after exposure. These results are consistent with an O/sub 3/-induced inhibition of cyclooxygenase activity. O/sub 3/ exposure (1.0 ppm) produced a rapid decrease in endothelial PGl/sub 2/ synthesis. The data suggest that cyclooxygenase was not inactivated by increased autooxidation due to metabolism of increased free arachidonate. PGl/sub 2/ synthesis returned to control amounts within 12 hours after ozone exposure similar to the recovery time of irreversibly inhibited cyclooxygenase suggesting that recovery was due to de novo synthesis of enzyme. Lipid peroxides and/or hydrogen peroxide (H/sub 2/O/sub 2/) may have caused the inhibition of cyclooxygenase. Incubation of cells with catalase (5 U/ml) protected against the O/sub 3/-induced depression in PGl/sub 2/ synthesis. Exogenously added H/sub 2/O/sub 2/ (greater than or equal to 75 ..mu..M) caused a stimulation of basal PGl/sub 2/ production but depressed arachidonate-stimulated synthesis. O/sub 3/ exposure (2 hr, 1.0 ppm) produced altered metabolism of arachidonate in other important lung cell types, e.g., a decreased PGl/sub 2/ synthesis in smooth muscle cultures. Exposure of lung macrophages to O/sub 3/ caused an increase in almost all arachidonate metabolites produced.

  7. Asiatic acid uncouples respiration in isolated mouse liver mitochondria and induces HepG2 cells death.

    PubMed

    Lu, Yapeng; Liu, Siyuan; Wang, Ying; Wang, Dang; Gao, Jing; Zhu, Li

    2016-09-01

    Asiatic acid, one of the triterpenoid components isolated from Centella asiatica, has received increasing attention due to a wide variety of biological activities. To date, little is known about its mechanisms of action. Here we examined the cytotoxic effect of asiatic acid on HepG2 cells and elucidated some of the underlying mechanisms. Asiatic acid induced rapid cell death, as well as mitochondrial membrane potential (MMP) dissipation, ATP depletion and cytochrome c release from mitochondria to the cytosol in HepG2 cells. In mitochondria isolated from mouse liver, asiatic acid treatment significantly stimulated the succinate-supported state 4 respiration rate, dissipated the MMP, increased Ca(2+) release from Ca(2+)-loaded mitochondria, decreased ATP content and promoted cytochrome c release, indicating the uncoupling effect of asiatic acid. Hydrogen peroxide (H2O2) produced by succinate-supported mitochondrial respiration was also significantly inhibited by asiatic acid. In addition, asiatic acid inhibited Ca(2+)-induced mitochondrial swelling but did not induce mitochondrial swelling in hyposmotic potassium acetate medium which suggested that asiatic acid may not act as a protonophoric uncoupler. Inhibition of uncoupling proteins (UCPs) or blockade of adenine nucleotide transporter (ANT) attenuated the effect of asiatic acid on MMP dissipation, Ca(2+) release, mitochondrial respiration and HepG2 cell death. When combined inhibition of UCPs and ANT, asiatic acid-mediated uncoupling effect was noticeably alleviated. These results suggested that both UCPs and ANT partially contribute to the uncoupling properties of asiatic acid. In conclusion, asiatic acid is a novel mitochondrial uncoupler and this property is potentially involved in its toxicity on HepG2 cells. PMID:27288117

  8. Hyaluronic acid influence on platelet-induced airway smooth muscle cell proliferation

    SciTech Connect

    Svensson Holm, Ann-Charlotte B.; Bengtsson, Torbjoern; Grenegard, Magnus; Lindstroem, Eva G.

    2012-03-10

    Hyaluronic acid (HA) is one of the main components of the extracellular matrix (ECM) and is expressed throughout the body including the lung and mostly in areas surrounding proliferating and migrating cells. Furthermore, platelets have been implicated as important players in the airway remodelling process, e.g. due to their ability to induce airway smooth muscle cell (ASMC) proliferation. The aim of the present study was to investigate the role of HA, the HA-binding surface receptor CD44 and focal adhesion kinase (FAK) in platelet-induced ASMC proliferation. Proliferation of ASMC was measured using the MTS-assay, and we found that the CD44 blocking antibody and the HA synthase inhibitor 4-Methylumbelliferone (4-MU) significantly inhibited platelet-induced ASMC proliferation. The interaction between ASMC and platelets was studied by fluorescent staining of F-actin. In addition, the ability of ASMC to synthesise HA was investigated by fluorescent staining using biotinylated HA-binding protein and a streptavidin conjugate. We observed that ASMC produced HA and that a CD44 blocking antibody and 4-MU significantly inhibited platelet binding to the area surrounding the ASMC. Furthermore, the FAK-inhibitor PF 573228 inhibited platelet-induced ASMC proliferation. Co-culture of ASMC and platelets also resulted in increased phosphorylation of FAK as detected by Western blot analysis. In addition, 4-MU significantly inhibited the increased FAK-phosphorylation. In conclusion, our findings demonstrate that ECM has the ability to influence platelet-induced ASMC proliferation. Specifically, we propose that HA produced by ASMC is recognised by platelet CD44. The platelet/HA interaction is followed by FAK activation and increased proliferation of co-cultured ASMC. We also suggest that the mitogenic effect of platelets represents a potential important and novel mechanism that may contribute to airway remodelling.

  9. Alpha-lipoic acid enhances DMSO-induced cardiomyogenic differentiation of P19 cells.

    PubMed

    Shen, Xinghua; Yang, Qinghui; Jin, Peng; Li, Xueqi

    2014-09-01

    Alpha-lipoic acid (α-LA) is a potent antioxidant that acts as an essential cofactor in mitochondrial dehydrogenase reactions. α-LA has been shown to possess anti-inflammatory and cytoprotective properties, and is used to improve symptoms of diabetic neuropathy. However, the role of α-LA in stem cell differentiation and the underlying molecular mechanisms remain unknown. In the present study, we showed that α-LA significantly promoted dimethyl sulfoxide (DMSO)-induced cardiomyogenic differentiation of mouse embryonic carcinoma P19 cells. α-LA dose dependently increased beating embryonic body (EB) percentages of DMSO-differentiated P19 cells. The expressions of cardiac specific genes TNNT2, Nkx2.5, GATA4, MEF2C, and MLC2V and cardiac isoform of troponin T (cTnT)-positively stained cell population were significantly up-regulated by the addition of α-LA. We also demonstrated that the differentiation time after EB formation was critical for α-LA to take effect. Interestingly, without DMSO treatment, α-LA did not stimulate the cardiomyogenic differentiation of P19 cells. Further investigation indicated that collagen synthesis-enhancing activity, instead of the antioxidative property, plays a significant role in the cardiomyogenic differentiation-promoting function of α-LA. These findings highlight the potential use of α-LA for regenerative therapies in heart diseases. PMID:25112287

  10. Protective effect of boric acid on lead- and cadmium-induced genotoxicity in V79 cells.

    PubMed

    Ustündağ, Aylin; Behm, Claudia; Föllmann, Wolfram; Duydu, Yalçin; Degen, Gisela H

    2014-06-01

    The toxic heavy metals cadmium (Cd) and lead (Pb) are important environmental pollutants which can cause serious damage to human health. As the metal ions (Cd(2+) and Pb(2+)) accumulate in the organism, there is special concern regarding chronic toxicity and damage to the genetic material. Metal-induced genotoxicity has been attributed to indirect mechanisms, such as induction of oxidative stress and interference with DNA repair. Boron is a naturally occurring element and considered to be an essential micronutrient, although the cellular activities of boron compounds remain largely unexplored. The present study has been conducted to evaluate potential protective effects of boric acid (BA) against genotoxicity induced by cadmium chloride (CdCl2) and lead chloride (PbCl2) in V79 cell cultures. Cytotoxicity assays (neutral red uptake and cell titer blue assay) served to determine suitable concentrations for subsequent genotoxicity assays. Chromosomal damage and DNA strand breaks were assessed by micronucleus tests and comet assays. Both PbCl2 and CdCl2 (at 3, 5 and 10 µM) were shown to induce concentration-dependent increases in micronucleus frequencies and DNA strand breaks in V79 cells. BA itself was not cytotoxic (up to 300 µM) and showed no genotoxic effects. Pretreatment of cells with low levels of BA (2.5 and 10 µM) was found to strongly reduce the genotoxic effects of the tested metals. Based on the findings of this in vitro study, it can be suggested that boron provides an efficient protection against the induction of DNA strand breaks and micronuclei by lead and cadmium. Further studies on the underlying mechanisms for the protective effect of boron are needed. PMID:24710572

  11. Role of intracellular calcium and NADPH oxidase NOX5-S in acid-induced DNA damage in Barrett's cells and Barrett's esophageal adenocarcinoma cells

    PubMed Central

    Li, Dan

    2014-01-01

    Mechanisms whereby acid reflux may accelerate the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. Acid and reactive oxygen species (ROS) have been reported to cause DNA damage in Barrett's cells. We have previously shown that NADPH oxidase NOX5-S is responsible for acid-induced H2O2 production in Barrett's cells and in EA cells. In this study we examined the role of intracellular calcium and NADPH oxidase NOX5-S in acid-induced DNA damage in a Barrett's EA cell line FLO and a Barrett's cell line CP-A. We found that pulsed acid treatment significantly increased tail moment in FLO and CP-A cells and histone H2AX phosphorylation in FLO cells. In addition, acid treatment significantly increased intracellular Ca2+ in FLO cells, an increase that is blocked by Ca2+-free medium with EGTA and thapsigargin. Acid-induced increase in tail moment was significantly decreased by NADPH oxidase inhibitor diphenylene iodonium in FLO cells, and by blockade of intracellular Ca2+ increase or knockdown of NOX5-S with NOX5 small-interfering RNA (siRNA) in FLO and CP-A cells. Acid-induced increase in histone H2AX phosphorylation was significantly decreased by NOX5 siRNA in FLO cells. Conversely, overexpression of NOX5-S significantly increased tail moment and histone H2AX phosphorylation in FLO cells. We conclude that pulsed acid treatment causes DNA damage via increase of intracellular calcium and activation of NOX5-S. It is possible that in BE acid reflux increases intracellular calcium, activates NOX5-S, and increases ROS production, which causes DNA damage, thereby contributing to the progression from BE to EA. PMID:24699332

  12. Mucosal production of uric acid by airway epithelial cells contributes to particulate matter-induced allergic sensitization.

    PubMed

    Gold, M J; Hiebert, P R; Park, H Y; Stefanowicz, D; Le, A; Starkey, M R; Deane, A; Brown, A C; Liu, G; Horvat, J C; Ibrahim, Z A; Sukkar, M B; Hansbro, P M; Carlsten, C; VanEeden, S; Sin, D D; McNagny, K M; Knight, D A; Hirota, J A

    2016-05-01

    Exposure to particulate matter (PM), a major component of air pollution, contributes to increased morbidity and mortality worldwide. PM induces innate immune responses and contributes to allergic sensitization, although the mechanisms governing this process remain unclear. Lung mucosal uric acid has also been linked to allergic sensitization. The links among PM exposure, uric acid, and allergic sensitization remain unexplored. We therefore investigated the mechanisms behind PM-induced allergic sensitization in the context of lung mucosal uric acid. PM10 and house dust mite exposure selectively induced lung mucosal uric acid production and secretion in vivo, which did not occur with other challenges (lipopolysaccharide, virus, bacteria, or inflammatory/fibrotic stimuli). PM10-induced uric acid mediates allergic sensitization and augments antigen-specific T-cell proliferation, which is inhibited by uricase. We then demonstrate that human airway epithelial cells secrete uric acid basally and after stimulation through a previously unidentified mucosal secretion system. Our work discovers a previously unknown mechanism of air pollution-induced, uric acid-mediated, allergic sensitization that may be important in the pathogenesis of asthma. PMID:26509876

  13. Modulatory Effect of Betulinic Acid on the Genotoxicity Induced by Different Mutagens in V79 Cells

    PubMed Central

    Acésio, Nathália Oliveira; de Oliveira, Pollyanna Francielli; Mastrocola, Daiane Fernanda Pereira; Lima, Ildercílio Mota de Souza; Munari, Carla Carolina; Sato, Vânia Luiza Ferreira Lucatti; Souza, Andressa Aparecida Silva; Flauzino, Lúzio Gabriel Bocalon; Cunha, Wilson Roberto; Tavares, Denise Crispim

    2016-01-01

    Betulinic acid (BA) is a pentacyclic triterpene that can be isolated from many medicinal plants around the world. The aim of this study was to evaluate the genotoxic potential of BA and its effect on the genotoxicity induced by different mutagens in V79 cells using the cytokinesis-block micronucleus assay. Different BA concentrations were combined with methyl methanesulfonate (MMS), doxorubicin (DXR), camptothecin (CPT), and etoposide (VP-16). The frequencies of micronuclei in cultures treated with different BA concentrations did not differ from those of the negative control. Treatment with BA and MMS resulted in lower micronucleus frequencies than those observed for cultures treated with MMS alone. On the other hand, a significant increase in micronucleus frequencies was observed in cultures treated with BA combined with DXR or VP-16 when compared to these mutagens alone. The results showed no effect of BA on CPT-induced genotoxicity. Therefore, BA was not genotoxic under the present experimental conditions and exerted a different influence on the genotoxicity induced by different mutagens. The modulatory effect of BA depends on the type of mutagen and concentrations used. PMID:27195016

  14. Protective Effects and Mechanisms of Salvianolic Acid B Against H₂O₂-Induced Injury in Induced Pluripotent Stem Cell-Derived Neural Stem Cells.

    PubMed

    Shu, Tao; Pang, Mao; Rong, Limin; Liu, Chang; Wang, Juan; Zhou, Wei; Wang, Xuan; Liu, Bin

    2015-06-01

    Induced pluripotent stem cells (iPSCs) have the potential to differentiate into neural lineages. Salvianolic acid B (Sal B) is a commonly used, traditional Chinese medicine for enhancing neuroprotective effects, and has antioxidant, anti-inflammatory, and antiapoptotic properties. Here, we explore the potential mechanism of Sal B in protecting iPSC-derived neural stem cells (NSCs) against H2O2-induced injury. iPSCs were induced into NSCs, iPSC-derived NSCs were treated with 50 μM Sal B for 24.5 h and 500 μM H2O2 for 24 h. The resulting effects were examined by flow cytometry analysis, quantitative reverse-transcription polymerase chain reaction, and western blotting. Upon H2O2 exposure, Sal B significantly promoted cell viability and stabilization of the mitochondrial membrane potential. Sal B also visibly decreased the cell apoptotic ratio. In addition, Sal B markedly reduced expression of matrix metalloproteinase (MMP)-2 and -9, and phosphospecific signal transducer and activator of transcription 3 (p-STAT3), and increased the level of tissue inhibitor of metalloproteinase (TIMP)-2 in iPSC-derived NSCs induced by H2O2. These results suggest that Sal B protects iPSC-derived NSCs against H2O2-induced oxidative stress. The mechanisms of this stress tolerance may be attributed to modulation of the MMP/TIMP system and inhibition of the STAT3 signaling pathway. PMID:25855584

  15. Boletus edulis ribonucleic acid - a potent apoptosis inducer in human colon adenocarcinoma cells.

    PubMed

    Lemieszek, Marta Kinga; Ribeiro, Miguel; Guichard Alves, Helena; Marques, Guilhermina; Nunes, Fernando Milheiro; Rzeski, Wojciech

    2016-07-13

    Despite the large popularity of the Boletus edulis mushroom, little is known about its influence on human health and the possibilities of its therapeutic use. Nevertheless, several reports revealed the usefulness of biopolymers isolated from it in cancer treatment. Our previous studies have shown that B. edulis water soluble biopolymers are not toxic against normal colon epithelial cells (CCD841 CoTr) and at the same concentration range elicited a very prominent antiproliferative effect in colon cancer cells (LS180) which was accompanied with cell cycle arrest in the G0/G1 phase. The purpose of the present study was to verify the proapoptotic properties of a selected fraction from B. edulis - BE3, as well as determine its chemical nature. The BE3 fraction was extracted with hot water and purified by anion-exchange chromatography. Further chemical examinations revealed that BE3 consists mainly of ribonucleic acid (59.1%). The ability of BE3 to induce programmed cell death was examined in human colon cancer cell lines LS180 and HT-29 by measuring caspase activation, DNA fragmentation and expression of BAX, BCL2, TP53 and CDKN1A genes. The sensitivity of colon cancer cells with silenced BAX, TP53 and CDKN1A expression to BE3 treatment was also evaluated. We have demonstrated for the first time that the BE3 fraction is a potent apoptosis inducer in human colon cancer cells. The revealed mechanism of apoptosis triggering was dependent on the presence of functional p53 and consequently was a little different in investigated cell lines. Our results indicated that BE3 stimulated proapoptotic genes BAX (LS180, HT-29), TP53 (LS180) and CDKN1A (HT-29) while at the same time silenced the expression of the key prosurvival gene BCL2 (LS180, HT-29). The obtained results indicate the high therapeutic potential of the BE3 fraction against colon cancer, yet it is necessary to further confirm fraction efficacy and safety in animal and clinical studies. PMID:27302173

  16. Rho Kinase ROCK2 Mediates Acid-Induced NADPH Oxidase NOX5-S Expression in Human Esophageal Adenocarcinoma Cells

    PubMed Central

    Cao, Weibiao

    2016-01-01

    Mechanisms of the progression from Barrett’s esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. We have shown that NOX5-S may be involved in this progression. However, how acid upregulates NOX5-S is not well known. We found that acid-induced increase in NOX5-S expression was significantly decreased by the Rho kinase (ROCK) inhibitor Y27632 in BE mucosal biopsies and FLO-1 EA cells. In addition, acid treatment significantly increased the Rho kinase activity in FLO-1 cells. The acid-induced increase in NOX5-S expression and H2O2 production was significantly decreased by knockdown of Rho kinase ROCK2, but not by knockdown of ROCK1. Conversely, the overexpression of the constitutively active ROCK2, but not the constitutively active ROCK1, significantly enhanced the NOX5-S expression and H2O2 production. Moreover, the acid-induced increase in Rho kinase activity and in NOX5-S mRNA expression was blocked by the removal of calcium in both FLO-1 and OE33 cells. The calcium ionophore A23187 significantly increased the Rho kinase activity and NOX5-S mRNA expression. We conclude that acid-induced increase in NOX5-S expression and H2O2 production may depend on the activation of ROCK2, but not ROCK1, in EA cells. The acid-induced activation of Rho kinase may be mediated by the intracellular calcium increase. It is possible that persistent acid reflux present in BE patients may increase the intracellular calcium, activate ROCK2 and thereby upregulate NOX5-S. High levels of reactive oxygen species derived from NOX5-S may cause DNA damage and thereby contribute to the progression from BE to EA. PMID:26901778

  17. Taurochenodeoxycholic acid induces NR8383 cells apoptosis via PKC/JNK-dependent pathway.

    PubMed

    Wang, Xu; Zhang, Ziying; He, Xiuling; Mao, Wei; Zhou, Lei; Li, Peifeng

    2016-09-01

    Our former studies have suggested that taurochenodeoxycholic acid (TCDCA) as a signaling molecule shows obvious anti-inflammatory and immune regulation properties. In this research, we tentatively explored the potential effects and the possible mechanism that involve in the apoptotic process in NR8383 cells induced by TCDCA. Using flow cytometry analysis, we evaluated the apoptosis rate. Gene expression levels were determined by qPCR. The expressions of protein kinase C (PKC), Jun N-terminal kinase (JNK) and their phosphorylation were measured by Western Blot. We observed the activities of caspase-3 and caspase-8 with Caspase-Glo® regent. The results demonstrated that TCDCA dramatically improved the apoptosis rate of NR8383 cells in a concentration-dependent manner. In the meantime, PKC mRNA levels and activities were significantly augmented by TCDCA treatments. In addition, JNK, caspase-3 and caspase-8 mRNA expression levels and activities were increased by TCDCA, while they were markedly decreased by specific inhibitors. We conclude that TCDCA contributes to the apoptosis through the activation of the caspase cascade in NR8383 cells, and the PKC/JNK signaling pathway may be involved in this process. These results indicate that TCDCA may be a latent effective pharmaceutical product for apoptosis-related diseases. PMID:27268718

  18. Involvement of apoptotic cell death and cell cycle perturbation in retinoic acid-induced cleft palate in mice

    SciTech Connect

    Okano, Junko . E-mail: okajun@anat1.med.kyoto-u.ac.jp; Suzuki, Shigehiko; Shiota, Kohei

    2007-05-15

    Retinoic acid (RA), a metabolite of vitamin A, plays a key role in a variety of biological processes and is essential for normal embryonic development. On the other hand, exogenous RA could cause cleft palate in offspring when it is given to pregnant animals at either the early or late phases of palatogenesis, but the pathogenetic mechanism of cleft palate caused by excess RA remains not fully elucidated. The aim of the present study was to investigate the effects of excess of RA on early palatogenesis in mouse fetuses and analyze the teratogenic mechanism, especially at the stage prior to palatal shelf elevation. We gave all-trans RA (100 mg/kg) orally to E11.5 ICR pregnant mice and observed the changes occurring in the palatal shelves of their fetuses. It was found that apoptotic cell death increased not only in the epithelium of the palatal shelves but also in the tongue primordium, which might affect tongue withdrawal movement during palatogenesis and impair the horizontal elevation of palatal shelves. In addition, RA was found to prevent the G{sub 1}/S progression of palatal mesenchymal cells through upregulation of p21 {sup Cip1}, leading to Rb hypophospholylation. Thus, RA appears to cause G{sub 1} arrest in palatal mesenchymal cells in a similar manner as in various cancer and embryonic cells. It is likely that apoptotic cell death and cell cycle disruption are involved in cleft palate formation induced by RA.

  19. Interaction between abscisic acid and nitric oxide in PB90-induced catharanthine biosynthesis of catharanthus roseus cell suspension cultures.

    PubMed

    Chen, Qian; Chen, Zunwei; Lu, Li; Jin, Haihong; Sun, Lina; Yu, Qin; Xu, Hongke; Yang, Fengxia; Fu, Mengna; Li, Shengchao; Wang, Huizhong; Xu, Maojun

    2013-01-01

    Elicitations are considered to be an important strategy to improve production of secondary metabolites of plant cell cultures. However, mechanisms responsible for the elicitor-induced production of secondary metabolites of plant cells have not yet been fully elucidated. Here, we report that treatment of Catharanthus roseus cell suspension cultures with PB90, a protein elicitor from Phytophthora boehmeriae, induced rapid increases of abscisic acid (ABA) and nitric oxide (NO), subsequently followed by the enhancement of catharanthine production and up-regulation of Str and Tdc, two important genes in catharanthine biosynthesis. PB90-induced catharanthine production and the gene expression were suppressed by the ABA inhibitor and NO scavenger respectively, showing that ABA and NO are essential for the elicitor-induced catharanthine biosynthesis. The relationship between ABA and NO in mediating catharanthine biosynthesis was further investigated. Treatment of the cells with ABA triggered NO accumulation and induced catharanthine production and up-regulation of Str and Tdc. ABA-induced catharanthine production and gene expressions were suppressed by the NO scavenger. Conversely, exogenous application of NO did not stimulate ABA generation and treatment with ABA inhibitor did not suppress NO-induced catharanthine production and gene expressions. Together, the results showed that both NO and ABA were involved in PB90-induced catharanthine biosynthesis of C. roseus cells. Furthermore, our data demonstrated that ABA acted upstream of NO in the signaling cascade leading to PB90-induced catharanthine biosynthesis of C. roseus cells. PMID:23554409

  20. Acidic leucine-rich nuclear phosphoprotein 32 family member B (ANP32B) contributes to retinoic acid-induced differentiation of leukemic cells

    SciTech Connect

    Yu, Yun; Shen, Shao-Ming; Zhang, Fei-Fei; Wu, Zhao-Xia; Han, Bin; Wang, Li-Shun

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer ANP32B was down-regulated during ATRA-induced leukemic cell differentiation. Black-Right-Pointing-Pointer Knockdown of ANP32B enhanced ATRA-induced leukemic cell differentiation. Black-Right-Pointing-Pointer Ectopic expression of ANP32B inhibited ATRA-induced leukemic cell differentiation. Black-Right-Pointing-Pointer ANP32B inhibited ATRA activated transcriptional activity of RAR{alpha}. -- Abstract: The acidic leucine-rich nuclear phosphoprotein 32B (ANP32B) is a member of a conserved superfamily of nuclear proteins whose functions are largely unknown. In our previous work, ANP32B was identified as a novel direct substrate for caspase-3 and acted as a negative regulator for leukemic cell apoptosis. In this work, we provided the first demonstration that ANP32B expression was down-regulated during differentiation induction of leukemic cells by all-trans retinoic acid (ATRA). Knockdown of ANP32B expression by specific shRNA enhanced ATRA-induced leukemic cell differentiation, while ectopic expression of ANP32B attenuated it, indicating an inhibitory role of ANP32B against leukemic cell differentiation. Furthermore, luciferase reporter assay revealed that ANP32B might exert this role through inhibiting the ATRA dependent transcriptional activity of retinoic acid receptor (RAR{alpha}). These data will shed new insights into understanding the biological functions of ANP32B protein.

  1. Salicylic acid induces apoptosis in colon carcinoma cells grown in-vitro: Influence of oxygen and salicylic acid concentration

    SciTech Connect

    Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin

    2012-04-15

    In solid tumors the hypoxic environment can promote tumor progression and resistance to therapy. Recently, acetylsalicylic acid a major component of analgesic drugs and its metabolite salicylic acid (SA) have been shown to reduce the risk of colon cancer, but the mechanisms of action remain still unclear. Here we elucidate the effects of physiologically relevant concentrations of SA on colon carcinoma cells (CaCo-2) grown under normoxic and hypoxic conditions. Western blotting, caspase-3/7 apoptosis assays, MTS cell-proliferation assays, LDH cytotoxicity assays and hydrogen peroxide measurements were performed to investigate the effects of 1 and 10 {mu}M SA on CaCo-2 cells grown under normoxic conditions and cells exposed to hypoxia. Under normoxic conditions, SA did not influence cell proliferation or LDH release of CaCo-2 cells. However, caspase-3/7 activity was significantly increased. Under hypoxia, cell proliferation was reduced and LDH release and caspase-3/7 activities were increased. None of these parameters was altered by the addition of SA under hypoxic conditions. Hypoxia increased hydrogen peroxide concentrations 300-fold and SA significantly augmented the release of hydrogen peroxide under normoxic, but not under hypoxic conditions. Phosphorylation of the pro-survival kinases akt and erk1/2 was not changed by SA under hypoxic conditions, whereas under normoxia SA reduced phosphorylation of erk1/2 after 2 hours. We conclude that in colon carcinoma cells effects of SA on apoptosis and cellular signaling are dependent on the availability of oxygen. -- Highlights: Black-Right-Pointing-Pointer Effects of salicylic acid on colon carcinoma cells grown under normoxic and hypoxic conditions Black-Right-Pointing-Pointer Salicylic acid increases caspase-3/7 activity and hydrogen peroxide release under normoxia Black-Right-Pointing-Pointer Salicylic acid decreases pro-survival erk-1/2 phosphorylation under normoxia Black-Right-Pointing-Pointer Salicylic acid does

  2. Activation of p53 contributes to pseudolaric acid B-induced senescence in human lung cancer cells in vitro

    PubMed Central

    Yao, Guo-dong; Yang, Jing; Li, Qiang; Zhang, Ye; Qi, Min; Fan, Si-miao; Hayashi, Toshihiko; Tashiro, Shin-ichi; Onodera, Satoshi; Ikejima, Takashi

    2016-01-01

    Aim: Pseudolaric acid B (PAB), a diterpene acid isolated from the root bark of Pseudolarix kaempferi Gordon, has shown to exert anti-tumor effects via inducing cell cycle arrest followed by apoptosis in several cancer cell lines. Here we reported that PAB induced a mitotic catastrophe in human lung cancer A549 cells, which resulted in senescence without apoptosis or necrosis. Methods: Three human lung cancer cell lines (A549, H460 and H1299 cells) were examined. Cell growth inhibition was assessed with MTT assay. Cell cycle distribution was determined using a flow cytometer. Cell nuclear morphology was observed under a fluorescence microscope. Senescent cells were detected using SA-β-Gal staining. Apoptotic and senescent protein expression was examined using Western blot analysis. The expression of p53 and p21 in the cells was downregulated by siRNAs. Results: Treatment with PAB (5–80 μmol/L) inhibited the growth of A549 cells in dose- and time-dependent manners. Prolonged treatment with PAB (20 μmol/L) caused G2/M arrest at day 1 followed by mitotic catastrophe from day 2, which eventually resulted in cell senescence between days 3 and 4 without cell death (apoptosis or necrosis). Knockdown of p53 expression with siRNA significantly suppressed PAB-induced senescence in A549 cells (p53 wild). Furthermore, PAB-induced senescence was also observed in human lung cancer H460 cells (p53 wild), but not in human lung cancer H1299 cells (p53 null). Conclusion: The anti-tumor action of PAB against human lung cancer A549 cells in vitro involves the induction of senescence through activation of the p53 pathway. PMID:27041461

  3. [Accumulation of porphyrins in cells of system of blood induced by 5-aminolaevulinic acid].

    PubMed

    Lobanok, E S; Vasilevich, I B; Vorobeĭ, A V

    2011-01-01

    The levels and rates of accumulation of porphyrins in lymphoid cells and bone marrow cells treated with exogenous 5-aminolaevulinic acid (ALA) were studied. The dependence of the quantity of porphyrins accumulated in cell on ALA concentrations in the medium had maximum at 0.7-1.0 mM ALA for all the cell types studied (splenocytes, thymocytes, peripheral blood lymphocytes and bone marrow cells). The rate of accumulation of uro-, copro- and protoporphyrins depended on cell types. The lowest and the highest levels were found in splenocytes and highest in bone marrow cells respectively. It is suggested that photodynamic therapy employing ALA is potentially dangerous for blood cells. PMID:21870605

  4. Eicosapentaenoic acid induced SKOV-3 cell apoptosis through ERK1/2-mTOR-NF-κB pathways.

    PubMed

    Han, Lirong; Zhang, Yuanyuan; Meng, Meng; Cheng, Dai; Wang, Chunling

    2016-08-01

    Eicosapentaenoic acid (EPA), a typical kind of n-3 polyunsaturated fatty acids, has been considered to be a potent antitumor adjuvant. However, the mechanism related to EPA-induced SKOV-3 cell apoptosis has not been investigated. In this study, we elucidated the anticancer effect of EPA on SKOV-3 cells and its molecular mechanisms. The results of fluorescence microscopy showed that EPA induced typical apoptotic morphological features in SKOV-3 cells. Flow cytometric analysis indicated that EPA induced apoptosis of SKOV-3 cells through cells arrested at the S phase. Western blotting results showed that EPA could inhibit the phosphorylation of ERK1/2 and Akt, which restrained mammalian target of rapamycin (mTOR) phosphorylated. Simultaneously, EPA downregulated the phosphorylation status of mTOR, which may act as an upstream regulator of EPA-blocked nuclear factor κB (NF-κB) p65 translocation from the cytoplasm into the nucleus; the apoptotic mechanism of SKOV-3 cells induced by EPA was associated with the release of cytochrome c, Bax-to-Bcl-2 expression ratio, and activation of caspase-3 and caspase-9. The results suggested that EPA induced SKOV-3 cell apoptosis through ERK1/2, Akt-mTOR-NF-κB pathways. PMID:27176035

  5. Retinoic acid induces nuclear accumulation of Raf1 during differentiation of HL-60 cells

    SciTech Connect

    Smith, James; Bunaciu, Rodica P.; Reiterer, Gudrun; Coder, David; George, Thaddeus; Asaly, Michael; Yen, Andrew

    2009-08-01

    All trans-retinoic acid (RA) is a standard therapeutic agent used in differentiation induction therapy treatment of acute promyelocytic leukemia (APL). RA and its metabolites use a diverse set of signal transduction pathways during the differentiation program. In addition to the direct transcriptional targets of the nuclear RAR and RXR receptors, signals derived from membrane receptors and the Raf-MEK-ERK pathway are required. Raf1 phosphorylation and the prolonged activation of Raf1 persisting during the entire differentiation process are required for RA-dependent differentiation of HL-60 cells. Here we identify a nuclear redistribution of Raf1 during the RA-induced differentiation of HL-60 cells. In addition, the nuclear accumulation of Raf1 correlates with an increase in Raf1 phosphorylated at serine 621. The serine 621 phosphorylated Raf1 is predominantly localized in the nucleus. The RA-dependent nuclear accumulation of Raf1 suggests a novel nuclear role for Raf1 during the differentiation process.

  6. Epigenomic reorganization of the clustered Hox genes in embryonic stem cells induced by retinoic acid.

    PubMed

    Kashyap, Vasundhra; Gudas, Lorraine J; Brenet, Fabienne; Funk, Patricia; Viale, Agnes; Scandura, Joseph M

    2011-02-01

    Retinoic acid (RA) regulates clustered Hox gene expression during embryogenesis and is required to establish the anterior-posterior body plan. Using mutant embryonic stem cell lines deficient in the RA receptor γ (RARγ) or Hoxa1 3'-RA-responsive element, we studied the kinetics of transcriptional and epigenomic patterning responses to RA. RARγ is essential for RA-induced Hox transcriptional activation, and deletion of its binding site in the Hoxa1 enhancer attenuates transcriptional and epigenomic activation of both Hoxa and Hoxb gene clusters. The kinetics of epigenomic reorganization demonstrate that complete erasure of the polycomb repressive mark H3K27me3 is not necessary to initiate Hox transcription. RARγ is not required to establish the bivalent character of Hox clusters, but RA/RARγ signaling is necessary to erase H3K27me3 from activated Hox genes during embryonic stem cell differentiation. Highly coordinated, long range epigenetic Hox cluster reorganization is closely linked to transcriptional activation and is triggered by RARγ located at the Hoxa1 3'-RA-responsive element. PMID:21087926

  7. Streptozotocin induced activation of oxidative stress responsive splenic cell signaling pathways: Protective role of arjunolic acid

    SciTech Connect

    Manna, Prasenjit; Ghosh, Jyotirmoy; Das, Joydeep

    2010-04-15

    Present study investigates the beneficial role of arjunolic acid (AA) against the alteration in the cytokine levels and simultaneous activation of oxidative stress responsive signaling pathways in spleen under hyperglycemic condition. Diabetes was induced by injection of streptozotocin (STZ) (at a dose of 70 mg/kg body weight, injected in the tail vain). STZ administration elevated the levels of IL-2 as well as IFN-gamma and attenuated the level of TNF-alpha in the sera of diabetic animals. In addition, hyperglycemia is also associated with the increased production of intracellular reactive intermediates resulting with the elevation in lipid peroxidation, protein carbonylation and reduction in intracellular antioxidant defense. Investigating the oxidative stress responsive cell signaling pathways, increased expressions (immunoreactive concentrations) of phosphorylated p65 as well as its inhibitor protein phospho IkappaBalpha and phosphorylated mitogen activated protein kinases (MAPKs) have been observed in diabetic spleen tissue. Studies on isolated splenocytes revealed that hyperglycemia caused disruption of mitochondrial membrane potential, elevation in the concentration of cytosolic cytochrome c as well as activation of caspase 3 leading to apoptotic cell death. Histological examination revealed that diabetic induction depleted the white pulp scoring which is in agreement with the reduced immunological response. Treatment with AA prevented the hyperglycemia and its associated pathogenesis in spleen tissue. Results suggest that AA might act as an anti-diabetic and immunomodulatory agent against hyperglycemia.

  8. Oleic acid induces specific alterations in the morphology, gene expression and steroid hormone production of cultured bovine granulosa cells.

    PubMed

    Yenuganti, Vengala Rao; Viergutz, Torsten; Vanselow, Jens

    2016-06-01

    After parturition, one of the major problems related to nutritional management that is faced by the majority of dairy cows is negative energy balance (NEB). During NEB, excessive lipid mobilization takes place and hence the levels of free fatty acids, among them oleic acid, increase in the blood, but also in the follicular fluid. This accumulation can be associated with serious metabolic and reproductive disorders. In the present study, we analyzed the effects of physiological concentrations of oleic acid on cell morphology, apoptosis, necrosis, proliferation and steroid production, and on the abundance of selected transcripts in cultured bovine granulosa cells. Increasing oleic acid concentrations induced intracellular lipid droplet accumulation, thus resulting in a foam cell-like morphology, but had no effects on apoptosis, necrosis or proliferation. Oleic acid also significantly reduced the transcript abundance of the gonadotropin hormone receptors, FSHR and LHCGR, steroidogenic genes STAR, CYP11A1, HSD3B1 and CYP19A1, the cell cycle regulator CCND2, but not of the proliferation marker PCNA. In addition, treatment increased the transcript levels of the fatty acid transporters CD36 and SLC27A1, and decreased the production of 17-beta-estradiol and progesterone. From these data it can be concluded that oleic acid specifically affects morphological and physiological features and gene expression levels thus altering the functionality of granulosa cells. Suggestively, these effects might be partly due to the reduced expression of FSHR and thus the reduced responsiveness to FSH stimulation. PMID:27118706

  9. Impaired Neural Differentiation Potency by Retinoic Acid Receptor-α Pathway Defect in Induced Pluripotent Stem Cells

    PubMed Central

    Hou, Pei-Shan; Huang, Wen-Chin; Chiang, Wei; Lin, Wei-Che

    2014-01-01

    Abstract Induced pluripotent stem cells (iPSCs) are reprogrammed from somatic cells via ectopic gene expression and, similarly to embryonic stem cells (ESCs), possess powerful abilities to self-renew and differentiate into cells of various lineages. However, the neural differentiation potency of iPSCs remains unknown. In this study, we demonstrated the neural differentiation ability of iPSCs compared with ESCs using an retinoic acid (RA) induction system. The neural differentiation efficiency of iPSCs was obviously lower than that of ESCs. Retinoic acid receptor-α (RARα) was critical in the RA-induced neural differentiation of iPSCs, and the effect of RARα was confirmed by applying a specific RARα antagonist ER50891 to ESCs. These findings indicate that iPSCs do not possess the complete properties that ESCs have. PMID:25364979

  10. The omega-hydroxy palmitic acid induced apoptosis in human lung carcinoma cell lines H596 and A549.

    PubMed

    Abe, Akihisa; Yamane, Mototeru; Yamada, Hiroyuki; Sugawara, Isamu

    2002-02-01

    We have found that omega-hydroxy palmitic acid (16-hydroxy palmitic acid, omega-HPA) has both cell growth inhibiting and cell death inducing actions on human lung adenosquamous carcinoma cell line H596 and adenocarcinoma cell line A549. Further, these effects were dose- and time-dependent in both cell lines. However, in squamous carcinoma cell line H226, omega-HPA had no cytotoxic effect. On the other hand, in the human small cell lung carcinoma (SCLC) cell line H128, this compound showed weak cytotoxicity. The sensitivity toward omega-HPA was higher in H596 cells than in A549 cells. In both H596 and A549 cells, cell growth was inhibited to 24.4 and 9.4%, respectively, by treatment with 100 microM omega-HPA for 12 h. In the 24 h treatment cells, growth inhibition was increased to 100 and 38.1%, respectively. In cytotoxicity experiments, the number of dead cells increased with incubation times in the presence of omega-HPA: on three days incubation with 100 microM omega-HPA, viability was 0 and 13.5%, respectively, in H596 and A549 cells. Further, the fragmentation of DNA to oligonucleosomal-sized ladder fragments, which is an index of apoptosis, was observed in both cell lines on treatment with omega-HPA. Therefore, it is assumed that these cell deaths induced by omega-HPA, were apoptosis in these cell lines. Since the number of dead cells following treatment with omega-HPA decreased by treatment with omega-HPA in combination with Z-VAD-fmk, a caspase family inhibitor, it is thought that apoptotic cell death was related to caspase activity. PMID:12186781

  11. Gallic acid as a selective anticancer agent that induces apoptosis in SMMC-7721 human hepatocellular carcinoma cells

    PubMed Central

    SUN, GUOJUN; ZHANG, SHUQIN; XIE, YANRU; ZHANG, ZIYU; ZHAO, WENJING

    2016-01-01

    Gallic acid (3,4,5-trihydroxybenzoic acid; GA) is a naturally occurring plant polyphenol, isolated from water caltrop, which has been reported to exert anticancer effects. The present study investigated the antiproliferative effects of GA on the HepG2 and SMMC-7721 human hepatocellular carcinoma (HCC) cell lines using MTT and colony formation assays. In particular, the underlying mechanism of GA-induced apoptosis in SMMC-7721 cells was studied in vitro by flow cytometry and western blotting. The results of the present study indicated that GA was capable of inhibiting the proliferation of HepG2 and SMMC-7721 cells in a time- and dose-dependent manner, as well as inducing the apoptosis of SMMC-7721 cells. GA induced caspase-3, caspase-9 and reactive oxygen species activity, elevated the expression of apoptosis regulator Bcl-2-like protein 4 and reduced the mitochondrial membrane potential in SMMC-7721 cells. When compared with HL-7702 normal human hepatocytes, GA demonstrated selective toxicity for HCC cells. In conclusion, GA is able to induce apoptosis in SMMC-7721 cells in vitro via mitochondrial-mediated pathways, and may possess the potential to be a novel therapeutic compound for use in the treatment of HCC. PMID:26870182

  12. Kinase Signaling in Apoptosis Induced by Saturated Fatty Acids in Pancreatic β-Cells.

    PubMed

    Šrámek, Jan; Němcová-Fürstová, Vlasta; Kovář, Jan

    2016-01-01

    Pancreatic β-cell failure and death is considered to be one of the main factors responsible for type 2 diabetes. It is caused by, in addition to hyperglycemia, chronic exposure to increased concentrations of fatty acids, mainly saturated fatty acids. Molecular mechanisms of apoptosis induction by saturated fatty acids in β-cells are not completely clear. It has been proposed that kinase signaling could be involved, particularly, c-Jun N-terminal kinase (JNK), protein kinase C (PKC), p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK), and Akt kinases and their pathways. In this review, we discuss these kinases and their signaling pathways with respect to their possible role in apoptosis induction by saturated fatty acids in pancreatic β-cells. PMID:27626409

  13. Cellular responses induced in vitro by pestheic acid, a fungal metabolite, in a gastric adenocarcinoma cell line (PG100).

    PubMed

    Sousa, J M C; Matos, L A; Alcântara, D F A; Ribeiro, H F; Santos, L S; Oliveira, M N; Brito-Junior, L C; Khayat, A S; Guimarães, A C; Cunha, L A; Burbano, R R; Bahia, M O

    2013-01-01

    There is a constant search for new cancer treatments that are less aggressive and economically affordable. In this context, natural products extracted from plants, fungi, and microorganisms are of great interest. Pestheic acid, or dihidromaldoxin, is a chlorinated diphenylic ether extracted from the phytopathogenic fungus Pestalotiopsis guepinii (Amphisphaeriaceae). We assessed the cytotoxic, cytostatic, and genotoxic effects of pestheic acid in a gastric adenocarcinoma cell line (PG100). A decrease in clonogenic survival was observed. Pestheic acid also induced significant increases in both micronucleus and nucleoplasmic bridge frequency. However, we did not observe changes in cell cycle kinetics or apoptosis induction. Reactive oxygen species induced by diphenylic ethers may explain the genotoxicity and mutagenicity of pestheic acid. The absence of repair checkpoints that we observed is probably due to the fact that the PG100 cell line lacks the TP53 gene, which is common in gastric cancers. Even though pestheic acid has had a clear cytotoxic effect, the minimal inhibitory concentration was high, which shows that pestheic acid is not an active anticancer compound under these conditions. PMID:24114206

  14. Effect of Marine Omega 3 Fatty Acids on Methylmercury-Induced Toxicity in Fish and Mammalian Cells In Vitro

    PubMed Central

    Nøstbakken, O. J.; Bredal, I. L.; Olsvik, P. A.; Huang, T. S.; Torstensen, B. E.

    2012-01-01

    Methylmercury (MeHg) is a ubiquitous environmental contaminant which bioaccumulates in marine biota. Fish constitute an important part of a balanced human diet contributing with health beneficial nutrients but may also contain contaminants such as MeHg. Interactions between the marine n-3 fatty acids eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) with MeHg-induced toxicity were investigated. Different toxic and metabolic responses were studied in Atlantic salmon kidney (ASK) cell line and the mammalian kidney-derived HEK293 cell line. Both cell lines were preincubated with DHA or EPA prior to MeHg-exposure, and cell toxicity was assessed differently in the cell lines by MeHg-uptake in cells (ASK and HEK293), proliferation (HEK293 and ASK), apoptosis (ASK), oxidation of the red-ox probe roGFP (HEK293), and regulation of selected toxicological and metabolic transcriptional markers (ASK). DHA was observed to decrease the uptake of MeHg in HEK293, but not in ASK cells. DHA also increased, while EPA decreased, MeHg-induced apoptosis in ASK. MeHg exposure induced changes in selected metabolic and known MeHg biomarkers in ASK cells. Both DHA and MeHg, but not EPA, oxidized roGFP in HEK293 cells. In conclusion, marine n-3 fatty acids may ameliorate MeHg toxicity, either by decreasing apoptosis (EPA) or by reducing MeHg uptake (DHA). However, DHA can also augment MeHg toxicity by increasing oxidative stress and apoptosis when combined with MeHg. PMID:22654480

  15. Betulinic Acid Inhibits Growth of Cultured Vascular Smooth Muscle Cells In Vitro by Inducing G1 Arrest and Apoptosis

    PubMed Central

    Vadivelu, Raja Kumar; Yeap, Swee Keong; Ali, Abdul Manaf; Hamid, Muhajir; Alitheen, Noorjahan Banu

    2012-01-01

    Betulinic acid is a widely available plant-derived triterpene which is reported to possess selective cytotoxic activity against cancer cells of neuroectodermal origin and leukemia. However, the potential of betulinic acid as an antiproliferative and cytotoxic agent on vascular smooth muscle (VSMC) is still unclear. This study was carried out to demonstrate the antiproliferative and cytotoxic effect of betulinic acid on VSMCs using 3-[4,5-dimethylthizol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry cell cycle assay, BrdU proliferation assay, acridine orange/propidium iodide staining, and comet assay. Result from MTT and BrdU assays indicated that betulinic acid was able to inhibit the growth and proliferation of VSMCs in a dose-dependent manner with IC50 of 3.8 μg/mL significantly (P < 0.05). Nevertheless, betulinic acid exhibited G1 cell cycle arrest in flow cytometry cell cycle profiling and low level of DNA damage against VSMC in acridine orange/propidium iodide and comet assay after 24 h of treatment. In conclusion, betulinic acid induced G1 cell cycle arrest and dose-dependent DNA damage on VSMC. PMID:23056140

  16. Eicosapentaenoic acid attenuates dexamethasome-induced apoptosis by inducing adaptive autophagy via GPR120 in murine bone marrow-derived mesenchymal stem cells

    PubMed Central

    Gao, B; Han, Y-H; Wang, L; Lin, Y-J; Sun, Z; Lu, W-G; Hu, Y-Q; Li, J-Q; Lin, X-S; Liu, B-H; Jie, Q; Yang, L; Luo, Z-J

    2016-01-01

    Long-term use of glucocorticoids is a widespread clinical problem, which currently has no effective solution other than discontinuing the use. Eicosapentaenoic acid (EPA), an omega-3 long chain polyunsaturated fatty acid (n-3 PUFA), which is largely contained in fish or fish oil, has been reported to promote cell viability and improve bone metabolism. However, little is known about the effects of EPA on dexamethasome (Dex)-induced cell apoptosis. In this study, we showed that EPA-induced autophagy of murine bone marrow-derived mesenchymal stem cells (mBMMSCs). Meanwhile, EPA, but not arachidonic acid (AA), markedly inhibited Dex-induced apoptosis and promoted the viability of mBMMSCs. We also observed that EPA-induced autophagy was modulated by GPR120, but not GPR40. Further experiments showed that the mechanism of EPA-induced autophagy associated with GPR120 modulation involved an increase in the active form of AMP-activated protein kinase and a decrease in the activity of mammalian target of RAPA. The protective effect of EPA on Dex-induced apoptosis via GPR120-meditated induction of adaptive autophagy was supported by in vivo experiments. In summary, our findings may have important implications in developing future strategies to use EPA in the prevention and therapy of the side effects induced by long-term Dex-abuse. PMID:27228350

  17. Eicosapentaenoic acid attenuates dexamethasome-induced apoptosis by inducing adaptive autophagy via GPR120 in murine bone marrow-derived mesenchymal stem cells.

    PubMed

    Gao, B; Han, Y-H; Wang, L; Lin, Y-J; Sun, Z; Lu, W-G; Hu, Y-Q; Li, J-Q; Lin, X-S; Liu, B-H; Jie, Q; Yang, L; Luo, Z-J

    2016-01-01

    Long-term use of glucocorticoids is a widespread clinical problem, which currently has no effective solution other than discontinuing the use. Eicosapentaenoic acid (EPA), an omega-3 long chain polyunsaturated fatty acid (n-3 PUFA), which is largely contained in fish or fish oil, has been reported to promote cell viability and improve bone metabolism. However, little is known about the effects of EPA on dexamethasome (Dex)-induced cell apoptosis. In this study, we showed that EPA-induced autophagy of murine bone marrow-derived mesenchymal stem cells (mBMMSCs). Meanwhile, EPA, but not arachidonic acid (AA), markedly inhibited Dex-induced apoptosis and promoted the viability of mBMMSCs. We also observed that EPA-induced autophagy was modulated by GPR120, but not GPR40. Further experiments showed that the mechanism of EPA-induced autophagy associated with GPR120 modulation involved an increase in the active form of AMP-activated protein kinase and a decrease in the activity of mammalian target of RAPA. The protective effect of EPA on Dex-induced apoptosis via GPR120-meditated induction of adaptive autophagy was supported by in vivo experiments. In summary, our findings may have important implications in developing future strategies to use EPA in the prevention and therapy of the side effects induced by long-term Dex-abuse. PMID:27228350

  18. Gallic acid induces mitotic catastrophe and inhibits centrosomal clustering in HeLa cells.

    PubMed

    Tan, Si; Guan, Xin; Grün, Christoph; Zhou, Zhiqin; Schepers, Ute; Nick, Peter

    2015-12-25

    Cancer cells divide rapidly, providing medical targets for anticancer agents. The polyphenolic gallic acid (GA) is known to be toxic for certain cancer cells. However, the cellular mode of action has not been elucidated. Therefore, the current study addressed a potential effect of GA on the mitosis of cancer cells. GA inhibited viability of HeLa cells in a dose-dependent and time-dependent manner. We could show, using fluorescence-activated cell sorting (FACS), that this inhibition was accompanied by elevated frequency of cells arrested at the G2/M transition. This cell-cycle arrest was accompanied by mitotic catastrophe, and formation of cells with multiple nuclei. These aberrations were preceded by impaired centrosomal clustering. We arrive at a model of action, where GA inhibits the progression of the cell cycle at the G2/M phase by impairing centrosomal clustering which will stimulate mitotic catastrophe. Thus, GA has potential as compound against cervical cancer. PMID:26368671

  19. Bleb formation is induced by alkaline but not acidic pH in estrogen receptor silenced breast cancer cells.

    PubMed

    Khajah, Maitham A; Mathew, Princy M; Alam-Eldin, Nada S; Luqmani, Yunus A

    2015-04-01

    De novo and acquired resistance to endocrine-based therapies in breast cancer occurs in parallel with epithelial to mesenchymal transition (EMT), which is associated with enhanced proliferative and metastatic potential, and poor clinical outcome. We have established several endocrine insensitive breast cancer lines by shRNA-induced depletion of estrogen receptor (ER) by transfection of MCF7 cells. All of these exhibit EMT. We have previously reported that brief exposure of specifically ER- breast cancer cells, to extracellular alkaline pH, results in cell rounding and segregation, and leads to enhanced invasive potential. In this study we describe more detailed morphological changes and compare these with cell exposure to acidic pH. Morphological changes and localization of various molecules critical for cell adhesion and motility, associated with pH effects, were assessed by live cell microscopy, electron microscopy, and immunofluorescence. Exposure of either ER- or ER+ breast cancer cells to extracellular acidic pH did not induce significant changes in morphological appearance. Conversely, brief exposure of specifically ER silenced cells, to alkaline pH, resulted in cell contractolation and formation of bleb-like actin-rich structures which were evenly distributed on the outer membrane. Integrin α2, FAK, and JAM-1 were found in the cytoplasm streaming into the newly formed blebs. These blebs appear to be related to cell polarity and movement. Pre-treatment with cytochalasin-D or inhibitors of Rho or MLCK prevented both contractolation and bleb formation. Our data suggest that the effect of pH on the microenvironment of endocrine resistant breast cancer cells needs to be more extensively investigated. Alkaline, rather than acidic pH, appears to induce dramatic morphological changes, and enhances their invasive capabilities, through re-organization of cortical actin. PMID:25672508

  20. Dehydroascorbic acid-induced endoplasmic reticulum stress and leptin resistance in neuronal cells.

    PubMed

    Thon, Mina; Hosoi, Toru; Ozawa, Koichiro

    2016-09-16

    Due to its anti-obesity effects, an adipocyte-derived hormone, leptin, has become important for the treatment of obesity. However, most obese subjects are in a state of leptin resistance, and endoplasmic reticulum (ER) stress is suggested to be involved in the pathophysiology of leptin resistance. Dehydroascorbic acid (DHAA), an oxidized form of vitamin C, was found to be increased in diabetes. In the present study, we investigated the possible effects of DHAA on the activation of ER stress and leptin resistance. A human neuroblastoma cell line, stably transfected with the Ob-Rb leptin receptor (SH-SY5Y-ObRb), was treated with DHAA. We found that DHAA upregulated ER stress-related genes such as GRP78, CHOP, and spliced XBP1. Moreover, leptin-induced STAT3 phosphorylation was hindered by DHAA. These results suggested that increases in the levels of DHAA might be harmful to neurons, contributing to defective leptin-responsive signaling. PMID:27498033

  1. Salicylic acid induced cysteine protease activity during programmed cell death in tomato plants.

    PubMed

    Kovács, Judit; Poór, Péter; Szepesi, Ágnes; Tari, Irma

    2016-06-01

    The hypersensitive response (HR), a type of programmed cell death (PCD) during biotic stress is mediated by salicylic acid (SA). The aim of this work was to reveal the role of proteolysis and cysteine proteases in the execution of PCD in response of SA. Tomato plants were treated with sublethal (0.1 mM) and lethal (1 mM) SA concentrations through the root system. Treatment with 1 mM SA increased the electrolyte leakage and proteolytic activity and reduced the total protein content of roots after 6 h, while the proteolytic activity did not change in the leaves and in plants exposed to 0.1 mM SA. The expression of the papain-type cysteine protease SlCYP1, the vacuolar processing enzyme SlVPE1 and the tomato metacaspase SlMCA1 was induced within the first three hours in the leaves and after 0.5 h in the roots in the presence of 1 mM SA but the transcript levels did not increase significantly at sublethal SA. The Bax inhibitor-1 (SlBI-1), an antiapoptotic gene was over-expressed in the roots after SA treatments and it proved to be transient in the presence of sublethal SA. Protease inhibitors, SlPI2 and SlLTC were upregulated in the roots by sublethal SA but their expression remained low at 1 mM SA concentration. It is concluded that in contrast to leaves the SA-induced PCD is associated with increased proteolytic activity in the root tissues resulting from a fast up-regulation of specific cysteine proteases and down-regulation of protease inhibitors. PMID:27165526

  2. Aristolochic acid-induced apoptosis and G2 cell cycle arrest depends on ROS generation and MAP kinases activation.

    PubMed

    Romanov, Victor; Whyard, Terry C; Waltzer, Wayne C; Grollman, Arthur P; Rosenquist, Thomas

    2015-01-01

    Ingestion of aristolochic acids (AAs) contained in herbal remedies results in a renal disease and, frequently, urothelial malignancy. The genotoxicity of AA in renal cells, including mutagenic DNA adducts formation, is well documented. However, the mechanisms of AA-induced tubular atrophy and renal fibrosis are largely unknown. To better elucidate some aspects of this process, we studied cell cycle distribution and cell survival of renal epithelial cells treated with AAI at low and high doses. A low dose of AA induces cell cycle arrest in G2/M phase via activation of DNA damage checkpoint pathway ATM-Chk2-p53-p21. DNA damage signaling pathway is activated more likely via increased production of reactive oxygen species (ROS) caused by AA treatment then via DNA damage induced directly by AA. Higher AA concentration induced cell death partly via apoptosis. Since mitogen-activated protein kinases play an important role in cell survival, death and cell cycle progression, we assayed their function in AA-treated renal tubular epithelial cells. ERK1/2 and p38 but not JNK were activated in cells treated with AA. In addition, pharmacological inhibition of ERK1/2 and p38 as well as suppression of ROS generation with N-acetyl-L-cysteine resulted in the partial relief of cells from G2/M checkpoint and a decline of apoptosis level. Cell cycle arrest may be a mechanism for DNA repair, cell survival and reprogramming of epithelial cells to the fibroblast type. An apoptosis of renal epithelial cells at higher AA dose might be necessary to provide space for newly reprogrammed fibrotic cells. PMID:24792323

  3. Chronically Elevated Levels of Short-Chain Fatty Acids Induce T Cell-Mediated Ureteritis and Hydronephrosis.

    PubMed

    Park, Jeongho; Goergen, Craig J; HogenEsch, Harm; Kim, Chang H

    2016-03-01

    Short-chain fatty acids (SCFAs) are major products of gut microbial fermentation and profoundly affect host health and disease. SCFAs generate IL-10(+) regulatory T cells, which may promote immune tolerance. However, SCFAs can also induce Th1 and Th17 cells upon immunological challenges and, therefore, also have the potential to induce inflammatory responses. Because of the seemingly paradoxical SCFA activities in regulating T cells, we investigated, in depth, the impact of elevated SCFA levels on T cells and tissue inflammation in mice. Orally administered SCFAs induced effector (Th1 and Th17) and regulatory T cells in ureter and kidney tissues, and they induced T cell-mediated ureteritis, leading to kidney hydronephrosis (hereafter called acetate-induced renal disease, or C2RD). Kidney hydronephrosis in C2RD was caused by ureteral obstruction, which was, in turn, induced by SCFA-induced inflammation in the ureteropelvic junction and proximal ureter. Oral administration of all major SCFAs, such as acetate, propionate, and butyrate, induced the disease. We found that C2RD development is dependent on mammalian target of rapamycin activation, T cell-derived inflammatory cytokines such as IFN-γ and IL-17, and gut microbiota. Young or male animals were more susceptible than old or female animals, respectively. However, SCFA receptor (GPR41 or GPR43) deficiency did not affect C2RD development. Thus, SCFAs, when systemically administered at levels higher than physiological levels, cause dysregulated T cell responses and tissue inflammation in the renal system. The results provide insights into the immunological and pathological effects of chronically elevated SCFAs. PMID:26819206

  4. Osmotically inducible uptake of betaine via amino acid transport system A in SV-3T3 cells.

    PubMed

    Petronini, P G; De Angelis, E; Borghetti, A F; Wheeler, K P

    1994-05-15

    The osmotically inducible uptake of betaine (NNN-trimethylglycine) by SV-3T3 cells has been studied and compared with the similar process in MDCK cells. Betaine uptake by SV-3T3 cells could be described in terms of a saturable, Na(+)-dependent, component plus a small non-saturable, Na(+)-independent, component. Transport was active, producing considerable accumulation of betaine in the cells. After exposure of the cells to hypertonic conditions for 6 h, there was a marked increase in betaine uptake. Kinetic analysis indicated that this increase resulted from an increase in the Vmax. value of the saturable component, from about 88 to 185 nmol of betaine/5 min per mg of protein, the corresponding Km values of about 15 and 10 mM not being significantly different. This induction of transport activity was detectable only after about 2 h exposure of the cells to hypertonic medium, closely paralleling an induction of influx of N-methylaminoisobutyric acid, and was prevented by the presence of cycloheximide. Betaine influx was markedly inhibited by several neutral amino acids, particularly those transported by system A, such as N-methylaminoisobutyric acid and the imino acid proline. A high concentration (25 mM) of betaine also significantly inhibited the uptake of proline by SV-3T3 cells. Although very similar results were obtained with MDCK cells, prolonged exposure of cells to hypertonic conditions revealed distinct differences. When the hypertonic incubation was extended from 6 h to 24 h, betaine transport in SV-3T3 cells either remained the same or decreased, whereas it showed a further marked increase in MDCK cells, and also became sensitive to inhibition by gamma-aminobutyric acid. mRNA for the betaine transporter BGT-1 [Yamauchi, Uchida, Kwon, Preston, Brooks Robey, Garcia-Perez, Burg and Handler (1992) J. Biol. Chem. 267, 649-652] was detectable in MDCK cells exposed to hypertonic medium for 24 h, but not in SV-3T3 cells under any conditions. It is concluded that

  5. Arachidonic acid induces a prolonged inhibition of glutamate uptake into glial cells.

    PubMed

    Barbour, B; Szatkowski, M; Ingledew, N; Attwell, D

    Activation of NMDA (N-methyl-D-aspartate) receptors by neurotransmitter glutamate stimulates phospholipase A2 to release arachidonic acid. This second messenger facilitates long-term potentiation of glutamatergic synapses in the hippocampus, possibly by blocking glutamate uptake. We have studied the effect of arachidonic acid on glutamate uptake into glial cells using the whole-cell patch-clamp technique to monitor the uptake electrically. Micromolar levels of arachidonic acid inhibit glutamate uptake, mainly by reducing the maximum uptake rate with only small effects on the affinity for external glutamate and sodium. On removal of arachidonic acid a rapid (5 minutes) phase of partial recovery is followed by a maintained suppression of uptake lasting at least 20 minutes. Surprisingly, the action of arachidonic acid is unaffected by cyclo-oxygenase or lipoxygenase inhibitors suggesting that it inhibits uptake directly, possibly by increasing membrane fluidity. As blockade of phospholipase A2 prevents the induction of long-term potentiation (LTP), inhibition of glutamate uptake by arachidonic acid may contribute to the increase of synaptic gain that occurs in LTP. During anoxia, release of arachidonic acid could severely compromise glutamate uptake and thus contribute to neuronal death. PMID:2512508

  6. Retinoic acid induces homing of protective T and B cells to the gut after subcutaneous immunization in mice.

    PubMed

    Hammerschmidt, Swantje I; Friedrichsen, Michaela; Boelter, Jasmin; Lyszkiewicz, Marcin; Kremmer, Elisabeth; Pabst, Oliver; Förster, Reinhold

    2011-08-01

    Diarrheal diseases represent a major health burden in developing countries. Parenteral immunization typically does not induce efficient protection against enteropathogens because it does not stimulate migration of immune cells to the gut. Retinoic acid (RA) is critical for gut immunity, inducing upregulation of gut-homing receptors on activated T cells. In this study, we have demonstrated that RA can redirect immune responses elicited by s.c. vaccination of mice from skin-draining inguinal LNs (ingLNs) to the gut. When present during priming, RA induced robust upregulation of gut-homing receptors in ingLNs, imprinting gut-homing capacity on T cells. Concurrently, RA triggered the generation of gut-tropic IgA+ plasma cells in ingLNs and raised the levels of antigen-specific IgA in the intestinal lumen and blood. RA applied s.c. in vivo induced autonomous RA production in ingLN DCs, further driving efficient induction of gut-homing molecules on effector cells. Importantly, RA-supplemented s.c. immunization elicited a potent immune response in the small intestine that protected mice from cholera toxin–induced diarrhea and diminished bacterial loads in Peyer patches after oral infection with Salmonella. Thus, the use of RA as a gut-homing navigator represents a powerful tool to induce protective immunity in the intestine after s.c. immunization, offering what we believe to be a novel approach for vaccination against enteropathogens. PMID:21737878

  7. Arachidonic acid is involved in the regulation of hCG induced steroidogenesis in rat Leydig cells

    SciTech Connect

    Didolkar, A.K.; Sundaram, K.

    1987-07-27

    Phospholipase C (PLC), an enzyme involved in the hydrolysis of membrane phospholipid- phosphatidylinositol-bisphosphate to insositol triphosphate and diacylglycerol, and Phorbol 12, myristate 13, acetate (PMA) could significantly stimulate testosterone (T) secretion from Leydig cells. Arachidonic acid (AA) stimulated T secretion by about 2 fold. The steroidogenic effect of PLC and AA was biphasic. At low concentrations both PLC and AA augmented hCG induced T secretion, while at higher concentrations they inhibited steroid production. AA also had a biphasic effect on hCG induced cyclic AMP secretion. 5,8,11,14 Eicosatetrayenoic acid, a general inhibitor of AA metabolism, and Nordihydroguaiaretic acid, an inhibitor of the lipoxygenase pathway of AA metabolism, inhibited hCG induced T secretion while indomethacin, an inhibitor of cyclo-oxygenase pathway, had no effect on hCG induced T secretion. The authors conclude from these data that AA plays a role in the regulation of hCG induced steroidogenic responses in rat Leydig cells and that the metabolite(s) of AA that are involved are not cyclo-oxygenase products. 28 references, 4 figures, 2 tables.

  8. CYP epoxygenase metabolites of docosahexaenoic acid protect HL-1 cardiac cells against LPS-induced cytotoxicity through SIRT1

    PubMed Central

    Samokhvalov, V; Jamieson, K L; Vriend, J; Quan, S; Seubert, J M

    2015-01-01

    Bacterial LPS is an environmental toxin capable of promoting various cardiac complications. Current evidence suggests that LPS-induced myocardial dysfunction emerges as a consequence of compromised quality of cardiac mitochondria. Docosahexaenoic acid (DHA, 22:6n3) is an n-3 polyunsaturated fatty acid (PUFA), which produces a broad spectrum of intrinsic physiological effects including regulation of cell survival and death mechanisms. Although, numerous studies revealed fundamentally beneficial effects of DHA on cardiovascular system, it remains unknown whether these effects were produced by DHA or one of its possibly more potent metabolites. Emerging evidence indicates that cytochrome P450 (CYP) epoxygenase metabolites of DHA, epoxydocosapentaenoic acids (EDPs), produce more potent biological activity compared to its precursor DHA. In this study, we investigated whether DHA and its metabolite 19,20-EDP could protect HL-1 cardiac cells against LPS-induced cytotoxicity. We provide evidence that exogenously added or DHA-derived EDPs promote mitochondrial biogenesis and function in HL-1 cardiac cells. Our results illustrate the CYP epoxygenase metabolite of DHA, 19,20-EDP, confers extensive protection to HL-1 cardiac cells against LPS-induced cytotoxicity via activation of SIRT1. PMID:27182450

  9. 9-Oxo-(10E,12E)-octadecadienoic acid, a cytotoxic fatty acid ketodiene isolated from eggplant calyx, induces apoptosis in human ovarian cancer (HRA) cells.

    PubMed

    Zhao, Baiyang; Tomoda, Yutaka; Mizukami, Hajime; Makino, Toshiaki

    2015-07-01

    9-Oxo-(10E,12E)-octadecadienoic acid (9-EE-KODE), which is isolated from the calyx of eggplants, exhibits cytotoxic activity against human ovarian cancer (HRA) cells. The aim of the present study is to clarify the action mechanism of 9-EE-KODE leading to cell death. After the treatment of 9-EE-KODE in HRA cells, we found intracellular DNA fragmentation, surface-exposure of phosphatidylserine in the outer cell membrane, and increased caspase-3/7 activities in the HRA cells. The dissipation of mitochondrial membrane potential, release of cytochrome c from mitochondria to cytosol, down-regulation of Bcl-2, and up-regulation of Bax levels were also found in 9-EE-KODE-treated cells in a dose-dependent manner. These results demonstrated that 9-EE-KODE induced apoptosis in HRA cells via the mitochondrial regulation pathway. PMID:25724148

  10. Palmitic acid induces osteoblastic differentiation in vascular smooth muscle cells through ACSL3 and NF-κB, novel targets of eicosapentaenoic acid.

    PubMed

    Kageyama, Aiko; Matsui, Hiroki; Ohta, Masahiko; Sambuichi, Keisuke; Kawano, Hiroyuki; Notsu, Tatsuto; Imada, Kazunori; Yokoyama, Tomoyuki; Kurabayashi, Masahiko

    2013-01-01

    Free fatty acids (FFAs), elevated in metabolic syndrome and diabetes, play a crucial role in the development of atherosclerotic cardiovascular disease, and eicosapentaenoic acid (EPA) counteracts many aspects of FFA-induced vascular pathology. Although vascular calcification is invariably associated with atherosclerosis, the mechanisms involved are not completely elucidated. In this study, we tested the hypothesis that EPA prevents the osteoblastic differentiation and mineralization of vascular smooth muscle cells (VSMC) induced by palmitic acid (PA), the most abundant long-chain saturated fatty acid in plasma. PA increased and EPA abolished the expression of the genes for bone-related proteins, including bone morphogenetic protein (BMP)-2, Msx2 and osteopontin in human aortic smooth muscle cells (HASMC). Among the long-chain acyl-CoA synthetase (ACSL) subfamily, ACSL3 expression was predominant in HASMC, and PA robustly increased and EPA efficiently inhibited ACSL3 expression. Importantly, PA-induced osteoblastic differentiation was mediated, at least in part, by ACSL3 activation because acyl-CoA synthetase (ACS) inhibitor or siRNA targeted to ACSL3 completely prevented the PA induction of both BMP-2 and Msx2. Conversely, adenovirus-mediated ACSL3 overexpression enhanced PA-induced BMP-2 and Msx2 expression. In addition, EPA, ACSL3 siRNA and ACS inhibitor attenuated calcium deposition and caspase activation induced by PA. Notably, PA induced activation of NF-κB, and NF-κB inhibitor prevented PA-induction of osteoblastic gene expression and calcium deposition. Immunohistochemistry revealed the prominent expression of ACSL3 in VSMC and macrophages in human non-calcifying and calcifying atherosclerotic plaques from the carotid arteries. These results identify ACSL3 and NF-κB as mediators of PA-induced osteoblastic differentiation and calcium deposition in VSMC and suggest that EPA prevents vascular calcification by inhibiting such a new molecular pathway elicited

  11. Bile acid receptor TGR5, NADPH Oxidase NOX5-S and CREB Mediate Bile Acid-Induced DNA Damage In Barrett’s Esophageal Adenocarcinoma Cells

    PubMed Central

    Li, Dan; Cao, Weibiao

    2016-01-01

    The mechanisms whereby bile acid reflux may accelerate the progression from Barrett’s esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. In this study we found that bile acid taurodeoxycholic acid (TDCA) significantly increased the tail moment (TM) and histone H2AX phosphorylation in FLO-1 EA cells, an increase which was significantly decreased by knockdown of TGR5. Overexpression of TGR5 significantly increased TDCA-induced TM increase and H2AX phosphorylation. In addition, NADPH oxidase inhibitor diphenylene iodonium significantly inhibited the TDCA-induced increase in TM and H2AX phosphorylation. TDCA-induced increase in TM and H2AX phosphorylation was significantly decreased by knockdown of NOX5-S and overexpression of NOX5-S significantly increased TDCA-induced increase in the tail moment and H2AX phosphorylation. Furthermore, TDCA significantly increased cAMP response element binding protein (CREB) phosphorylation in FLO-1 cells. Knockdown of CREB significantly decreased TDCA-induced increase in NOX5-S mRNA and the tail moment. Conversely, overexpression of CREB significantly increased TDCA-induced TM increase. We conclude that TDCA-induced DNA damage may depend on the activation of TGR5, CREB and NOX5-S. It is possible that in Barrett’s patients bile acids may activate NOX5-S and increase reactive oxygen species (ROS) production via activation of TGR5 and CREB. NOX5-S-derived ROS may cause DNA damage, thereby contributing to the progression from BE to EA. PMID:27511066

  12. Bile acid receptor TGR5, NADPH Oxidase NOX5-S and CREB Mediate Bile Acid-Induced DNA Damage In Barrett's Esophageal Adenocarcinoma Cells.

    PubMed

    Li, Dan; Cao, Weibiao

    2016-01-01

    The mechanisms whereby bile acid reflux may accelerate the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. In this study we found that bile acid taurodeoxycholic acid (TDCA) significantly increased the tail moment (TM) and histone H2AX phosphorylation in FLO-1 EA cells, an increase which was significantly decreased by knockdown of TGR5. Overexpression of TGR5 significantly increased TDCA-induced TM increase and H2AX phosphorylation. In addition, NADPH oxidase inhibitor diphenylene iodonium significantly inhibited the TDCA-induced increase in TM and H2AX phosphorylation. TDCA-induced increase in TM and H2AX phosphorylation was significantly decreased by knockdown of NOX5-S and overexpression of NOX5-S significantly increased TDCA-induced increase in the tail moment and H2AX phosphorylation. Furthermore, TDCA significantly increased cAMP response element binding protein (CREB) phosphorylation in FLO-1 cells. Knockdown of CREB significantly decreased TDCA-induced increase in NOX5-S mRNA and the tail moment. Conversely, overexpression of CREB significantly increased TDCA-induced TM increase. We conclude that TDCA-induced DNA damage may depend on the activation of TGR5, CREB and NOX5-S. It is possible that in Barrett's patients bile acids may activate NOX5-S and increase reactive oxygen species (ROS) production via activation of TGR5 and CREB. NOX5-S-derived ROS may cause DNA damage, thereby contributing to the progression from BE to EA. PMID:27511066

  13. Eosinophils from Murine Lamina Propria Induce Differentiation of Naïve T Cells into Regulatory T Cells via TGF-β1 and Retinoic Acid

    PubMed Central

    Ojcius, David M.; Hu, Wei-Lin; Ge, Yu-Mei; Lin, Xu’ai; Li, Lan-Juan; Pan, Jian-Ping; Yan, Jie

    2015-01-01

    Treg cells play a crucial role in immune tolerance, but mechanisms that induce Treg cells are poorly understood. We here have described eosinophils in lamina propria (LP) that displayed high aldehyde dehydrogenase (ALDH) activity, a rate-limiting step during all-trans retinoic acid (ATRA) synthesis, and expressed TGF-β1 mRNA and high levels of ATRA. Co-incubation assay confirmed that LP eosinophils induced the differentiation of naïve T cells into Treg cells. Differentiation promoted by LP eosinophils were inhibited by blocked either TGF-β1 or ATRA. Peripheral blood (PB) eosinophils did not produce ATRA and could not induce Treg differentiation. These data identifies LP eosinophils as effective inducers of Treg cell differentiation through a mechanism dependent on TGF-β1 and ATRA. PMID:26587591

  14. Lysophosphatidic acid induces YAP-promoted proliferation of human corneal endothelial cells via PI3K and ROCK pathways

    PubMed Central

    Hsueh, Yi-Jen; Chen, Hung-Chi; Wu, Sung-En; Wang, Tze-Kai; Chen, Jan-Kan; Ma, David Hui-Kang

    2015-01-01

    The first two authors contributed equally to this work.Silence of p120-catenin has shown promise in inducing proliferation in human corneal endothelial cells (HCECs), but there is concern regarding off-target effects in potential clinical applications. We aimed to develop ex vivo expansion of HCECs using natural compounds, and we hypothesized that lysophosphatidic acid (LPA) can unlock the mitotic block in contact-inhibited HCECs via enhancing nuclear translocation of yes-associated protein (YAP). Firstly, we verified that exogenous YAP could induce cell proliferation in contact-inhibited HCEC monolayers and postconfluent B4G12 cells. In B4G12 cells, enhanced cyclin D1 expression, reduced p27KIP1/p21CIP1 levels, and the G1/S transition were detected upon transfection with YAP. Secondly, we confirmed that LPA induced nuclear expression of YAP and promoted cell proliferation. Moreover, PI3K and ROCK, but not ERK or p38, were required for LPA-induced YAP nuclear translocation. Finally, cells treated with LPA or transfected with YAP remained hexagonal in shape, in addition to unchanged expression of ZO-1, Na/K-ATPase, and smooth muscle actin (SMA), suggestive of a preserved phenotype, without endothelial–mesenchymal transition. Collectively, our findings indicate an innovative strategy for ex vivo cultivation of HCECs for transplantation and cell therapy. PMID:26029725

  15. All-trans retinoic acid induces arginase-1 and inducible nitric oxide synthase-producing dendritic cells with T cell inhibitory function.

    PubMed

    Bhatt, Sumantha; Qin, Jie; Bennett, Carole; Qian, Shiguang; Fung, John J; Hamilton, Thomas A; Lu, Lina

    2014-06-01

    Hepatic stellate cells (HSC) are a major source of the immunoregulatory metabolite all-trans retinoic acid (ATRA), which may contribute to the generation of tolerogenic dendritic cells (DCs) in the liver. The present study seeks to clarify the mechanism(s) through which ATRA promotes the development of tolerogenic DCs. Although bone marrow-derived ATRA-treated DCs (RA-DCs) and conventional DCs had comparable surface phenotype, RA-DCs had diminished stimulatory capacity and could directly inhibit the expansion of DC/OVA-stimulated OT-II T cells. Arginase-1 (Arg-1) was found promote suppression because 1) ATRA was a potent inducer of Arg-1 protein and activity, 2) the Arg-1 inhibitor N(w)-hydroxy nor-l-arginine partially reversed suppression, and 3) the suppressive function of RA-DCs was partially compromised using OT-II T cells from GCN2(-/-) mice, which are insensitive to Arg-1. Inducible NO synthase (iNOS), however, was found to be a more significant contributor to RA-DC function because 1) ATRA potentiated the expression of IFN-γ-induced iNOS, 2) suppressive function in RA-DCs was blocked by the iNOS inhibitor N(G)-monomethyl-l-arginine, monoacetate salt, and 3) RA-DCs derived from iNOS(-/-) mice exhibited near complete loss of tolerogenic function, despite sustained Arg-1 activity. The expression of iNOS and the suppressive function of RA-DCs were dependent on both IFN-γ and ATRA. Furthermore, the in vivo behavior of RA-DCs proved to be consistent with their in vitro behavior. Thus, we conclude that ATRA enhances both Arg-1 and iNOS expression in IFN-γ-treated DCs, resulting in a tolerogenic phenotype. These findings elucidate mechanisms through which ATRA may contribute to liver immune tolerance. PMID:24790153

  16. The modulatory effect of ellagic acid and rosmarinic acid on ultraviolet-B-induced cytokine/chemokine gene expression in skin keratinocyte (HaCaT) cells.

    PubMed

    Lembo, Serena; Balato, Anna; Di Caprio, Roberta; Cirillo, Teresa; Giannini, Valentina; Gasparri, Franco; Monfrecola, Giuseppe

    2014-01-01

    Ultraviolet radiation (UV) induces an increase in multiple cutaneous inflammatory mediators. Ellagic acid (EA) and rosmarinic acid (RA) are natural anti-inflammatory and immunomodulatory compounds found in many plants, fruits, and nuts. We assessed the ability of EA and RA to modulate IL-1β, IL-6, IL-8, IL-10, MCP-1, and TNF-α gene expression in HaCaT cells after UVB irradiation. Cells were treated with UVB (100 mJ/cm(2)) and simultaneously with EA (5 μM in 0.1% DMSO) or RA (2.7 μM in 0.5% DMSO). Moreover, these substances were added to the UVB-irradiated cells 1 h or 6 h before harvesting, depending on the established UVB-induced cytokine expression peak. Cytokine gene expression was examined using quantitative real time polymerase chain reaction. RA produced a significant reduction in UVB-induced expression of IL-6, IL-8, MCP-1, and TNF-α when applied at the same time as irradiation. EA showed milder effects compared with RA, except for TNF-α. Both substances decreased IL-6 expression, also when applied 5 h after irradiation, and always produced a significant increase in UVB-induced IL-10 expression. Our findings suggest that EA and RA are able to prevent and/or limit the UVB-induced inflammatory cascade, through a reduction in proinflammatory mediators and the enhancement of IL-10, with its protective function. PMID:25162011

  17. Omega-3 fatty acids, EPA and DHA induce apoptosis and enhance drug sensitivity in multiple myeloma cells but not in normal peripheral mononuclear cells.

    PubMed

    Abdi, J; Garssen, J; Faber, J; Redegeld, F A

    2014-12-01

    The n-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to enhance the effect of chemotherapeutic drugs in clinical studies in cancer patients and to induce apoptotic tumor cell death in vitro. Until now, EPA and DHA have never been investigated in multiple myeloma (MM). Human myeloma cells (L363, OPM-1, OPM-2 and U266) and normal peripheral blood mononuclear cells were exposed to EPA and DHA, and effects on mitochondrial function and apoptosis, caspase-3 activation, gene expression and drug toxicity were measured. Exposure to EPA and DHA induced apoptosis and increased sensitivity to bortezomib in MM cells. Importantly, they did not affect viability of normal human peripheral mononuclear cells. Messenger RNA expression arrays showed that EPA and DHA modulated genes involved in multiple signaling pathways including nuclear factor (NF) κB, Notch, Hedgehog, oxidative stress and Wnt. EPA and DHA inhibited NFκB activity and induced apoptosis through mitochondrial perturbation and caspase-3 activation. Our study suggests that EPA and DHA induce selective cytotoxic effects in MM and increase sensitivity to bortezomib and calls for further exploration into a potential application of these n-3 polyunsaturated fatty acids in the therapy of MM. PMID:25277647

  18. Lysophosphatidic acid induces reactive oxygen species generation by activating protein kinase C in PC-3 human prostate cancer cells

    SciTech Connect

    Lin, Chu-Cheng; Lin, Chuan-En; Lin, Yueh-Chien; Ju, Tsai-Kai; Huang, Yuan-Li; Lee, Ming-Shyue; Chen, Jiun-Hong; Lee, Hsinyu

    2013-11-01

    Highlights: •LPA induces ROS generation through LPA{sub 1} and LPA{sub 3}. •LPA induces ROS generation by activating PLC. •PKCζ mediates LPA-induced ROS generation. -- Abstract: Prostate cancer is one of the most frequently diagnosed cancers in males, and PC-3 is a cell model popularly used for investigating the behavior of late stage prostate cancer. Lysophosphatidic acid (LPA) is a lysophospholipid that mediates multiple behaviors in cancer cells, such as proliferation, migration and adhesion. We have previously demonstrated that LPA enhances vascular endothelial growth factor (VEGF)-C expression in PC-3 cells by activating the generation of reactive oxygen species (ROS), which is known to be an important mediator in cancer progression. Using flow cytometry, we showed that LPA triggers ROS generation within 10 min and that the generated ROS can be suppressed by pretreatment with the NADPH oxidase (Nox) inhibitor diphenylene iodonium. In addition, transfection with LPA{sub 1} and LPA{sub 3} siRNA efficiently blocked LPA-induced ROS production, suggesting that both receptors are involved in this pathway. Using specific inhibitors and siRNA, phospholipase C (PLC) and protein kinase C (PKC) were also suggested to participate in LPA-induced ROS generation. Overall, we demonstrated that LPA induces ROS generation in PC-3 prostate cancer cells and this is mediated through the PLC/PKC/Nox pathway.

  19. Carnosic acid inhibits STAT3 signaling and induces apoptosis through generation of ROS in human colon cancer HCT116 cells.

    PubMed

    Kim, Do-Hee; Park, Ki-Woong; Chae, In Gyeong; Kundu, Juthika; Kim, Eun-Hee; Kundu, Joydeb Kumar; Chun, Kyung-Soo

    2016-06-01

    Carnosic acid (CA), the main antioxidant compound of Rosmarinus officinalis L., has been reported to possess anticancer activity. However, the molecular mechanisms underlying the anticancer effects of CA remain poorly understood. Our study revealed that CA treatment significantly reduced the viability of human colon cancer HCT116, SW480, and HT-29 cells. Treatment with CA induced apoptosis, which was associated with the induction of p53 and Bax, inhibition of Mdm2, Bcl-2, and Bcl-xl expression, activation of caspase-9, and -3, and the cleavage of PARP in HCT116 cells. CA inhibited the constitutive phosphorylation, the DNA binding and the reporter gene activity of STAT3 in HCT116 cells by blocking the phosphorylation of upstream JAK2 and Src kinases. Moreover, CA attenuated the expression of STAT3 target gene products, such as survivin, cyclin D1, D2, and D3. In STAT3-overexpressed HCT116 cells, CA inhibited cell viability and the expression of cyclin D1 and survivin. Furthermore, CA treatment induced the generation of ROS in these colon cancer cells. Pretreatment of cells with ROS scavenger N-acetyl cysteine abrogated the inhibitory effect of CA on the JAK2-STAT3/Src-STAT3 signaling and rescued cells from CA-induced apoptosis by blocking the induction of p53 and the cleavage of caspase-3 and PARP in HCT116 cells. However, L-buthionine-sulfoximine, a pharmacological inhibitor of GSH synthesis, increased CA-induced ROS production, thereby potentiating apoptotic effect of CA. In conclusion, our study provides the first report that CA induced apoptosis in HCT116 cells via generation of ROS, induction of p53, activation of caspases, and inhibition of STAT3 signaling pathway. © 2015 Wiley Periodicals, Inc. PMID:26152521

  20. Retinoic acid induced the differentiation of neural stem cells from embryonic spinal cord into functional neurons in vitro

    PubMed Central

    Tan, Bo-Tao; Wang, Li; Li, Sen; Long, Zai-Yun; Wu, Ya-Min; Liu, Yuan

    2015-01-01

    Retinoic acid is an important molecular taking part in the development and homeostasis of nervous system. Neural stem cells (NSCs) are pluripotent cells that can differentiate into three main neural cells including neuron, astrocyte and oligodendrocyte. However, whether retinoic acid can induce NSCs derived from embryonic spinal cord differentiating into functional neurons and its efficiency are not clear. In this experiment, NSCs were isolated from embryonic 14 d spinal cord of rats. The growth and neuronal differentiation of NSCs induced by 500 nM RA was examined in vitro. It was indicated that compared with the control group, there were more differentiated cells with longer cytodendrites in the medium treated with RA at different time. And more, there were more neuronal marker positive cells in 500 nM RA group than the control group seven days after differentiation. At the same time, the expression of β-tublin III protein in RA group was higher than those in control group, which was contrary to the expression of astrocyte marker GFAP protein at seven days after differentiation. However the differentiated neurons, whether treated with RA or not both exhibited biological electrical reactivity after stimulated by glutamine. Therefore, these findings indicated that RA could promote growth of cellular dendrites and neuronal differentiation of NSCs, which also induce functional maturation of differentiated neurons finally. PMID:26339381

  1. Phosphorylation of CREB, a cyclic AMP responsive element binding protein, contributes partially to lysophosphatidic acid-induced fibroblast cell proliferation

    SciTech Connect

    Kwon, Yong-Jun; Sun, Yuanjie; Kim, Nam-Ho; Huh, Sung-Oh

    2009-03-13

    Lysophospholipids regulate a wide array of biological processes including cell survival and proliferation. In our previous studies, we found that in addition to SRE, CRE is required for maximal c-fos promoter activation triggered by lysophosphatidic acid (LPA). c-fos is an early indicator of various cells into the cell cycle after mitogenic stimulation. However, role of CREB activation in LPA-stimulated proliferation has not been elucidated yet. Here, we investigate how LPA induces proliferation in Rat-2 fibroblast cell via CREB activation. We found that total cell number and BrdU-positive cells were increased by LPA. Moreover, levels of c-fos mRNA and cyclin D1 protein were increased via LPA-induced CREB phosphorylation. Furthermore, LPA-induced Rat-2 cell proliferation was decreased markedly by ERK inhibitor (U0126) and partially by MSK inhibitor (H89). Taken together, these results suggest that CREB activation could partially up-regulate accumulation of cyclin D1 protein level and proliferation of LPA-stimulated Rat-2 fibroblast cells.

  2. Allicin alleviates inflammation of trinitrobenzenesulfonic acid-induced rats and suppresses P38 and JNK pathways in Caco-2 cells.

    PubMed

    Li, Chen; Lun, Weijian; Zhao, Xinmei; Lei, Shan; Guo, Yandong; Ma, Jiayi; Zhi, Fachao

    2015-01-01

    Background. Allicin has anti-inflammatory, antioxidative and proapoptotic properties. Aims. To evaluate the effects and investigate the mechanism of allicin on trinitrobenzenesulfonic acid-induced colitis, specifically with mesalazine or sulfasalazine. Methods. 80 rats were divided equally into 8 groups: control; trinitrobenzenesulfonic acid; allicin prevention; allicin; mesalazine; sulfasalazine; allicin + sulfasalazine, and mesalazine + allicin. Systemic and colonic inflammation parameters were analysed. In addition, protein and culture medium of Caco-2 cells treated with various concentrations of IL-1β or allicin were collected for investigation of IL-8, NF-κB p65 P38, ERK, and JNK. One-way ANOVA and Kruskal-Wallis H test were used for parametric and nonparametric tests, respectively. Results. Allicin reduced the body weight loss of trinitrobenzenesulfonic acid-induced rats, histological score, serum TNF-α and IL-1β levels, and colon IL-1β mRNA level and induced serum IL-4 level, particularly in combination with mesalazine. In addition, 1 ng/mL IL-1β stimulated the P38, ERK, and JNK pathways, whereas pretreatment with allicin depressed this phenomenon, except for the ERK pathway. Conclusions. The inflammation induced by trinitrobenzenesulfonic acid is mitigated significantly by allicin treatment, particularly combined with mesalazine. Allicin inhibits the P38 and JNK pathways and the expression of NF-κB which explained the potential anti-inflammatory mechanisms of allicin. PMID:25729217

  3. The Expression of Bone Morphogenetic Protein 2 and Matrix Metalloproteinase 2 through Retinoic Acid Receptor Beta Induced by All-Trans Retinoic Acid in Cultured ARPE-19 Cells

    PubMed Central

    Gao, Zhenya; Huo, Lijun; Cui, Dongmei; Yang, Xiao; Zeng, Junwen

    2016-01-01

    Purpose All-trans retinoic acid (ATRA) plays an important role in ocular development. Previous studies found that retinoic acid could influence the metabolism of scleral remodeling by promoting retinal pigment epithelium (RPE) cells to secrete secondary signaling factors. The purpose of this study was to investigate whether retinoic acid affected secretion of bone morphogenetic protein 2 (BMP-2) and matrix metalloproteinase 2 (MMP-2) and to explore the signaling pathway of retinoic acid in cultured acute retinal pigment epithelial 19 (ARPE-19) cells. Methods The effects of ATRA (concentrations from 10−9 to 10−5 mol/l) on the expression of retinoic acid receptors (RARs) in ARPE-19 cells were examined at the mRNA and protein levels using reverse transcription-polymerase chain reaction (RT-PCR) and western blot assay, respectively. The effects of treating ARPE-19 cells with ATRA concentrations ranging from 10−9 to 10−5 mol/l for 24 h and 48 h or with 10-6mol/l ATRA at different times ranging from 6h to 72h were assessed using real-time quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). The contribution of RARβ-induced activation of ARPE-19 cells was confirmed using LE135, an antagonist of RARβ. Results RARβ mRNA levels significantly increased in the ARPE-19 cells treated with ATRA for 24h and 48h. These increases in RARβ mRNA levels were dose dependent (at concentrations of 10−9 to 10−5 mol/l) with a maximum effect observed at 10−6 mol/l. There were no significant changes in the mRNA levels of RARα and RARγ. Western blot assay revealed that RARβ protein levels were increased significantly in a time-dependent manner in ARPE-19 cells treated with 10−6 mol/l ATRA from 12 h to 72 h, with a marked increase observed at 24 h and 48 h. The upregulation of RARβ and the ATRA-induced secretion in ARPE-19 cells could be inhibited by the RARβ antagonist LE135. Conclusion ATRA induced upregulation of RARβ in ARPE-19 cells and stimulated

  4. fat-1 transgene expression prevents cell culture-induced loss of membrane n-3 fatty acids in activated CD4+ T-cells.

    PubMed

    Fan, Yang-Yi; Kim, Wooki; Callaway, Evelyn; Smith, Roger; Jia, Qian; Zhou, Lan; McMurray, David N; Chapkin, Robert S

    2008-12-01

    In order to evaluate the effects of fatty acids on immune cell membrane structure and function, it is often necessary to maintain cells in culture. However, cell culture conditions typically reverse alterations in polyunsaturated fatty acid (PUFA) composition achieved by dietary lipid manipulation. Therefore, we hypothesized that T-cells from transgenic mice expressing the Caenorhabditis elegans n-3 desaturase (fat-1) gene would be resistant to the culture-induced loss of n-3 PUFA and, therefore, obviate the need to incorporate fatty acids or homologous serum into the medium. CD4+ T-cells were isolated from (i) control wild type (WT) mice fed a safflower oil-n-6 PUFA enriched diet (SAF) devoid of n-3 PUFA, (ii) fat-1 transgenic mice (enriched with endogenous n-3 PUFA) fed a SAF diet, or (iii) WT mice fed a fish oil (FO) based diet enriched in n-3 PUFA. T-cell phospholipids isolated from WT mice fed FO diet (enriched in n-3 PUFA) and fat-1 transgenic mice fed a SAF diet (enriched in n-6 PUFA) were both enriched in n-3 PUFA. As expected, the mol% levels of both n-3 and n-6 PUFA were decreased in cultures of CD4+ T-cells from FO-fed WT mice after 3d in culture. In contrast, the expression of n-3 desaturase prevented the culture-induced decrease of n-3 PUFA in CD4+ T-cells from the transgenic mice. Carboxyfluorescein succinidyl ester (CFSE) -labeled CD4+ T-cells from fat-1/SAF vs. WT/SAF mice stimulated with anti-CD3 and anti-CD28 for 3d, exhibited a reduced (P<0.05) number of cell divisions. We conclude that fat-1-containing CD4+ T-cells express a physiologically relevant, n-3 PUFA enriched, membrane fatty acid composition which is resistant to conventional cell culture-induced depletion. PMID:18977126

  5. Pathways through which a regimen of melatonin and retinoic acid induces apoptosis in MCF-7 human breast cancer cells.

    PubMed

    Eck-Enriquez, K; Kiefer, T L; Spriggs, L L; Hill, S M

    2000-06-01

    It has been established that melatonin (Mlt) and retinoic acid, individually, inhibit the proliferation of the estrogen receptor-alpha (ER alpha)-positive MCF-7 breast cancer cell line. Our laboratory has previously demonstrated that Mlt and all-trans-retinoic acid (atRA) not only inhibit the proliferation, but also induce apoptosis of MCF-7 cells when used in a sequential regimen of Mlt followed 24 h later by atRA. Using this same MCF-7 breast cancer cell line, we investigated the potential pathways through which apoptosis is being induced. We found that treatment of MCF-7 cells with Mlt for 24 h before the addition of atRA decreased the protein levels of the death suppressor, Bcl-2, and increased, although with different time courses, the levels of the death promoters, Bax and Bak; however, there was no change in the levels of the tumor suppressor gene, p53. MCF-7 cells treated sequentially with Mlt and atRA also demonstrated an enhanced sensitivity to the apoptotic effects of atRA, which did not appear to be due to increased expression of the retinoic acid receptors, RAR alpha or RXR alpha, but rather to enhanced transcriptional activity of the RAR alpha. These data suggest that the sequential treatment regimen of Mlt and atRA may induce apoptosis by modulation of members of the Bcl-2 family of proteins. Thus, this combinatorial regimen, which reduces the concentration of atRA needed for clinical efficacy while enhancing its anti-tumorigenic activity, could be of great therapeutic benefit, and may, in fact, specifically induce the regression of established breast tumors due to its apoptosis-promoting effects. PMID:10965999

  6. Progesterone receptor activation is required for folic acid-induced anti-proliferation in colorectal cancer cell lines.

    PubMed

    Kuo, Chun-Ting; Lee, Wen-Sen

    2016-08-10

    Previously, we demonstrated that folic acid (FA) could inhibit proliferation of colorectal cancer cell lines through activating the folate receptor (FR)α/cSrc/ERK1/2/NFκB/p53 pathway and anti-COLO-205 tumor growth in vivo. Since we recently also demonstrated that female sex hormones could affect the FA's action in regulating endothelial cell proliferation and migration, the aim of this study was to investigate the effect of progesterone (P4) on the FA-induced anti-proliferation in colorectal cancer cells. Treatment with FA significantly reduced the proliferation of the P4 receptor (PR)-positive colon cancer cell lines, COLO-205, HT-29 and LoVo, but did not significantly affect the proliferation of the PR-negative colon cancer cell lines, HCT116 and DLD-1. Pre-treatment with Org 31710, a PR specific antagonist, abolished the FA-induced proliferation inhibition and activation in the signaling pathway involved in regulating proliferation inhibition in these PR positive colorectal cancer cell lines. The involvement of PR in the FA-induced activation of cSrc and up-regulations in cell cycle inhibitory proteins (p21, p27 and p53) was confirmed by knock-down of PR expression using the siRNA technique. Importantly, we show direct protein interaction between FR and PR in COLO-205. Moreover, treatment with FA induced PR activation in COLO-205. Taken together, these data suggest that FA induced proliferation inhibition in colon cancer cells through activation of PR. This finding might explain some of the controversies of FA's effects on cancer growth and provide valuable reference for clinical applications of FA in treating colorectal cancer. PMID:27233474

  7. Carnosic acid induces apoptosis through inactivation of Src/STAT3 signaling pathway in human renal carcinoma Caki cells.

    PubMed

    Park, Ji Eun; Park, Byoungduck; Chae, In Gyeong; Kim, Do-Hee; Kundu, Juthika; Kundu, Joydeb Kumar; Chun, Kyung-Soo

    2016-05-01

    Carnosic acid (CA), the major bioactive compound of Rosmarinus officinalis L., has been reported to possess anti-inflammatory and anticancer activities. However, the molecular mechanisms underlying the anticancer effects of CA remain poorly understood. In the present study, we investigated that CA significantly reduced the viability of human renal carcinoma Caki cells. CA-induced apoptosis was connected with the cleavage of caspase-9, -7 and -3, and that of PARP. Moreover, CA increased the expression of pro-apoptotic protein Bax and diminished the expression of anti-apoptotic protein Bcl-2 and Bcl-xL, thereby releasing cytochrome c into the cytosol. Treatment with CA in Caki cells also induced the expression of p53 and its target gene product, p27, through down-regulation of Murine double minute-2 (Mdm2). Furthermore, CA generated reactive oxygen species (ROS), and pretreatment with ROS scavenger N-acetyl cysteine (NAC) abrogated CA-induced cleavage of PARP and expression of p53. One of the key oncogenic signals is mediated through signal transducer and activator of transcription-3 (STAT3), which promotes abnormal cell proliferation. Incubation of cells with CA markedly diminished the phosphorylation of STAT3 and its upstream, Src, and reduced the expression of STAT3 responsive gene products, such as D-series of cyclins and survivin. Taken together, the present study revealed that CA induced apoptosis in Caki cells by induction of p53 and suppression of STAT3 signaling. PMID:26936454

  8. Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

    SciTech Connect

    Becker, Jan C. . E-mail: beckeja@uni-muenster.de; Grosser, Nina; Waltke, Christian; Schulz, Stephanie; Erdmann, Kati; Domschke, Wolfram; Schroeder, Henning; Pohle, Thorsten

    2006-07-07

    Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection.

  9. Hexadecanoic acid from Buzhong Yiqi decoction induced proliferation of bone marrow mesenchymal stem cells.

    PubMed

    Chen, Dong-Feng; Li, Xican; Xu, Zhiwei; Liu, Xiaobing; Du, Shao-Hui; Li, Hui; Zhou, Jian-Hong; Zeng, He-Ping; Hua, Zi-Chun

    2010-08-01

    Buzhong Yiqi decoction (BYD) is a well-known ancient tonic prescription in traditional Chinese medicine (TCM). The purpose of this study is to identify active components of BYD involved in promoting proliferation of mesenchymal stem cells (MSCs) and to investigate its mechanism. BYD was extracted with petroleum ether, ethanol, and water. Evidence provided by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, bromodeoxyuridine, proliferation cell nuclear antigen immunoreactivity, cell cycle analysis, and gas chromatography-mass spectrometry indicated that hexadecanoic acid (HA) in BYD extracted with petroleum ether is the active compound responsible for increasing proliferation of MSCs. Western blot analysis show that HA significantly increase retinoic acid receptor (RAR) levels of MSCs, but not estrogen receptor, thyroid hormone receptor, vitamin D receptor, glucocorticoid receptor, and peroxisome proliferator-activated receptor. Reverse transcription-polymerase chain reaction revealed that HA significantly increased RAR mRNA levels. Furthermore, the mechanism of HA action depends on RAR pathway and up-regulates expression of mRNA for insulin-like growth factor-I, the target gene of RAR. Our findings have now allowed for a refinement in our understanding of TCM with respect to pharmacological regulation of stem cells and may be useful to stem cell biology and therapy. PMID:20482257

  10. Docosahexaenoic acid counteracts attenuation of CD95-induced cell death by inorganic mercury

    SciTech Connect

    Gill, Randall; Lanni, Lydia; Jen, K.-L. Catherine; McCabe, Michael J.; Rosenspire, Allen

    2015-01-01

    In the United States the principal environmental exposure to mercury is through dietary consumption of sea food. Although the mechanism by which low levels of mercury affect the nervous system is not well established, epidemiological studies suggest that low level exposure of pregnant women to dietary mercury can adversely impact cognitive development in their children, but that Docosahexaenoic acid (DHA), the most prominent n-polyunsaturated fatty acid (n-PUFA) present in fish may counteract negative effects of mercury on the nervous system. Aside from effects on the nervous system, epidemiological and animal studies have also suggested that low level mercury exposure may be a risk factor for autoimmune disease. However unlike the nervous system where a mechanism linking mercury to impaired cognitive development remains elusive, we have previously suggested a potential mechanism linking low level mercury exposures to immune system dysfunction and autoimmunity. In the immune system it is well established that disruption of CD95 mediated apoptosis leads to autoimmune disease. We have previously shown in vitro as well as in vivo that in lymphocytes burdened with low levels of mercury, CD95 mediated cell death is impaired. In this report we now show that DHA counteracts the negative effect of mercury on CD95 signaling in T lymphocytes. T cells which have been pre-exposed to DHA are able to cleave pro-caspase 3 and efficiently signal programmed cell death through the CD95 signaling pathway, whether or not they are burdened with low levels of mercury. Thus DHA may lower the risk of autoimmune disease after low level mercury exposures. - Highlights: • Inorganic mercury (Hg{sup 2+}) interferes with CD95 mediated cell death in Jurkat T cells • DHA restores the ability of CD95 to signal cell death in Hg{sup 2+} intoxicated T cells • The restoration of CD95 mediated cell death by DHA is correlated with increased activation of Caspase 3.

  11. Eicosapentaenoic acid inhibits TNF-{alpha}-induced matrix metalloproteinase-9 expression in human keratinocytes, HaCaT cells

    SciTech Connect

    Kim, Hyeon Ho; Lee, Youngae; Eun, Hee Chul Chung, Jin Ho

    2008-04-04

    Eicosapentaenoic acid (EPA) is an omega-3 ({omega}-3) polyunsaturated fatty acid (PUFA), which has anti-inflammatory and anti-cancer properties. Some reports have demonstrated that EPA inhibits NF-{kappa}B activation induced by tumor necrosis factor (TNF)-{alpha} or lipopolysaccharide (LPS) in various cells. However, its detailed mode of action is unclear. In this report, we investigated whether EPA inhibits the expression of TNF-{alpha}-induced matrix metalloproteinases (MMP)-9 in human immortalized keratinocytes (HaCaT). TNF-{alpha} induced MMP-9 expression by NF-{kappa}B-dependent pathway. Pretreatment of EPA inhibited TNF-{alpha}-induced MMP-9 expression and p65 phosphorylation. However, EPA could not affect I{kappa}B-{alpha} phosphorylation, nuclear translocation of p65, and DNA binding activity of NF-{kappa}B. EPA inhibited TNF-{alpha}-induced p65 phosphorylation through p38 and Akt inhibition and this inhibition was IKK{alpha}-dependent event. Taken together, we demonstrate that EPA inhibits TNF-{alpha}-induced MMP-9 expression through inhibition of p38 and Akt activation.

  12. Retinoic acid induces nuclear FAK translocation and reduces breast cancer cell adhesion through Moesin, FAK, and Paxillin.

    PubMed

    Sanchez, Angel Matías; Shortrede, Jorge Eduardo; Vargas-Roig, Laura María; Flamini, Marina Inés

    2016-07-15

    Breast cancer is the most common malignancy in women, with metastases being the cause of death in 98%. In previous works we have demonstrated that retinoic acid (RA), the main retinoic acid receptor (RAR) ligand, is involved in the metastatic process by inhibiting migration through a reduced expression of the specific migration-related proteins Moesin, c-Src, and FAK. At present, our hypothesis is that RA also acts for short periods in a non-genomic action to cooperate with motility reduction and morphology of breast cancer cells. Here we identify that the administration of 10(-6) M RA (10-20 min) induces the activation of the migration-related proteins Moesin, FAK, and Paxillin in T-47D breast cancer cells. The phosphorylation exerted by the selective agonists for RARα and RARβ, on Moesin, FAK, and Paxillin was comparable to the activation exerted by RA. The RARγ agonist only led to a weak activation, suggesting the involvement of RARα and RARβ in this pathway. We then treated the cells with different inhibitors that are involved in cell signaling to regulate the mechanisms of cell motility. RA failed to activate Moesin, FAK, and Paxillin in cells treated with Src inhibitor (PP2) and PI3K inhibitor (WM), suggesting the participation of Src-PI3K in this pathway. Treatment with 10(-6) M RA for 20 min significantly decreased cell adhesion. However, when cells were treated with 10(-6) M RA and FAK inhibitor, the RA did not significantly inhibit adhesion, suggesting a role of FAK in the adhesion inhibited by RA. By immunofluorescence and immunoblotting analysis we demonstrated that RA induced nuclear FAK translocation leading to a reduced cellular adhesion. These findings provide new information on the actions of RA for short periods. RA participates in cell adhesion and subsequent migration, modulating the relocation and activation of proteins involved in cell migration. PMID:27130522

  13. Swelling-activated and arachidonic acid-induced currents are TREK-1 in rat bladder smooth muscle cells.

    PubMed

    Fukasaku, Mitsuko; Kimura, Junko; Yamaguchi, Osamu

    2016-06-01

    Using the perforated patch voltage clamp, we investigated swelling-activated ionic channels (SACs) in rat urinary bladder smooth muscle cells. Hypo-osmotic (60%) bath solution increased a membrane current which was inhibited by the SAC inhibitor, gadolinium. The reversal potential of the hypotonicity-induced current shifted in the positive direction by increasing external K(+) concentration. The hypotonicity-induced current was inhibited by extracellular acidic pH, phorbol ester and forskolin. These pharmacological properties are identical to those of arachidonic acid-induced current present in these cells, suggesting the presence of TREK-1, a four-transmembrane two pore domain K(+) channel. Using RT-PCR we screened rat bladder smooth muscles and cerebellum for expression of TREK-1, TREK-2 and TRAAK mRNAs. Only TREK-1 mRNA was expressed in the bladder, while all three were expressed in the cerebellum. We conclude that a mechanosensitive K(+) channel is present in rat bladder myocytes, which is activated by arachidonic acid and most likely is TREK-1. This K(+) channel may have an important role in the regulation of bladder smooth muscle tone during urine storage. PMID:26911303

  14. Signalling Through Retinoic Acid Receptors is Required for Reprogramming of Both Mouse Embryonic Fibroblast Cells and Epiblast Stem Cells to Induced Pluripotent Stem Cells

    PubMed Central

    Yang, Jian; Wang, Wei; Ooi, Jolene; Campos, Lia S.

    2015-01-01

    Abstract We previously demonstrated that coexpressing retinoic acid (RA) receptor gamma and liver receptor homolog‐1 (LRH1 or NR5A2) with OCT4, MYC, KLF4, and SOX2 (4F) rapidly reprograms mouse embryonic fibroblast cells (MEFs) into induced pluripotent stem cells (iPSCs). Here, we further explore the role of RA in reprogramming and report that the six factors (6F) efficiently and directly reprogram MEFs into integration‐free iPSCs in defined medium (N2B27) in the absence of feeder cells. Through genetic and chemical approaches, we find that RA signalling is essential, in a highly dose‐sensitive manner, for MEF reprogramming. The removal of exogenous RA from N2B27, the inhibition of endogenous RA synthesis or the expression of a dominant‐negative form of RARA severely impedes reprogramming. By contrast, supplementing N2B27 with various retinoids substantially boosts reprogramming. In addition, when coexpressed with LRH1, RA receptors (RARs) can promote reprogramming in the absence of both exogenous and endogenously synthesized RA. Remarkably, the reprogramming of epiblast stem cells into embryonic stem cell‐like cells also requires low levels of RA, which can modulate Wnt signalling through physical interactions of RARs with β‐catenin. These results highlight the important functions of RA signalling in reprogramming somatic cells and primed stem cells to naïve pluripotency. Stem Cells 2015;33:1390–1404 PMID:25546009

  15. Ascorbic acid delivered by mesoporous silica nanoparticles induces the differentiation of human embryonic stem cells into cardiomyocytes.

    PubMed

    Ren, Mingming; Han, Zhen; Li, Jinglai; Feng, Gang; Ouyang, Shuyuan

    2015-11-01

    Embryonic stem (ES) cells offer the potential to generate all cell types in the body, which provide a promising approach to repair tissue damage or dysfunction. In the past decade, great efforts have been made to induce the differentiation of ES cells into numerous types of cells, such as adipocytes, neurocytes and cardiomyocytes. However, the low differentiated efficiency and successful rate limit the development of induction of the differentiation of stem cells for tissue engineering. Here, we utilize ascorbic acid (AA)-loaded fluorescent TRITC-mesoporous silica nanoparticles (TMSN-AA) as a potential tool to induce the differentiation of human ES cells into cardiomyocytes. The treatment of human ES cells by TMSN-AA nanoplex arrests cell cycle at G1 phase and decreases the expression of stemness genes octamer-binding transcription factor 4 (OCT4) and sex determining region Y-box 2 (SOX2), which exhibits more significant induction efficiency of stem cell differentiation than the treatment by AA alone. Furthermore, we have tested the myocardial marker genes cardiac Troponin I (cTnI) and fetal liver kinase 1 (FLK-1), and found these genes are up-regulated by TMSN-AA nanoplex. Importantly, this work demonstrates the more efficient induction efficiency of human ES cells differentiation by the nanoparticle-drug formulation. Our studies reveal a novel approach based on MSNs as nanocarriers to induce the differentiation of human ES cells into cardiomyocytes efficiently and feasibly, and offer the potential perspectives for tissue engineering, eventually in clinical applications. PMID:26249600

  16. Retinoic acid inhibits the proliferative response induced by CD40 activation and interleukin-4 in mantle cell lymphoma.

    PubMed

    Guidoboni, Massimo; Zancai, Paola; Cariati, Roberta; Rizzo, Silvana; Dal Col, Jessica; Pavan, Alessandro; Gloghini, Annunziata; Spina, Michele; Cuneo, Antonio; Pomponi, Fabrizio; Bononi, Antonio; Doglioni, Claudio; Maestro, Roberta; Carbone, Antonino; Boiocchi, Mauro; Dolcetti, Riccardo

    2005-01-15

    Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin's lymphoma with poor response to therapy and unfavorable prognosis. Here, we show that retinoic acid (RA) isomers significantly inhibit the proliferation of both primary MCL cultures (n = 7) and established cell lines (Granta 519 and SP-53) as shown by [(3)H]thymidine uptake and carboxyfluorescein diacetate succinimidyl ester labeling coupled with cyclin D1 staining. RA induces cell accumulation in G(0)-G(1) together with a marked up-regulation of p27(Kip1) by inhibiting ubiquitination and proteasome-dependent degradation of the protein. The p21(Cip1) inhibitor was also up-regulated by RA in Granta 519 cells, whereas the expression of cyclin D1 is unaffected. Most of RA-induced p27(Kip1) was bound to cyclin D1/cyclin-dependent kinase 4 complexes, probably contributing to the decreased cyclin-dependent kinase 4 kinase activity and pRb hypophosphorylation observed in RA-treated cells. Experiments with receptor-selective ligands indicate that RA receptor alpha cooperates with retinoid X receptors in mediating RA-dependent MCL cell growth inhibition. Notably, RA isomers, and particularly 9-cis-RA, also inhibited the growth-promoting effect induced in primary MCL cells by CD40 activation alone or in combination with interleukin-4. Immunohistochemical analysis showed that significant numbers of CD40L-expressing lymphoid cells are present in lymph node biopsies of MCL patients. These results therefore further strengthen the possibility that triggering of CD40 by infiltrating CD40L+ cells may continuously promote the growth of MCL cells in vivo. On these grounds, our findings that RA inhibits basal MCL proliferation as well as MCL growth-promoting effects exerted by microenvironmental factors make these compounds highly attractive in terms of potential clinical efficacy in this setting. PMID:15695403

  17. The Lactic Acid Bacterium Pediococcus acidilactici Suppresses Autoimmune Encephalomyelitis by Inducing IL-10-Producing Regulatory T Cells

    PubMed Central

    Takata, Kazushiro; Kinoshita, Makoto; Okuno, Tatsusada; Moriya, Masayuki; Kohda, Tohru; Honorat, Josephe A.; Sugimoto, Tomoyuki; Kumanogoh, Atsushi; Kayama, Hisako; Takeda, Kiyoshi; Sakoda, Saburo; Nakatsuji, Yuji

    2011-01-01

    Background Certain intestinal microflora are thought to regulate the systemic immune response. Lactic acid bacteria are one of the most studied bacteria in terms of their beneficial effects on health and autoimmune diseases; one of which is Multiple sclerosis (MS) which affects the central nervous system. We investigated whether the lactic acid bacterium Pediococcus acidilactici, which comprises human commensal bacteria, has beneficial effects on experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Methodology/Principal Findings P. acidilactici R037 was orally administered to EAE mice to investigate the effects of R037. R037 treatment suppressed clinical EAE severity as prophylaxis and therapy. The antigen-specific production of inflammatory cytokines was inhibited in R037-treated mice. A significant increase in the number of CD4+ Interleukin (IL)-10-producing cells was observed in the mesenteric lymph nodes (MLNs) and spleens isolated from R037-treated naive mice, while no increase was observed in the number of these cells in the lamina propria. Because only a slight increase in the CD4+Foxp3+ cells was observed in MLNs, R037 may primarily induce Foxp3− IL10-producing T regulatory type 1 (Tr1) cells in MLNs, which contribute to the beneficial effect of R037 on EAE. Conclusions/Significance An orally administered single strain of P. acidilactici R037 ameliorates EAE by inducing IL10-producing Tr1 cells. Our findings indicate the therapeutic potential of the oral administration of R037 for treating multiple sclerosis. PMID:22110705

  18. Fatty acid biosynthesis from glutamate and glutamine is specifically induced in neuronal cells under hypoxia

    PubMed Central

    Brose, Stephen A.; Marquardt, Amanda L.; Golovko, Mikhail Y.

    2014-01-01

    Hypoxia is involved in many neuronal and non-neuronal diseases, and defining the mechanisms for tissue adaptation to hypoxia is critical for the understanding and treatment of these diseases. One mechanism for tissue adaptation to hypoxia is increased glutamine and/or glutamate (Gln/Glu) utilization. To address this mechanism, we determined total Gln/Glu incorporation into lipids and fatty acids in both primary neurons and a neuronal cell line under normoxic and hypoxic conditions and compared this to non-neuronal primary cells and non-neuronal cell lines. Incorporation of Gln/Glu into total lipids was dramatically and specifically increased under hypoxia in neuronal cells including both primary (2.0- and 3.0- fold for Gln and Glu, respectively) and immortalized cultures (3.5- and 8.0- fold for Gln and Glu, respectively), and 90% to 97% of this increase was accounted for by incorporation into fatty acids (FA) depending upon substrate and cell type. All other non-neuronal cells tested demonstrated decreased or unchanged FA synthesis from Gln/Glu under hypoxia. Consistent with these data, total FA mass was also increased in neuronal cells under hypoxia that was mainly accounted for by the increase in saturated and monounsaturated FA with carbon length from 14 to 24. Incorporation of FA synthesized from Gln/Glu was increased in all major lipid classes including cholesteryl esters, TAGs, DAGs, free FA, and phospholipids, with the highest rate of incorporation into TAGs. These results indicate that increased FA biosynthesis from Gln/Glu followed by esterification may be a neuronal specific pathway for adaptation to hypoxia. PMID:24266789

  19. PI3K/Akt pathway regulates retinoic acid-induced Hox gene expression in F9 cells.

    PubMed

    Lee, Youra; Lee, Ji-Yeon; Kim, Myoung Hee

    2014-09-01

    Retinoic acid (RA), the most potent natural form of vitamin A, is a key morphogen in vertebrate development and a potent regulator of both adult and embryonic cell differentiation. Specifically, RA regulates clustered Hox gene expression during embryogenesis and is required to establish the anteroposterior body plan. The PI3K/Akt pathway was also reported to play an essential role in the process of RA-induced cell differentiation. Therefore, we tested whether the PI3K/Akt pathway is involved in RA-induced Hox gene expression in a F9 murine embryonic teratocarcinoma cells. To examine the effect of PI3K/Akt signaling on RA-induced initiation of collinear expression of Hox genes, F9 cells were treated with RA in the presence or absence of PI3K inhibitor LY294002, and time-course gene expression profiles for all 39 Hox genes located in four different clusters-Hoxa, Hoxb, Hoxc, and Hoxd-were analyzed. Collinear expression of Hoxa and -b cluster genes was initiated earlier than that of the -c and -d clusters upon RA treatment. When LY294002 was applied along with RA, collinear expression induced by RA was delayed, suggesting that the PI3K/Akt signaling pathway somehow regulates RA-induced collinear expression of Hox genes in F9 cells. The initiation of Hox collinear expression by RA and the delayed expression following LY294002 in F9 cells would provide a good model system to decipher the yet to be answered de novo collinear expression of Hox genes during gastrulation, which make the gastrulating cells to remember their positional address along the AP body axis in the developing embryo. PMID:25212816

  20. CD4+ T cell responses in Balb/c mice with food allergy induced by trinitrobenzene sulfonic acid and ovalbumin.

    PubMed

    Sun, Chen-Yi; Bai, Jie; Hu, Tian-Yong; Cheng, Bao-Hui; Ma, Li; Fan, Xiao-Qin; Yang, Ping-Chang; Zheng, Peng-Yuan; Liu, Zhi-Qiang

    2016-06-01

    The rapid increase in atopic diseases is potentially linked to increased hapten exposure, however, the role of haptens in the pathogenesis of food allergy remains unknown. Further studies are required to elucidate the cluster of differentiation 4 positive (CD4+) T cell response to food allergy induced by haptens. Dendritic cells were primed by trinitrobenzene sulfonic acid (TNBS) as a hapten or ovalbumin (OVA) as a model antigen, in a cell culture model. BALB/c mice were sensitized using TNBS and/or OVA. Intestinal Th1/Th2 cell and ovalbumin specific CD4+ T cells proliferation, intestinal cytokines (interleukin‑4 and interferon‑γ) in CD4+ T cells were evaluated. TNBS increased the expression of T cell immunoglobulin and mucin domain‑4 and tumor necrosis factor ligand superfamily member 4 in dendritic cells. Skewed Th2 cell polarization, extensive expression of interleukin‑4, reduced expression of interferon‑γ and forkhead box protein P3 were elicited following concomitant exposure to TNBS and OVA, with reduced regulatory T cells in the mouse intestinal mucosa, whereas a Th1 response was detected when challenged by TNBS or OVA alone. This data suggests that TNBS, as a hapten, combined with food antigens may lead to a Th2 cell response in the intestinal mucosa. PMID:27109448

  1. Human B-cell lymphoma cell lines are highly sensitive to apoptosis induced by all-trans retinoic acid and interferon-gamma.

    PubMed

    Niitsu, Nozomi; Higashihara, Masaaki; Honma, Yoshio

    2002-08-01

    When cells were incubated in the presence of both interferon-gamma (IFN-gamma) and all-trans retinoic acid (ATRA), the concentration of IFN-gamma required to induce apoptosis of B-cell lymphoma cells was much lower than that required for myeloid or erythroid cell lines. The concentration of IFN-gamma that effectively inhibited the proliferation of BALM-3 cells was 1/40 of that required for BALM-1 cells. STAT-1 phosphorylation, IRF-1 mRNA and protein expression and RAR-beta expression were enhanced to a greater degree in BALM-3 cells treated with IFN-gamma and ATRA than in BALM-1 cells treated with IFN-gamma and ATRA, suggesting that these IFN-gamma related genes were involved in the induction of apoptosis of BALM-3 cells. PMID:12191570

  2. AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells.

    PubMed

    Jing, Yue; Wang, Gang; Ge, Ying; Xu, Minjie; Tang, Shuainan; Gong, Zhunan

    2016-01-01

    Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy. PMID:27073325

  3. AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells

    PubMed Central

    Jing, Yue; Wang, Gang; Ge, Ying; Xu, Minjie; Tang, Shuainan; Gong, Zhunan

    2016-01-01

    Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy. PMID:27073325

  4. Retinoic acid alone and in combination with cytosine arabinoside induces differentiation of human myelomonocytic and monoblastic leukaemic cells.

    PubMed

    Hassan, H T; Rees, J K

    1988-01-01

    The effect of retinoic acid (RA) alone and in combination with cytosine arabinoside (Ara-C) on differentiation of fresh human myeloid leukaemic cells from patients with AML was studied. Cells from six patients: three with acute myelomonocytic leukaemia AMMoL and three with acute monoblastic leukaemia AMoL with a percentage of blasts greater than 70, were treated in an in vitro primary suspension culture with retinoic acid (10(-7) M), cytosine arabinoside (100 ng/ml) or both in combination. Non-adherent mononuclear cells were seeded at a concentration of 5 x 10(5) cells/ml in RPMI 1640 culture medium supplemented with 20 per cent fetal bovine serum and 10 per cent (PHA-LCM) phytohaemagglutinin leucocyte conditioned medium and incubated for 6 days at 37 degrees C in a humidified incubator containing 5 per cent CO2 in air. Morphological and functional differentiation into terminal mature elements was induced in all leukaemia cells of the six patients following exposure to the combination of both agents. These results suggest the potential usefulness of the combination of a differentiating agent (retinoic acid) and an antileukaemic drug (cytosine arabinoside) in the treatment of acute myeloid leukaemias: AMMoL and AMoL. This combination warrants a clinical trial. PMID:3422632

  5. c9, t11- conjugated linoleic acid induces HCC cell apoptosis and correlation with PPAR-γ signaling pathway

    PubMed Central

    Lu, Guozhong; Zhang, Guoqing; Zheng, Xing; Zeng, Yan; Xu, Ziqi; Zeng, Weichi; Wang, Kebing

    2015-01-01

    Objective: Cis9, trans11 conjugated linoleic acid (c9, t11-CLA.) is one of the most important isomers of conjugated linoleic acid, which have a strong anti-tumor effects. Based on previous studies, we further explored the molecular mechanism of inducing cells apoptosis in human hepatocellular carcinoma cell line HepG2 and Hep3B. Methods: Cell Counting Kit 8 (CCK-8) assay was used to investigate the effects of c9, t11-CLA on cell viability and cell proliferation ability; The effects of c9, t11-CLA on cell apoptosis was analyzed by DNA ladder assay, immuno-fluorescence and flow cytometry, respectively. Apoptotic related gene (Bcl-2, Bcl-XL, Bcl-w, Mcl-1, Bax, Bak, Bad, Bid and Bim), PPAR family member (PPAR-α, PPAR-β and PPAR-γ), and Cox2 mRNA and protein expression were analyzed by RT-PCR and western blotting. ELISA assay was used to detect the content of Caspase-3. Results: Our data were confirmed that c9, t11-CLA could inhibit the HCC cells proliferation ability and decrease the cells viability. RT-PCR and western blotting assay verified that c9, t11-CLA obviously increased the transcription and protein expression levels of PPAR-γ. The synchronism and correlation between PPAR-γ and apoptotic proteins Bcl-2, Bax and Caspase-3 were found with a dose- and time-dependent manner. PPAR-γ inhibitor GW9662 and activator Rosilitazone were further verified that there was cooperative relation between them. Conclusion: In our study, we first report that c9, t11-CLA induces apoptosis in HCC cells by activation of PPARγ-Bcl-2-Caspase-3 signal pathway. These results indicated that c9, t11-CLA will be useful for clinic therapy of anti-tumor and as a new regulator of PPAR-γ in the future. PMID:26885272

  6. Increased cell loss in the human jejunum induced by laxatives (ricinoleic acid, dioctyl sodium sulphosuccinate, magnesium sulphate, bile salts).

    PubMed Central

    Bretagne, J F; Vidon, N; L'Hirondel, C; Bernier, J J

    1981-01-01

    Two conjugated bile salts (10 mmol/l sodium glycocholate, 10 mmol/l sodium taurodeoxycholate) and three laxatives (30 mmol/l magnesium sulphate, 10 mmol/l ricinoleic acid, 2 mmol/l dioctyl sodium sulphosuccinate) were tested on seven subjects with no intestinal lesions in 14 experiments by intestinal perfusion of the jejunum. A 25 cm segment was studied. Each solution was perfused at the rate of 10 ml/min. Water and electrolyte fluxes, losses of deoxyribonucleic acid (DNA), and intestinal cell enzyme activity were measured in the fluids collected. All the laxatives and bile salts tested (except sodium glycocholate) induced water and electrolyte secretion, a rise in intraluminal DNA loss, and enzyme activity. It was possible to establish a significant correlation (p less than 0.001) between the amounts of water fluxes and DNA loss under the effect of dioctyl sodium sulphosuccinate and ricinoleic acid. PMID:6165655

  7. Gibberellic-acid-induced cell elongation in pea epicotyls: Effect on polyploidy and DNA content.

    PubMed

    Boeken, G; Van Oostveldt, P

    1977-01-01

    In gibberellic-acid(GA3)-treated epicotyls of dwarf peas (Pisum sativum L.) grown in the light, DNA (per cell and per epicotyl) is followed. Histofluorometric DNA determinations show that GA3-promoted cell elongation is not accompanied by increased endomitosis, but chemical estimations show an increased DNA content per epicotyl. This difference must therefore be the result of increased mitotic activity in the GA3-treated tissue. Epicotyls of seedlings grown with or without cotyledons under continuous light with GA3 are tetraploid, as are those of ecotylized embryos grown in darkness. These epicotyls reach no more than half the length of octaploid epicotyls of seedlings grown in darkness. This result provides evidence for a relationship between polyploidy and final possible cell length. PMID:24419898

  8. Mitochondrial genome depletion in human liver cells abolishes bile acid-induced apoptosis: role of the Akt/mTOR survival pathway and Bcl-2 family proteins.

    PubMed

    Marin, Jose J G; Hernandez, Alicia; Revuelta, Isabel E; Gonzalez-Sanchez, Ester; Gonzalez-Buitrago, Jose M; Perez, Maria J

    2013-08-01

    Acute accumulation of bile acids in hepatocytes may cause cell death. However, during long-term exposure due to prolonged cholestasis, hepatocytes may develop a certain degree of chemoresistance to these compounds. Because mitochondrial adaptation to persistent oxidative stress may be involved in this process, here we have investigated the effects of complete mitochondrial genome depletion on the response to bile acid-induced hepatocellular injury. A subline (Rho) of human hepatoma SK-Hep-1 cells totally depleted of mitochondrial DNA (mtDNA) was obtained, and bile acid-induced concentration-dependent activation of apoptosis/necrosis and survival signaling pathways was studied. In the absence of changes in intracellular ATP content, Rho cells were highly resistant to bile acid-induced apoptosis and partially resistant to bile acid-induced necrosis. In Rho cells, both basal and bile acid-induced generation of reactive oxygen species (ROS), such as hydrogen peroxide and superoxide anion, was decreased. Bile acid-induced proapoptotic signals were also decreased, as evidenced by a reduction in the expression ratios Bax-α/Bcl-2, Bcl-xS/Bcl-2, and Bcl-xS/Bcl-xL. This was mainly due to a downregulation of Bax-α and Bcl-xS. Moreover, in these cells the Akt/mTOR pathway was constitutively activated in a ROS-independent manner and remained similarly activated in the presence of bile acid treatment. In contrast, ERK1/2 activation was constitutively reduced and was not activated by incubation with bile acids. In conclusion, these results suggest that impaired mitochondrial function associated with mtDNA alterations, which may occur in liver cells during prolonged cholestasis, may activate mechanisms of cell survival accounting for an enhanced resistance of hepatocytes to bile acid-induced apoptosis. PMID:23597504

  9. Molecular mechanism of cell death induced by king cobra (Ophiophagus hannah) venom l-amino acid oxidase.

    PubMed

    Fung, Shin Yee; Lee, Mui Li; Tan, Nget Hong

    2015-03-01

    Snake venom LAAOs have been reported to exhibit a wide range of pharmacological activities, including cytotoxic, edema-inducing, platelet aggregation-inducing/platelet aggregation-inhibiting, bactericidal and antiviral activities. A heat-stable form of l-amino acid oxidase isolated from king cobra (Ophiophagus hannah) venom (OH-LAAO) has been shown to exhibit very potent cytotoxicity against human tumorigenic cells but not in their non-tumorigenic counterparts, and the cytotoxicity was due to the apoptosis-inducing effect of the enzyme. In this work, the molecular mechanism of cell death induced by OH-LAAO was investigated. The enzyme exerts its apoptosis-inducing effect presumably via both intrinsic and extrinsic pathways as suggested by the increase in caspase-8 and -9 activities. Oligonucleotide microarray analysis showed that the expression of a total of 178 genes was significantly altered as a result of oxidative stress induced by the hydrogen peroxide generated by the enzyme. Of the 178 genes, at least 27 genes are involved in apoptosis and cell death. These alterations of gene expression was presumably caused by the direct cytotoxic effect of H2O2 generated during the enzymatic reaction, as well as the non-specific oxidative modifications of signaling molecules that eventually lead to apoptosis and cell death. The very substantial up-regulation of cytochrome P450 genes may also contribute to the potent cytotoxic action of OH-LAAO by producing excessive reactive oxygen species (ROS). In conclusion, the potent apoptosis inducing activity of OH-LAAO was likely due to the direct cytotoxic effect of H2O2 generated during the enzymatic reaction, as well as the non-specific oxidation of signalling molecules. PMID:25615711

  10. Gallic acid induces apoptosis in human cervical epithelial cells containing human papillomavirus type 16 episomes.

    PubMed

    Shi, Lin; Lei, Yanjun; Srivastava, Ranjana; Qin, Weihua; Chen, Jason J

    2016-01-01

    The high-risk human papillomaviruses (HPV) that infect the anogenital tract are strongly associated with the development of cervical carcinoma, which is the second most common cancer in women worldwide. Therapeutic drugs specifically targeting HPV are not available. Polyphenolic compounds have gained considerable attention because of their cytotoxic effects against a variety of cancers and certain viruses. In this study, we examined the effects of several polyphenols on cellular proliferation and death of the human cervical cancer cells and human cervical epithelial cells containing stable HPV type 16 episomes (HPVep). Our results show that three polyphenols inhibited proliferation of HeLa cells dose-dependently. Furthermore, one of the examined polyphenols, gallic acid (GA), also inhibited the proliferation of HPVep cells and exhibited significant specificity towards HPV-positive cells. The anti-proliferative effect of GA on HPVep and HeLa cells was associated with apoptosis and upregulation of p53. These results suggest that GA can be a potential candidate for the development of anti-HPV agents. PMID:26059022

  11. Ursolic acid from Trailliaedoxa gracilis induces apoptosis in medullary thyroid carcinoma cells

    PubMed Central

    AGUIRIANO-MOSER, VICTOR; SVEJDA, BERNHARD; LI, ZENG-XIA; STURM, SONJA; STUPPNER, HERMANN; INGOLIC, ELISABETH; HÖGER, HARALD; SIEGL, VERONIKA; MEIER-ALLARD, NATHALIE; SADJAK, ANTON; PFRAGNER, ROSWITHA

    2015-01-01

    Medullary thyroid carcinoma (MTC) originates from the C-cells of the thyroid and is not sensitive to radiation or chemotherapy. Therefore, surgical removal of the tumor tissue in its entirety is the only curative treatment for MTC. The present study aimed to examine the potential mechanisms of action of extracts of Trailliaedoxa gracilis (TG; WW Smith & Forrest), a plant from the province of Sichuan, China, and of ursolic acid (UA), a pentacyclic triterpen present in TG, on the MTC-SK MTC cell line. A total of 13 TG fractions and UA were examined in vitro for their effects on cell morphology, cell number, proliferation and rates of apoptosis. Reverse transcription-quantitative polymerase chain reaction of nuclear factor-κB essential modifier (NEMO) was performed to delineate the role of the apoptotic pathway following treatment with UA. TG and UA were examined in vivo in xenotransplanted MTC-bearing severe combined immunodeficient mice. The TG fractions exhibited antiproliferative effects, with inhibition of mitochondrial activity in the tumor cells at concentrations, which caused no impairment of the normal control cells. The apoptotic rates of the MTC-SK cells treated with the TG fractions and UA were determined, in which no marked tumor inhibition was observed in the treated MTC-mice, and no change in the expression of NEMO was detected in the treated MTC-SK cells. The observation of early-onset activation of caspase 8 suggested that the responsible factor was linked to NEMO, an anti-apoptotic protein. However, no differences in the mRNA transcription levels of NEMO were detected in MTC-SK cells treated with UA, suggesting that this protein was not associated with the signal transducer and activator of transcription 3 pathway. PMID:26151624

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

    SciTech Connect

    Deshpande, Vaidehee S. . E-mail: vaidehee@hotmail.com; Kehrer, James P.

    2006-08-01

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

  13. New in vitro insights on a cell death pathway induced by magnolol and honokiol in aristolochic acid tubulotoxicity.

    PubMed

    Bunel, Valérian; Antoine, Marie-Hélène; Stévigny, Caroline; Nortier, Joëlle; Duez, Pierre

    2016-01-01

    Aristolochic acids (AA) are nephrotoxic agents found in Aristolochia species whose consumption leads to the onset of a progressive tubulointerstitial fibrosis. This AA-nephropathy was first reported during the Belgian outbreak of the 1990's in which more than a hundred patients consumed slimming pills containing an Aristolochia species and Magnolia officinalis. The patients developed an end-stage kidney disease requiring dialysis or transplantation. Magnolol and honokiol are bioactive compounds from M. officinalis known for their potent antioxidant activity. As they can alleviate oxidative stress, we investigated their respective effects on AA-mediated tubulotoxicity using HK-2 cells. Magnolol and honokiol were able to reduce the oxidative stress associated with AA-treatment. Cytotoxicity alleviation was further investigated and overall cell viability measurements unexpectedly revealed that both compounds worsened the survival of AA-treated cells. Flow cytometry analyses of annexin V/PI stained cells indicated that the lignans efficiently prevented AA-induced apoptosis; but favored necrosis. Microscopy observations highlighted extensive vacuolization; other types of cell death, including autophagy, paraptosis or accelerated senescence were excluded. Ki-67 index and cell cycle analysis indicated that both magnolol and honokiol inhibited proliferation by blocking the cell cycle at the G1 phase; they also prevented the AA-induced G2/M arrest. PMID:26631295

  14. [Apoptosis-inducing effect of valproic acid combined with arsenic trioxide on RPMI 8226 cells and its mechanism].

    PubMed

    Wang, Xiao-Ning; Zhang, Mei

    2014-08-01

    This study was aimed to investigate the apoptosis-inducing effect of valproic acid (VPA) combined with arsenic trioxide (ATO) on human multiple myeloma RPMI 8226 cells and its mechanism. The cell proliferation of RPMI 8226 cells was assayed by CCK-8 method. The cell apoptosis were detected by flow cytometry. Semiquantitative RT-PCR and Western blot were applied respectively to detect the mRNA and protein expression level of BCL-2, BAX, caspase-8 and caspase-9 gene. The results showed that both the VPA and ATO inhibited RPMI 8226 cell proliferation. The combination of ATO and VPA has synergistic effect (Q values greater than 1.15). The RPMI 8226 cell apoptosis rate in combined drug group was significantly higher than that in single drug group (P < 0.05). The mRNA and protein expressions of BCL-2 gene in combined drug group decreased, while the mRNA and protein expressions of BAX, caspase-8 and caspase-9 significantly increased, compared with single drug group (P < 0.05) . It is concluded that VPA can enhance the sensitivity of RPMI 8226 cells to ATO-induced apoptosis, which may be associated with decreasing the BCL-2 expression and increasing the BAX, caspase-8 and caspase-9 gene expression. PMID:25130820

  15. Triplex-forming Peptide Nucleic Acids Induce Heritable Elevations in Gamma-globin Expression in Hematopoietic Progenitor Cells

    PubMed Central

    Chin, Joanna Y; Reza, Faisal; Glazer, Peter M

    2013-01-01

    Potentiating homologous recombination using triplex-forming peptide nucleic acids (PNAs) can be used to mediate targeted sequence editing by donor DNAs and thereby induce functional gene expression to supplant non-functional counterparts. Mutations that disrupt the normal function of the β-globin subunit cause hemoglobinopathies such as sickle cell disease and β-thalassemias. However, expression of the functional γ-globin subunit in adults, a benign condition called hereditary persistence of fetal hemoglobin (HPFH), can ameliorate the severity of these disorders, but this expression is normally silenced. Here, we harness triplex-forming PNA-induced donor DNA recombination to create HPFH mutations that increase the expression of γ-globin in adult mammalian cells, including β-yeast artificial chromosome (YAC) bone marrow and hematopoietic progenitor cells (HPCs). Transfection of human cells led to site-specific modification frequencies of 1.63% using triplex-forming PNA γ-194-3K in conjunction with donor DNAs, compared with 0.29% using donor DNAs alone. We also concurrently modified the γ-globin promoter to insert both HPFH-associated point mutations and a hypoxia-responsive element (HRE), conferring increased expression that was also regulated by oxygen tension. This work demonstrates application of oligonucleotide-based gene therapy to induce a quiescent gene promoter in mammalian cells and regulate its expression via an introduced HRE transcription factor binding site for potential therapeutic purposes. PMID:23337982

  16. The N-acetylcysteine-insensitive acetic acid-induced yeast programmed cell death occurs without macroautophagy.

    PubMed

    Antonacci, Lucia; Guaragnella, Nicoletta; Ždralevic, Maša; Passarella, Salvatore; Marra, Ersilia; Giannattasio, Sergio

    2012-12-01

    Programmed cell death can occur through two separate pathways caused by treatment of Saccharomyces cerevisiae with acetic acid (AA-PCD), which differ from one another essentially with respect to their sensitivity to N-acetylcysteine (NAC) and to the role played by cytochrome c and metacaspase YCA1. Moreover, yeast can also undergo macroautophagy which occurs in NAC-insensitive manner. In order to gain some insight into the relationship between AA-PCD and macroautophagy use was made of WT and knock-out cells lacking YCA1 and/or cytochrome c. We show that i. macroautophagy is modulated by YCA1 and by cytochrome c in a negative and positive manner, respectively, ii. the NAC-insensitive AA-PCD and macroautophagy differ from one another and iii. NAC-insensitive AA-PCD pathway takes place essentially without macroautophagy, even if the shift of extracellular pH to acidic values required for AA-PCD to occur leads itself to increased or decreased macroautophagy in YCA1 or cytochrome c-lacking cells. PMID:23072389

  17. Deficient glutathione in guard cells facilitates abscisic acid-induced stomatal closure but does not affect light-induced stomatal opening.

    PubMed

    Jahan, Md Sarwar; Ogawa, Ken'ichi; Nakamura, Yoshimasa; Shimoishi, Yasuaki; Mori, Izumi C; Murata, Yoshiyuki

    2008-10-01

    We investigated the role of glutathione (GSH) in stomatal movements using a GSH deficient mutant, chlorinal-1 (ch1-1). Guard cells of ch1-1 mutants accumulated less GSH than wild types did. Light induced stomatal opening in ch1-1 and wild-type plants. Abscisic acid (ABA) induced stomatal closure in ch1-1 mutants more than wild types without enhanced reactive oxygen species (ROS) production. Therefore, GSH functioned downstream of ROS production in the ABA signaling cascade. PMID:18838781

  18. Suberoylanilide hydroxamic acid (SAHA) inhibits EGF-induced cell transformation via reduction of cyclin D1 mRNA stability

    SciTech Connect

    Zhang, Jingjie; Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York; Li, Xuejun; Huang, Chuanshu

    2012-09-01

    Suberoylanilide hydroxamic acid (SAHA) inhibiting cancer cell growth has been associated with its downregulation of cyclin D1 protein expression at transcription level or translation level. Here, we have demonstrated that SAHA inhibited EGF-induced Cl41 cell transformation via the decrease of cyclin D1 mRNA stability and induction of G0/G1 growth arrest. We found that SAHA treatment resulted in the dramatic inhibition of EGF-induced cell transformation, cyclin D1 protein expression and induction of G0/G1 growth arrest. Further studies showed that SAHA downregulation of cyclin D1 was only observed with endogenous cyclin D1, but not with reconstitutionally expressed cyclin D1 in the same cells, excluding the possibility of SAHA regulating cyclin D1 at level of protein degradation. Moreover, SAHA inhibited EGF-induced cyclin d1 mRNA level, whereas it did not show any inhibitory effect on cyclin D1 promoter-driven luciferase reporter activity under the same experimental conditions, suggesting that SAHA may decrease cyclin D1 mRNA stability. This notion was supported by the results that treatment of cells with SAHA decreased the half-life of cyclin D1 mRNA from 6.95 h to 2.57 h. Consistent with downregulation of cyclin D1 mRNA stability, SAHA treatment also attenuated HuR expression, which has been well-characterized as a positive regulator of cyclin D1 mRNA stability. Thus, our study identifies a novel mechanism responsible for SAHA inhibiting cell transformation via decreasing cyclin D1 mRNA stability and induction of G0/G1 growth arrest in Cl41 cells. -- Highlights: ► SAHA inhibits cell transformation in Cl41 cells. ► SAHA suppresses Cyclin D1 protein expression. ► SAHA decreases cyclin D1 mRNA stability.

  19. Effects of cyclopiazonic acid and dexamethasone on serotonin-induced calcium responses in vascular smooth muscle cells.

    PubMed

    Selli, Cigdem; Tosun, Metiner

    2016-06-01

    We previously observed that sarcoendoplasmic reticulum Ca(2+) ATPase (SERCA) blockade by cyclopiazonic acid (CPA) significantly potentiates serotonin (5-hydroxytryptamine (5-HT))-induced vascular contractions. Furthermore, 5-HT receptor antagonist methysergide partially inhibited CPA-potentiated 5-HT contractions. In the present study, we further investigated whether SERCA inhibition potentiates 5-HT-induced Ca(2+) responses along with attenuating the receptor antagonism by store-operated Ca(2+) (SOC) entry and protein kinase C (PKC)-mediated mechanisms. The effects of dexamethasone that was previously shown to induce SOC entry and enhance 5-HT responses were also tested. For this purpose, intracellular Ca(2+) levels were monitored in A7r5 embryonic rat vascular smooth muscle cells by spectrofluorometry using the fluorescent indicator fura-2. The results showed that CPA, although not dexamethasone, significantly potentiated 5-HT-induced Ca(2+) elevations. Ketanserin partially decreased 5-HT-induced and CPA-potentiated Ca(2+) elevations whereas both PKC inhibitor D-sphingosine and SOC entry blocker 2-aminoethoxydiphenyl borate (2-APB) abolished the remaining responses. The data suggests that diminished antagonistic effect on 5-HT-induced Ca(2+) elevations in the presence of SERCA inhibition is induced by SOC entry and PKC activation. PMID:26944908

  20. Palmitic acid induces interleukin-1β secretion via NLRP3 inflammasomes and inflammatory responses through ROS production in human placental cells.

    PubMed

    Shirasuna, Koumei; Takano, Hiroki; Seno, Kotomi; Ohtsu, Ayaka; Karasawa, Tadayoshi; Takahashi, Masafumi; Ohkuchi, Akihide; Suzuki, Hirotada; Matsubara, Shigeki; Iwata, Hisataka; Kuwayama, Takehito

    2016-08-01

    Maternal obesity, a major risk factor for adverse pregnancy complications, results in inflammatory cytokine release in the placenta. Levels of free fatty acids are elevated in the plasma of obese human. These fatty acids include obesity-related palmitic acids, which is a major saturated fatty acid, that promotes inflammatory responses. Increasing evidence indicates that nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasomes mediate inflammatory responses induced by endogenous danger signals. We hypothesized that inflammatory responses associated with gestational obesity cause inflammation. To test this hypothesis, we investigated the effect of palmitic acid on the activation of NLRP3 inflammasomes and inflammatory responses in a human Sw.71 trophoblast cell line. Palmitic acid stimulated caspase-1 activation and markedly increased interleukin (IL)-1β secretion in Sw.71 cells. Treatment with a caspase-1 inhibitor diminished palmitic acid-induced IL-1β release. In addition, NLRP3 and caspase-1 genome editing using a CRISPR/Cas9 system in Sw.71 cells suppressed IL-1β secretion, which was stimulated by palmitic acid. Moreover, palmitic acid stimulated caspase-3 activation and inflammatory cytokine secretion (e.g., IL-6 and IL-8). Palmitic acid-induced cytokine secretion were dependent on caspase-3 activation. In addition, palmitic acid-induced IL-1β, IL-6, and IL-8 secretion was depended on reactive oxygen species (ROS) generation. In conclusion, palmitic acid caused activation of NLRP3 inflammasomes and inflammatory responses, inducing IL-1β, IL-6, and IL-8 secretion, which is associated with ROS generation, in human Sw.71 placental cells. We suggest that obesity-related palmitic acid induces placental inflammation, resulting in association with pregnancy complications. PMID:27300134

  1. Bone morphogenetic protein 4 and retinoic acid trigger bovine VASA homolog expression in differentiating bovine induced pluripotent stem cells.

    PubMed

    Malaver-Ortega, Luis F; Sumer, Huseyin; Jain, Kanika; Verma, Paul J

    2016-02-01

    Primordial germ cells (PGCs) are the earliest identifiable and completely committed progenitors of female and male gametes. They are obvious targets for genome editing because they assure the transmission of desirable or introduced traits to future generations. PGCs are established at the earliest stages of embryo development and are difficult to propagate in vitro--two characteristics that pose a problem for their practical application. One alternative method to enrich for PGCs in vitro is to differentiate them from pluripotent stem cells derived from adult tissues. Here, we establish a reporter system for germ cell identification in bovine pluripotent stem cells based on green fluorescent protein expression driven by the minimal essential promoter of the bovine Vasa homolog (BVH) gene, whose regulatory elements were identified by orthologous modelling of regulatory units. We then evaluated the potential of bovine induced pluripotent stem cell (biPSC) lines carrying the reporter construct to differentiate toward the germ cell lineage. Our results showed that biPSCs undergo differentiation as embryoid bodies, and a fraction of the differentiating cells expressed BVH. The rate of differentiation towards BVH-positive cells increased up to tenfold in the presence of bone morphogenetic protein 4 or retinoic acid. Finally, we determined that the expression of key PGC genes, such as BVH or SOX2, can be modified by pre-differentiation cell culture conditions, although this increase is not necessarily mirrored by an increase in the rate of differentiation. PMID:26660942

  2. Increased betulinic acid induced cytotoxicity and radiosensitivity in glioma cells under hypoxic conditions

    PubMed Central

    2011-01-01

    Background Betulinic acid (BA) is a novel antineoplastic agent under evaluation for tumor therapy. Because of the selective cytotoxic effects of BA in tumor cells (including gliomas), the combination of this agent with conservative therapies (such as radiotherapy and chemotherapy) may be useful. Previously, the combination of BA with irradiation under hypoxic conditions had never been studied. Methods In this study, the effects of 3 to 30 μM BA on cytotoxicity, migration, the protein expression of PARP, survivin and HIF-1α, as well as radiosensitivity under normoxic and hypoxic conditions were analyzed in the human malignant glioma cell lines U251MG and U343MG. Cytotoxicity and radiosensitivity were analyzed with clonogenic survival assays, migration was analyzed with Boyden chamber assays (or scratch assays) and protein expression was examined with Western blot analyses. Results Under normoxic conditions, a half maximal inhibitory concentration (IC50) of 23 μM was observed in U251MG cells and 24 μM was observed in U343MG cells. Under hypoxic conditions, 10 μM or 15 μM of BA showed a significantly increased cytotoxicity in U251MG cells (p = 0.004 and p = 0.01, respectively) and U343MG cells (p < 0.05 and p = 0.01, respectively). The combination of BA with radiotherapy resulted in an additive effect in the U343MG cell line under normoxic and hypoxic conditions. Weak radiation enhancement was observed in U251MG cell line after treatment with BA under normoxic conditions. Furthermore, under hypoxic conditions, the incubation with BA resulted in increased radiation enhancement. The enhancement factor, at an irradiation dose of 15 Gy after treatment with 10 or 15 μM BA, was 2.20 (p = 0.02) and 4.50 (p = 0.03), respectively. Incubation with BA led to decreased cell migration, cleavage of PARP and decreased expression levels of survivin in both cell lines. Additionally, BA treatment resulted in a reduction of HIF-1α protein under hypoxic conditions. Conclusion Our

  3. Gambogic acid induces mitochondria-dependent apoptosis by modulation of Bcl-2 and Bax in mantle cell lymphoma JeKo-1 cells

    PubMed Central

    Xu, Jingyan; Zhou, Min; Wang, Jing; Zhang, Qiguo; Xu, Yong; Xu, Yueyi; Zhang, Qian; Xu, Xihui; Zeng, Hui

    2013-01-01

    Objective To study the mechanisms in gambogic acid (GA) -induced JeKo-1 human Mantle Cell Lymphoma cell apoptosis in vitro. Methods The proliferation of GA-treated JeKo-1 cells was measured by CCK-8 assay and Ki-67 immunocytochemical detection. Apoptosis, cell cycle and mitochondrial membrane potential were measured by flow cytometric analysis. Caspase-3, -8 and -9 were detected by colorimetric assay. Bcl-2 and Bax were analyzed by Western blotting. Results GA inhibited cell growth in a time- and dose- dependent manner. GA induces apoptosis in JeKo-1 cells but not in normal bone marrow cells, which was involved in reducing the membrane potential of mitochondria, activating caspases-3, -8 and -9 and decreasing the ratio of Bcl-2 and Bax without cell cycle arresting. Conclusions GA induced apoptosis in human MCL JeKo-1 cells by regulating Bcl-2/Bax and activating caspase-3, -8 and -9 via mitochondrial pathway without affecting cell cycle. PMID:23592899

  4. Corosolic acid analogue, a natural triterpenoid saponin, induces apoptosis on human hepatocarcinoma cells through mitochondrial pathway in vitro.

    PubMed

    Qu, Liping; Zhang, Huiqing; Yang, Yanlong; Yang, Geliang; Xin, Hailiang; Ling, Changquan

    2016-08-01

    Context 2a,-3a,-24-Trihydroxyurs-12-en-28-oic acid (TEO, a corosolic acid analogue) is a triterpenoid saponin isolated from Actinidia valvata Dunn (Actinidiaceae), a well-known traditional Chinese medicine. Objective This study investigated the anti-proliferation and inducing apoptosis effects of TEO in three human hepatocellular carcinoma (HCC) cell lines. Materials and methods Cytotoxic activity of TEO was determined by the MTT assay at various concentrations from 2.5 to 40 μg/mL in BEL-7402, BEL-7404 and SMMC-7721 cell lines. Cell morphology was assessed by acridine orange/ethidium bromide and 4'-6-diamidino-2-phenylindole dihydrochloride staining and fluorescence microscopy. Cell-cycle distribution and DNA damage were determined by flow cytometry and comet assay. Mitochondrial dysfunction was assessed by JC-1 staining and transmission electron microscopy. Apoptosis changes were explored by Western blot, TNF-α and caspase-3, -8, -9 assays. Results TEO exhibited inhibition effects on BEL-7402, BEL-7404 and SMMC-7721 cells treated for 24 h, the IC50 values were 34.6, 30.8 and 30.5 μg/mL, respectively. TEO (40 μg/mL)-treated three cell lines increased by more than 21% in the G1 phase and presented the morphological change and DNA damage. TEO also declined the mitochondrial membrane potential and altered mitochondrial ultra-structure. Furthermore, caspase-3, caspase-8, caspase-9 and TNF-α were also activated. Mechanism investigation showed that TEO could decrease anti-apoptotic Bcl-2 protein expression, increase proapoptotic Bax and Bid proteins expressions and increase Bax/Bcl-2 ratio. Conclusion Our results demonstrate for the first time that TEO inhibited growth of HCC cell lines and induced G1 phase arrest. Moreover, proapoptotic effects of TEO were mediated through the activation of TNF-α, caspases and mitochondrial pathway. PMID:26810384

  5. Cholinergic activation enhances retinoic acid-induced differentiation in the human NB-4 acute promyelocytic leukemia cell line.

    PubMed

    Chotirat, Sadudee; Suriyo, Tawit; Hokland, Marianne; Hokland, Peter; Satayavivad, Jutamaad; Auewarakul, Chirayu U

    2016-07-01

    The non-neuronal cholinergic system (NNCS) has been shown to play a role in regulating hematopoietic differentiation. We determined the expression of cholinergic components in leukemic cell lines by Western blotting and in normal leukocyte subsets by flow cytometry and found a heterogeneous expression of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), choline transporter (CHT), M3 muscarinic acetylcholine receptor (M3-mAChR) and α7 nicotinic acetylcholine receptor (α7-nAChR). We then evaluated NNCS role in differentiation of human NB-4 acute promyelocytic leukemia cell line and discovered a dramatic induction of M3-mAChR after all-trans retinoic acid (ATRA) treatment (p<0.0001). Adding carbachol which is a cholinergic agonist to the ATRA treatment resulted in an increase of a granulocytic differentiation marker (CD11b) as compared with ATRA treatment alone (p<0.05), indicating that cholinergic activation enhanced ATRA in inducing NB-4 maturation. The combination of carbachol and ATRA treatment for 72h also resulted in decreased viability and increased cleaved caspase-3 expression when compared with ATRA treatment alone (p<0.05). However, this combination did not cause poly (ADP-ribose) polymerase (PARP) cleavage. Overall, we have shown that NB-4 cells expressed M3-mAChR in a differentiation-dependent manner and cholinergic stimulation induced maturation and death of ATRA-induced differentiated NB-4 cells. PMID:27282572

  6. Enhancement of caffeic acid phenethyl ester on all-trans retinoic acid-induced differentiation in human leukemia HL-60 cells

    SciTech Connect

    Kuo, H.-C.; Kuo, W.-H.; Lee, Y.-J.; Wang, C.-J.; Tseng, T.-H. . E-mail: tht@csmu.edu.tw

    2006-10-01

    All-trans retinoic acid (ATRA) induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL); however, the response is sometimes very slow. Furthermore, relapse and resistance to treatment often occur despite continued treatment with ATRA. Thereafter, combination treatment strategies have been suggested to circumvent these problems. The present study demonstrates that caffeic acid phenethyl ester (CAPE), a major component of honeybee propolis, enhanced ATRA-induced granulocytic differentiation in HL-60, a human promyelocytic cell line. The differentiation was assessed by Wright-Giemsa stain, nitroblue tetrazolium reduction, and membrane differentiation marker CD11b. In addition, CAPE enhanced ATRA-induced cell cycle arrest at the G1 phase by decreasing the association of cdk2-cyclin E complex. Finally, it was demonstrated that CAPE promoted the ATRA-mediated nuclear transcription activation of RAR{alpha} assessed by EMSA assay and enhanced the expression of target genes including RAR{alpha}, C/EBP{epsilon}, and p21 protein resulting in the differentiation development of leukemia. It is suggested that CAPE possesses the potential to enhance the efficiency of ATRA in the differentiation therapy of APL.

  7. Lysophosphatidic acid-induced calcium mobilization and proliferation in kidney proximal tubular cells.

    PubMed

    Dixon, R J; Young, K; Brunskill, N J

    1999-02-01

    Patients with proteinuria tend to develop progressive renal disease with proximal tubular cell atrophy and interstitial scarring. It has been suggested that the nephrotoxicity of albuminuric states may be due to the protein molecule itself or by lipids, such as lysophosphatidic acid (LPA), that albumin carries. LPA was found to cause a transient increase in intracytoplasmic free Ca2+ ([Ca2+]i) in opossum kidney proximal tubule cells (OK) that was maximal at 100 microM LPA and was dose dependent with an EC50 of 2.6 x 10(-6) M. This Ca2+ mobilization was from both internal stores and across the plasma membrane and was pertussis toxin (PTX) insensitive. Treatment of OK cells with 100 microM LPA for 5 min was found to cause a twofold increase in [3H]thymidine incorporation and a three- to fivefold increase over control after 24 h. This was highly PTX sensitive and insensitive to pretreatment with the tyrosine kinase inhibitors genistein and herbimycin A. These findings may be of significance in the progression of renal disease and indicate the potential importance of lipids in modulating proximal tubule cell function and growth. PMID:9950949

  8. The heme precursor 5-aminolevulinic acid disrupts the Warburg effect in tumor cells and induces caspase-dependent apoptosis.

    PubMed

    Sugiyama, Yuta; Hagiya, Yuichiro; Nakajima, Motowo; Ishizuka, Masahiro; Tanaka, Tohru; Ogura, Shun-Ichiro

    2014-03-01

    Our previous study demonstrated that 5-aminolevulinic acid (ALA) administered to mice stimulates oxidative phosphorylation by upregulation of the mitochondrial respiratory chain complex IV enzyme cytochrome c oxidase (COX). The present study investigated whether ALA disrupts the Warburg effect, which represents a shift in ATP generation from oxidative phosphorylation to glycolysis, protecting tumor cells against oxidative stress-mediated apoptosis. The human lung carcinoma cell line A549 exposed to ALA exhibited enhanced oxidative phosphorylation, which was indicated by an increase in COX protein expression and oxygen consumption. Furthermore, ALA suppressed glycolysis-mediated acidosis. This normalization of the ATP metabolic pathways significantly increased the generation of superoxide anion radical (O2•-) and the functional expression of active caspase-3, leading to caspase-dependent apoptosis. These data demonstrate that ALA inhibits the Warburg effect and induces cancer cell death. Use of this endogenous compound might constitute a novel approach to cancer therapy. PMID:24366173

  9. Light-harvesting complexes in photosystem II regulate glutathione-induced sensitivity of Arabidopsis guard cells to abscisic acid.

    PubMed

    Jahan, Md Sarwar; Nozulaidi, Mohd; Khairi, Mohd; Mat, Nashriyah

    2016-05-20

    Light-harvesting complexes (LHCs) in photosystem II (PSII) regulate glutathione (GSH) functions in plants. To investigate whether LHCs control GSH biosynthesis that modifies guard cell abscisic acid (ABA) sensitivity, we evaluated GSH content, stomatal aperture, reactive oxygen species (ROS), weight loss and plant growth using a ch1-1 mutant that was defective of LHCs and compared this with wild-type (WT) Arabidopsis thaliana plants. Glutathione monoethyl ester (GSHmee) increased but 1-chloro-2,4 dinitrobenzene (CDNB) decreased the GSH content in the guard cells. The guard cells of the ch1-1 mutants accumulated significantly less GSH than the WT plants. The guard cells of the ch1-1 mutants also showed higher sensitivity to ABA than the WT plants. The CDNB treatment increased but the GSHmee treatment decreased the ABA sensitivity of the guard cells without affecting ABA-induced ROS production. Dark and light treatments altered the GSH content and stomatal aperture of the guard cells of ch1-1 and WT plants, irrespective of CDNB and GSHmee. The ch1-1 mutant contained fewer guard cells and displayed poor growth, late flowering and stumpy weight loss compared with the WT plants. This study suggests that defective LHCs reduced the GSH content in the guard cells and increased sensitivity to ABA, resulting in stomatal closure. PMID:26970687

  10. The secreted protein acidic and rich in cysteine is a critical mediator of cell death program induced by WIN/TRAIL combined treatment in osteosarcoma cells.

    PubMed

    Notaro, Antonietta; Sabella, Selenia; Pellerito, Ornella; Vento, Renza; Calvaruso, Giuseppe; Giuliano, Michela

    2016-03-01

    Secreted protein acidic and rich in cysteine (SPARC) is a multi-functional protein which modulates cell-cell and cell-matrix interactions. In cancer cells, SPARC behaves as a tumor promoter in a number of tumors, but it can also act as a tumor suppressor factor. Our previous results showed that the synthetic cannabinoid WIN55,212-2 (WIN), a potent cannabinoid receptor agonist, is able to sensitize osteosarcoma MG63 cells to TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis which is accompanied with endoplasmic reticulum (ER)-stress induction and the increase in autophagic markers. In the present investigation, we studied the role of SPARC in WIN/TRAIL-induced apoptosis demonstrating that WIN increased the level of SPARC protein and mRNA in a time-dependent manner. This event was functional to WIN/TRAIL-dependent apoptosis as demonstrated by RNA interfering analysis which indicated that SPARC-silenced cells were less sensitive to cytotoxic effects induced by the combined treatment. Our experiments also demonstrate that SPARC interacts with caspase-8 thus probably favoring its translocation to plasma membrane and the activation of extrinsic apoptotic pathway. In conclusion, to the best of our knowledge, our results are the first to show that WIN-dependent increase in the level of SPARC plays a critical role in sensitizing osteosarcoma cells to TRAIL action. PMID:26698404

  11. Curcumin inhibits intracellular fatty acid synthase and induces apoptosis in human breast cancer MDA-MB-231 cells.

    PubMed

    Fan, Huijin; Liang, Yan; Jiang, Bing; Li, Xiabing; Xun, Hang; Sun, Jia; He, Wei; Lau, Hay Tong; Ma, Xiaofeng

    2016-05-01

    High levels of fatty acid synthase (FAS) expression have been found in many tumors, including prostate, breast, and ovarian cancers, and inhibition of FAS has been reported to obstruct tumor growth in vitro and in vivo. Curcumin is one of the major active ingredients of Curcuma longa, which has been proven to inhibit the growth of cancer cells. In the present study, we investigated the potential activity of curcumin as a FAS inhibitor for chemoprevention of breast cancer. As a result, curcumin induced human breast cancer MDA-MB-231 cell apoptosis with the half-inhibitory concentration value of 3.63 ± 0.26 µg/ml, and blocked FAS activity, expression and mRNA level in a dose-dependent manner. Curcumin also regulated B-cell lymphoma 2 (Bcl-2), Bax and p-Akt protein expression in MDA-MB-231 cells. Moreover, FAS knockdown showed similar effect as curcumin. All these results suggested that curcumin may induce cell apoptosis via inhibiting FAS. PMID:26985864

  12. Acid-sensing ion channel 1a is involved in retinal ganglion cell death induced by hypoxia

    PubMed Central

    Tan, Jian; Xu, Yipin; Wang, Hao; Sheng, Minjie; Wang, Fang

    2011-01-01

    Purpose Loss of retinal ganglion cells (RGCs) during retinal ischemia is the potentially blinding mechanism that underlies several sight-threatening disorders. Fluctuations in extracellular pH are associated with such pathological conditions. It has been demonstrated that the retina is a functionally distinct region of central neurons that are known to contain acid-sensing ion channels (ASICs), which are depolarizing conductance channels directly activated by protons. This study was conducted to determine whether ASIC1a channels in RGCs are essential for ischemia-induced cell death. Methods Expression of ASIC1a channels was detected in primary cultures of rat RGCs and in retinal sections. The patch-clamp technique in the conventional whole-cell configuration was used to examine the currents evoked by acid in the cultured RGCs. Intracellular Ca2+ ([Ca2+]i) elevation was detected by Ca2+ imaging. Furthermore, hypoxia-induced cell death in RGC cultures was measured by methyl thiazolyl tetrazolium assay. Results RGCs expressed a high density of ASIC1a channels. The expression and function of ASIC1a channels were upregulated after hypoxia in cultured RGCs. Ratiometric Ca2+ imaging showed that RGCs responding to a drop in pH presented an increase in the concentration of (Ca2+)i. Acute blockade of ASIC1a channels with the specific inhibitor amiloride or psalmotoxin 1 reduced RGC death in vitro. Conclusions Based on these novel findings, we conclude that ASIC1a plays a role in RGC death induced by hypoxia. Therefore, neuroprotective strategies in glaucoma could include tools to improve the ability of these neurons to survive the cytotoxic consequences of ASIC1a activation. PMID:22194656

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

    PubMed

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

    2015-01-01

    Alpinia oxyphylla MIQ (Alpinate Oxyphyllae Fructus, AOF) is an important traditional Chinese medicinal herb whose fruits is widely used to prepare tonics and is used as an aphrodisiac, anti salivary, anti diuretic and nerve-protective agent. Protocatechuic acid (PCA), a simple phenolic compound was isolated from the kernels of AOF. This study investigated the role of PCA in promoting neural regeneration and the underlying molecular mechanisms. Nerve regeneration is a complex physiological response that takes place after injury. Schwann cells play a crucial role in the endogenous repair of peripheral nerves due to their ability to proliferate and migrate. The role of PCA in Schwann cell migration was determined by assessing the induced migration potential of RSC96 Schwann cells. PCA induced changes in the expression of proteins of three MAPK pathways, as determined using Western blot analysis. In order to determine the roles of MAPK (ERK1/2, JNK, and p38) pathways in PCA-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production, the expression of several MAPK-associated proteins was analyzed after siRNA-mediated inhibition assays. Treatment with PCA-induced ERK1/2, JNK, and p38 phosphorylation that activated the downstream expression of PAs and MMPs. PCA-stimulated ERK1/2, JNK and p38 phosphorylation was attenuated by individual pretreatment with siRNAs or MAPK inhibitors (U0126, SP600125, and SB203580), resulting in the inhibition of migration and the uPA-related signal pathway. Taken together, our data suggest that PCA extract regulate the MAPK (ERK1/2, JNK, and p38)/PA (uPA, tPA)/MMP (MMP2, MMP9) mediated regeneration and migration signaling pathways in Schwann cells. Therefore, PCA plays a major role in Schwann cell migration and the regeneration of damaged peripheral nerve. PMID:26119854

  14. Valproic acid induces autophagy by suppressing the Akt/mTOR pathway in human prostate cancer cells

    PubMed Central

    Xia, Qinghua; Zheng, Yi; Jiang, Wei; Huang, Zhongxian; Wang, Muwen; Rodriguez, Ronald; Jin, Xunbo

    2016-01-01

    Previous studies have demonstrated that the chronic administration of valproic acid (VPA) suppresses angiogenesis in vivo; however, the mechanisms implicated in VPA-induced autophagy remain unclear. The current study aimed to assess VPA-induced autophagy in three prostate cancer cell lines (PC3, DU145 and LNCaP), in addition to analyzing the Akt/mammalian target of rapamycin (mTOR) signal pathway. Prostate cancer cell lines were cultured with various doses of VPA. Cell cycle was analyzed using flow cytometry, and autophagy markers [1A/1B-light chain 3 (LC3)-II and Beclin-1] were examined using transmission electron microscopy, fluorescent microscopy and western blotting. Activation of the Akt/mTOR signal pathway was also assessed by western blotting. The results demonstrated that VPA induced autophagosomes and suppressed the Akt/mTOR signal pathway. This was confirmed by detection of increased LC3-II and Beclin-1 in VPA-treated cells compared with untreated controls. Phosphorylated forms of Akt (PC3, P=0.048; DU145, P=0.045; LNCaP, P=0.039) and mTOR (PC3, P=0.012; DU145, P=0.41; LNCaP, P=0.35) were significantly reduced following VPA treatment. These results suggest that VPA may function as a histone deacetylase inhibitor, suppressing the growth of prostate cancer cells by modulating autophagy pathways, including inhibition of the Akt/mTOR pathway. Further experiments are required to determine the significance of all involved pathways regarding VPA-induced growth inhibition. PMID:27588130

  15. The effect of ferulic acid ethyl ester on leptin-induced proliferation and migration of aortic smooth muscle cells.

    PubMed

    Tsai, Yung-Chieh; Lee, Yen-Mei; Hsu, Chih-Hsiung; Leu, Sy-Ying; Chiang, Hsiao-Yen; Yen, Mao-Hsiung; Cheng, Pao-Yun

    2015-01-01

    Leptin is a peptide hormone, which has a central role in the regulation of body weight; it also exerts many potentially atherogenic effects. Ferulic acid ethyl ester (FAEE) has been approved for antioxidant properties. The aim of this study was to investigate whether FAEE can inhibit the atherogenic effects of leptin and the possible molecular mechanism of its action. Both of cell proliferation and migration were measured when the aortic smooth muscle cell (A10 cell) treated with leptin and/or FAEE. Phosphorylated p44/42MAPK, cell cycle-regulatory protein (for example, cyclin D1, p21, p27), β-catenin and matrix metalloproteinase-9 (MMP-9) proteins levels were also measured. Results demonstrated that leptin (10, 100 ng ml(-1)) significantly increased the proliferation of cells and the phosphorylation of p44/42MAPK in A10 cells. The proliferative effect of leptin was significantly reduced by the pretreatment of U0126 (0.5 μM), a MEK inhibitor, in A10 cells. Meanwhile, leptin significantly increased the protein expression of cyclin D1, p21, β-catenin and decreased the expression of p27 in A10 cells. In addition, leptin (10 ng ml(-1)) significantly increased the migration of A10 cells and the expression of MMP-9 protein. Above effects of leptin were significantly reduced by the pretreatment of FAEE (1 and 10 μM) in A10 cells. In conclusion, FAEE exerts multiple effects on leptin-induced cell proliferation and migration, including the inhibition of p44/42MAPK phosphorylation, cell cycle-regulatory proteins and MMP-9, thereby suggesting that FAEE may be a possible therapeutic approach to the inhibition of obese vascular disease. PMID:26315599

  16. Agmatine protects Müller cells from high-concentration glucose-induced cell damage via N-methyl-D-aspartic acid receptor inhibition.

    PubMed

    Han, Ning; Yu, Li; Song, Zhidu; Luo, Lifu; Wu, Yazhen

    2015-07-01

    Neural injury is associated with the development of diabetic retinopathy. Müller cells provide structural and metabolic support for retinal neurons. High glucose concentrations are known to induce Müller cell activity. Agmatine is an endogenous polyamine, which is enzymatically formed in the mammalian brain and has exhibited neuroprotective effects in a number of experimental models. The aims of the present study were to investigate whether agmatine protects Müller cells from glucose-induced damage and to explore the mechanisms underlying this process. Lactate dehydrogenase activity and tumor necrosis factor-α mRNA expression were significantly reduced in Müller cells exposed to a high glucose concentration, following agmatine treatment, compared with cells not treated with agmatine. In addition, agmatine treatment inhibited glucose-induced Müller cell apoptosis, which was associated with the regulation of Bax and Bcl-2 expression. Agmatine treatment suppressed glucose-induced phosphorylation of mitogen-activated protein kinase (MAPK) protein in Müller cells. The present study demonstrated that the protective effects of agmatine on Müller cells were inhibited by N-methyl-D-aspartic acid (NMDA). The results of the present study suggested that agmatine treatment protects Müller cells from high-concentration glucose-induced cell damage. The underlying mechanisms may relate to the anti-inflammatory and antiapoptotic effects of agmatine, as well as to the inhibition of the MAPK pathway, via NMDA receptor suppression. Agmatine may be of use in the development of novel therapeutic approaches for patients with diabetic retinopathy. PMID:25816073

  17. Renoprotective effect of DPP-4 inhibitors against free fatty acid-bound albumin-induced renal proximal tubular cell injury.

    PubMed

    Tanaka, Yuki; Kume, Shinji; Chin-Kanasaki, Masami; Araki, Hisazumi; Araki, Shin-ichi; Ugi, Satoshi; Sugaya, Takeshi; Uzu, Takashi; Maegawa, Hiroshi

    2016-02-12

    Dipeptidyl peptidase (DPP)-4 inhibitors, a new class of antidiabetic agent, have recently been suggested to exert pleiotropic effects beyond glucose lowering. Renal prognosis in patients with diabetic nephropathy depends on the severity of tubulointerstitial injury induced by massive proteinuria. We thus examined the renoprotective effect of DPP-4 inhibitors on inflammation in cultured mouse proximal tubular cells stimulated with free fatty acid (FFA)-bound albumin. Linagliptin and higher concentrations of sitagliptin, vildagliptin, and alogliptin all inhibited FFA-bound albumin-induced increases in mRNA expression of MCP-1 in cultured mouse proximal tubular cells. Furthermore, linagliptin significantly inhibited tubulointerstitial injury induced by peritoneal injection of FFA-bound albumin, such as inflammation, fibrosis, and apoptosis, in mice without altering systemic characteristics including body weight, fasting blood glucose, and food intake. These results indicate that DPP-4 inhibitors pleiotropically exert a direct renoprotective effect, and may serve as an additional therapeutic strategy to protect proximal tubular cells against proteinuria in patients with diabetic nephropathy. PMID:26802469

  18. Inhibition of hypoxia inducible factors combined with all-trans retinoic acid treatment enhances glial transdifferentiation of neuroblastoma cells

    PubMed Central

    Cimmino, Flora; Pezone, Lucia; Avitabile, Marianna; Acierno, Giovanni; Andolfo, Immacolata; Capasso, Mario; Iolascon, Achille

    2015-01-01

    Neuroblastoma (NBL) is a heterogeneous tumor characterized by a wide range of clinical manifestations. A high tumor cell differentiation grade correlates to a favorable stage and positive outcome. Expression of the hypoxia inducible factors HIF1-α (HIF1A gene) and HIF2-α (EPAS1 gene) and/or hypoxia-regulated pathways has been shown to promote the undifferentiated phenotype of NBL cells. Our hypothesis is that HIF1A and EPAS1 expression represent one of the mechanisms responsible for the lack of responsiveness of NBL to differentiation therapy. Clinically, high levels of HIF1A and EPAS1 expression were associated with inferior survival in two NBL microarray datasets, and patient subgroups with lower expression of HIF1A and EPAS1 showed significant enrichment of pathways related to neuronal differentiation. In NBL cell lines, the combination of all-trans retinoic acid (ATRA) with HIF1A or EPAS1 silencing led to an acquired glial-cell phenotype and enhanced expression of glial-cell differentiation markers. Furthermore, HIF1A or EPAS1 silencing might promote cell senescence independent of ATRA treatment. Taken together, our data suggest that HIF inhibition coupled with ATRA treatment promotes differentiation into a more benign phenotype and cell senescence in vitro. These findings open the way for additional lines of attack in the treatment of NBL minimal residue disease. PMID:26057707

  19. Inhibition of hypoxia inducible factors combined with all-trans retinoic acid treatment enhances glial transdifferentiation of neuroblastoma cells.

    PubMed

    Cimmino, Flora; Pezone, Lucia; Avitabile, Marianna; Acierno, Giovanni; Andolfo, Immacolata; Capasso, Mario; Iolascon, Achille

    2015-01-01

    Neuroblastoma (NBL) is a heterogeneous tumor characterized by a wide range of clinical manifestations. A high tumor cell differentiation grade correlates to a favorable stage and positive outcome. Expression of the hypoxia inducible factors HIF1-α (HIF1A gene) and HIF2-α (EPAS1 gene) and/or hypoxia-regulated pathways has been shown to promote the undifferentiated phenotype of NBL cells. Our hypothesis is that HIF1A and EPAS1 expression represent one of the mechanisms responsible for the lack of responsiveness of NBL to differentiation therapy. Clinically, high levels of HIF1A and EPAS1 expression were associated with inferior survival in two NBL microarray datasets, and patient subgroups with lower expression of HIF1A and EPAS1 showed significant enrichment of pathways related to neuronal differentiation. In NBL cell lines, the combination of all-trans retinoic acid (ATRA) with HIF1A or EPAS1 silencing led to an acquired glial-cell phenotype and enhanced expression of glial-cell differentiation markers. Furthermore, HIF1A or EPAS1 silencing might promote cell senescence independent of ATRA treatment. Taken together, our data suggest that HIF inhibition coupled with ATRA treatment promotes differentiation into a more benign phenotype and cell senescence in vitro. These findings open the way for additional lines of attack in the treatment of NBL minimal residue disease. PMID:26057707

  20. Derivatives of Dictyostelium differentiation-inducing factors inhibit lysophosphatidic acid-stimulated migration of murine osteosarcoma LM8 cells.

    PubMed

    Kubohara, Yuzuru; Komachi, Mayumi; Homma, Yoshimi; Kikuchi, Haruhisa; Oshima, Yoshiteru

    2015-08-01

    Osteosarcoma is a common metastatic bone cancer that predominantly develops in children and adolescents. Metastatic osteosarcoma remains associated with a poor prognosis; therefore, more effective anti-metastatic drugs are needed. Differentiation-inducing factor-1 (DIF-1), -2, and -3 are novel lead anti-tumor agents that were originally isolated from the cellular slime mold Dictyostelium discoideum. Here we investigated the effects of a panel of DIF derivatives on lysophosphatidic acid (LPA)-induced migration of mouse osteosarcoma LM8 cells by using a Boyden chamber assay. Some DIF derivatives such as Br-DIF-1, DIF-3(+2), and Bu-DIF-3 (5-20 μM) dose-dependently suppressed LPA-induced cell migration with associated IC50 values of 5.5, 4.6, and 4.2 μM, respectively. On the other hand, the IC50 values of Br-DIF-1, DIF-3(+2), and Bu-DIF-3 versus cell proliferation were 18.5, 7.2, and 2.0 μM, respectively, in LM8 cells, and >20, 14.8, and 4.3 μM, respectively, in mouse 3T3-L1 fibroblasts (non-transformed). Together, our results demonstrate that Br-DIF-1 in particular may be a valuable tool for the analysis of cancer cell migration, and that DIF derivatives such as DIF-3(+2) and Bu-DIF-3 are promising lead anti-tumor agents for the development of therapies that suppress osteosarcoma cell proliferation, migration, and metastasis. PMID:26056940

  1. Cis-vaccenic acid induces differentiation and up-regulates gamma globin synthesis in K562, JK1 and transgenic mice erythroid progenitor stem cells.

    PubMed

    Aimola, Idowu A; Inuwa, Hajiya M; Nok, Andrew J; Mamman, Aisha I; Bieker, James J

    2016-04-01

    Gamma globin induction remains a promising pharmacological therapeutic treatment mode for sickle cell anemia and beta thalassemia, however Hydroxyurea remains the only FDA approved drug which works via this mechanism. In this regard, we assayed the γ-globin inducing capacity of Cis-vaccenic acid (CVA). CVA induced differentiation of K562, JK1 and transgenic mice primary bone marrow hematopoietic progenitor stem cells. CVA also significantly up-regulated γ-globin gene expression in JK-1 and transgenic mice bone marrow erythroid progenitor stem cells (TMbmEPSCs) but not K562 cells without altering cell viability. Increased γ-globin expression was accompanied by KLF1 suppression in CVA induced JK-1 cells. Erythropoietin induced differentiation of JK-1 cells 24h before CVA induction did not significantly alter CVA induced differentiation and γ-globin expression in JK-1 cells. Inhibition of JK-1 and Transgenic mice bone marrow erythroid progenitor stem cells Fatty acid elongase 5 (Elovl5) and Δ(9) desaturase suppressed the γ-globin inductive effects of CVA. CVA treatment failed to rescue γ-globin expression in Elovl5 and Δ(9)-desaturase inhibited cells 48 h post inhibition in JK-1 cells. The data suggests that CVA directly modulates differentiation of JK-1 and TMbmEPSCs, and indirectly modulates γ-globin gene expression in these cells. Our findings provide important clues for further evaluations of CVA as a potential fetal hemoglobin therapeutic inducer. PMID:26879870

  2. Propionic acid secreted from propionibacteria induces NKG2D ligand expression on human-activated T lymphocytes and cancer cells.

    PubMed

    Andresen, Lars; Hansen, Karen Aagaard; Jensen, Helle; Pedersen, Stine Falsig; Stougaard, Peter; Hansen, Helle Rüsz; Jurlander, Jesper; Skov, Søren

    2009-07-15

    We found that propionic acid secreted from propionibacteria induces expression of the NKG2D ligands MICA/B on activated T lymphocytes and different cancer cells, without affecting MICA/B expression on resting peripheral blood cells. Growth supernatant from propionibacteria or propionate alone could directly stimulate functional MICA/B surface expression and MICA promoter activity by a mechanism dependent on intracellular calcium. Deletion and point mutations further demonstrated that a GC-box motif around -110 from the MICA transcription start site is essential for propionate-mediated MICA promoter activity. Other short-chain fatty acids such as lactate, acetate, and butyrate could also induce MICA/B expression. We observed a striking difference in the molecular signaling pathways that regulate MICA/B. A functional glycolytic pathway was essential for MICA/B expression after exposure to propionate and CMV. In contrast, compounds with histone deacetylase-inhibitory activity such as butyrate and FR901228 stimulated MICA/B expression through a pathway that was not affected by inhibition of glycolysis, clearly suggesting that MICA/B is regulated through different molecular mechanisms. We propose that propionate, produced either by bacteria or during cellular metabolism, has significant immunoregulatory function and may be cancer prophylactic. PMID:19553547

  3. Pomegranate seed oil: Effect on 3-nitropropionic acid-induced neurotoxicity in PC12 cells and elucidation of unsaturated fatty acids composition.

    PubMed

    Al-Sabahi, Bushra N; Fatope, Majek O; Essa, Musthafa Mohamed; Subash, Selvaraju; Al-Busafi, Saleh N; Al-Kusaibi, Fatma S N; Manivasagam, Thamilarasan

    2014-09-19

    Background Seed oils are used as cosmetics or topical treatment for wounds, allergy, dandruff, and other purposes. Natural antioxidants from plants were recently reported to delay the onset or progress of various neurodegenerative conditions. Over one thousand cultivars of Punica granatum (Punicaceae) are known and some are traditionally used to treat various ailments. Aim The effect of pomegranate oil on 3-nitropropionic acid- (3-NP) induced cytotoxicity in rat pheochromocytoma (PC12) neuronal cells was analyzed in this study. Furthermore, the analysis of unsaturated fatty acid composition of the seed oil of pomegranate by gas chromatography-electron impact mass spectrometry (GC-MS) was done. Results GC-MS study showed the presence of 6,9-octadecadiynoic acid (C18:2(6,9)) as a major component (60%) as 4,4-dimethyloxazoline derivative. The total extractable oil with light petroleum ether by Soxhlet from the dry seed of P. granatum was 4-6%. The oil analyzed for 48.90 ± 1.50 mg gallic acid equivalents/g of oil, and demonstrated radical-scavenging-linked antioxidant activities in various in vitro assays like the DPPH (2,2-diphenyl-l-picrylhydrazyl, % IP = 35.2 ± 0.9%), ABTS (2,2'-azino-bis-3-ethylene benzothiozoline-6-sulfonic acid, % IP 2.2 ± 0.1%), and β-carotene bleaching assay (% IP = 26 ± 3%), respectively, which could be due the possible role of one methylene interrupted diynoic acid system for its radical-scavenging/antioxidant properties of oil. The oil also reduced lipid peroxidation, suppressed reactive oxygen species, extracellular nitric oxide, lactate/pyruvate ratio, and lactase dehydrogenase generated by 3-NP- (100 mM) induced neurotoxicity in PC12 cells, and enhanced the levels of enzymatic and non-enzymatic antioxidants at 40 μg of gallic acid equivalents. Conclusion The protective effect of pomegranate seed oil might be due to the ability of an oil to neutralize ROS or enhance the expression of antioxidant gene. PMID:25238165

  4. Carnosic acid induces apoptosis associated with mitochondrial dysfunction and Akt inactivation in HepG2 cells.

    PubMed

    Xiang, Qisen; Ma, Yunfang; Dong, Jilin; Shen, Ruiling

    2015-02-01

    Carnosic acid (CA), a phenolic diterpene isolated from rosemary, shows potential benefits in health promotion and disease prevention. In the present study, the cytotoxic and apoptotic-inducing effects of CA on human hepatocellular carcinoma HepG2 cells were investigated. The MTT assay results indicated that CA decreased cell viability in HepG2 cells in a dose-dependent manner. Treatment with CA caused a rapid Caspase-3 activation and subsequently proteolytic cleavage of poly (ADP-ribose) polymerase (PARP), both of which were markers of cells undergoing apoptosis. CA also dissipated mitochondrial membrane potential and decreased the ratio of Bcl-2/Bax protein, which mediated cytosolic translocation of cytochrome c from the mitochondria. Furthermore, CA reduced the phosphorylation of Akt, which was partially inhibited by insulin, an activator of phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway. In conclusion, our data suggest that the mitochondrial dysfunction and deactivation of Akt may contribute to the apoptosis-inducing effects of CA. PMID:25265205

  5. N-3 polyunsaturated fatty acids inhibit IFN-γ-induced IL-18 binding protein production by prostate cancer cells.

    PubMed

    Wang, Xiaofeng; Breeze, Andrew; Kulka, Marianna

    2015-02-01

    Prostate cancer cells can produce IL-18 binding protein (IL-18BP) in response to interferon-γ (IFN-γ), which may function to neutralize IL-18, an anti-tumor factor formerly known as IFN-γ inducing factor. The consumption of n-3 polyunsaturated fatty acids (PUFAs) has been associated with a lower risk of certain types of cancer including prostate cancer, although the precise mechanisms of this effect are poorly understood. We hypothesized that n-3 PUFAs could modify IL-18BP production by prostate cancer cells by altering IFN-γ receptor-mediated signal transduction. Here, we demonstrate that n-3 PUFA treatment significantly reduced IFN-γ-induced IL-18BP production by DU-145 and PC-3 prostate cancer cells by inhibiting IL-18BP mRNA expression and was associated with a reduction in IFN-γ receptor expression. Furthermore, IFN-γ-induced phosphorylation of Janus kinase 1 (JAK1), signal transducers and activators of transcription 1 (STAT1), extracellular signal-regulated kinases 1/2 (ERK1/2), and P38 were suppressed by n-3 PUFA treatment. By contrast, n-6 PUFA had no effect on IFN-γ receptor expression, but decreased IFN-γ-induced IL-18BP production and IFN-γ stimulation of JAK1, STAT1, ERK1/2, and JNK phosphorylation. These data indicate that both n-3 and n-6 PUFAs may be beneficial in prostate cancer by altering IFN-γ signaling, thus inhibiting IL-18BP production and thereby rendering prostate cancer cells more sensitive to IL-18-mediated immune responses. PMID:25351720

  6. Abietic acid inhibits UVB-induced MMP-1 expression in human dermal fibroblast cells through PPARα/γ dual activation.

    PubMed

    Jeon, Youngsic; Jung, Yujung; Youm, Jong-Kyung; Kang, Ki Sung; Kim, Yong Kee; Kim, Su-Nam

    2015-02-01

    Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors and consist of three isotypes: PPARα, PPARβ/δ and PPARγ. PPARs are expressed in various cell types in the skin, including keratinocytes, fibroblasts and infiltrating immune cells. Thus, these receptors are highly studied in dermato-endocrine research, and their ligands are targets for the treatment of various skin disorders, such as photoageing and chronological ageing of skin. Intensive studies have revealed that PPARα/γ functions in photoageing and age-related inflammation by regulating matrix metalloproteinases (MMPs) via nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1). However, the detailed mechanism of PPARα/γ's role in photoageing has not yet been elucidated. In this study, we confirmed that abietic acid (AA) is a PPARα/γ dual ligand and significantly decreased UVB-induced MMP-1 expression by downregulating UVB-induced MAPK signalling and downstream transcription factors, subsequently reducing IκBα degradation and blocking NF-κB p65 nuclear translocation in Hs68 human dermal fibroblast cells. Treatment of cells with AA and GW6471 or bisphenol A diglycidyl ether (BADGE), PPARα or PPARγ antagonists, respectively, reversed the effect on UVB-induced MMP-1 expression and inflammatory signalling pathway activation. Taken together, our data suggest that AA acts as a PPARα/γ dual activator to inhibit UVB-induced MMP-1 expression and age-related inflammation by suppressing NF-κB and the MAPK/AP-1 pathway and can be a useful agent for improving skin photoageing. PMID:25496486

  7. The pentacyclic triterpenoid, plectranthoic acid, a novel activator of AMPK induces apoptotic death in prostate cancer cells.

    PubMed

    Akhtar, Nosheen; Syed, Deeba N; Khan, Mohammad Imran; Adhami, Vaqar M; Mirza, Bushra; Mukhtar, Hasan

    2016-01-26

    Epidemiologic studies indicated that diabetics treated with metformin had a lower incidence of cancer than those taking other anti-diabetes drugs. This led to a surge in the efforts for identification of safer and more effective metformin mimetic compounds. The plant Ficus microcarpa is widely used for the treatment of type 2 diabetes in traditional medicine in South Asia. We obtained extracts from this plant and identified a small molecule, plectranthoic acid (PA), with potent 5'AMP-activated kinase (AMPK) activating properties far superior than metformin. AMPK is the central hub of metabolic regulation and a well-studied therapeutic target for metabolic syndrome, type-2 diabetes and cancer. We observed that treatment of prostate cancer (PCa) cells with PA inhibited proliferation and induced G0/G1 phase cell cycle arrest that was associated with up-regulation of cyclin kinase inhibitors p21/CIP1 and p27/KIP1. PA treatment suppressed mTOR/S6K signaling and induced apoptosis in PCa cells in an AMPK-dependent manner. Interestingly, PA-induced autophagy in PCa cells was found to be independent of AMPK activation. Combination studies of PA and metformin demonstrated that metformin had an inhibitory effect on PA-induced AMPK activation and suppressed PA-mediated apoptosis. Given the anti-proliferative role of PA in cancer and its potent anti-hyperglycemic activity, we suggest that PA should be explored further as a novel activator of AMPK for its ultimate use for the prevention of cancers and treatment of type 2 diabetes. PMID:26683363

  8. Achievements and perspectives in yeast acetic acid-induced programmed cell death pathways.

    PubMed

    Guaragnella, Nicoletta; Antonacci, Lucia; Passarella, Salvatore; Marra, Ersilia; Giannattasio, Sergio

    2011-10-01

    The use of non-mammalian model organisms, including yeast Saccharomyces cerevisiae, can provide new insights into eukaryotic PCD (programmed cell death) pathways. In the present paper, we report recent achievements in the elucidation of the events leading to PCD that occur as a response to yeast treatment with AA (acetic acid). In particular, ROS (reactive oxygen species) generation, cyt c (cytochrome c) release and mitochondrial function and proteolytic activity will be dealt with as they vary along the AA-PCD time course by using both wild-type and mutant yeast cells. Two AA-PCD pathways are described sharing common features, but distinct from one another with respect to the role of ROS and mitochondria, the former in which YCA1 acts upstream of cyt c release and caspase-like activation in a ROS-dependent manner and the latter in which cyt c release does not occur, but caspase-like activity increases, in a ROS-independent manner. PMID:21936848

  9. Enterococcus faecalis lipoteichoic acid suppresses Aggregatibacter actinomycetemcomitans lipopolysaccharide-induced IL-8 expression in human periodontal ligament cells.

    PubMed

    Im, Jintaek; Baik, Jung Eun; Kim, Kyoung Whun; Kang, Seok-Seong; Jeon, Jun Ho; Park, Ok-Jin; Kim, Hyun Young; Kum, Kee-Yeon; Yun, Cheol-Heui; Han, Seung Hyun

    2015-08-01

    Periodontitis is caused by multi-bacterial infection and Aggregatibacter actinomycetemcomitans and Enterococcus faecalis are closely associated with inflammatory periodontal diseases. Although lipopolysaccharide (LPS) of A. actinomycetemcomitans (Aa.LPS) and lipoteichoic acid of E. faecalis (Ef.LTA) are considered to be major virulence factors evoking inflammatory responses, their combinatorial effect on the induction of chemokines has not been investigated. In this study, we investigated the interaction between Aa.LPS and Ef.LTA on IL-8 expression in human periodontal ligament (PDL) cells. Aa.LPS, but not Ef.LTA, substantially induced IL-8 expression at the protein and mRNA levels. Interestingly, Ef.LTA suppressed Aa.LPS-induced IL-8 expression without affecting the binding of Aa.LPS to Toll-like receptor (TLR) 4. Ef.LTA reduced Aa.LPS-induced phosphorylation of mitogen-activated protein kinases, including ERK, JNK and p38 kinase. Furthermore, Ef.LTA inhibited the Aa.LPS-induced transcriptional activities of the activating protein 1, CCAAT/enhancer-binding protein and nuclear factor-kappa B transcription factors, all of which are known to regulate IL-8 gene expression. Ef.LTA augmented the expression of IL-1 receptor-associated kinase-M (IRAK-M), a negative regulator of TLR intracellular signaling pathways, in the presence of Aa.LPS at both the mRNA and protein levels. Small interfering RNA silencing IRAK-M reversed the attenuation of Aa.LPS-induced IL-8 expression by Ef.LTA. Collectively, these results suggest that Ef.LTA down-regulates Aa.LPS-induced IL-8 expression in human PDL cells through up-regulation of the negative regulator IRAK-M. PMID:25840438

  10. Dihydroceramide-desaturase-1-mediated caspase 9 activation through ceramide plays a pivotal role in palmitic acid-induced HepG2 cell apoptosis.

    PubMed

    Zhu, Qun; Yang, Jianjun; Zhu, Rongping; Jiang, Xin; Li, Wanlian; He, Songqing; Jin, Junfei

    2016-09-01

    In this study, results showed that the inhibition of PA-induced HepG2 cell growth takes place in a time- and concentration-dependent manner, that activation of caspase 9 is necessary for PA-induced HepG2 cell apoptosis, that dihydroceramide desaturase 1 (DES1) plays a key role in PA-mediated caspase 9 and caspase 3 activation, and that palmitoleic acid (POA), an omega-7 monounsaturated fatty acid, reverses PA-induced apoptosis through DES1 → Ceramide → Caspase 9 → Caspase 3 signaling. PMID:27364952

  11. Ellagic acid inhibits PDGF-BB-induced vascular smooth muscle cell proliferation and prevents atheroma formation in streptozotocin-induced diabetic rats.

    PubMed

    Rani, Uma P; Kesavan, Rushendhiran; Ganugula, Raghu; Avaneesh, T; Kumar, Uday P; Reddy, G Bhanuprakash; Dixit, Madhulika

    2013-11-01

    Plant-derived polyphenolic compounds have beneficial health effects. In the present study, we determined the ability of ellagic acid (EA) to prevent platelet-derived growth factor-BB (PDGF-BB)-induced proliferation of primary cultures of rat aortic smooth muscle cells (RASMCs). We also determined the ability of EA to prevent atherosclerosis in streptozotocin-induced diabetic rats. Proliferation of cells was measured via Alamar Blue assay and through propidium iodide-based cell cycle analysis in flow cytometer. Reactive oxygen species (ROS) were measured via 2',7'-dichlorofluorescin diacetate and Amplex red methods. Expression of proliferation markers and activation of kinases were assessed by immunoblot analysis. Cotreatment of primary cultures of RASMCs with 25 μmol/L of EA significantly reduced PDGF-BB (20 ng/ml)-induced proliferation by blocking S-phase entry. EA effectively blocked PDGF receptor-β (PDGFR-β) tyrosine phosphorylation, generation of intracellular ROS and downstream activation of extracellular signal-regulated kinase 1/2. It also blocked PDGF-BB-induced expression of cyclin D1. Computational molecular docking of EA with the PDGFR-β-PDGF-BB complex revealed two putative inhibitor binding sites which showed similar binding energies with the known PDGFR-β inhibitor AG1295. In diabetic rats, supplementation of diet with 2% EA significantly blocked diabetes-induced medial thickness, and lipid and collagen deposition in the arch of aorta. These were assessed through haematoxylin and eosin, Oil Red O and Masson's trichome staining, respectively. EA treatment also blocked cyclin D1 expression in medial smooth muscle cells in experimental animals. Thus, EA is effective in reducing atherosclerotic process by blocking proliferation of vascular smooth muscle cells. PMID:23866995

  12. Purified group X secretory phospholipase A(2) induced prominent release of arachidonic acid from human myeloid leukemia cells.

    PubMed

    Hanasaki, K; Ono, T; Saiga, A; Morioka, Y; Ikeda, M; Kawamoto, K; Higashino, K; Nakano, K; Yamada, K; Ishizaki, J; Arita, H

    1999-11-26

    Group X secretory phospholipase A(2) (sPLA(2)-X) possesses several structural features characteristic of both group IB and IIA sPLA(2)s (sPLA(2)-IB and -IIA) and is postulated to be involved in inflammatory responses owing to its restricted expression in the spleen and thymus. Here, we report the purification of human recombinant COOH-terminal His-tagged sPLA(2)-X, the preparation of its antibody, and the purification of native sPLA(2)-X. The affinity-purified sPLA(2)-X protein migrated as various molecular species of 13-18 kDa on SDS-polyacrylamide gels, and N-glycosidase F treatment caused shifts to the 13- and 14-kDa bands. NH(2)-terminal amino acid sequencing analysis revealed that the 13-kDa form is a putative mature sPLA(2)-X and the 14-kDa protein possesses a propeptide of 11 amino acid residues attached at the NH(2) termini of the mature protein. Separation with reverse-phase high performance liquid chromatography revealed that N-linked carbohydrates are not required for the enzymatic activity and pro-sPLA(2)-X has a relatively weak potency compared with the mature protein. The mature sPLA(2)-X induced the release of arachidonic acid from phosphatidylcholine more efficiently than other human sPLA(2) groups (IB, IIA, IID, and V) and elicited a prompt and marked release of arachidonic acid from human monocytic THP-1 cells compared with sPLA(2)-IB and -IIA with concomitant production of prostaglandin E(2). A prominent release of arachidonic acid was also observed in sPLA(2)-X-treated human U937 and HL60 cells. Immunohistochemical analysis of human lung preparations revealed its expression in alveolar epithelial cells. These results indicate that human sPLA(2)-X is a unique N-glycosylated sPLA(2) that releases arachidonic acid from human myeloid leukemia cells more efficiently than sPLA(2)-IB and -IIA. PMID:10567392

  13. Lactic acid bacteria strains exert immunostimulatory effect on H. pylori-induced dendritic cells.

    PubMed

    Wiese, Małgorzata; Eljaszewicz, Andrzej; Helmin-Basa, Anna; Andryszczyk, Marek; Motyl, Ilona; Wieczyńska, Jolanta; Gackowska, Lidia; Kubiszewska, Izabela; Januszewska, Milena; Michałkiewicz, Jacek

    2015-01-01

    The aim of this study was to find out if selected lactic acid bacteria (LAB) strains (antagonistic or nonantagonistic against H. pylori in vitro) would differ in their abilities to modulate the DCs maturation profiles reflected by their phenotype and cytokine expression patterns. Methods. Monocyte-derived DCs maturation was elicited by their direct exposure to the LAB strains of L. rhamnosus 900 or L. paracasei 915 (antagonistic and nonantagonistic to H. pylori, resp.), in the presence or absence of H. pylori strain cagA+. The DCs maturation profile was assessed on the basis of surface markers expression and cytokines production. Results. We observed that the LAB strains and the mixtures of LAB with H. pylori are able to induce mature DCs. At the same time, the L. paracasei 915 leads to high IL-10/IL-12p70 cytokine ratio, in contrast to L. rhamnosus 900. Conclusions. This study showed that the analyzed lactobacilli strains are more potent stimulators of DC maturation than H. pylori. Interestingly from the two chosen LAB strains the antagonistic to H. pylori-L. rhamnosus strain 900 has more proinflammatory and probably antibactericidal properties. PMID:25759836

  14. Glycyrrhizin attenuates kainic Acid-induced neuronal cell death in the mouse hippocampus.

    PubMed

    Luo, Lidan; Jin, Yinchuan; Kim, Il-Doo; Lee, Ja-Kyeong

    2013-06-01

    Glycyrrhizin (GL), a triterpene that is present in the roots and rhizomes of licorice (Glycyrrhiza glabra), has been reported to have anti-inflammatory and anti-viral effects. Recently, we demonstrated that GL produced the neuroprotective effects with the suppression of microglia activation and proinflammatory cytokine induction in the postischemic brain with middle cerebral artery occlusion (MCAO) in rats and improved motor impairment and neurological deficits. In the present study, we investigated whether GL has a beneficial effect in kainic acid (KA)-induced neuronal death model. Intracerebroventricular (i.c.v.) injection of 0.94 nmole (0.2 µg) of KA produced typical neuronal death in both CA1 and CA3 regions of the hippocampus. In contrast, administration of GL (10 mg/kg, i.p.) 30 min before KA administration significantly suppressed the neuronal death, and this protective effect was more stronger at 50 mg/kg. Moreover, the GL-mediated neuroprotection was accompanied with the suppression of gliosis and induction of proinflammatory markers (COX-2, iNOS, and TNF-α). The anti-inflammatory and anti-excitotoxic effects of GL were verified in LPS-treated primary microglial cultures and in NMDA- or KA-treated primary cortical cultures. Together these results suggest that GL confers the neuroprotection through the mechanism of anti-inflammatory and anti-excitotoxic effects in KA-treated brain. PMID:23833559

  15. Folic Acid Represses Hypoxia-Induced Inflammation in THP-1 Cells through Inhibition of the PI3K/Akt/HIF-1α Pathway

    PubMed Central

    Jiang, Xinwei; Hou, Mengjun; Tang, Zhihong; Zhen, Xiaozhou; Liang, Yuming; Ma, Jing

    2016-01-01

    Though hypoxia has been implicated as a cause of inflammation, the underlying mechanism is not well understood. Folic acid has been shown to provide protection against oxidative stress and inflammation in patients with cardiovascular disease and various models approximating insult to tissue via inflammation. It has been reported that hypoxia-induced inflammation is associated with oxidative stress, upregulation of hypoxia-inducible factor 1-alpha (HIF-1α), and production of pro-inflammatory molecules. Whether folic acid protects human monocytic cells (THP-1 cells) against hypoxia-induced damage, however, remains unknown. We used THP-1 cells to establish a hypoxia-induced cellular injury model. Pretreating THP-1 cells with folic acid attenuated hypoxia-induced inflammatory responses, including a decrease in protein and mRNA levels of interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α), coupled with increased levels of IL-10. Folic acid also reduced hypoxia-induced Akt phosphorylation and decreased nuclear accumulation of HIF-1α protein. Both LY294002 (a selective inhibitor of phosphatidyl inositol-3 kinase, PI3K) and KC7F2 (a HIF-1α inhibitor) reduced levels of hypoxia-induced inflammatory cytokines. We also found that insulin (an Akt activator) and dimethyloxallyl glycine (DMOG, a HIF-1α activator) induced over-expression of inflammatory cytokines, which could be blocked by folic acid. Taken together, these findings demonstrate how folic acid attenuates the hypoxia-induced inflammatory responses of THP-1 cells through inhibition of the PI3K/Akt/HIF-1α pathway. PMID:26974319

  16. Kaempferia parviflora extract ameliorates the cognitive impairments and the reduction in cell proliferation induced by valproic acid treatment in rats.

    PubMed

    Welbat, Jariya Umka; Chaisawang, Pornthip; Chaijaroonkhanarak, Wunnee; Prachaney, Parichat; Pannangrong, Wanassanun; Sripanidkulchai, Bungorn; Wigmore, Peter

    2016-07-01

    Kaempferia parviflora is a herbal plant whose rhizomes are used in traditional medicine. Investigations of this plant have shown it to have antidepressant activity and to improve learning and memory in animal models. The aim of the present investigation was to determine whether K. parviflora could protect the brain from the impairments in cognition and hippocampal neurogenesis which are caused by valproic acid (VPA). Male Sprague Dawley rats (180-200g) were given once daily K. parviflora extract (100mg/kg) via oral gavage for 21 days. Rats received twice daily intraperitoneal injections of valproic acid (300mg/kg) from days 8 to 21 of the experiment. Spatial memory was tested using the novel object location (NOL) test five days after the end of treatment. Cell proliferation in the sub granular zone (SGZ) of the dentate gyrus was quantified by immunohistochemistry and levels of doublecortin (DCX) were determined by Western blotting. Co-treatment of VPA and K. parviflora prevented the cognitive decline and reduction in proliferating cells caused by VPA. Furthermore, co-treatment significantly increased DCX protein levels within the hippocampus. These findings demonstrate that K. parviflora is able to prevent the brain from VPA-induced the impairments of spatial memory and proliferating cells within the SGZ. PMID:27142346

  17. Farnesoid X receptor signal is involved in deoxycholic acid-induced intestinal metaplasia of normal human gastric epithelial cells.

    PubMed

    Li, Shu; Chen, Xin; Zhou, Lu; Wang, Bang-Mao

    2015-11-01

    The farnesoid X receptor (FXR) signaling pathway is known to be involved in the metabolism of bile acid, glucose and lipid. In the present study, we demonstrated that 400 µmol/l deoxycholic acid (DCA) stimulation promotes the proliferation of normal human gastric epithelial cells (GES-1). In addition, DCA activated FXR and increased the expression of intestinal metaplasia genes, including caudal-related homeobox transcription factor 2 (Cdx2) and mucin 2 (MUC2). The treatment of FXR agonist GW4064/antagonist guggulsterone (Gug.) significantly increased/decreased the expression levels of FXR, Cdx2 and MUC2 protein in DCA-induced GES-1 cells. GW4064/Gug. also enhanced/reduced the nuclear factor-κB (NF-κB) activity and binding of the Cdx2 promoter region and NF-κB, the most common subunit p50 protein. Taken together, the results indicated that DCA is capable of modulating the expression of Cdx2 and the downstream MUC2 via the nuclear receptor FXR-NF-κB activity in normal gastric epithelial cells. FXR signaling pathway may therefore be involved in the intestinal metaplasia of human gastric mucosa. PMID:26324224

  18. Chebulic acid prevents hepatic fibrosis induced by advanced glycation end-products in LX-2 cell by modulating Nrf2 translocation via ERK pathway.

    PubMed

    Koo, Yun-Chang; Pyo, Min Cheol; Nam, Mi-Hyun; Hong, Chung-Oui; Yang, Sung-Yong; Lee, Kwang-Won

    2016-08-01

    Advanced glycation end-products (AGEs) are formed during normal aging, and at an accelerated rate in metabolic syndrome patients. Nonalcoholic steatohepatitis (NASH) can be caused by the AGEs in plasma, while glyceraldehyde-derived AGEs (glycer-AGEs) are significantly higher in the serum of NASH patients. In this study, we investigated the molecular mechanisms of chebulic acid, isolated from Terminalia chebula Retz., in the inhibition of glycer-AGEs induced production of reactive oxygen species (ROS) and collagen accumulation using the LX-2 cell line. Chebulic acid significantly inhibited the induction of ROS and accumulation of collagen proteins by glycer-AGEs. ERK phosphorylation and total nuclear factor E2-related factor 2 (Nrf2) protein expression were induced by chebulic acid in a dose-dependent manner. Chebulic acid was also found to induce translocation of Nrf2 into the nucleus, which was attenuated by inhibition of ERK phosphorylation through treatment with PD98059. Following translocation of Nrf2, chebulic acid induced the protein expressions of catalytic subunit of γ-glutamylcysteine synthetase and glutathione synthesis. Collagen accumulation was also significantly reduced by chebulic acid treatment. The observed effects of chebulic acid were all inhibited by PD98059 treatment. Taken together, these results suggest that chebulic acid prevents the glycer-AGEs-induced ROS formation of LX-2 cells and collagen accumulation by ERK-phosphorylation-mediated Nrf2 nuclear translocation, which causes upregulation of antioxidant protein production. PMID:27021876

  19. Liver Fatty acid binding protein (L-Fabp) modulates murine stellate cell activation and diet induced nonalcoholic fatty liver disease

    PubMed Central

    Chen, Anping; Tang, Youcai; Davis, Victoria; Hsu, Fong-Fu; Kennedy, Susan M.; Song, Haowei; Turk, John; Brunt, Elizabeth M.; Newberry, Elizabeth P.; Davidson, Nicholas O.

    2013-01-01

    Activation of hepatic stellate cells (HSCs) is crucial to the development of fibrosis in nonalcoholic fatty liver disease. Quiescent HSCs contain lipid droplets (LDs), whose depletion upon activation induces a fibrogenic gene program. Here we show that liver fatty acid-binding protein (L-Fabp), an abundant cytosolic protein that modulates fatty acid (FA) metabolism in enterocytes and hepatocytes also modulates HSC FA utilization and in turn regulates the fibrogenic program. L-Fabp expression decreased 10-fold following HSC activation, concomitant with depletion of LDs. Primary HSCs isolated from L-FABP−/− mice contain fewer LDs than wild type (WT) HSCs, and exhibit upregulated expression of genes involved in HSC activation. Adenoviral L-Fabp transduction inhibited activation of passaged WT HSCs and increased both the expression of prolipogenic genes and also augmented intracellular lipid accumulation, including triglyceride and FA, predominantly palmitate. Freshly isolated HSCs from L-FABP−/− mice correspondingly exhibited decreased palmitate in the free FA pool. To investigate whether L-FABP deletion promotes HSC activation in vivo, we fed L-FABP−/− and WT mice a high fat diet supplemented with trans-fatty acids and fructose (TFF). TFF-fed L-FABP−/− mice exhibited reduced hepatic steatosis along with decreased LD abundance and size compared to WT mice. In addition, TFF-fed L-FABP−/− mice exhibited decreased hepatic fibrosis, with reduced expression of fibrogenic genes, compared to WT mice. Conclusion L-FABP deletion attenuates both diet-induced hepatic steatosis and fibrogenesis, despite the observation that L-Fabp paradoxically promotes FA and LD accumulation and inhibits HSC activation in vitro. These findings highlight the importance of cell-specific modulation of hepatic lipid metabolism in promoting fibrogenesis in nonalcoholic fatty liver disease. PMID:23401290

  20. Kupffer cells suppress perfluorononanoic acid-induced hepatic peroxisome proliferator-activated receptor α expression by releasing cytokines.

    PubMed

    Fang, Xuemei; Zou, Shanshan; Zhao, Yuanyuan; Cui, Ruina; Zhang, Wei; Hu, Jiayue; Dai, Jiayin

    2012-10-01

    Kupffer cells (KCs) have been demonstrated to play a role in the regulation of intra-hepatic lipid metabolism through the synthesis and secretion of biologically active products. The involvement of KCs in the disturbance of lipid metabolism that induced by perfluorononanoic acid (PFNA), a known agonist of the peroxisome proliferator-activated receptor alpha (PPARα), was investigated in this study. Rats were exposed to PFNA or PFNA combined with gadolinium chloride, an inhibitor of KCs, for 14 days. PFNA exposure dose-dependently increased absolute and relative liver weights, induced triglyceride accumulation, up-regulated the expression of both SERBP-1c and PPARα, and stimulated the release of TNFα and IL-1β. Inactivation of KCs markedly lowered TNFα and IL-1β level, enhanced PFNA-induced expression of PPARα and its target genes, and reduced liver triglyceride levels. In vitro, PFNA-induced expression of PPARα in primary cultured hepatocytes was suppressed by recombinant rat TNFα and IL-1β. However, inhibition of the NF-κB pathway prevented this. Transient transfection and promoter analysis further revealed that these two cytokines and NF-κB were coordinately involved in the suppression of PPARα promoter activity. Our data demonstrate that TNFα and IL-1β released from KCs following PFNA exposure can suppress the expression of PPARα via NF-κB pathway, which partially contribute to the evident accumulation of triglycerides in rat liver. PMID:22648072

  1. Inhibitory effect of fangchinoline on excitatory amino acids-induced neurotoxicity in cultured rat cerebellar granule cells.

    PubMed

    Kim, S D; Oh, S K; Kim, H S; Seong, Y H

    2001-04-01

    Glutamate receptors-mediated excitotoxicity is believed to play a role in the pathophysiology of neurodegenerative diseases. The present study was performed to evaluate the inhibitory effect of fangchinoline, a bis-benzylisoquinoline alkaloid, which has a characteristic as a Ca2+ channel blocker, on excitatory amino acids (EAAs)-induced neurotoxicity in cultured rat cerebellar granule neuron. Fangchinoline (1 and 5 microM) inhibited glutamate (1 mM), N-methyl-D-aspartate (NMDA; 1 mM) and kainate (100 microM)-induced neuronal cell death which was measured by trypan blue exclusion test. Fangchinoline (1 and 5 microM) inhibited glutamate release into medium induced by NMDA (1 mM) and kainate (100 microM), which was measured by HPLC. And fangchinoline (5 microM) inhibited glutamate (1 mM)-induced elevation of intracellular calcium concentration. These results suggest that inhibition of Ca2+ influx by fangchinoline may contribute to the beneficial effects on neurodegenerative effect of glutamate in pathophysiological conditions. PMID:11339637

  2. Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell line.

    PubMed

    Dietrich, Fabrícia; Kaiser, Samuel; Rockenbach, Liliana; Figueiró, Fabrício; Bergamin, Letícia Scussel; da Cunha, Fernanda Monte; Morrone, Fernanda Bueno; Ortega, George González; Battastini, Ana Maria Oliveira

    2014-05-01

    Bladder cancer is the second most prevalent malignancy in the genitourinary tract and remains a therapeutic challenge. In the search for new treatments, researchers have attempted to find compounds with low toxicity. With this goal in mind, Uncaria tomentosa is noteworthy because the bark and root of this species are widely used in traditional medicine and in adjuvant therapy for the treatment of numerous diseases. The objective of this study was to investigate the antitumor effect of one purified bioactive fraction of U.tomentosa bark on cell proliferation in two human bladder cancer cell lines, T24 and RT4. Quinovic acid glycosides purified fraction (QAPF) of U.tomentosa decreased the growth and viability of both T24 and RT4 cell lines. In T24 cells, QAPF induced apoptosis by activating caspase-3 and NF-κB. Further study showed that this fraction does not induce cell cycle arrest and does not alter PTEN and ERK levels. In conclusion, we demonstrated that QAPF of U.tomentosa has a potent inhibitory effect on the growth of human bladder cancer cell lines by inducing apoptosis through modulation of NF-κB, and we suggest that QAPF may become a potential therapeutic agent for the prevention and/or treatment of this cancer. PMID:24607820

  3. Role of fatty acid transport protein 4 in oleic acid-induced glucagon-like peptide-1 secretion from murine intestinal L cells

    PubMed Central

    Poreba, M. A.; Dong, C. X.; Li, S. K.; Stahl, A.; Miner, J. H.

    2012-01-01

    The antidiabetic intestinal L cell hormone glucagon-like peptide-1 (GLP-1) enhances glucose-dependent insulin secretion and inhibits gastric emptying. GLP-1 secretion is stimulated by luminal oleic acid (OA), which crosses the cell membrane by an unknown mechanism. We hypothesized that L cell fatty acid transport proteins (FATPs) are essential for OA-induced GLP-1 release. Therefore, the murine GLUTag L cell model was used for immunoblotting, [3H]OA uptake assay, and GLP-1 secretion assay as determined by radioimmunoassay following treatment with OA ± phloretin, sulfo-N-succinimidyl oleate, or siRNA against FATP4. FATP4−/− and cluster-of-differentiation 36 (CD36)−/− mice received intraileal OA, and plasma GLP-1 was measured by sandwich immunoassay. GLUTag cells were found to express CD36, FATP1, FATP3, and FATP4. The cells demonstrated specific 3H[OA] uptake that was dose-dependently inhibited by 500 and 1,000 μM unlabeled OA (P < 0.001). Cell viability was not altered by treatment with OA. Phloretin and sulfo-N-succinimidyl oleate, inhibitors of protein-mediated transport and CD36, respectively, also decreased [3H]OA uptake, as did knockdown of FATP4 by siRNA transfection (P < 0.05–0.001). OA dose-dependently increased GLP-1 secretion at 500 and 1,000 μM (P < 0.001), whereas phloretin, sulfo-N-succinimidyl oleate, and FATP4 knockdown decreased this response (P < 0.05–0.01). FATP4−/− mice displayed lower plasma GLP-1 at 60 min in response to intraileal OA (P < 0.05), whereas, unexpectedly, CD36−/− mice displayed higher basal GLP-1 levels (P < 0.01) but a normal response to intraileal OA. Together, these findings demonstrate a key role for FATP4 in OA-induced GLP-1 secretion from the murine L cell in vitro and in vivo, whereas the precise role of CD36 remains unclear. PMID:22871340

  4. Pancreatic cancer-specific cell death induced in vivo by cytoplasmic-delivered polyinosine-polycytidylic acid

    PubMed Central

    Bhoopathi, Praveen; Quinn, Bridget A.; Gui, Qin; Shen, Xue-Ning; Grossman, Steven R.; Das, Swadesh K.; Sarkar, Devanand; Fisher, Paul B.; Emdad, Luni

    2014-01-01

    Polyinosine-polycytidylic acid (pIC) is a synthetic dsRNA that acts as an immune agonist of TLR3 and RLR to activate dendritic and NK cells that can kill tumor cells. pIC can also trigger apoptosis in pancreatic ductal adenocarcinoma cells but its mechanism of action is obscure. In this study, we investigated the potential therapeutic activity of a formulation of pIC with polyethylenimine ([pIC]PEI) in PDAC and investigated its mechanism of action. [pIC]PEI stimulated apoptosis in PDAC cells without affecting normal pancreatic epithelial cells. Mechanistically, [pIC]PEI repressed XIAP and survivin expression and activated an immune response by inducing MDA-5, RIG-I and NOXA. Phosphorylation of AKT was inhibited by [pIC]PEI in PDAC and this event was critical for stimulating apoptosis through XIAP and survivin degradation. In vivo administration of [pIC]PEI inhibited tumor growth via AKT-mediated XIAP degradation in both subcutaneous and quasi-orthotopic-models of PDAC. Taken together, these results offer a preclinical proof-of-concept for the evaluation of [pIC]PEI as an immunochemotherapy to treat pancreatic cancer. PMID:25205107

  5. Retinoic Acid Receptor α Mediates All-trans-retinoic Acid-induced Klf4 Gene Expression by Regulating Klf4 Promoter Activity in Vascular Smooth Muscle Cells*

    PubMed Central

    Shi, Jian-hong; Zheng, Bin; Chen, Si; Ma, Guo-yan; Wen, Jin-kun

    2012-01-01

    The transcription factor Krüppel-like factor 4 (KLF4) plays a critical role in vascular smooth muscle cell (VSMC) differentiation induced by all-trans-retinoic acid (ATRA). Although it has been demonstrated that ATRA stimulation augments both KLF4 protein and mRNA levels in VSMCs, the molecular mechanisms by which ATRA regulates Klf4 transcription are unknown. In this study, we examined the roles of ATRA-selective nuclear retinoic acid receptors (RARs) in the transcriptional regulation of Klf4. The introduction of small interfering RNA and an RAR antagonist demonstrated that RARα, but not RARβ or RARγ, mediated ATRA-induced Klf4 expression. A luciferase assay for the Klf4 promoter showed that three GC boxes in the proximal Klf4 promoter were indispensible for ATRA-induced Klf4 transcription and that RARα enhanced Klf4 promoter activity in a GC box-dependent manner. Furthermore, chromatin immunoprecipitation and oligonucleotide pulldown assays demonstrated that the transcription factors KLF4, Sp1, and YB1 directly bound to the GC boxes of the proximal Klf4 promoter. Upon RARα agonist stimulation, RARα was recruited to the Klf4 promoter through its interaction with KLF4, Sp1, and YB1 to form a transcriptional activation complex on the three GC boxes of the Klf4 promoter. These results suggest that RARα serves as an essential co-activator for ATRA signaling and that the recruitment of RARα to the KLF4-Sp1-YB1 complex, which leads to Klf4 expression in VSMCs, is independent of a retinoic acid response element. PMID:22337869

  6. Bryonolic Acid, a Triterpenoid, Protect Against N-methyl-d-Aspartate-Induced Neurotoxicity in PC12 Cells.

    PubMed

    Que, Jinhua; Ye, Miao; Zhang, Yuqin; Xu, Wen; Li, Huang; Xu, Wei; Chu, Kedan

    2016-01-01

    Calcium overload is considered to be one of the mechanisms of cerebral ischemia. Ca(2+) influx and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and cAMP response element-binding protein (CREB) phosphorylation are considered to be involved in N-Methyl-d-aspartate (NMDA)-induced apoptosis process. This study investigated the neuroprotective effects of bryonolic acid (BA) in an NMDA-induced rat adrenal pheochromocytoma cell line (PC12) cells and the potential mechanism. PC12 was treated by NMDA to establish an excitotoxicity model. BA (110,100 and 1000 μM final concentration) was added to the medium 24 h prior to the addition of NMDA. Subsequently, a methyl thiazolyl tetrazolium (MTT) assay and a lactate dehydrogenase (LDH) release were performed. Ca(2+) concentration was demonstrated using a scanning-dual wavelength fluorimetric method. In addition, protein and mRNA levels were determined via Western blot and real-time PCR. In the presence of BA, MTT assay and LDH assay showed that more cells were viable in comparison with the NMDA group. Moreover, the concentration of Ca(2+) decreased with the addition of BA in culture. Furthermore, BA could upregulate protein expressions of Bcl-2, p-CREB, and p-CaMKII and downregulate protein expression of Bax. The mRNA results showed that the pattern of mRNA expression were similar to their respective protein levels. All these results indicate that BA protected PC12 cells against NMDA-induced apoptosis by inhibiting Ca(2+) influx and regulating gene expression in the Ca(2+)-CaMKII-CREB signal pathway. Therefore, the present study supports the notion that BA may be a promising neuroprotective agent for the treatment of cerebral ischemia disease. PMID:27043504

  7. Prostanoid-induced expression of matrix metalloproteinase-1 messenger ribonucleic acid in rat osteosarcoma cells

    NASA Technical Reports Server (NTRS)

    Clohisy, J. C.; Connolly, T. J.; Bergman, K. D.; Quinn, C. O.; Partridge, N. C.

    1994-01-01

    Individual prostanoids have distinct potencies in activating intracellular signaling pathways and regulating gene expression in osteoblastic cells. The E-series prostaglandins (PGs) are known to stimulate matrix metalloproteinase-1 (MMP-1) synthesis and secretion in certain rodent and human osteoblastic cells, yet the intracellular events involved remain unclear. To further characterize this response and its signal transduction pathway(s), we examined prostanoid-induced expression of the MMP-1 gene in the rat osteoblastic osteosarcoma cell line UMR 106-01. Northern blot analysis demonstrated that prostaglandin E2 (PGE2) and PGE1 were very potent stimulators (40-fold) of MMP-1 transcript abundance, PGF2 alpha and prostacyclin were weak stimulators (4-fold), and thromboxane-B2 had no effect. The marked increase in MMP-1 transcript abundance after PGE2 treatment was first detected at 2 h, became maximal at 4 h, and persisted beyond 24 h. This response was dose dependent and elicited maximal and half-maximal effects with concentrations of 10(-6) and 0.6 x 10(-7) M, respectively. Cycloheximide, a protein synthesis inhibitor, completely blocked this effect of PGE2, suggesting that the expression of other genes is required. Nuclear run-on experiments demonstrated that PGE2 rapidly activates MMP-1 gene transcription, with a maximal increase at 2-4 h. The second messenger analog, 8-bromo-cAMP, mimicked the effects of PGE2 by stimulating a dose-dependent increase in MMP-1 messenger RNA (mRNA) levels, with a maximal effect quantitatively similar to that observed with PGE2. Thus, in UMR 106-01 cells, different prostanoids have distinct potencies in stimulating MMP-1 mRNA abundance. Our data suggest that PGE2 stimulation of MMP-1 synthesis is due to activation of MMP-1 gene transcription and a subsequent marked increase in MMP-1 mRNA abundance. This effect is dependent on de novo protein synthesis and is mimicked by protein kinase-A activation.

  8. Retinoic acid treated human dendritic cells induce T regulatory cells via the expression of CD141 and GARP which is impaired with age.

    PubMed

    Agrawal, Sudhanshu; Ganguly, Sreerupa; Tran, Alexander; Sundaram, Padmaja; Agrawal, Anshu

    2016-06-01

    Aged subjects display increased susceptibility to mucosal diseases. Retinoic Acid (RA) plays a major role in inducing tolerance in the mucosa. RA acts on Dendritic cells (DCs) to induce mucosal tolerance. Here we compared the response of DCs from aged and young individuals to RA with a view to understand the role of DCs in age-associated increased susceptibility to mucosal diseases. Our investigations revealed that compared to young DCs, RA stimulated DCs from aged subjects are defective in inducing IL-10 and T regulatory cells. Examinations of the underlying mechanisms indicated that RA exposure led to the upregulation of CD141 and GARP on DCs which rendered the DCs tolerogenic. CD141(hi), GARP(+) DCs displayed enhanced capacity to induce T regulatory cells compared to CD141(lo) and GARP(-) DCs. Unlike RA stimulated DCs from young, DCs from aged subjects exhibited diminished upregulation of both CD141 and GARP. The percentage of DCs expressing CD141 and GARP on RA treatment was significantly reduced in DCs from aged individuals. Furthermore, the remaining CD141(hi), GARP(+) DCs from aged individuals were also deficient in inducing T regs. In summary, reduced response of aged DCs to RA enhances mucosal inflammation in the elderly, increasing their susceptibility to mucosal diseases. PMID:27244900

  9. Retinoic acid treated human dendritic cells induce T regulatory cells via the expression of CD141 and GARP which is impaired with age

    PubMed Central

    Agrawal, Sudhanshu; Ganguly, Sreerupa; Tran, Alexander; Sundaram, Padmaja; Agrawal, Anshu

    2016-01-01

    Aged subjects display increased susceptibility to mucosal diseases. Retinoic Acid (RA) plays a major role in inducing tolerance in the mucosa. RA acts on Dendritic cells (DCs) to induce mucosal tolerance. Here we compared the response of DCs from aged and young individuals to RA with a view to understand the role of DCs in age-associated increased susceptibility to mucosal diseases. Our investigations revealed that compared to young DCs, RA stimulated DCs from aged subjects are defective in inducing IL-10 and T regulatory cells. Examinations of the underlying mechanisms indicated that RA exposure led to the upregulation of CD141 and GARP on DCs which rendered the DCs tolerogenic. CD141hi, GARP+ DCs displayed enhanced capacity to induce T regulatory cells compared to CD141lo and GARP− DCs. Unlike RA stimulated DCs from young, DCs from aged subjects exhibited diminished upregulation of both CD141 and GARP. The percentage of DCs expressing CD141 and GARP on RA treatment was significantly reduced in DCs from aged individuals. Furthermore, the remaining CD141hi, GARP+ DCs from aged individuals were also deficient in inducing T regs. In summary, reduced response of aged DCs to RA enhances mucosal inflammation in the elderly, increasing their susceptibility to mucosal diseases. PMID:27244900

  10. Polyglycolic acid induced inflammation

    PubMed Central

    Ceonzo, Kathleen; Gaynor, Anne; Shaffer, Lisa; Kojima, Koji; Vacanti, Charles A.; Stahl, Gregory L.

    2005-01-01

    Tissue and organ replacement have quickly outpaced available supply. Tissue bioengineering holds the promise for additional tissue availability. Various scaffolds are currently used, whereas polyglycolic acid (PGA), which is currently used in absorbable sutures and orthopedic pins, provides an excellent support for tissue development. Unfortunately, PGA can induce a local inflammatory response following implantation, so we investigated the molecular mechanism of inflammation in vitro and in vivo. Degraded PGA induced an acute peritonitis, characterized by neutrophil (PMN) infiltration following intraperitoneal injection in mice. Similar observations were observed using the metabolite of PGA, glycolide. Dissolved PGA or glycolide, but not native PGA, activated the classical complement pathway in human sera, as determined by classical complement pathway hemolytic assays, C3a and C5a production, C3 and immunoglobulin deposition. To investigate whether these in vitro observations translated to in vivo findings, we used genetically engineered mice. Intraperitoneal administration of glycolide or dissolved PGA in mice deficient in C1q, factor D, C1q and factor D or C2 and factor B demonstrated significantly reduced PMN infiltration compared to congenic controls (WT). Mice deficient in C6 also demonstrated acute peritonitis. However, treatment of WT or C6 deficient mice with a monoclonal antibody against C5 prevented the inflammatory response. These data suggest that the hydrolysis of PGA to glycolide activates the classical complement pathway. Further, complement is amplified via the alternative pathway and inflammation is induced by C5a generation. Inhibition of C5a may provide a potential therapeutic approach to limit the inflammation associated with PGA derived materials following implantation. PMID:16548688

  11. Photodynamic therapy with 5-aminoolevulinic acid-induced porphyrins and DMSO/EDTA for basal cell carcinoma

    NASA Astrophysics Data System (ADS)

    Warloe, Trond; Peng, Qian; Heyerdahl, Helen; Moan, Johan; Steen, Harald B.; Giercksky, Karl-Erik

    1995-03-01

    Seven hundred sixty three basal cell carcinomas (BCCs) in 122 patients were treated by photodynamic therapy by 5-aminolevulinic acid (ALA) in cream topically applied, either alone, in combination with dimethyl sulphoxide (DMSO) and ethylenediaminetetraacetic acid disodium salt (EDTA), or with DMSO as a pretreatment. After 3 hours cream exposure 40 - 200 Joules/cm2 of 630 nm laser light was given. Fluorescence imaging of biopsies showed highly improved ALA penetration depth and doubled ALA-induced porphyrin production using DMSO/EDTA. Treatment response was recorded after 3 months. After a single treatment 90% of 393 superficial lesions responded completely, independent of using DMSO/EDTA. In 363 nodulo-ulcerative lesions the complete response rate increased from 67% to above 90% with DMSO/EDTA for lesions less than 2 mm thickness and from 34% to about 50% for lesions thicker than 2 mm. Recurrence rate observed during a follow-up period longer than 12 months was 2 - 5%. PDT of superficial thin BCCs with ALA-induced porphyrins and DMSO/EDTA equals surgery and radiotherapy with respect to cure rate and recurrence. Cosmetic results of ALA-based PDT seemed to be better than those after other therapies. In patients with the nevoid BCC syndrome the complete response rate after PDT was far lower.

  12. Phosphatidic acid mobilized by phospholipase D is involved in the phorbol 12-myristate 13-acetate-induced G2 delay of A431 cells.

    PubMed Central

    Kaszkin, M; Richards, J; Kinzel, V

    1996-01-01

    This study was aimed at gaining an understanding of metabolic events responsible for the inhibition of cells in G2 phase, a known physiological restriction site in the cell cycle of multicellular organisms. In an earlier study, phosphatidic acid was proposed as an inhibitory mediator in the epidermal growth factor (EGF)-induced inhibition of A431 cells in G2 phase via the phospholipase C pathway [Kaszkin, Richards and Kinzel (1992) Cancer Res. 52, 5627-5634]. We show here that the phorbol ester phorbol 12-myristate 13-acetate (PMA) induces a reversible inhibition of the G2/M transition in A431 cells under conditions of phospholipase D-catalysed phosphatidic acid formation. Such PMA-induced inhibition in G2 phase is largely attenuated in the presence of 1-propanol (but not of 2-propanol). In this case the amount of phosphatidic acid is reduced to almost control levels, and instead phosphatidylpropanol is formed. In the case of EGF-induced activation of a phospholipase D the amount of phosphatidic acid is only slightly decreased in the presence of a primary alcohol. Under these conditions the EGF-induced G2 delay was not affected. The correlation between the formation of phosphatidic acid and the G2 delay induced by PMA, as well as by an exogenous bacterial phospholipase D (from Streptomyces chromofuscus), could be supported by using synchronized cells in order to increase the population of cells in G2 phase. This study indicates that the formation of substantial amounts of phosphatidic acid immediately before entry into mitosis seems to be important for establishing a delay in the cell cycle at the G2/M border by exogenous ligands. PMID:8660273

  13. Lactic acid fermentation of germinated barley fiber and proliferative function of colonic epithelial cells in loperamide-induced rats.

    PubMed

    Jeon, Jeong Ryae; Choi, Joon Hyuk

    2010-08-01

    To develop a functional food from the dietary fiber fraction of germinated barley (Hordeum vulgare L.) (GBF), lactic acid fermentation was attempted using Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium bifidus. The quality characteristics of the lactic acid-fermented product and its effect on gastrointestinal function in an animal model were examined. The anaerobic fermentation of 1% and 2% GBF yielded lactic acid bacteria at 8.9 +/- 1.0 x 10(8) and 1.6 +/- 0.2 x 10(9) colony-forming units/mL, and it was considered acceptable for consumption by sensory assessment. To determine the effect on gastrointestinal function, Sprague-Dawley rats were fed with three types of diets: a normal chow diet and chow diets supplemented with 10% lactic acid bacteria or a yogurt fermented with 2% GBF (GBFY). The rats fed GBFY for 6 weeks gained less body weight, excreted more fecal mass, and had improved gastrointestinal transit as examined with barium sulfate. The effect of GBFY on colonic epithelial proliferation was investigated through loperamide (LPM)-induced constipation in rats. The rats fed with GBFY for 6 weeks were intraperitoneally administered LPM twice daily for 7 days. GBFY supplementation decreased fecal excretion and moisture content in feces and depleted goblet cells as observed by hematoxylin and eosin stain. However, the rats supplemented with GBFY prior to the LPM administration had enhanced bowel movement, mucin secretion, and production of short-chain fatty acids compared with values for the LPM-alone group. Immunohistochemistry revealed that the GBFY supplement increased the numbers of nuclei stained positively for Ki-67 and extended from the base to the middle zone of crypts. These results indicate that GBFY alleviates constipation via the proliferation of the colonic crypts in LPM-administered rats. PMID:20673062

  14. Chloride-inducible transient apoplastic alkalinizations induce stomata closure by controlling abscisic acid distribution between leaf apoplast and guard cells in salt-stressed Vicia faba.

    PubMed

    Geilfus, Christoph-Martin; Mithöfer, Axel; Ludwig-Müller, Jutta; Zörb, Christian; Muehling, Karl H

    2015-11-01

    Chloride stress causes the leaf apoplast transiently to alkalize, an event that is presumed to contribute to the ability of plants to adapt to saline conditions. However, the initiation of coordinated processes downstream of the alkalinization is unknown. We hypothesize that chloride-inducible pH dynamics are a key chemical feature modulating the compartmental distribution of abscisic acid (ABA) and, as a consequence, affecting stomata aperture. Apoplastic pH and stomata aperture dynamics in intact Vicia faba leaves were monitored by microscopy-based ratio imaging and porometric measurements of stomatal conductance. ABA concentrations in leaf apoplast and guard cells were compared with pH dynamics by gas-chromatography-mass-spectrometry (GC-MS) and liquid-chromatography-tandem-mass spectrometry (LC-MS/MS). Results demonstrate that, upon chloride addition to roots, an alkalizing factor that initiates the pH dynamic propagates from root to leaf in a way similar to xylem-distributed water. In leaves, it induces a systemic transient apoplastic alkalinization that causes apoplastic ABA concentration to increase, followed by an elevation of endogenous guard cell ABA. We conclude that the transient alkalinization, which is a remote effect of chloride stress, modulates the compartmental distribution of ABA between the leaf apoplast and the guard cells and, in this way, is instrumental in inducing stomata closure during the beginning of salinity. PMID:26096890

  15. Fenofibrate, a PPARα agonist, protect proximal tubular cells from albumin-bound fatty acids induced apoptosis via the activation of NF-kB

    PubMed Central

    Zuo, Nan; Zheng, Xiaoyu; Liu, Hanzhe; Ma, Xiaoli

    2015-01-01

    Albumin-bound fatty acids is the main cause of renal damage, PPARα is responsible in the metabolism of fatty acids. Previous study found that PPARα played a protective role in fatty acids overload associated tubular injury. The aim of the present study is to investigate whether fenofibrate, a PPARα ligands, could contribute to the renoprotective action in fatty acids overload proximal tubule epithelial cells. We observed in HK-2 cells that fenofibrate significantly inhibited fatty acids bound albumin (FA-BSA) induced up-regulation of MCP-1 and IL-8. Treatment with fenofibrate attenuated renal oxidative stress induced by FA-BSA as evidenced by decreased MDA level, increased SOD activity and catalase, GPx-1 expression. FA-BSA induced apoptosis of HK-2 cells were also obviously prevented by fenofibrate. Furthermore, fenofibrate significantly increased the expression of PPARα mRNA and protein in FA-BSA treated cells. Finally, the activation of NF-kB induced by FA-BSA was markedly suppressed by fenofibrate. Taken together, our study describes a renoprotective role of fenofibrate in fatty acids associated tubular toxicity, and the transcriptional activation of PPARα and suppression of NF-kB were at least partially involved. PMID:26617775

  16. Fenofibrate, a PPARα agonist, protect proximal tubular cells from albumin-bound fatty acids induced apoptosis via the activation of NF-kB.

    PubMed

    Zuo, Nan; Zheng, Xiaoyu; Liu, Hanzhe; Ma, Xiaoli

    2015-01-01

    Albumin-bound fatty acids is the main cause of renal damage, PPARα is responsible in the metabolism of fatty acids. Previous study found that PPARα played a protective role in fatty acids overload associated tubular injury. The aim of the present study is to investigate whether fenofibrate, a PPARα ligands, could contribute to the renoprotective action in fatty acids overload proximal tubule epithelial cells. We observed in HK-2 cells that fenofibrate significantly inhibited fatty acids bound albumin (FA-BSA) induced up-regulation of MCP-1 and IL-8. Treatment with fenofibrate attenuated renal oxidative stress induced by FA-BSA as evidenced by decreased MDA level, increased SOD activity and catalase, GPx-1 expression. FA-BSA induced apoptosis of HK-2 cells were also obviously prevented by fenofibrate. Furthermore, fenofibrate significantly increased the expression of PPARα mRNA and protein in FA-BSA treated cells. Finally, the activation of NF-kB induced by FA-BSA was markedly suppressed by fenofibrate. Taken together, our study describes a renoprotective role of fenofibrate in fatty acids associated tubular toxicity, and the transcriptional activation of PPARα and suppression of NF-kB were at least partially involved. PMID:26617775

  17. Apoptosis-induced cell death due to oleanolic acid in HaCaT keratinocyte cells--a proof-of-principle approach for chemopreventive drug development.

    PubMed

    George, V Cijo; Kumar, D R Naveen; Suresh, P K; Kumar, R Ashok

    2012-01-01

    Oleanolic acid (OA) is a naturally occurring triterpenoid in food materials and is a component of the leaves and roots of Olea europaea, Viscum album L., Aralia chinensis L. and more than 120 other plant species. There are several reports validating its antitumor activity against different cancer cells apart from its hepatoprotective activity. However, antitumor activity against skin cancer has not been studied well thus far. Hence the present study of effects of OA against HaCaT (immortalized keratinocyte) cells--a cell-based epithelial model system for toxicity/ethnopharmacology-based studies--was conducted. Radical scavenging activity (DPPH·) and FRAP were determined spectrophotometrically. Proliferation was assessed by XTT assay at 24, 48 and 72 hrs with exposure to various concentrations (12.5-200 μM) of OA. Apoptotic induction potential of OA was demonstrated using a cellular DNA fragmentation ELISA method. Morphological studies were also carried out to elucidate its antitumor potential. The results revealed that OA induces apoptosis by altering cellular morphology as well as DNA integrity in HaCaT cells in a dose-dependent manner, with comparatively low cytotoxicity. The moderate toxicity observed in HaCaT cells, with induction of apoptosis, possibly suggests greater involvement of programmed-cell death-mediated mechanisms. We conclude that OA has relatively low toxicity and has the potential to induce apoptosis in HaCaT cells and hence provides a substantial and sound scientific basis for further validation studies. PMID:22901164

  18. Biocontrol agents-mediated suppression of oxalic acid induced cell death during Sclerotinia sclerotiorum-pea interaction.

    PubMed

    Jain, Akansha; Singh, Akanksha; Singh, Surendra; Sarma, Birinchi Kumar; Singh, Harikesh Bahadur

    2015-05-01

    Oxalic acid (OA) is an important pathogenic factor during early Sclerotinia sclerotiorum-host interaction and might work by reducing hydrogen peroxide production (H2 O2 ). In the present investigation, oxalic acid-induced cell death in pea was studied. Pea plants treated with biocontrol agents (BCAs) viz., Pseudomonas aeruginosa PJHU15, Bacillus subtilis BHHU100, and Trichoderma harzianum TNHU27 either singly and/or in consortium acted on S. sclerotiorum indirectly by enabling plants to inhibit the OA-mediated suppression of oxidative burst via induction of H2 O2 . Our results showed that BCA treated plants upon treatment with culture filtrate of the pathogen, conferred the resistance via. significantly decreasing relative cell death of pea against S. sclerotiorum compared to control plants without BCA treatment but treated with the culture filtrate of the pathogen. The results obtained from the present study indicate that the microbes especially in consortia play significant role in protection against S. sclerotiorum by modulating oxidative burst and partially enhancing tolerance by increasing the H2 O2 generation, which is otherwise suppressed by OA produced by the pathogen. PMID:24920251

  19. Cichoric Acid Reverses Insulin Resistance and Suppresses Inflammatory Responses in the Glucosamine-Induced HepG2 Cells.

    PubMed

    Zhu, Di; Wang, Yutang; Du, Qingwei; Liu, Zhigang; Liu, Xuebo

    2015-12-30

    Cichoric acid, a caffeic acid derivative found in Echinacea purpurea, basil, and chicory, has been reported to have bioactive effects, such as anti-inflammatory, antioxidant, and preventing insulin resistance. In this study, to explore the effects of CA on regulating insulin resistance and chronic inflammatory responses, the insulin resistance model was constructed by glucosamine in HepG2 cells. CA stimulated glucosamine-mediated glucose uptake by stimulating translocation of the glucose transporter 2. Moreover, the production of reactive oxygen, the expression of COX-2 and iNOS, and the mRNA levels of TNF-α and IL-6 were attenuated. Furthermore, CA was verified to promote glucosamine-mediated glucose uptake and inhibited inflammation through PI3K/Akt, NF-κB, and MAPK signaling pathways in HepG2 cells. These results implied that CA could increase glucose uptake, improve insulin resistance, and attenuate glucosamine-induced inflammation, suggesting that CA is a potential natural nutraceutical with antidiabetic properties and anti-inflammatory effects. PMID:26592089

  20. Lactobacillus plantarum Lipoteichoic Acid Alleviates TNF-α-Induced Inflammation in the HT-29 Intestinal Epithelial Cell Line

    PubMed Central

    Kim, Hangeun; Jung, Bong Jun; Jung, Ji Hae; Kim, Joo Yun; Chung, Sung Kyun; Chung, Dae Kyun

    2012-01-01

    We recently observed that lipoteichoic acid (LTA) isolated from Lactobacillus plantarum inhibited endotoxin-mediated inflammation of the immune cells and septic shock in a mouse model. Here, we examined the inhibitory role of L. plantarum LTA (pLTA) on the inflammatory responses of intestinal epithelial cells (IEC). The human colon cell line, HT-29, increased interleukin (IL)-8 expression in response to recombinant human tumor necrosis factor (TNF)-alpha, but not in response to bacterial ligands and interferon (IFN)-gamma. TNF-α also increased the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO), and intercellular adhesion molecule 1 (ICAM-1) through activation of p38 mitogen-activated protein kinase (MAPK) from HT-29 cells. However, the inflammatory response of HT-29 on TNF-α stimulation was significantly inhibited by pLTA treatment. This pLTA-mediated inhibition accompanied the inhibition of nuclear factor (NF)-kappa B and MAPKs. Our data suggest that pLTA regulates cytokine-mediated immune responses and may be a good candidate for maintaining intestinal homeostasis against excessive inflammation. PMID:22526394

  1. Cytochrome c Trp65Ser substitution results in inhibition of acetic acid-induced programmed cell death in Saccharomyces cerevisiae.

    PubMed

    Guaragnella, Nicoletta; Passarella, Salvatore; Marra, Ersilia; Giannattasio, Sergio

    2011-11-01

    To gain further insight into the role of cytochrome c (cyt c) in yeast programmed cell death induced by acetic acid (AA-PCD), comparison was made between wild type and two mutant cells, one lacking cyt c and the other (W65Scyc1) expressing a mutant iso-1-cyt c in a form unable to reduce cyt c oxidase, with respect to occurrence of AA-PCD, cyt c release, ROS production and caspase-like activity. We show that in W65Scyc1 cells: i. no release of mutant cyt c occurs with inhibition of W65Scyc1 cell AA-PCD shown to be independent on impairment of electron flow, ii. there is a decrease in ROS production and an increase in caspase-like activity. We conclude that cyt c release does not depend on cyt c function as an electron carrier and that when still associated to the mitochondrial membrane, cyt c in its reduced form has a role in AA-PCD, by regulating ROS production and caspase-like activity. PMID:21907312

  2. Mitochondrial dysfunction: a crucial event in okadaic acid (ICV) induced memory impairment and apoptotic cell death in rat brain.

    PubMed

    Kamat, Pradeep K; Tota, Santoshkumar; Shukla, Rakesh; Ali, Shakir; Najmi, Abul Kalam; Nath, Chandishwar

    2011-12-01

    Mitochondrial abnormalities have been identified in a large proportion of neurodegenerative diseases. Recently we have reported that intracerebroventricular (ICV) administration of okadaic acid (OKA) causes memory impairment in rat. However involvement of mitochondrial function in OKA induced memory impairment and neuronal damage has not been determined. OKA (200 ng) was administered by ICV route. After 13th day of OKA administration memory function was evaluated by Morris Water Maze test. Following completion of behavioral studies on 16th day, mitochondrial membrane potential, Ca(2+) and reactive oxygen species were evaluated in mitochondrial preparation of cortex, hippocampus, striatum and cerebellum of rat brain. While ATP, mitochondrial activity, lipid peroxidation and nitrite were investigated in synaptosomal preparation of rat brain areas. The activities and mRNA expression of apoptotic factors, caspase-3 and caspase-9, were studied in rat brain regions. The neuronal damage was also confirmed by histopathological study. OKA treated rats showed memory impairment including increased Ca(2+) and reactive oxygen species and decreased mitochondrial membrane potential, ATP and mitochondrial activity in mitochondrial preparation. There was a significant increase in lipid peroxidation and nitrite in synaptosomal preparations. Preventive treatment daily for 13 days with antidementic drugs, donepezil (5 mg/kg, p.o) and memantine (10 mg/kg, p.o), significantly attenuated OKA induced mitochondrial dysfunction, apoptotic cell death, memory impairment and histological changes. Mitochondrial dysfunction appeared as a key factor in OKA induced memory impairment and apoptotic cell death. This study indicates that clinically used antidementic drugs are effective against OKA induced adverse changes at behavioral, cellular, and histological levels and mitochondrial dysfunction. PMID:21893081

  3. The Neuro-Protective Effect of the Methanolic Extract of Perilla frutescens var. japonicaand Rosmarinic Acid against H₂O₂-Induced Oxidative Stress in C6 Glial Cells.

    PubMed

    Lee, Ah Young; Wu, Ting Ting; Hwang, Bo Ra; Lee, Jaemin; Lee, Myoung-Hee; Lee, Sanghyun; Cho, Eun Ju

    2016-05-01

    Neurodegenerative diseases are often associated with oxidative damage in neuronal cells. This study was conducted to investigate the neuro-protective effect of methanolic (MeOH) extract of Perilla frutescens var. japonica and its one of the major compounds, rosmarinic acid, under oxidative stress induced by hydrogen peroxide (H₂O₂) in C6 glial cells. Exposure of C6 glial cells to H₂O₂ enhanced oxidative damage as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and thiobarbituric acid-reactive substance assays. The MeOH extract and rosmarinic acid prevented oxidative stress by increasing cell viability and inhibiting cellular lipid peroxidation. In addition, the MeOH extract and rosmarinic acid reduced H₂O₂-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the transcriptional level. Moreover, iNOS and COX-2 protein expression was down-regulated in H₂O₂-indcued C6 glial cells treated with the MeOH extract and rosmarinic acid. These findings suggest that P. frutescens var. japonica and rosmarinic acid could prevent the progression of neurodegenerative diseases through attenuation of neuronal oxidative stress. PMID:27133263

  4. Oleanolic Acid Induces Differentiation of Neural Stem Cells to Neurons: An Involvement of Transcription Factor Nkx-2.5

    PubMed Central

    Ning, You; Huang, Jianhua; Kalionis, Bill; Bian, Qin; Dong, Jingcheng; Wu, Junzhen; Tai, Xiantao; Xia, Shijin; Shen, Ziyin

    2015-01-01

    Neural stem cells (NSCs) harbor the potential to differentiate into neurons, astrocytes, and oligodendrocytes under normal conditions and/or in response to tissue damage. NSCs open a new way of treatment of the injured central nervous system and neurodegenerative disorders. Thus far, few drugs have been developed for controlling NSC functions. Here, the effect as well as mechanism of oleanolic acid (OA), a pentacyclic triterpenoid, on NSC function was investigated. We found OA significantly inhibited neurosphere formation in a dose-dependent manner and achieved a maximum effect at 10 nM. OA also reduced 5-ethynyl-2′-deoxyuridine (EdU) incorporation into NSCs, which was indicative of inhibited NSC proliferation. Western blotting analysis revealed the protein levels of neuron-specific marker tubulin-βIII (TuJ1) and Mash1 were increased whilst the astrocyte-specific marker glial fibrillary acidic protein (GFAP) decreased. Immunofluorescence analysis showed OA significantly elevated the percentage of TuJ1-positive cells and reduced GFAP-positive cells. Using DNA microarray analysis, 183 genes were differentially regulated by OA. Through transcription factor binding site analyses of the upstream regulatory sequences of these genes, 87 genes were predicted to share a common motif for Nkx-2.5 binding. Finally, small interfering RNA (siRNA) methodology was used to silence Nkx-2.5 expression and found silence of Nkx-2.5 alone did not change the expression of TuJ-1 and the percentage of TuJ-1-positive cells. But in combination of OA treatment and silence of Nkx-2.5, most effects of OA on NSCs were abolished. These results indicated that OA is an effective inducer for NSCs differentiation into neurons at least partially by Nkx-2.5-dependent mechanism. PMID:26240574

  5. Oleanolic Acid Induces Differentiation of Neural Stem Cells to Neurons: An Involvement of Transcription Factor Nkx-2.5.

    PubMed

    Ning, You; Huang, Jianhua; Kalionis, Bill; Bian, Qin; Dong, Jingcheng; Wu, Junzhen; Tai, Xiantao; Xia, Shijin; Shen, Ziyin

    2015-01-01

    Neural stem cells (NSCs) harbor the potential to differentiate into neurons, astrocytes, and oligodendrocytes under normal conditions and/or in response to tissue damage. NSCs open a new way of treatment of the injured central nervous system and neurodegenerative disorders. Thus far, few drugs have been developed for controlling NSC functions. Here, the effect as well as mechanism of oleanolic acid (OA), a pentacyclic triterpenoid, on NSC function was investigated. We found OA significantly inhibited neurosphere formation in a dose-dependent manner and achieved a maximum effect at 10 nM. OA also reduced 5-ethynyl-2'-deoxyuridine (EdU) incorporation into NSCs, which was indicative of inhibited NSC proliferation. Western blotting analysis revealed the protein levels of neuron-specific marker tubulin-βIII (TuJ1) and Mash1 were increased whilst the astrocyte-specific marker glial fibrillary acidic protein (GFAP) decreased. Immunofluorescence analysis showed OA significantly elevated the percentage of TuJ1-positive cells and reduced GFAP-positive cells. Using DNA microarray analysis, 183 genes were differentially regulated by OA. Through transcription factor binding site analyses of the upstream regulatory sequences of these genes, 87 genes were predicted to share a common motif for Nkx-2.5 binding. Finally, small interfering RNA (siRNA) methodology was used to silence Nkx-2.5 expression and found silence of Nkx-2.5 alone did not change the expression of TuJ-1 and the percentage of TuJ-1-positive cells. But in combination of OA treatment and silence of Nkx-2.5, most effects of OA on NSCs were abolished. These results indicated that OA is an effective inducer for NSCs differentiation into neurons at least partially by Nkx-2.5-dependent mechanism. PMID:26240574

  6. Influence of serum proteins on the accumulation of aminolaevulinic acid-induced protoporphyrin IX in cells in culture

    NASA Astrophysics Data System (ADS)

    Weir, M. M.; Vernon, David I.; Brown, Stanley B.

    1995-03-01

    Aminolaevulinic acid (ALA) induced porphyrin biosynthesis and the resulting in vitro phototoxicity have been determined in both SV40 transformed Swiss mouse 3T3 fibroblasts and PtK2 epithelial cells. Both cell lines respond to the addition of exogenous ALA, producing porphyrin linearly with ALA concentrations up to 0.3 mM. Notably the only accumulating porphyrin detected by HPLC was PpIX. Although the levels of PpIX are both dependent on the time and concentration used, the final intracellular porphyrin concentration is dictated by the presence of serum. When ALA is added in medium containing 10% new born calf serum, 90 - 95% of the induced porphyrin appears in the incubation medium. In the absence of serum, the intracellular PpIX levels are maintained and only under these conditions can successful in vitro PDT be performed. Gel permeation chromatography has indicated that the afflux of PpIX is promoted by the low density and high density lipoproteins, with an unknown protein (mw < 66000) contributing significantly to the effect seen. It appears that this protein is present at very low concentrations in both foetal and new born calf serum.

  7. Cell death-inducing stresses are required for defense activation in DS1-phosphatidic acid phosphatase-silenced Nicotiana benthamiana.

    PubMed

    Nakano, Masahito; Yoshioka, Hirofumi; Ohnishi, Kouhei; Hikichi, Yasufumi; Kiba, Akinori

    2015-07-20

    We previously identified DS1 plants that showed resistance to compatible Ralstonia solanacearum with accelerated defense responses. Here, we describe activation mechanisms of defense responses in DS1 plants. After inoculation with incompatible R. solanacearum 8107, DS1 plants showed hyperinduction of hypersensitive response (HR) and reactive oxygen species (ROS) generation. Transient expression of PopP1 and AvrA induced hyperinduction of HR and ROS generation. Furthermore, Pseudomonas cichorii (Pc) and a type III secretion system (TTSS)-deficient mutant of P. cichorii showed accelerated induction of HR and ROS generation. Chitin and flg22 did not induce either HR or ROS hyperaccumulation; however, INF1 accelerated HR and ROS in DS1 plants. Activation of these defense responses was closely associated with increased phosphatidic acid (PA) content. Our results show that DS1 plants exhibit PA-mediated sensitization of plant defenses and that cell death-inducing stress is required to achieve full activation of defense responses. PMID:26188395

  8. Acetyl salicylic acid protected against heat stress damage in chicken myocardial cells and may associate with induced Hsp27 expression.

    PubMed

    Wu, Di; Xu, Jiao; Song, Erbao; Tang, Shu; Zhang, Xiaohui; Kemper, N; Hartung, J; Bao, Endong

    2015-07-01

    We investigated whether acetyl salicylic acid (ASA) protects chicken myocardial cells from heat stress-mediated damage in vivo and whether the induction of Hsp27 expression is connected with this function. Pathological changes, damage-related enzyme levels, and Hsp27 expression were studied in chickens following heat stress (40 ± 1 °C for 0, 1, 2, 3, 5, 7, 10, 15, or 24 h, respectively) with or without ASA administration (1 mg/kg BW, 2 h prior). Appearance of pathological lesions such as degenerations and karyopyknosis as well as the myocardial damage-related enzyme activation indicated that heat stress causes considerable injury to the myocardial cells in vivo. Myocardial cell injury was most serious in chickens exposed to heat stress without prior ASA administration; meanwhile, ASA pretreatment acted protective function against high temperature-induced injury. Hsp27 expression was induced under all experimental conditions but was one-fold higher in the ASA-pretreated animals (0.3138 ± 0.0340 ng/mL) than in untreated animals (0.1437 ± 0.0476 ng/mL) 1 h after heat stress exposure, and such an increase was sustained over the length of the experiment. Our findings indicate that pretreatment with ASA protects chicken myocardial cells from acute heat stress in vivo with almost no obvious side effects, and this protection may involve an enhancement of Hsp27 expression. However, the detailed mechanisms underlying this effect require further investigation. PMID:25956131

  9. Retinoic Acid Induces Embryonic Stem Cell Differentiation by Altering Both Encoding RNA and microRNA Expression

    PubMed Central

    Yu, Mengying; Wu, Haibo; Ai, Zhiying; Wu, Yongyan; Liu, Hongliang; Du, Juan; Guo, Zekun; Zhang, Yong

    2015-01-01

    Retinoic acid (RA) is a vitamin A metabolite that is essential for early embryonic development and promotes stem cell neural lineage specification; however, little is known regarding the impact of RA on mRNA transcription and microRNA levels on embryonic stem cell differentiation. Here, we present mRNA microarray and microRNA high-output sequencing to clarify how RA regulates gene expression. Using mRNA microarray analysis, we showed that RA repressed pluripotency-associated genes while activating ectoderm markers in mouse embryonic stem cells (mESCs). Moreover, RA modulated the DNA methylation of mESCs by altering the expression of epigenetic-associated genes such as Dnmt3b and Dnmt3l. Furthermore, H3K4me2, a pluripotent histone modification, was repressed by RA stimulation. From microRNA sequence data, we identified two downregulated microRNAs, namely, miR-200b and miR-200c, which regulated the pluripotency of stem cells. We found that miR-200b or miR-200c deficiency suppressed the expression of pluripotent genes, including Oct4 and Nanog, and activated the expression of the ectodermal marker gene Nestin. These results demonstrate that retinoid induces mESCs to differentiate by regulating miR-200b/200c. Our findings provide the landscapes of mRNA and microRNA gene networks and indicate the crucial role of miR-200b/200c in the RA-induced differentiation of mESCs. PMID:26162091

  10. Nonesterified Fatty Acid-Induced Endoplasmic Reticulum Stress in Cattle Cumulus Oocyte Complexes Alters Cell Metabolism and Developmental Competence.

    PubMed

    Sutton-McDowall, Melanie L; Wu, Linda L Y; Purdey, Malcolm; Abell, Andrew D; Goldys, Ewa M; MacMillan, Keith L; Thompson, Jeremy G; Robker, Rebecca L

    2016-01-01

    Reduced oocyte quality has been associated with poor fertility of high-performance dairy cows during peak lactation, due to negative energy balance. We examined the role of nonesterified fatty acids (NEFAs), known to accumulate within follicular fluid during under- and overnutrition scenarios, in causing endoplasmic reticulum (ER) stress of in vitro maturated cattle cumulus-oocyte complexes (COCs). NEFA concentrations were: palmitic acid (150 μM), oleic acid (200 μM), and steric acid (75 μM). Abattoir-derived COCs were randomly matured for 24 h in the presence of NEFAs and/or an ER stress inhibitor, salubrinal. Total and hatched blastocyst yields were negatively impacted by NEFA treatment compared with controls, but this was reversed by salubrinal. ER stress markers, activating transcription factor 4 (Atf4) and heat shock protein 5 (Hspa5), but not Atf6, were significantly up-regulated by NEFA treatment within whole COCs but reversed by coincubation with salubrinal. Likewise, glucose uptake and lactate production, measured in spent medium samples, showed a similar pattern, suggesting that cumulus cell metabolism is sensitive to NEFAs via an ER stress-mediated process. In contrast, while mitochondrial DNA copy number was recovered in NEFA-treated oocytes, oocyte autofluorescence of the respiratory chain cofactor, FAD, was lower following NEFA treatment of COCs, and this was not reversed by salubrinal, suggesting the negative impact was via reduced mitochondrial function. These results reveal the significance of NEFA-induced ER stress on bovine COC developmental competence, revealing a potential therapeutic target for improving oocyte quality during peak lactation. PMID:26658709

  11. Activation of AMP-activated protein kinase by retinoic acid sensitizes hepatocellular carcinoma cells to apoptosis induced by sorafenib

    PubMed Central

    Ishijima, Naoki; Kanki, Keita; Shimizu, Hiroki; Shiota, Goshi

    2015-01-01

    To improve the outcome of cancer chemotherapy, strategies to enhance the efficacy of anticancer drugs are required. Sorafenib is the only drug to prolong overall survival of the patients with hepatocellular carcinoma (HCC), however, the outcome is still not satisfactory. Retinoids, vitamin A derivatives, have been known to exhibit inhibitory effects on various cancers including HCC. In this study, we investigated the effects of combined treatment using sorafenib and retinoids including all-trans retinoic acid (ATRA), NIK-333, and Am80 on HCC cells. Cell viability assays in six HCC cell lines, HepG2, PLC/PRF/5, HuH6, HLE, HLF, and Hep3B, revealed that 5 and 10 μM ATRA, concentrations that do not exert cytotoxic effects, enhanced the cytotoxicity of sorafenib, being much more effective than NIK-333 and Am80. We found that ATRA induced AMP-activated protein kinase activation, which was followed by reduced intracellular ATP level. Gene expression analysis revealed that ATRA decreased the expression of glycolytic genes such as GLUT-1 and LDHA. In the combination treatment using ATRA and sorafenib, increased apoptosis, followed by the activation of p38 MAPK and JNK, the upregulation and translocation of Bax to mitochondria, and the activation of caspase-3, was observed. Suppression of AMP-activated protein kinase by siRNA restored the viability of the cells treated with ATRA and sorafenib. Our results thus indicate that ATRA is useful for enhancing the cytotoxicity of sorafenib against HCC cells by regulating the energy metabolism of HCC cells. PMID:25683251

  12. Activation of AMP-activated protein kinase by retinoic acid sensitizes hepatocellular carcinoma cells to apoptosis induced by sorafenib.

    PubMed

    Ishijima, Naoki; Kanki, Keita; Shimizu, Hiroki; Shiota, Goshi

    2015-05-01

    To improve the outcome of cancer chemotherapy, strategies to enhance the efficacy of anticancer drugs are required. Sorafenib is the only drug to prolong overall survival of the patients with hepatocellular carcinoma (HCC), however, the outcome is still not satisfactory. Retinoids, vitamin A derivatives, have been known to exhibit inhibitory effects on various cancers including HCC. In this study, we investigated the effects of combined treatment using sorafenib and retinoids including all-trans retinoic acid (ATRA), NIK-333, and Am80 on HCC cells. Cell viability assays in six HCC cell lines, HepG2, PLC/PRF/5, HuH6, HLE, HLF, and Hep3B, revealed that 5 and 10 μM ATRA, concentrations that do not exert cytotoxic effects, enhanced the cytotoxicity of sorafenib, being much more effective than NIK-333 and Am80. We found that ATRA induced AMP-activated protein kinase activation, which was followed by reduced intracellular ATP level. Gene expression analysis revealed that ATRA decreased the expression of glycolytic genes such as GLUT-1 and LDHA. In the combination treatment using ATRA and sorafenib, increased apoptosis, followed by the activation of p38 MAPK and JNK, the upregulation and translocation of Bax to mitochondria, and the activation of caspase-3, was observed. Suppression of AMP-activated protein kinase by siRNA restored the viability of the cells treated with ATRA and sorafenib. Our results thus indicate that ATRA is useful for enhancing the cytotoxicity of sorafenib against HCC cells by regulating the energy metabolism of HCC cells. PMID:25683251

  13. Akt-dependent NF-kappaB activation is required for bile acids to rescue colon cancer cells from stress-induced apoptosis.

    PubMed

    Shant, Jasleen; Cheng, Kunrong; Marasa, Bernard S; Wang, Jian-Ying; Raufman, Jean-Pierre

    2009-02-01

    Conjugated secondary bile acids promote human colon cancer cell proliferation by activating EGF receptors (EGFR). We hypothesized that bile acid-induced EGFR activation also mediates cell survival by downstream Akt-regulated activation of NF-kappaB. Deoxycholyltaurine (DCT) treatment attenuated TNF-alpha-induced colon cancer cell apoptosis, and stimulated rapid and sustained NF-kappaB nuclear translocation and transcriptional activity (detected by NF-kappaB binding to an oligonucleotide consensus sequence and by activation of luciferase reporter gene constructs). Both DCT-induced NF-kappaB nuclear translocation and attenuation of TNF-alpha-stimulated apoptosis were dependent on EGFR activation. Inhibitors of nuclear translocation, proteosome activity, and IkappaBalpha kinase attenuated NF-kappaB transcriptional activity. Cell transfection with adenoviral vectors encoding a non-degradable IkappaBalpha 'super-repressor' blocked the actions of DCT on both NF-kappaB activation and TNF-alpha-induced apoptosis. Likewise, transfection with mutant akt and treatment with a chemical inhibitor of Akt attenuated effects of DCT on NF-kappaB transcriptional activity and TNF-alpha-induced apoptosis. Chemical inhibitors of Akt and NF-kappaB activation also attenuated DCT-induced rescue of H508 cells from ultraviolet radiation-induced apoptosis. Collectively, these observations indicate that, downstream of EGFR, bile acid-induced colon cancer cell survival is mediated by Akt-dependent NF-kappaB activation. These findings provide a mechanism whereby bile acids increase resistance of colon cancer to chemotherapy and radiation. PMID:19056378

  14. Akt-dependent NF-{kappa}B activation is required for bile acids to rescue colon cancer cells from stress-induced apoptosis

    SciTech Connect

    Shant, Jasleen; Cheng, Kunrong; Marasa, Bernard S.; Wang Jianying; Raufman, Jean-Pierre

    2009-02-01

    Conjugated secondary bile acids promote human colon cancer cell proliferation by activating EGF receptors (EGFR). We hypothesized that bile acid-induced EGFR activation also mediates cell survival by downstream Akt-regulated activation of NF-{kappa}B. Deoxycholyltaurine (DCT) treatment attenuated TNF-{alpha}-induced colon cancer cell apoptosis, and stimulated rapid and sustained NF-{kappa}B nuclear translocation and transcriptional activity (detected by NF-{kappa}B binding to an oligonucleotide consensus sequence and by activation of luciferase reporter gene constructs). Both DCT-induced NF-{kappa}B nuclear translocation and attenuation of TNF-{alpha}-stimulated apoptosis were dependent on EGFR activation. Inhibitors of nuclear translocation, proteosome activity, and I{kappa}B{alpha} kinase attenuated NF-{kappa}B transcriptional activity. Cell transfection with adenoviral vectors encoding a non-degradable I{kappa}B{alpha} 'super-repressor' blocked the actions of DCT on both NF-{kappa}B activation and TNF-{alpha}-induced apoptosis. Likewise, transfection with mutant akt and treatment with a chemical inhibitor of Akt attenuated effects of DCT on NF-{kappa}B transcriptional activity and TNF-{alpha}-induced apoptosis. Chemical inhibitors of Akt and NF-{kappa}B activation also attenuated DCT-induced rescue of H508 cells from ultraviolet radiation-induced apoptosis. Collectively, these observations indicate that, downstream of EGFR, bile acid-induced colon cancer cell survival is mediated by Akt-dependent NF-{kappa}B activation. These findings provide a mechanism whereby bile acids increase resistance of colon cancer to chemotherapy and radiation.

  15. Cluster of Differentiation 38 (CD38) Mediates Bile Acid-induced Acinar Cell Injury and Pancreatitis through Cyclic ADP-ribose and Intracellular Calcium Release*

    PubMed Central

    Orabi, Abrahim I.; Muili, Kamaldeen A.; Javed, Tanveer A.; Jin, Shunqian; Jayaraman, Thottala; Lund, Frances E.; Husain, Sohail Z.

    2013-01-01

    Aberrant Ca2+ signals within pancreatic acinar cells are an early and critical feature in acute pancreatitis, yet it is unclear how these signals are generated. An important mediator of the aberrant Ca2+ signals due to bile acid exposure is the intracellular Ca2+ channel ryanodine receptor. One putative activator of the ryanodine receptor is the nucleotide second messenger cyclic ADP-ribose (cADPR), which is generated by an ectoenzyme ADP-ribosyl cyclase, CD38. In this study, we examined the role of CD38 and cADPR in acinar cell Ca2+ signals and acinar injury due to bile acids using pharmacologic inhibitors of CD38 and cADPR as well as mice deficient in Cd38 (Cd38−/−). Cytosolic Ca2+ signals were imaged using live time-lapse confocal microscopy in freshly isolated mouse acinar cells during perifusion with the bile acid taurolithocholic acid 3-sulfate (TLCS; 500 μm). To focus on intracellular Ca2+ release and to specifically exclude Ca2+ influx, cells were perifused in Ca2+-free medium. Cell injury was assessed by lactate dehydrogenase leakage and propidium iodide uptake. Pretreatment with either nicotinamide (20 mm) or the cADPR antagonist 8-Br-cADPR (30 μm) abrogated TLCS-induced Ca2+ signals and cell injury. TLCS-induced Ca2+ release and cell injury were reduced by 30 and 95%, respectively, in Cd38-deficient acinar cells compared with wild-type cells (p < 0.05). Cd38-deficient mice were protected against a model of bile acid infusion pancreatitis. In summary, these data indicate that CD38-cADPR mediates bile acid-induced pancreatitis and acinar cell injury through aberrant intracellular Ca2+ signaling. PMID:23940051

  16. Effect of royal jelly on experimental colitis induced by acetic acid and alteration of mast cell distribution in the colon of rats

    PubMed Central

    Karaca, T.; Bayiroglu, F.; Yoruk, M.; Kaya, M.S.; Uslu, S.; Comba, B.; Mis, L.

    2010-01-01

    This study investigated the effects of royal jelly (RJ) on acetic acid-induced colitis in rats. Twenty adult female Wistar albino rats were divided into four treatment groups of 5 animals each, including a control group (Group I); Group II was treated orally with RJ (150 mg kg−1 body weight); Group III had acetic acid-induced colitis; and Group IV had acetic acid-induced colitis treated orally with RJ (150 mg kg−1 body weight) for 4 weeks. Colitis was induced by intracolonic instillation of 4% acetic acid; the control group received physiological saline (10 mL kg−1). Colon samples were obtained under deep anaesthesia from animals in all groups. Tissues were fixed in 10% formalin neutral buffer solution for 24 h and embedded in paraffin. Six-micrometre-thick sections were stained with Mallory’s triple stain and toluidine blue in 1% aqueous solution at pH 1.0 for 5 min (for Mast Cells). RJ was shown to protect the colonic mucosa against the injurious effect of acetic acid. Colitis (colonic damage) was confirmed histomorphometrically as significant increases in the number of mast cells (MC) and colonic erosions in rats with acetic acid-induced colitis. The RJ treatment significantly decreased the number of MC and reduced the area of colonic erosion in the colon of RJ-treated rats compared with rats with untreated colitis. The results suggest that oral treatment with RJ could be used to treat colitis. PMID:21263740

  17. Gambogic acid induces apoptosis and sensitizes TRAIL-mediated apoptosis through downregulation of cFLIPL in renal carcinoma Caki cells.

    PubMed

    Jang, Ji Hoon; Kim, Joo-Young; Sung, Eon-Gi; Kim, Eun-Ae; Lee, Tae-Jin

    2016-01-01

    Gambogic acid (GA) is a natural compound derived from brownish gamboge resin that shows a range of bioactivity, such as antitumor and antimicrobial properties. Although, GA is already known to induce cell death in a variety of cancer cells, the molecular basis for GA-induced cell death in renal cancer cells is unclear. In this study, a treatment with GA induced cell death in human renal carcinoma Caki cells in a dose-dependent manner. Treatment of Caki cells with GA decreased the levels of antiapoptotic proteins, such as Bcl-2 and XIAP in a dose-dependent manner. In addition, GA decreased the expression of the cFLIPL protein, which was downregulated at the transcriptional level without any change in the levels of cFLIPs expression. z-VAD (pan-caspase inhibitor) partially blocked GA-mediated cell death. GA-induced apoptotic cell death in Caki cells is mediated partly by the AIF translocation from the mitochondria into the nucleus via a caspase-independent pathway. In contrast, N-acetylcysteine (NAC), a ROS scavenger, had no effect on GA-induced cell death. The restoration of cFLIPL attenuated GA-induced cell death in Caki cells. Furthermore, a sub-toxic dose of GA sensitized TRAIL-mediated apoptosis in Caki cells. Pretreatment with z-VAD completely blocked GA plus TRAIL-mediated apoptosis. On the contrary, pretreatment with NAC partially inhibited GA plus TRAIL-induced apoptosis. Our findings suggested that GA induces apoptosis via the downregulation of cFLIPL and sensitized TRAIL-mediated apoptosis in Caki cells. PMID:26648023

  18. Glycolic Acid Silences Inflammasome Complex Genes, NLRC4 and ASC, by Inducing DNA Methylation in HaCaT Cells.

    PubMed

    Tang, Sheau-Chung; Yeh, Jih-I; Hung, Sung-Jen; Hsiao, Yu-Ping; Liu, Fu-Tong; Yang, Jen-Hung

    2016-03-01

    AHAs (α-hydroxy acids), including glycolic acid (GA), have been widely used in cosmetic products and superficial chemical peels. Inflammasome complex has been shown to play critical roles in inflammatory pathways in human keratinocytes. However, the anti-inflammatory mechanism of GA is still unknown. The aim of this study is to investigate the relationship between the expression of the inflammasome complex and epigenetic modification to elucidate the molecular mechanism of the anti-inflammatory effect of GA in HaCaT cells. We evaluated NLRP3, NLRC4, AIM2, and ASC inflammasome complex gene expression on real-time polymerase chain reaction (PCR). Methylation changes were detected in these genes following treatment with DNA methyltransferase (DNMT) inhibitor 5-aza-2'-deoxycytidine (5-Aza) with or without the addition of GA using methylation-specific PCR (MSP). GA inhibited the expressions of these inflammasome complex genes, and the decreases in the expressions of mRNA were reversed by 5-Aza treatment. Methylation was detected in NLRC4 and ASC on MSP, but not in NLRP3 or AIM2. GA decreased NLRC4 and ASC gene expression by increasing not only DNA methyltransferase 3B (DNMT-3B) protein level, but also total DNMT activity. Furthermore, silencing of DNMT-3B (shDNMT-3B) increased the expressions of NLRC4 and ASC. Our data demonstrated that GA treatment induces hypermethylation of promoters of NLRC4 and ASC genes, which may subsequently lead to the hindering of the assembly of the inflammasome complex in HaCaT cells. These results highlight the anti-inflammatory potential of GA-containing cosmetic agents in human skin cells and demonstrate for the first time the role of aberrant hypermethylation in this process. PMID:26784358

  19. The histone deacetylase inhibitor suberoylanilide hydroxamic acid induces apoptosis, down-regulates the CXCR4 chemokine receptor and impairs migration of chronic lymphocytic leukemia cells

    PubMed Central

    Stamatopoulos, Basile; Meuleman, Nathalie; De Bruyn, Cécile; Delforge, Alain; Bron, Dominique; Lagneaux, Laurence

    2010-01-01

    Background Chronic lymphocytic leukemia is a neoplastic disorder that arises largely as a result of defective apoptosis leading to chemoresistance. Stromal cell-derived factor-1 and its receptor, CXCR4, have been shown to play an important role in chronic lymphocytic leukemia cell trafficking and survival. Design and Methods Since histone acetylation is involved in the modulation of gene expression, we evaluated the effects of suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, on chronic lymphocytic leukemia cells and in particular on cell survival, CXCR4 expression, migration, and drug sensitization. Results Here, we showed that treatment with suberoylanilide hydroxamic acid (20 μM) for 48 hours induced a decrease in chronic lymphocytic leukemia cell viability via apoptosis (n=20, P=0.0032). Using specific caspase inhibitors, we demonstrated the participation of caspases-3, -6 and -8, suggesting an activation of the extrinsic pathway. Additionally, suberoylanilide hydroxamic acid significantly decreased CXCR4 mRNA (n=10, P=0.0010) and protein expression (n=40, P<0.0001). As a result, chronic lymphocytic leukemia cell migration in response to stromal cell-derived factor-1 (n=23, P<0.0001) or through bone marrow stromal cells was dramatically impaired. Consequently, suberoylanilide hydroxamic acid reduced the protective effect of the microenvironment and thus sensitized chronic lymphocytic leukemia cells to chemotherapy such as fludarabine. Conclusions In conclusion, suberoylanilide hydroxamic acid induces apoptosis in chronic lymphocytic leukemia cells via the extrinsic pathway and down-regulates CXCR4 expression leading to decreased cell migration. Suberoylanilide hydroxamic acid in combination with other drugs represents a promising therapeutic approach to inhibiting migration, chronic lymphocytic leukemia cell survival and potentially overcoming drug resistance. PMID:20145270

  20. Poly-γ-Glutamic Acid Induces Apoptosis via Reduction of COX-2 Expression in TPA-Induced HT-29 Human Colorectal Cancer Cells

    PubMed Central

    Shin, Eun Ju; Sung, Mi Jeong; Park, Jae Ho; Yang, Hye Jeong; Kim, Myung Sunny; Hur, Haeng Jeon; Hwang, Jin-Taek

    2015-01-01

    Poly-γ-glutamic acid (PGA) is one of the bioactive compounds found in cheonggukjang, a fast-fermented soybean paste widely utilized in Korean cooking. PGA is reported to have a number of beneficial health effects, and interestingly, it has been identified as a possible anti-cancer compound through its ability to promote apoptosis in cancer cells, although the precise molecular mechanisms remain unclear. Our findings demonstrate that PGA inhibits the pro-proliferative functions of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), a known chemical carcinogen in HT-29 human colorectal cancer cells. This inhibition was accompanied by hallmark apoptotic phenotypes, including DNA fragmentation and the cleavage of poly (ADP-ribose) polymerase (PARP) and caspase 3. In addition, PGA treatment reduced the expression of genes known to be overexpressed in colorectal cancer cells, including cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS). Lastly, PGA promoted activation of 5' adenosine monophosphate-activated protein (AMPK) in HT-29 cells. Taken together, our results suggest that PGA treatment enhances apoptosis in colorectal cancer cells, in part by modulating the activity of the COX-2 and AMPK signaling pathways. These anti-cancer functions of PGA make it a promising compound for future study. PMID:25854428

  1. Okadaic acid, a protein phosphatase inhibitor, blocks calcium changes, gene expression, and cell death induced by gibberellin in wheat aleurone cells.

    PubMed Central

    Kuo, A; Cappelluti, S; Cervantes-Cervantes, M; Rodriguez, M; Bush, D S

    1996-01-01

    The cereal aleurone functions during germination by secreting hydrolases, mainly alpha-amylase, into the starchy endosperm. Multiple signal transduction pathways exist in cereal aleurone cells that enable them to modulate hydrolase production in response to both hormonal and environmental stimuli. Gibberellic acid (GA) promotes hydrolase production, whereas abscisic acid (ABA), hypoxia, and osmotic stress reduce amylase production. In an effort to identify the components of transduction pathways in aleurone cells, we have investigated the effect of okadaic acid (OA), a protein phosphatase inhibitor, on stimulus-response coupling for GA, ABA, and hypoxia. We found that OA (100 nM) completely inhibited all the GA responses that we measured, from rapid changes in cytosolic Ca2+ through changes in gene expression and accelerated cell death. OA (100 nM) partially inhibited ABA responses, as measured by changes in the level of PHAV1, a cDNA for an ABA-induced mRNA in barley. In contrast, OA had no effect on the response to hypoxia, as measured by changes in cytosolic Ca2+ and by changes in enzyme activity and RNA levels of alcohol dehydrogenase. Our data indicate that OA-sensitive protein phosphatases act early in the transduction pathway of GA but are not involved in the response to hypoxia. These data provide a basis for a model of multiple transduction pathways in which the level of cytosolic Ca2+ is a key point of convergence controlling changes in stimulus-response coupling. PMID:8742711

  2. Asiatic acid induces endoplasmic reticulum stress and apoptotic death in glioblastoma multiforme cells both in vitro and in vivo.

    PubMed

    Kavitha, Chandagirikoppal V; Jain, Anil K; Agarwal, Chapla; Pierce, Angela; Keating, Amy; Huber, Kendra M; Serkova, Natalie J; Wempe, Michael F; Agarwal, Rajesh; Deep, Gagan

    2015-11-01

    Glioblastoma multiforme (GBM) is an untreatable malignancy. Existing therapeutic options are insufficient, and adversely affect functional and non-cancerous cells in the brain impairing different functions of the body. Therefore, there is an urgent need for additional preventive and therapeutic non-toxic drugs against GBM. Asiatic acid (AsA; 2,3,23-trihydroxy-12-ursen-28-oic acid, C30 H48 O5 ) is a natural small molecule widely used to treat various neurological disorders, and the present research investigates AsA's efficacy against GBM both in vitro and in vivo. Results showed that AsA treatment (10-100 µM) decreased the human GBM cell (LN18, U87MG, and U118MG) viability, with better efficacy than temozolomide at equimolar doses. Orally administered AsA (30 mg/kg/d) strongly decreased tumor volume in mice when administered immediately after ectopic U87MG xenograft implantation (54% decrease, P ≤ 0.05) or in mice with established xenografts (48% decrease, P ≤ 0.05) without any apparent toxicity. Importantly, AsA feeding (30 mg/kg/twice a day) also decreased the orthotopic U87MG xenografts growth in nude mice as measured by magnetic resonance imaging. Using LC/MS-MS methods, AsA was detected in mice plasma and brain tissue, confirming that AsA crosses blood-brain barrier. Mechanistic studies showed that AsA induces apoptotic death by modulating the protein expression of several apoptosis regulators (caspases, Bcl2 family members, and survivin) in GBM cells. Furthermore, AsA induced ER stress (increased GRP78 and Calpain, and decreased Calnexin and IRE1α expression), enhanced free intra-cellular calcium, and damaged cellular organization in GBM cells. These experimental results demonstrate that AsA is effective against GBM, and advocate further pre-clinical and clinical evaluations of AsA against GBM. PMID:25252179

  3. A Self-defeating Anabolic Program Leads to β-Cell Apoptosis in Endoplasmic Reticulum Stress-induced Diabetes via Regulation of Amino Acid Flux*

    PubMed Central

    Krokowski, Dawid; Han, Jaeseok; Saikia, Mridusmita; Majumder, Mithu; Yuan, Celvie L.; Guan, Bo-Jhih; Bevilacqua, Elena; Bussolati, Ovidio; Bröer, Stefan; Arvan, Peter; Tchórzewski, Marek; Snider, Martin D.; Puchowicz, Michelle; Croniger, Colleen M.; Kimball, Scot R.; Pan, Tao; Koromilas, Antonis E.; Kaufman, Randal J.; Hatzoglou, Maria

    2013-01-01

    Endoplasmic reticulum (ER) stress-induced responses are associated with the loss of insulin-producing β-cells in type 2 diabetes mellitus. β-Cell survival during ER stress is believed to depend on decreased protein synthesis rates that are mediated via phosphorylation of the translation initiation factor eIF2α. It is reported here that chronic ER stress correlated with increased islet protein synthesis and apoptosis in β-cells in vivo. Paradoxically, chronic ER stress in β-cells induced an anabolic transcription program to overcome translational repression by eIF2α phosphorylation. This program included expression of amino acid transporter and aminoacyl-tRNA synthetase genes downstream of the stress-induced ATF4-mediated transcription program. The anabolic response was associated with increased amino acid flux and charging of tRNAs for branched chain and aromatic amino acids (e.g. leucine and tryptophan), the levels of which are early serum indicators of diabetes. We conclude that regulation of amino acid transport in β-cells during ER stress involves responses leading to increased protein synthesis, which can be protective during acute stress but can lead to apoptosis during chronic stress. These studies suggest that the increased expression of amino acid transporters in islets can serve as early diagnostic biomarkers for the development of diabetes. PMID:23645676

  4. Oleanolic acid induced autophagic cell death in hepatocellular carcinoma cells via PI3K/Akt/mTOR and ROS-dependent pathway

    PubMed Central

    Shi, Yang; Song, Qingwei; Hu, Dianhe; Zhuang, Xiaohu; Yu, Shengcai

    2016-01-01

    Oleanolic acid (OA) has a wide variety of bioactivities such as hepatoprotective, anti-inflammatory and anti-cancer activity and is used for medicinal purposes in many Asian countries. In the present study, the effect of OA on induction of autophagy in human hepatocellular carcinoma HepG2 and SMC7721 cells and the related mechanisms were investigated. MTT assay showed that OA significantly inhibited HepG2 and SMC7721 cells growth. OA treatment enhanced formation of autophagic vacuoles as revealed by monodansylcadaverine (MDC) staining. At the same time, increasing punctuate distribution of microtubule-associated protein 1 light chain 3 (LC3) and an increasing ratio of LC3-II to LC3-I were also triggered by OA incubation. In addition, OA-induced cell death was signifi cantly inhibited by autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) pretreatment. And we found out that OA can suppress the PI3K/Akt1/mTOR signaling pathway. Furthermore, our data suggested that OA-triggered autophagy was ROS-dependent as demonstrated by elevated cellular ROS levels by OA treatment. When ROS was cleared by N-acetylcysteine (NAC), OA-induced LC3-II convertsion and cell death were all reversed. Taken together, our results suggest that OA exerts anticancer eff ect via autophagic cell death in hepatocellular carcinoma. PMID:27162477

  5. Valproic acid inhibits proliferation of HER2-expressing breast cancer cells by inducing cell cycle arrest and apoptosis through Hsp70 acetylation

    PubMed Central

    MAWATARI, TOSHIKI; NINOMIYA, ITASU; INOKUCHI, MASAFUMI; HARADA, SHINICHI; HAYASHI, HIRONORI; OYAMA, KATSUNOBU; MAKINO, ISAMU; NAKAGAWARA, HISATOSHI; MIYASHITA, TOMOHARU; TAJIMA, HIDEHIRO; TAKAMURA, HIROYUKI; FUSHIDA, SACHIO; OHTA, TETSUO

    2015-01-01

    Breast cancer encompasses a heterogeneous group of diseases at the molecular level. It is known that chemo-sensitivity of breast cancer depends on its molecular subtype. We investigated the growth inhibitory effect of valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, and the mechanism of this inhibition on four breast cancer cell lines with different molecular subtypes. The growth inhibitory effect of VPA in the four different breast cancer cell lines was investigated. The alteration of levels of p21 WAF1, cleaved caspase-3, acetylated Heat shock protein (Hsp) 90, acetylated Hsp70, and acetylated α-tubulin by VPA was examined in VPA-sensitive, human epidermal receptor 2 (HER2)-overexpressing SKBR3 cells. The cell growth inhibition of breast cancer cell lines was dependent on the dose and exposure time of VPA. The cell growth of HER2-overexpressing SKBR3 cell line was inhibited by VPA to a much greater degree than other cell lines studied. In SKBR3 cell line, VPA upregulated expression of p21 WAF1 and cleaved caspase-3 in the early phase. VPA markedly increased Hsp70 acetylation in a time-dependent manner but did not increase Hsp90 acetylation. Our data demonstrated that VPA inhibited cell proliferation and induced cell cycle arrest and apoptosis of HER2-overexpressing breast cancer cells. This anti-proliferation effect might be the direct function of VPA as an HDAC inhibitor. We propose an alternative mechanism whereby acetylation of Hsp70 disrupts the function of Hsp90 and leads to downregulation of its client proteins, including HER2 that might be the indirect function of VPA, in the sense that non-histone proteins are acetylated. PMID:26497673

  6. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  7. Modulation of Cell-Substrate Adhesion by Arachidonic Acid: Lipoxygenase Regulates Cell Spreading and ERK1/2-inducible Cyclooxygenase Regulates Cell Migration in NIH-3T3 Fibroblasts

    PubMed Central

    Stockton, Rebecca A.; Jacobson, Bruce S.

    2001-01-01

    Adhesion of cells to an extracellular matrix is characterized by several discrete morphological and functional stages beginning with cell-substrate attachment, followed by cell spreading, migration, and immobilization. We find that although arachidonic acid release is rate-limiting in the overall process of adhesion, its oxidation by lipoxygenase and cyclooxygenases regulates, respectively, the cell spreading and cell migration stages. During the adhesion of NIH-3T3 cells to fibronectin, two functionally and kinetically distinct phases of arachidonic acid release take place. An initial transient arachidonate release occurs during cell attachment to fibronectin, and is sufficient to signal the cell spreading stage after its oxidation by 5-lipoxygenase to leukotrienes. A later sustained arachidonate release occurs during and after spreading, and signals the subsequent migration stage through its oxidation to prostaglandins by newly synthesized cyclooxygenase-2. In signaling migration, constitutively expressed cyclooxygenase-1 appears to contribute ∼25% of prostaglandins synthesized compared with the inducible cyclooxygenase-2. Both the second sustained arachidonate release, and cyclooxygenase-2 protein induction and synthesis, appear to be regulated by the mitogen-activated protein kinase extracellular signal-regulated kinase (ERK)1/2. The initial cell attachment-induced transient arachidonic acid release that signals spreading through lipoxygenase oxidation is not sensitive to ERK1/2 inhibition by PD98059, whereas PD98059 produces both a reduction in the larger second arachidonate release and a blockade of induced cyclooxygenase-2 protein expression with concomitant reduction of prostaglandin synthesis. The second arachidonate release, and cyclooxygenase-2 expression and activity, both appear to be required for cell migration but not for the preceding stages of attachment and spreading. These data suggest a bifurcation in the arachidonic acid adhesion

  8. Attenuation of niacin-induced prostaglandin D2 generation by omega-3 fatty acids in THP-1 macrophages and Langerhans dendritic cells

    PubMed Central

    VanHorn, Justin; Altenburg, Jeffrey D; Harvey, Kevin A; Xu, Zhidong; Kovacs, Richard J; Siddiqui, Rafat A

    2012-01-01

    Niacin, also known as nicotinic acid, is an organic compound that has several cardio-beneficial effects. However, its use is limited due to the induction of a variable flushing response in most individuals. Flushing occurs from a niacin receptor mediated generation of prostaglandins from arachidonic acid metabolism. This study examined the ability of docosahexaenoic acid, eicosapentaenoic acid, and omega-3 polyunsaturated fatty acids (PUFAs), to attenuate niacin-induced prostaglandins in THP-1 macrophages. Niacin induced both PGD2 and PGE2 generation in a dose-dependent manner. Niacin also caused an increase in cytosolic calcium and activation of cytosolic phospholipase A2. The increase in PGD2 and PGE2 was reduced by both docosahexaenoic acid and eicosapentaenoic acid, but not by oleic acid. Omega-3 PUFAs efficiently incorporated into cellular phospholipids at the expense of arachidonic acid, whereas oleic acid incorporated to a higher extent but had no effect on arachidonic acid levels. Omega-3 PUFAs also reduced surface expression of GPR109A, a human niacin receptor. Furthermore, omega-3 PUFAs also inhibited the niacin-induced increase in cytosolic calcium. Niacin and/or omega-3 PUFAs minimally affected cyclooxygenase-1 activity and had no effect on cyclooxygenase -2 activity. The effects of niacin on PGD2 generation were further confirmed using Langerhans dendritic cells. Results of the present study indicate that omega-3 PUFAs reduced niacin-induced prostaglandins formation by diminishing the availability of their substrate, as well as reducing the surface expression of niacin receptors. In conclusion, this study suggests that the regular use of omega-3 PUFAs along with niacin can potentially reduce the niacin-induced flushing response in sensitive patients. PMID:22442634

  9. Spontaneous remodeling of HDL particles at acidic pH enhances their capacity to induce cholesterol efflux from human macrophage foam cells[S

    PubMed Central

    Nguyen, Su Duy; Öörni, Katariina; Lee-Rueckert, Miriam; Pihlajamaa, Tero; Metso, Jari; Jauhiainen, Matti; Kovanen, Petri T.

    2012-01-01

    HDL particles may enter atherosclerotic lesions having an acidic intimal fluid. Therefore, we investigated whether acidic pH would affect their structural and functional properties. For this purpose, HDL2 and HDL3 subfractions were incubated for various periods of time at different pH values ranging from 5.5 to 7.5, after which their protein and lipid compositions, size, structure, and cholesterol efflux capacity were analyzed. Incubation of either subfraction at acidic pH induced unfolding of apolipoproteins, which was followed by release of lipid-poor apoA-I and ensuing fusion of the HDL particles. The acidic pH-modified HDL particles exhibited an enhanced ability to promote cholesterol efflux from cholesterol-laden primary human macrophages. Importantly, treatment of the acidic pH-modified HDL with the mast cell-derived protease chymase completely depleted the newly generated lipid-poor apoA-I, and prevented the acidic pH-dependent increase in cholesterol efflux. The above-found pH-dependent structural and functional changes were stronger in HDL3 than in HDL2. Spontaneous acidic pH-induced remodeling of mature spherical HDL particles increases HDL-induced cholesterol efflux from macrophage foam cells, and therefore may have atheroprotective effects. PMID:22855736

  10. Peptide-conjugated hyaluronic acid surface for the culture of human induced pluripotent stem cells under defined conditions.

    PubMed

    Zhang, Xiaohong; Zhou, Ping; Zhao, Yinghui; Wang, Mengke; Wei, Shicheng

    2016-01-20

    Hyaluronic acid (HA) has been cross-linked to form hydrogel for potential applications in the self-renewal and differentiation of human pluripotent stem cells (hPSCs) for years. However, HA hydrogel with improved residence time and mechanical integrity that allows the survival of hPSCs under defined conditions is still much needed for clinical applications. In this study, HA was modified with methacrylate functional groups (MeHA) and cross-linked by photo-crosslinking method. After subsequent conjugation with adhesive peptide, these MeHA surfaces demonstrated performance in facilitating human induced pluripotent stem cells (hiPSCs) proliferation, and good pluripotency maintenance of hiPSCs under defined conditions. Moreover, MeHA films on glass-slides exhibited long residence time and mechanical stability throughout hiPSC culture. Our photo-crosslinkable MeHA possesses great value in accelerating the application of HA hydrogel in hiPSCs proliferation and differentiation with the conjugation of adhesive peptides. PMID:26572447

  11. Branched Chain Amino Acids Induce Apoptosis in Neural Cells without Mitochondrial Membrane Depolarization or Cytochrome c Release: Implications for Neurological Impairment Associated with Maple Syrup Urine Disease

    PubMed Central

    Jouvet, Philippe; Rustin, Pierre; Taylor, Deanna L.; Pocock, Jennifer M.; Felderhoff-Mueser, Ursula; Mazarakis, Nicholas D.; Sarraf, Catherine; Joashi, Umesh; Kozma, Mary; Greenwood, Kirsty; Edwards, A. David; Mehmet, Huseyin

    2000-01-01

    Maple syrup urine disease (MSUD) is an inborn error of metabolism caused by a deficiency in branched chain α-keto acid dehydrogenase that can result in neurodegenerative sequelae in human infants. In the present study, increased concentrations of MSUD metabolites, in particular α-keto isocaproic acid, specifically induced apoptosis in glial and neuronal cells in culture. Apoptosis was associated with a reduction in cell respiration but without impairment of respiratory chain function, without early changes in mitochondrial membrane potential and without cytochrome c release into the cytosol. Significantly, α-keto isocaproic acid also triggered neuronal apoptosis in vivo after intracerebral injection into the developing rat brain. These findings suggest that MSUD neurodegeneration may result, at least in part, from an accumulation of branched chain amino acids and their α-keto acid derivatives that trigger apoptosis through a cytochrome c-independent pathway. PMID:10793161

  12. Curcumin and Ellagic acid synergistically induce ROS generation, DNA damage, p53 accumulation and apoptosis in HeLa cervical carcinoma cells.

    PubMed

    Kumar, Devbrat; Basu, Soumya; Parija, Lucy; Rout, Deeptimayee; Manna, Sanjeet; Dandapat, Jagneshwar; Debata, Priya Ranjan

    2016-07-01

    Cervical cancer and precancerous lesions of the cervix continue to be a global health issue, and the medication for the treatment for chronic HPV infection so far has not been effective. Potential anticancer and anti HPV activities of two known phytochemicals, Curcumin and Ellagic acid were evaluated in HeLa cervical cancer cells. Curcumin is a natural compound found in the root of Curcuma longa plant and Ellagic acid a polyphenol found in fruits of strawberries, raspberries and walnuts. The combination of Curcumin and Ellagic acid at various concentrations showed better anticancer properties than either of the drug when used alone as evidenced by MTT assay. Besides this, Curcumin and Ellagic acid also restore p53, induce ROS formation and DNA damage. Mechanistic study further indicated that Curcumin and Ellagic acid show anti-HPV activity as evidenced by decrease in the HPV E6 oncoprotein on HeLa cells. PMID:27261574

  13. Ellagic acid protects endothelial cells from oxidized low-density lipoprotein-induced apoptosis by modulating the PI3K/Akt/eNOS pathway

    SciTech Connect

    Ou, Hsiu-Chung; Lee, Wen-Jane; Lee, Shin-Da; Huang, Chih-Yang; Chiu, Tsan-Hung; Tsai, Kun-Ling; Hsu, Wen-Cheng; Sheu, Wayne Huey-Herng

    2010-10-15

    Endothelial apoptosis is a driving force in atherosclerosis development. Oxidized low-density lipoprotein (oxLDL) promotes inflammatory and thrombotic processes and is highly atherogenic, as it stimulates macrophage cholesterol accumulation and foam cell formation. Previous studies have shown that the phosphatidylinositol 3-kinase/Akt/endothelial nitric oxide synthase/nitric oxide (PI3K/Akt/eNOS/NO) pathway is involved in oxLDL-induced endothelial apoptosis. Ellagic acid, a natural polyphenol found in berries and nuts, has in recent years been the subject of intense research within the fields of cancer and inflammation. However, its protective effects against oxLDL-induced injury in vascular endothelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effect of ellagic acid in human umbilical vein endothelial cells (HUVECs) exposed to oxLDL and explored the possible mechanisms. Our results showed that pretreatment with ellagic acid (5-20 {mu}M) significantly attenuated oxLDL-induced cytotoxicity, apoptotic features, and generation of reactive oxygen species (ROS). In addition, the anti-apoptotic effect of ellagic acid was partially inhibited by a PI3K inhibitor (wortmannin) and a specific eNOS inhibitor (cavtratin) but not by an ERK inhibitor (PD98059). In exploring the underlying mechanisms of ellagic acid action, we found that oxLDL decreased Akt and eNOS phosphorylation, which in turn activated NF-{kappa}B and downstream pro-apoptotic signaling events including calcium accumulation, destabilization of mitochondrial permeability, and disruption of the balance between pro- and anti-apoptotic Bcl-2 proteins. Those alterations induced by oxLDL, however, were attenuated by pretreatment with ellagic acid. The inhibition of oxLDL-induced endothelial apoptosis by ellagic acid is due at least in part to its anti-oxidant activity and its ability to modulate the PI3K/Akt/eNOS signaling pathway.

  14. EB1 Levels Are Elevated in Ascorbic Acid (AA)-stimulated Osteoblasts and Mediate Cell-Cell Adhesion-induced Osteoblast Differentiation*

    PubMed Central

    Pustylnik, Sofia; Fiorino, Cara; Nabavi, Noushin; Zappitelli, Tanya; da Silva, Rosa; Aubin, Jane E.; Harrison, Rene E.

    2013-01-01

    Osteoblasts are differentiated mesenchymal cells that function as the major bone-producing cells of the body. Differentiation cues including ascorbic acid (AA) stimulation provoke intracellular changes in osteoblasts leading to the synthesis of the organic portion of the bone, which includes collagen type I α1, proteoglycans, and matrix proteins, such as osteocalcin. During our microarray analysis of AA-stimulated osteoblasts, we observed a significant up-regulation of the microtubule (MT) plus-end binding protein, EB1, compared with undifferentiated osteoblasts. EB1 knockdown significantly impaired AA-induced osteoblast differentiation, as detected by reduced expression of osteoblast differentiation marker genes. Intracellular examination of AA-stimulated osteoblasts treated with EB1 siRNA revealed a reduction in MT stability with a concomitant loss of β-catenin distribution at the cell cortex and within the nucleus. Diminished β-catenin levels in EB1 siRNA-treated osteoblasts paralleled an increase in phospho-β-catenin and active glycogen synthase kinase 3β, a kinase known to target β-catenin to the proteasome. EB1 siRNA treatment also reduced the expression of the β-catenin gene targets, cyclin D1 and Runx2. Live immunofluorescent imaging of differentiated osteoblasts revealed a cortical association of EB1-mcherry with β-catenin-GFP. Immunoprecipitation analysis confirmed an interaction between EB1 and β-catenin. We also determined that cell-cell contacts and cortically associated EB1/β-catenin interactions are necessary for osteoblast differentiation. Finally, using functional blocking antibodies, we identified E-cadherin as a major contributor to the cell-cell contact-induced osteoblast differentiation. PMID:23740245

  15. LRD-22, a novel dual dithiocarbamatic acid ester, inhibits Aurora-A kinase and induces apoptosis and cell cycle arrest in HepG2 cells

    SciTech Connect

    Wang, Huiling; Li, Ridong; Li, Li; Ge, Zemei; Zhou, Rouli; Li, Runtao

    2015-02-27

    In this study we investigated the antitumor activity of the novel dual dithiocarbamatic acid ester LRD-22 in vitro and in vivo. Several cancer cell lines were employed to determine the effect of LRD-22 on cell growth, and the MTT assay showed there was a significant decrease in viable tumor cell numbers in the presence of LRD-22, especially in the HepG2 cell line. Colony formation assay also showed LRD-22 strongly inhibits HepG2 cell growth. Evaluation of the mechanism involved showed that inhibitory effects of LRD-22 on cell growth are due to induction of apoptosis and G2/M arrest. LRD-22 inhibited Aurora-A phosphorylation at Thr{sub 288} and subsequently impaired p53 phosphorylation at Ser{sub 315} which was associated with the proteasome degradation pathway. Tumor suppressor protein p53 is stabilized by this mechanism and accumulates through inhibition of Aurora-A kinase activity via treatment with LRD-22. In vivo study of HepG2 xenograft in nude mice also shows LRD-22 suppresses tumor growth at a concentration of 5 mg/kg without animals suffering loss of body weight. In conclusion, our results demonstrate LRD-22 acts as an Aurora-A kinase inhibitor to induce apoptosis and inhibit proliferation in HepG2 cells, and should be considered as a promising targeting agent for HCC therapy. - Highlights: • LRD-22 significantly inhibits cancer cell growth, especially in the HepG2 cell line. • The inhibitory effect of LRD-22 is due to induction of apoptosis and cell cycle arrest. • LRD-22 inhibits Aurora-A phosphorylation which results in subsequent impairment of the p53 pathway. • LRD-22 suppresses tumor growth in xenograft mice without body weight loss.

  16. PAR-2 activation enhances weak acid-induced ATP release through TRPV1 and ASIC sensitization in human esophageal epithelial cells.

    PubMed

    Wu, Liping; Oshima, Tadayuki; Shan, Jing; Sei, Hiroo; Tomita, Toshihiko; Ohda, Yoshio; Fukui, Hirokazu; Watari, Jiro; Miwa, Hiroto

    2015-10-15

    Esophageal visceral hypersensitivity has been proposed to be the pathogenesis of heartburn sensation in nonerosive reflux disease. Protease-activated receptor-2 (PAR-2) is expressed in human esophageal epithelial cells and is believed to play a role in inflammation and sensation. PAR-2 activation may modulate these responses through adenosine triphosphate (ATP) release, which is involved in transduction of sensation and pain. The transient receptor potential vanilloid receptor 1 (TRPV1) and acid-sensing ion channels (ASICs) are both acid-sensitive nociceptors. However, the interaction among these molecules and the mechanisms of heartburn sensation are still not clear. We therefore examined whether ATP release in human esophageal epithelial cells in response to acid is modulated by TRPV1 and ASICs and whether PAR-2 activation influences the sensitivity of TRPV1 and ASICs. Weak acid (pH 5) stimulated the release of ATP from primary human esophageal epithelial cells (HEECs). This effect was significantly reduced after pretreatment with 5-iodoresiniferatoxin (IRTX), a TRPV1-specific antagonist, or with amiloride, a nonselective ASIC blocker. TRPV1 and ASIC3 small interfering RNA (siRNA) transfection also decreased weak acid-induced ATP release. Pretreatment of HEECs with trypsin, tryptase, or a PAR-2 agonist enhanced weak acid-induced ATP release. Trypsin treatment led to the phosphorylation of TRPV1. Acid-induced ATP release enhancement by trypsin was partially blocked by IRTX, amiloride, or a PAR-2 antagonist. Conversely, acid-induced ATP release was augmented by PAR-2 activation through TRPV1 and ASICs. These findings suggested that the pathophysiology of heartburn sensation or esophageal hypersensitivity may be associated with the activation of PAR-2, TRPV1, and ASICs. PMID:26294672

  17. Calcium-dependent nitric oxide production is involved in the cytoprotective properties of n-acetylcysteine in glycochenodeoxycholic acid-induced cell death in hepatocytes

    SciTech Connect

    Gonzalez-Rubio, Sandra; Linares, Clara I.; Bello, Rosario I.; Gonzalez, Raul; Ferrin, Gustavo; Hidalgo, Ana B.; Munoz-Gomariz, Elisa; Rodriguez, Blanca A.; Barrera, Pilar; Ranchal, Isidora; Duran-Prado, Mario; De la Mata, Manuel; Muntane, Jordi

    2010-01-15

    The intracellular oxidative stress has been involved in bile acid-induced cell death in hepatocytes. Nitric oxide (NO) exerts cytoprotective properties in glycochenodeoxycholic acid (GCDCA)-treated hepatocytes. The study evaluated the involvement of Ca{sup 2+} on the regulation of NO synthase (NOS)-3 expression during N-acetylcysteine (NAC) cytoprotection against GCDCA-induced cell death in hepatocytes. The regulation of Ca{sup 2+} pools (EGTA or BAPTA-AM) and NO (L-NAME or NO donor) production was assessed during NAC cytoprotection in GCDCA-treated HepG2 cells. The stimulation of Ca{sup 2+} entrance was induced by A23187 in HepG2. Cell death, Ca{sup 2+} mobilization, NOS-1, -2 and -3 expression, AP-1 activation, and NO production were evaluated. GCDCA reduced intracellular Ca{sup 2+} concentration and NOS-3 expression, and enhanced cell death in HepG2. NO donor prevented, and L-NAME enhanced, GCDCA-induced cell death. The reduction of Ca{sup 2+} entry by EGTA, but not its release from intracellular stores by BAPTA-AM, enhanced cell death in GCDCA-treated cells. The stimulation of Ca{sup 2+} entrance by A23187 reduced cell death and enhanced NOS-3 expression in GCDCA-treated HepG2 cells. The cytoprotective properties of NAC were related to the recovery of intracellular Ca{sup 2+} concentration, NOS-3 expression and NO production induced by GCDCA-treated HepG2 cells. The increase of NO production by Ca{sup 2+}-dependent NOS-3 expression during NAC administration reduces cell death in GCDCA-treated hepatocytes.

  18. c-Jun N-terminal Kinase-Dependent Endoplasmic Reticulum Stress Pathway is Critically Involved in Arjunic Acid Induced Apoptosis in Non-Small Cell Lung Cancer Cells.

    PubMed

    Joo, HyeEun; Lee, Hyun Joo; Shin, Eun Ah; Kim, Hangil; Seo, Kyeong-Hwa; Baek, Nam-In; Kim, Bonglee; Kim, Sung-Hoon

    2016-04-01

    Though arjunic acid, a triterpene isolated from Terminalia arjuna, was known to have antioxidant, antiinflammatory, and cytotoxic effects, its underlying antitumor mechanism still remains unclear so far. Thus, in the present study, the molecular antitumor mechanism of arjunic acid was examined in A549 and H460 non-small cell lung cancer (NSCLC) cells. Arjunic acid exerted cytotoxicity by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay and significantly increased sub-G1 population in A549 and H460 cells by cell cycle analysis. Consistently, arjunic acid cleaved poly (ADP-ribose) polymerase (PARP), activated Bax, and phosphorylation of c-Jun N-terminal kinases (JNK), and also attenuated the expression of pro-caspase-3 and Bcl-2 in A549 and H460 cells. Furthermore, arjunic acid upregulated the expression of endoplasmic reticulum (ER) stress proteins such as IRE1 α, ATF4, p-eIF2α, and C/EBP homologous protein (CHOP) in A549 and H460 cells. Conversely, CHOP depletion attenuated the increase of sub-G1 population by arjunic acid, and also JNK inhibitor SP600125 blocked the cytotoxicity and upregulation of IRE1 α and CHOP induced by arjunic acid in A549 and H460 cells. Overall, our findings suggest that arjunic acid induces apoptosis in NSCLC cells via JNK mediated ER stress pathway as a potent chemotherapeutic agent for NSCLC. PMID:26787261

  19. Hypoxia-induced resistance to cisplatin-mediated apoptosis in osteosarcoma cells is reversed by gambogic acid independently of HIF-1α.

    PubMed

    Zhao, Wei; Xia, Shi-Qi; Zhuang, Jin-Peng; Zhang, Zhi-Peng; You, Chang-Cheng; Yan, Jing-Long; Xu, Gong-Ping

    2016-09-01

    In vitro evidence of hypoxia-induced resistance to cisplatin (CDDP)-mediated apoptosis exists in human osteosarcoma (OS). Gambogic acid (GA) is a promising chemotherapeutic compound that could increase the chemotherapeutic effectiveness of CDDP in human OS cells by inducing cell cycle arrest and promoting apoptosis. This study examined whether GA could overcome OS cell resistance to CDDP. Hypoxia significantly reduced levels of CDDP-induced apoptosis in the OS cell lines MG63 and HOS. However, combined treatment with GA and CDDP revealed a strong synergistic action between these drugs, and higher protein levels of the apoptosis-related factor Fas, cleaved caspase-8 and cleaved caspase-3 and lower expression of hypoxia-inducible factor (HIF)-1α are detected in both cell lines. Meanwhile, drug resistance was not reversed by exposure to the HIF-1α inhibitor 2-methoxyestradiol. These findings strongly suggest that hypoxia-induced resistance to CDDP is reversed by GA in OS cells independently of HIF-1α. Furthermore, in vivo studies using xenograft mouse models revealed that combination therapy with CDDP and GA exerted increased antitumor effects by inducing apoptosis. Taken together, our results demonstrate that GA may be a new potent therapeutic agent useful for targeting human OS cells. PMID:27473145

  20. Prediction and Validation of Gene Regulatory Elements Activated During Retinoic Acid Induced Embryonic Stem Cell Differentiation.

    PubMed

    Simandi, Zoltan; Horvath, Attila; Nagy, Peter; Nagy, Laszlo

    2016-01-01

    Embryonic development is a multistep process involving activation and repression of many genes. Enhancer elements in the genome are known to contribute to tissue and cell-type specific regulation of gene expression during the cellular differentiation. Thus, their identification and further investigation is important in order to understand how cell fate is determined. Integration of gene expression data (e.g., microarray or RNA-seq) and results of chromatin immunoprecipitation (ChIP)-based genome-wide studies (ChIP-seq) allows large-scale identification of these regulatory regions. However, functional validation of cell-type specific enhancers requires further in vitro and in vivo experimental procedures. Here we describe how active enhancers can be identified and validated experimentally. This protocol provides a step-by-step workflow that includes: 1) identification of regulatory regions by ChIP-seq data analysis, 2) cloning and experimental validation of putative regulatory potential of the identified genomic sequences in a reporter assay, and 3) determination of enhancer activity in vivo by measuring enhancer RNA transcript level. The presented protocol is detailed enough to help anyone to set up this workflow in the lab. Importantly, the protocol can be easily adapted to and used in any cellular model system. PMID:27403939

  1. microRNA-34a-Upregulated Retinoic Acid-Inducible Gene-I Promotes Apoptosis and Delays Cell Cycle Transition in Cervical Cancer Cells.

    PubMed

    Wang, Jing-Hua; Zhang, Le; Ma, Yu-Wei; Xiao, Jing; Zhang, Yi; Liu, Min; Tang, Hua

    2016-06-01

    The function of retinoic acid-inducible gene-I (RIG-I) in viral replication is well documented, but its function in carcinogenesis and malignancies as well as relationship with microRNAs (miRNAs) remain poorly understood. miR-34a is an antioncogene in multiple tumors. In our study, RIG-I and miR-34a suppressed cell growth, proliferation, migration, and invasion in cervical cancer cells in vitro. miR-34a was validated as a new regulator of RIG-I by binding to its 3' untranslated region and upregulating its expression level. Furthermore, we revealed that RIG-I and miR-34a enhanced apoptosis, delayed the G1/S/G2 transition of the cell cycle, and inhibited the epithelial-mesenchymal transition process to modulate malignancies in cervical cancer cells. Phenotypic rescue experiments indicated that RIG-I mediates the effects of miR-34a in HeLa and C33A cells. These findings provide new insights into the mechanisms that underlie carcinogenesis and may provide new biomarkers for the diagnosis and therapy of cervical cancer. PMID:26910120

  2. Retinoid metabolism and all-trans retinoic acid-induced growth inhibition in head and neck squamous cell carcinoma cell lines.

    PubMed Central

    Braakhuis, B. J.; Klaassen, I.; van der Leede, B. M.; Cloos, J.; Brakenhoff, R. H.; Copper, M. P.; Teerlink, T.; Hendriks, H. F.; van der Saag, P. T.; Snow, G. B.

    1997-01-01

    Retinoids can reverse potentially premalignant lesions and prevent second primary tumours in patients with head and neck squamous cell carcinoma (HNSCC). Furthermore, it has been reported that acquired resistance to all-trans retinoic acid (RA) in leukaemia is associated with decreased plasma peak levels, probably the result of enhanced retinoid metabolism. The aim of this study was to investigate the metabolism of retinoids and relate this to growth inhibition in HNSCC. Three HNSCC cell lines were selected on the basis of a large variation in the all-trans RA-induced growth inhibition. Cells were exposed to 9.5 nM (radioactive) for 4 and 24 h, and to 1 and 10 microM (nonradioactive) all-trans RA for 4, 24, 48 and 72 h, and medium and cells were analysed for retinoid metabolites. At all concentrations studied, the amount of growth inhibition was proportional to the extent at which all-trans-, 13- and 9-cis RA disappeared from the medium as well as from the cells. This turnover process coincided with the formation of a group of as yet unidentified polar retinoid metabolites. The level of mRNA of cellular RA-binding protein II (CRABP-II), involved in retinoid homeostasis, was inversely proportional to growth inhibition. These findings indicate that for HNSCC retinoid metabolism may be associated with growth inhibition. Images Figure 6 PMID:9231918

  3. Decolorization of acid and basic dyes: understanding the metabolic degradation and cell-induced adsorption/precipitation by Escherichia coli.

    PubMed

    Cerboneschi, Matteo; Corsi, Massimo; Bianchini, Roberto; Bonanni, Marco; Tegli, Stefania

    2015-10-01

    Escherichia coli strain DH5α was successfully employed in the decolorization of commercial anthraquinone and azo dyes, belonging to the general classes of acid or basic dyes. The bacteria showed an aptitude to survive at different pH values on any dye solution tested, and a rapid decolorization was obtained under aerobic conditions for the whole collection of dyes. A deep investigation about the mode of action of E. coli was carried out to demonstrate that dye decolorization mainly occurred via three different pathways, specifically bacterial induced precipitation, cell wall adsorption, and metabolism, whose weight was correlated with the chemical nature of the dye. In the case of basic azo dyes, an unexpected fast decolorization was observed after just 2-h postinoculation under aerobic conditions, suggesting that metabolism was the main mechanism involved in basic azo dye degradation, as unequivocally demonstrated by mass spectrometric analysis. The reductive cleavage of the azo group by E. coli on basic azo dyes was also further demonstrated by the inhibition of decolorization occurring when glucose was added to the dye solution. Moreover, no residual toxicity was found in the E. coli-treated basic azo dye solutions by performing Daphnia magna acute toxicity assays. The results of the present study demonstrated that E. coli can be simply exploited for its natural metabolic pathways, without applying any recombinant technology. The high versatility and adaptability of this bacterium could encourage its involvement in industrial bioremediation of textile and leather dyeing wastewaters. PMID:26062529

  4. The BRPF2/BRD1-MOZ complex is involved in retinoic acid-induced differentiation of embryonic stem cells.

    PubMed

    Cho, Hye In; Kim, Min Seong; Jang, Yeun Kyu

    2016-08-01

    The scaffold protein BRPF2 (also called BRD1), a key component of histone acetyltransferase complexes, plays an important role in embryonic development, but its function in the differentiation of embryonic stem cells (ESCs) remains unknown. In the present study, we investigated whether BRPF2 is involved in mouse ESC differentiation. BRPF2 depletion resulted in abnormal formation of embryoid bodies, downregulation of differentiation-associated genes, and persistent maintenance of alkaline phosphatase activity even after retinoic acid-induced differentiation, indicating impaired differentiation of BRPF2-depleted ESCs. We also found reduced global acetylation of histone H3 lysine 14 (H3K14) in BRPF2-depleted ESCs, irrespective of differentiation status. Further, co-immunoprecipitation analysis revealed a physical association between BRPF2 and the histone acetyltransferase MOZ in differentiated ESCs, suggesting the role of BRPF2-MOZ complexes in ESC differentiation. Together, these results suggest that BRPF2-MOZ complexes play an important role in the differentiation of ESCs via H3K14 acetylation. PMID:27256846

  5. Transcriptome analysis of the hippocampal CA1 pyramidal cell region after kainic acid-induced status epilepticus in juvenile rats.

    PubMed

    Laurén, Hanna B; Lopez-Picon, Francisco R; Brandt, Annika M; Rios-Rojas, Clarissa J; Holopainen, Irma E

    2010-01-01

    Molecular mechanisms involved in epileptogenesis in the developing brain remain poorly understood. The gene array approach could reveal some of the factors involved by allowing the identification of a broad scale of genes altered by seizures. In this study we used microarray analysis to reveal the gene expression profile of the laser microdissected hippocampal CA1 subregion one week after kainic acid (KA)-induced status epilepticus (SE) in 21-day-old rats, which are developmentally roughly comparable to juvenile children. The gene expression analysis with the Chipster software generated a total of 1592 differently expressed genes in the CA1 subregion of KA-treated rats compared to control rats. The KEGG database revealed that the identified genes were involved in pathways such as oxidative phosporylation (26 genes changed), and long-term potentiation (LTP; 18 genes changed). Also genes involved in Ca(2+) homeostasis, gliosis, inflammation, and GABAergic transmission were altered. To validate the microarray results we further examined the protein expression for a subset of selected genes, glial fibrillary protein (GFAP), apolipoprotein E (apo E), cannabinoid type 1 receptor (CB1), Purkinje cell protein 4 (PEP-19), and interleukin 8 receptor (CXCR1), with immunohistochemistry, which confirmed the transcriptome results. Our results showed that SE resulted in no obvious CA1 neuronal loss, and alterations in the expression pattern of several genes during the early epileptogenic phase were comparable to previous gene expression studies of the adult hippocampus of both experimental epileptic animals and patients with temporal lobe epilepsy (TLE). However, some changes seem to occur after SE specifically in the juvenile rat hippocampus. Insight of the SE-induced alterations in gene expression and their related pathways could give us hints for the development of new target-specific antiepileptic drugs that interfere with the progression of the disease in the juvenile age

  6. Chronological changes in acid phosphatase activity within neurons and perineuronal satellite cells of the inferior vagal ganglion of the cat induced by vagotomy.

    PubMed Central

    Glover, R A

    1982-01-01

    The hexazonium pararosaniline method was employed to describe the distribution of acid phosphatase activity, chronologically, within neurons and their investing satellite cells of the inferior vagal ganglion of the cat after vagotomy. In control ganglia, acid phosphatase activity was invariably confined to the cytoplasm of neurons and satellite cells. Reaction product was visible as distinct granules within neuronal perikarya. The cytoplasm of perineuronal satellite cells also contained reaction product but, in most instances, activity was weak and granules were difficult to distinguish. No reaction product was observed in myelin or axonal processes; nuclear staining was absent. Acid phosphatase activity was increased in ganglionic neurons as early as 24 hours after vagotomy. Increased activity in perineuronal satellite cells was not evident until 3 days post-operatively. By 15 days, activity was ubiquitously increased in the cytoplasm of both neurons and satellite cells. Evidence suggesting neuronophagia was also apparent. Between 30 and 60 days post-operatively acid phosphatase activity gradually decreased in both neurons and satellite cells until a picture comparable with that seen in control tissue sections was visible. The functional significance of these changes in acid phosphatase activity within an altered metabolic environment induced by vagotomy is discussed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:7076551

  7. Identification of albumin-bound fatty acids as the major factor in serum-induced lipid accumulation by cultured cells.

    PubMed

    Mackenzie, C G; Mackenzie, J B; Reiss, O K; Wisneski, J A

    1970-11-01

    Factors responsible for the high lipogenic activity of rabbit serum were investigated using an assay procedure based on the gravimetric determination of the 24 hr increase in cell lipid. Cellular synthesis of fatty acids was inhibited by the presence of serum in the assay medium. Approximately 90% of the increase in cell lipid produced by serum fractions was due to triglyceride accumulation. Fractionation of rabbit serum by precipitation with ammonium sulfate or by ultracentrifugation in high density medium, both indicated that three-quarters of its lipogenic activity was associated with albumin. The lipoproteins prepared by ultracentrifugation also exhibited about one-half the activity of whole serum. The lipogenic activity of albumin was confirmed by the high potency of the albumin isolated in a nearly pure form from proteins of d>1.21 by precipitation with trichloroacetic acid and extraction with ethanol. As judged from chemical and isotopic analysis, neither the lipid content nor the lipid composition of the albumin was appreciably altered during its isolation. Of the albumin-bound lipids, only the free fatty acids, as determined by DEAE column chromatography, were present in an amount sufficient to account for the observed increase in cell triglycerides. In control experiments with horse serum of low lipogenic activity, the proteins of d>1.21 also possessed low activity in conjunction with a low content of free fatty acid. However, the albumin isolated from the latter preparation exhibited the high lipogenic activity of rabbit serum albumin. Chemical and isotopic analysis of the recovered horse serum albumin revealed that its free fatty acid content was the same as that of rabbit serum albumin. These results indicated that the isolation of horse serum albumin was attended by a substantial increase in its free fatty acid content. When the rabbit serum and horse serum content of media were adjusted to provide equivalent concentrations of albumin-bound fatty

  8. Interleukin-8 (IL-8) over-production and autocrine cell activation are key factors in monomethylarsonous acid [MMA(III)]-induced malignant transformation of urothelial cells

    SciTech Connect

    Escudero-Lourdes, C.; Wu, T.; Camarillo, J.M.; Gandolfi, A.J.

    2012-01-01

    The association between chronic human exposure to arsenicals and bladder cancer development is well recognized; however, the underlying molecular mechanisms have not been fully determined. We propose that inflammatory responses can play a pathogenic role in arsenic-related bladder carcinogenesis. In previous studies, it was demonstrated that chronic exposure to 50 nM monomethylarsenous acid [MMA(III)] leads to malignant transformation of an immortalized model of urothelial cells (UROtsa), with only 3 mo of exposure necessary to trigger the transformation-related changes. In the three-month window of exposure, the cells over-expressed pro-inflammatory cytokines (IL-1β, IL-6 and IL-8), consistent with the sustained activation of NFKβ and AP1/c-jun, ERK2, and STAT3. IL-8 was over-expressed within hours after exposure to MMA(III), and sustained over-expression was observed during chronic exposure. In this study, we profiled IL-8 expression in UROtsa cells exposed to 50 nM MMA(III) for 1 to 5 mo. IL-8 expression was increased mainly in cells after 3 mo MMA(III) exposure, and its production was also found increased in tumors derived from these cells after heterotransplantation in SCID mice. UROtsa cells do express both receptors, CXCR1 and CXCR2, suggesting that autocrine cell activation could be important in cell transformation. Supporting this observation and consistent with IL-8 over-expression, CXCR1 internalization was significantly increased after three months of exposure to MMA(III). The expression of MMP-9, cyclin D1, bcl-2, and VGEF was significantly increased in cells exposed to MMA(III) for 3 mo, but these mitogen-activated kinases were significantly decreased after IL-8 gene silencing, together with a decrease in cell proliferation rate and in anchorage-independent colony formation. These results suggest a relevant role of IL-8 in MMA(III)-induced UROtsa cell transformation. -- Highlights: ► IL-8 is over-expressed in human MMA(III)-exposed urothelial

  9. Deoxycholic acid induces the overexpression of intestinal mucin, MUC2, via NF-kB signaling pathway in human esophageal adenocarcinoma cells

    PubMed Central

    Wu, JianTao; Gong, Jun; Geng, Juan; Song, YinXue

    2008-01-01

    Background Mucin alterations are a common feature of esophageal neoplasia, and alterations in MUC2 mucin have been associated with tumor progression in the esophagus. Bile acids have been linked to esophageal adenocarcinoma and mucin secretion, but their effects on mucin gene expression in human esophageal adenocarcinoma cells is unknown. Methods Human esophageal adenocarcinoma cells were treated 18 hours with 50–300 μM deoxycholic acid, chenodeoxycholic acid, or taurocholic acid. MUC2 transcription was assayed using a MUC2 promoter reporter luciferase construct and MUC2 protein was assayed by Western blot analysis. Transcription Nuclear factor-κB activity was measured using a Nuclear factor-κB reporter construct and confirmed by Western blot analysis for Nuclear factor-κB p65. Results MUC2 transcription and MUC2 protein expression were increased four to five fold by bile acids in a time and dose-dependent manner with no effect on cell viability. Nuclear factor-κB activity was also increased. Treatment with the putative chemopreventive agent aspirin, which decreased Nuclear factor-κB activity, also decreased MUC2 transcription. Nuclear factor-κB p65 siRNA decreased MUC2 transcription, confirming the significance of Nuclear factor-κB in MUC2 induction by deoxycholic acid. Calphostin C, a specific inhibitor of protein kinase C (PKC), greatly decreased bile acid induced MUC2 transcription and Nuclear factor-κB activity, whereas inhibitors of MAP kinase had no effect. Conclusion Deoxycholic acid induced MUC2 overexpression in human esophageal adenocarcinoma cells by activation of Nuclear factor-κB transcription through a process involving PKC-dependent but not PKA, independent of activation of MAP kinase. PMID:19014523

  10. Triglyceride accumulation and fatty acid profile changes in Chlorella (Chlorophyta) during high pH-induced cell cycle inhibition

    SciTech Connect

    Guckert, J.B.; Cooksey, K.E. )

    1990-03-01

    Alkaline pH stress resulted in triglyceride (TG) accumulation in Chlorella CHLOR1 and was independent of medium nitrogen or carbon levels. Based on morphological observations, alkaline pH inhibited autospore release, thus increasing the time for cell cycle completion. Autospore release has been postulated to coincide with TG utilization within the microalgal cell division cycle. The alkaline pH stress affected lipid accumulation by inhibiting the cell division cycle prior to autospore release and, therefore, prior to TG utilization. Cells inhibited in this manner showed an increase in TG accumulation but a decrease in both membrane lipid classes (glycolipid and polar lipid). Unlike TG fatty acid profiles, membrane lipid fatty acid profiles were not stable during TG accumulation. The membrane profiles became similar to the TG, i.e. less unsaturated than in the membrane lipids of unstressed control cells.

  11. S-Adenosyl-L-Methionine protects the probiotic yeast, Saccharomyces boulardii, from acid-induced cell death

    PubMed Central

    2013-01-01

    Background Saccharomyces boulardii is a probiotic yeast routinely used to prevent and to treat gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. However, only 1-3% of the yeast administered orally is recovered alive in the feces suggesting that this yeast is unable to survive the acidic environment of the gastrointestinal tract. Results We provide evidence that suggests that S. boulardii undergoes programmed cell death (PCD) in acidic environments, which is accompanied by the generation of reactive oxygen species and the appearance of caspase-like activity. To better understand the mechanism of cell death at the molecular level, we generated microarray gene expression profiles of S. boulardii cells cultured in an acidic environment. Significantly, functional annotation revealed that the up-regulated genes were significantly over-represented in cell death pathways Finally, we show that S-adenosyl-L-methionine (AdoMet), a commercially available, FDA-approved dietary supplement, enhances the viability of S. boulardii in acidic environments, most likely by preventing programmed cell death. Conclusions In toto, given the observation that many of the proven health benefits of S. boulardii are dependent on cell viability, our data suggests that taking S. boulardii and AdoMet together may be a more effective treatment for gastrointestinal disorders than taking the probiotic yeast alone. PMID:23402325

  12. Anti-cancer fatty-acid derivative induces autophagic cell death through modulation of PKM isoform expression profile mediated by bcr-abl in chronic myeloid leukemia.

    PubMed

    Shinohara, Haruka; Taniguchi, Kohei; Kumazaki, Minami; Yamada, Nami; Ito, Yuko; Otsuki, Yoshinori; Uno, Bunji; Hayakawa, Fumihiko; Minami, Yosuke; Naoe, Tomoki; Akao, Yukihiro

    2015-04-28

    The fusion gene bcr-abl develops chronic myeloid leukemia (CML), and stimulates PI3K/Akt/mTOR signaling, leading to impaired autophagy. PI3K/Akt/mTOR signaling also plays an important role in cell metabolism. The Warburg effect is a well-recognized hallmark of cancer energy metabolism, and is regulated by the mTOR/c-Myc/hnRNP/PKM signaling cascade. To develop a new strategy for the treatment of CML, we investigated the associations among bcr-abl, the cascade related to cancer energy metabolism, and autophagy induced by a fatty-acid derivative that we had previously reported as being an autophagy inducer. Here we report that a fatty-acid derivative, AIC-47, induced transcriptional repression of the bcr-abl gene and modulated the expression profile of PKM isoforms, resulting in autophagic cell death. We show that c-Myc functioned as a transcriptional activator of bcr-abl, and regulated the hnRNP/PKM cascade. AIC-47, acting through the PPARγ/β-catenin pathway, induced down-regulation of c-Myc, leading to the disruption of the bcr-abl/mTOR/hnRNP signaling pathway, and switching of the expression of PKM2 to PKM1. This switching caused autophagic cell death through an increase in the ROS level. Our findings suggest that AIC-47 induced autophagic cell death through the PPARγ/β-catenin/bcr-abl/mTOR/hnRNP/PKM cascade. PMID:25644089

  13. Platelet-activating factor induces phospholipid turnover, calcium flux, arachidonic acid liberation, eicosanoid generation, and oncogene expression in a human B cell line

    SciTech Connect

    Schulam, P.G.; Kuruvilla, A.; Putcha, G.; Mangus, L.; Franklin-Johnson, J.; Shearer, W.T. )

    1991-03-01

    Platelet-activating factor is a potent mediator of the inflammatory response. Studies of the actions of platelet-activating factor have centered mainly around neutrophils, monocytes, and platelets. In this report we begin to uncover the influence of platelet-activating factor on B lymphocytes. Employing the EBV-transformed human B cell line SKW6.4, we demonstrate that platelet-activating factor significantly alters membrane phospholipid metabolism indicated by the incorporation of 32P into phosphatidylcholine, phosphatidylinositol, and phosphatidic acid but not significantly into phosphatidylethanolamine at concentrations ranging from 10(-9) to 10(-6) M. The inactive precursor, lyso-platelet-activating factor, at a concentration as high as 10(-7) M had no effect on any of the membrane phospholipids. We also show that platelet-activating factor from 10(-12) to 10(-6) M induced rapid and significant elevation in intracellular calcium levels, whereas lyso-platelet-activating factor was again ineffective. We further demonstrate the impact of platelet-activating factor binding to B cells by measuring platelet-activating factor induced arachidonic acid release and 5-hydroxyeicosatetraenoic acid production. Moreover, platelet-activating factor was capable of inducing transcription of the nuclear proto-oncogenes c-fos and c-jun. Finally we explored the possible role of 5-hydroxyeicosatetraenoic acid as a regulator of arachidonic acid liberation demonstrating that endogenous 5-lipoxygenase activity modulates platelet-activating factor induced arachidonic acid release perhaps acting at the level of phospholipase A2. In summary, platelet-activating factor is shown here to have a direct and profound effect on a pure B cell line.

  14. Induction of aromatic amino acids and phenylpropanoid compounds in Scrophularia striata Boiss. cell culture in response to chitosan-induced oxidative stress.

    PubMed

    Kamalipourazad, Maryam; Sharifi, Mohsen; Maivan, Hassan Zare; Behmanesh, Mehrdad; Chashmi, Najmeh Ahmadian

    2016-10-01

    Manipulation of cell culture media by elicitors is one of most important strategies to inducing secondary metabolism for the production of valuable metabolites. In this investigation, inducing effect of chitosan on physiological, biochemical, and molecular parameters were investigated in cell suspension cultures of Scrophularia striata Boiss. The results showed that chitosan concentration and time of elicitation are determinants of the effectiveness of the elicitor. Accumulation of aromatic amino acids (phenylalanine [Phe] and tyrosine [Tyr]), phenylpropanoid compounds (phenolic acids [PAs] and echinacoside [ECH]), hydrogen peroxide (H2O2) production, phenylalanine ammonia-lyase (PAL) activity and gene expression, and antioxidant enzymes (superoxide dismutase [SOD], peroxidase [POX], catalase [CAT]) activities were altered by changing the exposure time of elicitation. Results showed that, upon elicitation with chitosan, oxidative events were induced, antioxidant responses of S. striata cells were boosted through enhanced activity of an effective series of scavenging enzymes (SOD, CAT, and POX), and biosynthesis of non-enzymatic antioxidants (ECH and PAs [cinnamic, p-coumaric and, caffeic acids]). The increase in amino acid content and PAL activity at early days of exposure to chitosan was related with rises in phenolic compounds. These results provide evidence that chitosan by up-regulation of PAL gene differentially improves the production of phenylpropanoid compounds, which are of medical commercial value with good biotechnological prospects. PMID:27392152

  15. Protective role of L-ascorbic acid, N-acetylcysteine and apocynin on neomycin-induced hair cell loss in zebrafish.

    PubMed

    Wu, Chia-Yen; Lee, Han-Jung; Liu, Chi-Fang; Korivi, Mallikarjuna; Chen, Hwei-Hsien; Chan, Ming-Huan

    2015-03-01

    Hair cells are highly sensitive to environmental insults and other therapeutic drugs. The adverse effects of drugs such as aminoglycosides can cause hair cell death and lead to hearing loss and imbalance. The objective of the present study was to evaluate the protective activity of L-ascorbic acid, N-acetylcysteine (NAC) and apocynin on neomycin-induced hair cell damage in zebrafish (Danio rerio) larvae at 5 days post fertilization (dpf). Results showed that the loss of hair cells within the neuromasts of the lateral lines after neomycin exposure was evidenced by a significantly lower number of neuromasts labeled with fluorescent dye FM1-43FX observed under a microscope. Co-administration with L-ascorbic acid, NAC and apocynin protected neomycin-induced hair cell loss within the neuromasts. Moreover, these three compounds reduced the production of reactive oxygen species (ROS) in neuromasts exposed to neomycin, indicating that their antioxidant action is involved. In contrast, the neuromasts were labeled with specific fluorescent dye Texas-red conjugated with neomycin to detect neomycin uptake. Interestingly, the uptake of neomycin into hair cells was not influenced by these three antioxidant compounds. These data imply that prevention of hair cell damage against neomycin by L-ascorbic acid, NAC and apocynin might be associated with inhibition of excessive ROS production, but not related to modulating neomycin uptake. Our findings conclude that L-ascorbic acid, NAC and apocynin could be used as therapeutic drugs to protect aminoglycoside-induced listening impairment after further confirmatory studies. PMID:25092119

  16. Eburicoic Acid, an Active Triterpenoid from the Fruiting Bodies of Basswood Cultivated Antrodia cinnamomea, Induces ER Stress-Mediated Autophagy in Human Hepatoma Cells

    PubMed Central

    Su, Yu-Cheng; Liu, Chun-Ting; Chu, Yung-Lin; Raghu, Rajasekaran; Kuo, Yueh-Hsiung; Sheen, Lee-Yan

    2012-01-01

    Antrodia cinnamomea, a Taiwan-specific medicinal mushroom, can manipulate biological activities, including hepatoprotection, anti-inflammation, anti-hepatitis B virus activity, anticancer activity, etc. In this study, the anti-liver cancer activity and molecular mechanisms of eburicoic acid, the second most abundant triterpenoid from the fruiting bodies of basswood cultivated Antrodia cinnamomea was investigated using the human hepatoma Hep 3B cells. The results show that eburicoic acid effectively reduced Hep 3B cell viability within 24 hours, and the IC50 was 18.4 μM, which was equivalent to 8.7 μg/mL. Besides, eburicoic acid induced conversion of LC3-I to LC3-II and a large number of autophagosomes/autolysosomes formation. In depth investigation for the molecular mechanisms, revealed that eburicoic acid firstly promoted reactive oxygen species generation and ATP depletion, leading to endoplasmic reticulum stress, followed by elevated cytosolic calcium ion concentration and BiP expression, downregulated phosphorylation of DAPK, upregulated phosphorylation of Beclin-1, JNK, and Bcl-2, and finally induced autophagy in Hep 3B cells. These results indicate that eburicoic acid has significant anti-liver cancer effects and more distinctive mechanisms. PMID:24716146

  17. Pinus densiflora Sieb. et Zucc. Alleviates Lipogenesis and Oxidative Stress during Oleic Acid-Induced Steatosis in HepG2 Cells

    PubMed Central

    Hwang, Yu-Jin; Wi, Hae-Ri; Kim, Haeng-Ran; Park, Kye Won; Hwang, Kyung-A

    2014-01-01

    Excess accumulation of lipids and oxidative stress in the liver contribute to nonalcoholic fatty liver disease (NAFLD). We hypothesized that Pinus densiflora Sieb. et Zucc. (PSZ) can protect against NAFLD by regulating lipid accumulation and oxidative stress in the liver. To investigate the effect of PSZ upon NAFLD, we used an established cellular model: HepG2 cells treated with oleic acid. Then, the extent of hepatic steatosis and oxidative stress was assessed and levels of inflammatory markers measured. Oleic acid-treated HepG2 cells, compared with controls, had greater lipid accumulation. PSZ decreased lipid accumulation by 63% in oleic acid-treated HepG2 cells. Additionally, PSZ decreased the target gene expression of lipogenesis such as sterol regulatory element binding protein-1c, fatty acid synthase, stearoyl-CoA desaturase-1, diacylglycerol O-acyltransferase-1, and acetyl-CoA carboxylase-1 by 1.75, 6.0, 2.32, 1.93 and 1.81 fold, respectively. In addition, Oleic acid-treated HepG2 cells elicited extensive accumulation of tumor necrosis factor-α (TNFα) by 4.53 fold, whereas PSZ-treated cells decreased the expression of TNFα mRNA by 1.76 fold. PSZ significantly inhibited oxidative stress induced by reactive oxygen species. These results suggest that PSZ has effects on steatosis in vitro and further studies are needed in vivo to verify the current observations. PMID:25057104

  18. Organochlorine insecticides induce NADPH oxidase-dependent reactive oxygen species in human monocytic cells via phospholipase A2/arachidonic acid.

    PubMed

    Mangum, Lee C; Borazjani, Abdolsamad; Stokes, John V; Matthews, Anberitha T; Lee, Jung Hwa; Chambers, Janice E; Ross, Matthew K

    2015-04-20

    ) levels and enhanced p47(phox) membrane localization compared to that in vehicle-treated cells. p47(phox) is a cytosolic regulatory subunit of Nox, and its phosphorylation and translocation to the NOX2 catalytic subunit in membranes is a requisite step for Nox assembly and activation. Dieldrin and trans-nonachlor treatments of monocytes also resulted in marked increases in arachidonic acid (AA) and eicosanoid production, which could be abrogated by the phospholipase A2 (PLA2) inhibitor arachidonoyltrifluoromethyl ketone (ATK) but not by calcium-independent PLA2 inhibitor bromoenol lactone. This suggested that cytosolic PLA2 plays a crucial role in the induction of Nox activity by increasing the intracellular pool of AA that activates protein kinase C, which phosphorylates p47(phox). In addition, ATK also blocked OC-induced p47(phox) serine phosphorylation and attenuated ROS levels, which further supports the notion that the AA pool liberated by cytosolic PLA2 is responsible for Nox activation. Together, the results suggest that trans-nonachlor and dieldrin are capable of increasing intracellular superoxide levels via a Nox-dependent mechanism that relies on elevated intracellular AA levels. These findings are significant because chronic activation of monocytes by environmental toxicants might contribute to pathogenic oxidative stress and inflammation. PMID:25633958

  19. Aromatic hydrocarbon receptor inhibits lysophosphatidic acid-induced vascular endothelial growth factor-A expression in PC-3 prostate cancer cells

    SciTech Connect

    Wu, Pei-Yi; Lin, Yueh-Chien; Lan, Shun-Yan; Huang, Yuan-Li; Lee, Hsinyu

    2013-08-02

    Highlights: •LPA-induced VEGF-A expression was regulated by HIF-1α and ARNT. •PI3K mediated LPA-induced VEGF-A expression. •AHR signaling inhibited LPA-induced VEGF-A expression in PC-3 cells. -- Abstract: Lysophosphatidic acid (LPA) is a lipid growth factor with multiple biological functions and has been shown to stimulate cancer cell secretion of vascular endothelial growth factor-A (VEGF-A) and trigger angiogenesis. Hypoxia-inducible factor-1 (HIF-1), a heterodimer consisting of HIF-1α and HIF-1β (also known as aromatic hydrocarbon receptor nuclear translocator (ARNT)) subunits, is an important regulator of angiogenesis in prostate cancer (PC) through the enhancement of VEGF-A expression. In this study, we first confirmed the ability of LPA to induce VEGF-A expression in PC-3 cells and then validated that LPA-induced VEGF-A expression was regulated by HIF-1α and ARNT through phosphatidylinositol 3-kinase activation. Aromatic hydrocarbon receptor (AHR), a receptor for dioxin-like compounds, functions as a transcription factor through dimerization with ARNT and was found to inhibit prostate carcinogenesis and vanadate-induced VEGF-A production. Since ARNT is a common dimerization partner of AHR and HIF-1α, we hypothesized that AHR might suppress LPA-induced VEGF-A expression in PC-3 cells by competing with HIF-1α for ARNT. Here we demonstrated that overexpression and ligand activation of AHR inhibited HIF-1-mediated VEGF-A induction by LPA treatment of PC-3 cells. In conclusion, our results suggested that AHR activation may inhibit LPA-induced VEGF-A expression in PC-3 cells by attenuating HIF-1α signaling, and subsequently, suppressing angiogenesis and metastasis of PC. These results suggested that AHR presents a potential therapeutic target for the prevention of PC metastasis.

  20. Retinoic acid-induced IgG production in TLR-activated human primary B cells involves ULK1-mediated autophagy

    PubMed Central

    Eriksen, Agnete Bratsberg; Torgersen, Maria Lyngaas; Holm, Kristine Lillebø; Abrahamsen, Greger; Spurkland, Anne; Moskaug, Jan Øivind; Simonsen, Anne; Blomhoff, Heidi Kiil

    2015-01-01

    In the present study we have established a vital role of autophagy in retinoic acid (RA)-induced differentiation of toll-like receptor (TLR)-stimulated human B cells into Ig-secreting cells. Thus, RA enhanced autophagy in TLR9- and CD180-stimulated peripheral blood B cells, as revealed by increased levels of the autophagosomal marker LC3B-II, enhanced colocalization between LC3B and the lysosomal marker Lyso-ID, by a larger percentage of cells with more than 5 characteristic LC3B puncta, and by the concomitant reduction in the level of SQSTM1/p62. Furthermore, RA induced expression of the autophagy-inducing protein ULK1 at the transcriptional level, in a process that required the retinoic acid receptor RAR. By inhibiting autophagy with specific inhibitors or by knocking down ULK1 by siRNA, the RA-stimulated IgG production in TLR9- and CD180-mediated cells was markedly reduced. We propose that the identified prominent role of autophagy in RA-mediated IgG-production in normal human B cells provides a novel mechanism whereby vitamin A exerts its important functions in the immune system. PMID:25749095

  1. Metformin-Induced Killing of Triple Negative Breast Cancer Cells is Mediated by Reduction in Fatty Acid Synthase via miRNA-193b

    PubMed Central

    Wahdan-Alaswad, Reema S.; Cochrane, Dawn R.; Spoelstra, Nicole S.; Howe, Erin N.; Edgerton, Susan M.; Anderson, Steven M.; Thor, Ann D.; Richer, Jennifer K.

    2015-01-01

    The anti-diabetic drug metformin (1,1-dimethylbiguanide hydrochloride) reduces both the incidence and mortality of several types of cancer. Metformin has been shown to selectively kill cancer stem cells and triple negative breast cancer (TNBC) cell lines are more sensitive to the effects of metformin. However, the mechanism underlying the enhanced susceptibility of TNBC to metformin had not been elucidated. Expression profiling of metformin-treated TNBC lines revealed fatty acid synthase (FASN) as one of the genes most significantly downregulated following 24 hours of treatment and a decrease in FASN protein was also observed. Since FASN is critical for de novo fatty acid synthesis, and is important for survival of TNBC, we hypothesized that FASN downregulation facilitates metformin-induced apoptosis. Profiling studies also exposed a rapid metformin-induced increase in miR-193 family members, and miR-193b was found to directly target the FASN 3′UTR. Addition of exogenous miR-193b mimic to untreated TNBC cells resulted in decreased FASN protein expression and increased apoptosis of TNBC cells, while spontaneously immortalized, non-transformed breast epithelial cells remained unaffected. Conversely, antagonizing miR-193 activity impaired the ability of metformin to decrease FASN and cause cell death. Further, the metformin-stimulated increase in miR-193 resulted in reduced mammosphere formation by TNBC lines. These studies provide mechanistic insight into the metformin-induced killing of TNBC. PMID:25213330

  2. Metformin-induced killing of triple-negative breast cancer cells is mediated by reduction in fatty acid synthase via miRNA-193b.

    PubMed

    Wahdan-Alaswad, Reema S; Cochrane, Dawn R; Spoelstra, Nicole S; Howe, Erin N; Edgerton, Susan M; Anderson, Steven M; Thor, Ann D; Richer, Jennifer K

    2014-12-01

    The anti-diabetic drug metformin (1,1-dimethylbiguanide hydrochloride) reduces both the incidence and mortality of several types of cancer. Metformin has been shown to selectively kill cancer stem cells, and triple-negative breast cancer (TNBC) cell lines are more sensitive to the effects of metformin as compared to luminal breast cancer. However, the mechanism underlying the enhanced susceptibility of TNBC to metformin has not been elucidated. Expression profiling of metformin-treated TNBC lines revealed fatty acid synthase (FASN) as one of the genes most significantly downregulated following 24 h of treatment, and a decrease in FASN protein was also observed. Since FASN is critical for de novo fatty acid synthesis and is important for the survival of TNBC, we hypothesized that FASN downregulation facilitates metformin-induced apoptosis. Profiling studies also exposed a rapid metformin-induced increase in miR-193 family members, and miR-193b directly targets the FASN 3'UTR. Addition of exogenous miR-193b mimic to untreated TNBC cells decreased FASN protein expression and increased apoptosis of TNBC cells, while spontaneously immortalized, non-transformed breast epithelial cells remained unaffected. Conversely, antagonizing miR-193 activity impaired the ability of metformin to decrease FASN and cause cell death. Further, the metformin-stimulated increase in miR-193 resulted in reduced mammosphere formation by TNBC lines. These studies provide mechanistic insight into metformin-induced killing of TNBC. PMID:25213330

  3. Fatty acid-binding protein 5 regulates diet-induced obesity via GIP secretion from enteroendocrine K cells in response to fat ingestion.

    PubMed

    Shibue, Kimitaka; Yamane, Shunsuke; Harada, Norio; Hamasaki, Akihiro; Suzuki, Kazuyo; Joo, Erina; Iwasaki, Kanako; Nasteska, Daniela; Harada, Takanari; Hayashi, Yoshitaka; Adachi, Yasuhiro; Owada, Yuji; Takayanagi, Ryoichi; Inagaki, Nobuya

    2015-04-01

    Gastric inhibitory polypeptide (GIP) is an incretin released from enteroendocrine K cells in response to nutrient intake, especially fat. GIP is one of the contributing factors inducing fat accumulation that results in obesity. A recent study shows that fatty acid-binding protein 5 (FABP5) is expressed in murine K cells and is involved in fat-induced GIP secretion. We investigated the mechanism of fat-induced GIP secretion and the impact of FABP5-related GIP response on diet-induced obesity (DIO). Single oral administration of glucose and fat resulted in a 40% reduction of GIP response to fat but not to glucose in whole body FABP5-knockout (FABP5(-/-)) mice, with no change in K cell count or GIP content in K cells. In an ex vivo experiment using isolated upper small intestine, oleic acid induced only a slight increase in GIP release, which was markedly enhanced by coadministration of bile and oleic acid together with attenuated GIP response in the FABP5(-/-) sample. FABP5(-/-) mice exhibited a 24% reduction in body weight gain and body fat mass under a high-fat diet compared with wild-type (FABP5(+/+)) mice; the difference was not observed between GIP-GFP homozygous knock-in (GIP(gfp/gfp))-FABP5(+/+) mice and GIP(gfp/gfp)-FABP5(-/-) mice, in which GIP is genetically deleted. These results demonstrate that bile efficiently amplifies fat-induced GIP secretion and that FABP5 contributes to the development of DIO in a GIP-dependent manner. PMID:25628425

  4. Tranexamic Acid Diminishes Laser-Induced Melanogenesis

    PubMed Central

    Kim, Myoung Shin; Bang, Seung Hyun; Kim, Jeong-Hwan; Shin, Hong-Ju; Choi, Jee-Ho

    2015-01-01

    Background The treatment of post-inflammatory hyperpigmentation (PIH) remains challenging. Tranexamic acid, a well-known anti-fibrinolytic drug, has recently demonstrated a curative effect towards melasma and ultraviolet-induced PIH in Asian countries. However, the precise mechanism of its inhibitory effect on melanogenesis is not fully understood. Objective In order to clarify the inhibitory effect of tranexamic acid on PIH, we investigated its effects on mouse melanocytes (i.e., melan-a cells) and human melanocytes. Methods Melan-a cells and human melanocytes were cultured with fractional CO2 laser-treated keratinocyte-conditioned media. Melanin content and tyrosinase activity were evaluated in cells treated with or without tranexamic acid. Protein levels of tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 were evaluated in melan-a cells. Signaling pathway molecules involved in melanogenesis in melanoma cells were also investigated. Results Tranexamic acid-treated melanocytes exhibited reduced melanin content and tyrosinase activity. Tranexamic acid also decreased tyrosinase, TRP-1, and TRP-2 protein levels. This inhibitory effect on melanogenesis was considered to be involved in extracellular signal-regulated kinase signaling pathways and subsequently microphthalmia-associated transcription factor degradation. Conclusion Tranexamic acid may be an attractive candidate for the treatment of PIH. PMID:26082580

  5. Chromatin Changes in Dicer-Deficient Mouse Embryonic Stem Cells in Response to Retinoic Acid Induced Differentiation

    PubMed Central

    Cooney, Austin J.; Gunaratne, Preethi H.

    2013-01-01

    Loss of Dicer, an enzyme critical for microRNA biogenesis, results in lethality due to a block in mouse embryonic stem cell (mES) differentiation. Using ChIP-Seq we found increased H3K9me2 at over 900 CpG islands in the Dicer-/-ES epigenome. Gene ontology analysis revealed that promoters of chromatin regulators to be among the most impacted by increased CpG island H3K9me2 in ES (Dicer-/-). We therefore, extended the study to include H3K4me3 and H3K27me3 marks for selected genes. We found that the ES (Dicer-/-) mutant epigenome was characterized by a shift in the overall balance between transcriptionally favorable (H3K4me3) and unfavorable (H3K27me3) marks at key genes regulating ES cell differentiation. Pluripotency genes Oct4, Sox2 and Nanog were not impacted in relation to patterns of H3K27me3 and H3K4me3 and showed no changes in the rates of transcript down-regulation in response to RA. The most striking changes were observed in regards to genes regulating differentiation and the transition from self-renewal to differentiation. An increase in H3K4me3 at the promoter of Lin28b was associated with the down-regulation of this gene at a lower rate in Dicer-/-ES as compared to wild type ES. An increase in H3K27me3 in the promoters of differentiation genes Hoxa1 and Cdx2 in Dicer-/-ES cells was coincident with an inability to up-regulate these genes at the same rate as ES upon retinoic acid (RA)-induced differentiation. We found that siRNAs Ezh2 and post-transcriptional silencing of Ezh2 by let-7g rescued this effect suggesting that Ezh2 up-regulation is in part responsible for increased H3K27me3 and decreased rates of up-regulation of differentiation genes in Dicer-/-ES. PMID:24040281

  6. Ascorbic acid supplementation down-regulates the alcohol induced oxidative stress, hepatic stellate cell activation, cytotoxicity and mRNA levels of selected fibrotic genes in guinea pigs.

    PubMed

    Abhilash, P A; Harikrishnan, R; Indira, M

    2012-02-01

    Both oxidative stress and endotoxins mediated immunological reactions play a major role in the progression of alcoholic hepatic fibrosis. Ascorbic acid has been reported to reduce alcohol-induced toxicity and ascorbic acid levels are reduced in alcoholics. Hence, we investigated the hepatoprotective action of ascorbic acid in the reversal of alcohol-induced hepatic fibrosis in male guinea pigs (n = 36), and it was compared with the animals abstenting from alcohol treatment. In comparison with the alcohol abstention group, there was a reduction in the activities of toxicity markers and levels of lipid and protein peroxidation products, expression of α-SMA, caspase-3 activity and mRNA levels of CYP2E1, TGF-β(1), TNF-α and α(1)(I) collagen in liver of the ascorbic acid-supplemented group. The ascorbic acid content in liver was significantly reduced in the alcohol-treated guinea pigs. But it was reversed to normal level in the ascorbic acid-supplemented group. The anti-fibrotic action of ascorbic acid in the rapid regression of alcoholic liver fibrosis may be attributed to decrease in the oxidative stress, hepatic stellate cells activation, cytotoxicity and mRNA expression of fibrotic genes CYP2E1, TGF-β(1), TNF-α and α(1) (I) collagen in hepatic tissues. PMID:22149461

  7. Assessment of the chemical changes induced in human melanoma cells by boric acid treatment using infrared imaging

    SciTech Connect

    Acerbo, A.; Miller, L.

    2009-07-01

    Boron is found in everyday foods and drinking water in trace quantities. Boron exists as boric acid (BA) within plants and animals, where low levels have been linked to cancer incidence. However, this correlation is not well characterized. In this study, we examined the chemical and morphological effects of BA on human skin melanoma cells (SK-MEL28) using Fourier Transform InfraRed Imaging (FTIRI) with a Focal Plane Array (FPA) detector. Cells were grown under concentrations of BA ranging from 0 to 50 mM. Cell viability was determined after 1, 2, 3, 5, 7 and 10 days using trypan blue staining. With FTIRI, images of approximately twenty cells per time point per condition were collected. Principal components analysis (PCA) was used to evaluate changes in cell composition, with particular focus on the lipid, protein, and nucleic acid spectral components. Results from trypan blue staining revealed decreased cell viability as BA concentration increased. FTIRI data indicated that the protein and lipid contents (as indicated by the lipid/protein ratio) did not undergo substantial changes due to BA treatment. In contrast, the nucleic acid/protein ratio significantly decreased with BA treatment. PCA results showed an increase in {beta}-sheet protein at higher concentrations of BA (12.5, 25, and 50 mM). Together, these results suggest that high concentrations of BA have an anti-proliferative effect and show signs consistent with apoptosis.

  8. Induced Differentiation of Human Myeloid Leukemia Cells into M2 Macrophages by Combined Treatment with Retinoic Acid and 1α,25-Dihydroxyvitamin D3

    PubMed Central

    Takahashi, Hiromichi; Hatta, Yoshihiro; Iriyama, Noriyoshi; Hasegawa, Yuichiro; Uchida, Hikaru; Nakagawa, Masaru; Makishima, Makoto; Takeuchi, Jin; Takei, Masami

    2014-01-01

    Retinoids and 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) induce differentiation of myeloid leukemia cells into granulocyte and macrophage lineages, respectively. All-trans retinoic acid (ATRA), which is effective in the treatment of acute promyelocytic leukemia, can induce differentiation of other types of myeloid leukemia cells, and combined treatment with retinoid and 1,25(OH)2D3 effectively enhances the differentiation of leukemia cells into macrophage-like cells. Recent work has classified macrophages into M1 and M2 types. In this study, we investigated the effect of combined treatment with retinoid and 1,25(OH)2D3 on differentiation of myeloid leukemia THP-1 and HL60 cells. 9-cis Retinoic acid (9cRA) plus 1,25(OH)2D3 inhibited proliferation of THP-1 and HL60 cells and increased myeloid differentiation markers including nitroblue tetrazolium reducing activity and expression of CD14 and CD11b. ATRA and the synthetic retinoic acid receptor agonist Am80 exhibited similar effects in combination with 1,25(OH)2D3 but less effectively than 9cRA, while the retinoid X receptor agonist HX630 was not effective. 9cRA plus 1,25(OH)2D3 effectively increased expression of M2 macrophage marker genes, such as CD163, ARG1 and IL10, increased surface CD163 expression, and induced interleukin-10 secretion in myeloid leukemia cells, while 9cRA alone had weaker effects on these phenotypes and 1,25(OH)2D3 was not effective. Taken together, our results demonstrate selective induction of M2 macrophage markers in human myeloid leukemia cells by combined treatment with 9cRA and 1,25(OH)2D3. PMID:25409436

  9. Morphologic Damage of Rat Alveolar Epithelial Type II Cells Induced by Bile Acids Could Be Ameliorated by Farnesoid X Receptor Inhibitor Z-Guggulsterone In Vitro

    PubMed Central

    Huang, Yaowei; Hou, Xusheng; Wu, Wenyu; Nie, Lei; Tian, Yinghong; Lu, Yanmeng

    2016-01-01

    Objective. To determine whether bile acids (BAs) affect respiratory functions through the farnesoid X receptor (FXR) expressed in the lungs and to explore the possible mechanisms of BAs-induced respiratory disorder. Methods. Primary cultured alveolar epithelial type II cells (AECIIs) of rat were treated with different concentrations of chenodeoxycholic acid (CDCA) in the presence or absence of FXR inhibitor Z-guggulsterone (GS). Then, expression of FXR in nuclei of AECIIs was assessed by immunofluorescence microscopy. And ultrastructural changes of the cells were observed under transmission electron microscope and analyzed by Image-Pro Plus software. Results. Morphologic damage of AECIIs was exhibited in high BAs group in vitro, with high-level expression of FXR, while FXR inhibitor GS could attenuate the cytotoxicity of BAs to AECIIs. Conclusions. FXR expression was related to the morphologic damage of AECIIs induced by BAs, thus influencing respiratory functions. PMID:27340672

  10. The Cytolytic Amphipathic β(2,2)-Amino Acid LTX-401 Induces DAMP Release in Melanoma Cells and Causes Complete Regression of B16 Melanoma

    PubMed Central

    Eike, Liv-Marie; Mauseth, Brynjar; Camilio, Ketil André; Rekdal, Øystein; Sveinbjørnsson, Baldur

    2016-01-01

    In the present study we examined the ability of the amino acid derivative LTX-401 to induce cell death in cancer cell lines, as well as the capacity to induce regression in a murine melanoma model. Mode of action studies in vitro revealed lytic cell death and release of danger-associated molecular pattern molecules, preceded by massive cytoplasmic vacuolization and compromised lysosomes in treated cells. The use of a murine melanoma model demonstrated that the majority of animals treated with intratumoural injections of LTX-401 showed complete and long-lasting remission. Taken together, these results demonstrate the potential of LTX-401 as an immunotherapeutic agent for the treatment of solid tumors. PMID:26881822

  11. Inhibition of phosphotidylinositol-3 kinase pathway by a novel naphthol derivative of betulinic acid induces cell cycle arrest and apoptosis in cancer cells of different origin

    PubMed Central

    Majeed, R; Hamid, A; Sangwan, P L; Chinthakindi, P K; Koul, S; Rayees, S; Singh, G; Mondhe, D M; Mintoo, M J; Singh, S K; Rath, S K; Saxena, A K

    2014-01-01

    Betulinic acid (BA) is a pentacyclic triterpenoid natural product reported to inhibit cell growth in a variety of cancers. However, the further clinical development of BA got hampered because of poor solubility and pharmacological properties. Interestingly, this molecule offer several hotspots for structural modifications in order to address its associated issues. In our endeavor, we selected C-3 position for the desirable chemical modification in order to improve its cytotoxic and pharmacological potential and prepared a library of different triazoline derivatives of BA. Among them, we previously reported the identification of a potential molecule, that is, 3{1N(5-hydroxy-naphth-1yl)-1H-1,2,3-triazol-4yl}methyloxy betulinic acid (HBA) with significant inhibition of cancer cell growth and their properties. In the present study, we have shown for the first time that HBA decreased the expression of phosphotidylinositol-3 kinase (PI3K) p110α and p85α and caused significant downregulation of pAKT and of NFκB using human leukemia and breast cancer cells as in vitro models. Further it was revealed that PI3K inhibition by HBA induced cell cycle arrest via effects on different cell cycle regulatory proteins that include CDKis cyclins and pGSK3β. Also, this target-specific inhibition was associated with mitochondrial apoptosis as was reflected by the increased expression of mitochondrial bax, downregulated bcl2 and decreased mitochondrial levels of cytochrome c, together with reactive oxygen species generation and decline in mitochondrial membrane potential. The apoptotic effectors such as caspase 8, caspase 9 and caspase 3 were found to be upregulated besides DNA repair-associated enzyme, that is, PARP cleavage caused cancer cell death. Pharmacodynamic evaluation revealed that both HBA and BA were safe upto the dose of 2000 mg/kg body weight and with acceptable pharmacodynamic parameters. The in vitro data corroborated with in vivo anticancer activity wherein Ehrlich

  12. Carnosic acid attenuates apoptosis induced by amyloid-β 1-42 or 1-43 in SH-SY5Y human neuroblastoma cells.

    PubMed

    Meng, Pengfei; Yoshida, Hidemi; Tanji, Kunikazu; Matsumiya, Tomoh; Xing, Fei; Hayakari, Ryo; Wang, Liang; Tsuruga, Kazushi; Tanaka, Hiroshi; Mimura, Junsei; Kosaka, Kunio; Itoh, Ken; Takahashi, Ippei; Kawaguchi, Shogo; Imaizumi, Tadaatsu

    2015-05-01

    Amyloid-beta (Aβ) peptides, Aβ 1-42 (Aβ42) and Aβ43 in particular, cause neurotoxicity and cell death in the brain of Alzheimer's disease (AD) at higher concentrations. Carnosic acid (CA), a phenolic diterpene compound in the labiate herbs rosemary and sage, serves as an activator for neuroprotective and neurotrophic functions in brain cells. We investigated the effect of CA on apoptosis induced by Aβ42 or Aβ43 in cultured SH-SY5Y human neuroblastoma cells. Treatment of the cells with Aβ42 or Aβ43 (monomer, 10 μM each) induced apoptosis, which was confirmed by the cleavage of poly-(ADP-ribose) polymerase (PARP) and apoptosis-inducing factor (AIF). Concurrently, the Aβ treatment induced the activation of caspase (Casp) cascades including an effector Casp (Casp3) and initiator Casps (Casp4, Casp8 and Casp9). Pretreatment of the cells with CA (10 μM) partially attenuated the apoptosis induced by Aβ42 or Aβ43. CA pretreatment also reduced the cellular oligomers of Aβ42 and Aβ43. These results suggest that CA suppressed the activation of Casp cascades by reducing the intracellular oligomerization of exogenous Aβ42/43 monomer. The ingestion of an adequate amount of CA may have a potential in the prevention of Aβ-mediated diseases, particularly AD. PMID:25510380

  13. Docetaxel loaded oleic acid-coated hydroxyapatite nanoparticles enhance the docetaxel-induced apoptosis through activation of caspase-2 in androgen independent prostate cancer cells.

    PubMed

    Luo, Yun; Ling, You; Guo, Wusheng; Pang, Jun; Liu, Weipeng; Fang, Youqiang; Wen, Xinqiao; Wei, Kun; Gao, Xin

    2010-10-15

    Docetaxel (Dtxl) remains the preferred choice of improving the survival of patients with hormone refractory prostate cancer (HRPC), but many patients suffer from modest drug response and significant toxicity. In the present study, we investigated the efficiency of novel Dtxl loaded-[1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-carboxy(polyethylene glycol)]2000 (DSPE-PEG-COOH) stabilized-oleic acid (OA) coated hydroxyapatite (HA) nanoparticles (Dtxl-NPs) and gained insights into the molecular mechanism of the apoptosis induced by these novel Dtxl-loaded nanoparticles. The drug encapsulation efficiency of Dtxl was 83.6% and the sustained drug release was observed over 30days. The Dtxl-NPs exhibited significantly more cytotoxicity in both prostate cancer cell lines (PC3 and DU145) compared with Dtxl in vitro and increased the Dtxl-induced apoptosis in the PC3 cells. Cell cycle analysis showed that the PC3 cells treated with Dtxl-NPs exhibited significant arrest in the G2-M phase but a higher sub-G(0)/G(1) population when compared with Dtxl. The enhanced apoptosis induced by Dtxl-NPs in the PC3 cells was associated with the changes in mitochondrial membrane potential (MMP) and seemed to involve the activation of caspase-2. The kinetic studies of caspases demonstrated an early activation of caspase-2 in Dtxl-NPs-induced apoptosis in PC3 cells, which differs from Dtxl-induced apoptosis. The inhibition of caspase-2 activation by small interfering RNA (siRNA) knockdown resulted in the significant inhibition of Dtxl-NPs-induced disruption of MMP and Dtxl-NPs-induced apoptosis, indicating that the activation of caspase-2 was the critical event before the mitochondrial depolarization in the PC3 cells. Our findings showed that nanoparticles, more than simple drug carriers, may play an active role in mediating the biological effects. PMID:20655966

  14. Eicosapentaenoic acid (EPA) induced apoptosis in HepG2 cells through ROS–Ca{sup 2+}–JNK mitochondrial pathways

    SciTech Connect

    Zhang, Yuanyuan; Han, Lirong; Qi, Wentao; Cheng, Dai; Ma, Xiaolei; Hou, Lihua; Cao, Xiaohong; Wang, Chunling

    2015-01-24

    Highlights: • EPA evoked ROS formation, [Ca{sup 2+}]{sub c} accumulation, the opening of MPTP and the phosphorylation of JNK. • EPA-induced [Ca{sup 2+}]{sub c} elevation was depended on production of ROS. • EPA-induced ROS generation, [Ca{sup 2+}]{sub c} increase, and JNK activated caused MPTP opening. • The apoptosis induced by EPA was related to release of cytochrome C through the MPTP. • EPA induced HepG2 cells apoptosis through ROS–Ca{sup 2+}–JNK mitochondrial pathways. - Abstract: Eicosapentaenoic acid (EPA), a well-known dietary n−3 PUFAS, has been considered to inhibit proliferation of tumor cells. However, the molecular mechanism related to EPA-induced liver cancer cells apoptosis has not been reported. In this study, we investigated the effect of EPA on HepG2 cells proliferation and apoptosis mechanism through mitochondrial pathways. EPA inhibited proliferation of HepG2 cells in a dose-dependent manner and had no significant effect on the cell viability of humor normal liver L-02 cells. It was found that EPA initially evoked ROS formation, leading to [Ca{sup 2+}]{sub c} accumulation and the mitochondrial permeability transition pore (MPTP) opening; EPA-induced HepG2 cells apoptosis was inhibited by N-acetylcysteine (NAC, an inhibitor of ROS), 1,2-bis (2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM, a chelator of calcium) and CsA (inhibitor of MPTP). The relationship between ROS production, the increase of cytoplasmic Ca and MPTP opening was detected. It seems that ROS may act as an upstream regulator of EPA-induced [Ca{sup 2+}]{sub c} generation, moreover, generation of ROS, overload of mitochondrial [Ca{sup 2+}]{sub c}, and JNK activated cause the opening of MPTP. Western blotting results showed that EPA elevated the phosphorylation status of JNK, processes associated with the ROS generation. Simultaneously, the apoptosis induced by EPA was related to release of cytochrome C from mitochondria to cytoplasm through the MPTP

  15. Nucleotide excision repair deficiency increases levels of acrolein-derived cyclic DNA adduct and sensitizes cells to apoptosis induced by docosahexaenoic acid and acrolein.

    PubMed

    Pan, Jishen; Sinclair, Elizabeth; Xuan, Zhuoli; Dyba, Marcin; Fu, Ying; Sen, Supti; Berry, Deborah; Creswell, Karen; Hu, Jiaxi; Roy, Rabindra; Chung, Fung-Lung

    2016-07-01

    The acrolein derived cyclic 1,N(2)-propanodeoxyguanosine adduct (Acr-dG), formed primarily from ω-3 polyunsaturated fatty acids such as docosahexaenoic acid (DHA) under oxidative conditions, while proven to be mutagenic, is potentially involved in DHA-induced apoptosis. The latter may contribute to the chemopreventive effects of DHA. Previous studies have shown that the levels of Acr-dG are correlated with apoptosis induction in HT29 cells treated with DHA. Because Acr-dG is shown to be repaired by the nucleotide excision repair (NER) pathway, to further investigate the role of Acr-dG in apoptosis, in this study, NER-deficient XPA and its isogenic NER-proficient XAN1 cells were treated with DHA. The Acr-dG levels and apoptosis were sharply increased in XPA cells, but not in XAN1 cells when treated with 125μM of DHA. Because DHA can induce formation of various DNA damage, to specifically investigate the role of Acr-dG in apoptosis induction, we treated XPA knockdown HCT116+ch3 cells with acrolein. The levels of both Acr-dG and apoptosis induction increased significantly in the XPA knockdown cells. These results clearly demonstrate that NER deficiency induces higher levels of Acr-dG in cells treated with DHA or acrolein and sensitizes cells to undergo apoptosis in a correlative manner. Collectively, these results support that Acr-dG, a ubiquitously formed mutagenic oxidative DNA adduct, plays a role in DHA-induced apoptosis and suggest that it could serve as a biomarker for the cancer preventive effects of DHA. PMID:27036235

  16. Early apoptotic features of K562 cell death induced by 5-aminolaevulinic acid-based photodynamic therapy.

    PubMed

    Kuzelová, K; Grebenová, D; Pluskalová, M; Marinov, I; Hrkal, Z

    2004-01-23

    5-Aminolaevulinic acid-based photodynamic therapy (ALA-PDT) is used to eliminate cancerous cells through photoactivation of endogenously formed protoporphyrin IX (PPIX) following the administration of PPIX precursor, 5-aminolaevulinic acid (ALA). We report on the kinetics of PPIX accumulation and the mechanism of cytotoxic effects of ALA-PDT studied in the chronic myelogenous leukaemia derived cell line K562. The PPIX distribution and, consequently, cytotoxic effects were found to be heterogenous. A subpopulation of K562 cells accumulating PPIX to a lesser extent exhibits only transient cell cycle arrest. A fraction of cells, probably those with higher PPIX accumulation, are irreversibly damaged by ALA-PDT. We detected several signs of an early apoptosis: lowering of Bcl-xL expression, decrease of the mitochondrial and plasma membrane potential, the cytochrome c release into the cytoplasm, and the unmasking of the mitochondrial antigen 7A6. However, late apoptotic events were lacking: neither caspase-3 activation nor DNA fragmentation occurred. Instead, rapidly progressing cell necrosis resulting from plasma membrane damage was observed. We suggest that the high level of the antiapoptotic heat-shock proteins HSP70 and HSP27 found by us in the K562 cells is responsible for the inhibition of the apoptotic process upstream of caspases activation. PMID:14732253

  17. Long chain n-3 polyunsaturated fatty acids increase the efficacy of docetaxel in mammary cancer cells by downregulating Akt and PKCε/δ-induced ERK pathways.

    PubMed

    Chauvin, Lucie; Goupille, Caroline; Blanc, Charly; Pinault, Michelle; Domingo, Isabelle; Guimaraes, Cyrille; Bougnoux, Philippe; Chevalier, Stephan; Mahéo, Karine

    2016-04-01

    Taxanes can induce drug resistance by increasing signaling pathways such as PI3K/Akt and ERK, which promote survival and cell growth in human cancer cells. We have previously shown that long chain n-3 polyunsaturated fatty acids, such as docosahexaenoic acid (DHA, 22:6n-3) decrease resistance of experimental mammary tumors to anticancer drugs. Our objective was to determine whether DHA could increase tumor sensitivity to docetaxel by down-regulating these survival pathways. In docetaxel-treated MDA-MB-231 cells, phosphorylated-ERK1/2 levels were increased by 60% in membrane and nuclear compartments, compared to untreated cells. Our data showed that ERK1/2 activation depended on PKC activation since: i) enzastaurin (a pan-PKC inhibitor) blocked docetaxel-induced ERK1/2 phosphorylation ii) docetaxel increased PKC activity by 30% and phosphatidic acid level by 1.6-fold iii) inhibition of PKCε and PKCδ by siRNA resulted in reduced phosphorylated ERK1/2 levels. In DHA-supplemented cells, docetaxel was unable to increase PKCε and δ levels in membrane and nuclear fractions, resulting in diminished ERK1/2 phosphorylation and increased docetaxel efficacy. Reduced membrane level of PKCε and PKCδ was associated with significant incorporation of DHA in all phospholipids, including phosphatidylcholine which is a major source of phosphatidic acid. Additionally, examination of the Akt pathway showed that DHA could repress docetaxel-induced Ser473Akt phosphorylation. In rat mammary tumors, dietary DHA supplementation during docetaxel chemotherapy repressed ERK and Akt survival pathways and in turn strongly improved taxane efficacy. The P-ERK level was negatively correlated with tumor regression. These findings are of potential clinical importance in treating chemotherapy-refractory cancer. PMID:26821209

  18. Analysis of DNA strand breaks induced in rodent liver in vivo, hepatocytes in primary culture, and a human cell line by chlorinated acetic acids and chlorinated acetaldehydes

    SciTech Connect

    Chang, L.W.; Daniel, F.B. ); DeAngelo, A.B. )

    1992-01-01

    An alkaline unwinding assay was used to quantitate the induction of DNA strand breaks (DNA SB) in the livers of rats and mice treated in vivo, in rodent hepatocytes in primary culture, and in CCRF-CEM cells, a human lymphoblastic leukemia cell line, following treatment with tri-(TCA), di-(CA), and mono-(MCA) chloroacetic acid and their corresponding aldehydes, tri-(chloralhydrate, CH), di(DCAA) and mono-(CAA) chloroacetaldehyde. None of the chloracetic acids induced DNA SB in the livers of rats at 4 hr following a single administration of 1-10 mmole/kg. TCA (10 mmole/kg) and DCA (5 and 10 mmole/kg) did produce a small amount of strand breakage in mice (7% at 4hr) but not at 1 hr. N-nitrosodiethylamine (DENA), an established alkylating agent and a rodent hepatocarcinogen, produced DNA SB in the livers of both species. TCA, DCA, and MCA also failed to induce DNA strand breaks in splenocytes and epithelial cells derived from the stomach and duodenum of mice treated in vivo. None of the three chloroacetaldehydes induced DNA SB in either mouse or rat liver. These studies provide further evidence that the chloroacetic acids lack genotoxic activity not only in rodent liver, a tissue in that they induce tumors, but in a variety of other rodent tissues and cultured cell types. Two of the chloroacetaldehydes, DCAA and CAA, are direct acting DNA damaging agents in CCRF-CEM cells, but not in liver or splenocytes in vivo or in cultured hepatocytes. CH showed no activity in any system investigated. 58 refs., 6 figs., 2 tabs.

  19. Inhibition of de novo Palmitate Synthesis by Fatty Acid Synthase Induces Apoptosis in Tumor Cells by Remodeling Cell Membranes, Inhibiting Signaling Pathways, and Reprogramming Gene Expression

    PubMed Central

    Ventura, Richard; Mordec, Kasia; Waszczuk, Joanna; Wang, Zhaoti; Lai, Julie; Fridlib, Marina; Buckley, Douglas; Kemble, George; Heuer, Timothy S.

    2015-01-01

    Inhibition of de novo palmitate synthesis via fatty acid synthase (FASN) inhibition provides an unproven approach to cancer therapy with a strong biological rationale. FASN expression increases with tumor progression and associates with chemoresistance, tumor metastasis, and diminished patient survival in numerous tumor types. TVB-3166, an orally-available, reversible, potent, and selective FASN inhibitor induces apoptosis, inhibits anchorage-independent cell growth under lipid-rich conditions, and inhibits in-vivo xenograft tumor growth. Dose-dependent effects are observed between 20–200 nM TVB-3166, which agrees with the IC50 in biochemical FASN and cellular palmitate synthesis assays. Mechanistic studies show that FASN inhibition disrupts lipid raft architecture, inhibits biological pathways such as lipid biosynthesis, PI3K–AKT–mTOR and β-catenin signal transduction, and inhibits expression of oncogenic effectors such as c-Myc; effects that are tumor-cell specific. Our results demonstrate that FASN inhibition has anti-tumor activities in biologically diverse preclinical tumor models and provide mechanistic and pharmacologic evidence that FASN inhibition presents a promising therapeutic strategy for treating a variety of cancers, including those expressing mutant K-Ras, ErbB2, c-Met, and PTEN. The reported findings inform ongoing studies to link mechanisms of action with defined tumor types and advance the discovery of biomarkers supporting development of FASN inhibitors as cancer therapeutics. Research in context Fatty acid synthase (FASN) is a vital enzyme in tumor cell biology; the over-expression of FASN is associated with diminished patient prognosis and resistance to many cancer therapies. Our data demonstrate that selective and potent FASN inhibition with TVB-3166 leads to selective death of tumor cells, without significant effect on normal cells, and inhibits in vivo xenograft tumor growth at well-tolerated doses. Candidate biomarkers for

  20. All-trans-retinoid acid induces the differentiation of encapsulated mouse embryonic stem cells into GABAergic neurons.

    PubMed

    Addae, Cynthia; Yi, Xiaoping; Gernapudi, Ramkishore; Cheng, Henrique; Musto, Alberto; Martinez-Ceballos, Eduardo

    2012-06-01

    Embryonic stem (ES) cells are pluripotent cells that can differentiate into all three main germ layers: endoderm, mesoderm, and ectoderm. Although a number of methods have been developed to differentiate ES cells into neuronal phenotypes such as sensory and motor neurons, the efficient generation of GABAergic interneurons from ES cells still presents an ongoing challenge. Because the main output of inhibitory GABAergic interneurons is the gamma-aminobutyric-acid (GABA), a neurotransmitter whose controlled homeostasis is required for normal brain function, the efficient generation in culture of functional interneurons may have future implications on the treatment of neurological disorders such as epilepsy, autism, and schizophrenia. The goal of this work was to examine the generation of GABAergic neurons from mouse ES cells by comparing an embryoid body-based methodology versus a hydrogel-based encapsulation protocol that involves the use of all-trans-retinoid acid (RA). We observed that (1) there was a 2-fold increase in neuronal differentiation in encapsulated versus non-encapsulated cells and (2) there was an increase in the specificity for interneuronal differentiation in encapsulated cells, as assessed by mRNA expression and electrophysiology approaches. Furthermore, our results indicate that most of the neurons obtained from encapsulated mouse ES cells are GABA-positive (∼87%). Thus, these results suggest that combining encapsulation of ES cells and RA treatment provide a more efficient and scalable differentiation strategy for the generation in culture of functional GABAergic interneurons. This technology may have implications for future cell replacement therapies and the treatment of CNS disorders. PMID:22466603

  1. All-Trans-Retinoid Acid Induces the Differentiation of Encapsulated Mouse Embryonic Stem Cells into GABAergic Neurons

    PubMed Central

    Addae, Cynthia; Yi, Xiaoping; Gernapudi, Ramkishore; Cheng, Henrique; Musto, Alberto; Martinez-Ceballos, Eduardo

    2012-01-01

    Embryonic stem (ES) cells are pluripotent cells that can differentiate into all three main germ layers: endoderm, mesoderm, and ectoderm. Although a number of methods have been developed to differentiate ES cells into neuronal phenotypes such as sensory and motor neurons, the efficient generation of GABAergic interneurons from ES cells still presents an ongoing challenge. Because the main output of inhibitory GABAergic interneurons is the gamma-aminobutyric-acid (GABA), a neurotransmitter whose controlled homeostasis is required for normal brain function, the efficient generation in culture of functional interneurons may have future implications on the treatment of neurological disorders such as epilepsy, autism, and schizophrenia. The goal of this work was to examine the generation of GABAergic neurons from mouse ES cells by comparing an embryoid body-based methodology versus a hydrogel-based encapsulation protocol that involves the use of all-trans-retinoid acid (RA). We observed that 1) there was a 2-fold increase in neuronal differentiation in encapsulated versus non-encapsulated cells and 2) there was an increase in the specificity for interneuronal differentiation in encapsulated cells, as assessed by mRNA expression and electrophysiology approaches. Furthermore, our results indicate that most of the neurons obtained from encapsulated mouse ES cells are GABA-positive (~87%). Thus, these results suggest that combining encapsulation of ES cells and RA treatment provide a more efficient and scalable differentiation strategy for the generation in culture of functional GABAergic interneurons. This technology may have implications for future cell replacement therapies and the treatment of CNS disorders. PMID:22466603

  2. The E3 ubiquitin protein ligase MDM2 dictates all-trans retinoic acid-induced osteoblastic differentiation of osteosarcoma cells by modulating the degradation of RARα.

    PubMed

    Ying, M; Zhang, L; Zhou, Q; Shao, X; Cao, J; Zhang, N; Li, W; Zhu, H; Yang, B; He, Q

    2016-08-18

    Retinoic acid receptor alpha (RARα) has a critical role in the differentiation process of osteosarcoma cells induced by all-trans retinoic acid (ATRA). However, degradation of RARα through ubiquitin proteasome pathway weakens the differentiation efficiency of osteosarcoma cells. In this study, we discover that murine double minute-2 (MDM2) acts as an E3 ubiquitin ligase to target RARα for degradation. We observe that MDM2 is required for RARα polyubiquitination and proteasomal degradation because downregulation of MDM2 by short hairpin RNA results in the accumulation of RARα, and MDM2 overexpression promotes the degradation of RARα. We also demonstrate that the N-terminal domain of MDM2 (amino acids 1-109) is the major RARα-binding site. Importantly, endogenous MDM2 levels are not only upregulated in human primary osteosarcoma blasts but are also inversely correlated with the level of osteopontin, which is a marker of bone differentiation. Moreover, MDM2 impairs the ATRA-induced osteoblastic differentiation of osteosarcoma cells, whereas an inhibitor of the MDM2 ubiquitin ligase synergizes with ATRA to enhance the differentiation of osteosarcoma cells and primary osteosarcoma blasts. Therefore, our study indicates that MDM2 serves as an E3 ubiquitin ligase to regulate the degradation of RARα and suggests that MDM2 is a novel therapeutic target for ATRA-based differentiation therapeutic approaches in osteosarcoma. PMID:26776160

  3. Yeast Extract and Silver Nitrate Induce the Expression of Phenylpropanoid Biosynthetic Genes and Induce the Accumulation of Rosmarinic Acid in Agastache rugosa Cell Culture.

    PubMed

    Park, Woo Tae; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Yeo, Sun Kyung; Jeon, Jin; Park, Jong Seok; Lee, Sook Young; Park, Sang Un

    2016-01-01

    The present study aimed to investigate the role of yeast extract and silver nitrate on the enhancement of phenylpropanoid pathway genes and accumulation of rosmarinic acid in Agastache rugosa cell cultures. The treatment of cell cultures with yeast extract (500 mg/L) and silver nitrate (30 mg/L) for varying times enhanced the expression of genes in the phenylpropanoid pathway and the production of rosmarinic acid. The results indicated that the expression of RAS and HPPR was proportional to the amount of yeast extract and silver nitrate. The transcript levels of HPPR under yeast extract treatment were 1.84-, 1.97-, and 2.86-fold higher than the control treatments after 3, 6, and 12 h, respectively, whereas PAL expression under silver nitrate treatment was 52.31-fold higher than in the non-treated controls after 24 h of elicitation. The concentration of rosmarinic acid was directly proportional to the concentration of the applied elicitors. Yeast extract supplementation documented the highest amount of rosmarinic acid at 4.98 mg/g, whereas silver nitrate addition resulted in a comparatively lower amount of rosmarinic acid at 0.65 mg/g. In conclusion, addition of yeast extract to the cell cultures enhanced the accumulation of rosmarinic acid, which was evidenced by the expression levels of the phenylpropanoid biosynthetic pathway genes in A. rugosa. PMID:27043507

  4. Maslinic Acid, a Natural Triterpene, Induces a Death Receptor-Mediated Apoptotic Mechanism in Caco-2 p53-Deficient Colon Adenocarcinoma Cells

    PubMed Central

    Reyes-Zurita, Fernando J.; Rufino-Palomares, Eva E.; García-Salguero, Leticia; Peragón, Juan; Medina, Pedro P.; Parra, Andrés; Cascante, Marta; Lupiáñez, José A.

    2016-01-01

    Maslinic acid (MA) is a natural triterpene present in high concentrations in the waxy skin of olives. We have previously reported that MA induces apoptotic cell death via the mitochondrial apoptotic pathway in HT29 colon cancer cells. Here, we show that MA induces apoptosis in Caco-2 colon cancer cells via the extrinsic apoptotic pathway in a dose-dependent manner. MA triggered a series of effects associated with apoptosis, including the cleavage of caspases -8 and -3, and increased the levels of t-Bid within a few hours of its addition to the culture medium. MA had no effect on the expression of the Bax protein, release of cytochrome-c or on the mitochondrial membrane potential. This suggests that MA triggered the extrinsic apoptotic pathway in this cell type, as opposed to the intrinsic pathway found in the HT29 colon-cancer cell line. Our results suggest that the apoptotic mechanism induced in Caco-2 may be different from that found in HT29 colon-cancer cells, and that in Caco-2 cells MA seems to work independently of p53. Natural antitumoral agents capable of activating both the extrinsic and intrinsic apoptotic pathways could be of great use in treating colon-cancer of whatever origin. PMID:26751572

  5. Tamoxifen enhances the differentiation-inducing and growth-inhibitory effects of all-trans retinoic acid in acute promyelocytic leukemia cells.

    PubMed

    Adachi, Koji; Honma, Yoshio; Miyake, Takaaki; Kawakami, Koshi; Takahashi, Tsutomu; Suzumiya, Junji

    2016-03-01

    All-trans retinoic acid (ATRA) is valuable in differentiation therapy for acute promyelocytic leukemia (APL). However, ATRA has had limited success as a single agent, due to the development of resistance. We found that tamoxifen effectively enhanced the differentiation-inducing effect of ATRA. Tamoxifen alone inhibited the proliferation of myeloid leukemia cell lines while only slightly increasing morphologic differentiation. Tamoxifen effectively enhanced the growth-inhibiting actions of various differentiation-inducing agents. ATRA in the presence of tamoxifen increased NBT reduction and the expression of CD11b in HL-60 cells more effectively than ATRA alone. Tamoxifen also enhanced the differentiation induced by the other inducers tested. ATRA induced the differentiation of APL cell lines NB4 and HT93 and APL cells in primary culture, and this differentiation was also enhanced by tamoxifen. Tamoxifen is one of the most widely used drugs for the treatment of cancer and has few side effects. The combination of ATRA and tamoxifen might be considered for the treatment of APL patients in whom it can be difficult to apply arsenic trioxide or anthracyclines. PMID:26797574

  6. Carnosic Acid Prevents Beta-Amyloid-Induced Injury in Human Neuroblastoma SH-SY5Y Cells via the Induction of Autophagy.

    PubMed

    Liu, Jie; Su, Hua; Qu, Qiu-Min

    2016-09-01

    Beta-amyloid (Aβ), the hallmark protein in Alzheimer's disease (AD), induces neurotoxicity that involves oxidative stress and mitochondrial dysfunction, leading to cell death. Carnosic acid (CA), a polyphenolic diterpene isolated from the herb rosemary (Rosemarinus officinalis), was investigated in our study to assess its neuroprotective effect and underlying mechanism against Aβ-induced injury in human neuroblastoma SH-SY5Y cells. We found that CA pretreatment alleviated the Aβ25-35-induced loss of cell viability, inhibited both Aβ1-42 accumulation and tau hyperphosphorylation, reduced reactive oxygen species generation, and maintained the mitochondrial membrane potential. Moreover, CA increased the microtubule-associated protein light chain 3 (LC3)-II/I ratio and decreased SQSTM1(p62), indicating that CA could induce autophagy. Autophagy inhibitor 3-methyladenine (3-MA) attenuated the neuroprotective effect of CA, suggesting that autophagy was involved in the neuroprotection of CA. It was also observed that CA activated AMP-activated protein kinase (AMPK) but inhibited mammalian target of rapamycin (mTOR). Furthermore, blocking AMPK with si-AMPKα successfully inhibited the upregulation of LC3-II/I, prevented the downregulation of phosphorylation of mTOR and SQSTM1(p62), indicating that CA induced autophagy in SH-SY5Y cells via the activation of AMPK. These results suggested that CA might be a potential agent for preventing AD. PMID:27168327

  7. Glycyrrhizic acid-mediated subdual of myeloid-derived suppressor cells induces antileishmanial immune responses in a susceptible host.

    PubMed

    Bandyopadhyay, Syamdas; Bhattacharjee, Amrita; Banerjee, Sayantan; Halder, Kuntal; Das, Shibali; Paul Chowdhury, Bidisha; Majumdar, Subrata

    2015-12-01

    CD11b(+) Gr1(+) myeloid-derived suppressor cells (MDSCs), a heterogeneous population of precursor cells, modulate protective immunity against visceral leishmaniasis by suppressing T cell functions. We observed that CD11b(+) Gr1(+) MDSCs, which initially expanded in soluble leishmanial antigen (SLA)-immunized mice and later diminished, suppressed proliferation of T cells isolated from SLA-immunized mice, but to a lesser extent than the case in naive mice. This lesser suppression of MDSCs accompanied the expression of F4/80 and the production of Cox-2, arginase I, nitric oxide, and PGE2. However, with SLA immunization, there was no difference in the expression of interleukin-2 (IL-2) or gamma interferon (IFN-γ) by T cells, in contrast to the case in nonimmunized mice, in which there is an influence. Glycyrrhizic acid (a triterpenoid compound)-mediated inhibition of Cox-2 in myeloid-derived suppressor cells influenced the capacity of T cells to proliferate and the expression of IL-2 and IFN-γ in Leishmania donovani-infected BALB/c mice. Further characterization confirmed that administration of glycyrrhizic acid to L. donovani-infected BALB/c mice results in an impairment of the generation of MDSCs and a reciprocal organ-specific proliferation of IFN-γ- and IL-10-expressing CD4(+) and CD8(+) T cells. Comprehensive knowledge on the Cox-2-mediated regulation of myeloid-derived suppressor cells might be involved in unlocking a new avenue for therapeutic interventions during visceral leishmaniasis. PMID:26351281

  8. FABP3 and brown adipocyte-characteristic mitochondrial fatty acid oxidation enzymes are induced in beige cells in a different pathway from UCP1.

    PubMed

    Nakamura, Yuki; Sato, Takahiro; Shiimura, Yuki; Miura, Yoshiki; Kojima, Masayasu

    2013-11-01

    Cold exposure and β3-adrenergic receptor agonist (CL316,243) treatment induce the production of beige cells, which express brown adipocytes(BA)-specific UCP1 protein, in white adipose tissue (WAT). It remains unclear whether the beige cells, which have different gene expression patterns from BA, express BA-characteristic fatty acid oxidation (FAO) proteins. Here we found that 5 day cold exposure and CL316,243 treatment of WAT, but not CL316,243 treatment of primary adipocytes of C57BL/6J mice, increased mRNA levels of BA-characteristic FAO proteins. These results suggest that BA-characteristic FAO proteins are induced in beige cells in a different pathway from UCP1. PMID:24129192

  9. c-Myc-mediated expression of nucleophosmin/B23 decreases during retinoic acid-induced differentiation of human leukemia HL-60 cells.

    PubMed

    Yung, Benjamin Y M

    2004-12-17

    The retinoic acid-induced differentiation of human leukemia HL-60 cells towards mature granulocytic cells was accompanied by the decline in the protein levels of c-myc, nucleophosmin/B23 and its promoter activity. These RA-induced effects were further enhanced by the concurrent treatment of HL-60 cells with p38 map kinase inhibitor SB203580 (SB). It seems that there is a strong correlation of nucleophosmin/B23 and c-Myc expressions in cells under RA treatment. Furthermore, nucleophosmin/B23 promoter activity decreased upon c-Myc antisense-mediated reduction of intracellular amount of c-Myc. CHIP assays showed that binding of c-Myc to the nucleophosmin/B23 promoter decreased in RA-treated cells. Thus, nucleophosmin/B23 expression is targeted by c-Myc during RA-induced differentiation. These results provide evidence for a novel mechanism of transcriptional downregulation of nucleophosmin/B23 and the functional role of c-Myc in RA-induced differentiation. PMID:15589822

  10. 11-Keto-boswellic acid derived amides and monodesmosidic saponins induce apoptosis in breast and cervical cancers cells.

    PubMed

    Csuk, René; Barthel-Niesen, Anja; Barthel, Alexander; Schäfer, Renate; Al-Harrasi, Ahmed

    2015-07-15

    Beta-boswellic acids are considered the main bioactive components of frankincense. Their potential to act as cytotoxic agents, as well as that of their derivatives remained unexploited so far. In this study we were able to prepare derivatives of 11-keto-β-boswellic acid (KBA) that showed lower IC50 values as determined by a sulphorhodamine B (SRB) assay using several different human tumour cell lines. Monodesmosidic saponins of KBA are as cytotoxic as 3-acetyl-KBA. The presence of a free hydroxyl group at position C-3 seems to lower cytotoxicity while the presence of an amide function at C-24 improves cytotoxicity. The most active compound of this series gave IC50 values as low as 4.5 μM. Cell death proceeded mainly via apoptosis. PMID:26073487

  11. Atomic evidence that modification of H-bonds established with amino acids critical for host-cell binding induces sterile immunity against malaria

    SciTech Connect

    Patarroyo, Manuel E.; Cifuentes, Gladys; Pirajan, Camilo; Moreno-Vranich, Armando; Vanegas, Magnolia

    2010-04-09

    Based on the 3D X-ray crystallographic structures of relevant proteins of the malaria parasite involved in invasion to host cells and 3D NMR structures of High Activity Binding Peptides (HABPs) and their respective analogues, it was found that HABPs are rendered into highly immunogenic and sterile immunity inducers in the Aotus experimental model by modifying those amino acids that establish H-bonds with other HABPs or binding to host's cells. This finding adds striking and novel physicochemical principles, at the atomic level, for a logical and rational vaccine development methodology against infectious disease, among them malaria.

  12. Involvement of membrane-type bile acid receptor M-BAR/TGR5 in bile acid-induced activation of epidermal growth factor receptor and mitogen-activated protein kinases in gastric carcinoma cells

    SciTech Connect

    Yasuda, Hiroshi . E-mail: hiroshi-yasuda@showa-university-fujigaoka.gr.jp; Hirata, Shuko; Inoue, Kazuaki; Mashima, Hirosato; Ohnishi, Hirohide; Yoshiba, Makoto

    2007-03-02

    Bile acids, which have been implicated in gastrointestinal-tract cell carcinogenesis, share properties with tumor promoters in that both affect signal transduction pathways responsible for cell proliferation and apoptosis. In the present study, we demonstrate that EGFR-ERK1/2 is activated following treatment of AGS human gastric carcinoma cells with bile acids. EGFR phosphoactivation is ligand-dependent, since treatment of cells with HB-EGF antisera or CM197 (a selective inhibitor of HB-EGF) markedly inhibits deoxycholate (DC)-promoted activation. Membrane-type bile acid receptor (M-BAR)/TGR5 is a recently identified G-protein-coupled receptor (GPCR). In AGS cells, siRNAs that target M-BAR suppress DC-induced phosphorylation of EGFR. Furthermore, introduction of siRNAs targeting ADAM17 transcripts resulted in suppression of DC-induced activation of EGFR and ERK1/2. These results suggest that in AGS cells, DC transactivates EGFR through M-BAR- and ADAM/HB-EGF-dependent mechanisms.

  13. MEMANTINE ATTENUATES THE OKADAIC ACID INDUCED SHORT-TERM SPATIAL MEMORY IMPAIRMENT AND HIPPOCAMPAL CELL LOSS IN RATS.

    PubMed

    Dashniani, M; Chighladze, M; Burjanadze, M; Beselia, G; Kruashvili, L

    2016-03-01

    In the present study, the possible beneficial effect of memantine on the Okadaic Acid (OA) induced spatial short-term memory impairment was examined in spatial alternation task, and the neuroprotective potential of memantine on OA-induced structural changes in the hippocampus was evaluated by Nissl staining. OA was dissolved in artificial cerebrospinal fluid (aCSF) and injected intracerebroventriculary (ICV) 200 ng in a volume of 10 μl bilaterally. Vehicle control received aCSF ICV bilaterally. Control and OA injected rats were divided into 2 subgroups injected i.p. with saline or memantine (5 mg/kg). Memantine or saline were given daily for 13 days starting from the day of OA injection. Behavioral study showed that bilateral ICV microinjection of OA induced impairment in spatial short-term memory. Nissl staining in the present study showed that the ICV microinjection of OA significantly decreased the number of surviving pyramidal neurons in the CA1 region of the hippocampus. Chronic administration of memantine effectively attenuated OA induced spatial short-term memory impairment and the OA-induced neuropathological changes in the hippocampus. Therefore, ICV injection of OA can be used as an experimental model to study mechanisms of neurodegeneration and define novel therapeutics targets for AD pathology. PMID:27119837

  14. Effect of dietary fibers on cholic acid induced cell proliferation in the colonic epithelium of C57BL/6J mice

    SciTech Connect

    Robblee, N.M.; Bruce, W.R.; Bird, R.P.

    1986-03-01

    It has been postulated that high fat diets promote tumorigenesis by increasing the level of secondary bile acids in the colonic lumen. Dietary fibers are thought to be protective perhaps through their interaction with bile acids. In the present study, animals were fed diets containing either 0%, 5%, or 10% cellulose (C), pectin (P), or wheat bran (WB). The diets were formulated to contain either 0% (control) or 0.2% cholic acid (test). After two weeks of dietary treatment the animals were injected with (/sup 3/H)-thymidine and their colons were processed for autoradiography. The number of labeled cells (LC) in the colonic crypts was determined. Among the control diets, 10%P induced a two-fold increase in the LC. All the test groups had significantly higher LC than in their controls. However, the C group excited a higher LC than the P or WB groups (5.2 +/- 0.8 vs 3.9 +/- 0.8 or 3.9 +/- 0.6). These results were substantiated by metaphase arrest technique. The authors results show that nonfermentable fiber does not alleviate bile acid induced cell proliferative activity in the colon whereas fermentable fibers will counteract the promotional effect of a high fat diet.

  15. The combination of the antiestrogen endoxifen with all-trans-retinoic acid has anti-proliferative and anti-migration effects on melanoma cells without inducing significant toxicity in non-neoplasic cells.

    PubMed

    Ribeiro, Mariana P C; Silva, Filomena S G; Paixão, Joana; Santos, Armanda E; Custódio, José B A

    2013-09-01

    Melanoma incidence is dramatically increasing and the available treatments beyond partial efficacy have severe side effects. Retinoids are promising anticancer agents, but their clinical use has been limited by their toxicity, although a combination with other agents can possibly generate a therapeutic action at lower dosage. Thus, we investigated the effects of all-trans-retinoic acid combined with the antiestrogen endoxifen on melanoma cell proliferation and the effects were compared with its pro-drug tamoxifen. Moreover, we evaluated the effects of these combinations on non-neoplasic cells and assessed mitochondrial bioenergetic functions, to predict their potential toxicity. Individually, all-trans-retinoic acid and the antiestrogens endoxifen and tamoxifen decreased melanoma cell biomass, cell viability and DNA synthesis, without increased cell death, suggesting that the compounds inhibited cell proliferation. Noteworthy, endoxifen decreased cell proliferation more efficiently than tamoxifen. The combination of endoxifen with all-trans-retinoic acid enhanced the antiproliferative effects of the compounds individually more potently than tamoxifen, which did not enhance the effects induced by all-trans-retinoic acid alone, and blocked cell cycle progression in G1. Moreover, the combination of all-trans-retinoic acid with endoxifen significantly decreased melanoma cells migration, whereas the combination with tamoxifen did not present significant effects. At the concentrations used the compounds did not induce cytotoxicity in non-neoplasic cells and liver mitochondrial bioenergetic function was not affected. Altogether, our results show for the first time that a combined treatment of all-trans-retinoic acid with endoxifen may provide an anti-proliferative and anti-migration effect upon melanoma cells without major toxicity, offering a powerful therapeutic strategy for malignant melanoma. PMID:23712006

  16. Inducing cell cycle arrest and apoptosis by dimercaptosuccinic acid modified Fe3O4 magnetic nanoparticles combined with nontoxic concentration of bortezomib and gambogic acid in RPMI-8226 cells

    PubMed Central

    Zhang, Wei; Qiao, Lixing; Wang, Xinchao; Senthilkumar, Ravichandran; Wang, Fei; Chen, Baoan

    2015-01-01

    The purpose of this study was to determine the potential benefits of combination therapy using dimercaptosuccinic acid modified iron oxide (DMSA-Fe3O4) magnetic nanoparticles (MNPs) combined with nontoxic concentration of bortezomib (BTZ) and gambogic acid (GA) on multiple myeloma (MM) RPMI-8226 cells and possible underlying mechanisms. The effects of BTZ-GA-loaded MNP-Fe3O4 (BTZ-GA/MNPs) on cell proliferation were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,4,-diphenyltetrazolium bromide (MTT) method. Cell cycle and apoptosis were detected using the terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) assay and flow cytometry (FCM). Furthermore, DMSA-Fe3O4 MNPs were characterized in terms of distribution, apoptotic morphology, and cellular uptake by transmission electron microscopy (TEM) and 4,6-diamidino-2-phenylindole (DAPI) staining. Subsequently, the effect of BTZ-GA/MNPs combination on PI3K/Akt activation and apoptotic-related protein were appraised by Western blotting. MTT assay and hematoxylin and eosin (HE) staining were applied to elevate the functions of BTZ-GA/MNPs combination on the tumor xenograft model and tumor necrosis. The results of this study revealed that the majority of MNPs were quasi-spherical and the MNPs taken up by cells were located in the endosome vesicles of cytoplasm. Nontoxic concentration of BTZ-GA/MNPs increased G2/M phase cell cycle arrest and induced apoptosis in RPMI-8226 cells. Furthermore, the combination of BTZ-GA/MNPs activated phosphorylated Akt levels, Caspase-3, and Bax expression, and down-regulated the PI3K and Bcl-2 levels significantly. Meanwhile, the in vivo tumor xenograft model indicated that the treatment of BTZ-GA/MNPs decreased the tumor growth and volume and induced cell apoptosis and necrosis. These findings suggest that chemotherapeutic agents polymerized MNPs-Fe3O4 with GA could serve as a better alternative for targeted therapeutic approaches to treat multiple

  17. ERKs and mitochondria-related pathways are essential for glycyrrhizic acid-mediated neuroprotection against glutamate-induced toxicity in differentiated PC12 cells

    PubMed Central

    Wang, D.; Guo, T.Q.; Wang, Z.Y.; Lu, J.H.; Liu, D.P.; Meng, Q.F.; Xie, J.; Zhang, X.L.; Liu, Y.; Teng, L.S.

    2014-01-01

    The present study focuses on the neuroprotective effect of glycyrrhizic acid (GA, a major compound separated from Glycyrrhiza Radix, which is a crude Chinese traditional drug) against glutamate-induced cytotoxicity in differentiated PC12 (DPC12) cells. The results showed that GA treatment improved cell viability and ameliorated abnormal glutamate-induced alterations in mitochondria in DPC12 cells. GA reversed glutamate-suppressed B-cell lymphoma 2 levels, inhibited glutamate-enhanced expressions of Bax and cleaved caspase 3, and reduced cytochrome C (Cyto C) release. Exposure to glutamate strongly inhibited phosphorylation of AKT (protein kinase B) and extracellular signal-regulated kinases (ERKs); however, GA pretreatment enhanced activation of ERKs but not AKT. The presence of PD98059 (a mitogen-activated protein/extracellular signal-regulated kinase kinase [MEK] inhibitor) but not LY294002 (a phosphoinositide 3-kinase [PI3K] inhibitor) diminished the potency of GA for improving viability of glutamate-exposed DPC12 cells. These results indicated that ERKs and mitochondria-related pathways are essential for the neuroprotective effect of GA against glutamate-induced toxicity in DPC12 cells. The present study provides experimental evidence supporting GA as a potential therapeutic agent for use in the treatment of neurodegenerative diseases. PMID:25075574

  18. An α-acetoxy-tirucallic acid isomer inhibits Akt/mTOR signaling and induces oxidative stress in prostate cancer cells.

    PubMed

    El Gaafary, Menna; Büchele, Berthold; Syrovets, Tatiana; Agnolet, Sara; Schneider, Bernd; Schmidt, Christoph Q; Simmet, Thomas

    2015-01-01

    Here we provide evidence that αATA(8,24) (3α-acetyloxy-tir-8,24-dien-21-oic acid) inhibits Akt/mammalian target of rapamycin (mTOR) signaling. αATA(8,24) and other tirucallic acids were isolated from the acetylated extract of the oleo gum resin of Boswellia serrata to chemical homogeneity. Compared with related tirucallic acids, αATA(8,24) was the most potent inhibitor of the proliferation of androgen-insensitive prostate cancer cells in vitro and in vivo, in prostate cancer xenografted onto chick chorioallantoic membranes. αATA(8,24) induced loss of cell membrane asymmetry, caspase-3 activation, and DNA fragmentation in vitro and in vivo. These effects were selective for cancer cells, because αATA(8,24) exerted no overt toxic effects on peripheral blood mononuclear cells or the chick embryo. At the molecular level, αATA(8,24) inhibited the Akt1 kinase activity. Prior to all biochemical signs of cellular dysfunction, αATA(8,24) induced inhibition of the Akt downstream target mTOR as indicated by dephosphorylation of S6K1. This event was followed by decreased expression of cell cycle regulators, such as cyclin D1, cyclin E, and cyclin B1, as well as cyclin-dependent kinases CDK4 and CDK2 and phosphoretinoblastoma protein, which led to inhibition of the cell-cycle progression. In agreement with the mTOR inhibition, αATA(8,24) and rapamycin increased the volume of acidic vesicular organelles. In contrast to rapamycin, αATA(8,24) destabilized lysosomal and mitochondrial membranes and induced reactive oxygen species production in cancer cells. The ability of αATA(8,24) to inhibit Akt/mTOR signaling and to induce simultaneously oxidative stress could be exploited for the development of novel antitumor therapeutics with a lower profile of toxic side effects. PMID:25316122

  19. Ocotillol, a Majonoside R2 Metabolite, Ameliorates 2,4,6-Trinitrobenzenesulfonic Acid-Induced Colitis in Mice by Restoring the Balance of Th17/Treg Cells.

    PubMed

    Lee, Sang-Yun; Jeong, Jin-Ju; Le, Thi Hong Van; Eun, Su-Hyeon; Nguyen, Minh Duc; Park, Jeong Hill; Kim, Dong-Hyun

    2015-08-12

    In a preliminary experiment, majonoside R2 (MR2), isolated from Vietnamese ginseng (Panax vietnamensis Ha et Grushv.), inhibited differentiation to Th17 cells and was metabolized to ocotillol via pseudoginsenoside RT4 (PRT4) by gut microbiota. Therefore, we examined the inhibitory effects of MR2 and its metabolites PRT4 and ocotillol against Th17 cell differentiation. These ginsenosides significantly suppressed interleukin (IL)-6/tumor growth factor beta-induced differentiation of splenic CD4(+) T cells into Th17 cells and expression of IL-17 in vitro. Among these ginsenosides, ocotillol showed the highest inhibitory effect. We also examined the anti-inflammatory effect of ocotillol in mice with 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. Oral administration of ocotillol significantly suppressed TNBS-induced colon shortening, macroscopic score, myeloperoxidase activity, and production of nitric oxide and prostaglandin E2. Ocotillol treatment increased TNBS-suppressed expression of tight junction proteins ZO-1, occludin, and claudin-1 in the colon. Treatment with ocotillol inhibited TNBS-induced expression of tumor necrosis factor (TNF)-α and IL-1β, as well as activation of NF-κB and MAPKs. Moreover, treatment with ocotillol inhibited TNBS- induced differentiation to Th17 cells in the lamina propria of colon, as well as expression of T-bet, RORγt, IL-17, and IL-23. Ocotillol treatment also increased Treg cell differentiation and Foxp3 and IL-10 expression. These findings suggest that orally administered MR2 may be metabolized to ocotillol in the intestine by gut microbiota and the transformed ocotillol may ameliorate inflammatory diseases such as colitis by restoring the balance of Th17/Treg cells. PMID:26194345

  20. Retinoic acid induces caspase-8 transcription via phospho-CREB and increases apoptotic responses to death stimuli in neuroblastoma cells

    PubMed Central

    Jiang, Manrong; Zhu, Kejin; Grenet, Jose; Lahti, Jill M.

    2008-01-01

    Caspase-8 is frequently deleted or silenced in neuroblastoma and other solid tumor such as medulloblastoma and small cell lung carcinoma. Caspase-8 expression can be re-established in neuroblastoma cell lines by treatment with demethylating agents or with IFN-γ Here we show that four different retinoic acid (RA) derivatives also increase caspase-8 protein expression in neuroblastoma, medulloblastoma and small cell lung carcinoma cell lines. This increase in protein expression is mirrored by an increase in RNA expression in NB cells. However, the promoter region of the caspase-8 gene was not responsible for the induction of caspase-8 expression. Rather, we identified another intronic region containing a CREB binding site that was required for maximal induction of caspase-8 via RA. DNA-protein interaction assays revealed increased phospho-CREB binding to this response element in RA-treated NB cells. Furthermore, both mutation of the CREB binding site completely blocked caspase-8 induction in the luciferase reporter system assay and transfection of dominant-negative form of CREB repressed the up-regulation of caspase-8 by RA. Importantly, RA-released cells maintained caspase-8 expression for at least 2–5 days and were more sensitive to doxorubicin and TNFα. Thus, RA treatment in conjunction with TNFα and/or subsets of cytotoxic agents may have therapeutic benefits. PMID:18342014

  1. Urea derivates of ursolic, oleanolic and maslinic acid induce apoptosis and are selective cytotoxic for several human tumor cell lines.

    PubMed

    Sommerwerk, Sven; Heller, Lucie; Kuhfs, Julia; Csuk, René

    2016-08-25

    2,3-Di-O-acetyl-maslinic acid benzylamide (5) has previously been shown to possess high cytotoxicity for a variety of human tumor cell lines while being of low cytotoxicity to non-malignant cells. Structural modifications performed on 5 revealed that the presence of these acetyl groups in 5 and the presence of (2β,3β)-configurated centers seems necessary for obtaining high cytotoxicity combined with best selectivity between malignant cells and non-malignant mouse fibroblasts. Compounds carrying an ursane skeleton showed weaker cytotoxicity than their oleanane derived analogs. In addition, the benzylamide function in compound 5 should be replaced by a phenylurea moiety to gain better cytotoxicity while retaining and improving the selectivity. Thus, maslinic acid derived N-[2β,3β-di-O-acetyl-17β-amino-28-norolean-12-en-17-yl]phenylurea (45) gave best results showing EC50 = 0.9 μM (for A2780 ovarian cancer cells) with EC50 > 120 μM for fibroblasts (NIH 3T3) and triggered apoptosis while caspase-3 was not activated by this compound. PMID:27149037

  2. Regulatory CD8{sup +} T cells induced by exposure to all-trans retinoic acid and TGF-{beta} suppress autoimmune diabetes

    SciTech Connect

    Kishi, Minoru; Yasuda, Hisafumi; Abe, Yasuhisa; Sasaki, Hirotomo; Shimizu, Mami; Arai, Takashi; Okumachi, Yasuyo; Moriyama, Hiroaki; Hara, Kenta; Yokono, Koichi; Nagata, Masao

    2010-03-26

    Antigen-specific regulatory CD4{sup +} T cells have been described but there are few reports on regulatory CD8{sup +} T cells. We generated islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)-specific regulatory CD8{sup +} T cells from 8.3-NOD transgenic mice. CD8{sup +} T cells from 8.3-NOD splenocytes were cultured with IGRP, splenic dendritic cells (SpDCs), TGF-{beta}, and all-trans retinoic acid (ATRA) for 5 days. CD8{sup +} T cells cultured with either IGRP alone or IGRP and SpDCs in the absence of TGF-{beta} and ATRA had low Foxp3{sup +} expression (1.7 {+-} 0.9% and 3.2 {+-} 4.5%, respectively). In contrast, CD8{sup +} T cells induced by exposure to IGRP, SpDCs, TGF-{beta}, and ATRA showed the highest expression of Foxp3{sup +} in IGRP-reactive CD8{sup +} T cells (36.1 {+-} 10.6%), which was approximately 40-fold increase compared with that before induction culture. CD25 expression on CD8{sup +} T cells cultured with IGRP, SpDCs, TGF-{beta}, and ATRA was only 7.42%, whereas CD103 expression was greater than 90%. These CD8{sup +} T cells suppressed the proliferation of diabetogenic CD8{sup +} T cells from 8.3-NOD splenocytes in vitro and completely prevented diabetes onset in NOD-scid mice in cotransfer experiments with diabetogenic splenocytes from NOD mice in vivo. Here we show that exposure to ATRA and TGF-{beta} induces CD8{sup +}Foxp3{sup +} T cells ex vivo, which suppress diabetogenic T cells in vitro and in vivo.

  3. Docosahexaenoic Acid Modulates a HER2-Associated Lipogenic Phenotype, Induces Apoptosis, and Increases Trastuzumab Action in HER2-Overexpressing Breast Carcinoma Cells

    PubMed Central

    Ravacci, Graziela Rosa; Brentani, Maria Mitzi; Tortelli, Tharcisio Citrângulo; Torrinhas, Raquel Suzana M. M.; Santos, Jéssica Reis; Logullo, Angela Flávia; Waitzberg, Dan Linetzky

    2015-01-01

    In breast cancer, lipid metabolic alterations have been recognized as potential oncogenic stimuli that may promote malignancy. To investigate whether the oncogenic nature of lipogenesis closely depends on the overexpression of HER2 protooncogene, the normal breast cell line, HB4a, was transfected with HER2 cDNA to obtain HER2-overexpressing HB4aC5.2 cells. Both cell lines were treated with trastuzumab and docosahexaenoic acid. HER2 overexpression was accompanied by an increase in the expression of lipogenic genes involved in uptake (CD36), transport (FABP4), and storage (DGAT) of exogenous fatty acids (FA), as well as increased activation of “de novo” FA synthesis (FASN). We further investigate whether this lipogenesis reprogramming might be regulated by mTOR/PPARγ pathway. Inhibition of the mTORC1 pathway markers, p70S6 K1, SREBP1, and LIPIN1, as well as an increase in DEPTOR expression (the main inhibitor of the mTOR) was detected in HB4aC5.2. Based on these results, a PPARγ selective antagonist, GW9662, was used to treat both cells lines, and the lipogenic genes remained overexpressed in the HB4aC5.2 but not HB4a cells. DHA treatment inhibited all lipogenic genes (except for FABP4) in both cell lines yet only induced death in the HB4aC5.2 cells, mainly when associated with trastuzumab. Neither trastuzumab nor GW9662 alone was able to induce cell death. In conclusion, oncogenic transformation of breast cells by HER2 overexpression may require a reprogramming of lipogenic genetic that is independent of mTORC1 pathway and PPARγ activity. This reprogramming was inhibited by DHA. PMID:26640797

  4. Alpha-lipoic acid attenuates endoplasmic reticulum stress-induced insulin resistance by improving mitochondrial function in HepG2 cells.

    PubMed

    Lei, Lin; Zhu, Yiwei; Gao, Wenwen; Du, Xiliang; Zhang, Min; Peng, Zhicheng; Fu, Shoupeng; Li, Xiaobing; Zhe, Wang; Li, Xinwei; Liu, Guowen

    2016-10-01

    Alpha-lipoic acid (ALA) has been reported to have beneficial effects for improving insulin sensitivity. However, the underlying molecular mechanism of the beneficial effects remains poorly understood. Endoplasmic reticulum (ER) stress and mitochondrial dysfunction are considered causal factors that induce insulin resistance. In this study, we investigated the effect of ALA on the modulation of insulin resistance in ER-stressed HepG2 cells, and we explored the potential mechanism of this effect. HepG2 cells were incubated with tunicamycin (Tun) for 6h to establish an ER stress cell model. Tun treatment induced ER stress, mitochondrial dysfunction and insulin resistance. Interestingly, ALA had no significant effect on ER stress signals. Pretreatment of the ER stress cell model with ALA for 24h improved insulin sensitivity, restored the expression levels of mitochondrial oxidative phosphorylation (OXPHOS) complexes and increased intracellular ATP production. Moreover, ALA augmented the β-oxidation capacity of the mitochondria. Importantly, ALA treatment could decrease oligomycin-induced mitochondrial dysfunction and then improved insulin resistance. Taken together, our data suggest that ALA prevents ER stress-induced insulin resistance by enhancing mitochondrial function. PMID:27377964

  5. Sargahydroquinoic acid inhibits TNFα-induced AP-1 and NF-κB signaling in HaCaT cells through PPARα activation.

    PubMed

    Jeon, Youngsic; Jung, Yujung; Kim, Min Cheol; Kwon, Hak Cheol; Kang, Ki Sung; Kim, Yong Kee; Kim, Su-Nam

    2014-08-01

    Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors and expressed in various cell types in the skin, including keratinocytes, fibroblasts and infiltrating immune cells. Thus, their ligands are targets for the treatment of various skin disorders, such as photo-aging and chronological aging of skin. Intensive studies have revealed that PPARα/γ functions in photo-aging and age-related inflammation by regulating matrix metalloproteinases (MMPs) via activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB). However, the detailed mechanism of PPARα/γ's role in skin aging has not yet been elucidated. In this study, we confirmed that sargahydroquinoic acid (SHQA) as a PPARα/γ ligand significantly decreased Tumor Necrosis Factor-alpha (TNFα)-induced MMP-2/-9 expression by downregulating TNFα-induced transcription factors, subsequently reducing IκBα degradation and blocking NF-κB p65 nuclear translocation in HaCaT human epidermal keratinocyte cells. Treatment of cells with SHQA and GW6471 (PPARα antagonist) not bisphenol A diglycidyl ether (PPARγ antagonists), reversed the effect on TNFα-induced inflammatory signaling pathway activation. Taken together, our data suggest that SHQA inhibit TNFα-induced MMP-2/-9 expression and age-related inflammation by suppressing AP-1 and NF-κB pathway via PPARα. PMID:25019995

  6. Gardenia jasminoides extracts and gallic acid inhibit lipopolysaccharide-induced inflammation by suppression of JNK2/1 signaling pathways in BV-2 cells

    PubMed Central

    Lin, Wen-Hung; Kuo, Heng-Hung; Ho, Li-Hsing; Tseng, Ming-Lang; Siao, An-Ci; Hung, Chang-Tsen; Jeng, Kee-Ching; Hou, Chien-Wei

    2015-01-01

    Objective(s): Gardenia jasminoides Ellis (GJ, Cape Jasmine Fruit, Zhi Zi) has been traditionally used for the treatment of infectious hepatitis, aphthous ulcer, and trauma; however, the direct evidence is lacking. Materials and Methods: We investigated the effect of the GJ extract (GJ) and gallic acid (GA) on lipopolysaccharide (LPS) induced inflammation of BV-2 microglial cells and acute liver injury in Sprague-Dawley (SD) rats. Results: Our results showed that the GJ extract and GA reduced LPS-induced nitric oxide (NO), interleukin (IL)-1, IL-6, reactive oxygen species (ROS), and prostaglandin (PGE2) production in BV-2 cells. The GJ extract and GA significantly decreased serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in LPS-treated rats. Furthermore, the water extract, but not the ethanol extract, of the GJ dose-dependently inhibited LPS-induced JNK2/1 and slightly p38 mitogen-activated protein kinases (MAPK), and cyclooxygenase-2 (COX-2) expression in BV-2 cells. Conclusion: Taken together, these results indicate that the protective mechanism of the GJ extract involves an antioxidant effect and inhibition of JNK2/1 MAP kinase and COX-2 expressions in LPS-induced inflammation of BV-2 cells. PMID:26221479

  7. Caffeic acid phenethyl ester enhances TRAIL-mediated apoptosis via CHOP-induced death receptor 5 upregulation in hepatocarcinoma Hep3B cells.

    PubMed

    Dilshara, Matharage Gayani; Jayasooriya, Rajapaksha Gedara Prasad Tharanga; Park, Sang Rul; Choi, Yung-Hyun; Choi, Il-Whan; Kim, Gi-Young

    2016-07-01

    Caffeic acid phenethyl ester (CAPE) exhibits various pharmaceutical properties, including anti-bacterial, anti-inflammatory, anti-viral, anti-cancer, and anti-oxidative activity. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been a promising anti-cancer agent that preferentially induces cancer cell apoptosis with negligible cytotoxicity toward normal cells. Therefore, the present study investigated whether CAPE promotes TRAIL-mediated cytotoxicity in hepatocarcinoma Hep3B cells. The present study demonstrated that CAPE sensitized TRAIL-mediated cell death in Hep3B carcinoma cells. The percentages of the apoptotic cells and annexin-V(+) cells significantly increased in combined treatment with CAPE and TRAIL (CAPE/TRAIL). Treatment with pancaspase inhibitor, z-VAD-fmk, attenuated CAPE/TRAIL-induced apoptosis, suggesting that the combined treatment triggers caspase-dependent apoptosis. Additionally, we found that CAPE stimulated the expression of death receptor 5 (DR5) and treatment with DR5/Fc chimera protein significantly blocked CAPE/TRAIL-induced apoptosis, which indicates that CAPE/TRAIL stimulated apoptosis through the binding of TRAIL to DR5. Moreover, expression of transcription factor C/EBP homologous protein (CHOP) markedly increased in response to CAPE and transient knockdown of CHOP abolished CAPE/TRAIL-mediated apoptosis. These results suggest that CHOP is a key regulator in CAPE/TRAIL-mediated apoptosis. Taken together, the present study found that CAPE significantly enhanced TRAIL-mediated apoptosis in Hep3B carcinoma cells and suggested that CAPE has promising potential in chemoprevention of hepatocellular carcinomas. PMID:27260301

  8. Stress-induced NF-κB activation differentiates promyelocytic leukemia cells to macrophages in response to all-trans-retinoic acid.

    PubMed

    Imran, Muhammad; Park, Joon Seong; Lim, In Kyoung

    2015-03-01

    All-trans-retinoic acid (ATRA) has been known as a choice of treatment for inducing differentiation of promyelocytic leukemia cells to granulocytes. NF-κB plays a crucial role in inflammation and immunity and its activation is an important event for macrophage differentiation both in vivo and in vitro. We report here that NF-κB activation is critical for determining ATRA-induced lineage specific differentiation of myeloid leukemia cells. Our data revealed that ATRA treatment to HL-60 cells enhanced IκBα degradation and NF-κB nuclear translocation and the activated NF-κB potentiated the ability of ATRA for differentiation and switched differentiation to macrophages instead of granulocytes. Serum withdrawal and LPS treatment dampened IκBα expression via MAPK activation and reactive oxygen species generation leading to NF-κB nuclear translocation and ATRA treatment further corroborated these effects in myeloid leukemia cells. Activated NF-κB enhanced the degree of ATRA-induced differentiation of HL-60 cells to macrophages, rather than granulocytes, as assessed by morphologic examination and expressions of differentiation markers such as CD11b, CD38, CD68, MMP9 and Btg2. Employing LLnL or dominant negative IκBα attenuated NF-κB associated enhanced cell maturation and differentiation switch thus suggesting NF-κB as one of the factors that determines ATRA induced lineage specificity of myeloid leukemia cells. Furthermore, MAPK activation was observed to be central both for the differentiation of promyelocytic cells to macrophages or granulocytes regulating NF-κB or C/EBPα expressions, respectively; however, MAPK-mediated signals are modulated under various conditions affecting lineage specificity. In summary, our present data demonstrate that activation of NF-κB directly affects differentiation program of promyelocytes to macrophages, rather than granulocyte, in response to ATRA treatment. PMID:25435432

  9. Omega-3 Polyunsaturated Fatty Acids May Attenuate Streptozotocin-Induced Pancreatic β-Cell Death via Autophagy Activation in Fat1 Transgenic Mice

    PubMed Central

    Hwang, Won-Min; Bak, Dong-Ho; Kim, Dong Ho; Hong, Ju Young; Han, Seung-Yun; Park, Keun-Young; Lim, Kyu; Kang, Jae Gu

    2015-01-01

    Background Inflammatory factors and β-cell dysfunction due to high-fat diets aggravate chronic diseases and their complications. However, omega-3 dietary fats have anti-inflammatory effects, and the involvement of autophagy in the etiology of diabetes has been reported. Therefore, we examined the protective effects of autophagy on diabetes using fat-1 transgenic mice with omega-3 self-synthesis capability. Methods Streptozotocin (STZ) administration induced β-cell dysfunction in mice; blood glucose levels and water consumption were subsequently measured. Using hematoxylin and eosin (H&E) and Masson's trichrome staining, we quantitatively assessed STZ-induced changes in the number, mass, and fibrosis of pancreatic islets in fat-1 and control mice. We identified the microtubule-associated protein 1A/1B light chain 3-immunoreactive puncta in β-cells and quantified p62 levels in the pancreas of fat-1 and control mice. Results STZ-induced diabetic phenotypes, including hyperglycemia and polydipsia, were attenuated in fat-1 mice. Histological determination using H&E and Masson's trichrome staining revealed the protective effects of the fat-1 expression on cell death and the scarring of pancreatic islets after STZ injection. In the β-cells of control mice, autophagy was abruptly activated after STZ treatment. Basal autophagy levels were elevated in fat-1 mice β-cells, and this persisted after STZ treatment. Together with autophagosome detection, these results revealed that n-3 polyunsaturated fatty acid (PUFA) enrichment might partly prevent the STZ-related pancreatic islet damage by upregulating the basal activity of autophagy and improving autophagic flux disturbance. Conclusion Fat-1 transgenic mice with a n-3 PUFA self-synthesis capability exert protective effects against STZ-induced β-cell death by activating autophagy in β-cells. PMID:26790385

  10. Rosmarinic Acid suppressed high glucose-induced apoptosis in H9c2 cells by ameliorating the mitochondrial function and activating STAT3.

    PubMed

    Diao, Jiayu; Wei, Jin; Yan, Rui; Liu, Xin; Li, Qing; Lin, Lin; Zhu, Yanhe; Li, Hong

    2016-09-01

    Mitochondrial injury characterized by intracellular reactive oxygen species (ROS) accumulation plays a critical role in hyperglycemia-induced myocardium dysfunction. Previous studies have demonstrated that Rosmarinic Acid (RA) treatment and activating Signal transducer and activator of transcription 3 (STAT3) signaling pathway have protective effects on mitochondrial dysfunction in cardiomyocyte, but there is little data regarding cardiomyocyte under condition of high-glucose. The present study was undertaken to determine the relationship between RA and STAT3 activation, as well as their effects on high glucose-induced mitochondrial injury and apoptosis in H9c2 cardiomyocyte. Our results revealed that RA pretreatment suppressed high glucose-induced apoptosis in H9c2 cells. Moreover, the effect of RA on apoptosis was related with improved mitochondrial function, which was demonstrated by that RA attenuated high glucose-induced ROS generation, inhibited mitochondrial permeability transition pore (MPTP) activation, suppressed cytochrome c release and caspase-3 activation. In addition, the phosphorylation of STAT3 in H9c2 cells was inhibited under condition of high-glucose, but RA improved STAT3 phosphorylation. Importantly, inhibition of STAT3 expression by using STAT3-siRNA partly suppressed the effect of RA on high glucose-induced apoptosis. Taken together, pretreatment with RA suppressed high glucose-induced apoptosis in cardiomyocyte by ameliorating mitochondrial function and activating STAT3. PMID:27402269

  11. Disruption of BSEP Function in HepaRG Cells Alters Bile Acid Disposition and Is a Susceptive Factor to Drug-Induced Cholestatic Injury.

    PubMed

    Qiu, Xi; Zhang, Yueping; Liu, Tongtong; Shen, Hong; Xiao, Yongling; Bourner, Maureen J; Pratt, Jennifer R; Thompson, David C; Marathe, Punit; Humphreys, W Griffith; Lai, Yurong

    2016-04-01

    In the present study, we characterized in vitro biosynthesis and disposition of bile acids (BAs) as well as hepatic transporter expression followed by ABCB11 (BSEP) gene knockout in HepaRG cells (HepaRG-KO cells). BSEP KO in HepaRG cells led to time-dependent BA accumulation, resulting in reduced biosynthesis of BAs and altered BA disposition. In HepaRG-KO cells, the expression of NTCP, OATP1B1, OATP2B1, BCRP, P-gp, and MRP2 were reduced, whereas MRP3 and OCT1 were up-regulated. As a result, BSEP KO altered the disposition of BAs and subsequently underwent adaptive regulations of BA synthesis and homeostasis to enable healthy growth of the cells. Although BSEP inhibitors caused no or slight increase of BAs in HepaRG wild type cells (HepaRG-WT cells), excessive intracellular accumulation of BAs was observed in HepaRG-KO cells exposed to bosentan and troglitazone, but not dipyridamole. LDH release in the medium was remarkably increased in HepaRG-KO cultures exposed to troglitazone (50 μM), suggesting drug-induced cellular injury. The results revealed that functional impairment of BSEP predisposes the cells to altered BA disposition and is a susceptive factor to drug-induced cholestatic injury. In total, BSEP inhibition might trigger the processes but is not a sole determinant of cholestatic cellular injury. As intracellular BA accumulation is determined by BSEP function and the subsequent adaptive gene regulation, assessment of intracellular BA accumulation in HepaRG-KO cells could be a useful approach to evaluate drug-induced liver injury (DILI) potentials of drugs that could disrupt other BA homeostasis pathways beyond BSEP inhibition. PMID:26910619

  12. Mitochondrial genome depletion dysregulates bile acid- and paracetamol-induced expression of the transporters Mdr1, Mrp1 and Mrp4 in liver cells

    PubMed Central

    Perez, MJ; Gonzalez-Sanchez, E; Gonzalez-Loyola, A; Gonzalez-Buitrago, JM; Marin, JJG

    2011-01-01

    BACKGROUND AND PURPOSE Mitochondria are involved in the toxicity of several compounds, retro-control of gene expression and apoptosis activation. The effect of mitochondrial genome (mtDNA) depletion on changes in ABC transporter protein expression in response to bile acids and paracetamol was investigated. EXPERIMENTAL APPROACH Hepa 1-6 mouse hepatoma cells with 70% decrease in 16S/18S rRNA ratio (Rho cells) were obtained by long-term treatment with ethidium bromide. KEY RESULTS Spontaneous apoptosis and reactive oxygen species (ROS) generation were decreased in Rho cells. Following glycochenodeoxycholic acid (GCDCA) or paracetamol, Rho cells generated less ROS and were more resistant to cell death. Apoptosis induced by GCDCA and Fas was also reduced. The basal expression of Mdr1 was significantly enhanced, but this was not further stimulated by GCDCA or paracetamol, as observed in wild-type (WT) cells. Basal expression of Mrp1 and Mrp4 was similar in WT and Rho cells, whereas they were up-regulated only in WT cells after GCDCA or paracetamol, along with the transcription factors Shp and Nrf2, but not Fxr or Pxr. Increased expression of Nrf2 was accompanied by its enhanced nuclear translocation. Glycoursodeoxycholic acid failed to cause any of the effects observed for GCDCA or paracetamol. CONCLUSIONS AND IMPLICATIONS The Nrf2-mediated pathway is partly independent of ROS production. Nuclear translocation of Nrf2 is insufficient to up-regulate Mdr1, Mrp1 and Mrp4, which requires the participation of other regulatory element(s) whose activation in response to GCDCA and paracetamol is impaired in Rho cells and hence probably sensitive to ROS. PMID:21175587

  13. Sargahydroquinoic acid inhibits TNFα-induced AP-1 and NF-κB signaling in HaCaT cells through PPARα activation

    SciTech Connect

    Jeon, Youngsic; Jung, Yujung; Kim, Min Cheol; Kwon, Hak Cheol; Kang, Ki Sung; Kim, Yong Kee; Kim, Su-Nam

    2014-08-08

    Highlights: • SHQA increases PPARα/γ transactivation and inhibits MMP-2/-9 expression. • SHQA inhibits TNFα-induced AP-1 and MAPK signaling. • SHQA inhibits TNFα-induced p65 translocation and IκBα phosphorylation. • SHQA inhibits TNFα-induced AP-1 and NF-κB signaling via PPARα. - Abstract: Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors and expressed in various cell types in the skin, including keratinocytes, fibroblasts and infiltrating immune cells. Thus, their ligands are targets for the treatment of various skin disorders, such as photo-aging and chronological aging of skin. Intensive studies have revealed that PPARα/γ functions in photo-aging and age-related inflammation by regulating matrix metalloproteinases (MMPs) via activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB). However, the detailed mechanism of PPARα/γ’s role in skin aging has not yet been elucidated. In this study, we confirmed that sargahydroquinoic acid (SHQA) as a PPARα/γ ligand significantly decreased Tumor Necrosis Factor-alpha (TNFα)-induced MMP-2/-9 expression by downregulating TNFα-induced transcription factors, subsequently reducing IκBα degradation and blocking NF-κB p65 nuclear translocation in HaCaT human epidermal keratinocyte cells. Treatment of cells with SHQA and GW6471 (PPARα antagonist) not bisphenol A diglycidyl ether (PPARγ antagonists), reversed the effect on TNFα-induced inflammatory signaling pathway activation. Taken together, our data suggest that SHQA inhibit TNFα-induced MMP-2/-9 expression and age-related inflammation by suppressing AP-1 and NF-κB pathway via PPARα.

  14. Oleanolic acid induces mitochondrial-dependent apoptosis and G0/G1 phase arrest in gallbladder cancer cells

    PubMed Central

    Li, Huai-Feng; Wang, Xu-An; Xiang, Shan-Shan; Hu, Yun-Ping; Jiang, Lin; Shu, Yi-Jun; Li, Mao-Lan; Wu, Xiang-Song; Zhang, Fei; Ye, Yuan-Yuan; Weng, Hao; Bao, Run-Fa; Cao, Yang; Lu, Wei; Dong, Qian; Liu, Ying-Bin

    2015-01-01

    Oleanolic acid (OA), a naturally occurring triterpenoid, exhibits potential antitumor activity in many tumor cell lines. Gallbladder carcinoma is the most common malignancy of the biliary tract, and is a highly aggressive tumor with an extremely poor prognosis. Unfortunately, the effects of OA on gallbladder carcinoma are unknown. In this study, we investigated the effects of OA on gallbladder cancer cells and the underlying mechanism. The results showed that OA inhibits proliferation of gallbladder cancer cells in a dose-dependent and time-dependent manner on MTT and colony formation assay. A flow cytometry assay revealed apoptosis and G0/G1 phase arrest in GBC-SD and NOZ cells. Western blot analysis and a mitochondrial membrane potential assay demonstrated that OA functions through the mitochondrial apoptosis pathway. Moreover, this drug inhibited tumor growth in nude mice carrying subcutaneous NOZ tumor xenografts. These data suggest that OA inhibits proliferation of gallbladder cancer cells by regulating apoptosis and the cell cycle process. Thus, OA may be a promising drug for adjuvant chemotherapy in gallbladder carcinoma. PMID:26109845

  15. MicroRNA-31 negatively regulates peripherally derived regulatory T-cell generation by repressing retinoic acid-inducible protein 3.

    PubMed

    Zhang, Lingyun; Ke, Fang; Liu, Zhaoyuan; Bai, Jing; Liu, Jinlin; Yan, Sha; Xu, Zhenyao; Lou, Fangzhou; Wang, Hong; Zhu, Huiyuan; Sun, Yang; Cai, Wei; Gao, Yuanyuan; Li, Qun; Yu, Xue-Zhong; Qian, Youcun; Hua, Zichun; Deng, Jiong; Li, Qi-Jing; Wang, Honglin

    2015-01-01

    Peripherally derived regulatory T (pT(reg)) cell generation requires T-cell receptor (TCR) signalling and the cytokines TGF-β1 and IL-2. Here we show that TCR signalling induces the microRNA miR-31, which negatively regulates pT(reg)-cell generation. miR-31 conditional deletion results in enhanced induction of pT(reg) cells, and decreased severity of experimental autoimmune encephalomyelitis (EAE). Unexpectedly, we identify Gprc5a as a direct target of miR-31. Gprc5a is known as retinoic acid-inducible protein 3, and its deficiency leads to impaired pT(reg-)cell induction and increased EAE severity. By generating miR-31 and Gprc5a double knockout mice, we show that miR-31 promotes the development of EAE through inhibiting Gprc5a. Thus, our data identify miR-31 and its target Gprc5a as critical regulators for pT(reg)-cell generation, suggesting a previously unrecognized epigenetic mechanism for dysfunctional T(reg) cells in autoimmune diseases. PMID:26165721

  16. Acid shock of Listeria monocytogenes at low environmental temperatures induces prfA, epithelial cell invasion, and lethality towards Caenorhabditis elegans

    PubMed Central

    2013-01-01

    Background The saprophytic pathogen Listeria monocytogenes has to cope with a variety of acidic habitats during its life cycle. The impact of low-temperature coupled with pH decrease for global gene expression and subsequent virulence properties, however, has not been elucidated. Results qRT-PCR revealed for the first time a transient, acid triggered prfA induction of approximately 4-fold, 5.7-fold, 7-fold and 9.3-fold 60 to 90 min after acid shock of L. monocytogenes at 37°C, 25°C, 18°C, and 10°C, respectively. Comparable data were obtained for seven different L. monocytogenes strains, demonstrating that prfA induction under these conditions is a general response of L. monocytogenes. Transcriptome analysis revealed that the in vivo-relevant genes bsh, clpP, glpD, hfq, inlA, inlB, inlE, lisR, and lplA1 as well as many other genes with a putative role during infection are transiently induced upon acid shock conducted at 25°C and 37°C. Twenty-five genes repressed upon acid shock are known to be down regulated during intracellular growth or by virulence regulators. These data were confirmed by qRT-PCR of twelve differentially regulated genes and by the identification of acid shock-induced genes influenced by σB. To test if up regulation of virulence genes at temperatures below 37°C correlates with pathogenicity, the capacity of L. monocytogenes to invade epithelial cells after acid shock at 25°C was measured. A 12-fold increased number of intracellular bacteria was observed (acid shock, t = 60 min) that was reduced after adaptation to the level of the unshocked control. This increased invasiveness was shown to be in line with the induction of inlAB. Using a nematode infection assay, we demonstrated that Caenorhabditis elegans fed with acid-shocked L. monocytogenes exhibits a shorter time to death of 50% (TD50) of the worms (6.4 days) compared to infection with unshocked bacteria (TD50 = 10.2 days). Conclusions PrfA and other listerial virulence genes are

  17. Arsenic trioxide and all-trans retinoic acid target NPM1 mutant oncoprotein levels and induce apoptosis in NPM1-mutated AML cells.

    PubMed

    Martelli, Maria Paola; Gionfriddo, Ilaria; Mezzasoma, Federica; Milano, Francesca; Pierangeli, Sara; Mulas, Floriana; Pacini, Roberta; Tabarrini, Alessia; Pettirossi, Valentina; Rossi, Roberta; Vetro, Calogero; Brunetti, Lorenzo; Sportoletti, Paolo; Tiacci, Enrico; Di Raimondo, Francesco; Falini, Brunangelo

    2015-05-28

    Nucleophosmin (NPM1) mutations represent an attractive therapeutic target in acute myeloid leukemia (AML) because they are common (∼30% AML), stable, and behave as a founder genetic lesion. Oncoprotein targeting can be a successful strategy to treat AML, as proved in acute promyelocytic leukemia by treatment with all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO), which degrade the promyelocytic leukemia (PML)-retinoic acid receptor fusion protein. Adjunct of ATRA to chemotherapy was reported to be beneficial for NPM1-mutated AML patients. Leukemic cells with NPM1 mutation also showed sensibility to ATO in vitro. Here, we explore the mechanisms underlying these observations and show that ATO/ATRA induce proteasome-dependent degradation of NPM1 leukemic protein and apoptosis in NPM1-mutated AML cell lines and primary patients' cells. We also show that PML intracellular distribution is altered in NPM1-mutated AML cells and reverted by arsenic through oxidative stress induction. Interestingly, similarly to what was described for PML, oxidative stress also mediates ATO-induced degradation of the NPM1 mutant oncoprotein. Strikingly, NPM1 mutant downregulation by ATO/ATRA was shown to potentiate response to the anthracyclin daunorubicin. These findings provide experimental evidence for further exploring ATO/ATRA in preclinical NPM1-mutated AML in vivo models and a rationale for exploiting these compounds in chemotherapeutic regimens in clinics. PMID:25795919

  18. Aluminium-induced phospholipid signal transduction pathway in Coffea arabica suspension cells and its amelioration by silicic acid.

    PubMed

    Quintal-Tun, Fausto; Muñoz-Sánchez, J Armando; Ramos-Díaz, Ana; Escamilla-Bencomo, Armando; Martínez-Estévez, Manuel; Exley, Christopher; Hernández-Sotomayor, S M Teresa

    2007-02-01

    Coffee (Coffea arabica L.) is of economic importance worldwide. Its growth in organic-rich acidic soils is influenced by aluminium such that coffee yield may be impaired. Herein we have used the Al-sensitive C. arabica suspension cell line L2 to analyse the effect of two different Al species on the phosphoinositide signal transduction pathway. Our results have shown that the association of Al with coffee cells was affected by the pH and the form of Al in media. More Al was associated with cells at pH 4.3 than 5.8, whereas when Al was present as hydroxyaluminosilicates (HAS) the association was halved at pH 4.3 and unchanged at pH 5.8. Two signal transduction elements were also evaluated; phospholipase C (PLC) activity and phosphatidic acid (PA) formation. PLC was inhibited ( approximately 50%) when cells were incubated for 2 h in the presence of either AlCl(3) or Al in the form of HAS. PA formation was tested as a short-term response to Al. By way of contrast to what was found for PLC, incubation of cells for 15 min in the presence of AlCl(3) decreased the formation of PA whereas the same concentration of Al as HAS produced no effect upon its formation. These results suggest that Al is capable to exert its effects upon signal transduction as Al((aq))(3+) acting upon a mechanism linked to the phosphoinositide signal transduction pathway. PMID:17161461

  19. gamma-Aminobutyric acid (GABA)-induced currents of skate Muller (glial) cells are mediated by neuronal-like GABAA receptors.

    PubMed Central

    Malchow, R P; Qian, H H; Ripps, H

    1989-01-01

    Radial glia (Muller cells) of the vertebrate retina appear to be intimately involved in regulating the actions of amino acid neurotransmitters. One of the amino acids thought to be important in mediating retinal information flow is gamma-aminobutyric acid (GABA). The findings of this study indicate that enzymatically isolated skate Muller cells are depolarized by GABA and the GABAA agonist muscimol and that the actions of these agents are reduced by bicuculline and picrotoxin. Membrane currents induced by GABA under voltage clamp were dose dependent, were associated with an increase in membrane conductance, and showed marked desensitization when the concentration of GABA exceeded 2.5 microM. The responses had a reversal potential close to that calculated for chloride, indicating that the currents were generated by ions passing through channels. These data support the view that skate Muller cells possess functional GABAA receptors. The presence of such receptors on retinal glia may have important implications for the role of Muller cells in maintaining the constancy of the extracellular milieu, for neuron-glia interactions within the retina, and for theories concerning the generation of the electroretinogram. Images PMID:2567001

  20. Effect of Vitamin E and Omega-3 Fatty Acids on Protecting Ambient PM2.5-Induced Inflammatory Response and Oxidative Stress in Vascular Endothelial Cells

    PubMed Central

    Bo, Liang; Jiang, Shuo; Xie, Yuquan; Kan, Haidong; Song, Weimin; Zhao, Jinzhuo

    2016-01-01

    Although the mechanisms linking cardiopulmonary diseases to ambient fine particles (PM2.5) are still unclear, inflammation and oxidative stress play important roles in PM2.5-induced injury. It is well known that inflammation and oxidative stress could be restricted by vitamin E (Ve) or omega-3 fatty acids (Ω-3 FA) consumption. This study investigated the effects of Ve and Ω-3 FA on PM2.5-induced inflammation and oxidative stress in vascular endothelial cells. The underlying mechanisms linking PM2.5 to vascular endothelial injury were also explored. Human umbilical vein endothelial cells (HUVECs) were treated with 50 μg/mL PM2.5 in the presence or absence of different concentrations of Ve and Ω-3 FA. The inflammatory cytokines and oxidative stress markers were determined. The results showed that Ve induced a significant decrease in PM2.5-induced inflammation and oxidative stress. Malondialdehyde (MDA) in supernatant and reactive oxygen species (ROS) in cytoplasm decreased by Ve, while the superoxide dismutase (SOD) activity elevated. The inflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) also reduced by Ve. Moreover, Ω-3 FA played the same role on decreasing the inflammation and oxidative stress. IL-6 and TNF-α expressions were significantly lower in combined Ve with Ω-3 FA than treatment with Ve or Ω-3 FA alone. The Ve and Ω-3 FA intervention might abolish the PM2.5-induced oxidative stress and inflammation in vascular endothelial cells. There might be an additive effect of these two nutrients in mediating the PM2.5-induced injury in vascular endothelial cells. The results suggested that inflammation and oxidative stress might be parts of the mechanisms linking PM2.5 to vascular endothelial injury. PMID:27007186

  1. Effect of tolbutamide, glyburide and glipizide administered supraspinally on CA3 hippocampal neuronal cell death and hyperglycemia induced by kainic acid in mice.

    PubMed

    Kim, Chea-Ha; Park, Soo-Hyun; Sim, Yun-Beom; Kim, Sung-Su; Kim, Su-Jin; Lim, Su-Min; Jung, Jun-Sub; Suh, Hong-Won

    2014-05-20

    Sulfonylureas are widely used oral drugs for the treatment of type II diabetes mellitus. In the present study, the effects of sulfonylureas administered supraspinally on kainic acid (KA)-induced hippocampal neuronal cell death and hyperglycemia were studied in ICR mice. Mice were pretreated intracerebroventricularly (i.c.v.) with 30μg of tolbutamide, glyburide or glipizide for 10min and then, mice were administered i.c.v. with KA (0.1μg). The neuronal cell death in the CA3 region in the hippocampus was assessed 24h after KA administration and the blood glucose level was measured 30, 60, and 120min after KA administration. We found that i.c.v. pretreatment with tolbutamide, glyburide or glipizide attenuated the KA-induced neuronal cell death in CA3 region of the hippocampus and hyperglycemia. In addition, KA administered i.c.v. caused an elevation of plasma corticosterone level and a reduction of the plasma insulin level. The i.c.v. pretreatment with tolbutamide, glyburide or glipizide attenuated KA-induced increase of plasma corticosterone level. Furthermore, i.c.v. pretreatment with tolbutamide, glyburide or glipizide causes an elevation of plasma insulin level. Glipizide, but not tolbutamide or glyburide, pretreated i.c.v. caused a reversal of KA-induced hypoinsulinemic effect. Our results suggest that supraspinally administered tolbutamide, glyburide and glipizide exert a protective effect against KA-induced neuronal cells death in CA3 region of the hippocampus. The neuroprotective effect of tolbutamide, glyburide and glipizide appears to be mediated by lowering the blood glucose level induced by KA. PMID:24713348

  2. Humic Acid Increases Amyloid β-Induced Cytotoxicity by Induction of ER Stress in Human SK-N-MC Neuronal Cells

    PubMed Central

    Li, Hsin-Hua; Lu, Fung-Jou; Hung, Hui-Chih; Liu, Guang-Yaw; Lai, Te-Jen; Lin, Chih-Li

    2015-01-01

    Humic acid (HA) is a possible etiological factor associated with for several vascular diseases. It is known that vascular risk factors can directly increase the susceptibility to Alzheimer’s disease (AD), which is a neurodegenerative disorder due to accumulation of amyloid β (Aβ) peptide in the brain. However, the role that HA contributes to Aβ-induced cytotoxicity has not been demonstrated. In the present study, we demonstrate that HA exhibits a synergistic effect enhancing Aβ-induced cytotoxicity in cultured human SK-N-MC neuronal cells. Furthermore, this deterioration was mediated through the activation of endoplasmic reticulum (ER) stress by stimulating PERK and eIF2α phosphorylation. We also observed HA and Aβ-induced cytotoxicity is associated with mitochondrial dysfunction caused by down-regulation of the Sirt1/PGC1α pathway, while in contrast, treating the cells with the ER stress inhibitor Salubrinal, or over-expression of Sirt1 significantly reduced loss of cell viability by HA and Aβ. Our findings suggest a new mechanism by which HA can deteriorate Aβ-induced cytotoxicity through modulation of ER stress, which may provide significant insights into the pathogenesis of AD co-occurring with vascular injury. PMID:25961951

  3. Sargaquinoic Acid Inhibits TNF-α-Induced NF-κB Signaling, Thereby Contributing to Decreased Monocyte Adhesion to Human Umbilical Vein Endothelial Cells (HUVECs).

    PubMed

    Gwon, Wi-Gyeong; Lee, Bonggi; Joung, Eun-Ji; Choi, Min-Woo; Yoon, Nayoung; Shin, Taisun; Oh, Chul-Woong; Kim, Hyeung-Rak

    2015-10-21

    Sargaquinoic acid (SQA) has been known for its antioxidant and anti-inflammatory properties. This study investigated the effects of SQA isolated from Sargassum serratifolium on the inhibition of tumor necrosis factor (TNF)-α-induced monocyte adhesion to human umbilical vein endothelial cells (HUVECs). SQA decreased the expression of cell adhesion molecules such as intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 as well as chemotactic cytokines such as interleukin-8 and monocyte chemoattractant protein-1 in TNF-α-treated HUVECs. As a result, SQA prevented monocyte adhesion to TNF-α-induced adhesion. SQA also inhibited TNF-α-induced nuclear factor kappa B (NF-κB) translocation into the nucleus by preventing proteolytic degradation of inhibitor κB-α. Overall, SQA protects against TNF-α-induced vascular inflammation through inhibition of the NF-κB pathway in HUVECs. These data suggest that SQA may be used as a therapeutic agent for vascular inflammatory diseases such as atherosclerosis. PMID:26437568

  4. Pulmonary Fibrosis Inducer, Bleomycin, Causes Redox-Sensitive Activation of Phospholipase D and Cytotoxicity Through Formation of Bioactive Lipid Signal Mediator, Phosphatidic Acid, in Lung Microvascular Endothelial Cells

    PubMed Central

    Patel, Rishi B.; Kotha, Sainath R.; Sherwani, Shariq I.; Sliman, Sean M.; Gurney, Travis O.; Loar, Brooke; Butler, Susan O’Connor; Morris, Andrew J.; Marsh, Clay B.; Parinandi, Narasimham L.

    2012-01-01

    The mechanisms of lung microvascular complications and pulmonary hypertension known to be associated with idiopathic pulmonary fibrosis (IPF), a debilitating lung disease, are not known. Therefore, we investigated whether bleomycin, the widely used experimental IPF inducer, would be capable of activating phospholipase D (PLD) and generating the bioactive lipid signal-mediator phosphatidic acid (PA) in our established bovine lung microvascular endothelial cell (BLMVEC) model. Our results revealed that bleomycin induced the activation of PLD and generation of PA in a dose-dependent (5, 10, and 100 μg) and time-dependent (2-12 hours) fashion that were significantly attenuated by the PLD-specific inhibitor, 5-fluoro-2-indolyl des-chlorohalopemide (FIPI). PLD activation and PA generation induced by bleomycin (5 μg) were significantly attenuated by the thiol protectant (N-acetyl-L-cysteine), antioxidants, and iron chelators suggesting the role of reactive oxygen species (ROS), lipid peroxidation, and iron therein. Furthermore, our study demonstrated the formation of ROS and loss of glutathione (GSH) in cells following bleomycin treatment, confirming oxidative stress as a key player in the bleomycin-induced PLD activation and PA generation in ECs. More noticeably, PLD activation and PA generation were observed to happen upstream of bleomycin-induced cytotoxicity in BLMVECs, which was protected by FIPI. This was also supported by our current findings that exposure of cells to exogenous PA led to internalization of PA and cytotoxicity in BLMVECs. For the first time, this study revealed novel mechanism of the bleomycin-induced redox-sensitive activation of PLD that led to the generation of PA, which was capable of inducing lung EC cytotoxicity, thus suggesting possible bioactive lipid-signaling mechanism/mechanisms of microvascular disorders encountered in IPF. PMID:21131602

  5. Structurally related ganoderic acids induce apoptosis in human cervical cancer HeLa cells: Involvement of oxidative stress and antioxidant protective system.

    PubMed

    Liu, Ru-Ming; Li, Ying-Bo; Liang, Xiang-Feng; Liu, Hui-Zhou; Xiao, Jian-Hui; Zhong, Jian-Jiang

    2015-10-01

    Ganoderic acids (GAs) produced by Ganoderma lucidum possess anticancer activities with the generation of reactive oxygen species (ROS). However, the role of oxidative stress in apoptotic process induced by GAs is still undefined. In this study, the effects of four structurally related GAs, i.e. GA-T, GA-Mk, and two deacetylated derivatives of GA-T (GA-T1 and GA-T2) on the antioxidant defense system and induced apoptosis in cervical cancer cells HeLa were investigated in vitro. Our results indicated that the tested GAs (5-40 μM) induced apoptotic cell death through mitochondrial membrane potential decrease and activation of caspase-9 and caspase-3. Furthermore, GAs increased the generation of intracellular ROS and attenuated antioxidant defense system by decreasing glutathione (GSH) level, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities. The above effects were remarkably blocked by the exogenous antioxidants, i.e. N-acetylcysteine, catalase and diphenyleneiodonium chloride. The potency of the four GAs toward induced apoptosis, generation of ROS and suppression of antioxidant defense system was in the order of: GA-T > GA-Mk ≈ GA-T1 > GA-T2 in HeLa cells. These findings suggest that GAs induced mitochondria-dependent cell apoptosis in HeLa cells are mediated via enhancing oxidative stress and depressing antioxidant defense. Additionally, the acetylation of hydroxyl groups in GAs may contribute to their pro-oxidant activities and cytotoxicity, which is helpful to the development of novel chemotherapy agents. PMID:26282491

  6. Low simvastatin concentrations reduce oleic acid-induced steatosis in HepG2 cells: An in vitro model of non-alcoholic fatty liver disease

    PubMed Central

    ALKHATATBEH, MOHAMMAD J.; LINCZ, LISA F.; THORNE, RICK F.

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is an inflammatory condition caused by hepatic lipid accumulation that is associated with insulin resistance, diabetes and metabolic syndrome. Although statins should be used with caution in liver diseases, they are increasingly investigated as a possible treatment for NAFLD. The present study recreated an in vitro model of NAFLD using HepG2 cells exposed to oleic acid (OA), which was used to quantify OA-induced lipid accumulation in HepG2 cells treated with various concentrations of simvastatin. In addition, the effect of simvastatin on HepG2 cell morphology and microparticle generation as a marker of cell apoptosis was assessed. OA-induced lipid accumulation was quantified by Oil Red O staining and extraction for optical density determination. Stained lipid droplets were visualized using phase contrast microscopy. Furthermore, HepG2 cell-derived microparticles were counted by flow cytometry subsequent to staining for Annexin V. HepG2 cells treated with 0–1 mM OA showed dose-dependent lipid accumulation. Treatment of HepG2 cells with increasing concentrations of simvastatin followed by treatment with 1 mM OA showed that low simvastatin concentrations (4–10 µM) were able to reduce lipid accumulation by ~40%, whereas high simvastatin concentrations (20 and 30 µM) induced apoptotic changes in cell morphology and increased the production of Annexin V+ microparticles. This suggests that low simvastatin doses may have a role in preventing NAFLD. However, further investigations are required to confirm this action in vivo and to determine the underlying mechanism by which simvastatin reduces hepatic steatosis. PMID:27073470

  7. A phenolic extract from grape by-products and its main hydroxybenzoic acids protect Caco-2 cells against pro-oxidant induced toxicity.

    PubMed

    Wang, S; Mateos, R; Goya, L; Amigo-Benavent, M; Sarriá, B; Bravo, L

    2016-02-01

    Grape/wine industry produces large amounts of by-products, however knowledge on their health-promoting qualities is limited. This study investigated the effects of a grape phenolic extract (GPE) and its phenolic compounds, gallic acid (GA) and syringic acid (SA) on human intestinal Caco-2 cells, directly or after cytotoxicity induced by tert-butylhydroperoxide (t-BOOH). Direct treatment with 0.1-10 μg/mL GPE, or 0.1-10 μM GA and SA produced no major cytotoxic effect, either changes in antioxidant defences (glutathione content, glutathione peroxidase and reductase activities) or protein damage (carbonyl groups). However, 10 μg/mL GPE, 1 and 10 μM GA and 10 μM SA decreased reactive oxygen species (ROS) production. Pre-treatment with GPE, SA and GA at the same concentrations for 20 h showed that 10 μg/mL GPE and 10 μM GA or SA significantly counteracted ROS increase induced by t-BOOH. 10 μg/mL GPE and 1-10 μM GA or 10 μM of SA significantly reduced pro-oxidant-induced cytotoxicity. 1-10 μg/mL GPE, 1-10 μM GA and 10 μM SA significantly recovered both depleted glutathione and enhanced glutathione reductase and peroxidase activities, and reduced protein oxidative damage. Therefore, treatment with realistic concentrations of GPE and its main hydroxybenzoic acids protected Caco-2 cells against induced oxidative stress. PMID:26708231

  8. AP-1 Inhibition by SR 11302 Protects Human Hepatoma HepG2 Cells from Bile Acid-Induced Cytotoxicity by Restoring the NOS-3 Expression

    PubMed Central

    González-Rubio, Sandra; Linares, Clara I.; Aguilar-Melero, Patricia; Rodríguez-Perálvarez, Manuel; Montero-Álvarez, José L.

    2016-01-01

    The harmful effects of bile acid accumulation occurring during cholestatic liver diseases have been associated with oxidative stress increase and endothelial nitric oxide synthase (NOS-3) expression decrease in liver cells. We have previously reported that glycochenodeoxycholic acid (GCDCA) down-regulates gene expression by increasing SP1 binding to the NOS-3 promoter in an oxidative stress dependent manner. In the present study, we aimed to investigate the role of transcription factor (TF) AP-1 on the NOS-3 deregulation during GCDCA-induced cholestasis. The cytotoxic response to GCDCA was characterized by 1) the increased expression and activation of TFs cJun and c-Fos; 2) a higher binding capability of these at position -666 of the NOS-3 promoter; 3) a decrease of the transcriptional activity of the promoter and the expression and activity of NOS-3; and 4) the expression increase of cyclin D1. Specific inhibition of AP-1 by the retinoid SR 11302 counteracted the cytotoxic effects induced by GCDCA while promoting NOS-3 expression recovery and cyclin D1 reduction. NOS activity inhibition by L-NAME inhibited the protective effect of SR 11302. Inducible NOS isoform was no detected in this experimental model of cholestasis. Our data provide direct evidence for the involvement of AP-1 in the NOS-3 expression regulation during cholestasis and define a critical role for NOS-3 in regulating the expression of cyclin D1 during the cell damage induced by bile acids. AP-1 appears as a potential therapeutic target in cholestatic liver diseases given its role as a transcriptional repressor of NOS-3. PMID:27490694

  9. Spergularia marina Induces Glucagon-Like Peptide-1 Secretion in NCI-H716 Cells Through Bile Acid Receptor Activation

    PubMed Central

    Kim, Kyong; Lee, Yu Mi; Rhyu, Mee-Ra

    2014-01-01

    Abstract Spergularia marina Griseb. (SM) is a halophyte that grows in mud flats. The aerial portions of SM have been eaten as vegetables and traditionally used to prevent chronic diseases in Korea. However, there has been no scientific report that demonstrates the pharmacological effects of SM. Glucagon-like peptide-1 (GLP-1) is important for the maintenance of glucose and energy homeostasis through acting as a signal in peripheral and neural systems. To discover a functional food for regulating glucose and energy homeostasis, we evaluated the effect of an aqueous ethanolic extract (AEE) of SM on GLP-1 release from enteroendocrine NCI-H716 cells. In addition, we explored the Takeda G-protein-coupled receptor 5 (TGR5) agonist activity of AEE-SM in Chinese hamster ovary (CHO)-K1 cells transiently transfected with human TGR5. As a result, treatment of NCI-H716 cells with AEE-SM increased GLP-1 secretion and intracellular Ca2+ and cyclic AMP (cAMP) levels in a dose-dependent manner. Transfection of NCI-H716 cells with TGR5-specific small interference RNA inhibited AEE-SM-induced GLP-1 secretion and the increase in Ca2+ and cAMP levels. Moreover, AEE-SM showed that the TGR5 agonist activity in CHO-K1 cells transiently transfected with TGR5. The results suggest that AEE-SM might be a candidate for a functional food to regulate glucose and energy homeostasis. PMID:25260089

  10. Enterococcus faecalis inhibits superantigen toxic shock syndrome toxin-1-induced interleukin-8 from human vaginal epithelial cells through tetramic acids.

    PubMed

    Brosnahan, Amanda J; Merriman, Joseph A; Salgado-Pabón, Wilmara; Ford, Bradley; Schlievert, Patrick M

    2013-01-01

    The vaginal mucosa can be colonized by many bacteria including commensal organisms and potential pathogens, such as Staphylococcus aureus. Some strains of S. aureus produce the superantigen toxic shock syndrome toxin-1, which can penetrate the vaginal epithelium to cause toxic shock syndrome. We have observed that a female was mono-colonized with Enterococcus faecalis vaginally as tested in aerobic culture, even upon repeated culture for six months, suggesting this organism was negatively influencing colonization by other bacteria. In recent studies, we demonstrated an "outside-in" mechanism of cytokine signaling and consequent inflammation that facilitates the ability of potential pathogens to initiate infection from mucosal surfaces. Thus, we hypothesized that this strain of E. faecalis may make anti-inflammatory factors which block disease progression of more pathogenic organisms. E. faecalis MN1 inhibited interleukin-8 production from human vaginal epithelial cells in response to the vaginal pathogens Candida albicans, Gardnerella vaginalis, and Neisseria gonorrhoeae, as well as to toxic shock syndrome toxin-1. We further demonstrated that this organism secretes two tetramic acid compounds which appear responsible for inhibition of interleukin-8 production, as well as inhibition of T cell proliferation due to toxic shock syndrome toxin-1. Microbicides that include anti-inflammatory molecules, such as these tetramic acid compounds naturally produced by E. faecalis MN1, may be useful in prevention of diseases that develop from vaginal infections. PMID:23613823

  11. Clearance of protoporphyrin IX induced by 5-aminolevulinic acid from WiDr human colon carcinoma cells

    NASA Astrophysics Data System (ADS)

    Juzeniene, Asta; Kaliszewski, Miron; Bugaj, Andrzej; Moan, Johan

    2009-06-01

    5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) is the most widely practiced form of PDT in dermatology. One of the advantages of ALA-PDT is that undesirable photosensitization lasts only for 24-48 h. In order to optimize ALA-PDT it is necessary to understand the mechanisms controlling intracellular PpIX clearance (efflux and transformation into heme) in order to decrease protoporphyrin IX (PpIX) clearance rates in the early stages of its production. The aim of this study was to investigate the factors controlling the clearance of intracellular PpIX. Fluorescence spectroscopy was used to study PpIX kinetics in WiDr cells initially treated with ALA. The clearance rate of PpIX in WiDr cells was faster after application of a low concentration of ALA (0.1 mM) than after application of high concentration of ALA (1 mM). PpIX was cleared faster from cells which initially were seeded at low densities than cells seeded at higher densities. The presence of the iron chelator deferoxamine reduced the clearance rate of PpIX, while the presence of ferrous sulfate acted oppositely. The decay rate of PpIX in WiDr cells was faster at higher temperature than at lower. The ferrochelatase activity at pH 7.2 was significantly greater than that at pH 6.7. ALA concentration, application time, cell density, temperature, pH, intracellular iron content, intracellular amount and localization of PpIX are factors controlling PpIX clearance.

  12. Boric acid induces cytoplasmic stress granule formation, eIF2α phosphorylation, and ATF4 in prostate DU-145 cells.

    PubMed

    Henderson, Kimberly A; Kobylewski, Sarah E; Yamada, Kristin E; Eckhert, Curtis D

    2015-02-01

    Dietary boron intake is associated with reduced prostate and lung cancer risk and increased bone mass. Boron is absorbed and circulated as boric acid (BA) and at physiological concentrations is a reversible competitive inhibitor of cyclic ADP ribose, the endogenous agonist of the ryanodine receptor calcium (Ca(+2)) channel, and lowers endoplasmic reticulum (ER) [Ca(2+)]. Low ER [Ca(2+)] has been reported to induce ER stress and activate the eIF2α/ATF4 pathway. Here we report that treatment of DU-145 prostate cells with physiological levels of BA induces ER stress with the formation of stress granules and mild activation of eIF2α, GRP78/BiP, and ATF4. Mild activation of eIF2α and its downstream transcription factor, ATF4, enables cells to reconfigure gene expression to manage stress conditions and mild activation of ATF4 is also required for the differentiation of osteoblast cells. Our results using physiological levels of boric acid identify the eIF2α/ATF pathway as a plausible mode of action that underpins the reported health effects of dietary boron. PMID:25425213

  13. Cells Deficient in the Fanconi Anemia Protein FANCD2 are Hypersensitive to the Cytotoxicity and DNA Damage Induced by Coffee and Caffeic Acid.

    PubMed

    Burgos-Morón, Estefanía; Calderón-Montaño, José Manuel; Orta, Manuel Luis; Guillén-Mancina, Emilio; Mateos, Santiago; López-Lázaro, Miguel

    2016-01-01

    Epidemiological studies have found a positive association between coffee consumption and a lower risk of cardiovascular disorders, some cancers, diabetes, Parkinson and Alzheimer disease. Coffee consumption, however, has also been linked to an increased risk of developing some types of cancer, including bladder cancer in adults and leukemia in children of mothers who drink coffee during pregnancy. Since cancer is driven by the accumulation of DNA alterations, the ability of the coffee constituent caffeic acid to induce DNA damage in cells may play a role in the carcinogenic potential of this beverage. This carcinogenic potential may be exacerbated in cells with DNA repair defects. People with the genetic disease Fanconi Anemia have DNA repair deficiencies and are predisposed to several cancers, particularly acute myeloid leukemia. Defects in the DNA repair protein Fanconi Anemia D2 (FANCD2) also play an important role in the development of a variety of cancers (e.g., bladder cancer) in people without this genetic disease. This communication shows that cells deficient in FANCD2 are hypersensitive to the cytotoxicity (clonogenic assay) and DNA damage (γ-H2AX and 53BP1 focus assay) induced by caffeic acid and by a commercial lyophilized coffee extract. These data suggest that people with Fanconi Anemia, or healthy people who develop sporadic mutations in FANCD2, may be hypersensitive to the carcinogenic activity of coffee. PMID:27399778

  14. Cells Deficient in the Fanconi Anemia Protein FANCD2 are Hypersensitive to the Cytotoxicity and DNA Damage Induced by Coffee and Caffeic Acid

    PubMed Central

    Burgos-Morón, Estefanía; Calderón-Montaño, José Manuel; Orta, Manuel Luis; Guillén-Mancina, Emilio; Mateos, Santiago; López-Lázaro, Miguel

    2016-01-01

    Epidemiological studies have found a positive association between coffee consumption and a lower risk of cardiovascular disorders, some cancers, diabetes, Parkinson and Alzheimer disease. Coffee consumption, however, has also been linked to an increased risk of developing some types of cancer, including bladder cancer in adults and leukemia in children of mothers who drink coffee during pregnancy. Since cancer is driven by the accumulation of DNA alterations, the ability of the coffee constituent caffeic acid to induce DNA damage in cells may play a role in the carcinogenic potential of this beverage. This carcinogenic potential may be exacerbated in cells with DNA repair defects. People with the genetic disease Fanconi Anemia have DNA repair deficiencies and are predisposed to several cancers, particularly acute myeloid leukemia. Defects in the DNA repair protein Fanconi Anemia D2 (FANCD2) also play an important role in the development of a variety of cancers (e.g., bladder cancer) in people without this genetic disease. This communication shows that cells deficient in FANCD2 are hypersensitive to the cytotoxicity (clonogenic assay) and DNA damage (γ-H2AX and 53BP1 focus assay) induced by caffeic acid and by a commercial lyophilized coffee extract. These data suggest that people with Fanconi Anemia, or healthy people who develop sporadic mutations in FANCD2, may be hypersensitive to the carcinogenic activity of coffee. PMID:27399778

  15. Synergism of ursolic acid derivative US597 with 2-deoxy-D-glucose to preferentially induce tumor cell death by dual-targeting of apoptosis and glycolysis.

    PubMed

    Wang, Jichuang; Jiang, Zhou; Xiang, Liping; Li, Yuanfang; Ou, Minrui; Yang, Xiang; Shao, Jingwei; Lu, Yusheng; Lin, Lifeng; Chen, Jianzhong; Dai, Yun; Jia, Lee

    2014-01-01

    Ursolic acid (UA) is a naturally bioactive product that exhibits potential anticancer effects. The relatively safe and effective molecule intrigued us to explore a way to further improve its anti-cancer activity and tumor-targeting specificity. In the present study, a series of structural modifications of UA was achieved, which resulted in significant increase in growth inhibition on various cancer cell lines with minimal effects on normal cells. The leading molecule US597 (UA-4) caused depolarization of mitochondrial membrane potential, cell arrest in G0/G1 phase and apoptosis/necrosis in a dose-dependent manner. Structural docking suggested that the carbon chains of the modified UA derivatives compete strongly with glucose for binding to glucokinase, the key glycolysis enzyme presumably active in cancer cells. The combination of 2-deoxy-D-glucose (2-DG) and UA-4 induced cell cycle arrest in G2/M phase, promoted caspase-dependent cell death, reduced hexokinase activity, aggravated depletion of intracellular ATP, decreased lactate production and synergistically inhibited cancer cell growth in vitro (HepG2) and in vivo (H22). Collectively, our findings suggest that the structural modification enhances efficacy and selectivity of UA, and the combination of UA-4 with 2-DG produces synergistic inhibition on hepatoma cell proliferation by dual targeting of apoptosis and glycolysis. PMID:25833312

  16. Schwann cell proliferation and differentiation that is induced by ferulic acid through MEK1/ERK1/2 signalling promotes peripheral nerve remyelination following crush injury in rats

    PubMed Central

    Zhu, Xiaoyan; Li, Kun; Guo, Xin; Wang, Jian; Xiang, Yang

    2016-01-01

    Schwann cell proliferation and differentiation is critical for the remyelination of injured peripheral nerves. Ferulic acid (FA) is a widely used antioxidant agent with neuroprotective properties. However, the potentially beneficial effects of FA on Schwann cells are unknown. Therefore, the present study was designed to examine the effects of FA on Schwann cell proliferation and differentiation. By using the cultured primary Schwann cells and proliferation assay, the results identified that FA was capable of increasing Schwann cell proliferation and expression of myelin-associated glycoprotein (MAG) and myelin basic protein (MBP) in vitro. It was also observed that the beneficial effect of FA treatment on Schwann cells was mainly dependent on the activation of MEK1/ERK1/2 signalling. Furthermore, FA was intraperitoneally administered to rats with sciatic nerve crush injury, and the results revealed an increase in Schwann cell proliferation and differentiation, while the MAG and MBP expression levels in sciatic nerves were markedly upregulated following FA administration. In conclusion, the current results demonstrate that Schwann cell proliferation and differentiation is induced by FA through MEK1/ERK1/2 signalling and that FA may accelerate injured peripheral nerve remyelination.

  17. Human cutaneous fatty acid-binding protein induces metastasis by up-regulating the expression of vascular endothelial growth factor gene in rat Rama 37 model cells.

    PubMed

    Jing, C; Beesley, C; Foster, C S; Chen, H; Rudland, P S; West, D C; Fujii, H; Smith, P H; Ke, Y

    2001-06-01

    Human cutaneous fatty acid-binding protein (C-FABP) gene is capable of inducing the metastatic phenotype when overexpressed in nonmetastatic rat Rama 37 cells. However, the mechanism of how it induces metastasis is not clear. Northern and slot blot analyses revealed that expression of the endogenous vascular endothelial growth factor (VEGF) gene was increased by 3.8-5.2-fold in the C-FABP-transfected cells (pSV-CFABP-R37) and in their metastatic sublines (e.g., Met-1) when compared with that in the nonmetastatic control transfectant pSV-R37 cells generated by transfection of only plasmid DNA. Higher levels of VEGF immunoreactive protein were also secreted from the malignant C-FABP-expressing cells. Reverse transcription-PCR detected two VEGF transcript isoforms, VEGF(164) and VEGF(188), in both the nonmetastatic control transfectant pSV-R37 cells and the malignant metastatic Met-1 cells. Chick chorioallantoic membrane assays showed that the conditioned medium of the control pSV-R37 cells possessed only very weak angiogenic activity, whereas conditioned media from the metastatic C-FABP transfectants and their sublines were strongly angiogenic and could be inhibited by antibodies to VEGF. Transfection of VEGF(164) cDNA in an expression vector into nonmetastatic Rama 37 cells produced a cell clone (R37-VEGF-2) that expressed high levels of VEGF. Inoculation of R37-VEGF-2 cells into syngeneic Wistar Furth rats produced metastases in a significant number (Fisher's exact test, P < 0.01) of animals (18 of 31 animals), whereas the control, vector alone-transfected R37-PSV cells produced no metastases (0 of 30 animals). Immunocytochemical methods demonstrated a strong positive staining for VEGF and an increased microvessel density in the primary tumors produced from PSV-VEGF-2 cells in comparison with tumors produced from control transfectants. Immunocytochemical staining for factor VIII detected a 3.5-fold increase in microvessel density of the primary tumors produced by

  18. Rosmarinic Acid Attenuates Cell Damage against UVB Radiation-Induced Oxidative Stress via Enhancing Antioxidant Effects in Human HaCaT Cells

    PubMed Central

    Fernando, Pattage Madushan Dilhara Jayatissa; Piao, Mei Jing; Kang, Kyoung Ah; Ryu, Yea Seong; Hewage, Susara Ruwan Kumara Madduma; Chae, Sung Wook; Hyun, Jin Won

    2016-01-01

    This study was designed to investigate the cytoprotective effect of rosmarinic acid (RA) on ultraviolet B (UVB)-induced oxidative stress in HaCaT keratinocytes. RA exerted a significant cytoprotective effect by scavenging intracellular ROS induced by UVB. RA also attenuated UVB-induced oxidative macromolecular damage, including protein carbonyl content, DNA strand breaks, and the level of 8-isoprostane. Furthermore, RA increased the expression and activity of superoxide dismutase, catalase, heme oxygenase-1, and their transcription factor Nrf2, which are decreased by UVB radiation. Collectively, these data indicate that RA can provide substantial cytoprotection against the adverse effects of UVB radiation by modulating cellular antioxidant systems, and has potential to be developed as a medical agent for ROS-induced skin diseases. PMID:26759705

  19. Chlorogenic acid improves ex vivo vessel function and protects endothelial cells against HOCl-induced oxidative damage, via increased production of nitric oxide and induction of Hmox-1.

    PubMed

    Jiang, Rujia; Hodgson, Jonathan M; Mas, Emilie; Croft, Kevin D; Ward, Natalie C

    2016-01-01

    Dietary polyphenols are potential contributors toward improved cardiovascular health. Coffee is one of the richest sources of dietary polyphenols in a coffee-drinking population, the most abundant form being chlorogenic acid (CGA). Endothelial dysfunction is an early and major risk factor for cardiovascular disease. Nitric oxide (NO) is a key factor in regulation of endothelial function. Heme oxygenase-1 (Hmox-1), an inducible isoform of heme oxygenase that is produced in response to stressors such as oxidative stress, may also play a role in vascular protection. The aim of this study was to investigate the effect of CGA on endothelial function with oxidant-induced damage in isolated aortic rings from C57BL mice. We further examine the mechanism by investigating cell viability, activation of eNOS and induction of Hmox-1 in human aortic endothelial cells (HAECs). We found that pretreatment of isolated aortic rings with 10-μM CGA-protected vessels against HOCl-induced endothelial dysfunction (P<0.05). Pretreatment of cultured HAECs with 10-μM CGA increased endothelial cell viability following exposure to HOCl (P<0.05). Moreover, CGA increased NO production in HAECs in a dose-dependent manner, peaking at 6 h (P<0.05). CGA at 5 μM and 10 μM increased eNOS dimerization at 6 h and induced Hmox-1 protein expression at 6 h and 24 h in HAECs. These results are consistent with the cardiovascular protective effects of coffee polyphenols and demonstrate that CGA can protect vessels and cultured endothelial cells against oxidant-induced damage. The mechanism behind the beneficial effect of CGA appears to be in part via increased production of NO and induction of Hmox-1. PMID:26386740

  20. Induction of autophagy is a key component of all-trans-retinoic acid-induced differentiation in leukemia cells and a potential target for pharmacologic modulation.

    PubMed

    Orfali, Nina; O'Donovan, Tracey R; Nyhan, Michelle J; Britschgi, Adrian; Tschan, Mario P; Cahill, Mary R; Mongan, Nigel P; Gudas, Lorraine J; McKenna, Sharon L

    2015-09-01

    Acute myeloid leukemia (AML) is characterized by the accumulation of immature blood cell precursors in the bone marrow. Pharmacologically overcoming the differentiation block in this condition is an attractive therapeutic avenue, which has achieved success only in a subtype of AML, acute promyelocytic leukemia (APL). Attempts to emulate this success in other AML subtypes have thus far been unsuccessful. Autophagy is a conserved protein degradation pathway with important roles in mammalian cell differentiation, particularly within the hematopoietic system. In the study described here, we investigated the functional importance of autophagy in APL cell differentiation. We found that autophagy is increased during all-trans-retinoic acid (ATRA)-induced granulocytic differentiation of the APL cell line NB4 and that this is associated with increased expression of LC3II and GATE-16 proteins involved in autophagosome formation. Autophagy inhibition, using either drugs (chloroquine/3-methyladenine) or short-hairpin RNA targeting the essential autophagy gene ATG7, attenuates myeloid differentiation. Importantly, we found that enhancing autophagy promotes ATRA-induced granulocytic differentiation of an ATRA-resistant derivative of the non-APL AML HL60 cell line (HL60-Diff-R). These data support the development of strategies to stimulate autophagy as a novel approach to promote differentiation in AML. PMID:25986473

  1. c-myc regulation during retinoic acid-induced differentiation of F9 cells is posttranscriptional and associated with growth arrest.

    PubMed Central

    Dean, M; Levine, R A; Campisi, J

    1986-01-01

    We have shown that c-myc mRNA levels decrease more than 20-fold when F9 teratocarcinoma stem cells are induced to arrest growth and terminally differentiate to parietal endoderm after exposure to retinoic acid and cyclic AMP (Campisi et al., Cell 36:241-247, 1984). Here, we demonstrate that although growth arrest and full expression of the differentiated phenotype required about 3 days, c-myc mRNA declined abruptly between 8 and 16 h after the addition of retinoic acid and cyclic AMP. The decline was independent of cyclic AMP. We found little or no change in the level of c-myc transcription during differentiation, although two other genes showed marked transcriptional regulation. Thus, decreased c-myc mRNA is a consequence of very early posttranscriptional regulation directed by retinoic acid. Differentiation was not fundamental to this regulation. We have shown that sodium butyrate blocks expression of the differentiated phenotype if added within 8 h of retinoic acid and cyclic AMP (Levine et al., Dev. Biol. 105:443-450, 1984). However, butyrate did not inhibit the decrease in c-myc mRNA. Furthermore, F9 cells partially arrested growth without differentiating when grown in isoleucine-deficient medium. Under these conditions, c-myc mRNA levels also declined. Our results suggest that induction of differentiation-specific genes may be under retinoic acid-mediated control dissimilar from that responsible for the decay of c-myc mRNA. In addition, they raise the possibility that growth arrest may be initiated by reduced c-myc expression. Images PMID:3785153

  2. Arabidopsis abi1-1 and abi2-1 phosphatase mutations reduce abscisic acid-induced cytoplasmic calcium rises in guard cells.

    PubMed

    Allen, G J; Kuchitsu, K; Chu, S P; Murata, Y; Schroeder, J I

    1999-09-01

    Elevations in cytoplasmic calcium ([Ca(2)+](cyt)) are an important component of early abscisic acid (ABA) signal transduction. To determine whether defined mutations in ABA signal transduction affect [Ca(2)+](cyt) signaling, the Ca(2)+-sensitive fluorescent dye fura 2 was loaded into the cytoplasm of Arabidopsis guard cells. Oscillations in [Ca(2)+](cyt) could be induced when the external calcium concentration was increased, showing viable Ca(2)+ homeostasis in these dye-loaded cells. ABA-induced [Ca(2)+](cyt) elevations in wild-type stomata were either transient or sustained, with a mean increase of approximately 300 nM. Interestingly, ABA-induced [Ca(2)+](cyt) increases were significantly reduced but not abolished in guard cells of the ABA-insensitive protein phosphatase mutants abi1 and abi2. Plasma membrane slow anion currents were activated in wild-type, abi1, and abi2 guard cell protoplasts by increasing [Ca(2)+](cyt), demonstrating that the impairment in ABA activation of anion currents in the abi1 and abi2 mutants was bypassed by increasing [Ca(2)+](cyt). Furthermore, increases in external calcium alone (which elevate [Ca(2)+](cyt)) resulted in stomatal closing to the same extent in the abi1 and abi2 mutants as in the wild type. Conversely, stomatal opening assays indicated different interactions of abi1 and abi2, with Ca(2)+-dependent signal transduction pathways controlling stomatal closing versus stomatal opening. Together, [Ca(2)+](cyt) recordings, anion current activation, and stomatal closing assays demonstrate that the abi1 and abi2 mutations impair early ABA signaling events in guard cells upstream or close to ABA-induced [Ca(2)+](cyt) elevations. These results further demonstrate that the mutations can be bypassed during anion channel activation and stomatal closing by experimental elevation of [Ca(2)+](cyt). PMID:10488243

  3. Retinoic Acid Receptors Control Spermatogonia Cell-Fate and Induce Expression of the SALL4A Transcription Factor.

    PubMed

    Gely-Pernot, Aurore; Raverdeau, Mathilde; Teletin, Marius; Vernet, Nadège; Féret, Betty; Klopfenstein, Muriel; Dennefeld, Christine; Davidson, Irwin; Benoit, Gérard; Mark, Manuel; Ghyselinck, Norbert B

    2015-10-01

    All-trans retinoic acid (ATRA) is instrumental to male germ cell differentiation, but its mechanism of action remains elusive. To address this question, we have analyzed the phenotypes of mice lacking, in spermatogonia, all rexinoid receptors (RXRA, RXRB and RXRG) or all ATRA receptors (RARA, RARB and RARG). We demonstrate that the combined ablation of RXRA and RXRB in spermatogonia recapitulates the set of defects observed both upon ablation of RAR in spermatogonia. We also show that ATRA activates RAR and RXR bound to a conserved regulatory region to increase expression of the SALL4A transcription factor in spermatogonia. Our results reveal that this major pluripotency gene is a target of ATRA signaling and that RAR/RXR heterodimers are the functional units driving its expression in spermatogonia. They add to the mechanisms through which ATRA promote expression of the KIT tyrosine kinase receptor to trigger a critical step in spermatogonia differentiation. Importantly, they indicate also that meiosis eventually occurs in the absence of a RAR/RXR pathway within germ cells and suggest that instructing this process is either ATRA-independent or requires an ATRA signal originating from Sertoli cells. PMID:26427057

  4. Retinoic Acid Receptors Control Spermatogonia Cell-Fate and Induce Expression of the SALL4A Transcription Factor

    PubMed Central

    Gely-Pernot, Aurore; Raverdeau, Mathilde; Teletin, Marius; Vernet, Nadège; Féret, Betty; Klopfenstein, Muriel; Dennefeld, Christine; Davidson, Irwin; Benoit, Gérard; Mark, Manuel; Ghyselinck, Norbert B.

    2015-01-01

    All-trans retinoic acid (ATRA) is instrumental to male germ cell differentiation, but its mechanism of action remains elusive. To address this question, we have analyzed the phenotypes of mice lacking, in spermatogonia, all rexinoid receptors (RXRA, RXRB and RXRG) or all ATRA receptors (RARA, RARB and RARG). We demonstrate that the combined ablation of RXRA and RXRB in spermatogonia recapitulates the set of defects observed both upon ablation of RAR in spermatogonia. We also show that ATRA activates RAR and RXR bound to a conserved regulatory region to increase expression of the SALL4A transcription factor in spermatogonia. Our results reveal that this major pluripotency gene is a target of ATRA signaling and that RAR/RXR heterodimers are the functional units driving its expression in spermatogonia. They add to the mechanisms through which ATRA promote expression of the KIT tyrosine kinase receptor to trigger a critical step in spermatogonia differentiation. Importantly, they indicate also that meiosis eventually occurs in the absence of a RAR/RXR pathway within germ cells and suggest that instructing this process is either ATRA-independent or requires an ATRA signal originating from Sertoli cells. PMID:26427057

  5. Artemisinic Acid Serves as a Novel ORCA3 Inducer to Enhance Biosynthesis of Terpenoid Indole Alkaloids in Catharanthus roseus Cambial Meristematic Cells.

    PubMed

    Wang, Mingxuan; Zi, Jiachen; Zhu, Jianhua; Chen, Shan; Wang, Pu; Song, Liyan; Yu, Rongmin

    2016-06-01

    To investigate the effect of artemisinic acid (AA) on improving the production of terpenoid indole alkaloids (TIAs) of Catharanthus roseus cambial meristematic cells (CMCs), feeding AA to C. roseus CMCs caused 2.35-fold and 2.51-fold increases in the production of vindoline and catharanthine, respectively, compared with those of the untreated CMCs. qRT-PCR experiments showed that AA resulted in a 1.36-8.52 fold increase in the transcript levels of several related genes, including octadecanoid-derivative responsive Catharanthus AP2-domain protein 3 (ORCA3), tryptophan decarboxylase (TDC), strictosidine synthase (STR) and desacetoxyvindoline 4-hydroxylase (D4H). However, no effect was observed on the concentration of either jasmonic acid (JA), or the octadecanoid-pathway inhibitors block TIA accumulation caused by AA. The results indicated that AA might serve as a novel ORCA3 inducer to manipulate biosynthesis of TIAs in C. roseus CMCs via an unknown mechanism. PMID:27534099

  6. Menopause-induced uterine epithelium atrophy results from arachidonic acid/prostaglandin E2 axis inhibition-mediated autophagic cell death

    PubMed Central

    Zhou, Shengtao; Zhao, Linjie; Yi, Tao; Wei, Yuquan; Zhao, Xia

    2016-01-01

    Women experience menopause later in life. Menopause is characterized by dramatically decreased circulating estrogen level secondary to loss of ovarian function and atrophic state of genital organs. However, the molecular mechanisms for this process are not fully understood. In this study, we aimed to investigate the potential molecular mechanisms that underlie menopause-induced uterine endometrial atrophy. Our data showed that autophagy was activated in the uterine epithelial cells of both ovariectomized rats and peri-menopausal females. Endoplasmic reticulum (ER) stress occurred even prior to autophagy induction. Integrated bioinformatics analysis revealed that ER stress induced downstream decreased release of arachidonic acid (AA) and downregulation of AA/prostaglandin E2 (PGE2) axis, which led to Akt/mTOR signaling pathway inactivation. Consequently, autophagosomes were recruited and LC3-dependent autophagy was induced in uterine epithelial cells. Treatment with exogenous E2, PGE2, salubrinal or RNAi-mediated silencing of key autophagy genes could effectively counteract estrogen depletion-induced autophagy. Collectively, autophagy is a critical regulator of the uterine epithelium that accounts for endometrial atrophy after menopause. PMID:27506466

  7. Menopause-induced uterine epithelium atrophy results from arachidonic acid/prostaglandin E2 axis inhibition-mediated autophagic cell death.

    PubMed

    Zhou, Shengtao; Zhao, Linjie; Yi, Tao; Wei, Yuquan; Zhao, Xia

    2016-01-01

    Women experience menopause later in life. Menopause is characterized by dramatically decreased circulating estrogen level secondary to loss of ovarian function and atrophic state of genital organs. However, the molecular mechanisms for this process are not fully understood. In this study, we aimed to investigate the potential molecular mechanisms that underlie menopause-induced uterine endometrial atrophy. Our data showed that autophagy was activated in the uterine epithelial cells of both ovariectomized rats and peri-menopausal females. Endoplasmic reticulum (ER) stress occurred even prior to autophagy induction. Integrated bioinformatics analysis revealed that ER stress induced downstream decreased release of arachidonic acid (AA) and downregulation of AA/prostaglandin E2 (PGE2) axis, which led to Akt/mTOR signaling pathway inactivation. Consequently, autophagosomes were recruited and LC3-dependent autophagy was induced in uterine epithelial cells. Treatment with exogenous E2, PGE2, salubrinal or RNAi-mediated silencing of key autophagy genes could effectively counteract estrogen depletion-induced autophagy. Collectively, autophagy is a critical regulator of the uterine epithelium that accounts for endometrial atrophy after menopause. PMID:27506466

  8. The Protective Effects of Isoliquiritigenin and Glycyrrhetinic Acid against Triptolide-Induced Oxidative Stress in HepG2 Cells Involve Nrf2 Activation

    PubMed Central

    Cao, Ling-Juan; Li, Huan-De; Yan, Miao; Li, Zhi-Hua; Gong, Hui; Jiang, Pei; Deng, Yang; Fang, Ping-Fei; Zhang, Bi-Kui

    2016-01-01

    Triptolide (TP), an active ingredient of Tripterygium wilfordii Hook f., possesses a wide range of biological activities. Oxidative stress likely plays a role in TP-induced hepatotoxicity. Isoliquiritigenin (ISL) and glycyrrhetinic acid (GA) are potent hepatoprotection agents. The aim of the present study was to investigate whether Nrf2 pathway is associated with the protective effects of ISL and GA against TP-induced oxidative stress or not. HepG2 cells were treated with TP (50 nM) for 24 h after pretreatment with ISL and GA (5, 10, and 20 μM) for 12 h and 24 h, respectively. The results demonstrated that TP treatment significantly increased ROS levels and decreased GSH levels. Both ISL and GA pretreatment decreased ROS and meanwhile enhanced intracellular GSH content. Additionally, TP treatment obviously decreased the protein expression of Nrf2 and its target genes including HO-1 and MRP2 except NQO1. Moreover, both ISL and GA displayed activities as inducers of Nrf2 and increased the expression of HO-1, NQO1, and MRP2. Taken together the current data confirmed that ISL and GA could activate the Nrf2 antioxidant response in HepG2 cells, increasing the expression of its target genes which may be partly associated with their protective effects in TP-induced oxidative stress. PMID:26904149

  9. ROS-Mediated Autophagy Induced by Dysregulation of Lipid Metabolism Plays a Protective Role in Colorectal Cancer Cells Treated with Gambogic Acid

    PubMed Central

    Zhang, Haiyuan; Lei, Yunlong; Yuan, Ping; Li, Lingjun; Luo, Chao; Gao, Rui; Tian, Jun; Feng, Zuohua; Nice, Edouard C.; Sun, Jun

    2014-01-01

    Gambogic acid (GA), the main active component of gamboge resin, has potent antitumor activity both in vivo and in vitro. However, the underlying molecular mechanisms remain unclear. In this study, we found that GA could initiate autophagy in colorectal cancer cells, and inhibition of the autophagy process accelerated the effect of proliferative inhibition and apoptotic cell death induced by GA, implying a protective role of autophagy. Two-dimensional electrophoresis-based proteomics showed that GA treatment altered the expression of multiple proteins involved in redox signaling and lipid metabolism. Functional studies revealed that GA-induced dysregulation of lipid metabolism could activate 5-lipoxygenase (5-LOX), resulting in intracellular ROS accumulation, followed by inhibition of Akt-mTOR signaling and autophagy initiation. Finally, results using a xenograft model suggested ROS-induced autophagy protect against the antitumor effect of GA. Taken together, these data showed new biological activities of GA against colorectal cancer underlying the protective role of ROS-induced autophagy. This study will provide valuable insights for future studies regarding the anticancer mechanisms of GA. PMID:24810758

  10. Treadmill exercise improves short-term memory by enhancing hippocampal cell proliferation in quinolinic acid-induced Huntington’s disease rats

    PubMed Central

    Kim, You-Mi; Ji, Eun-Sang; Kim, Sang-Hoon; Kim, Tae-Woon; Ko, Il-Gyu; Jin, Jun-Jang; Kim, Chang-Ju; Kim, Tae-Wook; Kim, Dong-Hee

    2015-01-01

    Huntington’s disease (HD) is an inherited genetic disorder, characterized by cognitive dysfunction and abnormal body movements called chorea. Quinolinic acid (QA) is an endogenous metabolite of tryptophan in the kynurenine pathway. QA-induced alterations are similar to the symptoms of HD patients. Physical exercise has beneficial effects on the brain functions. Exercise increases production of neurotrophic factors in the brain and improves learning ability and memory function. In the present study, we investigated the effects of treadmill exercise short-term memory on QA-induced HD rats in relation with cell proliferation. For the induction of Huntington’s animal model, 2 μL of 100 nmol QA was intrastriatal injected into the rats. The rats in the treadmill exercise groups were forced to run on a treadmill for 30 min once a day, five times a week for 2 weeks. Step-down avoidance test was conducted for the determination of short-term memory. Cell proliferation in the hippocampal dentate gyrus was determined by 5-bromo-2′-deoxyuridine (BrdU) and doublecortin (DCX) immunohistochemistry. Western blot for brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) were performed. In the present results, treadmill exercise alleviated QA-induced short-term memory impairment in HD rats. Treadmill exercise increased cell proliferation in the hippocampal dentate gyrus through enhancing BDNF expression in the HD rats. These results revealed that treadmill exercise is effective for the symptom improvement in the HD patients. PMID:25830138

  11. Valproic Acid Enhances iPSC Induction From Human Bone Marrow-Derived Cells Through the Suppression of Reprogramming-Induced Senescence.

    PubMed

    Chen, Xi; Zhai, Yingying; Yu, Dehai; Cui, Jiuwei; Hu, Ji-Fan; Li, Wei

    2016-08-01

    Reprogramming of human somatic cells into pluripotent cells (iPSCs) by defined transcription factors is an extremely inefficient process. Treatment with the histone deacetylase inhibitor valproic acid (VPA) during reprogramming can improve the induction of iPSCs. To examine the specific mechanism underlying the role of VPA in reprogramming, we transfected human bone marrow-derived cells (HSC-J2 and HSC-L1) with lentiviruses carrying defined factors (OCT4, SOX2, KLF4, and c-MYC, OSKM) in the presence of VPA. We found that, OSKM lentiviruses caused significant senescence in transfected cells. Administration of VPA, however, significantly suppressed this reprogramming-induced stress. Notably, VPA treatment improved cell proliferation in the early stages of reprogramming, and this was related to the down-regulation of the activated p16/p21 pathway. In addition, VPA also released the G2/M phase blockade in lentivirus-transfected cells. This study demonstrates a new mechanistic role of the histone deacetylase inhibitor in enhancing the induction of pluripotency. J. Cell. Physiol. 231: 1719-1727, 2016. © 2015 Wiley Periodicals, Inc. PMID:26620855

  12. Exposure to the polyester PET precursor—terephthalic acid induces and perpetuates DNA damage-harboring non-malignant human breast cells

    PubMed Central

    Luciani-Torres, Maria Gloria; Moore, Dan H.; Dairkee, Shanaz H.

    2015-01-01

    Identification of early perturbations induced in cells from non-cancerous breast tissue is critical for understanding possible breast cancer risk from chemical exposure. We have demonstrated previously that exposure to the ubiquitous xenoestrogens, bisphenol A (BPA) and methyl paraben, promotes the hallmarks of cancer in non-malignant human high-risk donor breast epithelial cells (HRBECs) isolated from several donors. Here we show that terephthalic acid (TPA), a major chemical precursor of polyethylene terephthalate (PET) containers used for the storage of food and beverages, increased the ERα: ERβ ratio in multiple HRBEC samples, suggesting an estrogenic effect. Although, like BPA and methyl paraben, TPA also promoted resistance to tamoxifen-induced apoptosis, unlike these chemicals instead of inducing an increased S-phase fraction, TPA treatment arrested cell proliferation. DNA-PK, ATM and members of the MRN complex, known to be involved in DNA damage sensor and effector proteins, were elevated indicating induction of DNA strand breaks. Early DNA damage checkpoint response, mediated through p53/p21, led to G1 arrest in TPA-exposed cells. Removal of TPA from the growth medium resulted in the rapid induction of BCL2, increasing the ratio of anti-: pro-apoptotic proteins, together with overexpression of Cyclin A/CDK2 proteins. Consequently, despite elevated p53pSer15 and H2AXpSer139, indicating sustained DNA damage, TPA exposed cells resumed robust growth rates seen prior to TPA exposure. The propensity for the perpetuation of DNA aberrations that activate DNA damage pathways in non-malignant breast cells justifies careful consideration of human exposure to TPA, particularly at vulnerable life stages. PMID:25411358

  13. Sulfur mustard-induced increase in intracellular free calcium level and arachidonic acid release from cell membrane

    SciTech Connect

    Ray, R.; Legere, R.H.; Majerus, B.J.; Petrali, J.P.

    1995-12-31

    The mechanism of action of the alkylating agent bis-(2-chloroethyl)sulfide (sulfur mustard, SM) was studied using the in thai vitro mouse neuroblastoma-rat glioma hybrid NG 108-1 S clonal p