Science.gov

Sample records for p38 dependent pathway

  1. The p38 SAPK pathway regulates the expression of the MMP-9 collagenase via AP-1-dependent promoter activation.

    PubMed

    Simon, C; Simon, M; Vucelic, G; Hicks, M J; Plinkert, P K; Koitschev, A; Zenner, H P

    2001-12-10

    The invasive phenotype of cancers critically depends on the expression of proteases such as the M(R) 92,000 type IV collagenase (MMP-9). Several growth factors and oncogenes were found to increase promoter activity and as a consequence protease expression. This frequently requires the activation of the transcription factor AP-1 by signal transduction cascades such as the ERK and JNK pathways. We have previously demonstrated that the tumor promoter TPA can induce MMP-9 expression via a third signaling cascade, the p38 pathway. Considering that TPA is a potent activator of AP-1, we hypothesized that this transcription factor might also be required for p38 pathway-dependent MMP-9 regulation. While dominant negative p38 and MKK-6 mutants reduced MMP-9 promoter activity in CAT assays, a construct encoding an activating mutation in the MKK-6 protein potently stimulated it. This was mediated via 144 bp of the 5'flanking region of the wild-type promoter, which contains an AP-1 site at -79. Both point mutations in this motif and the expression of a c-jun protein lacking its transactivation domain and therefore acting as a dominant negative AP-1 mutant abrogated MKK-6-dependent promoter stimulation. Finally SB 203580, a specific p38 pathway inhibitor, reduced MMP-9 expression/secretion and in vitro invasion of cancer cells. Thus, our results provide evidence that also the third SAPK/MAPK signaling cascade, the p38 signal transduction pathway, stimulates MMP-9 expression in an AP-1-dependent fashion. PMID:11716547

  2. Metabolic Respiration Induces AMPK- and Ire1p-Dependent Activation of the p38-Type HOG MAPK Pathway

    PubMed Central

    Adhikari, Hema; Cullen, Paul J.

    2014-01-01

    Evolutionarily conserved mitogen activated protein kinase (MAPK) pathways regulate the response to stress as well as cell differentiation. In Saccharomyces cerevisiae, growth in non-preferred carbon sources (like galactose) induces differentiation to the filamentous cell type through an extracellular-signal regulated kinase (ERK)-type MAPK pathway. The filamentous growth MAPK pathway shares components with a p38-type High Osmolarity Glycerol response (HOG) pathway, which regulates the response to changes in osmolarity. To determine the extent of functional overlap between the MAPK pathways, comparative RNA sequencing was performed, which uncovered an unexpected role for the HOG pathway in regulating the response to growth in galactose. The HOG pathway was induced during growth in galactose, which required the nutrient regulatory AMP-dependent protein kinase (AMPK) Snf1p, an intact respiratory chain, and a functional tricarboxylic acid (TCA) cycle. The unfolded protein response (UPR) kinase Ire1p was also required for HOG pathway activation in this context. Thus, the filamentous growth and HOG pathways are both active during growth in galactose. The two pathways redundantly promoted growth in galactose, but paradoxically, they also inhibited each other's activities. Such cross-modulation was critical to optimize the differentiation response. The human fungal pathogen Candida albicans showed a similar regulatory circuit. Thus, an evolutionarily conserved regulatory axis links metabolic respiration and AMPK to Ire1p, which regulates a differentiation response involving the modulated activity of ERK and p38 MAPK pathways. PMID:25356552

  3. Involvement of NF-κB-dependent signaling and p38 MAPK signaling pathway in the regulation of hemopoiesis during restrain stress.

    PubMed

    Dygai, A M; Zhdanov, V V; Zyuz'kov, G N; Udut, E V; Miroshnichenko, L A; Simanina, E V; Chaikovskii, A V; Stavrova, L A; Danilets, M G; Agafonov, V I; Khrichkova, T Yu

    2014-09-01

    Protein kinase p38 was shown to contribute to the increase in production of granulocyte CSF by microenvironmental cells under conditions of restraint stress. Stimulation of colony-forming activity was not accompanied by the increase in maturation of clonogenic structures in the bone marrow granulocytic stem. This process was realized with the involvement of NF-κB-dependent signaling and p38 MAPK signaling pathway. Our study showed that the p38 MAPK signaling pathway plays an important role in the regulation of granulocytopoiesis, but not of erythropoiesis. PMID:25257409

  4. β, β-Dimethylacrylshikonin induces mitochondria-dependent apoptosis of human lung adenocarcinoma cells in vitro via p38 pathway activation

    PubMed Central

    Wang, Hai-bing; Ma, Xiao-qiong

    2015-01-01

    Aim: β, β-Dimethylacrylshikonin (DMAS) is an anticancer compound extracted from the roots of Lithospermum erythrorhizon. In the present study, we investigated the effects of DMAS on human lung adenocarcinoma cells in vitro and explored the mechanisms of its anti-cancer action. Methods: Human lung adenocarcinoma A549 cells were tested. Cell viability was assessed using an MTT assay, and cell apoptosis was evaluated with flow cytometry and DAPI staining. The expression of the related proteins was detected using Western blotting. The mitochondrial membrane potential was measured using a JC-1 kit, and subcellular distribution of cytochrome c was analyzed using immunofluorescence staining. Results: Treatment of A549 cells with DMAS suppressed the cell viability in dose- and time-dependent manners (the IC50 value was 14.22 and 10.61 μmol/L, respectively, at 24 and 48 h). DMAS (7.5, 10, and 15 μmol/L) dose-dependently induced apoptosis, down-regulated cIAP-2 and XIAP expression, and up-regulated Bax and Bak expression in the cells. Furthermore, DMAS resulted in loss of mitochondrial membrane potential and release of cytochrome c in the cells, and activated caspase-9, caspase-8, and caspase-3, and subsequently cleaved PARP, which was abolished by pretreatment with Z-VAD-FMK, a pan-caspase inhibitor. DMAS induced sustained p38 phosphorylation in the cells, while pretreatment with SB203580, a specific p38 inhibitor, blocked DMAS-induced p38 activation and apoptosis. Conclusion: DMAS inhibits the growth of human lung adenocarcinoma A549 cells in vitro via activation of p38 signaling pathway. PMID:25434989

  5. SARS coronavirus papain-like protease induces Egr-1-dependent up-regulation of TGF-β1 via ROS/p38 MAPK/STAT3 pathway.

    PubMed

    Li, Shih-Wein; Wang, Ching-Ying; Jou, Yu-Jen; Yang, Tsuey-Ching; Huang, Su-Hua; Wan, Lei; Lin, Ying-Ju; Lin, Cheng-Wen

    2016-01-01

    SARS coronavirus (SARS-CoV) papain-like protease (PLpro) has been identified in TGF-β1 up-regulation in human promonocytes (Proteomics 2012, 12: 3193-205). This study investigates the mechanisms of SARS-CoV PLpro-induced TGF-β1 promoter activation in human lung epithelial cells and mouse models. SARS-CoV PLpro dose- and time-dependently up-regulates TGF-β1 and vimentin in A549 cells. Dual luciferase reporter assays with TGF-β1 promoter plasmids indicated that TGF-β1 promoter region between -175 to -60, the Egr-1 binding site, was responsible for TGF-β1 promoter activation induced by SARS-CoV PLpro. Subcellular localization analysis of transcription factors showed PLpro triggering nuclear translocation of Egr-1, but not NF-κB and Sp-1. Meanwhile, Egr-1 silencing by siRNA significantly reduced PLpro-induced up-regulation of TGF-β1, TSP-1 and pro-fibrotic genes. Furthermore, the inhibitors for ROS (YCG063), p38 MAPK (SB203580), and STAT3 (Stattic) revealed ROS/p38 MAPK/STAT3 pathway involving in Egr-1 dependent activation of TGF-β1 promoter induced by PLpro. In a mouse model with a direct pulmonary injection, PLpro stimulated macrophage infiltration into lung, up-regulating Egr-1, TSP-1, TGF-β1 and vimentin expression in lung tissues. The results revealed that SARS-CoV PLpro significantly triggered Egr-1 dependent activation of TGF-β1 promoter via ROS/p38 MAPK/STAT3 pathway, correlating with up-regulation of pro-fibrotic responses in vitro and in vivo. PMID:27173006

  6. SARS coronavirus papain-like protease induces Egr-1-dependent up-regulation of TGF-β1 via ROS/p38 MAPK/STAT3 pathway

    PubMed Central

    Li, Shih-Wein; Wang, Ching-Ying; Jou, Yu-Jen; Yang, Tsuey-Ching; Huang, Su-Hua; Wan, Lei; Lin, Ying-Ju; Lin, Cheng-Wen

    2016-01-01

    SARS coronavirus (SARS-CoV) papain-like protease (PLpro) has been identified in TGF-β1 up-regulation in human promonocytes (Proteomics 2012, 12: 3193-205). This study investigates the mechanisms of SARS-CoV PLpro-induced TGF-β1 promoter activation in human lung epithelial cells and mouse models. SARS-CoV PLpro dose- and time-dependently up-regulates TGF-β1 and vimentin in A549 cells. Dual luciferase reporter assays with TGF-β1 promoter plasmids indicated that TGF-β1 promoter region between −175 to −60, the Egr-1 binding site, was responsible for TGF-β1 promoter activation induced by SARS-CoV PLpro. Subcellular localization analysis of transcription factors showed PLpro triggering nuclear translocation of Egr-1, but not NF-κB and Sp-1. Meanwhile, Egr-1 silencing by siRNA significantly reduced PLpro-induced up-regulation of TGF-β1, TSP-1 and pro-fibrotic genes. Furthermore, the inhibitors for ROS (YCG063), p38 MAPK (SB203580), and STAT3 (Stattic) revealed ROS/p38 MAPK/STAT3 pathway involving in Egr-1 dependent activation of TGF-β1 promoter induced by PLpro. In a mouse model with a direct pulmonary injection, PLpro stimulated macrophage infiltration into lung, up-regulating Egr-1, TSP-1, TGF-β1 and vimentin expression in lung tissues. The results revealed that SARS-CoV PLpro significantly triggered Egr-1 dependent activation of TGF-β1 promoter via ROS/p38 MAPK/STAT3 pathway, correlating with up-regulation of pro-fibrotic responses in vitro and in vivo. PMID:27173006

  7. Piperlongumine inhibits migration of glioblastoma cells via activation of ROS-dependent p38 and JNK signaling pathways.

    PubMed

    Liu, Qian Rong; Liu, Ju Mei; Chen, Yong; Xie, Xiao Qiang; Xiong, Xin Xin; Qiu, Xin Yao; Pan, Feng; Liu, Di; Yu, Shang Bin; Chen, Xiao Qian

    2014-01-01

    Piperlongumine (PL) is recently found to kill cancer cells selectively and effectively via targeting reactive oxygen species (ROS) responses. To further explore the therapeutic effects of PL in cancers, we investigated the role and mechanisms of PL in cancer cell migration. PL effectively inhibited the migration of human glioma (LN229 or U87 MG) cells but not normal astrocytes in the scratch-wound culture model. PL did not alter EdU(+)-cells and cdc2, cdc25c, or cyclin D1 expression in our model. PL increased ROS (measured by DCFH-DA), reduced glutathione, activated p38 and JNK, increased IκBα, and suppressed NFκB in LN229 cells after scratching. All the biological effects of PL in scratched LN229 cells were completely abolished by the antioxidant N-acetyl-L-cysteine (NAC). Pharmacological administration of specific p38 (SB203580) or JNK (SP600125) inhibitors significantly reduced the inhibitory effects of PL on LN229 cell migration and NF κ B activity in scratch-wound and/or transwell models. PL prevented the deformation of migrated LN229 cells while NAC, SB203580, or SP600125 reversed PL-induced morphological changes of migrated cells. These results suggest potential therapeutic effects of PL in the treatment and prevention of highly malignant tumors such as glioblastoma multiforme (GBM) in the brain by suppressing tumor invasion and metastasis. PMID:24967005

  8. The Effects of Xiangqing Anodyne Spray on Treating Acute Soft-Tissue Injury Mainly Depend on Suppressing Activations of AKT and p38 Pathways

    PubMed Central

    Wang, Shudong; Li, Tao; Qu, Wei; Li, Xin; Ma, Shaoxin; Wang, Zheng; Liu, Wenya; Hou, Shanshan; Fu, Jihua

    2016-01-01

    Objectives. In the present study we try to elucidate the mechanism of Xiangqing anodyne spray (XQAS) effects on acute soft-tissue injury (STI). Methods. Acute STI model was established by hammer blow in the rat hind leg muscle. Within 8 hours, instantly after modeling and per 2-hour interval repeated topical applications with or without XQAS, CP or IH ethanol extracts spray (CPS and IHS) were performed, respectively; muscle swelling rate and inflammation-related biochemical parameters, muscle histological observation, and mRNA and protein expression were then examined. Results. XQAS dose-dependently suppressed STI-caused muscle swelling, proinflammatory mediator productions, and oxidative stress as well as severe pathological changes in the injured muscle tissue. Moreover, CPS mainly by blocking p38 activation while IHS majorly by blocking AKT activation led to cytoplastic IκBα degradation with NF-κB p65 translocated into the nucleus. There are synergistic effects between CP and IH components in the XQAS on preventing from acute STI with suppressing IκBα degradation, NF-κB p65 translocation, and subsequent inflammation and oxidative stress-related abnormality. Conclusion. Marked effects of XQAS on treating acute STI are ascribed to strong anti-inflammatory and antioxidative actions with a reasonable combination of CP active components, blocking p38-NF-κB pathway activated, and IH active components, blocking AKT-NF-κB pathway activated. PMID:27190541

  9. Adiponectin promotes VEGF-C-dependent lymphangiogenesis by inhibiting miR-27b through a CaMKII/AMPK/p38 signaling pathway in human chondrosarcoma cells.

    PubMed

    Huang, Chun-Yin; Chang, An-Chen; Chen, Hsien-Te; Wang, Shih-Wei; Lo, Yuan-Shun; Tang, Chih-Hsin

    2016-09-01

    Chondrosarcoma is the second most frequently occurring type of bone malignancy characterized by distant metastatic propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumour lymphangiogenesis and lymphatic metastasis. Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes. In recent years, adiponectin has also been indicated as facilitating tumorigenesis, angiogenesis and metastasis. However, the effect of adiponectin on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has remained largely a mystery. In the present study, we have shown a clinical correlation between adiponectin and VEGF-C, as well as tumour stage, in human chondrosarcoma tissues. We further demonstrated that adiponectin promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium from adiponectin-treated cells significantly induced tube formation and migration of human lymphatic endothelial cells. In addition, adiponectin knock down inhibited lymphangiogenesis in vitro and in vivo We also found that adiponectin-induced VEGF-C is mediated by the calmodulin-dependent protein kinase II (CaMKII), AMP-activated protein kinase (AMPK) and p38 signaling pathway. Furthermore, the expression of miR-27b was negatively regulated by adiponectin via the CaMKII, AMPK and p38 cascade. The present study is the first to describe the mechanism of adiponectin-promoted lymphangiogenesis by up-regulating VEGF-C expression in chondrosarcomas. Thus, adiponectin could serve as a therapeutic target in chondrosarcoma metastasis and lymphangiogenesis. PMID:27252405

  10. Hepatitis B Virus Middle Protein Enhances IL-6 Production via p38 MAPK/NF-κB Pathways in an ER Stress-Dependent Manner

    PubMed Central

    Li, Yang-Xia; Ren, Yan-Li; Fu, Hai-Jing; Zou, Ling; Yang, Ying; Chen, Zhi

    2016-01-01

    During hepatitis B virus (HBV) infection, three viral envelope proteins of HBV are overexpressed in the endoplasmic reticulum (ER). The large S protein (LHBs) and truncated middle S protein (MHBst) have been documented to play roles in regulating host gene expression and contribute to hepatic disease development. As a predominant protein at the ultrastructural level in biopsy samples taken from viremic patients, the role of the middle S protein (MHBs) remains to be understood despite its high immunogenicity. When we transfected hepatocytes with an enhanced green fluorescent protein (EGFP)-tagged MHBs expressing plasmid, the results showed that expression of MHBs cause an upregulation of IL-6 at the message RNA and protein levels through activating the p38 mitogen-activated protein kinase (p38 MAPK) and nuclear factor-kappa B (NF-κB) pathways. The use of specific inhibitors of the signaling pathways can diminish this upregulation. The use of BAPTA-AM attenuated the stimulation caused by MHBs. We further found that MHBs accumulated in the endoplasmic reticulum and increased the amount of glucose regulated protein 78 (GRP78/BiP). Our results provide a possibility that MHBs could be involved in liver disease progression. PMID:27434097

  11. Protective Effects of UCF-101 on Cerebral Ischemia-Reperfusion (CIR) is Depended on the MAPK/p38/ERK Signaling Pathway.

    PubMed

    Su, Danying; Ma, Jing; Zhang, Zhuobo; Tian, Ye; Shen, Baozhong

    2016-08-01

    This study was aimed to investigate the treatment mechanisms of 5-[5-(2-nitrophenyl) furfuryliodine]-1,3-diphenyl-2-thiobarbituric acid (UCF-101) in cerebral ischemia-reperfusion (CIR) model rats. Total of 54 healthy male Wistar rats were randomly assigned into three groups, namely sham group, vehicle group, and UCF-101 group. The CIR-injured model was established by right middle cerebral artery occlusion and reperfusion. Neurological function was assessed by an investigator according to the Longa neurologic deficit scores. Meanwhile, the cerebral tissue morphology and apoptotic neurons were evaluated by H&E and TUNEL staining, respectively. Additionally, the expressions of caspase 3, p-p38, and p-ERK were detected by immunohistochemistry or/and Western blotting assays. As results, neurologic deficit and pathological damage were obviously enhanced and TUNEL positive neurons were significantly increased in CIR-injured rats, as compared with those in sham group. Furthermore, the expressions of caspase 3, p-p38, and p-ERK were also significantly increased in vehicle group than those in sham group (P < 0.05). However, UCF-101 treatment could markedly weaken the neurologic deficit with lower scores and improve pathological condition. After UCF-101 treatment, TUNEL positive neurons as well as the expression of caspase 3 were significantly decreased than those in vehicle group (P < 0.05). Besides, p-p38 was decreased while p-ERK was increased in UCF-101 group than those in vehicle group (P < 0.05). Therefore, we concluded that the protective effects of UCF-101 might be associated with apoptosis process and MAPK signaling pathway in the CIR-injured model. PMID:26429193

  12. Focus on the p38 MAPK signaling pathway in bone development and maintenance

    PubMed Central

    Thouverey, Cyril; Caverzasio, Joseph

    2015-01-01

    The p38 mitogen-activated protein kinase (MAPK) signaling pathway can be activated in response to a wide range of extracellular signals. As a consequence, it can generate many different biological effects that depend on the stimulus and on the activated cell type. Therefore, this pathway has been found to regulate many aspects of tissue development and homeostasis. Recent work with the aid of genetically modified mice has highlighted the physiological functions of this pathway in skeletogenesis and postnatal bone maintenance. In this review, emphasis is given to the roles of the p38 MAPK pathway in chondrocyte, osteoblast and osteoclast biology. In particular, we describe the molecular mechanisms of p38 MAPK activation and downstream targets. The requirement of this pathway in physiological bone development and homeostasis is demonstrated by the ability of p38 MAPK to regulate master transcription factors controlling geneses and functions of chondrocytes, osteoblasts and osteoclasts. PMID:26131361

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

    Dai, Hai-Long; Hu, Wei-Yuan; Jiang, Li-Hong; Li, Le; Gaung, Xue-Feng; Xiao, Zhi-Cheng

    2016-01-01

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

  15. Excess salt exacerbates blood-brain barrier disruption via a p38/MAPK/SGK1-dependent pathway in permanent cerebral ischemia

    PubMed Central

    Zhang, Tongshuai; Fang, Shaohong; Wan, Cong; Kong, Qingfei; Wang, Guangyou; Wang, Shuangshuang; Zhang, Haoqiang; Zou, Haifeng; Sun, Bo; Sun, Wei; Zhang, Yao; Mu, Lili; Wang, Jinghua; Wang, Jing; Zhang, Haiyu; Wang, Dandan; Li, Hulun

    2015-01-01

    High salt diet (HSD) is one of the most important risk factors that contribute to many vascular diseases including ischemic stroke. One proposed mechanism underlying the disruption of blood-brain barrier (BBB) mediated by HSD is indirectly through enhancing blood pressure. The direct role of HSD on BBB integrity is unclear. Our purpose is to determine whether and how HSD might be involved in BBB breakdown during ischemia. To test that, we induced model of cerebral ischemia by permanent middle cerebral artery ligation (pMCAL) in either normal diet or HSD fed mice. We observed that HSD significantly enhanced ischemic brain damage which was associated with enhanced BBB disruption, increased leukocytes infiltration and loss of tight junction (TJ) proteins expression without apparently altering blood pressure. Our in vitro experiment also revealed that sodium chloride (NaCl) treatment down-regulated TJ protein expression by endothelial cells and substantially increased BBB permeability during starvation. Inhibition of p38/MAPK/SGK1 pathway eliminated the effect of NaCl on BBB permeability in vitro. In addition, we noticed a positive correlation between urinary sodium levels and ischemic lesion size in stroke patients. Together, our study demonstrates a hypertension-independent role of HSD during ischemia and provides rationale for post cerebral ischemic attack management. PMID:26549644

  16. The p38 MAPK and JNK pathways protect host cells against Clostridium perfringens beta-toxin.

    PubMed

    Nagahama, Masahiro; Shibutani, Masahiro; Seike, Soshi; Yonezaki, Mami; Takagishi, Teruhisa; Oda, Masataka; Kobayashi, Keiko; Sakurai, Jun

    2013-10-01

    Clostridium perfringens beta-toxin is an important agent of necrotic enteritis and enterotoxemia. Beta-toxin is a pore-forming toxin (PFT) that causes cytotoxicity. Two mitogen-activated protein kinase (MAPK) pathways (p38 and c-Jun N-terminal kinase [JNK]-like) provide cellular defense against various stresses. To investigate the role of the MAPK pathways in the toxic effect of beta-toxin, we examined cytotoxicity in five cell lines. Beta-toxin induced cytotoxicity in cells in the following order: THP-1 = U937 > HL-60 > BALL-1 = MOLT-4. In THP-1 cells, beta-toxin formed oligomers on lipid rafts in membranes and induced the efflux of K(+) from THP-1 cells in a dose- and time-dependent manner. The phosphorylation of p38 MAPK and JNK occurred in response to an attack by beta-toxin. p38 MAPK (SB203580) and JNK (SP600125) inhibitors enhanced toxin-induced cell death. Incubation in K(+)-free medium intensified p38 MAPK activation and cell death induced by the toxin, while incubation in K(+)-high medium prevented those effects. While streptolysin O (SLO) reportedly activates p38 MAPK via reactive oxygen species (ROS), we showed that this pathway did not play a major role in p38 phosphorylation in beta-toxin-treated cells. Therefore, we propose that beta-toxin induces activation of the MAPK pathway to promote host cell survival. PMID:23876806

  17. The p38 MAPK and JNK Pathways Protect Host Cells against Clostridium perfringens Beta-Toxin

    PubMed Central

    Shibutani, Masahiro; Seike, Soshi; Yonezaki, Mami; Takagishi, Teruhisa; Oda, Masataka; Kobayashi, Keiko; Sakurai, Jun

    2013-01-01

    Clostridium perfringens beta-toxin is an important agent of necrotic enteritis and enterotoxemia. Beta-toxin is a pore-forming toxin (PFT) that causes cytotoxicity. Two mitogen-activated protein kinase (MAPK) pathways (p38 and c-Jun N-terminal kinase [JNK]-like) provide cellular defense against various stresses. To investigate the role of the MAPK pathways in the toxic effect of beta-toxin, we examined cytotoxicity in five cell lines. Beta-toxin induced cytotoxicity in cells in the following order: THP-1 = U937 > HL-60 > BALL-1 = MOLT-4. In THP-1 cells, beta-toxin formed oligomers on lipid rafts in membranes and induced the efflux of K+ from THP-1 cells in a dose- and time-dependent manner. The phosphorylation of p38 MAPK and JNK occurred in response to an attack by beta-toxin. p38 MAPK (SB203580) and JNK (SP600125) inhibitors enhanced toxin-induced cell death. Incubation in K+-free medium intensified p38 MAPK activation and cell death induced by the toxin, while incubation in K+-high medium prevented those effects. While streptolysin O (SLO) reportedly activates p38 MAPK via reactive oxygen species (ROS), we showed that this pathway did not play a major role in p38 phosphorylation in beta-toxin-treated cells. Therefore, we propose that beta-toxin induces activation of the MAPK pathway to promote host cell survival. PMID:23876806

  18. Basic Properties of the p38 Signaling Pathway in Response to Hyperosmotic Shock

    PubMed Central

    Ben Messaoud, Nabil; Katzarova, Ilina; López, José M.

    2015-01-01

    Some properties of signaling systems, like ultrasensitivity, hysteresis (a form of biochemical memory), and all-or-none responses at a single cell level, are important to understand the regulation of irreversible processes. Xenopus oocytes are a suitable cell model to study these properties. The p38 MAPK (mitogen-activated protein kinase) pathway is activated by different stress stimuli, including osmostress, and regulates multiple biological processes, from immune response to cell cycle. Recently, we have reported that activation of p38 and JNK regulate osmostress-induced apoptosis in Xenopus oocytes and that sustained activation of p38 accelerates cytochrome c release and caspase-3 activation. However, the signaling properties of p38 in response to hyperosmotic shock have not been studied. Here we show, using Xenopus oocytes as a cell model, that hyperosmotic shock activates the p38 signaling pathway with an ultrasensitive and bimodal response in a time-dependent manner, and with low hysteresis. At a single cell level, p38 activation is not well correlated with cytochrome c release 2 h after hyperosmotic shock, but a good correlation is observed at 4 h after treatment. Interestingly, cytochrome c microinjection induces p38 phosphorylation through caspase-3 activation, and caspase inhibition reduces p38 activation induced by osmostress, indicating that a positive feedback loop is engaged by hyperosmotic shock. To know the properties of the stress protein kinases activated by hyperosmotic shock will facilitate the design of computational models to predict cellular responses in human diseases caused by perturbations in fluid osmolarity. PMID:26335493

  19. Afzelin positively regulates melanogenesis through the p38 MAPK pathway.

    PubMed

    Jung, Eunsun; Kim, Jin Hee; Kim, Mi Ok; Jang, Sunghee; Kang, Mingyeong; Oh, Sae Woong; Nho, Youn Hwa; Kang, Seung Hyun; Kim, Min Hee; Park, See-Hyoung; Lee, Jongsung

    2016-07-25

    Melanogenesis refers to synthesis of the skin pigment melanin, which plays a critical role in the protection of skin against ultraviolet irradiation and oxidative stressors. We investigated the effects of afzelin on melanogenesis and its mechanisms of action in human epidermal melanocytes. In this study, we found that afzelin increased both melanin content and tyrosinase activity in a concentration-dependent manner. While the mRNA levels of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein (TRP)-1 increased following afzelin treatment, the mRNA levels of TRP-2 were not affected by afzelin. Likewise, afzelin increased the protein levels of MITF, TRP-1, and tyrosinase but not TRP-2. Mechanistically, we found that afzelin regulated melanogenesis by upregulating MITF through phosphorylation of p38 mitogen-activated protein kinase (MAPK), independent of cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling. Taken together, these findings indicate that the promotion of melanogenesis by afzelin occurs through increased MITF gene expression, which is mediated by activation of p38 MAPK, and suggest that afzelin may be useful as a protective agent against ultraviolet irradiation. PMID:27287415

  20. Unfolded protein response induced by Brefeldin A increases collagen type I levels in hepatic stellate cells through an IRE1α, p38 MAPK and Smad-dependent pathway.

    PubMed

    de Galarreta, Marina Ruiz; Navarro, Amaia; Ansorena, Eduardo; Garzón, Antonia García; Mòdol, Teresa; López-Zabalza, María J; Martínez-Irujo, Juan J; Iraburu, María J

    2016-08-01

    Unfolded protein response (UPR) triggered as a consequence of ER stress has been shown to be involved in the development of different pathologies, including fibrotic disorders. In the present paper we explore the role played by UPR on a key fibrogenic parameter in the liver: collagen type I levels in activated hepatic stellate cells (HSC). Using Brefeldin A (BFA) as an ER stress inducer we found that UPR correlated with enhanced mRNA and protein levels of collagen type I in a cell line of immortalized non-tumoral rat HSC. Analysis of the three branches of UPR revealed the activation of IRE1α, PERK and ATF6 in response to BFA, although PERK activation was shown not to be involved in the fibrogenic action of BFA. BFA also activated p38 MAPK in an IRE1α-dependent way and the p38 MAPK inhibitor SB203580 prevented the increase in collagen type I mRNA and protein levels caused by BFA, suggesting the involvement of this kinase on this effect. Analysis of Smad activation showed that phosphorylated nuclear levels of Smad2 and 3 were increased in response to BFA treatment. Inhibition of Smad3 phosphorylation by SIS3 prevented the enhancement of collagen type I levels caused by BFA. Pretreatment with IRE1α and p38 MAPK inhibitors also prevented the increased p-Smad3 accumulation in the nucleus, suggesting an IRE1α-p38 MAPK-Smad pathway to be responsible for the fibrogenic action of BFA on HSC. PMID:27155082

  1. Acetaminophen induces JNK/p38 signaling and activates the caspase-9-3-dependent cell death pathway in human mesenchymal stem cells

    PubMed Central

    YIANG, GIOU-TENG; YU, YUNG-LUNG; LIN, KO-TING; CHEN, JEN-NI; CHANG, WEI-JUNG; WEI, CHYOU-WEI

    2015-01-01

    Acetaminophen (APAP) is a widely used analgesic and antipyretic drug. Generally, the therapeutic dose of APAP is clinically safe, however, high doses of APAP can cause acute liver and kidney injury. Therefore, the majority of previous studies have focussed on elucidating the mechanisms of APAP-induced hepatotoxicity and nephrotoxicity, in addition to examining ways to treat these conditions in clinical cases. However, few studies have reported APAP-induced intoxication in human stem cells. Stem cells are important in cell proliferation, differentiation and repair during human development, particularly during fetal and child development. At present, whether APAP causes cytotoxic effects in human stem cells remains to be elucidated, therefore, the present study aimed to investigate the cellular effects of APAP treatment in human stem cells. The results of the present study revealed that high-dose APAP induced more marked cytotoxic effects in human mesenchymal stem cells (hMSCs) than in renal tubular cells. In addition, increased levels of hydrogen peroxide (H2O2), phosphorylation of c-Jun N-terminal kinase and p38, and activation of caspase-9/-3 cascade were observed in the APAP-treated hMSCs. By contrast, antioxidants, including vitamin C reduced APAP-induced augmentations in H2O2 levels, but did not inhibit the APAP-induced cytotoxic effects in the hMSCs. These results suggested that high doses of APAP may cause serious damage towards hMSCs. PMID:26096646

  2. Innate immune responses to rotavirus infection in macrophages depend on MAVS but involve neither the NLRP3 inflammasome nor JNK and p38 signaling pathways.

    PubMed

    Di Fiore, Izabel J M; Holloway, Gavan; Coulson, Barbara S

    2015-10-01

    Rotavirus infection is a major cause of life-threatening infantile gastroenteritis. The innate immune system provides an immediate mechanism of suppressing viral replication and is necessary for an effective adaptive immune response. Innate immunity involves host recognition of viral infection and establishment of a powerful antiviral state through the expression of pro-inflammatory cytokines such as type-1 interferon (IFN). Macrophages, the front-line cells of innate immunity, produce IFN and other cytokines in response to viral infection. However, the role of macrophages during rotavirus infection is not well defined. We demonstrate here that RRV rotavirus triggers the production of proinflammatory cytokines from mouse bone marrow-derived macrophages. IFN and antiviral cytokine production was abolished in rotavirus-infected MAVS (-/-) macrophages. This indicates that rotavirus triggers innate immunity in macrophages through RIG-I and/or MDA5 viral recognition, and MAVS signaling is essential for cytokine responses in macrophages. Rotavirus induced IFN expression in both wild type and MDA5 (-/-) macrophages, showing that MDA5 is not essential for IFN secretion following infection, and RIG-I and MDA5 may act redundantly in promoting rotavirus recognition. Interestingly, rotavirus neither stimulated mitogen-activated protein kinases p38 and JNK nor activated the NLRP3 inflammasome, demonstrating that these components might not be involved in innate responses to rotavirus infection in macrophages. Our results indicate that rotavirus elicits intracellular signaling in macrophages, resulting in the induction of IFN and antiviral cytokines, and advance our understanding of the involvement of these cells in innate responses against rotavirus. PMID:26079065

  3. Role of Rho/ROCK and p38 MAP kinase pathways in transforming growth factor-beta-mediated Smad-dependent growth inhibition of human breast carcinoma cells in vivo.

    PubMed

    Kamaraju, Anil K; Roberts, Anita B

    2005-01-14

    TGF-beta is a multifunctional cytokine known to exert its biological effects through a variety of signaling pathways of which Smad signaling is considered to be the main mediator. At present, the Smad-independent pathways, their interactions with each other, and their roles in TGF-beta-mediated growth inhibitory effects are not well understood. To address these questions, we have utilized a human breast cancer cell line MCF10CA1h and demonstrate that p38 MAP kinase and Rho/ROCK pathways together with Smad2 and Smad3 are necessary for TGF-beta-mediated growth inhibition of this cell line. We show that Smad2/3 are indispensable for TGF-beta-mediated growth inhibition, and that both p38 and Rho/ROCK pathways affect the linker region phosphorylation of Smad2/3. Further, by using Smad3 mutated at the putative phosphorylation sites in the linker region, we demonstrate that phosphorylation at Ser203 and Ser207 residues is required for the full transactivation potential of Smad3, and that these residues are targets of the p38 and Rho/ROCK pathways. We demonstrate that activation of the p38 MAP kinase pathway is necessary for the full transcriptional activation potential of Smad2/Smad3 by TGF-beta, whereas activity of Rho/ROCK is necessary for both down-regulation of c-Myc protein and up-regulation of p21waf1 protein, directly interfering with p21waf1 transcription. Our results not only implicate Rho/ROCK and p38 MAPK pathways as necessary for TGF-beta-mediated growth inhibition, but also demonstrate their individual contributions and the basis for their cooperation with each other. PMID:15520018

  4. Baicalein Reduces the Invasion of Glioma Cells via Reducing the Activity of p38 Signaling Pathway

    PubMed Central

    Lei, Xiaoming; Li, Siyuan; Zhang, Yong; Meng, Lihua; Xue, Rongliang; Li, Zongfang

    2014-01-01

    Baicalein, one of the major flavonids in Scutellaria baicalensis, has historically been used in anti-inflammatory and anti-cancer therapies. However, the anti-metastatic effect and related mechanism(s) in glioma are still unclear. In this study, we thus utilized glioma cell lines U87MG and U251MG to explore the effect of baicalein. We found that administration of baicalein significantly inhibited migration and invasion of glioma cells. In addition, after treating with baicalein for 24 h, there was a decrease in the levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression as well as proteinase activity in glioma cells. Conversely, the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 was increased in a dose-dependent manner. Moreover, baicalein treatment significantly decreased the phosphorylated level of p38, but not ERK1/2, JNK1/2 and PI3K/Akt. Combined treatment with a p38 inhibitor (SB203580) and baicalein resulted in the synergistic reduction of MMP-2 and MMP-9 expression and then increase of TIMP-1 and TIMP-2 expression; and the invasive capabilities of U87MG cells were also inhibited. However, p38 chemical activator (anisomycin) could block these effects produced by baicalein, suggesting baicalein directly downregulate the p38 signaling pathway. In conclusion, baicalein inhibits glioma cells invasion and metastasis by reducing cell motility and migration via suppression of p38 signaling pathway, suggesting that baicalein is a potential therapeutic agent for glioma. PMID:24587321

  5. The p38 MAP kinase pathway modulates the hypoxia response and glutamate receptor trafficking in aging neurons

    PubMed Central

    Park, Eun Chan; Rongo, Christopher

    2016-01-01

    Neurons are sensitive to low oxygen (hypoxia) and employ a conserved pathway to combat its effects. Here, we show that p38 MAP Kinase (MAPK) modulates this hypoxia response pathway in C. elegans. Mutants lacking p38 MAPK components pmk-1 or sek-1 resemble mutants lacking the hypoxia response component and prolyl hydroxylase egl-9, with impaired subcellular localization of Mint orthologue LIN-10, internalization of glutamate receptor GLR-1, and depression of GLR-1-mediated behaviors. Loss of p38 MAPK impairs EGL-9 protein localization in neurons and activates the hypoxia-inducible transcription factor HIF-1, suggesting that p38 MAPK inhibits the hypoxia response pathway through EGL-9. As animals age, p38 MAPK levels decrease, resulting in GLR-1 internalization; this age-dependent downregulation can be prevented through either p38 MAPK overexpression or removal of CDK-5, an antagonizing kinase. Our findings demonstrate that p38 MAPK inhibits the hypoxia response pathway and determines how aging neurons respond to hypoxia through a novel mechanism. DOI: http://dx.doi.org/10.7554/eLife.12010.001 PMID:26731517

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

    PubMed Central

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

    2015-01-01

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

  7. Fas activation of the p38 mitogen-activated protein kinase signalling pathway requires ICE/CED-3 family proteases.

    PubMed Central

    Juo, P; Kuo, C J; Reynolds, S E; Konz, R F; Raingeaud, J; Davis, R J; Biemann, H P; Blenis, J

    1997-01-01

    The Fas receptor mediates a signalling cascade resulting in programmed cell death (apoptosis) within hours of receptor cross-linking. In this study Fas activated the stress-responsive mitogen-activated protein kinases, p38 and JNK, within 2 h in Jurkat T lymphocytes but not the mitogen-responsive kinase ERK1 or pp70S6k. Fas activation of p38 correlated temporally with the onset of apoptosis, and transfection of constitutively active MKK3 (glu), an upstream regulator of p38, potentiated Fas-induced cell death, suggesting a potential involvement of the MKK3/p38 activation pathway in Fas-mediated apoptosis. Fas has been shown to require ICE (interleukin-1 beta-converting enzyme) family proteases to induce apoptosis from studies utilizing the cowpox ICE inhibitor protein CrmA, the synthetic tetrapeptide ICE inhibitor YVAD-CMK, and the tripeptide pan-ICE inhibitor Z-VAD-FMK. In this study, crmA antagonized, and YVAD-CMK and Z-VAD-FMK completely inhibited, Fas activation of p38 kinase activity, demonstrating that Fas-dependent activation of p38 requires ICE/CED-3 family members and conversely that the MKK3/p38 activation cascade represents a downstream target for the ICE/CED-3 family proteases. Intriguingly, p38 activation by sorbitol and etoposide was resistant to YVAD-CMK and Z-VAD-FMK, suggesting the existence of an additional mechanism(s) of p38 regulation. The ICE/CED-3 family-p38 regulatory relationship described in the current work indicates that in addition to the previously described destructive cleavage of substrates such as poly(ADP ribose) polymerase, lamins, and topoisomerase, the apoptotic cysteine proteases also function to regulate stress kinase signalling cascades. PMID:8972182

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

    PubMed

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

    2016-09-01

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

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

    SciTech Connect

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

    2010-04-16

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

  10. Involvement of p38 MAPK in haemozoin-dependent MMP-9 enhancement in human monocytes.

    PubMed

    Khadjavi, Amina; Valente, Elena; Giribaldi, Giuliana; Prato, Mauro

    2014-01-01

    The lipid moiety of natural haemozoin (nHZ, malarial pigment) was previously shown to enhance expression and release of human monocyte matrix metalloproteinase-9 (MMP-9), and a major role for 15-(S,R)-hydroxy-6,8,11,13-eicosatetraenoic acid (15-HETE), a nHZ lipoperoxidation product, was proposed. Here, the underlying mechanisms were investigated, focusing on the involvement of mitogen-activated protein kinases (MAPKs). Results showed that nHZ promoted either early or late p38 MAPK phosphorylation; however, nHZ did not modify basal phosphorylation/expression ratios of extracellular signal-regulated kinase-1/2 and c-jun N-terminal kinase-1/2. 15-HETE mimicked nHZ effects on p38 MAPK, whereas lipid-free synthetic (s)HZ and delipidized (d)HZ did not. Consistently, both nHZ and 15-HETE also promoted phosphorylation of MAPK-activated protein kinase-2, a known p38 MAPK substrate; such an effect was abolished by SB203580, a synthetic p38 MAPK inhibitor. SB203580 also abrogated nHZ-dependent and 15-HETE-dependent enhancement of MMP-9 mRNA and protein (latent and activated forms) levels in cell lysates and supernatants. Collectively, these data suggest that in human monocytes, nHZ and 15-HETE upregulate MMP-9 expression and secretion through activation of p38 MAPK pathway. The present work provides new evidence on mechanisms underlying MMP-9 deregulation in malaria, which might be helpful to design new specific drugs for adjuvant therapy in complicated malaria. PMID:23468369

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

    PubMed Central

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

    2016-01-01

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

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

    SciTech Connect

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

    2014-07-18

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

  13. Serotonin type-1D receptor stimulation of A-type K(+) channel decreases membrane excitability through the protein kinase A- and B-Raf-dependent p38 MAPK pathways in mouse trigeminal ganglion neurons.

    PubMed

    Zhao, Xianyang; Zhang, Yuan; Qin, Wenjuan; Cao, Junping; Zhang, Yi; Ni, Jianqiang; Sun, Yangang; Jiang, Xinghong; Tao, Jin

    2016-08-01

    Although recent studies have implicated serotonin 5-HT1B/D receptors in the nociceptive sensitivity of primary afferent neurons, the underlying molecular and cellular mechanisms remain unclear. In this study, we identified a novel functional role of the 5-HT1D receptor subtype in regulating A-type potassium (K(+)) currents (IA) as well as membrane excitability in small trigeminal ganglion (TG) neurons. We found that the selective activation of 5-HT1D, rather than 5-HT1B, receptors reversibly increased IA, while the sustained delayed rectifier K(+) current was unaffected. The 5-HT1D-mediated IA increase was associated with a depolarizing shift in the voltage dependence of inactivation. Blocking G-protein signaling with pertussis toxin or by intracellular application of a selective antibody raised against Gαo or Gβ abolished the 5-HT1D effect on IA. Inhibition of protein kinase A (PKA), but not of phosphatidylinositol 3-kinase or protein kinase C, abolished the 5-HT1D-mediated IA increase. Analysis of phospho-p38 (p-p38) revealed that activation of 5-HT1D, but not 5-HT1B, receptors significantly activated p38, while p-ERK and p-JNK were unaffected. The p38 MAPK inhibitor SB203580, but not its inactive analogue SB202474, and inhibition of B-Raf blocked the 5-HT1D-mediated IA response. Functionally, we observed a significantly decreased action potential firing rate induced by the 5-HT1D receptors; pretreatment with 4-aminopyridine abolished this effect. Taken together, these results suggest that the activation of 5-HT1D receptors selectively enhanced IA via the Gβγ of the Go-protein, PKA, and the sequential B-Raf-dependent p38 MAPK signaling cascade. This 5-HT1D receptor effect may contribute to neuronal hypoexcitability in small TG neurons. PMID:27156838

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

    PubMed Central

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

    2016-01-01

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

  15. A role for p38(MAPK)/HSP27 pathway in smooth muscle cell migration.

    PubMed

    Hedges, J C; Dechert, M A; Yamboliev, I A; Martin, J L; Hickey, E; Weber, L A; Gerthoffer, W T

    1999-08-20

    Smooth muscle cells are exposed to growth factors and cytokines that contribute to pathological states including airway hyperresponsiveness, atherosclerosis, angiogenesis, smooth muscle hypertrophy, and hyperplasia. A common feature of several of these conditions is migration of smooth muscle beyond the initial boundary of the organ. Signal transduction pathways activated by extracellular signals that instigate migration are mostly undefined in smooth muscles. We measured migration of cultured tracheal myocytes in response to platelet-derived growth factor, interleukin-1beta, and transforming growth factor-beta. Cellular migration was blocked by SB203580, an inhibitor of p38(MAPK). Time course experiments demonstrated increased phosphorylation of p38(MAPK). Activation of p38(MAPK) resulted in the phosphorylation of HSP27 (heat shock protein 27), which may modulate F-actin polymerization. Inhibition of p38(MAPK) activity inhibited phosphorylation of HSP27. Adenovirus-mediated expression of activated mutant MAPK kinase 6b(E), an upstream activator for p38(MAPK), increased cell migration, whereas overexpression of p38alpha MAPK dominant negative mutant and an HSP27 phosphorylation mutant blocked cell migration completely. The results indicate that activation of the p38(MAPK) pathway by growth factors and proinflammatory cytokines regulates smooth muscle cell migration and may contribute to pathological states involving smooth muscle dysfunction. PMID:10446196

  16. JNK and p38 mitogen-activated protein kinase pathways contribute to porcine epidemic diarrhea virus infection.

    PubMed

    Lee, Changhee; Kim, Youngnam; Jeon, Ji Hyun

    2016-08-15

    The mitogen-activated protein kinase (MAPK) pathways, which are central building blocks in the intracellular signaling network, are often manipulated by viruses of diverse families to favor their replication. Among the MAPK family, the extracellular signal-regulated kinase (ERK) pathway is known to be modulated during the infection with porcine epidemic diarrhea virus (PEDV); however, involvement of stress-activated protein kinases (SAPKs) comprising p38 MAPK and c-Jun NH2-terminal kinase (JNK) remains to be determined. Therefore, in the present study, we investigated whether activation of p38 MAPK and JNK cascades is required for PEDV replication. Our results showed that PEDV activates p38 MAPK and JNK1/2 up to 24h post-infection, whereas, thereafter their phosphorylation levels recede to baseline levels or even fall below them. Notably, UV-irradiated inactivated PEDV, which can enter cells but cannot replicate inside them, failed to induce phosphorylation of p38 MAPK and JNK1/2 suggesting that viral biosynthesis is essential for activation of these kinases. Treatment of cells with selective p38 or JNK inhibitors markedly impaired PEDV replication in a dose-dependent manner and these antiviral effects were found to be maximal during the early times of the infection. Furthermore, direct pharmacological inhibition of p38 MAPK or JNK1/2 activation resulted in a significant reduction of viral RNA synthesis, viral protein expression, and progeny release. However, independent treatments with either SAPK inhibitor did not inhibit PEDV-induced apoptotic cell death mediated by activation of mitochondrial apoptosis-inducing factor (AIF) suggesting that SAPKs are irrelevant to the apoptosis pathway during PEDV infection. In summary, our data demonstrated critical roles of the p38 and JNK1/2 signaling pathways in facilitating successful viral infection during the post-entry steps of the PEDV life cycle. PMID:27215486

  17. Aberrant Activation of p38 MAP Kinase-Dependent Innate Immune Responses Is Toxic to Caenorhabditis elegans

    PubMed Central

    Cheesman, Hilary K.; Feinbaum, Rhonda L.; Thekkiniath, Jose; Dowen, Robert H.; Conery, Annie L.; Pukkila-Worley, Read

    2016-01-01

    Inappropriate activation of innate immune responses in intestinal epithelial cells underlies the pathophysiology of inflammatory disorders of the intestine. Here we examine the physiological effects of immune hyperactivation in the intestine of the nematode Caenorhabditis elegans. We previously identified an immunostimulatory xenobiotic that protects C. elegans from bacterial infection by inducing immune effector expression via the conserved p38 MAP kinase pathway, but was toxic to nematodes developing in the absence of pathogen. To investigate a possible connection between the toxicity and immunostimulatory properties of this xenobiotic, we conducted a forward genetic screen for C. elegans mutants that are resistant to the deleterious effects of the compound, and identified five toxicity suppressors. These strains contained hypomorphic mutations in each of the known components of the p38 MAP kinase cassette (tir-1, nsy-1, sek-1, and pmk-1), demonstrating that hyperstimulation of the p38 MAPK pathway is toxic to animals. To explore mechanisms of immune pathway regulation in C. elegans, we conducted another genetic screen for dominant activators of the p38 MAPK pathway, and identified a single allele that had a gain-of-function (gf) mutation in nsy-1, the MAP kinase kinase kinase that acts upstream of p38 MAPK pmk-1. The nsy-1(gf) allele caused hyperinduction of p38 MAPK PMK-1-dependent immune effectors, had greater levels of phosphorylated p38 MAPK, and was more resistant to killing by the bacterial pathogen Pseudomonas aeruginosa compared to wild-type controls. In addition, the nsy-1(gf) mutation was toxic to developing animals. Together, these data suggest that the activity of the MAPKKK NSY-1 is tightly regulated as part of a physiological mechanism to control p38 MAPK-mediated innate immune hyperactivation, and ensure cellular homeostasis in C. elegans. PMID:26818074

  18. Aberrant Activation of p38 MAP Kinase-Dependent Innate Immune Responses Is Toxic to Caenorhabditis elegans.

    PubMed

    Cheesman, Hilary K; Feinbaum, Rhonda L; Thekkiniath, Jose; Dowen, Robert H; Conery, Annie L; Pukkila-Worley, Read

    2016-03-01

    Inappropriate activation of innate immune responses in intestinal epithelial cells underlies the pathophysiology of inflammatory disorders of the intestine. Here we examine the physiological effects of immune hyperactivation in the intestine of the nematode Caenorhabditis elegans. We previously identified an immunostimulatory xenobiotic that protects C. elegans from bacterial infection by inducing immune effector expression via the conserved p38 MAP kinase pathway, but was toxic to nematodes developing in the absence of pathogen. To investigate a possible connection between the toxicity and immunostimulatory properties of this xenobiotic, we conducted a forward genetic screen for C. elegans mutants that are resistant to the deleterious effects of the compound, and identified five toxicity suppressors. These strains contained hypomorphic mutations in each of the known components of the p38 MAP kinase cassette (tir-1, nsy-1, sek-1, and pmk-1), demonstrating that hyperstimulation of the p38 MAPK pathway is toxic to animals. To explore mechanisms of immune pathway regulation in C. elegans, we conducted another genetic screen for dominant activators of the p38 MAPK pathway, and identified a single allele that had a gain-of-function (gf) mutation in nsy-1, the MAP kinase kinase kinase that acts upstream of p38 MAPK pmk-1. The nsy-1(gf) allele caused hyperinduction of p38 MAPK PMK-1-dependent immune effectors, had greater levels of phosphorylated p38 MAPK, and was more resistant to killing by the bacterial pathogen Pseudomonas aeruginosa compared to wild-type controls. In addition, the nsy-1(gf) mutation was toxic to developing animals. Together, these data suggest that the activity of the MAPKKK NSY-1 is tightly regulated as part of a physiological mechanism to control p38 MAPK-mediated innate immune hyperactivation, and ensure cellular homeostasis in C. elegans. PMID:26818074

  19. The p38 MAPK pathway is essential for skeletogenesis and bone homeostasis in mice

    PubMed Central

    Greenblatt, Matthew B.; Shim, Jae-Hyuck; Zou, Weiguo; Sitara, Despina; Schweitzer, Michelle; Hu, Dorothy; Lotinun, Sutada; Sano, Yasuyo; Baron, Roland; Park, Jin Mo; Arthur, Simon; Xie, Min; Schneider, Michael D.; Zhai, Bo; Gygi, Steven; Davis, Roger; Glimcher, Laurie H.

    2010-01-01

    Nearly every extracellular ligand that has been found to play a role in regulating bone biology acts, at least in part, through MAPK pathways. Nevertheless, much remains to be learned about the contribution of MAPKs to osteoblast biology in vivo. Here we report that the p38 MAPK pathway is required for normal skeletogenesis in mice, as mice with deletion of any of the MAPK pathway member–encoding genes MAPK kinase 3 (Mkk3), Mkk6, p38a, or p38b displayed profoundly reduced bone mass secondary to defective osteoblast differentiation. Among the MAPK kinase kinase (MAP3K) family, we identified TGF-β–activated kinase 1 (TAK1; also known as MAP3K7) as the critical activator upstream of p38 in osteoblasts. Osteoblast-specific deletion of Tak1 resulted in clavicular hypoplasia and delayed fontanelle fusion, a phenotype similar to the cleidocranial dysplasia observed in humans haploinsufficient for the transcription factor runt-related transcription factor 2 (Runx2). Mechanistic analysis revealed that the TAK1–MKK3/6–p38 MAPK axis phosphorylated Runx2, promoting its association with the coactivator CREB-binding protein (CBP), which was required to regulate osteoblast genetic programs. These findings reveal an in vivo function for p38β and establish that MAPK signaling is essential for bone formation in vivo. These results also suggest that selective p38β agonists may represent attractive therapeutic agents to prevent bone loss associated with osteoporosis and aging. PMID:20551513

  20. Osmotic stress regulates the stability of cyclin D1 in a p38SAPK2-dependent manner.

    PubMed

    Casanovas, O; Miró, F; Estanyol, J M; Itarte, E; Agell, N; Bachs, O

    2000-11-10

    We report here that different cell stresses regulate the stability of cyclin D1 protein. Exposition of Granta 519 cells to osmotic shock, oxidative stress, and arsenite induced the post-transcriptional down-regulation of cyclin D1. In the case of osmotic shock, this effect was completely reversed by the addition of p38(SAPK2)-specific inhibitors (SB203580 or SB220025), indicating that this effect is dependent on p38(SAPK2) activity. Moreover, the use of proteasome inhibitors prevented this down-regulation. Thus, osmotic shock induces proteasomal degradation of cyclin D1 protein by a p38(SAPK2)-dependent pathway. The effect of p38(SAPK2) on cyclin D1 stability might be mediated by direct phosphorylation at specific sites. We found that p38(SAPK2) phosphorylates cyclin D1 in vitro at Thr(286) and that this phosphorylation triggers the ubiquitination of cyclin D1. These results link for the first time a stress-induced MAP kinase pathway to cyclin D1 protein stability, and they will help to understand the molecular mechanisms by which stress transduction pathways regulate the cell cycle machinery and take control over cell proliferation. PMID:10952989

  1. Association with Soil Bacteria Enhances p38-Dependent Infection Resistance in Caenorhabditis elegans

    PubMed Central

    Montalvo-Katz, Sirena; Huang, Hao; Appel, Michael David; Berg, Maureen

    2013-01-01

    The importance of our inner microbial communities for proper immune responses against invading pathogens is now well accepted, but the mechanisms underlying this protection are largely unknown. In this study, we used Caenorhabditis elegans to investigate such mechanisms. Since very little is known about the microbes interacting with C. elegans in its natural environment, we began by taking the first steps to characterize the C. elegans microbiota. We established a natural-like environment in which initially germfree, wild-type larvae were grown on enriched soil. Bacterial members of the adult C. elegans microbiota were isolated by culture and identified using 16S rRNA gene sequencing. Using pure cultures of bacterial isolates as food, we identified two, Bacillus megaterium and Pseudomonas mendocina, that enhanced resistance to a subsequent infection with the Gram-negative pathogen Pseudomonas aeruginosa. Whereas protection by B. megaterium was linked to impaired egg laying, corresponding to a known trade-off between fecundity and resistance, the mechanism underlying protection conferred by P. mendocina depended on weak induction of immune genes regulated by the p38 MAPK pathway. Disruption of the p38 ortholog, pmk-1, abolished protection. P. mendocina enhanced resistance to P. aeruginosa but not to the Gram-positive pathogen Enterococcus faecalis. Furthermore, protection from P. aeruginosa was similarly induced by a P. aeruginosa gacA mutant with attenuated virulence but not by a different C. elegans-associated Pseudomonas sp. isolate. Our results support a pivotal role for the conserved p38 pathway in microbiota-initiated immune protection and suggest that similarity between microbiota members and pathogens may play a role in such protection. PMID:23230286

  2. p38α MAPK pathway: A key factor in colorectal cancer therapy and chemoresistance

    PubMed Central

    Grossi, Valentina; Peserico, Alessia; Tezil, Tugsan; Simone, Cristiano

    2014-01-01

    Colorectal cancer (CRC) remains one of the most common malignancies in the world. Although surgical resection combined with adjuvant therapy is effective at the early stages of the disease, resistance to conventional therapies is frequently observed in advanced stages, where treatments become ineffective. Resistance to cisplatin, irinotecan and 5-fluorouracil chemotherapy has been shown to involve mitogen-activated protein kinase (MAPK) signaling and recent studies identified p38α MAPK as a mediator of resistance to various agents in CRC patients. Studies published in the last decade showed a dual role for the p38α pathway in mammals. Its role as a negative regulator of proliferation has been reported in both normal (including cardiomyocytes, hepatocytes, fibroblasts, hematopoietic and lung cells) and cancer cells (colon, prostate, breast, lung tumor cells). This function is mediated by the negative regulation of cell cycle progression and the transduction of some apoptotic stimuli. However, despite its anti-proliferative and tumor suppressor activity in some tissues, the p38α pathway may also acquire an oncogenic role involving cancer related-processes such as cell metabolism, invasion, inflammation and angiogenesis. In this review, we summarize current knowledge about the predominant role of the p38α MAPK pathway in CRC development and chemoresistance. In our view, this might help establish the therapeutic potential of the targeted manipulation of this pathway in clinical settings. PMID:25110412

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  5. BMP signaling balances murine myeloid potential through SMAD-independent p38MAPK and NOTCH pathways.

    PubMed

    Cook, Brandoch D; Evans, Todd

    2014-07-17

    Bone morphogenetic protein (BMP) signaling regulates early hematopoietic development, proceeding from mesoderm patterning through the progressive commitment and differentiation of progenitor cells. The BMP pathway signals largely through receptor-mediated activation of Mothers Against Decapentaplegic homolog (SMAD) proteins, although alternate pathways are modulated through various components of mitogen-activated protein kinase (MAPK) signaling. Using a conditional, short hairpin RNA (shRNA)-based knockdown system in the context of differentiating embryonic stem cells (ESCs), we demonstrated previously that Smad1 promotes hemangioblast specification, but then subsequently restricts primitive progenitor potential. Here we show that co-knockdown of Smad5 restores normal progenitor potential of Smad1-depleted cells, suggesting opposing functions for Smad1 and Smad5. This balance was confirmed by cotargeting Smad1/5 with a specific chemical antagonist, LDN193189 (LDN). However, we discovered that LDN treatment after hemangioblast commitment enhanced primitive myeloid potential. Moreover, inhibition with LDN (but not SMAD depletion) increased expression of Delta-like ligands Dll1 and Dll3 and NOTCH activity; abrogation of NOTCH activity restored LDN-enhanced myeloid potential back to normal, corresponding with expression levels of the myeloid master regulator, C/EBPα. LDN but not SMAD activity was also associated with activation of the p38MAPK pathway, and blocking this pathway was sufficient to enhance myelopoiesis. Therefore, NOTCH and p38MAPK pathways balance primitive myeloid progenitor output downstream of the BMP pathway. PMID:24894772

  6. A Specific Oligodeoxynucleotide Promotes the Differentiation of Osteoblasts via ERK and p38 MAPK Pathways

    PubMed Central

    Hou, Xu; Shen, Yuqin; Zhang, Chao; Zhang, Liru; Qin, Yanyan; Yu, Yongli; Wang, Liying; Sun, Xinhua

    2012-01-01

    A specific oligodeoxynucleotide (ODN), ODN MT01, was found to have positive effects on the proliferation and activation of the osteoblast-like cell line MG 63. In this study, the detailed signaling pathways in which ODN MT01 promoted the differentiation of osteoblasts were systematically examined. ODN MT01 enhanced the expression of osteogenic marker genes, such as osteocalcin and type I collagen. Furthermore, ODN MT01 activated Runx2 phosphorylation via ERK1/2 mitogen-activated protein kinase (MAPK) and p38 MAPK. Consistently, ODN MT01 induced up-regulation of osteocalcin, alkaline phosphatase (ALP) and type I collagen, which was inhibited by pre-treatment with the ERK1/2 inhibitor U0126 and the p38 inhibitor SB203580. These results suggest that the ERK1/2 and p38 MAPK pathways, as well as Runx2 activation, are involved in ODN MT01-induced up-regulation of osteocalcin, type I collagen and the activity of ALP in MG 63 cells. PMID:22942680

  7. Involvement of p38MAPK-ATF2 signaling pathway in alternariol induced DNA polymerase β expression

    PubMed Central

    ZHAO, JIMIN; MA, JUNFEN; LU, JING; JIANG, YANAN; ZHANG, YANYAN; ZHANG, XIAOYAN; ZHAO, JUN; YANG, HONGYAN; HUANG, YOUTIAN; ZHAO, MINGYAO; LIU, KANGDONG; DONG, ZIMING

    2016-01-01

    Base excision repair (BER) systems are important for maintaining the integrity of genomes in mammalian cells. Aberrant DNA bases or broken single strands can be repaired by BER. Consequently, DNA lesions, which may be caused by cancer and aging, have a close association with BER procedure. DNA polymerase β (polβ) is a critical BER enzyme that can excise 5′-sugar phosphate prior to adding a nucleotide in the gap by its function as a DNA polymerase in the BER process. However, DNA polβ is an error-prone DNA polymerase, and overexpressing polβ increases the cellular spontaneous mutation rate. DNA polβ overexpression has been identified in various human tumors, which implies that DNA polβ overexpression has a close association with tumorigenesis. The present study showed that alternariol (AOH), a secondary product of a fungus that is found in grains and fruits, could cause DNA damage to NIH3T3 cells in a single cell gel electrophoresis, and that 2, 10 and 20 µM AOH induced DNA polβ overexpression in a dose-dependent manner. In the process, the level of phosphorylation of mitogen-activated protein kinase 14 (p38) mitogen-activated protein kinase (MAPK) and activating transcription factor 2 (ATF2) was increased. In addition, SB203580, a p38MAPK inhibitor, resulted in decreased DNA polβ expression. Small hairpin RNA-p38MAPK had the same effect; notably, DNA polβ expression was downregulated in p38MAPK knockdown cells. These data suggest that the p38MAPK-ATF2 signaling pathway may be involved in DNA polβ expression induced by AOH. PMID:27347199

  8. Combined inhibition of p38 and Akt signaling pathways abrogates cyclosporine A-mediated pathogenesis of aggressive skin SCCs

    SciTech Connect

    Arumugam, Aadithya; Walsh, Stephanie B.; Xu, Jianmin; Afaq, Farrukh; Elmets, Craig A.; Athar, Mohammad

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer p38 and Akt are the crucial molecular targets in the pathogenesis of SCCs in OTRs. Black-Right-Pointing-Pointer Combined inhibition of these targets diminished tumor growth by 90%. Black-Right-Pointing-Pointer Inhibition of these targets act through downregulating mTOR signaling pathway. -- Abstract: Non-melanoma skin cancers (NMSCs) are the most common neoplasm in organ transplant recipients (OTRs). These cancers are more invasive and metastatic as compared to those developed in normal cohorts. Previously, we have shown that immunosuppressive drug, cyclosporine A (CsA) directly alters tumor phenotype of cutaneous squamous cell carcinomas (SCCs) by activating TGF-{beta} and TAK1/TAB1 signaling pathways. Here, we identified novel molecular targets for the therapeutic intervention of these SCCs. We observed that combined blockade of Akt and p38 kinases-dependent signaling pathways in CsA-promoted human epidermoid carcinoma A431 xenograft tumors abrogated their growth by more than 90%. This diminution in tumor growth was accompanied by a significant decrease in proliferation and an increase in apoptosis. The residual tumors following the combined treatment with Akt inhibitor triciribine and p38 inhibitors SB-203580 showed significantly diminished expression of phosphorylated Akt and p38 and these tumors were less invasive and highly differentiated. Diminished tumor invasiveness was associated with the reduced epithelial-mesenchymal transition as ascertained by the enhanced E-cadherin and reduced vimentin and N-cadherin expression. Consistently, these tumors also manifested reduced MMP-2/9. The decreased p-Akt expression was accompanied by a significant reduction in p-mTOR. These data provide first important combinatorial pharmacological approach to block the pathogenesis of CsA-induced highly aggressive cutaneous neoplasm in OTRs.

  9. CD14 Signaling Restrains Chronic Inflammation through Induction of p38-MAPK/SOCS-Dependent Tolerance

    PubMed Central

    Sahay, Bikash; Patsey, Rebeca L.; Eggers, Christian H.; Salazar, Juan C.; Radolf, Justin D.; Sellati, Timothy J.

    2009-01-01

    Current thinking emphasizes the primacy of CD14 in facilitating recognition of microbes by certain TLRs to initiate pro-inflammatory signaling events and the importance of p38-MAPK in augmenting such responses. Herein, this paradigm is challenged by demonstrating that recognition of live Borrelia burgdorferi not only triggers an inflammatory response in the absence of CD14, but one that is, in part, a consequence of altered PI3K/AKT/p38-MAPK signaling and impaired negative regulation of TLR2. CD14 deficiency results in increased localization of PI3K to lipid rafts, hyperphosphorylation of AKT, and reduced activation of p38. Such aberrant signaling leads to decreased negative regulation by SOCS1, SOCS3, and CIS, thereby compromising the induction of tolerance in macrophages and engendering more severe and persistent inflammatory responses to B. burgdorferi. Importantly, these altered signaling events and the higher cytokine production observed can be mimicked through shRNA and pharmacological inhibition of p38 activity in CD14-expressing macrophages. Perturbation of this CD14/p38-MAPK-dependent immune regulation may underlie development of infectious chronic inflammatory syndromes. PMID:20011115

  10. Fucoidan Stimulates Monocyte Migration via ERK/p38 Signaling Pathways and MMP9 Secretion.

    PubMed

    Sapharikas, Elene; Lokajczyk, Anna; Fischer, Anne-Marie; Boisson-Vidal, Catherine

    2015-07-01

    Critical limb ischemia (CLI) induces the secretion of paracrine signals, leading to monocyte recruitment and thereby contributing to the initiation of angiogenesis and tissue healing. We have previously demonstrated that fucoidan, an antithrombotic polysaccharide, promotes the formation of new blood vessels in a mouse model of hindlimb ischemia. We examined the effect of fucoidan on the capacity of peripheral blood monocytes to adhere and migrate. Monocytes negatively isolated with magnetic beads from peripheral blood of healthy donors were treated with fucoidan. Fucoidan induced a 1.5-fold increase in monocyte adhesion to gelatin (p < 0.05) and a five-fold increase in chemotaxis in Boyden chambers (p < 0.05). Fucoidan also enhanced migration 2.5-fold in a transmigration assay (p < 0.05). MMP9 activity in monocyte supernatants was significantly enhanced by fucoidan (p < 0.05). Finally, Western blot analysis of fucoidan-treated monocytes showed upregulation of ERK/p38 phosphorylation. Inhibition of ERK/p38 phosphorylation abrogated fucoidan enhancement of migration (p < 0.01). Fucoidan displays striking biological effects, notably promoting monocyte adhesion and migration. These effects involve the ERK and p38 pathways, and increased MMP9 activity. Fucoidan could improve critical limb ischemia by promoting monocyte recruitment. PMID:26133555

  11. Fucoidan Stimulates Monocyte Migration via ERK/p38 Signaling Pathways and MMP9 Secretion

    PubMed Central

    Sapharikas, Elene; Lokajczyk, Anna; Fischer, Anne-Marie; Boisson-Vidal, Catherine

    2015-01-01

    Critical limb ischemia (CLI) induces the secretion of paracrine signals, leading to monocyte recruitment and thereby contributing to the initiation of angiogenesis and tissue healing. We have previously demonstrated that fucoidan, an antithrombotic polysaccharide, promotes the formation of new blood vessels in a mouse model of hindlimb ischemia. We examined the effect of fucoidan on the capacity of peripheral blood monocytes to adhere and migrate. Monocytes negatively isolated with magnetic beads from peripheral blood of healthy donors were treated with fucoidan. Fucoidan induced a 1.5-fold increase in monocyte adhesion to gelatin (p < 0.05) and a five-fold increase in chemotaxis in Boyden chambers (p < 0.05). Fucoidan also enhanced migration 2.5-fold in a transmigration assay (p < 0.05). MMP9 activity in monocyte supernatants was significantly enhanced by fucoidan (p < 0.05). Finally, Western blot analysis of fucoidan-treated monocytes showed upregulation of ERK/p38 phosphorylation. Inhibition of ERK/p38 phosphorylation abrogated fucoidan enhancement of migration (p < 0.01). Fucoidan displays striking biological effects, notably promoting monocyte adhesion and migration. These effects involve the ERK and p38 pathways, and increased MMP9 activity. Fucoidan could improve critical limb ischemia by promoting monocyte recruitment. PMID:26133555

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

    PubMed

    Mao, Jiamin; Yang, Jianbing; Zhang, Yan; Li, Ting; Wang, Cheng; Xu, Lingfei; Hu, Qiaoyun; Wang, Xiaoke; Jiang, Shengyang; Nie, Xiaoke; Chen, Gang

    2016-07-15

    Arsenic is a widely distributed toxic metalloid all over the world. Inorganic arsenic species are supposed to affect astrocytic functions and to cause neuron apoptosis in CNS. Microglias are the key cell type involved in innate immune responses in CNS, and microglia activation has been linked to inflammation and neurotoxicity. In this study, using ELISA, we showed that Arsenic trioxide up-regulated the expression and secretion of IL-1β in a dose-dependent manner and a time-dependent manner in cultured HAPI microglia cells. The secretion of IL-1β caused the apoptosis of SH-SY5Y. These pro-inflammatory responses were inhibited by the STAT3 blocker, AG490 and P38/JNK MAPK blockers SB202190, SP600125. Further, Arsenic trioxide exposure could induce phosphorylation and activation of STAT3, and the translocation of STAT3 from the cytosol to the nucleus in this HAPI microglia cell line. Thus, the STAT3 signaling pathway can be activated after Arsenic trioxide treatment. However, P38/JNK MAPK blockers SB202190, SP600125 also obviously attenuated STAT3 activation and transnuclear transport induced by Arsenic trioxide. In concert with these results, we highlighted that the secretion of IL-1β and STAT3 activation induced by Arsenic trioxide can be mediated by elevation of P38/JNK MAPK in HAPI microglia cells and then induced the toxicity of neurons. PMID:27174766

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

    PubMed

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

    2016-02-15

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

  14. Transforming growth factor-β1 induces fibrosis in rat meningeal mesothelial cells via the p38 signaling pathway.

    PubMed

    Yue, Xue-Jing; Guo, Yan; Yang, Hai-Jie; Feng, Zhi-Wei; Li, Tong; Xu, Yu-Ming

    2016-08-01

    Leptomeningeal fibrosis is important in the pathogenesis of communicating hydrocephalus following subarachnoid hemorrhage; however, the underlying mechanisms of leptomeningeal fibrosis remain largely unclear. In the present study, primary meningeal mesothelial cells (MMCs) were used as a cell model to investigate the effect of transforming growth factor‑β1 (TGF‑β1) on leptomeningeal fibrosis. Firstly, primary MMCs were isolated from rat brains and characterized by immunofluorescene, staining positive for keratin and vimentin, but negative for factor VIII. Upon TGF‑β1 treatment, MMCs were induced to express connective tissue growth factor (CTGF), an indicator of fibrosis, in a dose‑dependent manner. Furthermore, p38 mitogen‑activated protein kinase (MAPK) signaling was significantly activated by TGF‑β1. However, in the presence of a p38 MAPK inhibitor, TGF‑β1‑induced CTGF expression was markedly suppressed. Together, these data suggest that TGF‑β1 could induce fibrosis of MMCs via the p38 MAPK signaling pathway, providing a novel potential target for intervention in TGF‑β1‑induced leptomeningeal fibrosis. PMID:27314440

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

    PubMed

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

    2016-01-01

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

  16. FGF and stress regulate CREB and ATF-1 via a pathway involving p38 MAP kinase and MAPKAP kinase-2.

    PubMed Central

    Tan, Y; Rouse, J; Zhang, A; Cariati, S; Cohen, P; Comb, M J

    1996-01-01

    Fibroblast growth factor (FGF) activates a protein kinase cascade in SK-N-MC cells that regulates gene expression at a cyclic-AMP response element (CRE) by stimulating the transcriptional activity of CREB. The activation of CREB is prevented by a dominant negative mutant of Ras and triggered via the same site (Ser133) that becomes phosphorylated in response to cyclic AMP and Ca2+. However, the effect of FGF is not mediated by cyclic AMP-dependent protein kinase, TPA-sensitive isoforms of protein kinase-C, p70S6K or p90rsk (all of which phosphorylate CREB at Ser133 in vitro). Instead, we identify the FGF-stimulated CREB kinase as MAP kinase-activated protein (MAPKAP) kinase-2, an enzyme that lies immediately downstream of p38 MAP kinase, in a pathway that is also stimulated by cellular stresses. We show that MAPKAP kinase-2 phosphorylates CREB at Ser133 in vitro, that the FGF- or stress-induced activation of MAPKAP kinase-2 and phosphorylation of CREB and ATF-1 are prevented by similar concentrations of the specific p38 MAP kinase inhibitor SB 203580, and that MAPKAP kinase-2 is the only detectable SB 203580-sensitive CREB kinase in SK-N-MC cell extracts. We also show that transfection of RK/p38 MAP kinase in SK-N-MC cells, but not transfection of p44 MAP kinase, activates Gal4-CREB-dependent transcription via Ser133. These findings identify a new growth factor and stress-activated signaling pathway that regulates gene expression at the CRE. Images PMID:8887554

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

    PubMed

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

    2016-07-01

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

  18. Low-Intensity Pulsed Ultrasound Affects Chondrocyte Extracellular Matrix Production via an Integrin-Mediated p38 MAPK Signaling Pathway.

    PubMed

    Xia, Peng; Ren, Shasha; Lin, Qiang; Cheng, Kai; Shen, Shihao; Gao, Mingxia; Li, Xueping

    2015-06-01

    Although low-intensity pulsed ultrasound (LIPUS) regulates p38 mitogen-activated protein kinase (MAPK) and promotes cartilage repair in osteoarthritis, the role of integrin-mediated p38 MAPK in the effect of LIPUS on extracellular matrix (ECM) production of normal and OA chondrocytes remains unknown. The aim of this study was to investigate whether LIPUS affects ECM production in normal and OA rabbit chondrocytes through an integrin-p38 signaling pathway. A rabbit model of OA was established by anterior cruciate ligament transection, and chondrocytes were isolated from normal or OA cartilage and cultured in vitro. Chondrocytes were treated with LIPUS and then pre-incubated with the integrin inhibitor GRGDSP or the p38 inhibitor SB203580. Expression of type II collagen, MMP-13, integrin β1, p38 and phosphorylated p38 was assessed by Western blot analysis. We found that type II collagen and integrin β1 were upregulated (p < 0.05), whereas MMP-13 was downregulated (p < 0.05) in normal and OA chondrocytes. Furthermore, phosphorylated p38 was upregulated (p < 0.05) in normal chondrocytes, but downregulated (p < 0.05) in OA chondrocytes after LIPUS stimulation. Pre-incubation of chondrocytes with the integrin inhibitor disrupted the effects of LIPUS on normal and OA chondrocytes. Pre-incubation of chrondocytes with the p38 inhibitor reduced the effects of LIPUS on normal chondrocytes, but had no impact on OA chondrocytes. Our findings suggest that the integrin-p38 MAPK signaling pathway plays an important role in LIPUS-mediated ECM production in chondrocytes. PMID:25736607

  19. Calcitonin gene-related peptide contributes to peripheral nerve injury-induced mechanical hypersensitivity through CCL5 and p38 pathways.

    PubMed

    Malon, Jennifer T; Cao, Ling

    2016-08-15

    The role of calcitonin gene related peptide (CGRP) in neuropathic pain was investigated in a mouse model of neuropathic pain, spinal nerve L5 transection (L5Tx). Intrathecal injection (i.t.) of CGRP8-37, a CGRP antagonist, significantly reduced L5Tx-induced mechanical hypersensitivity and lumbar spinal cord CCL5 expression. i.t. injection of a CCL5 neutralizing antibody significantly inhibited L5Tx-induced mechanical hypersensitivity. Further, pre-treatment with a p38-inhibitor, SB203580, was able to reduce CGRP-induced mechanical hypersensitivity, but not CGRP-induced CCL5 production. Our data indicate that CGRP can play its pro-nociceptive role through both a spinal cord CCL5-dependent, p38-independent pathway, and a p38-depenented, CCL5-independent pathway. PMID:27397078

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

    PubMed Central

    Koodie, Lisa; Ramakrishnan, Sundaram; Roy, Sabita

    2010-01-01

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

  1. p38 MAPKs regulate the expression of genes in the dopamine synthesis pathway through phosphorylation of NR4A nuclear receptors.

    PubMed

    Sekine, Yusuke; Takagahara, Shuichi; Hatanaka, Ryo; Watanabe, Takeshi; Oguchi, Haruka; Noguchi, Takuya; Naguro, Isao; Kobayashi, Kazuto; Tsunoda, Makoto; Funatsu, Takashi; Nomura, Hiroshi; Toyoda, Takeshi; Matsuki, Norio; Kuranaga, Erina; Miura, Masayuki; Takeda, Kohsuke; Ichijo, Hidenori

    2011-09-01

    In Drosophila, the melanization reaction is an important defense mechanism against injury and invasion of microorganisms. Drosophila tyrosine hydroxylase (TH, also known as Pale) and dopa decarboxylase (Ddc), key enzymes in the dopamine synthesis pathway, underlie the melanin synthesis by providing the melanin precursors dopa and dopamine, respectively. It has been shown that expression of Drosophila TH and Ddc is induced in various physiological and pathological conditions, including bacterial challenge; however, the mechanism involved has not been fully elucidated. Here, we show that ectopic activation of p38 MAPK induces TH and Ddc expression, leading to upregulation of melanization in the Drosophila cuticle. This p38-dependent melanization was attenuated by knockdown of TH and Ddc, as well as by that of Drosophila HR38, a member of the NR4A family of nuclear receptors. In mammalian cells, p38 phosphorylated mammalian NR4As and Drosophila HR38 and potentiated these NR4As to transactivate a promoter containing NR4A-binding elements, with this transactivation being, at least in part, dependent on the phosphorylation. This suggests an evolutionarily conserved role for p38 MAPKs in the regulation of NR4As. Thus, p38-regulated gene induction through NR4As appears to function in the dopamine synthesis pathway and may be involved in immune and stress responses. PMID:21878507

  2. A C. elegans p38 MAP kinase pathway mutant protects from dopamine, methamphetamine, and MDMA toxicity

    PubMed Central

    Schreiber, Matthew A.; McIntire, Steven L.

    2011-01-01

    Biogenic amine systems are damaged by amphetamine abuse and in Parkinson's disease. The mechanisms mediating this damage are of high importance because of the public health impact of these problems. Here we have taken advantage of the C. elegans nematode model system to investigate genetic modifiers of biogenic amine toxicity. In a forward genetic screen, we identified a mutant resistant to the toxic effects of dopamine. This mutant was also resistant to toxic doses of methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA). In addition, this mutation conferred resistance to 6-hydroxydopamine damage to dopaminergic neurons in a Parkinson's disease model. Resistance was due to a mutation in the nsy-1 gene, orthologous to the mammalian ASK-1 MAPKKK. NSY-1 is in the highly conserved p38 MAP kinase pathway, which plays a crucial role in C. elegans innate immunity, suggesting that this pathway may play a role in biogenic amine toxicity system damage due to amphetamines and in the pathogenesis of Parkinson's disease in higher organisms. PMID:21565252

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  5. GADD45B mediates podocyte injury in zebrafish by activating the ROS-GADD45B-p38 pathway

    PubMed Central

    Chen, Z; Wan, X; Hou, Q; Shi, S; Wang, L; Chen, P; Zhu, X; Zeng, C; Qin, W; Zhou, W; Liu, Z

    2016-01-01

    GADD45 gene has been implicated in cell cycle arrest, cell survival or apoptosis in a cell type specific and context-dependent manner. Members of GADD45 gene family have been found differentially expressed in several podocyte injury models, but their roles in podocytes are unclear. Using an in vivo zebrafish model of inducible podocyte injury that we have previously established, we found that zebrafish orthologs of gadd45b were induced upon the induction of podocyte injury. Podocyte-specific overexpression of zebrafish gadd45b exacerbated edema, proteinuria and foot-process effacement, whereas knockdown of gadd45b by morpholino-oligos in zebrafish larvae ameliorated podocyte injury. We then explored the role of GADD45B induction in podocyte injury using in vitro podocyte culture. We confirmed that GADD45B was significantly upregulated during the early phase of podocyte injury in cultured human podocytes and that podocyte apoptosis induced by TGF-β and puromycin aminonucleoside (PAN) was aggravated by GADD45B overexpression but ameliorated by shRNA-mediated GADD45B knockdown. We also showed that ROS inhibitor NAC suppressed PAN-induced GADD45B expression and subsequent activation of p38 MAPK pathway in podocytes and that inhibition of GADD45B diminished PAN-induced p38 MAPK activation. Taken together, our findings demonstrated that GADD45B has an important role in podocyte injury and may be a therapeutic target for the management of podocyte injury in glomerular diseases. PMID:26794661

  6. Doxycycline Suppresses Microglial Activation by Inhibiting the p38 MAPK and NF-kB Signaling Pathways.

    PubMed

    Santa-Cecília, Flávia V; Socias, Benjamin; Ouidja, Mohand O; Sepulveda-Diaz, Julia E; Acuña, Leonardo; Silva, Rangel L; Michel, Patrick P; Del-Bel, Elaine; Cunha, Thiago M; Raisman-Vozari, Rita

    2016-05-01

    In neurodegenerative diseases, the inflammatory response is mediated by activated glial cells, mainly microglia, which are the resident immune cells of the central nervous system. Activated microglial cells release proinflammatory mediators and neurotoxic factors that are suspected to cause or exacerbate these diseases. We recently demonstrated that doxycycline protects substantia nigra dopaminergic neurons in an animal model of Parkinson's disease. This effect was associated with a reduction of microglial cell activation, which suggests that doxycycline may operate primarily as an anti-inflammatory drug. In the present study, we assessed the anti-inflammatory potential of doxycycline using lipopolysaccharide (LPS)-activated primary microglial cells in culture as a model of neuroinflammation. Doxycycline attenuated the expression of key activation markers in LPS-treated microglial cultures in a concentration-dependent manner. More specifically, doxycycline treatment lowered the expression of the microglial activation marker IBA-1 as well as the production of ROS, NO, and proinflammatory cytokines (TNF-α and IL-1β). In primary microglial cells, we also found that doxycycline inhibits LPS-induced p38 MAP kinase phosphorylation and NF-kB nuclear translocation. The present results indicate that the effect of doxycycline on LPS-induced microglial activation probably occurs via the modulation of p38 MAP kinase and NF-kB signaling pathways. These results support the idea that doxycycline may be useful in preventing or slowing the progression of PD and other neurodegenerative diseases that exhibit altered glia function. PMID:26745968

  7. Induction of the pi class of glutathione S-transferase by carnosic acid in rat Clone 9 cells via the p38/Nrf2 pathway.

    PubMed

    Lin, Chia-Yuan; Wu, Chi-Rei; Chang, Shu-Wei; Wang, Yu-Jung; Wu, Jia-Jiuan; Tsai, Chia-Wen

    2015-06-01

    Induction of phase II enzymes is important in cancer chemoprevention. We compared the effect of rosemary diterpenes on the expression of the pi class of glutathione S-transferase (GSTP) in rat liver Clone 9 cells and the signaling pathways involved. Culturing cells with 1, 5, 10, or 20 μM carnosic acid (CA) or carnosol (CS) for 24 h in a dose-dependent manner increased the GSTP expression. CA was more potent than CS. The RNA level and the enzyme activity of GSTP were also enhanced by CA treatment. Treatment with 10 μM CA highly induced the reporter activity of the enhancer element GPEI. Furthermore, CA markedly increased the translocation of nuclear factor erythroid-2 related factor 2 (Nrf2) from the cytosol to the nucleus after 30 to 60 min. CA the stimulated the protein induction of p38, nuclear Nrf2, and GSTP was diminished in the presence of SB203580 (a p38 inhibitor). In addition, SB203580 pretreatment or silencing of Nrf2 by siRNA suppressed the CA-induced GPEI-DNA binding activity and GSTP protein expression. Knockdown of p38 or Nrf2 by siRNA abolished the activation of p38 and Nrf2 as well as the protein induction and enzyme activity of GSTP by CA. These results suggest that CA up-regulates the expression and enzyme activity of GSTP via the p38/Nrf2/GPEI pathway. PMID:25974399

  8. CPG-ODN-INDUCED NITRIC OXIDE PRODUCTION IS MEDIATED THROUGH CLATHRIN-DEPENDENT ENDOCYTOSIS, ENDOSOMAL MATURATION, AND ACTIVATION OF PKC, MEK1/2 AND P38 MAPK, AND NF-KB PATHWAYS IN AVIAN MACROPHAGE CELLS (HD11)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have characterized the nitric oxide (NO) induction by CpG oligodeoxydinucleotide (CpG-ODN) and lipopolysaccharide (LPS) in an avian macrophage cell line (HD11) and evaluated roles of signal transduction pathways by using selective inhibitors. Our results indicate while CpG-ODN and LPS both stimu...

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

    PubMed Central

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

    2016-01-01

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

  10. Interplay between Akt and p38 MAPK pathways in the regulation of renal tubular cell apoptosis associated with diabetic nephropathy

    PubMed Central

    Song, Ye; Jin, Shunying; Barati, Michelle T.; Wu, Rui; Kausar, Hina; Tan, Yi; Wang, Yuehui; Zhou, Guihua; Klein, Jon B.; Li, Xiaokun

    2010-01-01

    Hyperglycemia induces p38 MAPK-mediated renal proximal tubular cell (RPTC) apoptosis. The current study hypothesized that alteration of the Akt signaling pathway by hyperglycemia may contribute to p38 MAPK activation and development of diabetic nephropathy. Immunoblot analysis demonstrated a hyperglycemia-induced increase in Akt phosphorylation in diabetic kidneys at 1 mo, peaking at 3 mo, and dropping back to baseline by 6 mo. Immunohistochemical staining with anti-pAkt antisera localized Akt phosphorylation to renal tubules. Maximal p38 MAPK phosphorylation was detected concomitant with increase in terminal uridine deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells and caspase-3 activity in 6-mo diabetic kidneys. Exposure of cultured RPTCs to high glucose (HG; 22.5 mM) significantly increased Akt phosphorylation at 3, 6, and 9 h, and decreased thereafter. In contrast, p38 MAPK phosphorylation was detected between 9 and 48 h of HG treatment. Increased p38 MAPK activation at 24 and 48 h coincided with increased apoptosis, demonstrated by increased caspase-3 activity at 24 h and increased TUNEL-positive cells at 48 h of HG exposure. Blockade of p38 cascade with SB203850 inhibited HG-induced caspase-3 activation and TUNEL-positive cells. Overexpression of constitutively active Akt abrogated HG-induced p38 MAPK phosphorylation and RPTC apoptosis. In addition, blockade of the phosphatidylinositol-3 kinase/Akt pathway with LY294002 and silencing of Akt expression with Akt small interfering RNA induced p38 MAPK phosphorylation in the absence of HG. These results collectively suggest that downregulation of Akt activation during long-term hyperglycemia contributes to enhanced p38 MAPK activation and RPTC apoptosis. Mechanism of downregulation of Akt activation in 6-mo streptozotocin diabetic kidneys was attributed to decreased Akt-heat shock protein (Hsp) 25, Akt-p38 interaction, and decreased PTEN activity. Thus PTEN or Hsp25 could serve

  11. Interplay between Akt and p38 MAPK pathways in the regulation of renal tubular cell apoptosis associated with diabetic nephropathy.

    PubMed

    Rane, Madhavi J; Song, Ye; Jin, Shunying; Barati, Michelle T; Wu, Rui; Kausar, Hina; Tan, Yi; Wang, Yuehui; Zhou, Guihua; Klein, Jon B; Li, Xiaokun; Cai, Lu

    2010-01-01

    Hyperglycemia induces p38 MAPK-mediated renal proximal tubular cell (RPTC) apoptosis. The current study hypothesized that alteration of the Akt signaling pathway by hyperglycemia may contribute to p38 MAPK activation and development of diabetic nephropathy. Immunoblot analysis demonstrated a hyperglycemia-induced increase in Akt phosphorylation in diabetic kidneys at 1 mo, peaking at 3 mo, and dropping back to baseline by 6 mo. Immunohistochemical staining with anti-pAkt antisera localized Akt phosphorylation to renal tubules. Maximal p38 MAPK phosphorylation was detected concomitant with increase in terminal uridine deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells and caspase-3 activity in 6-mo diabetic kidneys. Exposure of cultured RPTCs to high glucose (HG; 22.5 mM) significantly increased Akt phosphorylation at 3, 6, and 9 h, and decreased thereafter. In contrast, p38 MAPK phosphorylation was detected between 9 and 48 h of HG treatment. Increased p38 MAPK activation at 24 and 48 h coincided with increased apoptosis, demonstrated by increased caspase-3 activity at 24 h and increased TUNEL-positive cells at 48 h of HG exposure. Blockade of p38 cascade with SB203850 inhibited HG-induced caspase-3 activation and TUNEL-positive cells. Overexpression of constitutively active Akt abrogated HG-induced p38 MAPK phosphorylation and RPTC apoptosis. In addition, blockade of the phosphatidylinositol-3 kinase/Akt pathway with LY294002 and silencing of Akt expression with Akt small interfering RNA induced p38 MAPK phosphorylation in the absence of HG. These results collectively suggest that downregulation of Akt activation during long-term hyperglycemia contributes to enhanced p38 MAPK activation and RPTC apoptosis. Mechanism of downregulation of Akt activation in 6-mo streptozotocin diabetic kidneys was attributed to decreased Akt-heat shock protein (Hsp) 25, Akt-p38 interaction, and decreased PTEN activity. Thus PTEN or Hsp25 could serve

  12. Docosahexenoic acid treatment ameliorates cartilage degeneration via a p38 MAPK-dependent mechanism

    PubMed Central

    WANG, ZHENZHONG; GUO, AI; MA, LIFENG; YU, HAOMIAO; ZHANG, LIANG; MENG, HAI; CUI, YINPENG; YU, FEI; YANG, BO

    2016-01-01

    Osteoarthritis (OA) is a common chronic inflammatory disease, characterized by cartilage degradation. The aberrant expression of matrix metalloproteinase-13 (MMP-13) plays a vital role in the pathogenesis of OA. The anti-inflammatory property of docosahexenoic acid (DHA) was previously revealed and showed that DHA retards the progress of many types of inflammatory disease. To evaluate the prophylactic function of DHA in OA, the effect of DHA on cartilage degeneration was assessed in interleukin-1β (IL-1β) stimulated human chondrosarcoma SW1353 cells or a rat model of adjuvant-induced arthritis (AIA). The safe concentration range (0–50 µg/ml in vitro) of DHA was determined by flow cytometry and MTT assay. The inhibitory effects of DHA on MMP-13 mRNA and protein expression were confirmed by RT-qPCR, ELISA and western blotting. Furthermore, findings of an in vivo study showed that DHA can increase the thickness of articular cartilage and decrease MMP-13 expression in cartilage matrix in a rat AIA model. We also revealed the mechanism by which DHA ameliorates cartilage degeneration from OA. The DHA-mediated inhibition of MMP-13 expression was partially attributed to the inactivation of the p38 mitogen-activated protein kinases pathway by suppressing p-p38 in IL-1β-stimulated SW1353 cells and a rat AIA model. Our findings suggested that DHA is a promising therapeutic agent that may be used for the prevention and treatment of OA. PMID:27082436

  13. Nur77 inhibits oxLDL induced apoptosis of macrophages via the p38 MAPK signaling pathway.

    PubMed

    Shao, Qin; Han, Fei; Peng, Shi; He, Ben

    2016-03-18

    The interaction between macrophages and oxLDL plays a crucial role in the initiation and progression of atherosclerosis. As a key initiator in a number of plaque promoting processes, oxLDL induces variable effects such as cell apoptosis or proliferation. Orphan nuclear receptor Nur77 is potently induced in macrophages by diverse stimuli, suggesting that it is of importance in vascular inflammation resulting in atherosclerosis, but whether Nur77 induction is detrimental or protective is unclear. In our study, we explore the role of Nur77 in the regulation of oxLDL-induced macrophage apoptosis and the signaling pathways that are involved. We found that oxLDL induced Nur77 expression in a dose and time dependent fashion, and cell viability was decreased in parallel. To determine whether Nur77 induction contributes to the loss of cell viability or is a protective mechanism, the effect of Nur77 overexpression was examined. Importantly, Nur77 overexpression inhibited the oxLDL-induced decrease of cell viability, inhibited the production of apoptotic bodies and restored DNA synthesis following oxLDL exposure. Furthermore, we found that Nur77 induction is mediated through the p38 MAPK signaling pathway. After pretreatment with SB203580, cell viability was decreased, the expression of CyclinA2 and PCNA was attenuated and the percentage of cell apoptosis was enhanced. Likewise, Nur77 overexpression increased the expression of the cell cycle genes PCNA and p21, and attenuated the increase in caspase-3. On the other hand, knockdown of Nur77 expression by specific siRNA resulted in the increased expression of caspase 3. The results demonstrate that Nur77 is induced by oxLDL via the p38 MAPK signaling pathway, which is involved in the regulation of cell survival. Nur77 enhanced cell survival via suppressing apoptosis, without affecting cell proliferation of activated macrophages, which may be beneficial in patients with atherosclerosis. PMID:26768365

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

    PubMed

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

    2016-06-25

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

  15. The Developmental Intestinal Regulator ELT-2 Controls p38-Dependent Immune Responses in Adult C. elegans

    PubMed Central

    Block, Dena H. S.; Twumasi-Boateng, Kwame; Kang, Hae Sung; Carlisle, Jolie A.; Hanganu, Alexandru; Lai, Ty Yu-Jen; Shapira, Michael

    2015-01-01

    GATA transcription factors play critical roles in cellular differentiation and development. However, their roles in mature tissues are less understood. In C. elegans larvae, the transcription factor ELT-2 regulates terminal differentiation of the intestine. It is also expressed in the adult intestine, where it was suggested to maintain intestinal structure and function, and where it was additionally shown to contribute to infection resistance. To study the function of elt-2 in adults we characterized elt-2-dependent gene expression following its knock-down specifically in adults. Microarray analysis identified two ELT-2-regulated gene subsets: one, enriched for hydrolytic enzymes, pointed at regulation of constitutive digestive functions as a dominant role of adult elt-2; the second was enriched for immune genes that are induced in response to Pseudomonas aeruginosa infection. Focusing on the latter, we used genetic analyses coupled to survival assays and quantitative RT-PCR to interrogate the mechanism(s) through which elt-2 contributes to immunity. We show that elt-2 controls p38-dependent gene induction, cooperating with two p38-activated transcription factors, ATF-7 and SKN-1. This demonstrates a mechanism through which the constitutively nuclear elt-2 can impact induced responses, and play a dominant role in C. elegans immunity. PMID:26016853

  16. Stearoyl lysophosphatidylcholine enhances the phagocytic ability of macrophages through the AMP-activated protein kinase/p38 mitogen activated protein kinase pathway.

    PubMed

    Quan, Hui; Hur, Young-Hoe; Xin, Chun; Kim, Joung-Min; Choi, Jeong-Il; Kim, Man-Young; Bae, Hong-Beom

    2016-10-01

    A previous study showed that stearoyl lysophosphatidylcholine (sLPC) suppressed extracellular high mobility group box 1 translocation in macrophages stimulated with lipopolysaccharide through AMP-activated protein kinase (AMPK) activation. In the present study, we investigated whether sLPC-induced AMPK activation could enhance macrophages phagocytosis of bacteria. We found that sLPC increased phosphorylation of AMPK and acetyl-CoA carboxylase, a downstream target of AMPK, in a time- and dose-dependent manner in macrophages. Furthermore, sLPC increased the uptake of FITC-conjugated Escherichia coli by macrophages in a dose-dependent manner, and treatment with an AMPK inhibitor (compound C) or siRNA to AMPKα1 reversed this uptake. sLPC increased the phosphorylation of p38 mitogen-activated protein kinase (MAPK), but inhibition of AMPK activity with compound C or siRNA to AMPKα1 prevented the sLPC-induced increase in p38 MAPK phosphorylation. SB203580, a p38 MAPK inhibitor, decreased sLPC-induced phagocytosis. In vivo, systemic administration of sLPC to mice led to increased AMPK and p38 MAPK activity in the lung and to increased phagocytosis of fluorescent E. coli in bronchoalveolar lavage cells. These results suggest that sLPC increases macrophages phagocytosis through activation of the AMPK/p38 MAPK pathway. Therefore, sLPC is a candidate pharmacological agent for the treatment of bacterial infections in clinically relevant conditions. PMID:27517519

  17. GM1 induces p38 and microtubule dependent ramification of rat primary microglia in vitro.

    PubMed

    Park, Ji-Young; Kim, Hee Young; Jou, Ilo; Park, Sang Myun

    2008-12-01

    Microglia are immunologically competent cells in the central nervous system and considered to be a key player in brain inflammation. The morphological change of microglia has been shown to be linked to functional phenotypes both in vivo and in vitro. As an attempt to identify factors that regulate microglial morphology, we investigated the effect of gangliosides on microglial ramification in vitro. Brain gangliosides mixture and GM1 induced typical ramification of cultured rat primary microglia, however, GD1a and GT1b did not. Although GM1 significantly induced the expression of neurotrophin-3 (NT-3), NT-3 did not induce typical morphological changes in cultured rat primary microglia. SB203580 (an inhibitor of p38), and paclitaxel and nocodazole (microtubule-disrupting drugs) inhibited GM1-induced microglial ramification, but Jaki (an inhibitor of JAK), PD98059 (an inhibitor of Erk1/2), SP600125 (an inhibitor of JNK), and cytochalasin B and latrunculin B (actin polymerization inhibitors) did not, suggesting that GM1 induced ramification of microglia in p38- and microtubule-dependent manner. This in vitro system would be helpful in understanding the mechanisms of microglial ramification and physiological roles of gangliosides in microglia. PMID:18930716

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  20. Docosahexenoic acid treatment ameliorates cartilage degeneration via a p38 MAPK-dependent mechanism.

    PubMed

    Wang, Zhenzhong; Guo, Ai; Ma, Lifeng; Yu, Haomiao; Zhang, Liang; Meng, Hai; Cui, Yinpeng; Yu, Fei; Yang, Bo

    2016-06-01

    Osteoarthritis (OA) is a common chronic inflammatory disease, characterized by cartilage degradation. The aberrant expression of matrix metalloproteinase-13 (MMP-13) plays a vital role in the pathogenesis of OA. The anti‑inflammatory property of docosahexenoic acid (DHA) was previously revealed and showed that DHA retards the progress of many types of inflammatory disease. To evaluate the prophylactic function of DHA in OA, the effect of DHA on cartilage degeneration was assessed in interleukin‑1β (IL‑1β) stimulated human chondrosarcoma SW1353 cells or a rat model of adjuvant‑induced arthritis (AIA). The safe concentration range (0‑50 µg/ml in vitro) of DHA was determined by flow cytometry and MTT assay. The inhibitory effects of DHA on MMP‑13 mRNA and protein expression were confirmed by RT‑qPCR, ELISA and western blotting. Furthermore, findings of an in vivo study showed that DHA can increase the thickness of articular cartilage and decrease MMP‑13 expression in cartilage matrix in a rat AIA model. We also revealed the mechanism by which DHA ameliorates cartilage degeneration from OA. The DHA-mediated inhibition of MMP‑13 expression was partially attributed to the inactivation of the p38 mitogen‑activated protein kinases pathway by suppressing p‑p38 in IL-1β-stimulated SW1353 cells and a rat AIA model. Our findings suggested that DHA is a promising therapeutic agent that may be used for the prevention and treatment of OA. PMID:27082436

  1. Wip1 phosphatase positively modulates dendritic spine morphology and memory processes through the p38MAPK signaling pathway

    PubMed Central

    Fernandez, Francesca; Soon, Irene; Li, Zeng; Kuan, Tan Chee; Min, Deng Hong; Wong, Esther Sook-Miin; Demidov, Oleg N.; Paterson, Malcolm C.; Dawe, Gavin; Bulavin, Dmitry V.; Xiao, Zhi-Cheng

    2012-01-01

    Dendritic spine morphology is modulated by protein kinase p38, a mitogen-activated protein (MAPK), in the hippocampus. Protein p38MAPK is a substrate of wip1, a protein phosphatase. The role of wip1 in the central nervous system (CNS) has never been explored. Here, we report a novel function of wip1 in dendritic spine morphology and memory processes. Wip1 deficiency decreases dendritic spine size and density in pyramidal neurons of the hippocampal CA1 region. Simultaneously, impairments in object recognition tasks and contextual memory occur in wip1 deficient mice, but are reversed in wip1/p38 double mutant mice. Thus, our findings demonstrate that wip1 modulates dendritic morphology and memory processes through the p38MAPK signaling pathway. In addition to the well-characterized role of the wip1/p38MAPK in cell death and differentiation, we revealed the novel contribution of wip1 to cognition and dendritic spine morphology, which may suggest new approaches to treating neurodegenerative disorders. PMID:22983193

  2. Alisertib induces apoptosis and autophagy through targeting the AKT/mTOR/AMPK/p38 pathway in leukemic cells.

    PubMed

    Fu, Yunfeng; Zhang, Yanan; Gao, Meng; Quan, Lingli; Gui, Rong; Liu, Jing

    2016-07-01

    Alisertib, a potent and selective Aurora kinase A inhibitor, has been demonstrated to exert potent anti-cancer effects in pre-clinical and clinical studies. However, mechanisms of action of alisertib, including the molecular pathways involved in alisertib-induced apoptosis and autophagy of leukemic cells, have remained elusive. The aim of the present study was to investigate the effects of alisertib on cell growth, apoptosis and autophagy and to delineate the possible molecular mechanisms in leukemic cells. Acid phosphatase, MTT and Annexin V/propidium iodide staining assays as well as immunostaining for light chain 3B showed that treatment of the REH leukemia cell line with alisertib exerted potent growth inhibitory effects, and induced apoptosis and autophagy in a dose‑dependent manner. Western blot analysis indicated that these effects may be attributed to the suppression of the activity of the Akt/mammalian target of rapamycin/5'-AMP-dependent kinase/p38 mitogen-activated protein kinase signaling pathways in REH cells. The present study confirmed that alisertib may represent a promising autophagy-inducing drug for the treatment of leukemia and shed light on its molecular mechanism of action. PMID:27177156

  3. 13-acetoxysarcocrassolide induces apoptosis on human gastric carcinoma cells through mitochondria-related apoptotic pathways: p38/JNK activation and PI3K/AKT suppression.

    PubMed

    Su, Ching-Chyuan; Chen, Jeff Yi-Fu; Din, Zhong-Hao; Su, Jui-Hsin; Yang, Zih-Yan; Chen, Yi-Jen; Wang, Robert Y L; Wu, Yu-Jen

    2014-10-01

    13-acetoxysarcocrassolide (13-AC), an active compound isolated from cultured Formosa soft coral Sarcophyton crassocaule, was found to possess anti-proliferative and apoptosis-inducing activities against AGS (human gastric adenocarcinoma cells) gastric carcinoma cells. The anti-tumor effects of 13-AC were determined by MTT assay, colony formation assessment, cell wound-healing assay, TUNEL/4,6-Diamidino-2-phenylindole (DAPI) staining, Annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining and flow cytometry. 13-AC inhibited the growth and migration of gastric carcinoma cells in a dose-dependent manner and induced both early and late apoptosis as assessed by flow cytometer analysis. 13-AC-induced apoptosis was confirmed through observation of a change in ΔΨm, up-regulated expression levels of Bax and Bad proteins, down-regulated expression levels of Bcl-2, Bcl-xl and Mcl-1 proteins, and the activation of caspase-3, caspase-9, p38 and JNK. Furthermore, inhibition of p38 and JNK activity by pretreatment with SB03580 (a p38-specific inhibitor) and SP600125 (a JNK-specific inhibitor) led to rescue of the cell cytotoxicity of 13-AC-treated AGS cells, indicating that the p38 and the JNK pathways are also involved in the 13-AC-induced cell apoptosis. Together, these results suggest that 13-AC induces cell apoptosis against gastric cancer cells through triggering of the mitochondrial-dependent apoptotic pathway as well as activation of the p38 and JNK pathways. PMID:25342459

  4. Lidamycin induces marked G2 cell cycle arrest in human colon carcinoma HT-29 cells through activation of p38 MAPK pathway.

    PubMed

    Liu, Xia; Bian, Chunjing; Ren, Kaihuan; Jin, Haixia; Li, Baowei; Shao, Rong-Guang

    2007-03-01

    Lidamycin (LDM), a member of the enediyne antibiotic family, is presently undergoing phase I clinical trials in P.R. China. In this study, we investigated the mechanisms of LDM-induced cell cycle arrest in order to support its use in clinical cancer therapy. Using human colon carcinoma HT-29 cells, we observed that LDM induced G2 cell cycle arrest in a time- and dose-dependent manner. LDM-induced G2 arrest was associated with increasing phosphorylation of Chk1, Chk2, Cdc25C, Cdc2 and expression of Cdc2 and cyclin B1. In addition, cytoplasmic localization of cyclin B1 was also involved in LDM-induced G2 arrest. Moreover, we found that p38 MAPK pathway contributed to LDM-induced G2 arrest. Inhibition of p38 MAPK by its inhibitor SB203580 not only attenuated LDM-induced G2 arrest but also potentiated LDM-induced apoptosis, which was accompanied by decreasing phosphorylation of Cdc2 and increasing expression of FasL and phosphorylation of JNK. Finally, we demonstrated that cells at G1 phase were more sensitive to LDM. Together, our findings suggest that p38 MAPK signaling pathway is involved in LDM-induced G2 arrest, at least partly, and a combination of LDM with p38 MAPK inhibitor may represent a new strategy for human colon cancer therapy. PMID:17273739

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

    PubMed Central

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

    2007-01-01

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

  6. Induction of apoptosis by sinulariolide from soft coral through mitochondrial-related and p38MAPK pathways on human bladder carcinoma cells.

    PubMed

    Neoh, Choo-Aun; Wang, Robert Y-L; Din, Zhong-Hao; Su, Jui-Hsin; Chen, Yu-Kuei; Tsai, Feng-Jen; Weng, Shun-Hsiang; Wu, Yu-Jen

    2012-12-01

    Sinulariolide, an isolated compound from the soft coral Sinularia flexibilis, possesses the anti-proliferative, anti-migratory and apoptosis-inducing activities against the TSGH bladder carcinoma cell. The anti-tumor effects of sinulariolide were determined by 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, cell migration assay and flow cytometry, respectively. Sinulariolide inhibited the growth and migration of bladder carcinoma cells in a dose-dependent manner, as well as induced both early and late apoptosis as determined by the flow cytometer. Also, the sinulariolide-induced apoptosis is related to the mitochondrial-mediated apoptosis via caspase-dependent pathways, elucidated by the loss of mitochondrial membrane potential, release of cytochrome C, activation of caspase-3/-9, Bax and Bad, as well as suppression of Bcl-2/Bcl-xL/Mcl-1. Detection of the PARP-1 cleaved product suggested the partial involvement of caspase-independent pathways. Moreover, inhibition of p38MAPK activity leads to the rescue of the cell cytotoxicity of sinulariolide-treated TSGH cells, indicating that the p38MAPK pathway is also involved in the sinulariolide-induced cell apoptosis. Altogether, these results suggest that sinulariolide induces apoptosis against bladder cancer cells through mitochondrial-related and p38MAPK pathways. PMID:23249971

  7. Induction of Apoptosis by Sinulariolide from Soft Coral through Mitochondrial-Related and p38MAPK Pathways on Human Bladder Carcinoma Cells

    PubMed Central

    Neoh, Choo-Aun; Wang, Robert Y.-L.; Din, Zhong-Hao; Su, Jui-Hsin; Chen, Yu-Kuei; Tsai, Feng-Jen; Weng, Shun-Hsiang; Wu, Yu-Jen

    2012-01-01

    Sinulariolide, an isolated compound from the soft coral Sinularia flexibilis, possesses the anti-proliferative, anti-migratory and apoptosis-inducing activities against the TSGH bladder carcinoma cell. The anti-tumor effects of sinulariolide were determined by 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, cell migration assay and flow cytometry, respectively. Sinulariolide inhibited the growth and migration of bladder carcinoma cells in a dose-dependent manner, as well as induced both early and late apoptosis as determined by the flow cytometer. Also, the sinulariolide-induced apoptosis is related to the mitochondrial-mediated apoptosis via caspase-dependent pathways, elucidated by the loss of mitochondrial membrane potential, release of cytochrome C, activation of caspase-3/-9, Bax and Bad, as well as suppression of Bcl-2/Bcl-xL/Mcl-1. Detection of the PARP-1 cleaved product suggested the partial involvement of caspase-independent pathways. Moreover, inhibition of p38MAPK activity leads to the rescue of the cell cytotoxicity of sinulariolide-treated TSGH cells, indicating that the p38MAPK pathway is also involved in the sinulariolide-induced cell apoptosis. Altogether, these results suggest that sinulariolide induces apoptosis against bladder cancer cells through mitochondrial-related and p38MAPK pathways. PMID:23249971

  8. Selective inhibition of the p38 alternative activation pathway in infiltrating T cells inhibits pancreatic cancer progression.

    PubMed

    Alam, Muhammad S; Gaida, Matthias M; Bergmann, Frank; Lasitschka, Felix; Giese, Thomas; Giese, Nathalia A; Hackert, Thilo; Hinz, Ulf; Hussain, S Perwez; Kozlov, Serguei V; Ashwell, Jonathan D

    2015-11-01

    Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive neoplasm characterized by a marked fibro-inflammatory microenvironment, the presence of which can promote both cancer induction and growth. Therefore, selective manipulation of local cytokines is an attractive, although unrealized, therapeutic approach. T cells possess a unique mechanism of p38 mitogen-activated protein kinase (MAPK) activation downstream of T cell receptor (TCR) engagement through the phosphorylation of Tyr323 (pY323). This alternative p38 activation pathway is required for pro-inflammatory cytokine production. Here we show in human PDAC that a high percentage of infiltrating pY323(+) T cells was associated with large numbers of tumor necrosis factor (TNF)-α- and interleukin (IL)-17-producing CD4(+) tumor-infiltrating lymphocytes (TILs) and aggressive disease. The growth of mouse pancreatic tumors was inhibited by genetic ablation of the alternative p38 pathway, and transfer of wild-type CD4(+) T cells, but not those lacking the alternative pathway, enhanced tumor growth in T cell-deficient mice. Notably, a plasma membrane-permeable peptide derived from GADD45-α, the naturally occurring inhibitor of p38 pY323(+) (ref. 7), reduced CD4(+) TIL production of TNF-α, IL-17A, IL-10 and secondary cytokines, halted growth of implanted tumors and inhibited progression of spontaneous KRAS-driven adenocarcinoma in mice. Thus, TCR-mediated activation of CD4(+) TILs results in alternative p38 activation and production of protumorigenic factors and can be targeted for therapeutic benefit. PMID:26479921

  9. Selective inhibition of the p38 alternative activation pathway in infiltrating T cells inhibits pancreatic cancer progression

    PubMed Central

    Alam, Muhammad S.; Gaida, Matthias M.; Bergmann, Frank; Lasitschka, Felix; Giese, Thomas; Giese, Nathalia A.; Hackert, Thilo; Hinz, Ulf; Hussain, S. Perwez; Kozlov, Serguei V.; Ashwell, Jonathan D.

    2015-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive neoplasm characterized by a marked fibro-inflammatory microenvironment1, the presence of which can promote both cancer induction and growth2–4. Therefore, selective manipulation of local cytokines is an attractive if unrealized therapeutic approach. T cells possess a unique mechanism of activation of p38 MAPK downstream of T cell receptor (TCR) engagement by phosphorylation of Tyr-323 (pY323). This alternative p38 activation pathway is required for pro-inflammatory cytokine production5,6. Here we show in human PDAC that a high percentage of infiltrating pY323+ T cells was associated with large numbers of TNFα and IL-17-producing CD4+ tumor-infiltrating lymphocytes (TIL) and aggressive disease. The growth of murine pancreatic tumors was inhibited by genetic ablation of the alternative p38 pathway, and transfer of wild type CD4+ T cells but not those lacking the alternative pathway enhanced tumor growth in T cell-deficient mice. Strikingly, a plasma membrane-permeable peptide derived from Gadd45α, the naturally-occurring inhibitor of p38 pY323+ (ref. 7), reduced CD4+ TIL production of TNFα, IL-17A, IL-10, and secondary cytokines, halted growth of implanted tumors, and inhibited progression of spontaneous K-ras-driven adenocarcinoma in mice. Thus, TCR-mediated activation of CD4+ TIL results in alternative p38 activation and production of pro-tumorigenic factors, and can be targeted for therapeutic benefit. PMID:26479921

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  12. Sema4C participates in myogenic differentiation in vivo and in vitro through the p38 MAPK pathway.

    PubMed

    Wu, Haitao; Wang, Xuan; Liu, Shuhong; Wu, Yan; Zhao, Tong; Chen, Xiaoping; Zhu, Lingling; Wu, Yanrui; Ding, Xuefeng; Peng, Xiaozhong; Yuan, Jiangang; Wang, Xiaomin; Fan, Wenhong; Fan, Ming

    2007-06-01

    Sema4C is a member of transmembrane semaphorin proteins which regulate axonal guidance in the developing nervous system. The expression of Sema4C was dramatically induced not only during differentiation of C2C12 mouse myoblasts, but also during injury-induced skeletal muscle regeneration. C2C12 cells stably or transiently expressing Sema4C both showed increased myogenic differentiation reflected by accelerated myotube formation and expression of muscle-specific proteins. Overexpression of Sema4C elicited p38 phosphorylation directly, and the effects of Sema4C during myogenic differentiation could be abolished by the p38alpha-specific inhibitor SB203580. Knockdown of Sema4C by siRNA transfection during C2C12 myoblasts differentiation could suppress the phosphorylation of p38 followed by dramatically diminished myotube formation. Sema4C could activate the myogenin promoter during myogenic differentiation. This activation could be abolished by p38 inhibitor SB203580. Taken together, these observations reveal novel functional potentialities of Sema4C which suggest that Sema4C promotes terminal myogenic differentiation in a p38 MAPK-dependent manner. PMID:17498836

  13. [Regulative mechanism of renal inflammatory-related p38MAPK signaling pathway in diabetic nephropathy and interventional effects of Chinese herbal medicine].

    PubMed

    Chen, Hao-Li; Wan, Yi-Gang; Zhao, Qing; Huang, Yan-Ru; Shi, Xi-Miao; Meng, Xian-Jie; Yao, Jian

    2013-07-01

    It is reported, in the process of diabetic nephropathy (DN), inflammatory-related p38 mitogen-activated protein kinase (MAPK) signaling pathway has a close relationship with renal injury. On the one hand,many factors in the upstream including hyperglycemia, abnormal hemodynamics, oxidative stress, and pro-inflammatory cytokines could activate p38MAPK signaling pathway. On the other hand,the activated p38MAPK signaling pathway could lead to renal damage via activating inflammatory cells, inducing the expression of inflammatory mediators, and intervening cytokines production. CHM could intervene p38MAPK signaling pathway through multi-ways, including inhibiting inflammatory cytokines expression, regulating phosphorylated p38MAPK (p-p38MAPK) expression, and reducing fibrogenic factors expression. PMID:24199552

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

    PubMed

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

    2016-02-28

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

  15. Endothelial lipase is upregulated by interleukin-6 partly via the p38 MAPK and p65 NF-κB signaling pathways.

    PubMed

    Yue, Xin; Wu, Minghui; Jiang, Hong; Hao, Jing; Zhao, Qinghao; Zhu, Qing; Saren, Gaowa; Zhang, Yun; Zhang, Xiaoli

    2016-09-01

    To investigate the effects of inflammatory factor interleukin (IL)‑6 on the expression of endothelial lipase (EL) and its potential signaling pathways in atherosclerosis, a primary culture of human umbilical vein endothelial cells (HUVECs) was established and treated as follows: i) Control group without any treatment; ii) recombinant human (rh)IL‑6 treatment (10 ng/ml) for 0, 4, 8, 12 and 24 h; iii) p38 mitogen‑activated protein kinases (MAPKs) inhibitor (SB203580, 10 µmol/l) pretreatment for 1 h prior to rhIL‑6 (10 ng/ml) treatment; iv) nuclear factor (NF)‑κB activation inhibitor (pyrrolidine dithiocarbamate, 10 mmol/l) pretreatment for 1 h prior to rhIL‑6 (10 ng/ml) treatment. EL levels were detected by immunocytochemical staining and western blot analysis. Proliferation of HUVECs was detected by immunostaining of proliferating cell nuclear antigen (PCNA) and an MTT assay. p38 MAPK and NF‑κB p65 levels were detected by western blotting. The results showed that rhIL‑6 treatment increased EL expression and proliferation of HUVECs. NF‑κB p65 and MAPK p38 protein levels also increased in a time‑dependent manner in HUVECs after rhIL‑6 treatment. NF‑κB inhibitor and MAPK p38 inhibitor prevented the effects of rhIL‑6 on EL expression. In conclusion, inflammatory factor IL‑6 may participate in the pathogenesis of atherosclerosis by increasing EL expression and the proliferation of endothelial cells via the p38 MAPK and NF-κB signaling pathways. PMID:27430252

  16. Taurine prevents arsenic-induced cardiac oxidative stress and apoptotic damage: Role of NF-{kappa}B, p38 and JNK MAPK pathway

    SciTech Connect

    Ghosh, Jyotirmoy; Das, Joydeep; Manna, Prasenjit

    2009-10-01

    Cardiac dysfunction is a major cause of morbidity and mortality worldwide due to its complex pathogenesis. However, little is known about the mechanism of arsenic-induced cardiac abnormalities and the use of antioxidants as the possible protective agents in this pathophysiology. Conditionally essential amino acid, taurine, accounts for 25% to 50% of the amino acid pool in myocardium and possesses antioxidant properties. The present study has, therefore, been carried out to investigate the underlying mechanism of the beneficial role of taurine in arsenic-induced cardiac oxidative damage and cell death. Arsenic reduced cardiomyocyte viability, increased reactive oxygen species (ROS) production and intracellular calcium overload, and induced apoptotic cell death by mitochondrial dependent caspase-3 activation and poly-ADP ribose polymerase (PARP) cleavage. These changes due to arsenic exposure were found to be associated with increased IKK and NF-{kappa}B (p65) phosphorylation. Pre-exposure of myocytes to an IKK inhibitor (PS-1145) prevented As-induced caspase-3 and PARP cleavage. Arsenic also markedly increased the activity of p38 and JNK MAPKs, but not ERK to that extent. Pre-treatment with SP600125 (JNK inhibitor) and SB203580 (p38 MAPK inhibitor) attenuated NF-{kappa}B and IKK phosphorylation indicating that p38 and JNK MAPKs are mainly involved in arsenic-induced NF-{kappa}B activation. Taurine treatment suppressed these apoptotic actions, suggesting that its protective role in arsenic-induced cardiomyocyte apoptosis is mediated by attenuation of p38 and JNK MAPK signaling pathways. Similarly, arsenic intoxication altered a number of biomarkers related to cardiac oxidative stress and other apoptotic indices in vivo and taurine supplementation could reduce it. Results suggest that taurine prevented arsenic-induced myocardial pathophysiology, attenuated NF-{kappa}B activation via IKK, p38 and JNK MAPK signaling pathways and could possibly provide a protection

  17. Induction of COX-2 protein expression by vanadate in A549 human lung carcinoma cell line through EGF receptor and p38 MAPK-mediated pathway

    SciTech Connect

    Chien, P.-S.; Mak, O.-T.; Huang, H.-J. . E-mail: haojen@mail.ncku.edu.tw

    2006-01-13

    Vanadate is a transition metal widely distributed in the environment. It has been reported that vanadate associated with air pollution particles can modify DNA synthesis, causing cell growth arrest, and apoptosis. Moreover, vanadium exposure was also found to cause the synthesis of inflammatory cytokines, such as interleukin-1, tumor necrosis factor-{alpha}, and prostaglandin E{sub 2}. Here, we found that exposure of A549 human lung carcinoma cells to vanadate led to extracellular signal-regulated kinase, c-Jun NH{sub 2}-terminal protein kinases (JNKs), p38 mitogen-activated protein kinase (p38) activation, and COX-2 protein expression in a dose-dependent manner. SB203580, a p38 MAPK inhibitor, but not PD098059 and SP600125, specific inhibitor of MKK1 and selective inhibitor of JNK, respectively, suppressed COX-2 expression. Furthermore, the epithelial growth factor (EGF) receptor specific inhibitor (PD153035) reduced vanadate-induced COX-2 expression. However, scavenging of vanadate-induced reactive oxygen species by catalase, a specific H{sub 2}O{sub 2} inhibitor, or DPI, an NADPH oxidase inhibitor, resulted in no inhibition on COX-2 expression. Together, we suggested that EGF receptor and p38 MAPK signaling pathway may be involved in vanadate-induced COX-2 protein expression in A549 human lung carcinoma cell line.

  18. OPN Induces FoxM1 Expression and Localization through ERK 1/2, AKT, and p38 Signaling Pathway in HEC-1A Cells

    PubMed Central

    Xie, Yunpeng; Li, Yinghua; Kong, Ying

    2014-01-01

    Mammalian embryo implantation is an extremely complex process and requires endometrial receptivity. In order to establish this receptivity, sequential proliferation and differentiation during the menstrual cycle is necessary. Forkhead box M1 (FoxM1) is described as a major oncogenic transcription factor in tumor initiation, promotion and progression. According to these functions, we believe that FoxM1 should also play an essential role in embryo implantation. Osteopontin (OPN), an adhesion molecule, has been studied extensively in reproduction. In this study, we observed the expression and distribution of FoxM1 during the proliferative-phase and secretory-phase human endometrium and the pre-implantation mouse uterus firstly. Then we observed the relationship between OPN and FoxM1. Our results showed that FoxM1 was mainly distributed in glandular epithelium. OPN increased the expression of FoxM1 in the human uterine epithelial cell line HEC-1A cells in a time- and concentration-dependent manner. OPN regulates FoxM1 to influence HEC-1A cell proliferation through extracellular regulated protein kinases (ERK 1/2), protein kinase B (PKB, AKT), and the p38 mitogen activated protein kinases (p38MAPK, p38) signaling pathway. Inhibition of ERK 1/2, AKT and p38 suppressed OPN-induced FoxM1 expression and location. Our data indicate that FoxM1 might be regulated by OPN to influence endometrial proliferation to establish endometrial receptivity. PMID:25522167

  19. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces microglial nitric oxide production and subsequent rat primary cortical neuron apoptosis through p38/JNK MAPK pathway.

    PubMed

    Li, Yuanye; Chen, Gang; Zhao, Jianya; Nie, Xiaoke; Wan, Chunhua; Liu, Jiao; Duan, Zhiqing; Xu, Guangfei

    2013-10-01

    It has been widely accepted that microglia, which are the innate immune cells in the brain, upon activation can cause neuronal damage. In the present study, we investigated the role of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in regulating microglial nitric oxide production and its role in causing neuronal damage. The study revealed that TCDD stimulates the expression of inducible nitric oxide synthase (iNOS) as well as the production of nitric oxide (NO) in a dose- and time-dependent manner. Further, a rapid activation of p38 and JNK MAPKs was found in HAPI microglia following TCDD treatment. Blockage of p38 and JNK kinases with their specific inhibitors, SB202190 and SP600125, significantly reduced TCDD-induced iNOS expression and NO production. In addition, it was demonstrated through treating rat primary cortical neurons with media conditioned with TCDD treated microglia that microglial iNOS activation mediates neuronal apoptosis. Lastly, it was also found that p38 and JNK MAPK inhibitors could attenuate the apoptosis of rat cortical neurons upon exposure to medium conditioned by TCDD-treated HAPI microglial cells. Based on these observations, we highlight that the p38/JNK MAPK pathways play an important role in TCDD-induced iNOS activation in rat HAPI microglia and in the subsequent induction of apoptosis in primary cortical neurons. PMID:23969120

  20. OPN induces FoxM1 expression and localization through ERK 1/2, AKT, and p38 signaling pathway in HEC-1A cells.

    PubMed

    Xie, Yunpeng; Li, Yinghua; Kong, Ying

    2014-01-01

    Mammalian embryo implantation is an extremely complex process and requires endometrial receptivity. In order to establish this receptivity, sequential proliferation and differentiation during the menstrual cycle is necessary. Forkhead box M1 (FoxM1) is described as a major oncogenic transcription factor in tumor initiation, promotion and progression. According to these functions, we believe that FoxM1 should also play an essential role in embryo implantation. Osteopontin (OPN), an adhesion molecule, has been studied extensively in reproduction. In this study, we observed the expression and distribution of FoxM1 during the proliferative-phase and secretory-phase human endometrium and the pre-implantation mouse uterus firstly. Then we observed the relationship between OPN and FoxM1. Our results showed that FoxM1 was mainly distributed in glandular epithelium. OPN increased the expression of FoxM1 in the human uterine epithelial cell line HEC-1A cells in a time- and concentration-dependent manner. OPN regulates FoxM1 to influence HEC-1A cell proliferation through extracellular regulated protein kinases (ERK 1/2), protein kinase B (PKB, AKT), and the p38 mitogen activated protein kinases (p38MAPK, p38) signaling pathway. Inhibition of ERK 1/2, AKT and p38 suppressed OPN-induced FoxM1 expression and location. Our data indicate that FoxM1 might be regulated by OPN to influence endometrial proliferation to establish endometrial receptivity. PMID:25522167

  1. The Role of JNK and p38 MAPK Activities in UVA-Induced Signaling Pathways Leading to AP-1 Activation and c-Fos Expression1

    PubMed Central

    Silvers, Amy L; Bachelor, Michael A; Bowden, G Timothy

    2003-01-01

    Abstract To further delineate ultraviolet A (UVA) signaling pathways in the human keratinocyte cell line HaCaT, we examined the potential role of mitogen-activated protein kinases (MAPKs) in UVA-induced activator protein-1 (AP-1) transactivation and c-Fos expression. UVA-induced phosphorylation of p38 and c-Jun N-terminal kinase (JNK) proteins was detected immediately after irradiation and disappeared after approximately 2 hours. Conversely, phosphorylation of extracellular signal-regulated kinase was significantly inhibited for up to 1 hour post-UVA irradiation. To examine the role of p38 and JNK MAPKs in UVA-induced AP-1 and c-fos transactivations, the selective pharmacologic MAPK inhibitors, SB202190 (p38 inhibitor) and SP600125 (JNK inhibitor), were used to independently treat stably transfected HaCaT cells in luciferase reporter assays. Both SB202190 and SP600125 dose-dependently inhibited UVA-induced AP-1 and c-fos transactivations. SB202190 (0.25–0.5 µM) and SP600125 (62–125 nM) treatments also primarily inhibited UVA-induced c-Fos expression. These results demonstrated that activation of both JNK and p38 play critical role in UVA-mediated AP-1 transactivation and c-Fos expression in these human keratinocyte cells. Targeted inhibition of these MAPKs with their selective pharmacologic inhibitors may be effective chemopreventive strategies for UVA-induced nonmelanoma skin cancer. PMID:14511403

  2. Regulation of gene expression by the small GTPase Rho through the ERK6 (p38γ) MAP kinase pathway

    PubMed Central

    Marinissen, Maria Julia; Chiariello, Mario; Gutkind, J. Silvio

    2001-01-01

    Small GTP-binding proteins of the Rho-family, Rho, Rac, and Cdc42, have been traditionally linked to the regulation of the cellular actin-based cytoskeleton. Rac and Cdc42 can also control the activity of JNK, thus acting in a molecular pathway transmitting extracellular signals to the nucleus. Interestingly, Rho can also regulate gene expression, albeit by a not fully understood mechanism. Here, we found that activated RhoA can stimulate c-jun expression and the activity of the c-jun promoter. As the complexity of the signaling pathways controlling the expression of c-jun has begun to be unraveled, this finding provided a unique opportunity to elucidate the biochemical routes whereby RhoA regulates nuclear events. We found that RhoA can initiate a linear kinase cascade leading to the activation of ERK6 (p38γ), a recently identified member of the p38 family of MAPKs. Furthermore, we present evidence that RhoA, PKN, MKK3/MKK6, and ERK6 (p38γ) are components of a novel signal transduction pathway involved in the regulation of gene expression and cellular transformation. PMID:11238375

  3. 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

  4. MLK-3 activates the SAPK/JNK and p38/RK pathways via SEK1 and MKK3/6.

    PubMed Central

    Tibbles, L A; Ing, Y L; Kiefer, F; Chan, J; Iscove, N; Woodgett, J R; Lassam, N J

    1996-01-01

    Mixed lineage kinase-3 (MLK-3) is a 97 kDa serine/threonine kinase with multiple interaction domains, including a Cdc42 binding motif, but unknown function. Cdc42 and the related small GTP binding protein Rac1 can activate the SAPK/JNK and p38/RK stress-responsive kinase cascades, suggesting that MLK-3 may have a role in upstream regulation of these pathways. In support of this role, we demonstrate that MLK-3 can specifically activate the SAPK/JNK and p38/RK pathways, but has no effect on the activation of ERKs. Immunoprecipitated MLK-3 catalyzed the phosphorylation of SEK1 in vitro, and co-transfected MLK-3 induced phosphorylation of SEK1 and MKK3 at sites required for activation, suggesting direct regulation of these protein kinases. Furthermore, interactions between MLK-3 and SEK and MLK-3 and MKK6 were observed in co-precipitation experiments. Finally, kinase-dead mutants of MLK-3 blocked activation of the SAPK pathway by a newly identified mammalian analog of Ste20, germinal center kinase, but not by MEKK, suggesting that MLK-3 functions to activate the SAPK/JNK and p38/RK cascades in response to stimuli transduced by Ste20-like kinases. Images PMID:9003778

  5. Natural Hirudin Increases Rat Flap Viability by Anti-Inflammation via PARs/p38/NF-κB Pathway

    PubMed Central

    Peng, Liu; Pan, Xinyuan; Yin, Guoqian

    2015-01-01

    The present study aimed to evaluate the effect of natural hirudin on rat random skin flap viability and to determine the mechanism. Forty-eight rats were randomly divided into 2 groups. After the dorsal skin flap operation (3 cm × 10 cm in size), subcutaneous injections of 6 ATU hirudin were administered to group H (n = 24) every 12 h, while group C (n = 24) received an equal volume of 0.9% normal saline. Six rats from each group were euthanized 1, 2, 4, and 7 days after the operation. A full skin sample was collected from these rats to measure the p38-mitogen-activated protein kinase (p38-MAPK), phospho-p38- (Pp38-) MAPK, nuclear factor-κB (NF-κB) p65, phosphor-NF-κB (pNF-κB) p65, tumour necrosis factor- (TNF-) α, interleukin- (IL-) 6, and intercellular adhesion molecule- (ICAM-) 1 levels via western blot (WB) assays. The results showed that flap viability was significantly higher in the hirudin-treated group, which showed a reduced inflammatory response compared with the control group. The Pp38/p38, pNF-κB p65/NF-κB p65, TNF-α, IL-6, and ICAM-1 levels in the hirudin-treated group were lower than those in the control group. The results demonstrated that hirudin could improve random skin flap viability and suggested that this effect maybe occurs by blocking the thrombin/proteinase-activated receptors (PARs)/p38/NF-κB signalling pathway, thus decreasing the inflammatory response. PMID:26770977

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

    PubMed Central

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

    2016-01-01

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

  7. The p38-MK2-HuR pathway potentiates EGFRvIII-IL-1β-driven IL-6 secretion in glioblastoma cells.

    PubMed

    Gurgis, F M S; Yeung, Y T; Tang, M X M; Heng, B; Buckland, M; Ammit, A J; Haapasalo, J; Haapasalo, H; Guillemin, G J; Grewal, T; Munoz, L

    2015-05-28

    The microenvironment of glioblastoma (GBM) contains high levels of inflammatory cytokine interleukin 6 (IL-6), which contributes to promote tumour progression and invasion. The common epidermal growth factor receptor variant III (EGFRvIII) mutation in GBM is associated with significantly higher levels of IL-6. Furthermore, elevated IL-1β levels in GBM tumours are also believed to activate GBM cells and enhance IL-6 production. However, the crosstalk between these intrinsic and extrinsic factors within the oncogene-microenvironment of GBM causing overproduction of IL-6 is poorly understood. Here, we show that EGFRvIII potentiates IL-1β-induced IL-6 secretion from GBM cells. Importantly, exacerbation of IL-6 production is most effectively attenuated in EGFRvIII-expressing GBM cells with inhibitors of p38 mitogen-activated protein kinase (p38 MAPK) and MAPK-activated protein kinase 2 (MK2). Enhanced IL-6 production and increased sensitivity toward pharmacological p38 MAPK and MK2 inhibitors in EGFRvIII-expressing GBM cells is associated with increased MK2-dependent nuclear-cytoplasmic shuttling and accumulation of human antigen R (HuR), an IL-6 mRNA-stabilising protein, in the cytosol. IL-1β-stimulated activation of the p38 MAPK-MK2-HuR pathway significantly enhances IL-6 mRNA stability in GBM cells carrying EGFRvIII. Further supporting a role for the p38 MAPK-MK2-HuR pathway in the development of inflammatory environment in GBM, activated MK2 is found in more than 50% of investigated GBM tissues and correlates with lower grade and secondary GBMs. Taken together, p38 MAPK-MK2-HuR signalling may enhance the potential of intrinsic (EGFRvIII) and extrinsic (IL-1β) factors to develop an inflammatory GBM environment. Hence, further improvement of brain-permeable and anti-inflammatory inhibitors targeting p38 MAPK, MK2 and HuR may combat progression of lower grade gliomas into aggressive GBMs. PMID:25088200

  8. Transcriptional signature of epidermal keratinocytes subjected to in vitro scratch wounding reveals selective roles for ERK1/2, p38, and phosphatidylinositol 3-kinase signaling pathways.

    PubMed

    Fitsialos, Giorgos; Chassot, Anne-Amandine; Turchi, Laurent; Dayem, Manal A; LeBrigand, Kevin; Moreilhon, Chimène; Meneguzzi, Guerrino; Buscà, Roser; Mari, Bernard; Barbry, Pascal; Ponzio, Gilles

    2007-05-18

    Covering denuded dermal surfaces after injury requires migration, proliferation, and differentiation of skin keratinocytes. To clarify the major traits controlling these intermingled biological events, we surveyed the genomic modifications occurring during the course of a scratch wound closure of cultured human keratinocytes. Using a DNA microarray approach, we report the identification of 161 new markers of epidermal repair. Expression data, combined with functional analysis performed with specific inhibitors of ERK, p38(MAPK) and phosphatidylinositol 3-kinase (PI3K), demonstrate that kinase pathways exert very selective functions by precisely controlling the expression of specific genes. Inhibition of the ERK pathway totally blocks the wound closure and inactivates many early transcription factors and EGF-type growth factors. p38(MAPK) inhibition only delays "healing," probably in line with the control of genes involved in the propagation of injury-initiated signaling. In contrast, PI3K inhibition accelerates the scratch closure and potentiates the scratch-dependent stimulation of three genes related to epithelial cell transformation, namely HAS3, HBEGF, and ETS1. Our results define in vitro human keratinocyte wound closure as a repair process resulting from a fine balance between positive signals controlled by ERK and p38(MAPK) and negative ones triggered by PI3K. The perturbation of any of these pathways might lead to dysfunction in the healing process, similar to those observed in pathological wounding phenotypes, such as hypertrophic scars or keloids. PMID:17363378

  9. Paeoniflorin attenuates ultraviolet B-induced apoptosis in human keratinocytes by inhibiting the ROS-p38-p53 pathway.

    PubMed

    Kong, Lingwen; Wang, Shangshang; Wu, Xiao; Zuo, Fuguo; Qin, Haihong; Wu, Jinfeng

    2016-04-01

    Ultraviolet (UV) light is one of the most harmful environmental factors that contribute to skin damage. Exposure to UV induces extensive generation of reactive oxygen species (ROS), and results in photoaging and skin cancer development. One approach to protecting human skin against UV radiation is the use of antioxidants. In recent years, naturally occurring herbal compounds have gained considerable attention as protective agents for UV exposure. Paeoniflorin (PF) is a novel natural antioxidant, which is isolated from peony root (Radix Paeoniae Alba). The present study evaluated the protective effects of PF on UV‑induced skin damage in vitro, and demonstrated that the effects were mediated via the ROS‑p38‑p53 pathway. The results of the present study demonstrated that treatment with PF (25, 50, and 100 µM) significantly increased the percentage of viable keratinocytes after UV‑B exposure. In addition, cell death analysis indicated that PF treatment markedly reduced UV‑B‑radiation‑induced apoptosis in keratinocytes, which was accompanied by increased procaspase 3 expression and decreased cleaved caspase 3 expression. Treatment with PF markedly reduced the production of ROS, and inhibited the activation of p38 and p53 in human keratinocytes, thus suggesting that the ROS‑p38‑p53 pathway has a role in UV‑B‑induced skin damage. In conclusion, the present study reported that PF was able to attenuate UV‑B‑induced cell damage in human keratinocytes. Notably, these effects were shown to be mediated, at least in part, via inhibition of the ROS-p38-p53 pathway. PMID:26936104

  10. Fenofibrate reduces cisplatin-induced apoptosis of renal proximal tubular cells via inhibition of JNK and p38 pathways.

    PubMed

    Thongnuanjan, Penjai; Soodvilai, Sirima; Chatsudthipong, Varanuj; Soodvilai, Sunhapas

    2016-01-01

    Cisplatin is widely used as a standard chemotherapy for solid tumors. The major adverse effect of cisplatin is nephrotoxicity in proximal tubular cells, via oxidative stress, DNA damage, cell apoptosis, and inflammation. The aim of this study was to investigate the pharmacological effect and mechanism of fibrate drugs on cisplatin-induced renal proximal tubular cell death. Cisplatin decreased cell viability of LLC-PK1 and HK-2 cells in a dose-dependent manner. Cisplatin-induced apoptosis was attenuated by co-treatment with fenofibrate while less so with clofibrate and bezafibrate. Fenofibrate's protective effect was not complimented by co-treatment with GW6471, a PPARα antagonist, indicating the protective effect occurred via a PPARα-independent mechanism. Treating cells with cisplatin induced reactive oxygen species (ROS), c-JUN N-terminal kinase (JNK), and p38 kinase (p38), but not extracellular signal-regulated kinase (ERK). Fenofibrate reversed cisplatin-induced JNK and p38 activation, but had no effect on ROS production. The findings suggest fenofibrate's protective effect on cisplatin-induced cytotoxicity is mediated by inhibition of JNK and p38. Moreover, fenofibrate did not alter cisplatin's antitumor effect on cancer cell lines including T84, SW-480, HepG2, and SK-LU-1 cells. Therefore, fenofibrate may be a candidate agent for further development as an adjuvant to cisplatin treatment. PMID:27193727

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

    PubMed

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

    2006-12-31

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

  12. Anthocyanins protected hearts against ischemic injury by reducing MMP-2 activity via Akt/P38 pathways

    PubMed Central

    Hao, Jie; Du, Hong; Li, Weiwei; Liu, Fan; Lu, Jingchao; Yang, Xiuchun; Cui, Wei

    2016-01-01

    Growing evidences suggest that there are close associations between anthocyanins and cardiac protection. However, little is known about the detailed roles of anthocyanins in regulating extracellular matrix (ECM) remodeling. Incubation of primary cultured fibroblasts with anthocyanins reduced both intracellular collagen expression and extracellular collagen secretion. Down-regulation of collagen production was also shown in infarcted cardiac tissues after permanent coronary artery ligation in mice treated with anthocyanins. The phosphorylation levels of Akt and/or P-38 were significantly increased by anthocyanins supplementation in primary cultured fibroblasts. Gelatin zymography analysis of matrix metalloproteinase-2 (MMP-2) activity in conditioned medium collected from fibroblasts demonstrated that anthocyanins treatment significantly reduced MMP-2 activity. These results demonstrated that anthocyanins play a role in mediating myocardial ECM remodeling and that the Akt/P-38 pathways mediate these protective effects on hearts. PMID:27158396

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

    SciTech Connect

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

    2013-11-15

    Stress-inducible protein heme oxygenase-1(HO-1) is well-appreciative to counteract oxidative damage and inflammatory stress involving the pathogenesis of alcoholic liver diseases (ALD). The potential role and signaling pathways of HO-1 metabolite carbon monoxide (CO), however, still remained unclear. To explore the precise mechanisms, ethanol-dosed adult male Balb/c mice (5.0 g/kg.bw.) or ethanol-incubated primary rat hepatocytes (100 mmol/L) were pretreated by tricarbonyldichlororuthenium (II) dimmer (CORM-2, 8 mg/kg for mice or 20 μmol/L for hepatocytes), as well as other pharmacological reagents. Our data showed that CO released from HO-1 induction by quercetin prevented ethanol-derived oxidative injury, which was abolished by CO scavenger hemoglobin. The protection was mimicked by CORM-2 with the attenuation of GSH depletion, SOD inactivation, MDA overproduction, and the leakage of AST, ALT or LDH in serum and culture medium induced by ethanol. Moreover, CORM-2 injection or incubation stimulated p38 phosphorylation and suppressed abnormal Tnfa and IL-6, accompanying the alleviation of redox imbalance induced by ethanol and aggravated by inflammatory factors. The protective role of CORM-2 was abolished by SB203580 (p38 inhibitor) but not by PD98059 (ERK inhibitor) or SP600125 (JNK inhibitor). Thus, HO-1 released CO prevented ethanol-elicited hepatic oxidative damage and inflammatory stress through activating p38 MAPK pathway, suggesting a potential therapeutic role of gaseous signal molecule on ALD induced by naturally occurring phytochemicals. - Highlights: • CO alleviated ethanol-derived liver oxidative and inflammatory stress in mice. • CO eased ethanol and inflammatory factor-induced oxidative damage in hepatocytes. • The p38 MAPK is a key signaling mechanism for the protective function of CO in ALD.

  14. Cross talk between cAMP and p38 MAPK pathways in the induction of leptin by hCG in human placental syncytiotrophoblasts.

    PubMed

    Ge, Y C; Li, J N; Ni, X T; Guo, C M; Wang, W S; Duan, T; Sun, K

    2011-08-01

    Leptin produced by the placental syncytiotrophoblasts participates in a number of processes in pregnancy including implantation, proliferation of the cytotrophoblasts, and nutrient transfer across the placenta. Despite the functional significance of leptin in pregnancy, the regulation of leptin synthesis is poorly understood in human placental syncytiotrophoblasts. In this study, we investigated the role of endogenous human chorionic gonadotropin (hCG) in the regulation of leptin production as well as the underlying mechanism involving the cross talk between cAMP and p38 mitogen-activated protein kinase (MAPK) pathways. We found that neutralization of endogenous hCG with its antibody dose dependently decreased leptin mRNA level and secretion, whereas exogenous hCG increased leptin mRNA level and secretion. Activation of the cAMP pathway with dibutyryl cAMP (db cAMP) or forskolin recapitulated the stimulatory effect of hCG on leptin expression. Inhibition of protein kinase A with H89 not only reduced the basal leptin expression but also attenuated the induced leptin expression by hCG. Treatment of the syncytiotrophoblasts with db cAMP and hCG phosphorylated p38 MAPK. Inhibition of p38 MAPK with SB203580 not only reduced the basal leptin production but also attenuated the leptin-induced production by both hCG and db cAMP. These data suggest that endogenous hCG plays a significant role in maintaining leptin production in human placental syncytiotrophoblasts, and this effect involves a cross talk between cAMP and p38 MAPK pathways. PMID:21562093

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

    PubMed Central

    Li, Xuefeng; Xie, Qing; Wu, Min

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  17. Interaction between ROS dependent DNA damage, mitochondria and p38 MAPK underlies senescence of human adult stem cells

    PubMed Central

    Borodkina, Aleksandra; Shatrova, Alla; Abushik, Polina; Nikolsky, Nikolay; Burova, Elena

    2014-01-01

    Human endometrium-derived mesenchymal stem cells (hMESCs) enter the premature senescence under sublethal oxidative stress, however underlying mechanism remains unknown. Here, we showed that exogenous H2O2 induces a rapid phosphorylation and co-localization of ATM, H2A.X, 53BP1 leading to DNA damage response (DDR) activation. DDR was accompanied with nuclear translocation of p-p53 followed by up-regulation of p21Waf1 and the permanent hypophosphorylation of pRb. Additionally, the increased p38MAPK/MAPKAPK-2 activation persisted in H2O2-treated cells. We suggest that both p53/p21/pRb and p38MAPK/MAPKAPK-2 pathways are responsible for establishing an irreversible cell cycle arrest that is typical of senescence. The process of further stabilization of senescence required prolonged DDR signaling activation that was provided by the permanent ROS production which in turn was regulated by both p38MAPK and the increased functional mitochondria. To reverse senescence, the pharmacological inhibition of p38MAPK was performed. Cell treatment with SB203580 was sufficient to recover partially senescence phenotype, to block the ROS elevation, to decrease the mitochondrial function, and finally to rescue proliferation. Thus, suppression of the p38MAPK pathway resulted in a partial prevention of H2O2-induced senescence of hMESCs. The current study is the first to reveal the molecular mechanism of the premature senescence of hMESCs in response to oxidative stress. PMID:24934860

  18. Interaction between ROS dependent DNA damage, mitochondria and p38 MAPK underlies senescence of human adult stem cells.

    PubMed

    Borodkina, Aleksandra; Shatrova, Alla; Abushik, Polina; Nikolsky, Nikolay; Burova, Elena

    2014-06-01

    Human endometrium-derived mesenchymal stem cells (hMESCs) enter the premature senescence under sublethal oxidative stress, however underlying mechanism remains unknown. Here, we showed that exogenous H2O2 induces a rapid phosphorylation and co-localization of ATM, H2A.X, 53BP1 leading to DNA damage response (DDR) activation. DDR was accompanied with nuclear translocation of p-p53 followed by up-regulation of p21Waf1 and the permanent hypophosphorylation of pRb. Additionally, the increased p38MAPK/MAPKAPK-2 activation persisted in H2O2-treated cells. We suggest that both p53/p21/pRb and p38MAPK/MAPKAPK-2 pathways are responsible for establishing an irreversible cell cycle arrest that is typical of senescence. The process of further stabilization of senescence required prolonged DDR signaling activation that was provided by the permanent ROS production which in turn was regulated by both p38MAPK and the increased functional mitochondria. To reverse senescence, the pharmacological inhibition of p38MAPK was performed. Cell treatment with SB203580 was sufficient to recover partially senescence phenotype, to block the ROS elevation, to decrease the mitochondrial function, and finally to rescue proliferation. Thus, suppression of the p38MAPK pathway resulted in a partial prevention of H2O2-induced senescence of hMESCs. The current study is the first to reveal the molecular mechanism of the premature senescence of hMESCs in response to oxidative stress. PMID:24934860

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

    PubMed Central

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

    2015-01-01

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

  20. Glabridin Mediate Caspases Activation and Induces Apoptosis through JNK1/2 and p38 MAPK Pathway in Human Promyelocytic Leukemia Cells

    PubMed Central

    Chien, Ming-Hsien; Chen, Hui-Yu; Yang, Shun-Fa; Hsiao, Pei-Ching

    2014-01-01

    Background Glabridin, a prenylated isoflavonoid of G. glabra L. roots, has been associated with a wide range of biological properties such as regulation of energy metabolism, estrogenic, neuroprotective, anti-osteoporotic, and skin-whitening in previous studies. However, the effect of glabridin on tumor cells metastasis has not been clearly clarified. Here, the molecular mechanism by which glabridin anticancer effects in human promyelocytic leukemia cells was investigated. Methodology and Principal Findings The results showed that glabridin significantly inhibited cell proliferation of four AML cell lines (HL-60, MV4-11, U937, and THP-1). Furthermore, glabridin induced apoptosis of HL-60 cells through caspases-3, -8, and -9 activations and PARP cleavage in dose- and time-dependent manner. Moreover, western blot analysis also showed that glabridin increase phosphorylation of ERK1/2, p38 MAPK and JNK1/2 in dose- and time-dependent manner. Inhibition of p38 MAPK and JNK1/2 by specific inhibitors significantly abolished the glabridin-induced activation of the caspase-3, -8 and -9. Conclusion Taken together, our results suggest that glabridin induced HL-60 cell apoptosis through p38 MAPK and JNK1/2 pathways and could serve as a potential additional chemotherapeutic agent for treating AML. PMID:24901249

  1. Phloretin induces apoptosis of non-small cell lung carcinoma A549 cells via JNK1/2 and p38 MAPK pathways

    PubMed Central

    MIN, JIE; LI, XU; HUANG, KENAN; TANG, HUA; DING, XINYU; QI, CHEN; QIN, XIONG; XU, ZHIFEI

    2015-01-01

    Phloretin (Ph) existing in apples, pears and various vegetables is known to have antitumor activities in several cancer cell lines. However, little is known about its effect on human lung cancer cells. The aim of the present study was to see whether Ph could induce apoptosis of non-small cell lung cancer (NSCLC) cells, and explore the possible underlying mechanism of action. We found that Ph markedly induced cell apoptosis of NSCLC cell line A549, and inhibited the migration of A549 cells in a dose-dependent manner. The expression level of BAX, cleaved caspase-3 and -9, and degraded form of PARP was increased and Bcl-2 was decreased after Ph treatment. In addition, the phosphorylation of P38 MAPK, ERK1/2 and JNK1/2 was increased in a dose-dependent manner in parallel with Ph treatment. Inhibition of P38 MAPK and JNK1/2 by specific inhibitors significantly abolished the Ph-induced activation of the caspase-3 and -9. In vivo tumor-suppression assay further indicated that Ph (20 mg/kg) displayed a more significant inhibitory effect on A549 xenografts in tumor growth. All these findings indicate that Ph is able to inhibit NSCLC A549 cell growth by inducing apoptosis through P38 MAPK and JNK1/2 pathways, and therefore may prove to be an adjuvant to the treatment of NSCLC. PMID:26503828

  2. Gastrointestinal Congestion Dilates the Hepatic Artery Through the P38 MAPK Signal Transduction Pathway During Liver Transplantation.

    PubMed

    Cao, Zhongping; Tang, Xiaowen; Hou, Shike

    2016-01-01

    During the neohepatic stage of liver transplantation, hemodynamics change markedly. The current study aimed to investigate whether gastrointestinal congestion caused by inferior vena cava and hepatic portal vein clamping can dilate the hepatic artery and to determine the associated mechanisms. Ring segments of the hepatic artery were treated with the plasma from gastrointestinal congestion or the superior vena cava. The fractions in gastrointestinal congestion and the superior vena cava plasma were tested, and the effect of these fractions on the tone of the hepatic artery ring was examined. Different signal transduction blockers and different inhibitors were then used to determine the exact signal transduction pathway involved. In addition, endothelial cell structure was observed by transmission electron microscopy after treatment with the gastrointestinal congestion plasma or the superior vena cava plasma. Gastrointestinal congestion plasma contained more inflammatory cytokines than superior vena cava plasma, and these cytokines could cause hepatic artery ring dilatation. A P38 mitogen-activated protein kinase (P38 MAPK) signal transduction pathway blocker and nitric oxide (NO), prostaglandin (PGI2), nuclear factor-κB (NF-κB), and adenosine triphosphate (ATP)-sensitive K (KATP) channel inhibitors were able to significantly reverse the ring tension caused by gastrointestinal congestion plasma. The normal endothelium was also injured by treatment with gastrointestinal congestion plasma. The inflammatory cytokines in gastrointestinal congestion can cause hepatic artery ring dilatation through the P38 MAPK signal transduction pathway, and this phenomenon is also associated with NO, PGI2, NF-κB, and the KATP channel. These inflammatory cytokines can injure endothelial cells in the hepatic artery. PMID:26955003

  3. Zinc deficiency exacerbates while zinc supplement attenuates cardiac hypertrophy in high-fat diet-induced obese mice through modulating p38 MAPK-dependent signaling.

    PubMed

    Wang, Shudong; Luo, Manyu; Zhang, Zhiguo; Gu, Junlian; Chen, Jing; Payne, Kristen McClung; Tan, Yi; Wang, Yuehui; Yin, Xia; Zhang, Xiang; Liu, Gilbert C; Wintergerst, Kupper; Liu, Quan; Zheng, Yang; Cai, Lu

    2016-09-01

    Childhood obesity often leads to cardiovascular diseases, such as obesity-related cardiac hypertrophy (ORCH), in adulthood, due to chronic cardiac inflammation. Zinc is structurally and functionally essential for many transcription factors; however, its role in ORCH and underlying mechanism(s) remain unclear and were explored here in mice with obesity induced with high-fat diet (HFD). Four week old mice were fed on either HFD (60%kcal fat) or normal diet (ND, 10% kcal fat) for 3 or 6 months, respectively. Either diet contained one of three different zinc quantities: deficiency (ZD, 10mg zinc per 4057kcal), normal (ZN, 30mg zinc per 4057kcal) or supplement (ZS, 90mg zinc per 4057kcal). HFD induced a time-dependent obesity and ORCH, which was accompanied by increased cardiac inflammation and p38 MAPK activation. These effects were worsened by ZD in HFD/ZD mice and attenuated by ZS in HFD/ZS group, respectively. Also, administration of a p38 MAPK specific inhibitor in HFD mice for 3 months did not affect HFD-induced obesity, but completely abolished HFD-induced, and zinc deficiency-worsened, ORCH and cardiac inflammation. In vitro exposure of adult cardiomyocytes to palmitate induced cell hypertrophy accompanied by increased p38 MAPK activation, which was heightened by zinc depletion with its chelator TPEN. Inhibition of p38 MAPK with its specific siRNA also prevented the effects of palmitate on cardiomyocytes. These findings demonstrate that ZS alleviates but ZD heightens cardiac hypertrophy in HFD-induced obese mice through suppressing p38 MAPK-dependent cardiac inflammatory and hypertrophic pathways. PMID:27346292

  4. p38 MAP kinase regulates circadian rhythms in Drosophila.

    PubMed

    Vrailas-Mortimer, Alysia D; Ryan, Sarah M; Avey, Matthew J; Mortimer, Nathan T; Dowse, Harold; Sanyal, Subhabrata

    2014-12-01

    The large repertoire of circadian rhythms in diverse organisms depends on oscillating central clock genes, input pathways for entrainment, and output pathways for controlling rhythmic behaviors. Stress-activated p38 MAP Kinases (p38K), although sparsely investigated in this context, show circadian rhythmicity in mammalian brains and are considered part of the circadian output machinery in Neurospora. We find that Drosophila p38Kb is expressed in clock neurons, and mutants in p38Kb either are arrhythmic or have a longer free-running periodicity, especially as they age. Paradoxically, similar phenotypes are observed through either transgenic inhibition or activation of p38Kb in clock neurons, suggesting a requirement for optimal p38Kb function for normal free-running circadian rhythms. We also find that p38Kb genetically interacts with multiple downstream targets to regulate circadian locomotor rhythms. More specifically, p38Kb interacts with the period gene to regulate period length and the strength of rhythmicity. In addition, we show that p38Kb suppresses the arrhythmic behavior associated with inhibition of a second p38Kb target, the transcription factor Mef2. Finally, we find that manipulating p38K signaling in free-running conditions alters the expression of another downstream target, MNK/Lk6, which has been shown to cycle with the clock and to play a role in regulating circadian rhythms. These data suggest that p38Kb may affect circadian locomotor rhythms through the regulation of multiple downstream pathways. PMID:25403440

  5. IL-1{beta} promotes neurite outgrowth by deactivating RhoA via p38 MAPK pathway

    SciTech Connect

    Temporin, Ko; Tanaka, Hiroyuki Kuroda, Yusuke; Okada, Kiyoshi; Yachi, Koji; Moritomo, Hisao; Murase, Tsuyoshi; Yoshikawa, Hideki

    2008-01-11

    Expression of the pro-inflammatory cytokine interleukin-1 beta (IL-1{beta}) is increased following the nervous system injury. Generally IL-1{beta} induces inflammation, leading to neural degeneration, while several neuropoietic effects have also been reported. Although neurite outgrowth is an important step in nerve regeneration, whether IL-1{beta} takes advantages on it is unclear. Now we examine how it affects neurite outgrowth. Following sciatic nerve injury, expression of IL-1{beta} is increased in Schwann cells around the site of injury, peaking 1 day after injury. In dorsal root ganglion (DRG) neurons and cerebellar granule neurons (CGNs), neurite outgrowth is inhibited by the addition of myelin-associated glycoprotein (MAG), activating RhoA. IL-1{beta} overcomes MAG-induced neurite outgrowth inhibition, by deactivating RhoA. Intracellular signaling experiments reveal that p38 MAPK, and not nuclear factor-kappa B (NF-{kappa}B), mediated this effect. These findings suggest that IL-1{beta} may contribute to nerve regeneration by promoting neurite outgrowth following nerve injury.

  6. Simvastatin induces differentiation of rabbit articular chondrocytes via the ERK-1/2 and p38 kinase pathways.

    PubMed

    Han, Yohan; Kim, Song Ja

    2016-08-15

    Statins are competitive inhibitors of hydroxy-methyl-glutaryl Coenzyme A (HMG-CoA) reductase, a key enzyme involved in the conversion of HMG-CoA to the cholesterol precursor mevalonate. Some statins, such as simvastatin (simvastatin), have been shown to have anti-cancer and anti-inflammatory effects, reducing cartilage degradation in osteoarthritic rabbits in vivo. However, the regulatory mechanisms undergirding simvastatin mediated chondrocyte differentiation have not been well elucidated. Thus, we investigated the action and mechanism of simvastatin on differentiation of rabbit articular chondrocytes through western blot analyses, RT-PCR, and immunohistochemical (IHC) and immunofluorescence (IF) staining. Simvastatin treatment was found to induce type II collagen expression and sulfated-proteoglycan synthesis in a dose- and time-dependent manner. Indeed, RT-PCR revealed increased expression of type II collagen on treatment with simvastatin. Both IHC and IF staining indicated differentiation of chondrocytes. Simvastatin treatment reduced activation of ERK-1/2 and stimulated activation of p38 kinase. Inhibition of ERK-1/2 with PD98059 enhanced simvastatin induced differentiation, whereas inhibition of p38 kinase with SB203580 inhibited simvastatin induced differentiation. Simvastatin treatment also inhibits loss of type II collagen in serial monolayer culture. Collectively, our results indicate that ERK-1/2 and p38 kinase regulate simvastatin-induced differentiation of chondrocytes in opposing manners. Thus, these findings suggest that simvastatin may be a potential therapeutic drug for osteoarthritis. PMID:27475840

  7. Quercetin attenuates cardiomyocyte apoptosis via inhibition of JNK and p38 mitogen-activated protein kinase signaling pathways.

    PubMed

    Li, Chengqiu; Wang, Ting; Zhang, Chunyuan; Xuan, Jichang; Su, Changjiang; Wang, Yuqi

    2016-02-15

    Quercetin (Que), a plant-derived flavonoid, possesses various biological functions. Moreover, Que exerts multiple beneficial actions in treatment of cardiovascular diseases and there are an inverse association between Que intakes and occurrence and development of various cardiovascular diseases. Some researchers have inferred that the mechanisms of Que to protect cardiomyocytes from ischemia/reperfusion (I/R) injury may be involved in modulation of intracellular signal pathways and regulation of proteins expression in vivo. The current study investigated whether Que has any protective effects on cardiomyocytes from hypoxia/reoxygenation (H/R) in vitro and its potential cardioprotective mechanisms. The cell viability of Que on H9c2 cardiomyoblast cells was assessed by MTT. Apoptosis was evaluated by both Hoechst33342 staining and Flow cytometric analysis (FACS). Furthermore, the effect of Que, SP600125 (JNK inhibitor) and SB203580 (p38 inhibitor) on mitogen-activated protein kinases (MAPKs) and the expression of apoptosis related proteins (Bcl-2, Bax and caspase-3) was determined by Western blotting. MTT assays showed that pretreatment with Que could increase the viability of H9c2 cardiomyocytes that suffered H/R. Both Hoechst33342 staining and FACS confirmed that Que could remarkably suppress the H/R-induced apoptotic cardiomyocytes. In addition, Que significantly alleviated H/R-induced the phosphorylation of JNK and p38, which further increased Bcl-2 expression and inhibited the activation of Bax and caspase-3 directly or indirectly. In summary, our results imply that Que can induce cardioprotection by inhibition of JNK and p38 mitogen-activated protein kinase signaling pathways and modulate the expression of Bcl-2 and Bax proteins that provides a new experimental foundation for myocardial ischemia disease therapy. PMID:26680104

  8. Intervention of electroacupuncture on spinal p38 MAPK/ATF-2/VR-1 pathway in treating inflammatory pain induced by CFA in rats

    PubMed Central

    2013-01-01

    Background Previous studies have demonstrated that p38 MAPK signal transduction pathway plays an important role in the development and maintenance of inflammatory pain. Electroacupuncture (EA) can suppress the inflammatory pain. However, the relationship between EA effect and p38 MAPK signal transduction pathway in inflammatory pain remains poorly understood. It is our hypothesis that p38 MAPK/ATF-2/VR-1 and/or p38 MAPK/ATF-2/COX-2 signal transduction pathway should be activated by inflammatory pain in CFA-injected model. Meanwhile, EA may inhibit the activation of p38 MAPK signal transduction pathway. The present study aims to investigate that anti-inflammatory and analgesic effect of EA and its intervention on the p38 MAPK signal transduction pathway in a rat model of inflammatory pain. Results EA had a pronounced anti-inflammatory and analgesic effect on CFA-induced chronic inflammatory pain in rats. EA could quickly raise CFA-rat’s paw withdrawal thresholds (PWTs) and maintain good and long analgesic effect, while it subdued the ankle swelling of CFA rats only at postinjection day 14. EA could down-regulate the protein expressions of p-p38 MAPK and p-ATF-2, reduced the numbers of p-p38 MAPK-IR cells and p-ATF-2-IR cells in spinal dorsal horn in CFA rats, inhibited the expressions of both protein and mRNA of VR-1, but had no effect on the COX-2 mRNA expression. Conclusions The present study indicates that inhibiting the activation of spinal p38 MAPK/ATF-2/VR-1 pathway may be one of the main mechanisms via central signal transduction pathway in the process of anti-inflammatory pain by EA in CFA rats. PMID:23517865

  9. Isoegomaketone Upregulates Heme Oxygenase-1 in RAW264.7 Cells via ROS/p38 MAPK/Nrf2 Pathway.

    PubMed

    Jin, Chang Hyun; So, Yang Kang; Han, Sung Nim; Kim, Jin-Baek

    2016-09-01

    Isoegomaketone (IK) was isolated from Perilla frutescens, which has been widely used as a food in Asian cuisine, and evaluated for its biological activity. We have already confirmed that IK induced the HO-1 expression via Nrf2 activation in RAW264.7 cells. In this study, we investigated the effect of IK on the mechanism of HO-1 expression. IK upregulated HO-1 mRNA and protein expression in a dose dependent manner. The level of HO-1 mRNA peaked at 4 h after 15 μM IK treatment. To investigate the mechanisms of HO-1 expression modulation by IK, we used pharmacological inhibitors for the protein kinase C (PKC) family, PI3K, and p38 MAPK. IK-induced HO-1 mRNA expression was only suppressed by SB203580, a specific inhibitor of p38 MAPK. ROS scavengers (N-acetyl-L-cysteine, NAC, and glutathione, GSH) also blocked the IK-induced ROS production and HO-1 expression. Furthermore, both NAC and SB203580 suppressed the IK-induced Nrf2 activation. In addition, ROS scavengers suppressed other oxidative enzymes such as catalase (CAT), glutathione S-transferase (GST), and NADH quinone oxidoreductase (NQO-1) in IK-treated RAW264.7 cells. Taken together, it can be concluded that IK induced the HO-1 expression through the ROS/p38 MAPK/ Nrf2 pathway in RAW264.7 cells. PMID:27582555

  10. Isoegomaketone Upregulates Heme Oxygenase-1 in RAW264.7 Cells via ROS/p38 MAPK/Nrf2 Pathway

    PubMed Central

    Jin, Chang Hyun; So, Yang Kang; Han, Sung Nim; Kim, Jin-Baek

    2016-01-01

    Isoegomaketone (IK) was isolated from Perilla frutescens, which has been widely used as a food in Asian cuisine, and evaluated for its biological activity. We have already confirmed that IK induced the HO-1 expression via Nrf2 activation in RAW264.7 cells. In this study, we investigated the effect of IK on the mechanism of HO-1 expression. IK upregulated HO-1 mRNA and protein expression in a dose dependent manner. The level of HO-1 mRNA peaked at 4 h after 15 μM IK treatment. To investigate the mechanisms of HO-1 expression modulation by IK, we used pharmacological inhibitors for the protein kinase C (PKC) family, PI3K, and p38 MAPK. IK-induced HO-1 mRNA expression was only suppressed by SB203580, a specific inhibitor of p38 MAPK. ROS scavengers (N-acetyl-L-cysteine, NAC, and glutathione, GSH) also blocked the IK-induced ROS production and HO-1 expression. Furthermore, both NAC and SB203580 suppressed the IK-induced Nrf2 activation. In addition, ROS scavengers suppressed other oxidative enzymes such as catalase (CAT), glutathione S-transferase (GST), and NADH quinone oxidoreductase (NQO-1) in IK-treated RAW264.7 cells. Taken together, it can be concluded that IK induced the HO-1 expression through the ROS/p38 MAPK/ Nrf2 pathway in RAW264.7 cells. PMID:27582555

  11. Isoalantolactone inhibits the migration and invasion of human breast cancer MDA-MB-231 cells via suppression of the p38 MAPK/NF-κB signaling pathway.

    PubMed

    Wang, Jing; Cui, Li; Feng, Liang; Zhang, Zhenhai; Song, Jie; Liu, Dan; Jia, Xiaobin

    2016-09-01

    Isoalantolactone is a bioactive sesquiterpene lactone isolated from the flowering plant Inula helenium L. This study was conducted to assess the anti-migratory and anti-invasive activities of isoalantolactone in MDA-MB-231 cells, and to explore the underlying mechanisms. Wound-healing and Transwell chambers assays demonstrated that isoalantolactone inhibited the adhesion, migration and invasion of MDA-MB-231 cells. The activity and expression of MMP-2 and MMP-9 were downregulated by isoalantolactone in a dose-dependent manner. Additionally, isoalantolactone markedly decreased the p-p38 MAPK level, whereas no significant change in p-ERK1/2 and p-JNK1/2 was noted. The downregulation of MMP-2 and MMP-9 protein expression and suppression of in vitro invasion might be associated with the blockade of p38 MAPK activation. Furthermore, isoalantolactone blocked the translocation of NF-κB p65 from the cytoplasm into the nucleus. These results revealed that isoalantolactone inhibited the adhesion, migration and invasion of MDA-MB-231 cells via suppression of the p38 MAPK/NF-κB signaling pathway, and isoalantolactone might be an alternative treatment for breast cancer. PMID:27461575

  12. Involvement of PI3K/Akt, ERK and p38 signaling pathways in emodin-mediated extrinsic and intrinsic human hepatoblastoma cell apoptosis.

    PubMed

    Cui, Yuting; Lu, Peiran; Song, Ge; Liu, Qian; Zhu, Di; Liu, Xuebo

    2016-06-01

    As a natural anthraquinone derivative, 1,3,8-trihydroxy-6-methylanthraquinone, known as emodin, has recently been reported to possess potential chemopreventive capacity, but the underlying molecular mechanism of its hepatocyte toxicity remains poorly clarified. The present research indicated that emodin targeted HepG2 cells without being cytotoxic to primary human hepatocyte cells in comparison with chrysophanol and rhein. The anti-proliferative effect of emodin was ascribed to occurrence of apoptosis, which characterized by higher ethidium bromide signal, brighter DAPI fluorescence, cleavages of procaspase-3 and poly (ADP-ribose) polymerase as well as quantitative result from Annexin V-FITC/PI double staining. Furthermore, emodin improved Bax/Bcl-2 ratio, elicited disruption of mitochondrial membrane potential and promoted efflux of cytochrome c to cytosol, indicative of features of mitochondria-dependent apoptotic signals. Emodin concurrently led to activations of Fas, Fas-L, caspase-8 and tBid, which provoked death receptor apoptotic signals. Notably, activated tBid relayed the Fas apoptotic signal to the mitochondrial pathway. Besides, emodin effectively attenuated phosphorylations of Akt and ERK and promoted phosphorylation of p38. Inhibitions of PI3K/Akt and ERK and activation of p38 mediated emodin-induced apoptosis through modulating the mitochondrial pathway and/or death receptor pathway. Additionally, there was a cross-talk between PI3K/Akt and MAPKs pathways in emodin-induced apoptosis. PMID:27032576

  13. A Novel p38 Mitogen-activated Protein Kinase/Elk-1 Transcription Factor-dependent Molecular Mechanism Underlying Abnormal Endothelial Cell Proliferation in Plexogenic Pulmonary Arterial Hypertension*

    PubMed Central

    Patel, Monal; Predescu, Dan; Tandon, Rajive; Bardita, Cristina; Pogoriler, Jennifer; Bhorade, Sangeeta; Wang, Minhua; Comhair, Suzy; Ryan-Hemnes, Anna; Chen, Jiwang; Machado, Roberto; Husain, Aliya; Erzurum, Serpil; Predescu, Sanda

    2013-01-01

    Plexiform lesions (PLs), the hallmark of plexogenic pulmonary arterial hypertension (PAH), contain phenotypically altered, proliferative endothelial cells (ECs). The molecular mechanism that contributes to EC proliferation and formation of PLs is poorly understood. We now show that a decrease in intersectin-1s (ITSN-1s) expression due to granzyme B (GrB) cleavage during inflammation associated with PAH and the high p38/Erk1/2MAPK activity ratio caused by the GrB/ITSN cleavage products lead to EC proliferation and selection of a proliferative/plexiform EC phenotype. We used human pulmonary artery ECs of PAH subjects (ECPAH), paraffin-embedded and frozen human lung tissue, and animal models of PAH in conjunction with microscopy imaging, biochemical, and molecular biology approaches to demonstrate that GrB cleaves ITSN-1s, a prosurvival protein of lung ECs, and generates two biologically active fragments, an N-terminal fragment (GrB-EHITSN) with EC proliferative potential and a C-terminal product with dominant negative effects on Ras/Erk1/2. The proliferative potential of GrB-EHITSN is mediated via sustained phosphorylation of p38MAPK and Elk-1 transcription factor and abolished by chemical inhibition of p38MAPK. Moreover, lung tissue of PAH animal models and human specimens and ECPAH express lower levels of ITSN-1s compared with controls and the GrB-EHITSN cleavage product. Moreover, GrB immunoreactivity is associated with PLs in PAH lungs. The concurrent expression of the two cleavage products results in a high p38/Erk1/2MAPK activity ratio, which is critical for EC proliferation. Our findings identify a novel GrB-EHITSN-dependent pathogenic p38MAPK/Elk-1 signaling pathway involved in the poorly understood process of PL formation in severe PAH. PMID:23893408

  14. A novel p38 mitogen-activated protein kinase/Elk-1 transcription factor-dependent molecular mechanism underlying abnormal endothelial cell proliferation in plexogenic pulmonary arterial hypertension.

    PubMed

    Patel, Monal; Predescu, Dan; Tandon, Rajive; Bardita, Cristina; Pogoriler, Jennifer; Bhorade, Sangeeta; Wang, Minhua; Comhair, Suzy; Hemnes, Anna Ryan; Ryan-Hemnes, Anna; Chen, Jiwang; Machado, Roberto; Husain, Aliya; Erzurum, Serpil; Predescu, Sanda

    2013-09-01

    Plexiform lesions (PLs), the hallmark of plexogenic pulmonary arterial hypertension (PAH), contain phenotypically altered, proliferative endothelial cells (ECs). The molecular mechanism that contributes to EC proliferation and formation of PLs is poorly understood. We now show that a decrease in intersectin-1s (ITSN-1s) expression due to granzyme B (GrB) cleavage during inflammation associated with PAH and the high p38/Erk1/2(MAPK) activity ratio caused by the GrB/ITSN cleavage products lead to EC proliferation and selection of a proliferative/plexiform EC phenotype. We used human pulmonary artery ECs of PAH subjects (EC(PAH)), paraffin-embedded and frozen human lung tissue, and animal models of PAH in conjunction with microscopy imaging, biochemical, and molecular biology approaches to demonstrate that GrB cleaves ITSN-1s, a prosurvival protein of lung ECs, and generates two biologically active fragments, an N-terminal fragment (GrB-EH(ITSN)) with EC proliferative potential and a C-terminal product with dominant negative effects on Ras/Erk1/2. The proliferative potential of GrB-EH(ITSN) is mediated via sustained phosphorylation of p38(MAPK) and Elk-1 transcription factor and abolished by chemical inhibition of p38(MAPK). Moreover, lung tissue of PAH animal models and human specimens and EC(PAH) express lower levels of ITSN-1s compared with controls and the GrB-EH(ITSN) cleavage product. Moreover, GrB immunoreactivity is associated with PLs in PAH lungs. The concurrent expression of the two cleavage products results in a high p38/Erk1/2(MAPK) activity ratio, which is critical for EC proliferation. Our findings identify a novel GrB-EH(ITSN)-dependent pathogenic p38(MAPK)/Elk-1 signaling pathway involved in the poorly understood process of PL formation in severe PAH. PMID:23893408

  15. Melatonin promotes osteoblast differentiation and mineralization of MC3T3-E1 cells under hypoxic conditions through activation of PKD/p38 pathways.

    PubMed

    Son, Jang-Ho; Cho, Yeong-Cheol; Sung, Iel-Yong; Kim, In-Ryoung; Park, Bong-Soo; Kim, Yong-Deok

    2014-11-01

    Osteoblastic differentiation and bone-forming capacity are known to be suppressed under hypoxic conditions. Melatonin has been shown to influence cell differentiation. A number of in vitro and in vivo studies have suggested that melatonin also has an anabolic effect on bone, by promoting osteoblastic differentiation. However, the precise mechanisms and the signaling pathways involved in this process, particularly under hypoxic conditions, are unknown. This study investigated whether melatonin could promote osteoblastic differentiation and mineralization of preosteoblastic MC3T3-E1 cells under hypoxic conditions. Additionally, we examined the molecular signaling pathways by which melatonin mediates this process. We found that melatonin is capable of promoting differentiation and mineralization of MC3T3-E1 cells cultured under hypoxic conditions. Melatonin upregulated ALP activity and mRNA levels of Alp, Osx, Col1, and Ocn in a time- and concentration-dependent manner. Alizarin red S staining showed that the mineralized matrix in hypoxic MC3T3-E1 cells formed in a manner that was dependent on melatonin concentration. Moreover, melatonin stimulated phosphorylation of p38 Mapk and Prkd1 in these MC3T3-E1 cells. We concluded that melatonin promotes osteoblastic differentiation of MC3T3-E1 cells under hypoxic conditions via the p38 Mapk and Prkd1 signaling pathways. PMID:25250639

  16. Macrophage-derived BAFF induces AID expression through the p38MAPK/CREB and JNK/AP-1 pathways.

    PubMed

    Kim, Hyun-A; Seo, Goo-Young; Kim, Pyeung-Hyeun

    2011-03-01

    BAFF is expressed primarily by macrophages and DCs. BAFF stimulates the differentiation and survival of B cells and induces Ig production. We have demonstrated previously that murine macrophages treated with TGF-β1 or IFN-γ express membrane-bound and soluble forms of BAFF. The ability of these two forms of BAFF to induce expression of AID, which plays a critical role in Ig CSR in B cells, was investigated. Both forms of BAFF, derived from macrophages activated by IFN-γ or TGF-β1, can increase AID expression. Subsequent analysis of BAFF signaling suggested that BAFF induces AID through BCMA, a BAFF-receptor, and p38MAPK and CREB act as intermediates in AID expression. In addition, JNK and AP-1 have similar activities. Our findings suggest that macrophage-derived BAFF stimulates B cells to express AID through BCMA and at least two different pathways, including the p38MAPK/CREB and the JNK/AP-1 pathways. PMID:21169521

  17. Cinobufagin induces autophagy-mediated cell death in human osteosarcoma U2OS cells through the ROS/JNK/p38 signaling pathway

    PubMed Central

    MA, KUN; ZHANG, CHUAN; HUANG, MAN-YU; LI, WU-YIN; HU, GUO-QIANG

    2016-01-01

    The main objective of this study was to explore whether autophagy could be triggered by cinobufagin, and to clarify the role of autophagy in the antitumor effects of cinobufagin on U2OS cells and the underlying mechanisms. U2OS cells were exposed to 15, 30, 60 and 120 mg/l cinobufagin for 0, 12, 24 and 48 h. An MTT assay was used to measure cell viability. FITC-Annexin V/PI staining and flow cytometry were used to analyze the apoptotic ratio, while apoptotic morphological changes were assessed by PI and Hoechst 33258 viable cell staining. The effects of autophagy on the cells were investigated with GFP-LC3b green fluorescence plasmid transfection and transmission electron microscopy. The levels of caspase-3, -8, - 9, cleaved PARP, LC3-II/LC3-I, p62 and the activation of JNK/p-38 were detected by western blot analysis. Reactive oxygen species (ROS) fluorescence intensity was examined under fluorescence microscopy with an analysis software system. Cell proliferation was obviously inhibited by cinobufagin in a dose- and time-dependent manner. The apoptosis ratio was gradually increased with treatment time as evidenced by flow cytometric analysis and Hoechst 33258 staining. Exposure to cinobufagin resulted in the activation of caspase-3, -8, -9, as well as cleaved PARP which indicated that cinobufagin induced caspase-dependent apoptosis. Autophagy was confirmed in the cinobufagin-treated cells as evidenced by formation of autophagosomes, accumulation of GFP-LC3 fluorescence particles as well as the upregulation of LC3-II/LC3-I levels. Inhibition of autophagy diminished apoptosis as detected by the MTT assays. Moreover the percentage of apoptotic cells decreased following pretreatment with 3-MA, CQ and si-beclin-1. Cinobufagin also induced phosphorylation of the JNK and p38 signaling pathway as well as ROS generation. The JNK and p38 inhibitors significantly attenuated coexistence of apoptosis and autophagy-related proteins. The ROS scavenger also prevented

  18. Cinobufagin induces autophagy-mediated cell death in human osteosarcoma U2OS cells through the ROS/JNK/p38 signaling pathway.

    PubMed

    Ma, Kun; Zhang, Chuan; Huang, Man-Yu; Li, Wu-Yin; Hu, Guo-Qiang

    2016-07-01

    The main objective of this study was to explore whether autophagy could be triggered by cinobufagin, and to clarify the role of autophagy in the antitumor effects of cinobufagin on U2OS cells and the underlying mechanisms. U2OS cells were exposed to 15, 30, 60 and 120 mg/l cinobufagin for 0, 12, 24 and 48 h. An MTT assay was used to measure cell viability. FITC-Annexin Ⅴ/PI staining and flow cytometry were used to analyze the apoptotic ratio, while apoptotic morphological changes were assessed by PI and Hoechst 33258 viable cell staining. The effects of autophagy on the cells were investigated with GFP-LC3b green fluorescence plasmid transfection and transmission electron microscopy. The levels of caspase-3, -8, - 9, cleaved PARP, LC3-II/LC3-I, p62 and the activation of JNK/p-38 were detected by western blot analysis. Reactive oxygen species (ROS) fluorescence intensity was examined under fluorescence microscopy with an analysis software system. Cell proliferation was obviously inhibited by cinobufagin in a dose- and time-dependent manner. The apoptosis ratio was gradually increased with treatment time as evidenced by flow cytometric analysis and Hoechst 33258 staining. Exposure to cinobufagin resulted in the activation of caspase-3, -8, -9, as well as cleaved PARP which indicated that cinobufagin induced caspase-dependent apoptosis. Autophagy was confirmed in the cinobufagin-treated cells as evidenced by formation of autophagosomes, accumulation of GFP-LC3 fluorescence particles as well as the upregulation of LC3-II/LC3-I levels. Inhibition of autophagy diminished apoptosis as detected by the MTT assays. Moreover the percentage of apoptotic cells decreased following pretreatment with 3-MA, CQ and si-beclin-1. Cinobufagin also induced phosphorylation of the JNK and p38 signaling pathway as well as ROS generation. The JNK and p38 inhibitors significantly attenuated coexistence of apoptosis and autophagy-related proteins. The ROS scavenger also prevented

  19. Atorvastatin attenuates homocysteine-induced migration of smooth muscle cells through mevalonate pathway involving reactive oxygen species and p38 MAPK.

    PubMed

    Bao, Xiao-mei; Zheng, Hongchao

    2015-08-01

    Statins have been reported to have an antioxidant effect against homocysteine (Hcy)-induced endothelial dysfunction. It is unknown whether they have the same effect against migration of vascular smooth muscle cells (VSMCs) induced by Hcy. In this study, it was investigated whether and how atorvastatin could inhibit the Hcy-induced migration in cultured VSMCs and revealed the possible redox mechanism. VSMCs were isolated from the thoracic aortas of Sprague-Dawley rats. The migration of VSMCs was examined using a transwell technique and cell viability was determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide (MTT) assay. Reactive oxygen species (ROS) were measured using the fluoroprobe 2'7'-dichlorodihydrofluorescein diacetate. The activity of NADPH oxidase was assessed by lucigenin enhanced chemiluminescence. Expressions of Nox1 mRNA and p-p38MAPK protein were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. The results showed that atorvastatin inhibited the migration of VSMCs induced by Hcy, which was reversed by the mevalonate. In addition, pretreatment with the NADPH oxidase inhibitor DPI, the free radical scavenger NAC and the p38 MAPK inhibitor SB203580 blocked Hcy-induced VSMCs migration. Furthermore, atorvastatin suppressed Hcy-induced activation of NADPH oxidase and ROS, attenuated Hcy-induced overexpression of Nox1mRNA. Similar effects occurred with VSMCs transfected with Nox1 siRNA. Moreover, atorvastatin other than DPI, NAC, SB203580 and Nox1 siRNA transfection blocked Hcy-induced p38 MAPK phosphorylation, which was also reversed by the mevalonate. The data demonstrates that atorvastatin inhibits Hcy-induced VSMCs migration in a mevalonate pathway. Furthermore, a part of the biological effect of atorvastatin involves a decrease in the levels of Nox1-dependent ROS generation and p38 MAPK activation. PMID:26041506

  20. 15d-PGJ{sub 2} stimulates HO-1 expression through p38 MAP kinase and Nrf-2 pathway in rat vascular smooth muscle cells

    SciTech Connect

    Lim, Hyun-Joung; Lee, Kuy-Sook; Lee, Seahyoung; Park, Jin-Hee; Choi, Hye-Eun; Go, Sang Hee; Kwak, Hyun-Jeong; Park, Hyun-Young

    2007-08-15

    15d-PGJ{sub 2}, a potent endogenous ligand for peroxisome proliferators activated receptor-{gamma}, is a cyclopentenone-type prostaglandin produced by many different types of cells. Pertinent to its effect on vascular smooth muscle cell (VSMC), antiproliferative effects have been most frequently reported. In the present study, we investigated the effect of 15d-PGJ{sub 2} on HO-1 expression that has been reported to inhibit VSMC proliferation. According to our data, 15d-PGJ{sub 2} significantly induced ROS/NO production and HO-1 expression in rVSMCs. We also observed 15d-PGJ{sub 2}-induced translocation of Nrf-2. In addition, ROS scavenger pretreatment suppressed 15d-PGJ{sub 2}-induced HO-1 expression while PPAR{gamma} antagonist did not, suggesting nuclear translocation of Nrf-2 and subsequent HO-1 expression was ROS dependent rather than PPAR{gamma} dependent. Furthermore, an inhibitor of p38 MAPK abolished 15d-PGJ{sub 2}-induced HO-1 expression. These data suggest that 15d-PGJ{sub 2}-induced up-regulation of HO-1 is independent of PPAR{gamma} but dependent of ROS and p38 MAPK pathway. The present study reports for the first time that 15d-PGJ{sub 2} induces HO-1 expression possibly using Nrf-2 pathway as a response to ROS in VSMCs.

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

    PubMed

    Shu, Chengjie; Sun, Lingmei; Zhang, Weiming

    2016-08-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  4. Daidzein attenuates abdominal aortic aneurysm through NF-κB, p38MAPK and TGF-β1 pathways.

    PubMed

    Liu, Yan-Feng; Bai, Yun-Qing; Qi, Ming

    2016-07-01

    The current study focuses on the protection of daidzein on nerves, as daidzein was demonstrated to have a protective effect on neurons of the central nervous system in a glutamate excitotoxicity and oxygen/glucose deprivation model. However, the effect of daidzein on the abdominal aortic aneurysm (AAA) remains unclear. The angiotensin II-induced AAA mouse model was utilized in the present study to determine the effect of daidzein on AAA. The results demonstrated that daidzein significantly attenuated incidence of AAA, max aortic aneurysm and mortality in the angiotensin II‑induced AAA mice. Daidzein had an anti‑inflammatory effect by inhibiting tumor necrosis factor α (TNF-α), interleukin 1β (IL‑1β) and nuclear factor κB (NF‑κB) protein expression. In addition, daidzein strongly suppressed the gene expression of cyclooxygenase (COX)‑2, matrix metalloproteinase 2 (MMP‑2), tissue inhibitor of metalloproteinase 1 (TIMP-1), transforming growth factor β1 (TGF‑β1), and inhibited inducible nitric oxide synthase (iNOS) protein expression in angiotensin II‑induced AAA mice. It also inhibited phosphorylation of the p38 mitogen-activated protein kinase (MAPK) signaling pathway. These results demonstrate, to the best of our knowledge for the first time, that the anti‑inflammatory effects and inhibitory mechanism of daidzein attenuates AAA in angiotensin II‑induced mice. Daidzein contains strong anti‑inflammatory activity and affects various mechanism pathways including the NF‑κB, p38MAPK and TGF-β1 pathway. PMID:27222119

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  7. Discovery of biaryl-4-carbonitriles as antihyperglycemic agents that may act through AMPK-p38 MAPK pathway.

    PubMed

    Goel, Atul; Nag, Pankaj; Rahuja, Neha; Srivastava, Rohit; Chaurasia, Sumit; Gautam, Sudeep; Chandra, Sharat; Siddiqi, Mohammad Imran; Srivastava, Arvind K

    2014-08-25

    A series of functionalized biaryl-4-carbonitriles was synthesized in three steps and evaluated for PTP-1B inhibitory activity. Among the synthesized compounds, four biaryls 6a-d showed inhibition (IC50 58-75 μM) against in vitro PTP-1B assay possibly due to interaction with amino acid residues Lys120, Tyr46 through hydrogen bonding and aromatic-aromatic interactions, respectively. Two biaryl-4-carbonitriles 6b and 6c showed improved glucose tolerance, fasting as well as postprandial blood glucose, serum total triglycerides, and increased high-density lipoprotein-cholesterol in SLM, STZ, STZ-S and C57BL/KsJ-db/db animal models. The bioanalysis of 4'-bromo-2,3-dimethyl-5-(piperidin-1-yl)biphenyl-4-carbonitrile (6b) revealed that like insulin, it increased 2-deoxyglucose uptake in skeletal muscle cells (L6 and C2C12 myotubes). The compound 6b significantly up-regulated the genes related to the insulin signaling pathways like AMPK, MAPK including glucose transporter-4 (GLUT-4) gene in muscle tissue of C57BL/KsJ-db/db mice. Furthermore, it was observed that the compound 6b up-regulated PPARα, UCP2 and HNF4α, which are key regulator of glucose, lipid, and fatty acid metabolism. Western blot analysis of the compound 6b showed that it significantly increased the phosphorylation of AMPK and p38 MAPK and ameliorated glucose uptake in C57BL/KsJ-db/db mice through the AMPK-p38 MAPK pathway. PMID:24993155

  8. Piperlongumine selectively kills glioblastoma multiforme cells via reactive oxygen species accumulation dependent JNK and p38 activation.

    PubMed

    Liu, Ju Mei; Pan, Feng; Li, Li; Liu, Qian Rong; Chen, Yong; Xiong, Xin Xin; Cheng, Kejun; Yu, Shang Bin; Shi, Zhi; Yu, Albert Cheung-Hoi; Chen, Xiao Qian

    2013-07-19

    Piperlongumine (PL), a natural alkaloid isolated from the long pepper, may have anti-cancer properties. It selectively targets and kills cancer cells but leaves normal cells intact. Here, we reported that PL selectively killed glioblastoma multiforme (GBM) cells via accumulating reactive oxygen species (ROS) to activate JNK and p38. PL at 20μM could induce severe cell death in three GBM cell lines (LN229, U87 and 8MG) but not astrocytes in cultures. PL elevated ROS prominently and reduced glutathione levels in LN229 and U87 cells. Antioxidant N-acetyl-L-cysteine (NAC) completely reversed PL-induced ROS accumulation and prevented cell death in LN229 and U87 cells. In LN229 and U87 cells, PL-treatment activated JNK and p38 but not Erk and Akt, in a dosage-dependent manner. These activations could be blocked by NAC pre-treatment. JNK and p38 specific inhibitors, SB203580 and SP600125 respectively, significantly blocked the cytotoxic effects of PL in LN229 and U87 cells. Our data first suggests that PL may have therapeutic potential for one of the most malignant and refractory tumors GBM. PMID:23796709

  9. Antimelanogenic effect of c-phycocyanin through modulation of tyrosinase expression by upregulation of ERK and downregulation of p38 MAPK signaling pathways

    PubMed Central

    2011-01-01

    Background Pigmentation is one of the essential defense mechanisms against oxidative stress or UV irradiation; however, abnormal hyperpigmentation in human skin may pose a serious aesthetic problem. C-phycocyanin (Cpc) is a phycobiliprotein from spirulina and functions as an antioxidant and a light harvesting protein. Though it is known that spirulina has been used to reduce hyperpigmentation, little literature addresses the antimelanogenic mechanism of Cpc. Herein, we investigated the rationale for the Cpc-induced inhibitory mechanism on melanin synthesis in B16F10 melanoma cells. Methods Cpc-induced inhibitory effects on melanin synthesis and tyrosinase expression were evaluated. The activity of MAPK pathways-associated molecules such as MAPK/ERK and p38 MAPK, were also examined to explore Cpc-induced antimelanogenic mechanisms. Additionally, the intracellular localization of Cpc was investigated by confocal microscopic analysis to observe the migration of Cpc. Results Cpc significantly (P < 0.05) reduced both tyrosinase activity and melanin production in a dose-dependent manner. This phycobiliprotein elevated the abundance of intracellular cAMP leading to the promotion of downstream ERK1/2 phosphorylation and the subsequent MITF (the transcription factor of tyrosinase) degradation. Further, Cpc also suppressed the activation of p38 causing the consequent disturbed activation of CREB (the transcription factor of MITF). As a result, Cpc negatively regulated tyrosinase gene expression resulting in the suppression of melanin synthesis. Moreover, the entry of Cpc into B16F10 cells was revealed by confocal immunofluorescence localization and immunoblot analysis. Conclusions Cpc exerted dual antimelanogenic mechanisms by upregulation of MAPK/ERK-dependent degradation of MITF and downregulation of p38 MAPK-regulated CREB activation to modulate melanin formation. Cpc may have potential applications in biomedicine, food, and cosmetic industries. PMID:21988805

  10. Perfluorooctanoic acid disrupts the blood-testis barrier and activates the TNFα/p38 MAPK signaling pathway in vivo and in vitro.

    PubMed

    Lu, Yin; Luo, Bin; Li, Jing; Dai, Jiayin

    2016-04-01

    Perfluorooctanoic acid (PFOA) is correlated with male reproductive dysfunction in animals and humans, but the underlying mechanisms for this remain unknown. To explore the potential reproductive toxicity of PFOA, we studied blood-testis barrier (BTB) damage using in vivo and in vitro models. Male mice were gavage-administered PFOA (0-20 mg/kg/d) for 28 consecutive days, and breeding capacity and permeability of the Sertoli cell-based BTB were estimated. Primary Sertoli cells (SCs) were exposed to PFOA (0-500 μM) for 48 h, and transepithelial electrical resistance (TER) was assessed. Furthermore, BTB-associated protein expression, TNFα content, and phosphorylation and protein levels of the mitogen-activated protein kinase (MAPK) pathway were detected. An apparent decrease in mated and pregnant females per male mouse as well as litter weight was observed. Marked BTB damage was evidenced by increased red biotin fluorescence in the lumen tubular of the testes and the decrease in TER in SCs in vitro. The protein levels of claudin-11, connexin-43, N-cadherin, β-catenin, and occludin were significantly decreased in the testes and also in the SCs in vitro except for N-cadherin and β-catenin. TNFα content showed a dose-dependent increase in the testes and a dose- and time-dependent increase in the SCs, with the p-p38/p38 MAPK ratio also increasing in testes and SCs after PFOA exposure. Moreover, PFOA altered expressions of claudin-11, connexin-43, TNFα, and p-p38 MAPK were recovered 48 h after PFOA removal in the SCs. The SCs appeared to be target to PFOA, and the disruption of the BTB may be crucial to PFOA-induced reproductive dysfunction in mice. PMID:25743374

  11. Annexin A2 is implicated in multi-drug-resistance in gastric cancer through p38MAPK and AKT pathway.

    PubMed

    Zhang, Z D; Li, Y; Fan, Q; Zhao, B; Tan, B; Zhao, X F

    2014-01-01

    Studies have shown that Annexin A2 (ANXA2) is related with tumor proliferation, apoptosis, differentiation, invasion, migration, and drug resistance. The purpose of this study was to investigate the role and its mechanisms of ANXA2 in multi-drug-resistance (MDR) in gastric cancer. ANXA2 expression in both gastric cancer tissues and cell lines were detected by quantitative real-time PCR (RT-qPCR) and Western blotting. The cell proliferation was measured by SRB assay. The pool of siRNA against ANXA2 was designed and synthesized and then transfected into resistant gastric cancer SGC7901/DDP cells. ANXA2 expression was detected by RT-qPCR and Western blotting. Drug sensitivities of SGC7901/DDP cells to P-gp-related drug (doxorubicin) and P-gp-non-related drugs (5-FU and cisplatin) were measured by SRB assay. Expression of MDR-related genes and phosphorylation of AKT and MAPKs were also detected by RT-qPCR and Western blotting. Results showed that ANXA2 expression was significantly higher in gastric specimens than that in normal tissues, and negatively correlated with the differentiation level of gastric cancer. In addition, ANXA2 expression level was higher in SGC7901/DDP cells than that in parent SGC7901 cells. After knock-down ANXA2 expression using ANXA2 small interfering RNA, the drug sensitivity of SGC7901/DDP cells to doxorubicin, 5-FU and DDP increased. Delivery of ANXA2 siRNA significantly downregulated the expression of P-gp, MRP1 and Bcl-2, while markedly upregulated Bax in SGC7901/DDP cells. However, several other MDR factors such as GST-π, TOPO-I and TOPO-II had no obvious changes. Additionally, phosphorylation of P38MAPK and AKT, but not ERK1/2 or JNKs was specifically decreased in SGC7901/DDP cells after ANXA2 siRNA delivery. Importantly, P38MAPK and AKT inhibitor increased the drug sensitivity of SGC701/DDP cells in a similar way as ANXA2 siRNAs does. ANXA2 is involved in gastric cancer MDR through regulating p38MAPK and AKT pathways as well as

  12. Andrographolide inhibits growth of human T-cell acute lymphoblastic leukemia Jurkat cells by downregulation of PI3K/AKT and upregulation of p38 MAPK pathways.

    PubMed

    Yang, Tingfang; Yao, Shuluan; Zhang, Xianfeng; Guo, Yan

    2016-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) as a prevalent hematologic malignancy is one of the most common malignant tumors worldwide in children. Andrographolide (Andro), the major active component from Andrographis paniculata, has been shown to possess antitumor activities in several types of cancer cells. However, whether Andro would inhibit T-ALL cell growth remains unclear. In this study, we investigated the cytotoxic effect of Andro on human T-ALL Jurkat cells and explored the mechanisms of cell death. Cell apoptosis was assayed by flow cytometry, and the signaling transduction for Andro was analyzed by Western blotting. The results indicated 10 μg/mL Andro could significantly induce Jurkat cells' apoptosis, depending on the inhibition of PI3K/AKT pathway. Moreover, Andro-induced apoptosis is enhanced by AKT-selective inhibitor LY294002. ERK- or JNK-selective inhibitors PD98059 and SP600125 had no effect on Andro-induced apoptosis. In addition, p38 inhibitor SB203580 could reverse Andro-induced apoptosis in Jurkat cells. We also found that the protein expression of p-p53 and p-p38 were increased after Andro treatments. The result of an in vivo study also demonstrated Andro's dose-dependent inhibition in subcutaneous Jurkat xenografts. In conclusion, our findings explained a novel mechanism of drug action by Andro in Jurkat cells and suggested that Andro might be developed into a new candidate therapy for T-ALL patients in the coming days. PMID:27114702

  13. Lipopolysaccharide induced LOX-1 expression via TLR4/MyD88/ROS activated p38MAPK-NF-κB pathway.

    PubMed

    Zhao, Wenwen; Ma, Guixin; Chen, Xiuping

    2014-12-01

    Lectin-like receptor for oxidized low density lipoprotein (LOX-1) plays a key role in endothelial ox-LDL endocytosis, endothelial dysfunction and atherogenesis. In the present study, the effect of lipopolysaccharide (LPS) on LOX-1 expression and the underlying molecular pathways were investigated. Human umbilical vein endothelial cells (HUVECs) were treated with LPS and the protein expressions of LOX-1, TLR4, TLR2, MyD88, Nox4, Nox2, PI3K, p38MAPK, JNK, ERK, Nrf1, Nrf2 and p65 were examined by Western blotting. The intracellular reactive oxygen species (ROS) production was examined by flow cytometry with fluorescence probe DCFH2-DA. The role of TLR4, MyD88 and Nox4 were determined with specific siRNA. The endothelial ox-LDL uptake and the endothelial-monocyte adhesion were evaluated with DiI-ox-LDL and Hoechst 33342 respectively. The effect of LPS on LOX-1 expression in aorta tissue was also studied with male C57/BL6 mice by intraperitoneal injection of LPS. The results showed that LPS induced LOX-1 protein expression in a time- and concentration-dependent manner. The mRNA expression of LOX-1 was also upregulated. The protein expression of LOX-1 and phosphorylated p38MAPK, p65 was significantly enhanced by LPS both in vitro and in vivo. LPS induced LOX-1 expression was blocked by siRNA for TLR4, MyD88, and Nox4 and inhibitors for p38MAPK, NF-κB, cyclooxygenase-2, and NADPH oxidase. Both LPS induced ox-LDL uptake and endothelial-monocyte adhesion were significantly inhibited by anti-LOX-1 antibody. LPS dramatically induced LOX-1 protein expression in aorta tissues. In conclusion, our data suggested that LPS induces LOX-1 expression via TLR4/MyD88/ROS activated p38MAPK/NF-κB pathway in endothelial cells, which provides new regulatory mechanisms for LOX-1 expression. PMID:25135647

  14. Analysis of signal transduction pathways during anoxia exposure in a marine snail: a role for p38 MAP kinase and downstream signaling cascades.

    PubMed

    Larade, Kevin; Storey, Kenneth B

    2006-01-01

    The responses of members of the three main MAPK families (ERK, JNK/SAPK, p38 MAPK), as well as selected peripheral pathways, were examined in hepatopancreas of the marine periwinkle, Littorina littorea, to determine if anoxia exposure influenced the total protein content or the phosphorylation status of any key components. The content of active phospho-p38 MAPK was 2-fold higher in hepatopancreas from anoxic snails relative to controls. A 1.7-fold increase in the amount of phospho-Hsp27 and a 1.3-fold increase in phospho-CREB correlated well with the changes in p38 MAPK phosphorylation. Activation of these factors via p38 MAPK may be vital to the reorganization of metabolic responses to anoxia in hepatopancreas. No changes in components of the JNK/SAPK and ERK pathways occurred and transcription factors involved in lipid metabolism did not appear to be affected by anoxia. The present analysis of a variety of signaling pathways has implicated the p38 MAPK pathway as a key anoxia-responsive signal transduction pathway in L. littorea. PMID:16326124

  15. Piperlongumine induces apoptotic and autophagic death of the primary myeloid leukemia cells from patients via activation of ROS-p38/JNK pathways

    PubMed Central

    Xiong, Xin-xin; Liu, Ju-mei; Qiu, Xin-yao; Pan, Feng; Yu, Shang-bin; Chen, Xiao-qian

    2015-01-01

    Aim: To investigate the effects of piperlongumine (PL), an anticancer alkaloid from long pepper plants, on the primary myeloid leukemia cells from patients and the mechanisms of action. Methods: Human BM samples were obtained from 9 patients with acute or chronic myeloid leukemias and 2 patients with myelodysplastic syndrome (MDS). Bone marrow mononuclear cells (BMMNCs) were isolated and cultured. Cell viability was determined using MTT assay, and apoptosis was examined with PI staining or flow cytometry. ROS levels in the cells were determined using DCFH-DA staining and flow cytometry. Expression of apoptotic and autophagic signaling proteins was analyzed using Western blotting. Results: PL inhibited the viability of BMMNCs from the patients with myeloid leukemias (with IC50 less than 20 μmol/L), but not that of BMMNCs from a patient with MDS. Furthermore, PL (10 and 20 μmol/L) induced apoptosis of BMMNCs from the patients with myeloid leukemias in a dose-dependent manner. PL markedly increased ROS levels in BMMNCs from the patients with myeloid leukemias, whereas pretreatment with the antioxidant N-acetyl-L-cysteine abolished PL-induced ROS accumulation and effectively reduced PL-induced cytotoxicity. Moreover, PL markedly increased the expression of the apoptotic proteins (Bax, Bcl-2 and caspase-3) and autophagic proteins (Beclin-1 and LC3B), and phosphorylation of p38 and JNK in BMMNCs from the patients with myeloid leukemias, whereas pretreatment with the specific p38 inhibitor SB203580 or the specific JNK inhibitor SP600125 partially reversed PL-induced ROS production, apoptotic/autophagic signaling activation and cytotoxicity. Conclusion: Piperlongumine induces apoptotic and autophagic death of the primary myeloid leukemia cells from patients via activation of ROS-p38/JNK pathways. PMID:25619389

  16. A p38MAPK/MK2 signaling pathway leading to redox stress, cell death and ischemia/reperfusion injury

    PubMed Central

    2014-01-01

    Background Many diseases and pathological conditions are characterized by transient or constitutive overproduction of reactive oxygen species (ROS). ROS are causal for ischemia/reperfusion (IR)-associated tissue injury (IRI), a major contributor to organ dysfunction or failure. Preventing IRI with antioxidants failed in the clinic, most likely due to the difficulty to timely and efficiently target them to the site of ROS production and action. IR is also characterized by changes in the activity of intracellular signaling molecules including the stress kinase p38MAPK. While ROS can cause the activation of p38MAPK, we recently obtained in vitro evidence that p38MAPK activation is responsible for elevated mitochondrial ROS levels, thus suggesting a role for p38MAPK upstream of ROS and their damaging effects. Results Here we identified p38MAPKα as the predominantly expressed isoform in HL-1 cardiomyocytes and siRNA-mediated knockdown demonstrated the pro-oxidant role of p38MAPKα signaling. Moreover, the knockout of the p38MAPK effector MAPKAP kinase 2 (MK2) reproduced the effect of inhibiting or knocking down p38MAPK. To translate these findings into a setting closer to the clinic a stringent kidney clamping model was used. p38MAPK activity increased upon reperfusion and p38MAPK inhibition by the inhibitor BIRB796 almost completely prevented severe functional impairment caused by IR. Histological and molecular analyses showed that protection resulted from decreased redox stress and apoptotic cell death. Conclusions These data highlight a novel and important mechanism for p38MAPK to cause IRI and suggest it as a potential therapeutic target for prevention of tissue injury. PMID:24423080

  17. TGF-β1, in association with the increased expression of connective tissue growth factor, induce the hypertrophy of the ligamentum flavum through the p38 MAPK pathway.

    PubMed

    Cao, Yan-Lin; Duan, Yang; Zhu, Li-Xin; Zhan, Ye-Nan; Min, Shao-Xiong; Jin, An-Min

    2016-08-01

    Hypertrophy of the ligamentum flavum (LF) is one of the key pathomechanisms of lumbar spinal stenosis (LSS). Transforming growth factor (TGF)-β1 is abundantly expressed in hypertrophied degenerative LF tissues from LSS. However, the molecular mechanisms underling the association between TGF-β1 and LF hypertrophy have not yet been fully elucidated. In this study, we investigated the important role of the mitogen-activated protein kinase (MAPK) pathway in the pathogenesis of LSS by analyzing the expression of connective tissue growth factor (CTGF) and extracellular matrix (ECM) components (collagen I and collagen III) in TGF-β1-treated LF cells. Cell growth assay revealed that TGF-β1, in association with CTGF, enhanced the the proliferation of LF cells, and we found that TGF-β1 also elevated CTGF expression and subsequently enhanced the mRNA expression of collagen I and collagen III. The increased mRNA expression levels of CTGF, collagen I and collagen III were abolished by p38 inhibitors. Both immunofluorescence imaging and western blot analysis of p38 and p-p38 revealed the increased expression and phosphorylation of p38. Silencing the expression of p38 by siRNA in LF cells decreased the protein expression of p38, p-p38 and CTGF, as well as the mRNA expression of CTGF, collagen I and collagen III. Taken together, our findings indicate that TGF-β1, in association with the increased expression of CTGF, contribute to the homeostasis of the ECM and to the hypertrophy of LF through the p38 MAPK pathway. PMID:27279555

  18. TGF-β1, in association with the increased expression of connective tissue growth factor, induce the hypertrophy of the ligamentum flavum through the p38 MAPK pathway

    PubMed Central

    Cao, Yan-Lin; Duan, Yang; Zhu, Li-Xin; Zhan, Ye-Nan; Min, Shao-Xiong; Jin, An-Min

    2016-01-01

    Hypertrophy of the ligamentum flavum (LF) is one of the key pathomechanisms of lumbar spinal stenosis (LSS). Transforming growth factor (TGF)-β1 is abundantly expressed in hypertrophied degenerative LF tissues from LSS. However, the molecular mechanisms underling the association between TGF-β1 and LF hypertrophy have not yet been fully elucidated. In this study, we investigated the important role of the mitogen-activated protein kinase (MAPK) pathway in the pathogenesis of LSS by analyzing the expression of connective tissue growth factor (CTGF) and extracellular matrix (ECM) components (collagen I and collagen III) in TGF-β1-treated LF cells. Cell growth assay revealed that TGF-β1, in association with CTGF, enhanced the the proliferation of LF cells, and we found that TGF-β1 also elevated CTGF expression and subsequently enhanced the mRNA expression of collagen I and collagen III. The increased mRNA expression levels of CTGF, collagen I and collagen III were abolished by p38 inhibitors. Both immunofluorescence imaging and western blot analysis of p38 and p-p38 revealed the increased expression and phosphorylation of p38. Silencing the expression of p38 by siRNA in LF cells decreased the protein expression of p38, p-p38 and CTGF, as well as the mRNA expression of CTGF, collagen I and collagen III. Taken together, our findings indicate that TGF-β1, in association with the increased expression of CTGF, contribute to the homeostasis of the ECM and to the hypertrophy of LF through the p38 MAPK pathway. PMID:27279555

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

    PubMed

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

    2014-01-01

    Activated neutrophils play a significant role in the pathogenesis of many inflammatory diseases. The metabolites of marine microorganisms are increasingly employed as sources for developing new drugs; however, very few marine drugs have been studied in human neutrophils. Herein, we showed that secondary metabolites of marine Pseudomonas sp. (N11) significantly inhibited superoxide anion generation and elastase release in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-activated human neutrophils, with IC50 values of 0.67±0.38 µg/ml and 0.84±0.12 µg/ml, respectively. In cell-free systems, neither superoxide anion-scavenging effect nor inhibition of elastase activity was associated with the suppressive effects of N11. N11 inhibited the phosphorylation of p38 MAP kinase and JNK, but not Erk and Akt, in FMLP-induced human neutrophils. Also, N11 dose-dependently attenuated the transient elevation of intracellular calcium concentration in activated neutrophils. In contrast, N11 failed to alter phorbol myristate acetate-induced superoxide anion generation, and the inhibitory effects of N11 were not reversed by protein kinase A inhibitor. In conclusion, the anti-inflammatory effects of N11 on superoxide anion generation and elastase release in activated human neutrophils are through inhibiting p38 MAP kinase, JNK, and calcium pathways. Our results suggest that N11 has the potential to be developed to treat neutrophil-mediated inflammatory diseases. PMID:25474595

  20. Intranasal deferoxamine attenuates synapse loss via up-regulating the P38/HIF-1α pathway on the brain of APP/PS1 transgenic mice

    PubMed Central

    Guo, Chuang; Zhang, Yu-Xin; Wang, Tao; Zhong, Man-Li; Yang, Zhao-Hui; Hao, Li-Juan; Chai, Rui; Zhang, Shuai

    2015-01-01

    The widely recognized neuroprotective effect of iron chelators is contributed by their ability to prevent reactive oxygen species (ROS) generation via the Fenton reaction, which sequesters redox-active Fe. An additional neuroprotective mechanism of iron-chelating compounds is to regulate the transcriptional activator hypoxia-inducible factor 1α (HIF-1α). In the present study, we observed that intranasal administration of deferoxamine decreased beta-amyloid (Aβ) deposition and rescued synapse loss in the brain of Aβ precursor protein and presenilin-1 (APP/PS1) double transgenic mice. We found that deferoxamine (DFO) up-regulated HIF-1α mRNA expression and its protein level, and further induced the proteins that are encoded from HIF-1-adaptive genes, including transferrin receptor (TFR), divalent metal transporter 1 (DMT1), and brain-derived neurotrophic factor (BDNF). The effects of DFO on the induction and stabilization of HIF-1α were further confirmed in vitro. This was accompanied by a decrease of Fe in the CA3 region of the hippocampus. Western blotting studies revealed that DFO differentially enhanced the phosphorylation of mitogen-activated protein kinase (MAPK)/P38 kinase in vitro and in vivo. The results suggest that the DFO may up-regulate several HIF-1-dependent neuroprotective-adaptive genes in AD via activating P38/HIF-1α pathway, which may serve as important therapeutic targets to the disease. PMID:26082716

  1. Intermittent Hypoxia-Induced Spinal Inflammation Impairs Respiratory Motor Plasticity by a Spinal p38 MAP Kinase-Dependent Mechanism

    PubMed Central

    Huxtable, Adrianne G.; Smith, Stephanie M.C.; Peterson, Timothy J.; Watters, Jyoti J.

    2015-01-01

    Inflammation is characteristic of most clinical disorders that challenge the neural control of breathing. Since inflammation modulates neuroplasticity, we studied the impact of inflammation caused by prolonged intermittent hypoxia on an important form of respiratory plasticity, acute intermittent hypoxia (three, 5 min hypoxic episodes, 5 min normoxic intervals) induced phrenic long-term facilitation (pLTF). Because chronic intermittent hypoxia elicits neuroinflammation and pLTF is undermined by lipopolysaccharide-induced systemic inflammation, we hypothesized that one night of intermittent hypoxia (IH-1) elicits spinal inflammation, thereby impairing pLTF by a p38 MAP kinase-dependent mechanism. pLTF and spinal inflammation were assessed in anesthetized rats pretreated with IH-1 (2 min hypoxia, 2 min normoxia; 8 h) or sham normoxia and allowed 16 h for recovery. IH-1 (1) transiently increased IL-6 (1.5 ± 0.2-fold; p = 0.02) and inducible nitric oxide synthase (iNOS) (2.4 ± 0.4-fold; p = 0.01) mRNA in cervical spinal homogenates, (2) elicited a sustained increase in IL-1β mRNA (2.4 ± 0.2-fold; p < 0.001) in isolated cervical spinal microglia, and (3) abolished pLTF (−1 ± 5% vs 56 ± 10% in controls; p < 0.001). pLTF was restored after IH-1 by systemic NSAID administration (ketoprofen; 55 ± 9%; p < 0.001) or spinal p38 MAP kinase inhibition (58 ± 2%; p < 0.001). IH-1 increased phosphorylated (activated) p38 MAP kinase immunofluorescence in identified phrenic motoneurons and adjacent microglia. In conclusion, IH-1 elicits spinal inflammation and impairs pLTF by a spinal p38 MAP kinase-dependent mechanism. By targeting inflammation, we may develop strategies to manipulate respiratory motor plasticity for therapeutic advantage when the respiratory control system is compromised (e.g., sleep apnea, apnea of prematurity, spinal injury, or motor neuron disease). PMID:25926462

  2. SIRT1 increases YAP- and MKK3-dependent p38 phosphorylation in mouse liver and human hepatocellular carcinoma

    PubMed Central

    Zhang, Xiao; Qiao, Yongxia; Liu, Xiangfan; Chang, Yefei; Yu, Yongchun; Sun, Fenyong; Wang, Jiayi

    2016-01-01

    Both oncoprotein and tumor-suppressor activity have been reported for SIRTUIN1 (SIRT1) and p38 in many types of cancer. The effect of SIRT1 on p38 phosphorylation (p-p38) remains controversial and may be organ- and cell-specific. We found that SIRT1 is essential for maintaining liver size and weight in mice. SIRT1 levels were elevated in human HCC compared to adjacent normal liver tissue, and its expression correlated positively with p-p38 levels. Additionally, SIRT1-activated p38 increased liver cancer malignancy. SIRT1 increased phosphorylation and nuclear accumulation of p38, possibly by increasing MKK3 expression. SIRT1 also induced YAP expression, which in turn increased MKK3 transcription. Positive correlations between SIRT1, YAP, MKK3, and p-p38 levels indicate that blocking their activity may prove helpful in treating HCC. PMID:26824501

  3. Cold-inducible RNA-binding protein promotes epithelial-mesenchymal transition by activating ERK and p38 pathways.

    PubMed

    Lee, Hae Na; Ahn, Sung-Min; Jang, Ho Hee

    2016-09-01

    Transforming growth factor-β1 (TGF-β1), a potent inducer of epithelial-to-mesenchymal transition (EMT), upregulates the cold-inducible RNA-binding protein (CIRP). The link between CIRP and EMT, however, remains unknown. To determine the role of CIRP in EMT, we performed CIRP knockdown and overexpression experiments in in vitro TGF-β1-induced EMT models. We found that CIRP overexpression promoted the downregulation of epithelial markers and the upregulation of mesenchymal markers after TGF-β1 treatment for EMT induction. It also promoted cell migration and invasion, key features of EMT. In contrast, CIRP knockdown inhibited the downregulation of epithelial markers and the upregulation of mesenchymal markers after TGF-β1 treatment for EMT induction. In addition, it also inhibited cell migration and invasion. Furthermore, we demonstrated that the RNA-recognition motif in CIRP is essential for the role of CIRP in EMT. At the downstream level, CIRP knockdown downregulated Snail, key transcriptional regulator of EMT, while CIRP overexpression upregulated it. We found out that the link between CIRP and Snail is mediated by ERK and p38 pathways. EMT is a critical component of carcinoma metastasis and invasion. As demonstrated in this study, the biological role of CIRP in EMT may explain why CIRP overexpression has been associated with a bad prognosis in cancer patients. PMID:27395339

  4. A p38(MAPK)/HIF-1 pathway initiated by UVB irradiation is required to induce Noxa and apoptosis of human keratinocytes.

    PubMed

    Nys, Kris; Van Laethem, An; Michiels, Carine; Rubio, Noemi; Piette, Jacques G; Garmyn, Maria; Agostinis, Patrizia

    2010-09-01

    The signal transduction pathways leading to apoptosis of human keratinocytes responding to UVB irradiation are complex and not completely understood. Previously, we reported that in UVB-irradiated keratinocytes, p38(MAPK) instigates Bcl-2-associated X protein (Bax) activation and mitochondrial apoptosis. However, the molecular mechanism underlying the pro-apoptotic function of p38(MAPK) remained unclear. Here, we show that in UVB-treated human primary keratinocytes the activation of p38(MAPK) is necessary to upregulate Noxa, a BH3-only pro-apoptotic dominantly induced by UVB and required for apoptosis. Whereas p53-silencing was marginally cytoprotective and poorly affected Noxa expression, p38(MAPK) inhibition in p53-silenced keratinocytes or in p53(-/-) cells could still efficiently prevent Noxa induction and intrinsic apoptosis after UVB, indicating that p38(MAPK) signals mainly through p53-independent mechanisms. Furthermore, p38(MAPK) was required for the induction and activation of hypoxia-inducible factor 1 (HIF-1) in response to UVB, and HIF-1 knockdown reduced Noxa expression and apoptosis. In UVB-irradiated keratinocytes, Noxa targeted the anti-apoptotic myeloid cell leukemia sequence 1 (Mcl-1) for degradation, and small-interfering RNA (siRNA)-mediated knockdown of Noxa or p38(MAPK) inhibition restored levels of Mcl-1 and abolished apoptosis. Thus, the pro-apoptotic mechanisms orchestrated by p38(MAPK) in human keratinocytes in response to UVB involve an HIF-1/Noxa axis, which prompts the downregulation of anti-apoptotic Mcl-1, thereby favoring Bax-mediated mitochondrial apoptosis of UVB-damaged keratinocytes. PMID:20393480

  5. Epithelial Control of Gut-Associated Lymphoid Tissue Formation through p38α-Dependent Restraint of NF-κB Signaling.

    PubMed

    Caballero-Franco, Celia; Guma, Monica; Choo, Min-Kyung; Sano, Yasuyo; Enzler, Thomas; Karin, Michael; Mizoguchi, Atsushi; Park, Jin Mo

    2016-03-01

    The protein kinase p38α mediates cellular responses to environmental and endogenous cues that direct tissue homeostasis and immune responses. Studies of mice lacking p38α in several different cell types have demonstrated that p38α signaling is essential to maintaining the proliferation-differentiation balance in developing and steady-state tissues. The mechanisms underlying these roles involve cell-autonomous control of signaling and gene expression by p38α. In this study, we show that p38α regulates gut-associated lymphoid tissue (GALT) formation in a noncell-autonomous manner. From an investigation of mice with intestinal epithelial cell-specific deletion of the p38α gene, we find that p38α serves to limit NF-κB signaling and thereby attenuate GALT-promoting chemokine expression in the intestinal epithelium. Loss of this regulation results in GALT hyperplasia and, in some animals, mucosa-associated B cell lymphoma. These anomalies occur independently of luminal microbial stimuli and are most likely driven by direct epithelial-lymphoid interactions. Our study illustrates a novel p38α-dependent mechanism preventing excessive generation of epithelial-derived signals that drive lymphoid tissue overgrowth and malignancy. PMID:26792803

  6. Ligustrazine attenuates oxidative stress-induced activation of hepatic stellate cells by interrupting platelet-derived growth factor-β receptor-mediated ERK and p38 pathways

    SciTech Connect

    Zhang, Feng; Ni, Chunyan; Kong, Desong; Zhang, Xiaoping; Zhu, Xiaojing; Chen, Li; Lu, Yin; Zheng, Shizhong

    2012-11-15

    Hepatic fibrosis represents a frequent event following chronic insult to trigger wound healing reactions with accumulation of extracellular matrix (ECM) in the liver. Activation of hepatic stellate cells (HSCs) is the pivotal event during liver fibrogenesis. Compelling evidence indicates that oxidative stress is concomitant with liver fibrosis irrespective of the underlying etiology. Natural antioxidant ligustrazine exhibits potent antifibrotic activities, but the mechanisms are poorly understood. Our studies were to investigate the ligustrazine effects on HSC activation stimulated by hydrogen peroxide (H{sub 2}O{sub 2}), an in vitro model mimicking the oxidative stress in liver fibrogenesis, and to elucidate the possible mechanisms. Our results demonstrated that H{sub 2}O{sub 2} at 5 μM significantly stimulated HSC proliferation and expression of marker genes of HSC activation; whereas ligustrazine dose-dependently suppressed proliferation and induced apoptosis in H{sub 2}O{sub 2}-activated HSCs, and attenuated expression of fibrotic marker genes. Mechanistic investigations revealed that ligustrazine reduced platelet-derived growth factor-β receptor (PDGF-βR) expression and blocked the phosphorylation of extracellular regulated protein kinase (ERK) and p38 kinase, two downstream effectors of PDGF-βR. Further molecular evidence suggested that ligustrazine interruption of ERK and p38 pathways was dependent on the blockade of PDGF-βR and might be involved in ligustrazine reduction of fibrotic marker gene expression under H{sub 2}O{sub 2} stimulation. Furthermore, ligustrazine modulated some proteins critical for HSC activation and ECM homeostasis in H{sub 2}O{sub 2}-stimulated HSCs. These data collectively indicated that ligustrazine could attenuate HSC activation caused by oxidative stress, providing novel insights into ligustrazine as a therapeutic option for hepatic fibrosis. Highlights: ► Ligustrazine inhibits oxidative stress-induced HSC activation.

  7. Arctigenin, a dietary phytoestrogen, induces apoptosis of estrogen receptor-negative breast cancer cells through the ROS/p38 MAPK pathway and epigenetic regulation.

    PubMed

    Hsieh, Chia-Jung; Kuo, Po-Lin; Hsu, Ying-Chan; Huang, Ya-Fang; Tsai, Eing-Mei; Hsu, Ya-Ling

    2014-02-01

    This study investigates the anticancer effect of arctigenin (ATG), a natural lignan product of Arctium lappa L., in human breast cancer MDA-MB-231 cells. Results indicate that ATG inhibits MDA-MB-231 cell growth by inducing apoptosis in vitro and in vivo. ATG triggers the mitochondrial caspase-independent pathways, as indicated by changes in Bax/Bcl-2 ratio, resulting in AIF and EndoG nuclear translocation. ATG increased cellular reactive oxygen species (ROS) production by increasing p22(phox)/NADPH oxidase 1 interaction and decreasing glutathione level. ATG clearly increases the activation of p38 MAPK, but not JNK and ERK1/2. Antioxidant EUK-8, a synthetic catalytic superoxide and hydrogen peroxide scavenger, significantly decreases ATG-mediated p38 activation and apoptosis. Blocking p38 with a specific inhibitor suppresses ATG-mediated Bcl-2 downregulation and apoptosis. Moreover, ATG activates ATF-2, a transcription factor activated by p38, and then upregulates histone H3K9 trimethylation in the Bcl-2 gene promoter region, resulting in Bcl-2 downregulation. Taken together, the results demonstrate that ATG induces apoptosis of MDA-MB-231 cells via the ROS/p38 MAPK pathway and epigenetic regulation of Bcl-2 by upregulation of histone H3K9 trimethylation. PMID:24140706

  8. Naringin inhibits the invasion and migration of human glioblastoma cell via downregulation of MMP-2 and MMP-9 expression and inactivation of p38 signaling pathway.

    PubMed

    Aroui, Sonia; Najlaoui, Feten; Chtourou, Yassine; Meunier, Annie-Claire; Laajimi, Amel; Kenani, Abderraouf; Fetoui, Hamadi

    2016-03-01

    Gliomas are the most common and malignant primary brain tumors. They are associated with a poor prognosis despite the availability of multiple therapeutic options. Naringin, a common dietary flavonoid abundantly present in fruits and vegetables, is believed to possess strong anti-proliferative and anti-cancer properties. However, there are no reports describing its effects on the invasion and migration of glioblastoma cell lines. Our results showed that the treatment of U251 glioma cell lines with different concentrations of naringin inhibited the invasion and migration of these cells. In addition, we revealed a decrease in the levels of matrix metalloproteinases (MMP-2) and (MMP-9) expression as well as proteinase activity in U251 glioma cells. In contrast, the expression of tissue inhibitor of metalloproteinases (TIMP-1) and (TIMP-2) was increased. Furthermore, naringin treatment decreased significantly the phosphorylated level of p38. Combined treatment with a p38 inhibitor (SB203580) resulted in the synergistic reduction of MMP-2 and MMP-9 expressions correlated with an increase of TIMP-1 and TIMP-2 expressions and the anti-invasive properties. However, p38 chemical activator (anisomycin) could block these effects produced by naringin, suggesting a direct downregulation of the p38 signaling pathway. These data suggest that naringin may have therapeutic potential for controlling invasiveness of malignant gliomas by inhibiting of p38 signal transduction pathways. PMID:26474590

  9. Salinomycin causes migration and invasion of human fibrosarcoma cells by inducing MMP-2 expression via PI3-kinase, ERK-1/2 and p38 kinase pathways.

    PubMed

    Yu, Seon-Mi; Kim, Song Ja

    2016-06-01

    Salinomycin (SAL) is a polyether ionophore antibiotic that has recently been shown to regulate a variety of cellular responses in various human cancer cells. However, the effects of SAL on metastatic capacity of HT1080 human fibrosarcoma cells have not been elucidated. We investigated the effect of SAL on migration and invasion, with emphasis on the expression and activation of matrix metalloproteinase (MMP)-2 in HT1080 human fibrosarcoma cells. Treatment of SAL promoted the expression and activation of MMP-2 in a dose- and time-dependent manner, as detected by western blot analysis, gelatin zymography, and real-time polymerase chain reaction. SAL also increased metastatic capacities, as determined by an increase in the migration and invasion of cells using the wound healing assay and the invasion assay, respectively. To confirm the detailed molecular mechanisms of these effects, we measured the activation of phosphoinositide 3 kinase (PI3-kinase) and mitogen-activated protein kinase (MAPK)s (ERK-1/2 and p38 kinase), as detected by the phosphorylated proteins through western blot analysis. SAL treatment increased the phosphorylation of Akt and MAPKs. Inhibition of PI3-kinase, ERK-1/2, and p38 kinase with LY294002, PD98059, and SB203580, respectively, in the presence of SAL suppressed the metastatic capacity by reducing MMP-2 expression, as determined by gelatin zymography. Our results indicate that the PI3-kinase and MAPK signaling pathways are involved in migration and invasion of HT1080 through induction of MMP-2 expression and activation. In conclusion, SAL significantly increases the metastatic capacity of HT1080 cells by inducing MMP-2 expression via PI3-kinase and MAPK pathways. Our results suggest that SAL may be a potential agent for the study of cancer metastatic capacities. PMID:27035160

  10. Lipopolysaccharide Decreases Single Immunoglobulin Interleukin-1 Receptor-related Molecule (SIGIRR) Expression by Suppressing Specificity Protein 1 (Sp1) via the Toll-like Receptor 4 (TLR4)-p38 Pathway in Monocytes and Neutrophils*

    PubMed Central

    Ueno-Shuto, Keiko; Kato, Kosuke; Tasaki, Yukihiro; Sato, Miki; Sato, Keizo; Uchida, Yuji; Sakai, Hiromichi; Ono, Tomomi; Suico, Mary Ann; Mitsutake, Kazunori; Tokutomi, Naofumi; Kai, Hirofumi; Shuto, Tsuyoshi

    2014-01-01

    Single immunoglobulin interleukin-1 receptor-related molecule (SIGIRR) is one of the immunoglobulin-like membrane proteins that is crucial for negative regulation of toll-like receptor 4 (TLR4) and interleukin-1 receptor. Despite the importance of understanding its expression and function, knowledge is limited on the regulatory mechanism in the epithelial tissues, such as the liver, lung, and gut, where its predominant expression is originally described. Here, we found expression of SIGIRR in non-epithelial innate immune cells, including primary peripheral blood monocytes, polymorphonuclear neutrophils, monocytic RAW264 cells, and neutrophilic-differentiated HL-60 cells. Consistent with previous findings in epithelial tissues, SIGIRR gene and protein expression were also down-regulated by LPS treatment in a time-dependent manner in primary blood monocytes and polymorphonuclear neutrophils. A reduction was also observed in RAW264 and differentiated HL-60 cells. Notably, exogenous introduction of the dominant negative form of TLR4 and siRNA of p38 resulted in inhibition of LPS-induced SIGIRR down-regulation, whereas treatment with p38 activator anisomycin showed a dose-dependent decrease in SIGIRR expression, suggesting TLR4-p38 signal as a critical pathway for LPS-induced SIGIRR down-regulation. Finally, reporter gene and chromatin immunoprecipitation assays demonstrated that Sp1 is a key factor that directly binds to the proximal promoter of SIGIRR gene and consequently regulates basal SIGIRR expression, which is negatively regulated by the LPS-dependent TLR4-p38 pathway. In summary, the data precisely demonstrate how LPS down-regulates SIGIRR expression and provide a role of LPS signal that counteracts Sp1-dependent basal promoter activation of SIGIRR gene via TLR4-p38 pathway in non-epithelial innate immune cells. PMID:24821721

  11. Andrographolide inhibits growth of human T-cell acute lymphoblastic leukemia Jurkat cells by downregulation of PI3K/AKT and upregulation of p38 MAPK pathways

    PubMed Central

    Yang, Tingfang; Yao, Shuluan; Zhang, Xianfeng; Guo, Yan

    2016-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) as a prevalent hematologic malignancy is one of the most common malignant tumors worldwide in children. Andrographolide (Andro), the major active component from Andrographis paniculata, has been shown to possess antitumor activities in several types of cancer cells. However, whether Andro would inhibit T-ALL cell growth remains unclear. In this study, we investigated the cytotoxic effect of Andro on human T-ALL Jurkat cells and explored the mechanisms of cell death. Cell apoptosis was assayed by flow cytometry, and the signaling transduction for Andro was analyzed by Western blotting. The results indicated 10 μg/mL Andro could significantly induce Jurkat cells’ apoptosis, depending on the inhibition of PI3K/AKT pathway. Moreover, Andro-induced apoptosis is enhanced by AKT-selective inhibitor LY294002. ERK- or JNK-selective inhibitors PD98059 and SP600125 had no effect on Andro-induced apoptosis. In addition, p38 inhibitor SB203580 could reverse Andro-induced apoptosis in Jurkat cells. We also found that the protein expression of p-p53 and p-p38 were increased after Andro treatments. The result of an in vivo study also demonstrated Andro’s dose-dependent inhibition in subcutaneous Jurkat xenografts. In conclusion, our findings explained a novel mechanism of drug action by Andro in Jurkat cells and suggested that Andro might be developed into a new candidate therapy for T-ALL patients in the coming days. PMID:27114702

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  14. FXR-induced secretion of FGF15/19 inhibits CYP27 expression in cholangiocytes through p38 kinase pathway

    PubMed Central

    Jung, Dongju; York, J. Philippe; Wang, Li; Yang, Chaofeng; Zhang, Aijun; Francis, Heather L.; Webb, Paul; McKeehan, Wallace L.; Alpini, Gianfranco; LeSage, Gene D.; Moore, David D.

    2014-01-01

    Cholangiocytes, bile duct lining cells, actively adjust the amount of cholesterol and bile acids in bile through expression of enzymes and channels involved in transportation and metabolism of the cholesterol and bile acids. Herein, we report molecular mechanisms regulating bile acid biosynthesis in cholangiocytes. Among the cytochrome p450 (Cyp) enzymes involved in bile acid biosynthesis, sterol 27-hydroxylase (Cyp27) that is the rate-limiting enzyme for the acidic pathway of bile acid biosynthesis expressed in cholangiocytes. Expression of other Cyp enzymes for the basic bile acid biosynthesis was hardly detected. The Cyp27 expression was negatively regulated by a hydrophobic bile acid through farnesoid X receptor (FXR), a nuclear receptor activated by bile acid ligands. Activated FXR exerted the negative effects by inducing an expression of fibroblast growth factor 15/19 (FGF15/19). Similar to its repressive function against cholesterol 7α-hydroxylase (Cyp7a1) expression in hepatocytes, secreted FGF15/19 triggered Cyp27 repression in cholangiocytes through interaction with its cognate receptor fibroblast growth factor receptor 4 (FGFR4). The involvements of FXR and FGFR4 for the bile acid-induced Cyp27 repression were confirmed in vivo using knockout mouse models. Different from the signaling in hepatocytes, wherein the FGF15/19-induced repression signaling is mediated by c-Jun N-terminal kinase (JNK), FGF15/19-induced Cyp27 repression in cholangiocytes was mediated by p38 kinase. Thus, the results collectively suggest that cholangiocytes may be able to actively regulate bile acid biosynthesis in cholangiocytes and even hepatocyte by secreting FGF15/19. We suggest the presence of cholangiocyte-mediated intrahepatic feedback loop in addition to the enterohepatic feedback loop against bile acid biosynthesis in the liver. PMID:24068255

  15. Immunomodulatory Effects of Lippia sidoides Extract: Induction of IL-10 Through cAMP and p38 MAPK-Dependent Mechanisms

    PubMed Central

    Rajgopal, Arun; Rebhun, John F.; Burns, Charlie R.; Scholten, Jeffrey D.; Balles, John A.

    2015-01-01

    Abstract Lippia sidoides is an aromatic shrub that grows wild in the northeastern region of Brazil. In local traditional medicine, the aerial portions of this species are used as anti-infectives, antiseptics, spasmolytics, sedatives, hypotensives, and anti-inflammatory agents. In this research, we evaluate the potential immunological properties of Lippia extract through in vitro analysis of its ability to modulate intracellular cyclic adenosine monophosphate (cAMP) levels and interleukin-10 (IL-10) production. These results show that Lippia extract increases intracellular cAMP through the inhibition of phosphodiesterase activity. They also demonstrate that Lippia extract increases IL-10 production in THP-1 monocytes through both an increase in intracellular cAMP and the activation of p38 MAPK. These results suggest that the Lippia-mediated inhibition of phosphodiesterase activity and the subsequent increase in intracellular cAMP may explain some of the biological activities associated with L. sidoides. In addition, the anti-inflammatory activity of L. sidoides may also be due, in part, to its ability to induce IL-10 production through the inhibition of cyclic nucleotide-dependent phosphodiesterase activity and by its activation of the p38 MAPK pathway. PMID:25599252

  16. Death receptor 6 (DR6) is required for mouse B16 tumor angiogenesis via the NF-κB, P38 MAPK and STAT3 pathways

    PubMed Central

    Yang, X; Shi, B; Li, L; Xu, Z; Ge, Y; Shi, J; Liu, Y; Zheng, D

    2016-01-01

    Although death receptor 6 (DR6) is aberrantly expressed in certain cancer cell lines, its function, signaling pathway and potential clinical significance in tumor progression are not well characterized. We report here that knocking down DR6 in the mouse B16 cell line has no effect on B16 cell death in vitro but suppresses xenograft B16 tumor growth by preventing tumor blood vessel formation in vivo. Deficiency of DR6 changes cytokine expression and secretion; in particular, it inhibits the proinflammatory cytokine interleukin-6 (IL-6), which is able to induce the expression of the angiogenesis-related factors: vascular endothelial growth factor-A, platelet-derived growth factor-β, vascular endothelial growth factor-D and platelet-derived growth factor receptor-α. Further experiments demonstrate that DR6-dependent angiogenesis is involved in the IL-6/P38 MAPK and IL-6/STAT3 pathways. Our novel findings demonstrate for the first time that DR6 expression in B16 cells facilitates tumor growth by accelerating tumor angiogenesis. Moreover, these results suggest that DR6 is involved in three important intracellular pathways that lead to homeostatic angiogenesis in tumor growth. PMID:26950598

  17. AMPKα1 overexpression alleviates the hepatocyte model of nonalcoholic fatty liver disease via inactivating p38MAPK pathway.

    PubMed

    Zhang, Hong-Ai; Yang, Xiao-Yan; Xiao, Yan-Feng

    2016-05-27

    Nonalcoholic fatty liver disease (NAFLD) has a wide spectrum of liver damage with a worldwide prevalence of almost 20%. AMP-activated protein kinase α1 (AMPKα1) is an energy sensor that plays a key role in regulating lipid metabolism of the liver. This study explores the role of AMPKα1 overexpression in a steatotic hepatocyte model. The results displayed that the AMPKα1 overexpression suppressed lipid accumulation in the cytoplasm, decreased triglyceride levels, maintained the survival of steatotic hepatocyte model with decreased cell apoptosis and increased survival rate. Besides, AMPKα1 overexpression promoted the expression of lipid catabolism-related genes, reduced the level of anabolism-related genes, alleviated the inflammatory response by reducing pro-inflammatory cytokines and increasing anti-inflammatory cytokines. Moreover, AMPKα1 overexpression could inhibit the activation of p38 mitogen-activated protein kinase (p38MAPK). Finally, Anisomycin, a frequently-used activator of p38MAPK, reversed the inhibitory effect of pc-AMPKα1 on the expression of p-p38MAPK, suggesting that AMPKα1 overexpression alleviates inflammatory response through the inactivation of p38MAPK. These results indicated that AMPKα1 may serve as a novel target for treatment of NAFLD. PMID:27109475

  18. Cordycepin induced MA-10 mouse Leydig tumor cell apoptosis by regulating p38 MAPKs and PI3K/AKT signaling pathways

    PubMed Central

    Pan, Bo-Syong; Wang, Yang-Kao; Lai, Meng-Shao; Mu, Yi-Fen; Huang, Bu-Miin

    2015-01-01

    The p38 MAPKs play important roles in the regulation of balance between cell survival and cell death on the development of various cancers. However, the roles of p38 MAPKs regulating apoptotic effects on Leydig tumor cells remain unclear. In the present study, we showed that cordycepin (3′-deoxyadenosine) selectively induced apoptosis in MA-10 mouse Leydig tumor cells through regulating the p38 MAPK and PI3K/AKT signaling pathways. Cordycepin reduced viability in MA-10, TM4, and NT2/D1 cells, but not cause cell death of primary mouse Leydig cells on moderate concentration. Cordycepin increased reactive oxygen species (ROS) levels, which is associated with the induction of apoptosis as characterized by positive Annexin V binding, activation of caspase-3, and cleavage of PARP. Inhibition of p38 MAPKs activity by SB203580 significantly prevented cordycepin-induced apoptosis in MA-10 cells. Co-treatment with wortmannin or the autophagy inhibitor 3-methyladenine (3-MA) elevated levels of apoptosis in cordycepin-treated MA-10 cells. Moreover, cordycepin activated p53, p21 and TGFß; and downregulated CDK2. The antitumour activity of cordycepin-treated MA-10 cells was significantly distinct in severe combined immunodeficiency (SCID) mice in vivo. These results suggested that cordycein is a highly selective treatment to induce MA-10 cells apoptosis via p38 MAPKs signaling. PMID:26303320

  19. Berberine induces dedifferentiation by actin cytoskeleton reorganization via phosphoinositide 3-kinase/Akt and p38 kinase pathways in rabbit articular chondrocytes.

    PubMed

    Yu, Seon-Mi; Cho, Hongsik; Kim, Gwang-Hoon; Chung, Ki-Wha; Seo, Sung-Yum; Kim, Song-Ja

    2016-04-01

    Osteoarthritis is a nonrheumatologic joint disease characterized by progressive degeneration of the cartilage extracellular matrix. Berberine (BBR) is an isoquinoline alkaloid used in traditional Chinese medicine, the majority of which is extracted from Huang Lian (Coptis chinensis). Although numerous studies have revealed the anticancer activity of BBR, its effects on normal cells, such as chondrocytes, and the molecular mechanisms underlying its actions remain elusive. Therefore, we examined the effects of BBR on rabbit articular chondrocytes, and the underlying molecular mechanisms, focusing on actin cytoskeletal reorganization. BBR induced dedifferentiation by inhibiting activation of phosphoinositide-3(PI3)-kinase/Akt and p38 kinase. Furthermore, inhibition of p38 kinase and PI3-kinase/Akt with SB203580 and LY294002, respectively, accelerated the BBR-induced dedifferentiation. BBR also caused actin cytoskeletal architecture reorganization and, therefore, we investigated if these effects were involved in the dedifferentiation. Disruption of the actin cytoskeleton by cytochalasin D reversed the BBR-induced dedifferentiation by activating PI3-kinase/Akt and p38 kinase. In contrast, the induction of actin filament aggregation by jasplakinolide accelerated the BBR-induced dedifferentiation via PI3-kinase/Akt inhibition and p38 kinase activation. Taken together, these data suggest that BBR strongly induces dedifferentiation, and actin cytoskeletal reorganization is a crucial requirement for this effect. Furthermore, the dedifferentiation activity of BBR appears to be mediated via PI3-kinase/Akt and p38 kinase pathways in rabbit articular chondrocytes. PMID:26851252

  20. Up-regulation of interleukin-8 by novel small cytoplasmic molecules of nontypeable Haemophilus influenzae via p38 and extracellular signal-regulated kinase pathways.

    PubMed

    Wang, Beinan; Cleary, P Patrick; Xu, Haidong; Li, Jian-Dong

    2003-10-01

    Nontypeable Haemophilus influenzae (NTHI) is an important etiological agent of otitis media (OM) and of exacerbated chronic obstructive pulmonary diseases (COPD). Inflammation is a hallmark of both diseases. Interleukin-8 (IL-8), one of the important inflammatory mediators, is induced by NTHI and may play a significant role in the pathogenesis of these diseases. Our studies demonstrated that a soluble cytoplasmic fraction (SCF) from NTHI induced much greater IL-8 expression by human epithelial cells than did NTHI lipooligosaccharides and envelope proteins. The IL-8-inducing activity was associated with molecules of < or =3 kDa from SCF and was peptidase and lipase sensitive, suggesting that small lipopeptides are responsible for the strong IL-8 induction. Moreover, multiple intracellular signaling pathways were activated in response to cytoplasmic molecules. The results indicated that the p38 mitogen-activated protein kinase (MAPK) and Src-dependent Raf-1-Mek1/2-extracellular signal-regulated kinase mitogen-activated protein kinase (ERK MAPK) pathways are required for NTHI-induced IL-8 production. In contrast, the phosphatidylinositol 3-kinase (PI3K)-Akt pathway did not affect IL-8 expression, although this pathway was concomitantly activated upon exposure to NTHI SCF. The PI3K-Akt pathway was also directly activated by IL-8 and significantly inhibited by an antagonist of IL-8 receptors during NTHI stimulation. These results indicated that the PI3K-Akt pathway is activated in response to IL-8 that is induced by NTHI and may lead to other important epithelial cell responses. This work provides insight into essential molecular and cellular events that may impact on the pathogenesis of OM and COPD and identifies rational targets for anti-inflammatory intervention. PMID:14500470

  1. SHP-1-Pyk2-Src protein complex and p38 MAPK pathways independently regulate IL-10 production in lipopolysaccharide-stimulated macrophages.

    PubMed

    Okenwa, Chinonso; Kumar, Ashok; Rego, Dorothy; Konarski, Yulia; Nilchi, Ladan; Wright, Kathryn; Kozlowski, Maya

    2013-09-01

    The role of tyrosine phosphatase Src homology region 2 domain-containing phosphatase (SHP)-1 in LPS-activated cytokine production and inflammation was investigated by determining TNF-α and IL-10 production in splenic macrophages employing SHP-1-null (me/me) mouse model. LPS-stimulated me/me splenic macrophages secreted significantly less IL-10 with concomitantly elevated levels of TNF-α compared with wild-type (WT) macrophages irrespective of LPS dose and duration of stimulation. IL-10 significantly inhibited LPS-induced TNF-α production in both me/me and WT macrophages. The critical requirement for SHP-1 in regulating LPS-induced IL-10 and TNF-α production was confirmed by interfering with SHP-1 expression in WT macrophages and by reconstituting me/me macrophages with the SHP-1 gene. To delineate the role of SHP-1 in positive regulation of LPS-induced IL-10 production, signaling proteins representing SHP-1 targets were examined. The results reveal that tyrosine kinases Src and proline-rich tyrosine kinase 2 (Pyk2) regulate SHP-1-dependent LPS-induced IL-10 production and infer that optimal LPS-induced IL-10 production requires an assembly of a protein complex consisting of SHP-1-Pyk2-Src proteins. Moreover, LPS-induced IL-10 production also requires activation of the p38 MAPK independent of SHP-1 function. Overall, to our knowledge our results show for the first time that SHP-1 acts as a positive regulator of LPS-induced IL-10 production in splenic macrophages through two distinct and independent SHP-1-Pyk2-Src and p38 MAPK pathways. PMID:23904162

  2. Inhibitory Effect of Dried Pomegranate Concentration Powder on Melanogenesis in B16F10 Melanoma Cells; Involvement of p38 and PKA Signaling Pathways.

    PubMed

    Kang, Su Jin; Choi, Beom Rak; Lee, Eun Kyoung; Kim, Seung Hee; Yi, Hae Yeon; Park, Hye Rim; Song, Chang Hyun; Lee, Young Joon; Ku, Sae Kwang

    2015-01-01

    Plants rich in antioxidant substances may be useful for preventing skin aging. Pomegranates, containing flavonoids and other polyphenolic compounds, are widely consumed due to their beneficial properties. We examined the underlying mechanisms of dried pomegranate concentrate powder (PCP) on melanin synthesis in B16F10 melanoma cells. The antioxidant effects of PCP were determined by measuring free radical scavenging capacity and transcript levels of antioxidant enzymes. To explore the inhibitory effects of PCP on melanin synthesis, we measured tyrosinase activity and melanin content in α-melanocyte stimulating hormone (α-MSH)-stimulated B16F10 cells. In addition, the levels of tyrosinase-related protein-1 (TRP-1), TRP-2, tyrosinase, and microphthalmia-associated transcription factor (MITF) expression were determined by Western blotting. Changes in the phosphorylation status of protein kinase A (PKA), cAMP response element-binding protein (CREB), mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3-kinase (PI3K), serine/threonine kinase Akt, and glycogen kinase 3β (GSK3β) were also examined. The free radical scavenging activity of PCP increased in a dose-dependent manner. In PCP-treated B16F10 cells, transcript levels of glutathione peroxidase-1 (GPx-1) were increased compared with α-MSH-stimulated cells. In addition, PCP led to the down-regulation of phospho-p38, phospho-PKA, phospho-CREB, phospho-GSK3β, MITF, and TRP-1 compared with α-MSH-stimulated B16F10 cells. We believe this effect may be associated with PCP activity, which leads to the inhibition of melanin production and tyrosinase activity. These results suggest that PCP decreases tyrosinase activity and melanin production via inactivation of the p38 and PKA signaling pathways, and subsequently decreases phosphorylation of CREB, MITF, and melanogenic enzymes. These observations provided new insights on the molecular mechanisms of the skin-whitening property of PCP. PMID:26473849

  3. Inhibitory Effect of Dried Pomegranate Concentration Powder on Melanogenesis in B16F10 Melanoma Cells; Involvement of p38 and PKA Signaling Pathways

    PubMed Central

    Kang, Su Jin; Choi, Beom Rak; Lee, Eun Kyoung; Kim, Seung Hee; Yi, Hae Yeon; Park, Hye Rim; Song, Chang Hyun; Lee, Young Joon; Ku, Sae Kwang

    2015-01-01

    Plants rich in antioxidant substances may be useful for preventing skin aging. Pomegranates, containing flavonoids and other polyphenolic compounds, are widely consumed due to their beneficial properties. We examined the underlying mechanisms of dried pomegranate concentrate powder (PCP) on melanin synthesis in B16F10 melanoma cells. The antioxidant effects of PCP were determined by measuring free radical scavenging capacity and transcript levels of antioxidant enzymes. To explore the inhibitory effects of PCP on melanin synthesis, we measured tyrosinase activity and melanin content in α-melanocyte stimulating hormone (α-MSH)-stimulated B16F10 cells. In addition, the levels of tyrosinase-related protein-1 (TRP-1), TRP-2, tyrosinase, and microphthalmia-associated transcription factor (MITF) expression were determined by Western blotting. Changes in the phosphorylation status of protein kinase A (PKA), cAMP response element-binding protein (CREB), mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3-kinase (PI3K), serine/threonine kinase Akt, and glycogen kinase 3β (GSK3β) were also examined. The free radical scavenging activity of PCP increased in a dose-dependent manner. In PCP-treated B16F10 cells, transcript levels of glutathione peroxidase-1 (GPx-1) were increased compared with α-MSH-stimulated cells. In addition, PCP led to the down-regulation of phospho-p38, phospho-PKA, phospho-CREB, phospho-GSK3β, MITF, and TRP-1 compared with α-MSH-stimulated B16F10 cells. We believe this effect may be associated with PCP activity, which leads to the inhibition of melanin production and tyrosinase activity. These results suggest that PCP decreases tyrosinase activity and melanin production via inactivation of the p38 and PKA signaling pathways, and subsequently decreases phosphorylation of CREB, MITF, and melanogenic enzymes. These observations provided new insights on the molecular mechanisms of the skin-whitening property of PCP. PMID:26473849

  4. Silica nanoparticles induce cytokine responses in lung epithelial cells through activation of a p38/TACE/TGF-α/EGFR-pathway and NF-κΒ signalling

    SciTech Connect

    Skuland, Tonje Øvrevik, Johan; Låg, Marit; Schwarze, Per; Refsnes, Magne

    2014-08-15

    Amorphous silica nanoparticles (SiNPs) have previously been shown to induce marked cytokine (interleukin-6; IL-6 and interleukin-8; CXCL8/IL-8) responses independently of particle uptake in human bronchial epithelial BEAS-2B cells. In this study the involvement of the mitogen-activated protein kinases (MAP-kinases), nuclear factor-kappa Β (NF-κΒ) and in particular tumour necrosis factor-α converting enzyme (TACE) and—epidermal growth factor receptor (EGFR) signalling pathways were examined in triggering of IL-6 and CXCL8 release after exposure to a 50 nm silica nanoparticle (Si50). Exposure to Si50 increased phosphorylation of NF-κΒ p65 and MAP-kinases p38 and JUN-N-terminal protein kinase pathways (JNK), but not extracellular signal regulated kinases (ERK). Inhibition of NF-κΒ and p38 reduced the cytokine responses to Si50, whereas neither JNK- nor ERK-inhibition exerted any significant effect on the responses to Si50. Increases in membrane-bound transforming growth factor-α (TGF-α) release and EGFR phosphorylation were also observed after Si50 exposure, and pre-treatment with inhibitors of these pathways reduced the release of IL-6 and CXCL8, but did not affect the Si50-induced phosphorylation of p38 and p65. In contrast, p38-inhibition partially reduced Si50-induced TGF-α release, while the p65-inhibition was without effect. Overall, our results indicate that Si50-induced IL-6 and CXCL8 responses in BEAS-2B cells were regulated through combined activation of several pathways, including NF-κΒ and p38/TACE/TGF-α/EGFR signalling. The study identifies critical, initial events in the triggering of pro-inflammatory responses by nanoparticles. - Highlights: • Silica nanoparticles induce IL-6 and CXCL8 via NFκB and MAPKinase p38 in BEAS-2B • Silica nanoparticles induce release of the EGF-receptor ligand TGF-α • TGF-α release contributes to the IL-6 and CXCL8 release • Phosphorylation of p38 is involved in release of TGF-α.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  7. Si Shen Wan Inhibits mRNA Expression of Apoptosis-Related Molecules in p38 MAPK Signal Pathway in Mice with Colitis

    PubMed Central

    Zhao, Hai-Mei; Huang, Xiao-Ying; Zhou, Feng; Tong, Wen-Ting; Wan, Pan-Ting; Huang, Min-Fang; Ye, Qing; Liu, Duan-Yong

    2013-01-01

    Si Shen Wan (SSW) is used to effectively treat ulcerative colitis (UC) as a formula of traditional Chinese medicine. To explore the mechanism of SSW-inhibited apoptosis of colonic epithelial cell, the study observed mRNA expression of apoptosis-related molecules in p38 MAPK signal pathway in colonic mucosa in colitis mice treated with SSW. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in mice; meanwhile, the mice were administrated daily either SSW (5 g/kg) or p38 MAPK inhibitor (2 mg/kg) or vehicle (physiological saline) for 10 days. While microscopical evaluation was observed, apoptosis rate of colonic epithelial cell and mRNA expression of apoptosis-related molecules were tested. Compared with colitis mice without treatment, SSW alleviated colonic mucosal injuries and decreased apoptosis rate of colonic epithelial cell, while the mRNA expressions of p38 MAPK, p53, caspase-3, c-jun, c-fos, Bax, and TNF-α were decreased in the colonic mucosa in colitis mice treated with SSW, and Bcl-2 mRNA and the ratio of Bcl-2/Bax were increased. The present study demonstrated that SSW inhibited mRNA expression of apoptosis-related molecules in p38 MAPK signal pathway to downregulate colonic epithelial cells apoptosis in colonic mucosa in mice with colitis. PMID:24223057

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

    PubMed

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

    2016-06-01

    Titanium dioxide nanoparticles (TiO2 NPs) have been demonstrated to damage the kidneys. However, whether chronic nephritis leads to renal fibration or the fibrosis is associated with the activation of TGF-β/Smads/p38MAPK pathway caused by TiO2 NPs exposure is not well understood. Forty male mice were separately exposed to 0, 2.5, 5, or 10 mg/kg body weight TiO2 NPs for 6 months. Renal biochemical functions and levels of TGF-β/Smads/p38MAPK pathway-related markers and extracellular matrix (ECM) expression in the kidneys were investigated. The findings showed that subchronic TiO2 NPs exposure increased levels of urinary creatisix (Cr), N-acetyl-glucosaminidase, and vanin-1, resulted in severe renal inflammation and fibration. Furthermore, TiO2 NP exposure upregulated expression of transforming growth factor-β1 (TGF-β1, 0.07- to 2.72-fold), Smad2 (0.42- to 1.63-fold), Smad3 (0.02- to 1.94-fold), ECM (0.15- to 2.75-fold), α-smooth muscle actin (0.14- to 3.06-fold), p38 mitogen-activated protein kinase (p38MAPK, 0.11- to 3.78-fold), and nuclear factor-κB (0.4- to 2.27-fold), and downregulated Smad7 (0.05- to 0.61-fold) expression in mouse kidney. Subchronic TiO2 NPs exposure induced changes of renal characteristics towards inflammation and fibration may be mediated via TGF-β/Smads/p38MAPK pathway, and the uses of TiO2 NPs should be carried out cautiously, especially in humans. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1452-1461, 2016. PMID:26850371

  9. Transforming growth factor-β1 impairs CFTR-mediated anion secretion across cultured porcine vas deferens epithelial monolayer via the p38 MAPK pathway

    PubMed Central

    Yi, Sheng; Pierucci-Alves, Fernando

    2013-01-01

    The goal of this study was to determine whether transforming growth factor-β1 (TGF-β1) affects epithelial cells lining the vas deferens, an organ that is universally affected in cystic fibrosis male patients. In PVD9902 cells, which are derived from porcine vas deferens epithelium, TGF-β1 exposure significantly reduced short-circuit current (Isc) stimulated by forskolin or a cell membrane-permeant cAMP analog, 8-pCPT-cAMP, suggesting that TGF-β1 affects targets of the cAMP signaling pathway. Electrophysiological results indicated that TGF-β1 reduces the magnitude of current inhibited by cystic fibrosis transmembrane conductance regulator (CFTR) channel blockers. Real-time RT-PCR revealed that TGF-β1 downregulates the abundance of mRNA coding for CFTR, while biotinylation and Western blot showed that TGF-β1 reduces both total CFTR and apical cell surface CFTR abundance. These results suggest that TGF-β1 causes a reduction in CFTR expression, which limits CFTR-mediated anion secretion. TGF-β1-associated attenuation of anion secretion was abrogated by SB431542, a TGF-β1 receptor I inhibitor. Signaling pathway studies showed that the effect of TGF-β1 on Isc was reduced by SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK). TGF-β1 exposure also increased the amount of phospho-p38 MAPK substantially. In addition, anisomycin, a p38 MAPK activator, mimicked the effect of TGF-β1, which further suggests that TGF-β1 affects PVD9902 cells through a p38 MAPK pathway. These observations suggest that TGF-β1, via TGF-β1 receptor I and p38 MAPK signaling, reduces CFTR expression to impair CFTR-mediated anion secretion, which would likely compound the effects associated with mild CFTR mutations and ultimately would compromise male fertility. PMID:23903699

  10. Heat stress pretreatment decreases lipopolysaccharide-induced apoptosis via the p38 signaling pathway in human umbilical vein endothelial cells.

    PubMed

    Liu, Zhifeng; Zhong, Tianyu; Zheng, Dong; Cepinskas, Inga; Peng, Tianqing; Su, Lei

    2016-07-01

    The present study aimed to investigate vascular endothelial apoptosis, and the regulatory molecules involved in the condition of heatstroke caused by direct hyperthermia due to high core temperature and gut‑derived endotoxemia. Human umbilical vascular endothelial cells (HUVECs) were isolated and treated with heat stress (43˚C for 1 h), lipopolysaccharide (LPS; 1 µg/ml), or a combination of heat stress pretreatment followed by LPS. Caspase‑3 activity, DNA fragmentation, and cell viability, determined using a 3‑(4, 5‑dimethyl thiazol‑2‑yl)‑2,5‑diphenyl tetrazolium bromide assay, were measured to examine cellular apoptosis. Changes in the expression levels of heat shock protein (HSP) 27, HSP90 and B‑cell lymphoma 2 (Bcl‑2), and the phosphorylation of p38 were detected using Western blot assays. The specific inhibitor of p38, SB203580, was also used. LPS induced endothelial apoptosis, as indicated by increased caspase‑3 activity, a high level of DNA fragmentation and low cell viability. LPS also increased p38 phosphorylation and decreased the expression levels of HSP27, HSP90 and Bcl‑2. Heat stress pretreatment inhibited LPS‑induced cellular apoptosis, increased the phosphorylation of p38, and increased the expression levels of HSP27, HSP90 and Bcl‑2. Pretreatment with SB203580 had effects similar to those of heat stress in the amelioration of LPS‑induced effects. These findings demonstrated that heat stress pretreatment decreased LPS‑induced Bcl‑2‑associated apoptosis in HUVECs by attenuating p38 activation, thereby increasing the expression levels of HSP27 and HSP90. PMID:27222013

  11. B-Myb switches from Cyclin/Cdk-dependent to Jnk- and p38 kinase-dependent phosphorylation and associates with SC35 bodies after UV stress

    PubMed Central

    Werwein, E; Dzuganova, M; Usadel, C; Klempnauer, K-H

    2013-01-01

    B-Myb is a highly conserved member of the Myb transcription factor family that has essential roles in cell-cycle progression. Recent work has suggested that B-Myb is also involved in the cellular DNA-damage response. Here, we have investigated the fate of B-Myb in UV-irradiated cells. UV stress leads to the appearance of phosphorylated B-Myb in nuclear SC35 speckles during transcriptional shutdown. Furthermore, we show that UV irradiation leads to a change of the phosphorylation pattern of B-Myb, which is caused by a switch from Cyclin/Cdk-dependent to Jnk and p38 kinase-dependent phosphorylation. Taken together, we have identified Jnk and p38 kinase as novel regulators of B-Myb and established the localization of phosphorylated B-Myb in SC35 speckles as a potential novel regulatory mechanism for B-Myb in UV irradiated cells. PMID:23449447

  12. Effect of training on activation of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase pathways in rat soleus muscle.

    PubMed

    Lee, Jong Sam; Bruce, Clinton R; Spurrell, Brian E; Hawley, John A

    2002-08-01

    1. The effect of a chronic programme of either low- or moderate-to-high-intensity treadmill running on the activation of the extracellular-signal regulated protein kinase (ERK1/2) and the p38 mitogen-activated protein kinase (MAPK) pathways was determined in rat muscle. 2. Sprague-Dawley rats were assigned to one of three groups: (i) sedentary (NT; n = 8); (ii) low-intensity training (8 m/min; LIT; n = 16); and (iii) moderate-to-high-intensity training (28 m/min; HIT; n = 16). The training regimens were planned so that animals covered the same distance and had similar glycogen utilization for both LIT and HIT exercise sessions. 3. A single bout of LIT or HIT following 8 weeks of training led to a twofold increase in the phosphorylation of ERK1/2 (P = 0.048) and a two- to threefold increase in p38 MAPK (P = 0.005). Extracellular signal-regulated kinase 1/2 phosphorylation in muscle sampled 48 h after the last exercise bout was similar to sedentary values, while p38 MAPK phosphorylation was 70-80% lower than sedentary. One bout of LIT or HIT increased total ERK1/2 and p38 MAPK expression, with the magnitude of this increase being independent of prior exercise intensity or duration. Extracellular signal- regulated kinase 1/2 expression was increased three- to fourfold in muscle sampled 48 h after the last exercise bout irrespective of the prior training programme (P = 0.027), but p38 MAPK expression was approximately 90% lower than sedentary values. 4. In conclusion, exercise-training of different intensities/ durations results in selective postexercise activation of intracellular signalling pathways, which may be one mechanism regulating specific adaptations induced by diverse training programmes. PMID:12099995

  13. BMP4 Increases Canonical Transient Receptor Potential Protein Expression by Activating p38 MAPK and ERK1/2 Signaling Pathways in Pulmonary Arterial Smooth Muscle Cells

    PubMed Central

    Li, Xiaoyan; Lu, Wenju; Fu, Xin; Zhang, Yi; Yang, Kai; Zhong, Nanshan; Ran, Pixin

    2013-01-01

    Abnormal bone morphogenetic protein (BMP) signaling has been implicated in the pathogenesis of pulmonary hypertension. We previously found that BMP4 elevated basal intracellular Ca2+ ([Ca2+]i) concentrations in distal pulmonary arterial smooth muscle cells (PASMCs), attributable in large part to enhanced store-operated Ca2+ entry through store-operated Ca2+ channels (SOCCs). Moreover, BMP4 up-regulated the expression of canonical transient receptor potential (TRPC) proteins thought to compose SOCCs. The present study investigated the signaling pathways through which BMP4 regulates TRPC expression and basal [Ca2+]i in distal PASMCs. Real-time quantitative PCR was used for the measurement of mRNA, Western blotting was used for the measurement of protein, and fluorescent microscopic for [Ca2+]i was used to determine the involvement of p38 and extracellular regulated kinase (ERK)–1/2 mitogen-activated protein kinase (MAPK) signaling in BMP4–induced TRPC expression and the elevation of [Ca2+]i in PASMCs. We found that the treatment of BMP4 led to the activation of both p38 MAPK and ERK1/2 in rat distal PASMCs. The induction of TRPC1, TRPC4, and TRPC6 expression, and the increases of [Ca2+]i caused by BMP4 in distal PASMCs, were inhibited by treatment with either SB203580 (10 μM), the selective inhibitor for p38 activation, or the specific p38 small interfering RNA (siRNA). Similarly, those responses induced by BMP4 were also abolished by treatment with PD98059 (5 μM), the selective inhibitor of ERK1/2, or by the knockdown of ERK1/2 using its specific siRNA. These results indicate that BMP4 participates in the regulation of Ca2+ signaling in PASMCs by modulating TRPC channel expression via activating p38 and ERK1/2 MAPK pathways. PMID:23526217

  14. The Apoptotic Effect of Ursolic Acid on SK-Hep-1 Cells is Regulated by the PI3K/Akt, p38 and JNK MAPK Signaling Pathways.

    PubMed

    Chuang, Wan-Ling; Lin, Ping-Yi; Lin, Hui-Chuan; Chen, Yao-Li

    2016-01-01

    Ursolic acid (UA) is a pentacyclic triterpene acid that is present in a wide variety of medicinal herbs and edible plants. This study investigated the effect of UA on apoptosis and proliferation of hepatocellular carcinoma SK-Hep-1 cells. After treatment of SK-Hep-1 cells with different concentrations of UA, we observed that cell viability was reduced in a dose- and time-dependent manner. Furthermore, there was a dose-dependent increase in the percentage of cells in the sub-G1 and G2/M phases, with cells treated with 60 μM showing the highest percentages of cells in those phases. UA-induced chromatin condensation of nuclei was observed by using DAPI staining. The western blot results revealed that exposure to UA was associated with decreased expression of the anti-apoptotic proteins Mcl-1, Bcl-xL, Bcl-2, and TCTP and increased expression of apoptosis-related proteins TNF-α, Fas, FADD, Bax, cleaved caspase-3, caspase-8, caspase-9, and PARP. Immunocytochemistry staining showed that treatment with UA resulted in increased expression of caspase-3. Moreover, exposure to UA resulted in the inhibition of the PI3K/Akt and p38 MAPK signaling pathways. These findings suggest that UA inhibits the proliferation of SK-Hep-1 cells and induces apoptosis. PMID:27104510

  15. Loss of CAR promotes migration and proliferation of HaCaT cells, and accelerates wound healing in rats via Src-p38 MAPK pathway

    PubMed Central

    Su, Linlin; Fu, Lanqing; Li, Xiaodong; Zhang, Yue; Li, Zhenzhen; Wu, Xue; Li, Yan; Bai, Xiaozhi; Hu, Dahai

    2016-01-01

    The coxsackie and adenovirus receptor (CAR) is a cell adhesion molecule mostly localized to cell-cell contacts in epithelial and endothelial cells. CAR is known to regulate tumor progression, however, its physiological role in keratinocyte migration and proliferation, two essential steps in re-epithelialization during wound healing, has less been investigated. Here we showed that CAR was predominantly expressed in the epidermis of human skin, CAR knockdown by RNAi significantly accelerated HaCaT cell migration and proliferation. In addition, knockdown of CAR in vitro increased p-Src, p-p38, and p-JNK protein levels; however, Src inhibitor PP2 prevented the increase of p-Src and p-p38 induced by CAR RNAi, but not p-JNK, and decelerated cell migration and proliferation. More intriguingly, in vivo CAR RNAi on the skin area surrounding the wounds on rat back visually accelerated wound healing and re-epithelialization process, while treatment with PP2 or p38 inhibitor SB203580 obviously inhibited these effects. By contrast, overexpressing CAR in HaCaT cells significantly decelerated cell migration and proliferation. Above results demonstrate that suppression of CAR could accelerate HaCaT cell migration and proliferation, and promote wound healing in rat skin, probably via Src-p38 MAPK pathway. CAR thus might serve as a novel therapeutic target for facilitating wound healing. PMID:26804208

  16. Selective suppression of Notch1 inhibits proliferation of renal cell carcinoma cells through JNK/p38 pathway.

    PubMed

    Wu, Kerong; Hu, Linkun; Hou, Jianquan

    2016-05-01

    The present study was performed to explore the effects of Notch1 inhibition selectively by siRNA on the proliferation and cell cycle of renal carcinoma cells. Human renal carcinoma cell lines, 786-0 and Caki-1, were treated with Si-Notch1 or negative control (NC). RT-PCR and western blotting were used to confirm the efficiency of siRNA on Notch1 expression. MTT, cell cycle analysis, colony formation as well as migration and invasion assays were performed. The expression levels of p38 and SAPK/JNK were measured by western blotting. For both cell lines, as compared with the NC group, the cell growth was markedly reduced, and colony formation was restricted in the Si-Notch1‑treated group. After incubated with Si-Notch1 or NC for 48 h, Si-Notch1-treated cells arrested the cell cycle at G1/S phase. The Si-Notch1 group also had a reduced rate of migration as well as invasion. Moreover, we observed a reduction in p-SAPK/JNK and p-p38 in Si-Notch1 transfected cells. The present study indicated that Notch signaling is important in the tumorigenesis of renal cell carcinoma. Notch1 may be a potential therapeutic regimen towards renal cell carcinoma, and JNK/p38 may serve as an important molecular mechanism for Notch1-mediated carcinogenesis. PMID:26986634

  17. NF-κB-dependent microRNA-125b up-regulation promotes cell survival by targeting p38α upon ultraviolet radiation.

    PubMed

    Tan, Guangyun; Niu, Jixiao; Shi, Yuling; Ouyang, Hongsheng; Wu, Zhao-Hui

    2012-09-21

    UV-induced stress response involves expression change of a myriad of genes, which play critical roles in modulating cell cycle arrest, DNA repair, and cell survival. Alteration of microRNAs has been found in cells exposed to UV, yet their function in UV stress response remains elusive. Here, we show that UV radiation induces up-regulation of miR-125b, which negatively regulates p38α expression through targeting its 3'-UTR. Increase of miR-125b depends on UV-induced NF-κB activation, which enhances miR-125b gene transcription upon UV radiation. The DNA damage-responsive kinase ATM (ataxia telangiectasia mutated) is indispensable for UV-induced NF-κB activation, which may regulate p38α activation and IKKβ-dependent IκBα degradation in response to UV. Consequently, repression of p38α by miR-125b prohibits prolonged hyperactivation of p38α by UV radiation, which is required for protecting cells from UV-induced apoptosis. Altogether, our data support a critical role of NF-κB-dependent up-regulation of miR-125b, which forms a negative feedback loop to repress p38α activation and promote cell survival upon UV radiation. PMID:22854965

  18. Angiopoietin-Like Protein 7 Promotes an Inflammatory Phenotype in RAW264.7 Macrophages Through the P38 MAPK Signaling Pathway.

    PubMed

    Qian, Tao; Wang, Kun; Cui, Jiesheng; He, Yiduo; Yang, Zaiqing

    2016-06-01

    Angiopoietin-like protein 7 (Angptl7) has been extensively studied for decades, but its potential immune functions have not been characterized. Hence, we investigated the relationship between Angptl7 and inflammation by using RAW264.7 monocyte/macrophage cells. The expression of genes encoding inflammation-associated factors cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, IL-10, and transforming growth factor beta 1 (TGF-β1)) decreased after RAW264.7 cells were treated with anti-Angptl7 polyclonal antibody but increased after the cells were transfected with an Angptl7-expressing plasmid. Angptl7 overexpression enhanced phagocytosis and inhibited the proliferation of RAW264.7 cells. In addition, Angptl7 antagonized the anti-inflammatory effects of TGF-β1 and dexamethasone. Pathway analysis showed that Angptl7 promoted the phosphorylation of both p65 and p38, but only the P38 mitogen-activated protein kinase (MAPK) signaling pathway mediated Angptl7-associated inflammatory functions. Additionally, after 1 week of daily intraperitoneal injections of recombinant TNF-α in a mouse model of peripheral inflammation, Angptl7 expression increased in the mouse eyes. Thus, Angptl7 is a factor that promotes pro-inflammatory responses in macrophages through the P38 MAPK signaling pathway and represents a potential therapeutic target for treatment of inflammatory diseases. PMID:26973239

  19. Regulation of a DLK-1 and p38 MAP kinase pathway by the ubiquitin ligase RPM-1 is required for presynaptic development.

    PubMed

    Nakata, Katsunori; Abrams, Benjamin; Grill, Brock; Goncharov, Alexandr; Huang, Xun; Chisholm, Andrew D; Jin, Yishi

    2005-02-11

    Synapses display a stereotyped ultrastructural organization, commonly containing a single electron-dense presynaptic density surrounded by a cluster of synaptic vesicles. The mechanism controlling subsynaptic proportion is not understood. Loss of function in the C. elegans rpm-1 gene, a putative RING finger/E3 ubiquitin ligase, causes disorganized presynaptic cytoarchitecture. RPM-1 is localized to the presynaptic periactive zone. We report that RPM-1 negatively regulates a p38 MAP kinase pathway composed of the dual leucine zipper-bearing MAPKKK DLK-1, the MAPKK MKK-4, and the p38 MAP kinase PMK-3. Inactivation of this pathway suppresses rpm-1 loss of function phenotypes, whereas overexpression or constitutive activation of this pathway causes synaptic defects resembling rpm-1(lf) mutants. DLK-1, like RPM-1, is localized to the periactive zone. DLK-1 protein levels are elevated in rpm-1 mutants. The RPM-1 RING finger can stimulate ubiquitination of DLK-1. Our data reveal a presynaptic role of a previously unknown p38 MAP kinase cascade. PMID:15707898

  20. Effects of physical exercise on the P38MAPK/REDD1/14-3-3 pathways in the myocardium of diet-induced obesity rats.

    PubMed

    Pieri, B L S; Souza, D R; Luciano, T F; Marques, S O; Pauli, J R; Silva, A S R; Ropelle, E R; Pinho, R A; Lira, F S; De Souza, C T

    2014-08-01

    Obesity is associated with myocardial insulin resistance and impairment of the mammalian target of rapamycin (mTOR) signaling pathway. The activation of the mTOR cascade by exercise has been largely shown in skeletal muscle, but insufficiently analyzed in myocardial tissue. In addition, little is known regarding the mTOR upstream molecules in the hearts of obese animals and even less about the role of exercise in this process. Thus, the present study was aimed to evaluate the effects of physical exercise on P38 Mitogen-Activated Protein Kinase (P38MAPK) phosphorylation and the REDD1 (regulated in development and DNA damage responses 1) and 14-3-3 protein levels in the myocardium of diet-induced obesity (DIO) rats. After achievement of DIO and insulin resistance, Wistar rats were divided in 2 groups: sedentary obese rats and obese rats performed treadmill running (50-min/day, 5 days per week velocity of 1.0 km/h for 2 months). Forty-eight hours after the final physical exercise, the rats were killed, and the myocardial tissue was removed for Western blot analysis. DIO increased the REDD1 protein levels and reduced the 14-3-3 protein levels and P38MAPK, mTOR, P70S6k (p70 ribosomal S6 protein kinase), and 4EBP1 (4E-binding protein-1) phosphorylation. Interestingly, physical exercise reduced the REDD1 protein levels and increased the 14-3-3 protein levels and P38MAPK, mTOR, P70S6k, and 4EBP1 phosphorylation. Moreover, exercise increased the REDD1/14-3-3 association in the heart. Our results indicate that the phospho-P38MAPK, REDD1, and 14-3-3 protein levels were reduced in the myocardium of obese rats and that physical exercise increased the protein levels of these molecules. PMID:24691733

  1. Baicalin ameliorates isoproterenol-induced acute myocardial infarction through iNOS, inflammation, oxidative stress and P38MAPK pathway in rat

    PubMed Central

    Sun, Shen-Jie; Wu, Xiao-Peng; Song, Heng-Liang; Li, Gui-Qi

    2015-01-01

    Baicalin is one of the active ingredients in the skullcap, with a variety of pharmacological effects, such as blood pressure reduction, sedation, liver-protection, gallbladder-protection, anti-bacteria, anti-inflammation, etc. The aim of this study was to investigate the potential cardioprotective effects of baicalin ameliorates isoproterenol-induced acute myocardial infarction (AMI) through inducible nitric oxide synthase (iNOS), inflammation, oxidative stress and P38MAPK passageway in rat. Rat model of AMI was induced by isoproterenol (100 mg/kg) and then treated baicalin (various does of baicalin: 1 mg/kg, 10 mg/kg and 100 mg/kg, respectively) for 24 h. Infarct size, the heart weight to body weight ratio and creatine kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) of rats with AMI induced by isoproterenol were used to evaluate curative effect of baicalin on AMI. Meanwhile, iNOS and phosphorylation-p38 MAPK (p-p38) protein expressions, inflammatory factor and oxidative stress were inspected using western blot and commercial kits, respectively. In the present study, pre-treatment with baicalin (10 or 100 mg/kg) significantly ameliorated infarct size, the heart weight to body weight ratio and CK, CK-MB, LDH and cTnT levels in rats with AMI induced by isoproterenol. iNOS protein expression, the serum TNF-α, IL-6, MDA and SOD levels and p-38 protein expressions were significantly suppressed by treatment with baicalin (10 or 100 mg/kg). These results suggest that acute treatment with baicalin ameliorates AMI, iNOS, inflammation, oxidative stress and P38MAPK pathway in rat with AMI induced by isoproterenol. PMID:26885181

  2. The p38 mitogen-activated protein kinase signaling pathway is involved in regulating low-density lipoprotein receptor-related protein 1-mediated β-amyloid protein internalization in mouse brain.

    PubMed

    Ma, Kai-Ge; Lv, Jia; Hu, Xiao-Dan; Shi, Li-Li; Chang, Ke-Wei; Chen, Xin-Lin; Qian, Yi-Hua; Yang, Wei-Na; Qu, Qiu-Min

    2016-07-01

    Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Recently, increasing evidence suggests that intracellular β-amyloid protein (Aβ) alone plays a pivotal role in the progression of AD. Therefore, understanding the signaling pathway and proteins that control Aβ internalization may provide new insight for regulating Aβ levels. In the present study, the regulation of Aβ internalization by p38 mitogen-activated protein kinases (MAPK) through low-density lipoprotein receptor-related protein 1 (LRP1) was analyzed in vivo. The data derived from this investigation revealed that Aβ1-42 were internalized by neurons and astrocytes in mouse brain, and were largely deposited in mitochondria and lysosomes, with some also being found in the endoplasmic reticulum. Aβ1-42-LRP1 complex was formed during Aβ1-42 internalization, and the p38 MAPK signaling pathway was activated by Aβ1-42 via LRP1. Aβ1-42 and LRP1 were co- localized in the cells of parietal cortex and hippocampus. Furthermore, the level of LRP1-mRNA and LRP1 protein involved in Aβ1-42 internalization in mouse brain. The results of this investigation demonstrated that Aβ1-42 induced an LRP1-dependent pathway that related to the activation of p38 MAPK resulting in internalization of Aβ1-42. These results provide evidence supporting a key role for the p38 MAPK signaling pathway which is involved in the regulation of Aβ1-42 internalization in the parietal cortex and hippocampus of mouse through LRP1 in vivo. PMID:27163530

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

    PubMed Central

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

    2014-01-01

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

  4. Oridonin induces apoptosis in SW1990 pancreatic cancer cells via p53- and caspase-dependent induction of p38 MAPK.

    PubMed

    Bu, He-Qi; Liu, Dian-Lei; Wei, Wei-Tian; Chen, Liang; Huang, Hai; Li, Ye; Cui, Jun-Hui

    2014-02-01

    Oridonin, an active component isolated from Rabdosia rubescens, has been reported to exhibit antitumor effects. In the present study, we evaluated the antitumor activity and the mechanisms of action of oridonin in pancreatic cancer. Oridonin treatment significantly induced apoptotic cell death in SW1990 pancreatic cancer cells in a dose-dependent manner. Additionally, cell apoptosis was markedly inhibited by PFT α (pifithrin α), a p53-specific inhibitor, which was applied to evaluate the function of p53, showing that p53 was responsible for the cytotoxity of oridonin. Moreover, oridonin increased the expression of p-p53 with a concomitant increase in p21 in the SW1990 cells. Following treatment with mitogen-activated protein kinase (MAPK) inhibitors, PD98059 (ERK inhibitor), SP600125 (JNK inhibitor) and SB203580 (p38 inhibitor), the cytotoxity of oridonin was not influenced by JNK (SP600125) and ERK (PD98059), but these effects were opposite to the cytotoxity of oridonin observed with SP203580 treatment. These findings confirmed that orodonin-induced apoptosis was p38-dependent, but JNK- and ERK-independent. Furthermore, the activation of the p38 kinase promoted the activation of p53 and its downstream target p21, and further caused caspase-9 and -3 activation, as demonstrated by evidence showing that the p38 inhibitor SB203580 not only blocked the phosphorylation of p38 but also reduced the activation of p53, p21 and caspase-9 and -3. Collectively, these results suggest that p53-dependent and caspase-dependent induction of p38 MAPK directly participates in apoptosis induced by oridonin. PMID:24297112

  5. Paroxetine-induced apoptosis in human osteosarcoma cells: Activation of p38 MAP kinase and caspase-3 pathways without involvement of [Ca{sup 2+}]{sub i} elevation

    SciTech Connect

    Chou, C.-T.; He Shiping; Jan, C.-R. . E-mail: crjan@isca.vghks.gov.tw

    2007-02-01

    Selective serotonin reuptake inhibitors (SSRIs), a group of antidepressants, are generally used for treatment of various mood and anxiety disorders. There has been much research showing the anti-tumor and cytotoxic activities of some antidepressants; but the detailed mechanisms were unclear. In cultured human osteosarcoma cells (MG63), paroxetine reduced cell viability in a concentration- and time-dependent manner. Paroxetine caused apoptosis as assessed by propidium iodide-stained cells and increased caspase-3 activation. Although immunoblotting data revealed that paroxetine could activate the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun NH{sub 2}-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK), only SB203580 (a p38 MAPK inhibitor) partially prevented cells from apoptosis. Paroxetine also induced [Ca{sup 2+}]{sub i} increases which involved the mobilization of intracellular Ca{sup 2+} stored in the endoplasmic reticulum and Ca{sup 2+} influx from extracellular medium. However, pretreatment with BAPTA/AM, a Ca{sup 2+} chelator, to prevent paroxetine-induced [Ca{sup 2+}]{sub i} increases did not protect cells from death. The results suggest that in MG63 cells, paroxetine caused Ca{sup 2+}-independent apoptosis via inducing p38 MAPK-associated caspase-3 activation.

  6. HMG-CoA reductase inhibitors induce apoptosis of lymphoma cells by promoting ROS generation and regulating Akt, Erk and p38 signals via suppression of mevalonate pathway

    PubMed Central

    Qi, X-F; Zheng, L; Lee, K-J; Kim, D-H; Kim, C-S; Cai, D-Q; Wu, Z; Qin, J-W; Yu, Y-H; Kim, S-K

    2013-01-01

    Statins, the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are widely used cholesterol-lowering drugs. Convincing evidence indicates that statins stimulate apoptotic cell death in several types of proliferating tumor cells in a cholesterol-lowering-independent manner. The objective here was to elucidate the molecular mechanism by which statins induce lymphoma cells death. Statins (atorvastatin, fluvastatin and simvastatin) treatment enhanced the DNA fragmentation and the activation of proapoptotic members such as caspase-3, PARP and Bax, but suppressed the activation of anti-apoptotic molecule Bcl-2 in lymphoma cells including A20 and EL4 cells, which was accompanied by inhibition of cell survival. Both increase in levels of reactive oxygen species (ROS) and activation of p38 MAPK and decrease in mitochondrial membrane potential and activation of Akt and Erk pathways were observed in statin-treated lymphoma cells. Statin-induced cytotoxic effects, DNA fragmentation and changes of activation of caspase-3, Akt, Erk and p38 were blocked by antioxidant (N-acetylcysteine) and metabolic products of the HMG-CoA reductase reaction, such as mevalonate, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). These results suggests that HMG-CoA reductase inhibitors induce lymphoma cells apoptosis by increasing intracellular ROS generation and p38 activation and suppressing activation of Akt and Erk pathways, through inhibition of metabolic products of the HMG-CoA reductase reaction including mevalonate, FPP and GGPP. PMID:23449454

  7. A diacylglycerol kinase inhibitor, R59022, stimulates glucose transport through a MKK3/6-p38 signaling pathway in skeletal muscle cells.

    PubMed

    Takahashi, Nobuhiko; Nagamine, Miho; Tanno, Satoshi; Motomura, Wataru; Kohgo, Yutaka; Okumura, Toshikatsu

    2007-08-17

    Diacylglycerol kinase (DGK) is one of lipid-regulating enzymes, catalyzes phosphorylation of diacylglycerol to phosphatidic acid. Because skeletal muscle, a major insulin-target organ for glucose disposal, expresses DGK, we investigated in the present study a role of DGK on glucose transport in skeletal muscle cells. PCR study showed that C2C12 myotubes expressed DGKalpha, delta, epsilon, zeta, or theta isoform mRNA. R59022, a specific inhibitor of DGK, significantly increased glucose transport, p38 and MKK3/6 activation in C2C12 myotubes. The R59022-induced glucose transport was blocked by SB203580, a specific p38 inhibitor. In contrast, R59022 failed to stimulate both possible known mechanisms to enhance glucose transport, an IRS1-PI3K-Akt pathway, muscle contraction signaling or GLUT1 and 4 expression. All these results suggest that DGK may play a role in glucose transport in the skeletal muscle cells through modulating a MKK3/6-p38 signaling pathway. PMID:17588539

  8. Protective effects of protocatechuic acid on acute lung injury induced by lipopolysaccharide in mice via p38MAPK and NF-κB signal pathways.

    PubMed

    Zhang, Xiuli; Li, Chunli; Li, Jun; Xu, Yingzhen; Guan, Shui; Zhao, Mingshan

    2015-05-01

    The study aims to investigate the effects of protocatechuic acid (PCA) separated from Chinese herbs, on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in mice. The mouse model was induced by intraperitoneal injection of LPS at the dose of 5mg/kg body weight. Three doses of PCA (30, 15, 5 mg/kg) were administered to mice with intraperitoneal injection one hour prior to LPS exposure. Six hours later after LPS administration, the effect of PCA on ALI mice was assessed via histopathological examination by HE staining, inflammatory cytokine production by ELISA assay and RT-PCR, p38MAPK and NF-κB activation by Western blot analysis. We found that PCA administration significantly ameliorated lung histopathological changes and decreased protein concentration in the bronchoalveolar lavage fluid. Furthermore, the overproduction of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) was reduced by PCA. Additionally, PCA at the dose of 30 mg/kg could block the activation of p38MAPK and NF-κB signal pathways induced by LPS. In conclusion, our findings demonstrate that PCA possesses a protective effect on LPS-induced ALI in mice via suppression of p38MAPK and NF-κB signal pathways. Therefore, PCA may be useful in the therapy of lung inflammatory diseases, especially for ALI. PMID:25841318

  9. Interleukin-17A Promotes Aortic Endothelial Cell Activation via Transcriptionally and Post-translationally Activating p38 Mitogen-activated Protein Kinase (MAPK) Pathway.

    PubMed

    Mai, Jietang; Nanayakkara, Gayani; Lopez-Pastrana, Jahaira; Li, Xinyuan; Li, Ya-Feng; Wang, Xin; Song, Ai; Virtue, Anthony; Shao, Ying; Shan, Huimin; Liu, Fang; Autieri, Michael V; Kunapuli, Satya P; Iwakura, Yoichiro; Jiang, Xiaohua; Wang, Hong; Yang, Xiao-Feng

    2016-03-01

    Interleukin-17 (IL-17)-secreting T helper 17 cells were recently identified as a CD4(+) T helper subset and implicated in various inflammatory and autoimmune diseases. The issues of whether and by what mechanism hyperlipidemic stress induces IL-17A to activate aortic endothelial cells (ECs) and enhance monocyte adhesion remained largely unknown. Using biochemical, immunological, microarray, experimental data mining analysis, and pathological approaches focused on primary human and mouse aortic ECs (HAECs and MAECs) and our newly generated apolipoprotein E (ApoE)(-/-)/IL-17A(-/-) mice, we report the following new findings. 1) The hyperlipidemia stimulus oxidized low density lipoprotein up-regulated IL-17 receptor(s) in HAECs and MAECs. 2) IL-17A activated HAECs and increased human monocyte adhesion in vitro. 3) A deficiency of IL-17A reduced leukocyte adhesion to endothelium in vivo. 3) IL-17A activated HAECs and MAECs via up-regulation of proinflammatory cytokines IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), chemokine CXC motif ligand 1 (CXCL1), and CXCL2. 4) IL-17A activated ECs specifically via the p38 mitogen-activated protein kinases (MAPK) pathway; the inhibition of p38 MAPK in ECs attenuated IL-17A-mediated activation by ameliorating the expression of the aforementioned proinflammatory cytokines, chemokines, and EC adhesion molecules including intercellular adhesion molecule 1. Taken together, our results demonstrate for the first time that IL-17A activates aortic ECs specifically via p38 MAPK pathway. PMID:26733204

  10. CX3CL1/CX3CR1 Axis Plays a Key Role in Ischemia-Induced Oligodendrocyte Injury via p38MAPK Signaling Pathway.

    PubMed

    Wu, Xiao-Mei; Liu, Yong; Qian, Zhong-Ming; Luo, Qian-Qian; Ke, Ya

    2016-08-01

    Based on current knowledge on the role of the CX3CL1/CX3CR1 axis in the regulation of microglial activation and on the involvement of activated microglia in damaging oligodendrocytes, we hypothesized that CX3CL1/CX3CR1 axis is associated with the development of ischemic oligodendrocyte and white matter injury. We investigated the effects of CX3CL1, CX3CR1 shRNA, and p38MAPK inhibitor on the apoptosis, proliferation, and myelin proteolipid protein (PLP) expression in oligodendrocytes in co-cultures with BV2 microglia under ischemia. We demonstrated that CX3CL1 markedly increased the numbers of apoptotic oligodendrocytes, decreased PLP expression in oligodendrocytes, and inhibited the increased proliferation of oligodendrocytes induced by ischemia in co-cultures. All these effects of CX3CL1 were suppressed by pre-treatment of BV2 microglia with CX3CR1 shRNA to silence CX3CR1 expression or SB203580 to inhibit p38MAPK pathway. Our findings support that CX3CL1/CX3CR1 axis plays a key role in the development of ischemia-induced oligodendrocyte injury via p38MAPK signaling pathway. PMID:26189830

  11. Osthole-mediated cell differentiation through bone morphogenetic protein-2/p38 and extracellular signal-regulated kinase 1/2 pathway in human osteoblast cells.

    PubMed

    Kuo, Po-Lin; Hsu, Ya-Ling; Chang, Cheng-Hsiung; Chang, Jiunn-Kae

    2005-09-01

    The survival of osteoblast cells is one of the determinants of the development of osteoporosis in patients. Osthole (7-methoxy-8-isopentenoxycoumarin) is a coumarin derivative present in many medicinal plants. By means of alkaline phosphatase (ALP) activity, osteocalcin, osteopontin, and type I collagen, enzyme-linked immunosorbent assay, we have shown that osthole exhibits a significant induction of differentiation in two human osteoblast-like cell lines, MG-63 and hFOB. Induction of differentiation by osthole was associated with increased bone morphogenetic protein (BMP)-2 production and the activations of SMAD1/5/8 and p38 and extracellular signal-regulated kinase (ERK) 1/2 kinases. Addition of purified BMP-2 protein did not increase the up-regulation of ALP activity and osteocalcin by osthole, whereas the BMP-2 antagonist noggin blocked both osthole and BMP-2-mediated ALP activity enhancement, indicating that BMP-2 production is required in osthole-mediated osteoblast maturation. Pretreatment of osteoblast cells with noggin abrogated p38 activation but only partially decreased ERK1/2 activation, suggesting that BMP-2 signaling is required in p38 activation and is partially involved in ERK1/2 activation in osthole-treated osteoblast cells. Cotreatment of p38 inhibitor SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole] or p38 small interfering RNA (siRNA) expression inhibited osthole-mediated activation of ALP but only slightly affected osteocalcin production. In contrast, the production of osteocalcin induced by osthole was inhibited by the mitogen-activated protein kinase kinase inhibitor PD98059 (2'-amino-3'-methoxyflavone) or by expression of an ERK2 siRNA. These data suggest that BMP-2/p38 pathway links to the early phase, whereas ERK1/2 pathway is associated with the later phase in osthole-mediated differentiation of osteoblast cells. In this study, we demonstrate that osthole is a promising agent for treating osteoporosis

  12. Prp19 facilitates invasion of hepatocellular carcinoma via p38 mitogen-activated protein kinase/Twist1 pathway

    PubMed Central

    Zhu, Ji-Min; Yu, Qian; Xue, Ru-Yi; Fang, Ying; Zhang, Yi-An; Chen, Yan-Jie; Liu, Tao-Tao; Dong, Ling; Shen, Xi-Zhong

    2016-01-01

    Pre-mRNA processing factor 19 (Prp19) is involved in many cellular events including pre-mRNA processing and DNA damage response. However, the pathological role of Prp19 in hepatocellular carcinoma (HCC) is still elusive. Here, we reported that Prp19 was increased in most HCC tissues and HCC cell lines, and its overexpression in HCC tissues was positively correlated with vascular invasion, tumor capsule breakthrough and poor prognosis. Prp19 potentiated migratory and invasive abilities of HCC cells in vitro and in vivo. Furthermore Prp19 facilitated Twist1-induced epithelial-mesenchymal transition. Mechanistic insights revealed that Prp19 directly binded with TGF-β-activated kinase1 (TAK1) and promoted the activation of p38 mitogen-activated protein kinase (MAPK), preventing Twist1 from degradation. Finally Prp19/p38 MAPK/Twist1 axis was attested in nude mice xenografts and HCC patient specimens. This work implies that the gain of Prp19 is a critical event during the progression of HCC, making it a promising target for malignancies with aberrant Prp19 expression. PMID:26959880

  13. Diarachidonoylphosphoethanolamine induces apoptosis of malignant pleural mesothelioma cells through a Trx/ASK1/p38 MAPK pathway.

    PubMed

    Tsuchiya, Ayako; Kaku, Yoshiko; Nakano, Takashi; Nishizaki, Tomoyuki

    2015-11-01

    1,2-Diarachidonoyl-sn-glycero-3-phosphoethanolamine (DAPE) induces both necrosis/necroptosis and apoptosis of NCI-H28 malignant pleural mesothelioma (MPM) cells. The present study was conducted to understand the mechanism for DAPE-induced apoptosis of NCI-H28 cells. DAPE induced caspase-independent apoptosis of NCI-H28 malignant pleural mesothelioma (MPM) cells, and the effect of DAPE was prevented by antioxidants or an inhibitor of NADPH oxidase (NOX). DAPE generated reactive oxygen species (ROS) and inhibited activity of thioredoxin (Trx) reductase (TrxR). DAPE decreased an association of apoptosis signal-regulating kinase 1 (ASK1) with thioredoxin (Trx), thereby releasing ASK1. DAPE activated p38 mitogen-activated protein kinase (MAPK), which was inhibited by an antioxidant or knocking-down ASK1. In addition, DAPE-induced NCI-H28 cell death was also prevented by knocking-down ASK1. Taken together, the results of the present study indicate that DAPE stimulates NOX-mediated ROS production and suppresses TrxR activity, resulting in the decrease of reduced Trx and the dissociation of ASK1 from a complex with Trx, allowing sequential activation of ASK1 and p38 MAPK, to induce apoptosis of NCI-H28 MPM cells. PMID:26588871

  14. Heat shock up-regulates expression of Toll-like receptor-2 and Toll-like receptor-4 in human monocytes via p38 kinase signal pathway

    PubMed Central

    Zhou, Jun; An, Huazhang; Xu, Hongmei; Liu, Shuxun; Cao, Xuetao

    2005-01-01

    Heat stress can alert innate immunity by inducing stress proteins such as heat-shock proteins (HSPs). However, it remains unclear whether heat stress affects the activation of antigen-presenting cell (APC) in response to pathogen-associated molecule patterns (PAMPs) by directly regulating pathogen recognition receptors (PRRs). As an important kind of PRRs, Toll-like receptors (TLRs) play critical roles in the activation of immune system. In this study, we demonstrated that heat shock up-regulated the expression of HSP70 as well as TLR2 and TLR4 in monocytes. The induction of TLRs was prior to that of HSP70, which suggesting the up-regulation of TLR2 and TLR4 might be independent of the induction of HSP70. Heat shock activated p38 kinase, extracellular signal-related kinase (ERK) and nuclear factor-kappa B (NF-κB) signal pathways in monocytes. Pretreatment with specific inhibitor of p38 kinase, but not those of ERK and NF-κB, inhibited heat shock-induced up-regulation of TLR2 and TLR4. This indicates that p38 pathway takes part in heat shock-induced up-regulation of TLR2 and TLR4. Heat shock also increased lipoteichoic acid- or lipopolysaccharide-induced interleukin-6 production by monocytes. These results suggest that the p38 kinase-mediated up-regulation of TLR2 and TLR4 might be involved in the enhanced response to PAMP in human monocytes induced by heat shock. PMID:15804289

  15. Nicotine enhances invasion and metastasis of human colorectal cancer cells through the nicotinic acetylcholine receptor downstream p38 MAPK signaling pathway.

    PubMed

    Xiang, Tao; Fei, Rushan; Wang, Zhe; Shen, Zhonglei; Qian, Jing; Chen, Wenbin

    2016-01-01

    Nicotine as a cigarette component is an established risk factor for colorectal cancer tumorigenesis. The downstream signaling pathways of nicotinic acetylcholine receptors (nAchRs) are believed to be responsible for the cellular effects. In the present study, we evaluated the effects and novel mechanisms for nicotine on the capacity for colorectal cancer cell invasion and metastasis. LOVO and SW620 colorectal cancer cells were stimulated with nicotine in vitro. A Transwell chamber model was applied to detect the capacity for tumor cell invasion. Assays for gelatin zymography and western blotting were applied to detect the activity and expression of metastasis-related matrix metalloproteinases (MMPs), respectively. Signal transduction was assessed by immunoblotting for the phosphorylation of relevant signal molecules and the application of pharmaceutical inhibitors. We showed that nicotine increased LOVO and SW620 colorectal cancer cell invasion along with enhanced activity and expression of MMP-1, -2 and -9. Nicotine increased phosphorylation of p38, ERK, Akt and PI3K p85 but had no effect on phosphorylation of JNK, or NF-κB. Of the pharmaceutical inhibitors of U0126 (ERK1/2 inhibitor), LY294002 (Akt activation inhibitor), SB239063 (p38 MAPK activation inhibitor) and hexamethonium (Hex) (nAchRs inhibitor), the cellular and molecular effects were reduced by the applications of SB239063 and Hex. We concluded that nicotine stimulates the invasion and metastasis of colon cancer cells in vitro via activation of the nAchRs and the p38 MAPK downstream signaling pathway. Therefore, p38 MAPK may have potential as a therapeutic target for smoking-related human colorectal cancer metastasis. PMID:26530054

  16. Panobinostat synergizes with zoledronic acid in prostate cancer and multiple myeloma models by increasing ROS and modulating mevalonate and p38-MAPK pathways

    PubMed Central

    Bruzzese, F; Pucci, B; Milone, M R; Ciardiello, C; Franco, R; Chianese, M I; Rocco, M; Di Gennaro, E; Leone, A; Luciano, A; Arra, C; Santini, D; Caraglia, M; Budillon, A

    2013-01-01

    Patients with advanced prostate cancer (PCa) and multiple myeloma (MM) have limited long-term responses to available therapies. The histone deacetylase inhibitor panobinostat has shown significant preclinical and clinical anticancer activity in both hematological and solid malignancies and is currently in phase III trials for relapsed MM. Bisphosphonates (BPs), such as zoledronic acid (ZOL), inhibit osteoclast-mediated bone resorption and are indicated for the treatment of bone metastasis. BPs, including ZOL, have also shown anticancer activity in several preclinical and clinical studies. In the present report, we found a potent synergistic antiproliferative effect of panobinostat/ZOL treatment in three PCa and three MM cell lines as well as in a PCa ZOL-resistant subline, independently of p53/KRAS status, androgen dependency, or the schedule of administration. The synergistic effect was also observed in an anchorage-independent agar assay in both ZOL-sensitive and ZOL-resistant cells and was confirmed in vivo in a PCa xenograft model. The co-administration of the antioxidant N-acetyl-L-cysteine blocked the increased reactive oxygen species generation and apoptosis observed in the combination setting compared with control or single-agent treatments, suggesting that oxidative injury plays a functional role in the synergism. Proapoptotic synergy was also partially antagonized by the addition of geranyl-geraniol, which bypasses the inhibition of farnesylpyrophosphate synthase by ZOL in the mevalonate pathway, supporting the involvement of this pathway in the synergy. Finally, at the molecular level, the inhibition of basal and ZOL-induced activation of p38-MAPK by panobinostat in sensitive and ZOL-resistant cells and in tumor xenografts could explain, at least in part, the observed synergism. PMID:24157872

  17. Panobinostat synergizes with zoledronic acid in prostate cancer and multiple myeloma models by increasing ROS and modulating mevalonate and p38-MAPK pathways.

    PubMed

    Bruzzese, F; Pucci, B; Milone, M R; Ciardiello, C; Franco, R; Chianese, M I; Rocco, M; Di Gennaro, E; Leone, A; Luciano, A; Arra, C; Santini, D; Caraglia, M; Budillon, A

    2013-01-01

    Patients with advanced prostate cancer (PCa) and multiple myeloma (MM) have limited long-term responses to available therapies. The histone deacetylase inhibitor panobinostat has shown significant preclinical and clinical anticancer activity in both hematological and solid malignancies and is currently in phase III trials for relapsed MM. Bisphosphonates (BPs), such as zoledronic acid (ZOL), inhibit osteoclast-mediated bone resorption and are indicated for the treatment of bone metastasis. BPs, including ZOL, have also shown anticancer activity in several preclinical and clinical studies. In the present report, we found a potent synergistic antiproliferative effect of panobinostat/ZOL treatment in three PCa and three MM cell lines as well as in a PCa ZOL-resistant subline, independently of p53/KRAS status, androgen dependency, or the schedule of administration. The synergistic effect was also observed in an anchorage-independent agar assay in both ZOL-sensitive and ZOL-resistant cells and was confirmed in vivo in a PCa xenograft model. The co-administration of the antioxidant N-acetyl-L-cysteine blocked the increased reactive oxygen species generation and apoptosis observed in the combination setting compared with control or single-agent treatments, suggesting that oxidative injury plays a functional role in the synergism. Proapoptotic synergy was also partially antagonized by the addition of geranyl-geraniol, which bypasses the inhibition of farnesylpyrophosphate synthase by ZOL in the mevalonate pathway, supporting the involvement of this pathway in the synergy. Finally, at the molecular level, the inhibition of basal and ZOL-induced activation of p38-MAPK by panobinostat in sensitive and ZOL-resistant cells and in tumor xenografts could explain, at least in part, the observed synergism. PMID:24157872

  18. N-Formyl peptides drive mitochondrial damage associated molecular pattern induced neutrophil activation through ERK1/2 and P38 MAP kinase signalling pathways.

    PubMed

    Hazeldine, Jon; Hampson, Peter; Opoku, Francis Adusei; Foster, Mark; Lord, Janet M

    2015-01-01

    that MAPK activation is required for mtDAMP-induced neutrophil activation and function. Our findings demonstrate that signalling through FPR-1 and activation of p38 and ERK1/2 MAPKs are key events in mtDAMP-induced neutrophil activation. Gaining an understanding of the signalling pathways involved in mtDAMP-induced neutrophil activation may assist in the development of future therapeutic strategies aimed at targeting the SIRS response to improve the outcome of the hospitalised trauma patient. Reducing the severity of the inflammatory response may realise substantial benefits for the severely injured trauma patient. PMID:25817163

  19. Probiotic-derived polyphosphate enhances the epithelial barrier function and maintains intestinal homeostasis through integrin-p38 MAPK pathway.

    PubMed

    Segawa, Shuichi; Fujiya, Mikihiro; Konishi, Hiroaki; Ueno, Nobuhiro; Kobayashi, Naoyuki; Shigyo, Tatsuro; Kohgo, Yutaka

    2011-01-01

    Probiotics exhibit beneficial effects on human health, particularly in the maintenance of intestinal homeostasis in a complex manner notwithstanding the diversity of an intestinal flora between individuals. Thus, it is highly probable that some common molecules secreted by probiotic and/or commensal bacteria contribute to the maintenance of intestinal homeostasis and protect the intestinal epithelium from injurious stimuli. To address this question, we aimed to isolate the cytoprotective compound from a lactobacillus strain, Lactobacillus brevis SBC8803 which possess the ability to induce cytoprotective heat shock proteins in mouse small intestine. L. brevis was incubated in MRS broth and the supernatant was passed through with a 0.2-µm filter. Caco2/bbe cells were treated with the culture supernatant, and HSP27 expression was evaluated by Western blotting. HSP27-inducible components were separated by ammonium sulfate precipitation, DEAE anion exchange chromatography, gel filtration, and HPLC. Finally, we identified that the HSP27-inducible fraction was polyphosphate (poly P), a simple repeated structure of phosphates, which is a common product of lactobacilli and other bacteria associated with intestinal microflora without any definitive physiological functions. Then, poly P was synthesized by poly P-synthesizing enzyme polyphosphate kinase. The synthesized poly P significantly induced HSP27 from Caco2/BBE cells. In addition, Poly P suppressed the oxidant-induced intestinal permeability in the mouse small intestine and pharmacological inhibitors of p38 MAPK and integrins counteract its protective effect. Daily intrarectal administration of poly P (10 µg) improved the inflammation grade and survival rate in 4% sodium dextran sulfate-administered mice. This study, for the first time, demonstrated that poly P is the molecule responsible for maintaining intestinal barrier actions which are mediated through the intestinal integrin β1-p38 MAPK. PMID:21858054

  20. p38- and MK2-dependent signalling promotes stress-induced centriolar satellite remodelling via 14-3-3-dependent sequestration of CEP131/AZI1

    PubMed Central

    Tollenaere, Maxim A. X.; Villumsen, Bine H.; Blasius, Melanie; Nielsen, Julie C.; Wagner, Sebastian A.; Bartek, Jiri; Beli, Petra; Mailand, Niels; Bekker-Jensen, Simon

    2015-01-01

    Centriolar satellites (CS) are small granular structures that cluster in the vicinity of centrosomes. CS are highly susceptible to stress stimuli, triggering abrupt displacement of key CS factors. Here we discover a linear p38-MK2-14-3-3 signalling pathway that specifically targets CEP131 to trigger CS remodelling after cell stress. We identify CEP131 as a substrate of the p38 effector kinase MK2 and pinpoint S47 and S78 as critical MK2 phosphorylation sites in CEP131. Ultraviolet-induced phosphorylation of these residues generates direct binding sites for 14-3-3 proteins, which sequester CEP131 in the cytoplasm to block formation of new CS, thereby leading to rapid depletion of these structures. Mutating S47 and S78 in CEP131 is sufficient to abolish stress-induced CS reorganization, demonstrating that CEP131 is the key regulatory target of MK2 and 14-3-3 in these structures. Our findings reveal the molecular mechanism underlying dynamic CS remodelling to modulate centrosome functions on cell stress. PMID:26616734

  1. Lactobacillus acidophilus induces cytokine and chemokine production via NF-κB and p38 mitogen-activated protein kinase signaling pathways in intestinal epithelial cells.

    PubMed

    Jiang, Yujun; Lü, Xuena; Man, Chaoxin; Han, Linlin; Shan, Yi; Qu, Xingguang; Liu, Ying; Yang, Shiqin; Xue, Yuqing; Zhang, Yinghua

    2012-04-01

    Intestinal epithelial cells can respond to certain bacteria by producing an array of cytokines and chemokines which are associated with host immune responses. Lactobacillus acidophilus NCFM is a characterized probiotic, originally isolated from human feces. This study aimed to test the ability of L. acidophilus NCFM to stimulate cytokine and chemokine production in intestinal epithelial cells and to elucidate the mechanisms involved in their upregulation. In experiments using intestinal epithelial cell lines and mouse models, we observed that L. acidophilus NCFM could rapidly but transiently upregulate a number of effector genes encoding cytokines and chemokines such as interleukin 1α (IL-1α), IL-1β, CCL2, and CCL20 and that cytokines showed lower expression levels with L. acidophilus NCFM treatment than chemokines. Moreover, L. acidophilus NCFM could activate a pathogen-associated molecular pattern receptor, Toll-like receptor 2 (TLR2), in intestinal epithelial cell lines. The phosphorylation of NF-κB p65 and p38 mitogen-activated protein kinase (MAPK) in intestinal epithelial cell lines was also enhanced by L. acidophilus NCFM. Furthermore, inhibitors of NF-κB (pyrrolidine dithiocarbamate [PDTC]) and p38 MAPK (SB203580) significantly reduced cytokine and chemokine production in the intestinal epithelial cell lines stimulated by L. acidophilus NCFM, suggesting that both NF-κB and p38 MAPK signaling pathways were important for the production of cytokines and chemokines induced by L. acidophilus NCFM. PMID:22357649

  2. Potassium supplementation inhibits IL-17A production induced by salt loading in human T lymphocytes via p38/MAPK-SGK1 pathway.

    PubMed

    Wen, Wen; Wan, Zhaofei; Ren, Keyu; Zhou, Dong; Gao, Qiyue; Wu, Yan; Wang, Lijun; Yuan, Zuyi; Zhou, Juan

    2016-06-01

    High salt intake contributes to the development of autoimmune/inflammatory diseases, while potassium supplementation antagonizes the effects. Interleukin (IL)-17A are tightly related with autoimmune/inflammatory diseases. Thus, we explored the effects and underlying molecular mechanism of high salt and potassium supplementation on IL-17A production in T lymphocytes. Forty-nine healthy participants received a low-salt, high-salt, followed by a high-salt diet plus potassium supplement for 7 days, respectively. Human T lymphocyte Jurkat cells were treated with different concentrations of NaCl and KCl. In the participants, IL-17A levels in plasma and in peripheral blood mononuclear cells (PBMC) were significantly increased after a high-salt diet, which was dramatically reversed when potassium was supplemented. In Jurkat cells, the addition of 40 mM NaCl markedly enhanced IL-17A production and the expression of phosphorylated p38/mitogen-activated protein kinase (MAPK) and its downstream target, serum/glucocorticoid-regulated kinase (SGK)1, whereas combined treatment with additional 2 mM KCl significantly decreased them. Respective inhibition of p38/MAPK and SGK1 suppressed IL-17A expression induced by NaCl, and KCl inhibited IL-17A production induced by specific activator of p38/MAPK. We conclude potassium supplementation has a blocking effect on IL-17A production in T lymphocytes induced by salt loading. This protective effect is mediated through the direct suppression of p38/MAPK-SGK1 pathway. PMID:27020669

  3. PDGF-D/PDGFRβ promotes tongue squamous carcinoma cell (TSCC) progression via activating p38/AKT/ERK/EMT signal pathway.

    PubMed

    Zhang, Hong; Sun, Jia-Dong; Yan, Ling-Jian; Zhao, Xiao-Peng

    2016-09-16

    Platelet-derived growth factor D (PDGF-D) signaling plays significant roles during the development and progression of human malignancies via interacting with the receptor of PDGF-D (PDGFR). Meanwhile, the majority of human tumor metastasis is closely associated with epithelial-mesenchymal transition (EMT). However, the underlying mechanism between PDGF-D/PDGFR signaling and EMT which involved in tumor metastasis remain dismal. This study aimed to investigate the role of PDGF-D signaling during EMT process of tongue squamous cell carcinoma (TSCC). In our study, the expression of PDGF-D and PDGFR were examined in primary TSCC samples and the expression of PDGF-D was also determined in TSCC cell lines. In addition, the correlation between PDGF-D expression and TSCC aggressive histopathological features was analyzed. Our results implied that upregulation of PDGFRβ in UM1 cells induced with exogenous PDGF-D can remarkably promote tumor cells invasiveness; conversely, when using small interfering RNA (siRNA), the invasiveness can be severely prohibited. Furthermore, PDGF-D downstream signal molecules p38, AKT, ERK and EMT biomarkers (E-cadherin, N-cadherin, Vimentin and snail) were measured using Western blot. Our results showed that PDGF-D can induce p38, AKT and ERK phosphorylation; downregulate epithelial markers and upregulate mesenchymal markers. On the contrary, PDGFRβ siRNA significantly prohibited p38, AKT and ERK phosphorylation; inhibited EMT process. Function analysis revealed that PDGFRβ siRNA obviously interfered with UM1 cell migration and invasion, according to transwell and wound healing assay. In conclusion, this study suggested that EMT process can be triggered by the PDGF-D/PDGFRβ axis in TSCC, and then involved in the tumor cell invasion via activation of p38/AKT/ERK/EMT pathway. PMID:27507215

  4. Platelet adhesion enhances the glycoprotein VI-dependent procoagulant response: Involvement of p38 MAP kinase and calpain.

    PubMed

    Siljander, P; Farndale, R W; Feijge, M A; Comfurius, P; Kos, S; Bevers, E M; Heemskerk, J W

    2001-04-01

    In the final stages of activation, platelets express coagulation-promoting activity by 2 simultaneous processes: exposure of aminophospholipids, eg, phosphatidylserine (PS), at the platelet surface, and formation of membrane blebs, which may be shed as microvesicles. Contact with collagen triggers both processes via platelet glycoprotein VI (GPVI). Here, we studied the capacity of 2 GPVI ligands, collagen-related peptide (CRP) and the snake venom protein convulxin (CVX), to elicit the procoagulant platelet response. In platelets in suspension, either ligand induced full aggregation and high Ca(2+) signals but little microvesiculation or PS exposure. However, most of the platelets adhering to immobilized CRP or CVX had exposed PS and formed membrane blebs after a prolonged increase in cytosolic [Ca(2+)](i). Platelets adhering to fibrinogen responded similarly but only when exposed to soluble CRP or CVX. By scanning electron microscopic analysis, the bleb-forming platelets were detected as either round, spongelike structures with associated microparticles or as arrays of vesicular cell fragments. The phosphorylation of p38 mitogen-activated protein kinase (MAPK) elicited by CRP and CVX was enhanced in fibrinogen-adherent platelets compared with that in platelets in suspension. The p38 inhibitor SB203580 and the calpain protease inhibitor calpeptin reduced only the procoagulant bleb formation, having no effect on PS exposure. Inhibition of p38 also downregulated calpain activity. We conclude that the procoagulant response evoked by GPVI stimulation is potentiated by platelet adhesion. The sequential activation of p38 MAPK and calpain appears to regulate procoagulant membrane blebbing but not PS exposure. PMID:11304481

  5. 8β-hydroxy-3-oxopimar-15-ene exerts anti-inflammatory effects by inhibiting ROS-mediated activation of the TRAF6-ASK1-p38 signaling pathway.

    PubMed

    Cho, Jae-Heung; Lee, Jong Hyun; Lee, Eun-Jung; Nam, Dongwoo; Shim, Bum Sang; Song, Mi-Yeon; Kim, Sung-Soo; Kim, Sung-Hoon; Jung, Sang Hoon; Chung, Won-Seok; Ahn, Kwang Seok

    2013-10-01

    The flying squirrel's droppings (Pteropus pselaphon) have been used for improving the blood circulation, arresting bleeding to treat hematological disorders, and reducing pain. Here, 8β-hydroxy-3-oxopimar-15-ene (OXO), one of main constituents of P. pselaphon, was examined for its anti-inflammatory activity in murine macrophages. We found that OXO significantly suppressed LPS-induced nitric oxide (NO) without exerting cytotoxic effects on RAW 264.7 cells. OXO inhibited the expression of LPS-induced iNOS and COX-2 protein and their mRNA in a dose-dependent manner. Also, TNF-α, IL-6, and PGE2 secretion was decreased by OXO in LPS-stimulated macrophages. These inflammatory biomarkers were attributed to the suppression of LPS-induced activation of p38 MAPK and subsequent activation of two components of AP-1 (c-Jun and c-Fos), but not of ERK, JNK, NF-κB. Moreover, OXO inhibited LPS-induced intracellular reactive oxygen species (ROS) production and co-incubation of OXO and hydrogen peroxide (H2O2) suppressed the phosphorylation of p38 in a concentration-dependent manner. In addition, OXO completely disrupted the formation of TRAF6-ASK complex in the cells. Therefore, we demonstrate here that OXO can potentially inhibit several biomarkers related to inflammation through inhibition of ROS-mediated activation of TRAF6-ASK1-p38 pathway. PMID:23914844

  6. Effect of silibinin and vitamin E on the ASK1-p38 MAPK pathway in D-galactosamine/lipopolysaccharide induced hepatotoxicity.

    PubMed

    Hashem, Reem M; Hassanin, Kamel Ma; Rashed, Laila A; Mahmoud, Mohamed O; Hassan, Mohamed G

    2016-06-01

    Apoptosis signal-regulating kinase 1 (ASK1), a redox-sensor mitogen-activated protein kinase kinase kinase (MAPKKK) that activates p38 MAPK pathways in oxidative stress-induced hepatotoxicity in D-galactosamine/lipopolysaccharide (D-GalN/LPS) model, is a key central pathway in which specific targeting of ASK1 deactivation is of a great therapeutic potential. We tested the effect of silibinin and vitamin E in curative and prophylactic manner of treatment on the negative modulators of ASK1, thioredoxin1 (Trx1), thioredoxin reductase1 (TrxR1), and the protein phosphatase (PP5), whereas they have previously proven to have hepatoprotective effect. Either curative or prophylactic silibinin and vitamin E groups significantly decreased ASK1 and p38 MAPK levels through increasing the gene expression of Trx1, TrxR1, and PP5 to reduce the oxidative stress as demonstrated by decreasing the levels of NADPH oxidase 4 (NOX4), TBARS and conjugated diene with a concomitant increase in the levels of GSH, CAT, and SOD. These results were confirmed by histopathology examination which illustrated progressive degenerative changes of hepatocytes such as hydropic degeneration, vacuolation, pyknosis, karyolysis, and loss of architecture of some cells in D-GalN/LPS treatment, and these features were alleviated with silibinin and vitamin E administration. In conclusion, silibinin and vitamin E decreased ASK1-p38 MAPK pathway through deactivating the upstream signalling ASK1 molecule via increasing the levels of Trx1 and TrxR1 as well as the PP5 to alleviate in D-GalN/LPS induced hepatotoxicity. PMID:26941058

  7. Netrin-1 induces the migration of Schwann cells via p38 MAPK and PI3K-Akt signaling pathway mediated by the UNC5B receptor

    SciTech Connect

    Lv, Jianwei; Sun, Xiaolei; Ma, Jianxiong; Ma, Xinlong; Zhang, Yang; Li, Fengbo; Li, Yanjun; Zhao, Zhihu

    2015-08-14

    Schwann cells (SCs) play an essentially supportive role in the regeneration of injured peripheral nerve system (PNS). As Netrin-1 is crucial for the normal development of nervous system (NS) and can direct the process of damaged PNS regeneration, our study was designed to determine the role of Netrin-1 in RSC96 Schwann cells (an immortalized rat Schwann cell line) proliferation and migration. Our studies demonstrated that Netrin-1 had no effect on RSC96 cells proliferation, while significantly promoted RSC96 cells migration. The Netrin-1-induced RSC96 cells migration was significantly attenuated by inhibition of p38 and PI3K through pretreatment with SB203580 and LY294002 respectively, but not inhibition of MEK1/2 and JNK by U0126-EtOH and SP600125 individually. Treatment with Netrin-1 enhanced the phosphorylation of p38 and Akt. QRT-PCR indicated that Netrin-1 and only its receptors Unc5a, Unc5b and Neogenin were expressed in RSC96 cells, among which Unc5b expressed the most. And UNC5B protein was significantly increased after stimulated by Netrin-1. In conclusion, we show here that Netrin-1-enhanced SCs migration is mediated by activating p38 MAPK and PI3K-Akt signal cascades via receptor UNC5B, which suggests that Netrin-1 could serve as a new therapeutic strategy and has potential application value for PNS regeneration. - Highlights: • Netrin-1 attracts RSC96 Schwann cells migration in a dose dependent manner. • Netrin-1 induced Schwann cells migration is p38 and PI3K-Akt signaling dependent. • UNC5B may be dominant receptor mediating Netrin-1′ effect on RSC96 cells motility. • Netrin-1 may promote peripheral nerve repair by enhancing Schwann cells motility.

  8. Plumbagin induces G2/M arrest, apoptosis, and autophagy via p38 MAPK- and PI3K/Akt/mTOR-mediated pathways in human tongue squamous cell carcinoma cells

    PubMed Central

    Pan, Shu-Ting; Qin, Yiru; Zhou, Zhi-Wei; He, Zhi-Xu; Zhang, Xueji; Yang, Tianxin; Yang, Yin-Xue; Wang, Dong; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone; PLB), a naturally occurring naphthoquinone isolated from the roots of Plumbaginaceae plants, has been reported to possess anticancer activities in both in vitro and in vivo studies, but the effect of PLB on tongue squamous cell carcinoma (TSCC) is not fully understood. This study aimed to investigate the effects of PLB on cell cycle distribution, apoptosis, and autophagy, and the underlying mechanisms in the human TSCC cell line SCC25. The results have revealed that PLB exerted potent inducing effects on cell cycle arrest, apoptosis, and autophagy in SCC25 cells. PLB arrested SCC25 cells at the G2/M phase in a concentration- and time-dependent manner with a decrease in the expression level of cell division cycle protein 2 homolog (Cdc2) and cyclin B1 and increase in the expression level of p21 Waf1/Cip1, p27 Kip1, and p53 in SCC25 cells. PLB markedly induced apoptosis and autophagy in SCC25 cells. PLB decreased the expression of the anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl) while increasing the expression level of the pro-apoptotic protein Bcl-2-associated X protein (Bax) in SCC25 cells. Furthermore, PLB inhibited phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), glycogen synthase kinase 3β (GSK3β), and p38 mitogen-activated protein kinase (p38 MAPK) pathways as indicated by the alteration in the ratio of phosphorylation level over total protein expression level, contributing to the autophagy inducing effect. In addition, we found that wortmannin (a PI3K inhibitor) and SB202190 (a selective inhibitor of p38 MAPK) strikingly enhanced PLB-induced autophagy in SCC25 cells, suggesting the involvement of PI3K- and p38 MAPK-mediated signaling pathways. Moreover, PLB induced intracellular reactive oxygen species (ROS) generation and this effect was attenuated by l-glutathione (GSH) and n-acetyl-l-cysteine (NAC). Taken

  9. Hyperbaric Oxygen Reduces Production of Reactive Oxygen Species in Neutrophils from Polytraumatized Patients Yielding in the Inhibition of p38 MAP Kinase and Downstream Pathways

    PubMed Central

    Windolf, Joachim; Wahlers, Thorsten

    2016-01-01

    Trauma represents the leading cause of death among young people in western countries. Among the beneficial role of neutrophils in host defence, excessive priming and activation of neutrophils after major trauma lead to an overwhelming inflammatory response and secondary host tissue injury due to the release of toxic metabolites and enzymes. Hyperbaric oxygen (HBO) therapy has been proposed to possess antiinflammatory effects and might represent an appropriate therapeutic option to lower inflammation in a broad range of patients. Here, we studied the effects of HBO on the activity of neutrophils isolated from severely injured patients (days 1–2 after trauma), in fact on the production of reactive oxygen species (ROS) and release of neutrophil extracellular traps (NETs). We found exposure to HBO therapy to significantly diminish phorbol-12-myristate-13-acetate (PMA)-induced ROS production in neutrophils isolated from patients and healthy volunteers. At the same time, marked decrease in NETs release was found in control cells and a less pronounced reduction in patient neutrophils. Impaired ability to produce ROS following exposure to HBO was demonstrated to be linked to a strong downregulation of the activity of p38 MAPK. Only slight suppression of ERK activity could be found. In addition, HBO did not influence neutrophil chemotaxis or apoptosis, respectively. Collectively, this study shows for the first time that HBO therapy suppresses ROS production in inflammatory human neutrophils, and thus might impair ROS-dependent pathways, e.g. kinases activation and NETs release. Thus, HBO might represent a feasible therapy for patients suffering from systemic inflammation, including those with multiple trauma. PMID:27529549

  10. Hyperbaric Oxygen Reduces Production of Reactive Oxygen Species in Neutrophils from Polytraumatized Patients Yielding in the Inhibition of p38 MAP Kinase and Downstream Pathways.

    PubMed

    Grimberg-Peters, Deborah; Büren, Carina; Windolf, Joachim; Wahlers, Thorsten; Paunel-Görgülü, Adnana

    2016-01-01

    Trauma represents the leading cause of death among young people in western countries. Among the beneficial role of neutrophils in host defence, excessive priming and activation of neutrophils after major trauma lead to an overwhelming inflammatory response and secondary host tissue injury due to the release of toxic metabolites and enzymes. Hyperbaric oxygen (HBO) therapy has been proposed to possess antiinflammatory effects and might represent an appropriate therapeutic option to lower inflammation in a broad range of patients. Here, we studied the effects of HBO on the activity of neutrophils isolated from severely injured patients (days 1-2 after trauma), in fact on the production of reactive oxygen species (ROS) and release of neutrophil extracellular traps (NETs). We found exposure to HBO therapy to significantly diminish phorbol-12-myristate-13-acetate (PMA)-induced ROS production in neutrophils isolated from patients and healthy volunteers. At the same time, marked decrease in NETs release was found in control cells and a less pronounced reduction in patient neutrophils. Impaired ability to produce ROS following exposure to HBO was demonstrated to be linked to a strong downregulation of the activity of p38 MAPK. Only slight suppression of ERK activity could be found. In addition, HBO did not influence neutrophil chemotaxis or apoptosis, respectively. Collectively, this study shows for the first time that HBO therapy suppresses ROS production in inflammatory human neutrophils, and thus might impair ROS-dependent pathways, e.g. kinases activation and NETs release. Thus, HBO might represent a feasible therapy for patients suffering from systemic inflammation, including those with multiple trauma. PMID:27529549

  11. Bone morphogenetic protein 2-induced human dental pulp cell differentiation involves p38 mitogen-activated protein kinase-activated canonical WNT pathway

    PubMed Central

    Yang, Jing; Ye, Ling; Hui, Tian-Qian; Yang, Dong-Mei; Huang, Ding-Ming; Zhou, Xue-Dong; Mao, Jeremy J; Wang, Cheng-Lin

    2015-01-01

    Both bone morphogenetic protein 2 (BMP2) and the wingless-type MMTV integration site (WNT)/β-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis. Cross-talk between BMP2 and WNT/β-catenin in osteoblast differentiation and bone formation has been identified. However, the roles and mechanisms of the canonical WNT pathway in the regulation of BMP2 in dental pulp injury and repair remain largely unknown. Here, we demonstrate that BMP2 promotes the differentiation of human dental pulp cells (HDPCs) by activating WNT/β-catenin signalling, which is further mediated by p38 mitogen-activated protein kinase (MAPK) in vitro. BMP2 stimulation upregulated the expression of β-catenin in HDPCs, which was abolished by SB203580 but not by Noggin or LDN193189. Furthermore, BMP2 enhanced cell differentiation, which was not fully inhibited by Noggin or LDN193189. Instead, SB203580 partially blocked BMP2-induced β-catenin expression and cell differentiation. Taken together, these data suggest a possible mechanism by which the elevation of β-catenin resulting from BMP2 stimulation is mediated by the p38 MAPK pathway, which sheds light on the molecular mechanisms of BMP2-mediated pulp reparative dentin formation. PMID:26047580

  12. Mechanical Strain Promotes Osteogenesis of BMSCs from Ovariectomized Rats via the ERK1/2 but not p38 or JNK-MAPK Signaling Pathways.

    PubMed

    Zhang, P; Dai, Q; Ouyang, N; Yang, X; Wang, J; Zhou, S; He, N; Fang, B; Jiang, L

    2015-01-01

    Osteoporosis has become a world-wide health problem. As a promising intervention, mechanical strain is considered to be an important factor in bone remodeling. However, the underlying mechanisms are still not clarified clearly. In the present study, we aim to investigate the possible mechanism by which mechanical stimulation induces osteogenic differentiation of bone mesenchymal stem cells (BMSCs) from ovariectomized rats (OVX BMSCs). The results demonstrated that intermittent mechanical strain (IMS) promoted osteogenic differentiation of OVX BMSCs by activating Runt-related transcription factor 2 (Runx2). When the extracellular regulated kinase1/2-mitogen activated protein kinases (ERK1/2-MAPK) signaling pathway was blocked, the osteogenenic effects of IMS were diminished; while blocking of the p38-MAPK signaling pathway had little effect on subsequent osteogenic events. In addition, the phosphorylation level of JNK was not affected by IMS. Our results indicated that strain-induced osteogenic differentiation of OVX BMSCs may take effect via ERK1/2-MAPK not p38 or c-Jun N-terminal (JNK)-MAPK signaling pathway. These findings may have implications for physical treatment of osteoporosis in vitro. PMID:26299771

  13. Madecassoside suppresses migration of fibroblasts from keloids: involvement of p38 kinase and PI3K signaling pathways.

    PubMed

    Song, Jie; Xu, Huan; Lu, Qian; Xu, Zhao; Bian, Difei; Xia, Yufeng; Wei, Zhifeng; Gong, Zhunan; Dai, Yue

    2012-08-01

    Keloid is a specific skin scar that expands beyond the boundaries of the original injury as it heals. The invasive nature of keloid and notable migratory activity of fibroblasts are a hallmark, which distinguishes keloids from other common scars. Madecassoside, a triterpenoid saponin occurring in Centella asiatica herbs, possesses unique pharmacological properties to enhance wound-healing and diminish keloid formation. However, the effects of madecassoside on the formation of keloid scars have been poorly understood. Here, we focused on the potential of madecassoside on the migration of keloid-derived fibroblasts (KFs) and its mechanism. Primary KF, originating from human earlobe keloids, were purified and cultured, and then treated with madecassoside (10, 30, and 100μM). In both transwell migration assays and scratch-wound-closure assays, KF migration was considerably suppressed by madecassoside pretreatment. Furthermore, KFs treated with madecassoside showed decreased F-actin filaments, as revealed by fluorescein isothiocyanate (FITC)-phalloidin staining and confocal microscopy. By Western blot analysis, madecassoside was shown to remarkably attenuate the phosphorylation of cofilin, p38 MAPK and phosphatidylinositol-3-kinase (PI3K)/AKT signaling, but only exhibited a minor effect on MMP-13 and little effect on ERK1/2 phosphorylation. It was concluded that madecassoside could be of great use in the treatment and/or prevention of hypertrophic scars and keloids. PMID:22360962

  14. Sesamol decreases melanin biosynthesis in melanocyte cells and zebrafish: Possible involvement of MITF via the intracellular cAMP and p38/JNK signalling pathways.

    PubMed

    Baek, Seung-hwa; Lee, Sang-Han

    2015-10-01

    The development of antimelanogenic agents is important for the prevention of serious aesthetic problems such as melasma, freckles, age spots and chloasma. The aim of this study was to investigate the antimelanogenic effect of sesamol, an active lignan isolated from Sesamum indicum, in melan-a cells. Sesamol strongly inhibited melanin biosynthesis and the activity of intracellular tyrosinase by decreasing cyclic adenosine monophosphate (cAMP) accumulation. Sesamol significantly decreased the expression of melanogenesis-related genes, such as tyrosinase, tyrosinase-related protein-1,2 (TRP-1,2), microphthalmia-associated transcription factor (MITF) and melanocortin 1 receptor (MC1R). In addition, sesamol also induces phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK). Moreover, sesamol dose-dependently decreased zebrafish pigment formation, tyrosinase activity and expression of melanogenesis-related genes. These findings indicate that sesamol inhibited melanin biosynthesis by down-regulating tyrosinase activity and melanin production via regulation of gene expression of melanogenesis-related proteins through modulation of MITF activity, which promoted phosphorylation of p38 and JNK in melan-a cells. Together, these results suggest that sesamol strongly inhibits melanin biosynthesis, and therefore, sesamol represents a new skin-whitening agent for use in cosmetics. PMID:26010596

  15. Aspergillus fumigatus-induced Interleukin-8 Synthesis by Respiratory Epithelial Cells Is Controlled by the Phosphatidylinositol 3-Kinase, p38 MAPK, and ERK1/2 Pathways and Not by the Toll-like Receptor-MyD88 Pathway*

    PubMed Central

    Balloy, Viviane; Sallenave, Jean-Michel; Wu, Yongzheng; Touqui, Lhousseine; Latgé, Jean-Paul; Si-Tahar, Mustapha; Chignard, Michel

    2008-01-01

    Previous studies have established that phagocytes are key cells of the pulmonary innate immune defense against A. fumigatus, an opportunistic fungus responsible of invasive pulmonary aspergillosis. Macrophages detect A. fumigatus via Toll-like receptors 2 and 4 (TLR2 and -4) and respond by the MyD88-NF-κB-dependent synthesis of inflammatory mediators. In the present study, we demonstrate that respiratory epithelial cells also sense A. fumigatus and participate in the host defense. Thus, the interaction of respiratory epithelial cells with germinating but not resting conidia of A. fumigatus results in interleukin (IL)-8 synthesis that is controlled by phosphatidylinositol 3-kinase, p38 MAPK, and ERK1/2. Using MyD88-dominant negative transfected cells, we also show that IL-8 production is not dependent on the TLR-MyD88 pathway, although the MyD88 pathway is activated by A. fumigatus and leads to NF-κB activation. Thus, our results provide evidence for the existence of two independent signaling pathways activated in respiratory epithelial cells by A. fumigatus, one that is MyD88-dependent and another that is My88-independent and involved in IL-8 synthesis. PMID:18703508

  16. Aspergillus fumigatus-induced interleukin-8 synthesis by respiratory epithelial cells is controlled by the phosphatidylinositol 3-kinase, p38 MAPK, and ERK1/2 pathways and not by the toll-like receptor-MyD88 pathway.

    PubMed

    Balloy, Viviane; Sallenave, Jean-Michel; Wu, Yongzheng; Touqui, Lhousseine; Latgé, Jean-Paul; Si-Tahar, Mustapha; Chignard, Michel

    2008-11-01

    Previous studies have established that phagocytes are key cells of the pulmonary innate immune defense against A. fumigatus, an opportunistic fungus responsible of invasive pulmonary aspergillosis. Macrophages detect A. fumigatus via Toll-like receptors 2 and 4 (TLR2 and -4) and respond by the MyD88-NF-kappaB-dependent synthesis of inflammatory mediators. In the present study, we demonstrate that respiratory epithelial cells also sense A. fumigatus and participate in the host defense. Thus, the interaction of respiratory epithelial cells with germinating but not resting conidia of A. fumigatus results in interleukin (IL)-8 synthesis that is controlled by phosphatidylinositol 3-kinase, p38 MAPK, and ERK1/2. Using MyD88-dominant negative transfected cells, we also show that IL-8 production is not dependent on the TLR-MyD88 pathway, although the MyD88 pathway is activated by A. fumigatus and leads to NF-kappaB activation. Thus, our results provide evidence for the existence of two independent signaling pathways activated in respiratory epithelial cells by A. fumigatus, one that is MyD88-dependent and another that is My88-independent and involved in IL-8 synthesis. PMID:18703508

  17. Extracellular Release of Annexin A2 is Enhanced upon Oxidative Stress Response via the p38 MAPK Pathway after Low-Dose X-Ray Irradiation.

    PubMed

    Kita, Kazuko; Sugita, Katsuo; Sato, Chihomi; Sugaya, Shigeru; Sato, Tetsuo; Kaneda, Atsushi

    2016-07-01

    The extracellular microenvironment affects cellular responses to various stressors including radiation. Annexin A2, which was initially identified as an intracellular molecule, is also released into the extracellular environment and is known to regulate diverse cell surface events, however, the molecular mechanisms underlying its release are not well known. In this study, we found that in cultured human cancer and non-cancerous cells an extracellular release of annexin A2 was greatly enhanced 1-4 h after a single 20 cGy X-ray dose, but not after exposure to ultraviolet C (UVC) radiation. Extracellular release of annexin A2 was also enhanced after H2O2 and nicotine treatments, which was suppressed by pretreatment with the antioxidant, N-acetyl cysteine. Among the oxidative stress pathway molecules examined in HeLa cells, AMP-activated protein kinase α (AMPKα) and p38 mitogen-activated protein kinase (MAPK) were mostly activated by low-dose X-ray radiation, and the p38 MAPK inhibitor, SB203580, but not compound C (an AMPKα inhibitor), suppressed the enhancement of the annexin A2 extracellular release after low-dose X irradiation. In addition, the enhancement was suppressed in the cells in which p38α MAPK was downregulated by siRNA. HeLa cells and human cultured cells preirradiated with 20 cGy or precultured in media from low-dose X-irradiated cells showed an increase in resistance to radiation-induced cell death, and the increase was suppressed by treatment of the irradiated cell-derived media with anti-annexin A2 antibodies. In addition, extracellularly added recombinant annexin A2 conferred cellular radiation resistance. These results indicate that an oxidative stress-activated pathway via p38 MAPK was involved in the extracellular release of annexin A2, and this pathway was stimulated by low-dose X-ray irradiation. Furthermore, released annexin A2 may function in low-dose ionizing radiation-induced responses, such as radioresistance. PMID:27356027

  18. MiR-125b acts as an oncogene in glioblastoma cells and inhibits cell apoptosis through p53 and p38MAPK-independent pathways

    PubMed Central

    Wu, N; Lin, X; Zhao, X; Zheng, L; Xiao, L; Liu, J; Ge, L; Cao, S

    2013-01-01

    Background: We have recently identified miR-125b upregulation in glioblastoma (GMB). The aim of this study is to determine the correlation between miR-125b expression and malignant grades of glioma and the genes targeted by miR-125b. Methods: Real-time PCR was employed to measure the expression level of miR-125b. Cell viability was evaluated by cell growth and colony formation in soft-agar assays. Cell apoptosis was determined by Hoechst 33342 staining and AnnexinV-FITC assay. The Luciferase assay was used to confirm the actual binding sites of p38MAPK mRNA. Western blot was used to detect the gene expression level. Results: The expression level of miR-125b is positively correlated with the malignant grade of glioma. Ectopic expression of miR-125b promotes the proliferation of GMB cells. Knockdown of endogenous miR-125b inhibits cell proliferation and promotes cell apoptosis. Further studies reveal that p53 is regulated by miR-125b. However, downregulation of the endogenous miR-125b also results in p53-independent apoptotic pathway leading to apoptosis in p53 mutated U251 cells and p53 knockdown U87 cells. Moreover, p38MAPK is also regulated by miR-125b and downregulation of miR-125b activates the p38MAPK-induced mitochondria apoptotic pathway. Conclusion: High-level expression of miR-125b is associated with poor outcomes of GMB. MiR-125b may have an oncogenic role in GMB cells by promoting cell proliferation and inhibiting apoptosis. PMID:24169356

  19. 1,25(OH)2D3 inhibits high glucose-induced apoptosis and ROS production in human peritoneal mesothelial cells via the MAPK/P38 pathway.

    PubMed

    Yang, Lina; Wu, Lan; Du, Shuyan; Hu, Ye; Fan, Yi; Ma, Jianfei

    2016-07-01

    The regulation of cell proliferation, differentiation and immunomodulation are affected by 1,25(OH)2D3. However, its function during apoptosis and oxidative stress in human peritoneal mesothelial cells (HPMCs) remains unknown. The aim of the present study was to investigate whether the regulation of apoptosis and oxidative stress have therapeutic relevance in peritoneal dialysis (PD) therapy. The present study investigated the effects of 1,25(OH)2D3 on high glucose (HG)-induced apoptosis and reactive oxygen species (ROS) production in HPMCs, and examined the underlying molecular mechanisms. Flow cytometry and western blotting were performed to detect cell apoptosis, 2,7-dichlorofluorescein diacetate was used to measure reactive oxygen species production and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to measure cell viability. The results of the present study demonstrated that exposure to HG increased apoptosis and ROS production in HPMCs, whereas pretreatment with 1,25(OH)2D3 significantly inhibited HG‑induced apoptosis and ROS production. Further analysis revealed that 1,25(OH)2D3 facilitated cell survival via the MAPK/P38 pathway. The results of the present study indicate that 1,25(OH)2D3 inhibits apoptosis and ROS production in HG‑induced HPMCs via inhibition of the MAPK/P38 pathway. PMID:27220355

  20. Pristane primed rat T cells enhance TLR3 expression of fibroblast-like synoviocytes via TNF-α initiated p38 MAPK and NF-κB pathways.

    PubMed

    Zhu, Wenhua; Jiang, Congshan; Xu, Jing; Geng, Manman; Wu, Xiaoying; Sun, Jian; Ma, Jie; Holmdahl, Rikard; Meng, Liesu; Lu, Shemin

    2015-02-01

    Based on pristane-induced arthritis (PIA), we found that T cells mediate TLR3 overexpression in fibroblast-like synoviocytes (FLS). The aim of this study is to determine key factors by which T cells induce TLR3 expression. Rat FLS were co-cultured with pristane primed T cell conditioned medium (PPT medium), and TLR3 expression of FLS was significantly induced. TNF-α, IFN-γ and IL-17 were dominantly expressed in PIA T cells. The overexpression of TLR3 and its related genes in FLS co-cultured with PPT medium could be reduced through blocking TNF-α pathway. CD4(+) T cells from spleen of PIA rats showed increase of TNF-α secretion. P38 MAPK and NF-κB were activated in FLS by PPT medium, and their inhibitors decreased TLR3 upregulation significantly. Finally, TNF-α induced TLR3 expression was confirmed in human synovial cells. Summarily, TNF-α derived from pristane primed T cells induced TLR3 expression of FLS through activating p38 MAPK and NF-κB pathways. PMID:25533241

  1. Improvement of Radiotherapy-Induced Lacrimal Gland Injury by Induced Pluripotent Stem Cell-Derived Conditioned Medium via MDK and Inhibition of the p38/JNK Pathway

    PubMed Central

    Zhang, Yanqing; Deng, Chenliang; Qian, Jiang; Zhang, Mingui; Li, Xiaofeng

    2014-01-01

    Radiation therapy is the most widely used and effective treatment for orbital tumors, but it causes dry eye due to lacrimal gland damage. Induced pluripotent stem cell-derived conditioned medium (iPSC-CM) has been shown to rescue different types of tissue damage. The present study investigated the mechanism of the potential radioprotective effect of IPS cell-derived conditioned medium (iPSC-CM) on gamma-irradiation-induced lacrimal gland injury (RILI) in experimental mice. In this study, we found that iPSC-CM ameliorated RILI. iPSC-CM markedly decreased radiotherapy induced inflammatory processes, predominantly through suppressing p38/JNK signaling. Further signaling pathway analyses indicated that iPSC-CM could suppress Akt (Protein Kinase B, PKB) phosphorylation. High levels of midkine (MDK) were also found in iPSC-CM and could be involved in lacrimal gland regeneration by promoting cell migration and proliferation. Thus, our study indicates that inhibiting the p38/JNK pathway or increasing the MDK level might be a therapeutic target for radiation-induced lacrimal gland injury. PMID:25314301

  2. Spinal inhibition of p38 MAP kinase reduces inflammatory and neuropathic pain in male but not female mice: Sex-dependent microglial signaling in the spinal cord.

    PubMed

    Taves, Sarah; Berta, Temugin; Liu, Da-Lu; Gan, Sophie; Chen, Gang; Kim, Yong Ho; Van de Ven, Thomas; Laufer, Stefan; Ji, Ru-Rong

    2016-07-01

    Previous studies have shown that activation of p38 mitogen-activating kinase (MAPK) in spinal microglia participates in the generation of inflammatory and neuropathic pain in various rodent models. However, these studies focused on male mice to avoid confounding effects of the estrous cycle of females. Recent studies have shown that some spinal pro-inflammatory signaling such as Toll-like receptor 4-mediated signaling contributes to pain hypersensitivity only in male mice. In this study we investigated the distinct role of spinal p38 in inflammatory and neuropathic pain using a highly selective p38 inhibitor skepinone. Intrathecal injection of skepinone prevented formalin induced inflammatory pain in male but not female mice. Furthermore, intrathecal skepinone reduced chronic constriction injury (CCI) induced neuropathic pain (mechanical allodynia) in male mice on CCI-day 7 but not CCI-day 21. This male-dependent inhibition of neuropathic pain also occurred in rats following intrathecal skepinone. Nerve injury induced spinal p38 activation (phosphorylation) in CX3CR1-GFP(+) microglia on CCI-day 7, and this activation was more prominent in male mice. In contrast, CCI induced comparable microgliosis and expression of the microglial markers CX3CR1 and IBA-1 in both sexes. Notably, intraperitoneal or local perineural administration of skepinone inhibited CCI-induced mechanical allodynia in both sexes of mice. Finally, skepinone only reduced the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) in lamina IIo neurons of spinal cord slices of males 7days post CCI. Therefore, the sex-specific p38 activation and signaling is confined to the spinal cord in inflammatory and neuropathic pain conditions. PMID:26472019

  3. Anti-Proliferative Effect of Naringenin through p38-Dependent Downregulation of Cyclin D1 in Human Colorectal Cancer Cells

    PubMed Central

    Song, Hun Min; Park, Gwang Hun; Eo, Hyun Ji; Lee, Jin Wook; Kim, Mi Kyoung; Lee, Jeong Rak; Lee, Man Hyo; Koo, Jin Suk; Jeong, Jin Boo

    2015-01-01

    Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. However, more detailed mechanism by which NAR exerts anti-cancer properties still remains unanswered. Thus, in this study, we have shown that NAR down-regulates the level of cyclin D1 in human colorectal cancer cell lines, HCT116 and SW480. NAR inhibited the cell proliferation in HCT116 and SW480 cells and decreased the level of cyclin D1 protein. Inhibition of proteasomal degradation by MG132 blocked NAR-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with NAR. In addition, NAR increased the phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine blocked cyclin D1 downregulation by NAR. p38 inactivation attenuated cyclin D1 downregulation by NAR. From these results, we suggest that NAR-mediated cyclin D1 downregulation may result from proteasomal degradation through p38 activation. The current study provides new mechanistic link between NAR, cyclin D1 downregulation and cell growth in human colorectal cancer cells. PMID:26157550

  4. TRPM7 Activates m-Calpain by Stress-Dependent Stimulation of p38 MAPK and c-Jun N-Terminal Kinase

    PubMed Central

    Su, Li-Ting; Chen, Hsiang-Chin; González-Pagán, Omayra; Overton, Jeffrey D.; Xie, Jia; Yue, Lixia; Runnels, Loren W.

    2010-01-01

    Summary TRPM7 is a Ca2+ and Mg2+ permeant ion channel in possession of its own kinase domain. In a previous study we showed that overexpression of the channel-kinase in HEK-293 cells produced cell rounding and loss of adhesion which was dependent upon the Ca2+-dependent protease m-calpain. The TRPM7-elicited change in cell morphology was channel-dependent and occurred without any significant increase in cytosolic Ca2+. Here we demonstrate that overexpression of TRPM7 increased levels of cellular reactive oxygen species (ROS) and nitric oxide (NO), causing the activation of p38 MAP kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK). Application of inhibitors of p38 MAPK and JNK blocked TRPM7-induced cell rounding and activation of m-calpain, without affecting the phosphorylation state of the protease. Overexpression of TRPM7 increased intracellular Mg2+; however, when the concentrations of either external Ca2+ or Mg2+ was increased to favor permeation of one divalent cation over the other, a similar increase in cell rounding and calpain activity was detected, indicating that TRPM7-mediated activation of m-calpain is not dependent on the nature of the divalent conducted by the channel. Application of inhibitors of nitric oxide synthase and mitochondrial-derived ROS reduced TRPM7-induced increases in nitric oxide and ROS production, blocked the change in cell morphology, and reduced cellular calpain activity. Collectively, our data reveal that excessive TRPM7 channel activity causes oxidative and nitrosative stress, producing cell rounding mediated by p38 MAPK/JNK dependent activation of m-calpain. PMID:20070945

  5. Resveratrol inhibits hyperglycemia-driven ROS-induced invasion and migration of pancreatic cancer cells via suppression of the ERK and p38 MAPK signaling pathways.

    PubMed

    Cao, Lei; Chen, Xin; Xiao, Xue; Ma, Qingyong; Li, Wei

    2016-08-01

    Increasing evidence suggests that there is a strong relationship between diabetes mellitus (DM) and pancreatic cancer. Our previous study revealed that hyperglycemia could enhance the invasive and migratory activities of pancreatic cancer cells. Resveratrol, a natural polyphenolic phytoalexin, has many biological and pharmaceutical properties, including antioxidant and anti-tumorigenic capabilities. The aim of the present study was to evaluate whether resveratrol affects hyperglycemia-induced reactive oxygen species (ROS) production as well as the invasion and migration of pancreatic cancer and its underlying mechanisms. Human pancreatic cancer Panc-1 cells were exposed to high glucose condition with or without resveratrol, N-acetylcysteine (NAC, a scavenger of free radicals), PD 98059 (an ERK inhibitor) or SB 203580 (a p38 MAPK inhibitor). The intracellular ROS and hydrogen peroxide (H2O2) were determined using 2,7-dichlorodihydrofluorecein diacetate and H2O2 assay. MTT, wound healing assay and transwell matrigel invasion assay were used to detect the proliferation, migration and invasion potential of cancer cells. The expressions of uPA, E-cadherin and Glut-1 were examined using QT-PCR and western blot analysis at mRNA and protein levels. The activation of p-ERK, p-p38 and p-NF-κB were measured by western blot analysis. The results of the present study showed that resveratrol could significantly decrease high glucose-induced production of ROS and H2O2 in Panc-1 cells. Resveratrol was also able to inhibit high glucose-induced proliferation, migration and invasion of pancreatic cancer cells. High glucose-modulated expression of uPA, E-cadherin and Glut-1 were inhibited by resveratrol. In addition, high glucose-induced activation of ERK and p38 MAPK signaling pathways as well as the transcription factor NF-κB could also be suppressed by resveratrol. Furthermore, resveratrol was able to suppress H2O2-induced migration and invasion abilities of pancreatic cancer

  6. Ghrelin protects against depleted uranium-induced apoptosis of MC3T3-E1 cells through oxidative stress-mediated p38-mitogen-activated protein kinase pathway.

    PubMed

    Hao, Yuhui; Liu, Cong; Huang, Jiawei; Gu, Ying; Li, Hong; Yang, Zhangyou; Liu, Jing; Wang, Weidong; Li, Rong

    2016-01-01

    Depleted uranium (DU) mainly accumulates in the bone over the long term. Osteoblast cells are responsible for the formation of bone, and they are sensitive to DU damage. However, studies investigating methods of reducing DU damage in osteoblasts are rarely reported. Ghrelin is a stomach hormone that stimulates growth hormones released from the hypothalamic-pituitary axis, and it is believed to play an important physiological role in bone metabolism. This study evaluates the impact of ghrelin on DU-induced apoptosis of the osteoblast MC3T3-E1 and investigates its underlying mechanisms. The results show that ghrelin relieved the intracellular oxidative stress induced by DU, eliminated reactive oxygen species (ROS) and reduced lipid peroxidation by increasing intracellular GSH levels; in addition, ghrelin effectively suppressed apoptosis, enhanced mitochondrial membrane potential, and inhibited cytochrome c release and caspase-3 activation after DU exposure. Moreover, ghrelin significantly reduced the expression of DU-induced phosphorylated p38-mitogen-activated protein kinase (MAPK). A specific inhibitor (SB203580) or specific siRNA of p38-MAPK could significantly suppress DU-induced apoptosis and related signals, whereas ROS production was not affected. In addition, ghrelin receptor inhibition could reduce the anti-apoptosis effect of ghrelin on DU and reverse the effect of ghrelin on intracellular ROS and p38-MAPK after DU exposure. These results suggest that ghrelin can suppress DU-induced apoptosis of MC3T3-E1 cells, reduce DU-induced oxidative stress by interacting with its receptor, and inhibit downstream p38-MAPK activation, thereby suppressing the mitochondrial-dependent apoptosis pathway. PMID:26529667

  7. Activation of the p38 MAPK/Akt/ERK1/2 signal pathways is required for the protein stabilization of CDC6 and cyclin D1 in low-dose arsenite-induced cell proliferation.

    PubMed

    Liu, Youhong; Hock, Janet M; Sullivan, Con; Fang, Geying; Cox, Allison J; Davis, Kathleen T; Davis, Bruce H; Li, Xiong

    2010-12-15

    Arsenic trioxide (ATO) is a first-line anti-cancer agent for acute promyelocytic leukemia, and induces apoptosis in other solid cancer cell lines including breast cancer cells. However, as with arsenites found in drinking water and used as raw materials for wood preservatives, insecticides, and herbicides, low doses of ATO can induce carcinogenesis after long-term exposure. At 24 h after exposure, ATO (0.01-1 µM) significantly increased cell proliferation and promoted cell cycle progression from the G1 to S/G2 phases in the non-tumorigenic MCF10A breast epithelial cell line. The expression of 14 out of 96 cell-cycle-associated genes significantly increased, and seven of these genes including cell division cycle 6 (CDC6) and cyclin D1 (CCND1) were closely related to cell cycle progression from G1 to S phase. Low-dose ATO steadily increased gene transcript and protein levels of both CDC6 and cyclin D1 in a dose- and time-dependent manner. Low-dose ATO produced reactive oxygen species (ROS), and activated the p38 MAPK, Akt, and ERK1/2 pathways at different time points within 60 min. Small molecular inhibitors and siRNAs inhibiting the activation of p38 MAPK, Akt, and ERK1/2 decreased the ATO-increased expression of CDC6 protein. Inhibiting the activation of Akt and ERK1/2, but not p38 MAPK, decreased the ATO-induced expression of cyclin D1 protein. This study reports for the first time that p38 MAPK/Akt/ERK1/2 activation is required for the protein stabilization of CDC6 in addition to cyclin D1 in ATO-induced cell proliferation and cell cycle modulation from G1 to S phase. PMID:20862710

  8. Diosgenin induces hypoxia-inducible factor-1 activation and angiogenesis through estrogen receptor-related phosphatidylinositol 3-kinase/Akt and p38 mitogen-activated protein kinase pathways in osteoblasts.

    PubMed

    Yen, Men Luh; Su, Jen Liang; Chien, Chung Liang; Tseng, Kuang Wen; Yang, Ching Yao; Chen, Wei Fang; Chang, Chiao Chia; Kuo, Min Liang

    2005-10-01

    Diosgenin, extracted from the root of wild yam (Dioscorea villosa), has been reported to demonstrate an opportunity for medical application. Vascular endothelial growth factor-A (VEGF-A) plays an important role in bone-related angiogenesis, a critical process occurring during bone formation and fracture healing. In this study, we examine whether diosgenin is able to induce VEGF-A expression and to promote angiogenesis in osteoblasts. For murine MC3T3-E1 preosteoblast-like cells, VEGF-A mRNA and protein expression seemed to be significantly elevated in response to diosgenin in a concentration-dependent fashion. Conditioned media prepared from cells treated with diosgenin induced strong angiogenic activity in either in vitro or ex vivo angiogenesis assay. Furthermore, diosgenin treatment increased the stability and activity of HIF-1alpha protein. Inhibition of HIF-1alpha activity by transfection with DN-HIF-1alpha significantly diminished diosgenin-mediated VEGF-A up-regulation. The use of pharmacological inhibitors or genetic inhibition revealed that both the phosphatidylinositol 3-kinase (PI3K)/Akt and p38 signaling pathways were potentially required for diosgenin-induced HIF-1 activation and subsequent VEGF-A up-regulation. It is noteworthy that an estrogen receptor binding assay revealed that diosgenin has the strong ability to replace [(3)H]estradiol bound to estrogen receptor (IC(50), 10 nM). In addition, the specific estrogen receptor antagonists ICI 182,780 (faslodex) and tamoxifen were noted to be able to strongly inhibit diosgenin-induced, src kinase-dependent Akt and p38 MAPK activation. Taken together, such results provide evidence that diosgenin up-regulates VEGF-A and promotes angiogenesis in preosteoblast-like cells by a hypoxia-inducible factor-1alpha-dependent mechanism involving the activation of src kinase, p38 MAPK, and Akt signaling pathways via estrogen receptor. PMID:15998873

  9. Cyclin-Dependent Kinase Inhibitor P1446A Induces Apoptosis in a JNK/p38 MAPK-Dependent Manner in Chronic Lymphocytic Leukemia B-Cells

    PubMed Central

    Paiva, Cody; Godbersen, J. Claire; Soderquist, Ryan S.; Rowland, Taylor; Kilmarx, Sumner; Spurgeon, Stephen E.; Brown, Jennifer R.; Srinivasa, Sreesha P.; Danilov, Alexey V.

    2015-01-01

    CDK (cyclin-dependent kinase) inhibitors have shown remarkable activity in CLL, where its efficacy has been linked to inhibition of the transcriptional CDKs (7 and 9) and deregulation of RNA polymerase and short-lived pro-survival proteins such as MCL1. Furthermore, ER (endoplasmic reticulum) stress has been implicated in CDK inhibition in CLL. Here we conducted a pre-clinical study of a novel orally active kinase inhibitor P1446A in CLL B-cells. P1446A inhibited CDKs at nanomolar concentrations and induced rapid apoptosis of CLL cells in vitro, irrespective of chromosomal abnormalities or IGHV mutational status. Apoptosis preceded inactivation of RNA polymerase, and was accompanied by phosphorylation of stress kinases JNK (c-Jun N-terminal kinase) and p38 MAPK (mitogen-activated protein kinase). Pharmacologic inhibitors of JNK/p38 MAPK conferred protection from P1446A-mediated apoptosis. Treatment with P1446A led to a dramatic induction of NOXA in a JNK-dependent manner, and sensitized CLL cells to ABT-737, a BH3-mimetic. We observed concurrent activation of apoptosis stress-inducing kinase 1 (ASK1) and its interaction with inositol-requiring enzyme 1 (IRE1) and tumor necrosis factor receptor-associated factor 2 (TRAF2) in CLL cells treated with P1446A, providing insights into upstream regulation of JNK in this setting. Consistent with previous reports on limited functionality of ER stress mechanism in CLL cells, treatment with P1446A failed to induce an extensive unfolded protein response. This study provides rationale for additional investigations of P1446A in CLL. PMID:26606677

  10. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways.

    PubMed

    Yan, Tingting; Zhao, Yan; Zhang, Xia; Lin, Xiaotong

    2016-03-01

    Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. Acetaldehyde, the most toxic metabolite of ethanol, mediates the brain tissue damage and cognitive dysfunction induced by chronic excessive alcohol consumption. In this study, the effect of astaxanthin, a marine bioactive compound, on acetaldehyde-induced cytotoxicity was investigated in SH-SY5Y cells. It was found that astaxanthin protected cells from apoptosis by ameliorating the effect of acetaldehyde on the expression of Bcl-2 family proteins, preventing the reduction of anti-apoptotic protein Bcl-2 and the increase of pro-apoptotic protein Bak induced by acetaldehyde. Further analyses showed that astaxanthin treatment inhibited acetaldehyde-induced reduction of the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB). Astaxanthin treatment also prevented acetaldehyde-induced increase of the level of activated p38 mitogen-activated protein kinase (MAPK) and decrease of the level of activated extracellular signal-regulated kinases (ERKs). Activation of Akt/CREB pathway promotes cell survival and is involved in the upregulation of Bcl-2 gene. P38MAPK plays a critical role in apoptotic events while ERKs mediates the inhibition of apoptosis. Thus, astaxanthin may inhibit acetaldehyde-induced apoptosis through promoting the activation of Akt/CREB and ERKs and blocking the activation of p38MAPK. In addition, astaxanthin treatment suppressed the oxidative stress induced by acetaldehyde and restored the antioxidative capacity of SH-SY5Y cells. Therefore, astaxanthin may protect cells against acetaldehyde-induced cytotoxicity through maintaining redox balance and modulating apoptotic and survival signals. The results suggest that astaxanthin treatment may be beneficial for preventing neurotoxicity associated with acetaldehyde and excessive alcohol consumption. PMID:26978376