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Sample records for p38 dependent pathway

  1. Bupivacaine induces apoptosis via mitochondria and p38 MAPK dependent pathways.

    PubMed

    Lu, Jun; Xu, Shi Yuan; Zhang, Qing Guo; Xu, Rui; Lei, Hong Yi

    2011-04-25

    Mitochondria and the p38 mitogen-activated protein kinase (MAPK) pathways play important roles in apoptosis. Although the effect of bupivacaine on apoptosis is known, it remains unclear whether bupivacaine induces apoptosis via mitochondrial depolarization and the p38 MAPK activity. In this study, SH-SY5Y cells were pretreated respectively with 50μM 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), 10μM 4-(4-Fluorophenyl)-2-[4-(methylsulfinyl)phenyl]-5-(4-pyridyl)-1H-imidazole (SB203580), and 50μM DIDS plus 10μM SB203580 30min prior to the treatment with either 1mM bupivacaine or an equivalent amount of medium. The cell viability, mitochondrial membrane potential, phospho-p38 MAPK (p-p38 MAPK) and cell apoptosis were investigated with MTT assay, western blots, Hoechst 33258 staining and flow cytometry assay. In addition, the roles of chloridion (Cl(-)) channel and reactive oxygen species were studied to explore the molecular mechanism of bupivacaine-induced mitochondrial injury. Pretreatment with DIDS could attenuate reactive oxygen species production, the phosphorylation of p38MAPK, dissipation of mitochondrial membrane potential and apoptosis of SH-SY5Y cells induced by bupivacaine. Pretreatment with SB203580 could attenuate apoptosis, but could not attenuate reactive oxygen species production, or dissipation of mitochondrial membrane potential induced by bupivacaine. These findings indicate that the mitochondrial anion channel and p38 MAPK pathway are implicated in bupicavaine-induced apoptosis. Bupivacaine-induced reactive oxygen species production results in an alteration in the permeability of the mitochondrial membranes and Cl(-) influx into mitochondria, which seems to be responsible for mitochondrial depolarization and the p38 MAPK activation.

  2. Rit GTPase Regulates a p38 MAPK-Dependent Neuronal Survival Pathway

    PubMed Central

    Cai, Weikang; Rudolph, Jennifer L.; Sengoku, Tomoko; Andres, Douglas A.

    2012-01-01

    Rit, along with Rin and Drosophila Ric, comprises the Rit subfamily of Ras-related small GTPases. Although the cellular functions of many Ras family GTPases are well established, the physiological significance of Rit remains poorly understood. Loss of Rit sensitizes multiple mammalian cell lines and mouse embryonic fibroblasts (MEFs) derived from Rit−/− mice to oxidative stress-mediated apoptosis. However, whether Rit-mediated pro-survival signaling extends to other cell types, particularly neurons, is presently unknown. Here, to examine these issues we generated a transgenic mouse overexpressing constitutively active Rit (RitQ79L) exclusively in neurons, under control of the Synapsin I promoter. Active Rit-expressing hippocampal neurons display a dramatic increase in oxidative stress resistance. Moreover, pharmacological inhibitor studies demonstrate that p38 MAPK, rather than a MEK/ERK signaling cascade, is required for Rit-mediated protection. Together, the present studies identify a critical role for the Rit-p38 MAPK signaling cascade in promoting hippocampal neuron survival following oxidative stress. PMID:23123784

  3. p38 mitogen-activated protein kinase-dependent and -independent intracellular signal transduction pathways leading to apoptosis in human neutrophils.

    PubMed

    Frasch, S C; Nick, J A; Fadok, V A; Bratton, D L; Worthen, G S; Henson, P M

    1998-04-03

    Human neutrophils undergo apoptosis spontaneously when cultured in vitro; however, the signal transduction pathways involved remain largely unknown. In some cell types, c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase (MAPK) have been implicated in the pathways leading to stress-induced apoptosis. In this study, we begin to define two pathways leading to apoptosis in the neutrophil induced either by stress stimuli (UV, hyperosmolarity, sphingosine) or by anti-Fas antibody or overnight culture in vitro (spontaneous apoptosis). Apoptosis induced by stress stimuli activated p38 MAPK, and apoptosis was inhibited by the specific p38 MAPK inhibitor, 6-(4-Fluorophenyl)-2.3-dihydro-5-(4-puridinyl)imidazo(2, 1-beta)thiazole dihydrochloride. Furthermore, differentiation of HL-60 cells toward the neutrophil phenotype resulted in a loss in c-Jun NH2-terminal kinase activation with concomitant acquisition of formylmethionylleucylphenylalanine-stimulatable and stress-inducible p38 MAPK activity as well as apoptosis blockade by the p38 MAPK inhibitor. In contrast, anti-Fas-induced or spontaneous apoptosis occurred independent of p38 MAPK activation and was not blocked by the inhibitor. Both pathways appear to utilize member(s) of the caspase family, since pretreatment with either Val-Ala-Asp-fluoromethyl ketone or Asp-Glu-Val-Asp-fluoromethyl ketone inhibited apoptosis induced by each of the stimuli. We propose the presence of at least two pathways leading to apoptosis in human neutrophils, a stress-activated pathway that is dependent on p38 MAPK activation and an anti-FAS/spontaneous pathway that is p38 MAPK-independent.

  4. A Novel Chromone Derivative with Anti-Inflammatory Property via Inhibition of ROS-Dependent Activation of TRAF6-ASK1-p38 Pathway

    PubMed Central

    Liu, Hailiang; Xu, Rui; Feng, Lili; Guo, Wenjie; Cao, Ning; Qian, Cheng; Teng, Peng; Wang, Lu; Wu, Xuefeng; Sun, Yang; Li, Jianxin; Shen, Yan; Xu, Qiang

    2012-01-01

    The p38 MAPK signaling pathway plays a pivotal role in inflammation. Targeting p38 MAPK may be a potential strategy for the treatment of inflammatory diseases. In the present study, we show that a novel chromone derivative, DCO-6, significantly reduced lipopolysaccharide (LPS)-induced production of nitric oxide, IL-1β and IL-6, decreased the levels of iNOS, IL-1β and IL-6 mRNA expression in both RAW264.7 cells and mouse primary peritoneal macrophages, and inhibited LPS-induced activation of p38 MAPK but not of JNK, ERK. Moreover, DCO-6 specifically inhibited TLR4-dependent p38 activation without directly inhibiting its kinase activity. LPS-induced production of intracellular reactive oxygen species (ROS) was remarkably impaired by DCO-6, which disrupted the formation of the TRAF6-ASK1 complex. Administering DCO-6 significantly protected mice from LPS-induced septic shock in parallel with the inhibition of p38 activation and ROS production. Our results indicate that DCO-6 showed anti-inflammatory properties through inhibition of ROS-dependent activation of TRAF6-ASK1-p38 pathway. Blockade of the upstream events required for p38 MAPK action by DCO-6 may provide a new therapeutic option in the treatment of inflammatory diseases. PMID:22720096

  5. A novel cardioprotective p38-MAPK/mTOR pathway.

    PubMed

    Hernández, Gonzalo; Lal, Hind; Fidalgo, Miguel; Guerrero, Ana; Zalvide, Juan; Force, Thomas; Pombo, Celia M

    2011-12-10

    Despite intensive study, the mechanisms regulating activation of mTOR and the consequences of that activation in the ischemic heart remain unclear. This is particularly true for the setting of ischemia/reperfusion (I/R) injury. In a mouse model of I/R injury, we observed robust mTOR activation, and its inhibition by rapamycin increased injury. Consistent with the in-vivo findings, mTOR activation was also protective in isolated cardiomyocytes exposed to two models of I/R. Moreover, we identify a novel oxidant stress-activated pathway regulating mTOR that is critically dependent on p38-MAPK and Akt. This novel p38-regulated pathway signals downstream through REDD1, Tsc2, and 14-3-3 proteins to activate mTOR and is independent of AMPK. The protective role of p38/Akt and mTOR following oxidant stress is a general phenomenon since we observed it in a wide variety of cell types. Thus we have identified a novel protective pathway in the cardiomyocyte involving p38-mediated mTOR activation. Furthermore, the p38-dependent protective pathway might be able to be selectively modulated to enhance cardio-protection while not interfering with the inhibition of the better-known detrimental p38-dependent pathways.

  6. A novel cardioprotective p38-MAPK/mTOR pathway

    PubMed Central

    Hernández, Gonzalo; Lal, Hind; Fidalgo, Miguel; Guerrero, Ana; Zalvide, Juan; Force, Thomas; Pombo, Celia M.

    2011-01-01

    Despite intensive study, the mechanisms regulating activation of mTOR and the consequences of that activation in the ischemic heart remain unclear. This is particularly true for the setting of ischemia/reperfusion (I/R) injury. In a mouse model of I/R injury, we observed robust mTOR activation, and its inhibition by rapamycin increased injury. Consistent with the in-vivo findings, mTOR activation was also protective in isolated cardiomyocytes exposed to two models of I/R. Moreover, we identify a novel oxidant stress-activated pathway regulating mTOR that is critically dependent on p38-MAPK and Akt. This novel p38-regulated pathway signals downstream through REDD1, Tsc2, and 14-3-3 proteins to activate mTOR and is independent of AMPK. The protective role of p38/Akt and mTOR following oxidant stress is a general phenomenon since we observed it in a wide variety of cell types. Thus we have identified a novel protective pathway in the cardiomyocyte involving p38-mediated mTOR activation. Furthermore, the p38-dependent protective pathway might be able to be selectively modulated to enhance cardio-protection while not interfering with the inhibition of the better-known detrimental p38-dependent pathways. PMID:22001647

  7. Inhibition of p38 pathway-dependent MPTP-induced dopaminergic neurodegeneration in estrogen receptor alpha knockout mice.

    PubMed

    Hwang, Chul Ju; Choi, Dong-Young; Jung, Yu Yeon; Lee, Young-Jung; Yun, Jae Suk; Oh, Ki-Wan; Han, Sang-Bae; Oh, Seikwan; Park, Mi Hee; Hong, Jin Tae

    2016-04-01

    Approximately, 7-10 million people in the world suffer from Parkinson's disease (PD). Recently, increasing evidence has suggested the protective effect of estrogens against nigrostriatal dopaminergic damage in PD. In this study, we investigated whether estrogen affects 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced behavioral impairment in estrogen receptor alpha (ERα)-deficient mice. MPTP (15mg/kg, four times with 1.5-h interval)-induced dopaminergic neurodegeneration was evaluated in ERα wild-type (WT) and knockout (KO) mice. Larger dopamine depletion, behavioral impairments (Rotarod test, Pole test, and Gait test), activation of microglia and astrocytes, and neuroinflammation after MPTP injection were observed in ERα KO mice compared to those in WT mice. Immunostaining for tyrosine hydroxylase (TH) after MPTP injection showed fewer TH-positive neurons in ERα KO mice than WT mice. Levels of dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC, metabolite of dopamine) were also lowered in ERα KO mice after MPTP injection. Interestingly, a higher immunoreactivity for monoamine oxidase (MAO) B was found in the substantia nigra and striatum of ERα KO mice after MPTP injection. We also found an increased activation of p38 kinase (which positively regulates MAO B expression) in ERα KO mice. In vitro estrogen treatment inhibited neuroinflammation in 1-methyl-4-phenyl pyridium (MPP+)-treated cultured astrocyte cells; however, these inhibitory effects were removed by p38 inhibitor. These results indicate that ERα might be important for dopaminergic neuronal survival through inhibition of p38 pathway.

  8. Capsular Polysaccharide of Mycoplasma ovipneumoniae Induces Sheep Airway Epithelial Cell Apoptosis via ROS-Dependent JNK/P38 MAPK Pathways

    PubMed Central

    Jiang, Zhongjia; Song, Fuyang; Li, Yanan; Xue, Di; Zhao, Ning; Zhang, Jiamei; Deng, Guangcun; Li, Min

    2017-01-01

    In an attempt to better understand the pathogen-host interaction between invading Mycoplasma ovipneumoniae (M. ovipneumoniae) and sheep airway epithelial cells, biological effects and possible molecular mechanism of capsular polysaccharide of M. ovipneumoniae (CPS) in the induction of cell apoptosis were explored using sheep bronchial epithelial cells cultured in air-liquid interface (ALI). The CPS of M. ovipneumoniae was first isolated and purified. Results showed that CPS had a cytotoxic effect by disrupting the integrity of mitochondrial membrane, accompanied with an increase of reactive oxygen species and decrease of mitochondrial membrane potential (ΔΨm). Of importance, the CPS exhibited an ability to induce caspase-dependent cell apoptosis via both intrinsic and extrinsic apoptotic pathways. Mechanistically, the CPS induced extrinsic cell apoptosis by upregulating FAS/FASL signaling proteins and cleaved-caspase-8 and promoted a ROS-dependent intrinsic cell apoptosis by activating a JNK and p38 signaling but not ERK1/2 signaling of mitogen-activated protein kinases (MAPK) pathways. These findings provide the first evidence that CPS of M. ovipneumoniae induces a caspase-dependent apoptosis via both intrinsic and extrinsic apoptotic pathways in sheep bronchial epithelial cells, which may be mainly attributed by a ROS-dependent JNK and p38 MAPK signaling pathways. PMID:28367270

  9. Activation of JNK/p38 pathway is responsible for α-methyl-n-butylshikonin induced mitochondria-dependent apoptosis in SW620 human colorectal cancer cells.

    PubMed

    Wang, Hai-Bing; Ma, Xiao-Qiong

    2014-01-01

    α-Methyl-n-butylshikonin (MBS), one of the active components in the root extracts of Lithospermum erythrorhizon, posses antitumor activity. In this study, we assess the molecular mechanisms of MBS in causing apoptosis of SW620 cells. MBS reduced the cell viability of SW620 cells in a dose-and time-dependent manner and induced cell apoptosis. Treatment of SW620 cells with MBS down-regulated the expression of Bcl-2 and up-regulated the expression of Bak and caused the loss of mitochondrial membrane potential. Additionally, MBS treatment led to activation of caspase-9, caspase-8 and caspase-3, and cleavage of PARP, which was abolished by pretreatment with the pan-caspase inhibitor Z-VAD-FMK. MBS also induced significant elevation in the phosphorylation of JNK and p38. Pretreatment of SW620 cells with specific inhibitors of JNK (SP600125) and p38 (SB203580) abrogated MBS-induced apoptosis. Our results demonstrated that MBS inhibited growth of colorectal cancer SW620 cells by inducing JNK and p38 signaling pathway, and provided a clue for preclinical and clinical evaluation of MBS for colorectal cancer therapy.

  10. Piperlongumine Inhibits Migration of Glioblastoma Cells via Activation of ROS-Dependent p38 and JNK Signaling Pathways

    PubMed Central

    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 NFκB 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

  11. Chloroacetic acid induced neuronal cells death through oxidative stress-mediated p38-MAPK activation pathway regulated mitochondria-dependent apoptotic signals.

    PubMed

    Chen, Chun-Hung; Chen, Sz-Jie; Su, Chin-Chuan; Yen, Cheng-Chieh; Tseng, To-Jung; Jinn, Tzyy-Rong; Tang, Feng-Cheng; Chen, Kuo-Liang; Su, Yi-Chang; Lee, kuan-I; Hung, Dong-Zong; Huang, Chun-Fa

    2013-01-07

    Chloroacetic acid (CA), a toxic chlorinated analog of acetic acid, is widely used in chemical industries as an herbicide, detergent, and disinfectant, and chemical intermediates that are formed during the synthesis of various products. In addition, CA has been found as a by-product of chlorination disinfection of drinking water. However, there is little known about neurotoxic injuries of CA on the mammalian, the toxic effects and molecular mechanisms of CA-induced neuronal cell injury are mostly unknown. In this study, we examined the cytotoxicity of CA on cultured Neuro-2a cells and investigated the possible mechanisms of CA-induced neurotoxicity. Treatment of Neuro-2a cells with CA significantly reduced the number of viable cells (in a dose-dependent manner with a range from 0.1 to 3mM), increased the generation of ROS, and reduced the intracellular levels of glutathione depletion. CA also increased the number of sub-G1 hypodiploid cells; increased mitochondrial dysfunction (loss of MMP, cytochrome c release, and accompanied by Bcl-2 and Mcl-1 down-regulation and Bax up-regulation), and activated the caspase cascades activations, which displayed features of mitochondria-dependent apoptosis pathway. These CA-induced apoptosis-related signals were markedly prevented by the antioxidant N-acetylcysteine (NAC). Moreover, CA activated the JNK and p38-MAPK pathways, but did not that ERK1/2 pathway, in treated Neuro-2a cells. Pretreatment with NAC and specific p38-MAPK inhibitor (SB203580), but not JNK inhibitor (SP600125) effectively abrogated the phosphorylation of p38-MAPK and attenuated the apoptotic signals (including: decrease in cytotoxicity, caspase-3/-7 activation, the cytosolic cytochrome c release, and the reversed alteration of Bcl-2 and Bax mRNA) in CA-treated Neuro-2a cells. Taken together, these data suggest that oxidative stress-induced p38-MAPK activated pathway-regulated mitochondria-dependent apoptosis plays an important role in CA-caused neuronal cell

  12. 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

    2016-05-13

    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.

  13. 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

  14. 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

  15. p38 mitogen-activated protein kinase activates eNOS in endothelial cells by an estrogen receptor alpha-dependent pathway in response to black tea polyphenols.

    PubMed

    Anter, Elad; Chen, Kai; Shapira, Oz M; Karas, Richard H; Keaney, John F

    2005-05-27

    Black tea has been shown to improve endothelial function in patients with coronary artery disease and recent data indicate the polyphenol fraction of black tea enhances endothelial nitric oxide synthase (eNOS) activity through p38 MAP kinase (p38 MAPK) activation. Because the mechanisms for this phenomenon are not yet clear, we sought to elucidate the signaling events in response to black tea polyphenols. Bovine aortic endothelial cells (BAECs) exposed to black tea polyphenols demonstrated eNOS activation that was inhibited by the estrogen receptor (ER) antagonist ICI 182,780, and siRNA-mediated silencing of ER expression. Consistent with this observation, black tea polyphenols induced time-dependent phosphorylation of ERalpha on Ser-118 that was inhibited by ICI 182,780. Phosphorylation of ERalpha on Ser-118 was due to p38 MAP kinase (p38 MAPK) as, it was inhibited by SB203580 and overexpression of dominant-negative p38alpha MAPK. Conversely, constitutively active MKK6 induced p38 MAPK activation that recapitulated the effects of polyphenols by inducing ERalpha phosphorylation and downstream activation of Akt, and eNOS. The key role of ERalpha Ser-118 phosphorylation was confirmed in eNOS-transfected COS-7 cells, as polyphenol-induced eNOS activation required cotransfection with ERalpha subject to phosphorylation at Ser-118. This residue appeared critical for functional association of ERalpha with p38 MAPK as ERalpha with Ser-118 mutated to alanine could not form a complex with p38 MAPK. These findings suggest p38 MAP kinase-mediated eNOS activation requires ERalpha and these data uncover a new mechanism of ERalpha activation that has broad implications for NO bioactivity and endothelial cell phenotype.

  16. Insulin-regulated expression of Egr-1 and Krox20: dependence on ERK1/2 and interaction with p38 and PI3-kinase pathways.

    PubMed

    Keeton, Adam B; Bortoff, Katherine D; Bennett, William L; Franklin, J Lee; Venable, Derwei Y; Messina, Joseph L

    2003-12-01

    In addition to its ability to rapidly alter metabolism, insulin is also able to regulate the expression of numerous genes via activation of the PI3-kinase (PI3-K), MAPK kinase (MEK)-ERK, or p38 pathways. Using differential screening of H4IIE cells, we have identified two members of the Egr zinc-finger transcription factor family of early response genes, Egr-1 and Krox20, whose transcription is induced by insulin treatment. Egr-1 may be involved in insulin's regulation of hepatic gene expression. Krox20 regulation and expression have been primarily studied in neural cells and tissues, but little has been previously reported on the presence of Krox20 in cells of hepatic origin or its regulation by insulin. In the present studies, insulin treatment rapidly increased transcription of both Egr-1 and Krox20. In cells pretreated with a PI3-K inhibitor, there was no reduction in the effect of insulin on Egr-1 and Krox20, but an increase in Egr-1 transcription. The rapid induction of ERK1/2 phosphorylation was completely blocked by pretreatment with a MEK1 inhibitor and was associated with a nearly complete inhibition of insulin-stimulated induction of both Egr-1and Krox20, indicating this pathway is necessary for insulin's effect on these genes. Finally, inhibition of the p38 pathway, followed by insulin addition, caused an additive induction of both Egr-1and Krox20. In conclusion, these genes are induced by insulin via coordinated regulation of the MEK-ERK and p38 pathways and, in the case of Egr-1, the PI3-K pathway.

  17. 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

  18. A Stress-Activated, p38 Mitogen-Activated Protein Kinase–ATF/CREB Pathway Regulates Posttranscriptional, Sequence-Dependent Decay of Target RNAs

    PubMed Central

    Gao, Jun; Wagnon, Jacy L.; Protacio, Reine M.; Glazko, Galina V.; Beggs, Marjorie; Raj, Vinay

    2013-01-01

    Broadly conserved, mitogen-activated/stress-activated protein kinases (MAPK/SAPK) of the p38 family regulate multiple cellular processes. They transduce signals via dimeric, basic leucine zipper (bZIP) transcription factors of the ATF/CREB family (such as Atf2, Fos, and Jun) to regulate the transcription of target genes. We report additional mechanisms for gene regulation by such pathways exerted through RNA stability controls. The Spc1 (Sty1/Phh1) kinase-regulated Atf1-Pcr1 (Mts1-Mts2) heterodimer of the fission yeast Schizosaccharomyces pombe controls the stress-induced, posttranscriptional stability and decay of sets of target RNAs. Whole transcriptome RNA sequencing data revealed that decay is associated nonrandomly with transcripts that contain an M26 sequence motif. Moreover, the ablation of an M26 sequence motif in a target mRNA is sufficient to block its stress-induced loss. Conversely, engineered M26 motifs can render a stable mRNA into one that is targeted for decay. This stress-activated RNA decay (SARD) provides a mechanism for reducing the expression of target genes without shutting off transcription itself. Thus, a single p38-ATF/CREB signal transduction pathway can coordinately induce (promote transcription and RNA stability) and repress (promote RNA decay) transcript levels for distinct sets of genes, as is required for developmental decisions in response to stress and other stimuli. PMID:23732911

  19. p38 and JNK pathways control E-selectin-dependent extravasation of colon cancer cells by modulating miR-31 transcription

    PubMed Central

    Zhong, Liang; Simoneau, Bryan; Huot, Jacques; Simard, Martin J.

    2017-01-01

    Extravasation of circulating cancer cells is a key event of metastatic dissemination that is initiated by the adhesion of cancer cells to vascular endothelial cells. It requires the interaction between adhesion receptors such as E-selectin present on endothelial cells and their ligands on cancer cells. Notably, E-selectin influences the metastatic potential of breast, bladder, gastric, pancreatic, and colorectal carcinoma as well as of leukemia and lymphoma. Here, we show that E-selectin expression induced by the pro-inflammatory cytokine IL-1β is directly and negatively regulated by miR-31. The transcription of miR-31 is activated by IL-1β. This activation depends on p38 and JNK MAP kinases, and their downstream transcription factors GATA2, c-Fos and c-Jun. The miR-31-mediated repression of E-selectin impairs the metastatic potential of colon cancer cells by decreasing their adhesion to, and migration through, the endothelium. These results highlight for the first time that microRNA mediates E-selectin-dependent extravasation of colon cancer cells. PMID:27926494

  20. 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

  1. Down-regulation of MMP-2 through the p38 MAPK-NF-kappaB-dependent pathway by aloe-emodin leads to inhibition of nasopharyngeal carcinoma cell invasion.

    PubMed

    Lin, Meng-Liang; Lu, Yao-Cheng; Chung, Jing-Gung; Wang, Shyang-Guang; Lin, Hsin-Ting; Kang, Shang-En; Tang, Chih-Hsin; Ko, Jiunn-Liang; Chen, Shih-Shun

    2010-09-01

    Aloe-emodin (AE), extracted from the rhizome of Rheum palmatum, has an anti-proliferative effect on different human cancer cell lines. Nonetheless, the underlying mechanism by which AE inhibits nasopharyngeal carcinoma (NPC) cell invasion is still unclear. The results of this study show that treatment of NPC cells with growth suppressive concentrations of AE caused cell cycle arrest at the S-G(2)/M phase. Coimmunoprecipitation and small interfering RNA (siRNA) studies demonstrated that AE-induced cell cycle arrest in NPC cells was associated with increasing levels of cyclin B1 bound to cyclin-dependent kinase 1. The inhibition of NPC cell invasion by AE was evidenced through the suppression of matrix metalloproteinases-2 (MMP-2) expression. MMP-2 promoter activity and cell invasion were inhibited by p38 mitogen-activated protein kinase (MAPK) siRNA, inhibitor 4-(4-Fluorophenyl)-2-[4-(methylsulfinyl)phenyl]-5-(4-pyridyl)-1H-imidazole (SB203580), and AE, but not by JNK siRNA and inhibitor 1,9-pyrazoloanthrone. Treatment with AE, SB203580, NF-kappaB inhibitors N-p-tosyl-(L)-phenylalanine chloromethyl ketone (TPCK) and pyrrolidine dithiocarbamate (PDTC) or transfection with p38 MAPK siRNA significantly inhibited NF-kappaB transcriptional activity. In addition, TPCK and PDTC treatment inhibited the expression and promoter activity of MMP-2 and thereby significantly inhibited cell invasion activity. The involvement of p38 MAPK activity in NF-kappaB-mediated MMP-2 function was further confirmed through the attenuation of p38 MAPK by SB203580 and NF-kappaB ectopic expression. Collectively, our results indicate that AE inhibits invasion of NPC cells by suppressing the expression of MMP-2 via the p38 MAPK-NF-kappaB signaling pathway.

  2. Beta Interferon Production Is Regulated by p38 Mitogen-Activated Protein Kinase in Macrophages via both MSK1/2- and Tristetraprolin-Dependent Pathways

    PubMed Central

    McGuire, Victoria A.; Rosner, Dalya; Ananieva, Olga; Ross, Ewan A.; Elcombe, Suzanne E.; Naqvi, Shaista; van den Bosch, Mirjam M. W.; Monk, Claire E.; Ruiz-Zorrilla Diez, Tamara; Clark, Andrew R.

    2016-01-01

    ABSTRACT Autocrine or paracrine signaling by beta interferon (IFN-β) is essential for many of the responses of macrophages to pathogen-associated molecular patterns. This feedback loop contributes to pathological responses to infectious agents and is therefore tightly regulated. We demonstrate here that macrophage expression of IFN-β is negatively regulated by mitogen- and stress-activated kinases 1 and 2 (MSK1/2). Lipopolysaccharide (LPS)-induced expression of IFN-β was elevated in both MSK1/2 knockout mice and macrophages. Although MSK1 and -2 promote the expression of the anti-inflammatory cytokine interleukin 10, it did not strongly contribute to the ability of MSKs to regulate IFN-β expression. Instead, MSK1 and -2 inhibit IFN-β expression via the induction of dual-specificity phosphatase 1 (DUSP1), which dephosphorylates and inactivates the mitogen-activated protein kinases p38 and Jun N-terminal protein kinase (JNK). Prolonged LPS-induced activation of p38 and JNK, phosphorylation of downstream transcription factors, and overexpression of IFN-β mRNA and protein were similar in MSK1/2 and DUSP1 knockout macrophages. Two distinct mechanisms were implicated in the overexpression of IFN-β: first, JNK-mediated activation of c-jun, which binds to the IFN-β promoter, and second, p38-mediated inactivation of the mRNA-destabilizing factor tristetraprolin, which we show is able to target the IFN-β mRNA. PMID:27795299

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  5. p38 pathway targets SWI-SNF chromatin-remodeling complex to muscle-specific loci.

    PubMed

    Simone, Cristiano; Forcales, Sonia Vanina; Hill, David A; Imbalzano, Anthony N; Latella, Lucia; Puri, Pier Lorenzo

    2004-07-01

    During skeletal myogenesis, genomic reprogramming toward terminal differentiation is achieved by recruiting chromatin-modifying enzymes to muscle-specific loci. The relative contribution of extracellular signaling cascades in targeting these enzymes to individual genes is unknown. Here we show that the differentiation-activated p38 pathway targets the SWI-SNF chromatin-remodeling complex to myogenic loci. Upon differentiation, p38 kinases were recruited to the chromatin of muscle-regulatory elements. Blockade of p38 alpha/beta repressed the transcription of muscle genes by preventing recruitment of the SWI-SNF complex at these elements without affecting chromatin binding of muscle-regulatory factors and acetyltransferases. The SWI-SNF subunit BAF60 could be phosphorylated by p38 alpha-beta in vitro, and forced activation of p38 alpha/beta in myoblasts by expression of a constitutively active MKK6 (refs. 5,6,7) promoted unscheduled SWI-SNF recruitment to the myogenin promoter. Conversely, inactivation of SWI-SNF enzymatic subunits abrogated MKK6-dependent induction of muscle gene expression. These results identify an unexpected function of differentiation-activated p38 in converting external cues into chromatin modifications at discrete loci, by selectively targeting SWI-SNF to muscle-regulatory elements.

  6. Endoplasmic reticulum stress-mediated apoptosis of EBV-transformed B cells by cross-linking of CD70 is dependent upon generation of reactive oxygen species and activation of p38 MAPK and JNK pathway.

    PubMed

    Park, Ga Bin; Kim, Yeong Seok; Lee, Hyun-Kyung; Song, Hyunkeun; Cho, Dae-Ho; Lee, Wang Jae; Hur, Dae Young

    2010-12-15

    CD70 is expressed in normal activated immune cells as well as in several types of tumors. It has been established that anti-CD70 mAb induces complement-dependent death of CD70(+) tumor cells, but how anti-CD70 mAb affects the intrinsic signaling is poorly defined. In this report, we show that ligation of CD70 expressed on EBV-transformed B cells using anti-CD70 mAb induced production of reactive oxygen species (ROS) and subsequent apoptosis. We observed an early expression of endoplasmic reticulum (ER) stress response genes that preceded the release of apoptotic molecules from the mitochondria and the cleavage of caspases. CD70-induced apoptosis was inhibited by pretreatment with the ER stress inhibitor salubrinal, ROS quencher N-acetylcysteine, and Ca(2+) chelator BAPTA. We supposed that ROS generation might be the first event of CD70-induced apoptosis because N-acetylcysteine blocked increases of ROS and Ca(2+), but BAPTA did not block ROS generation. We also found that CD70 stimulation activated JNK and p38 MAPK. JNK inhibitor SP600125 and p38 inhibitor SB203580 effectively blocked upregulation of ER stress-related genes and cleavage of caspases. Inhibition of ROS generation completely blocked phosphorylation of JNK and p38 MAPK and induction of ER stress-related genes. Taken together, we concluded that cross-linking of CD70 on EBV-transformed B cells triggered ER stress-mediated apoptosis via ROS generation and JNK and p38 MAPK pathway activation. Our report reveals alternate mechanisms of direct apoptosis through CD70 signaling and provides data supporting CD70 as a viable target for an Ab-based therapy against EBV-related tumors.

  7. Lipopolysaccharide: a p38 MAPK-dependent disrupter of neutrophil chemotaxis.

    PubMed

    Khan, Adil I; Heit, Bryan; Andonegui, Graciela; Colarusso, Pina; Kubes, Paul

    2005-01-01

    In sepsis, and in models of sepsis including endotoxemia, impaired neutrophil recruitment and chemotaxis have been reported. The inability of the endotoxemic neutrophil to chemotax could be attributed to the fact that intracellular signaling via LPS overrides signals from endogenous chemokines or, alternatively, that sequestration of neutrophils into lungs prevents access to peripheral tissues. Using both in vitro and in vivo chemotaxis assays the authors established that neutrophils from healthy mice chemotaxed in vivo toward MIP-2, whereas endotoxemic neutrophils did not. Since LPS activates leukocytes via the p38 MAPK pathway, SKF86002, a p38 MAPK inhibitor, was given to endotoxemic animals. SKF86002 significantly reversed the LPS-induced impairment in emigration of endotoxic neutrophils in response to MIP-2. Neutrophil chemotaxis in vitro was also impaired by LPS, via a p38 MAPK-dependent pathway, and this impairment could be reversed via p38 MAPK inhibition. Although neutrophil numbers dropped in the circulation and trapped in lungs during endotoxemia, SKF86002 did not reverse these parameters, demonstrating that p38 MAPK inhibition did not release trapped neutrophils from the lungs. In conclusion, the data suggest that the impaired emigration and chemotaxis of neutrophils at peripheral sites during endotoxemia may be partially due to a p38 MAPK-mediated inhibition of neutrophil responses to endogenous chemokines.

  8. 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

    2015-10-02

    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.

  9. An evolutionarily conserved Rit GTPase–p38 MAPK signaling pathway mediates oxidative stress resistance

    PubMed Central

    Cai, Weikang; Rudolph, Jennifer L.; Harrison, Susan M. W.; Jin, Ling; Frantz, Aubrey L.; Harrison, Douglas A.; Andres, Douglas A.

    2011-01-01

    Ras-related small GTP-binding proteins control a wide range of cellular processes by regulating a variety of effector pathways, including prominent roles in the control of mitogen-activated protein kinase (MAPK) cascades. Although the regulatory role(s) for many Ras family GTPases are well established, the physiological function for the Rit/Rin subfamily has been lacking. Here, using both knockout mice and Drosophila models, we demonstrate an evolutionarily conserved role for Rit subfamily GTPases (mammalian Rit and Rin, and the Drosophila RIC homologue) in governing survival in response to oxidative stress. Primary embryonic fibroblasts derived from Rit knockout mice display increased apoptosis and selective disruption of MAPK signaling following reactive oxygen species (ROS) exposure but not in response to endoplasmic reticulum stress or DNA damage. These deficits include a reduction in ROS-mediated stimulation of a p38-MK2-HSP27 signaling cascade that controls Akt activation, directing Bad phosphorylation to promote cell survival. Furthermore, D-RIC null flies display increased susceptibility to environmental stresses and reduced stress-dependent p38 signaling, extending the Rit-p38 survival pathway to Drosophila. Together, our studies establish the Rit GTPases as critical regulators of an evolutionarily conserved, p38 MAPK–dependent signaling cascade that functions as an important survival mechanism for cells in response to oxidative stress. PMID:21737674

  10. 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.

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

    PubMed Central

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

    2015-01-01

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

  12. CREB is activated by UVC through a p38/HOG-1-dependent protein kinase.

    PubMed Central

    Iordanov, M; Bender, K; Ade, T; Schmid, W; Sachsenmaier, C; Engel, K; Gaestel, M; Rahmsdorf, H J; Herrlich, P

    1997-01-01

    Changes in environmental conditions such as the addition of growth factors or irradiation of cells in culture first affect immediate response genes. We have shown previously that short wavelength UV irradiation (UVC) elicits massive activation of several growth factor receptor-dependent pathways. At the level of the immediate response gene c-fos, these pathways activate the transcription factor complex serum response factor (SRF)-p62TCF which mediates part of the UV-induced transcriptional response. These studies have, however, suggested that more that one pathway is required for full UV responsiveness of c-fos. Using appropriate promoter mutations and dominant-negative cAMP response element (CRE)-binding protein (CREB), we now find that UVC-induced transcriptional activation depends also on the CRE at position -60 of the c-fos promoter and on the functionality of a CREB. Upon UV irradiation, CREB and ATF-1 are phosphorylated at serines 133 and 63, respectively, preceded by and dependent on activation of p38/RK/HOG-1 and of a p38/RK/HOG-1-dependent p108 CREB kinase. Although p90RSK1 and MAPKAP kinase 2 are also activated by UV, p90RSK1 does not, at least not decisively, participate in this signalling pathway to CREB and ATF-1 as it is not p38/RK/HOG-1 dependent, and CREB is a poor substrate for MAPKAP kinase 2 in vitro. On the basis of resistance to the growth factor receptor inhibitor suramin and of several types of cross-refractoriness experiments, the UVC-induced CREB/ATF-1 phosphorylation represents an as yet unrecognized route of UVC-induced signal transduction, independent of suramin-inhibitable growth factor receptors and different from the Erk 1,2-p62TCF pathway. PMID:9118940

  13. 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.

  14. Targeting the p38 MAPK pathway inhibits irinotecan resistance in colon adenocarcinoma.

    PubMed

    Paillas, Salomé; Boissière, Florence; Bibeau, Fréderic; Denouel, Amélie; Mollevi, Caroline; Causse, Annick; Denis, Vincent; Vezzio-Vié, Nadia; Marzi, Laetitia; Cortijo, Cédric; Ait-Arsa, Imade; Askari, Nadav; Pourquier, Philippe; Martineau, Pierre; Del Rio, Maguy; Gongora, Céline

    2011-02-01

    Despite recent advances in the treatment of colon cancer, tumor resistance is a frequent cause of chemotherapy failure. To better elucidate the molecular mechanisms involved in resistance to irinotecan (and its active metabolite SN38), we established SN38-resistant clones derived from HCT-116 and SW48 cell lines. These clones show various levels (6- to 60-fold) of resistance to SN-38 and display enhanced levels of activated MAPK p38 as compared with the corresponding parental cells. Because four different isoforms of p38 have been described, we then studied the effect of p38 overexpression or downregulation of each isoform on cell sensivity to SN38 and found that both α and β isoforms are involved in the development of resistance to SN38. In this line, we show that cell treatment with SB202190, which inhibits p38α and p38β, enhanced the cytotoxic activity of SN38. Moreover, p38 inhibition sensitized tumor cells derived from both SN38-sensitive and -resistant HCT116 cells to irinotecan treatment in xenograft models. Finally, we detected less phosphorylated p38 in primary colon cancer of patients sensitive to irinotecan-based treatment, compared with nonresponder patients. This indicates that enhanced level of phosphorylated p38 could predict the absence of clinical response to irinotecan. Altogether, our results show that the p38 MAPK pathway is involved in irinotecan sensitivity and suggest that phosphorylated p38 expression level could be used as a marker of clinical resistance to irinotecan. They further suggest that targeting the p38 pathway may be a potential strategy to overcome resistance to irinotecan-based chemotherapies in colorectal cancer.

  15. 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.

  16. 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

  17. Induction of apoptosis by quercetin is mediated through AMPKalpha1/ASK1/p38 pathway.

    PubMed

    Lee, Yun-Kyoung; Hwang, Jin-Taek; Kwon, Dae Young; Surh, Young-Joon; Park, Ock Jin

    2010-06-28

    Effective strategies for cancer prevention and treatment can be identified by understanding the mechanism of apoptotic pathways. In this study, we investigated the regulatory mechanism of quercetin-induced apoptosis through apoptosis signal-regulating kinase (ASK)-1 and mitogen-activated protein kinase pathways. Our results showed that quercetin increased apoptotic cell death through reactive oxygen species (ROS) generation and was responsible for ASK1 activation. Increasing ASK1 activity was accompanied by p38 activation. Interestingly, AMP-activated protein kinase (AMPK) seemed to be a critical controller of quercetin-regulated ASK1/p38 activation. Blocking AMPKalpha1 activity using Compound C, a synthetic inhibitor or siRNA showed that quercetin-activated ASK1 could not stimulate p38 activity. Thus, we suggested that quercetin-exerted apoptotic effects involve ROS/AMPKalpha1/ASK1/p38 signaling pathway, and AMPKalpha1 is a necessary element for apoptotic event induced by ASK1.

  18. Sunlight UV-induced skin cancer relies upon activation of the p38α signaling pathway.

    PubMed

    Liu, Kangdong; Yu, Donghoon; Cho, Yong-Yeon; Bode, Ann M; Ma, Weiya; Yao, Ke; Li, Shengqing; Li, Jixia; Bowden, G Tim; Dong, Ziming; Dong, Zigang

    2013-04-01

    The activation of cellular signal transduction pathways by solar ultraviolet (SUV) irradiation plays a vital role in skin tumorigenesis. Although many pathways have been studied using pure ultraviolet A (UVA) or ultraviolet B (UVB) irradiation, the signaling pathways induced by SUV (i.e., sunlight) are not understood well enough to permit improvements for prevention, prognosis, and treatment. Here, we report parallel protein kinase array studies aimed at determining the dominant signaling pathway involved in SUV irradiation. Our results indicated that the p38-related signal transduction pathway was dramatically affected by SUV irradiation. SUV (60 kJ UVA/m(2)/3.6 kJ UVB/m(2)) irradiation stimulates phosphorylation of p38α (MAPK14) by 5.78-fold, MSK2 (RPS6KA4) by 6.38-fold, and HSP27 (HSPB1) by 34.56-fold compared with untreated controls. By investigating the tumorigenic role of SUV-induced signal transduction in wild-type and p38 dominant-negative (p38 DN) mice, we found that p38 blockade yielded fewer and smaller tumors. These results establish that p38 signaling is critical for SUV-induced skin carcinogenesis.

  19. 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

  20. Epidermal growth factor-stimulated intestinal epithelial cell migration requires Src family kinase-dependent p38 MAPK signaling.

    PubMed

    Frey, Mark R; Golovin, Anastasia; Polk, D Brent

    2004-10-22

    Members of the epidermal growth factor (EGF) family of ligands and their receptors regulate migration and growth of intestinal epithelial cells. However, our understanding of the signal transduction pathways determining these responses is incomplete. In this study we tested the hypothesis that p38 is required for EGF-stimulated intestinal epithelial monolayer restitution. EGF-stimulated migration in a wound closure model required continuous presence of ligand for several hours for maximal response, suggesting a requirement for sustained signal transduction pathway activation. In this regard, prolonged exposure of cells to EGF activated p38 for up to 5 h. Furthermore genetic or pharmacological blockade of p38 signaling inhibited the ability of EGF to accelerate wound closure. Interestingly p38 inhibition was associated with increased EGF-stimulated ERK1/ERK2 phosphorylation and cell proliferation, suggesting that p38 regulates the balance of proliferation/migration signaling in response to EGF receptor activity. Activation of p38 in intestinal epithelial cells through EGF receptor was abolished by blockade of Src family tyrosine kinase signaling but not inhibition of phosphatidylinositol 3-kinase or protein kinase C. Taken together, these data suggest that Src family kinase-dependent p38 activation is a key component of a signaling switch routing EGF-stimulated responses to epithelial cell migration/restitution rather than proliferation during wound closure.

  1. Osmotic stress inhibits proteasome by p38 MAPK-dependent phosphorylation.

    PubMed

    Lee, Seung-Hoon; Park, Yoon; Yoon, Sungjoo Kim; Yoon, Jong-Bok

    2010-12-31

    Osmotic stress causes profound perturbations of cell functions. Although the adaptive responses required for cell survival upon osmotic stress are being unraveled, little is known about the effects of osmotic stress on ubiquitin-dependent proteolysis. We now report that hyperosmotic stress inhibits proteasome activity by activating p38 MAPK. Osmotic stress increased the level of polyubiquitinated proteins in the cell. The selective p38 inhibitor SB202190 decreased osmotic stress-associated accumulation of polyubiquitinated proteins, indicating that p38 MAPK plays an inhibitory role in the ubiquitin proteasome system. Activated p38 MAPK stabilized various substrates of the proteasome and increased polyubiquitinated proteins. Proteasome preparations purified from cells expressing activated p38 MAPK had substantially lower peptidase activities than control proteasome samples. Proteasome phosphorylation sites dependent on p38 were identified by measuring changes in the extent of proteasome phosphorylation in response to p38 MAPK activation. The residue Thr-273 of Rpn2 is the major phosphorylation site affected by p38 MAPK. The mutation T273A in Rpn2 blocked the proteasome inhibition that is mediated by p38 MAPK. These results suggest that p38 MAPK negatively regulates the proteasome activity by phosphorylating Thr-273 of Rpn2.

  2. Angiotensin II limits NO production by upregulating arginase through a p38 MAPK - ATF-2 pathway

    PubMed Central

    Shatanawi, Alia; Lemtalsi, Tahira; Yao, Lin; Patel, Chintan; Caldwell, Ruth B.; Caldwell, R. William

    2014-01-01

    Enhanced vascular arginase activity can impair endothelium-dependent vasorelaxation by decreasing L-arginine availability to endothelial nitric oxide (NO) synthase, thereby reducing NO production and uncoupling NOS function. Elevated angiotensin II (Ang II) is a key component of endothelial dysfunction in many cardiovascular diseases and has been linked to elevated arginase activity. In this study we explored the signaling pathway leading to increased arginase expression/activity in response to Ang II in bovine aortic endothelial cells (BAEC). Our previous studies indicate involvement of p38 mitogen activated protein kinase (MAPK) in Ang II-induced arginase upregulation and reduced NO production. In this study, we further investigated the Ang II-transcriptional regulation of arginase 1 in endothelial cells. Our results indicate the involvement of ATF-2 transcription factor of the AP1 family in arginase 1 upregulation and in limiting NO production. Using small interfering RNA (siRNA) targeting ATF-2, we showed that this transcription factor is required for Ang II-induced arginase 1 gene upregulation and increased arginase 1 expression and activity, leading to reduced NO production. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay further confirmed the involvement of ATF-2. Moreover, our data indicate that p38 MAPK phosphorylates ATF-2 in response to Ang II. Collectively, our results indicate that Ang II increases endothelial arginase activity/expression through a p38 MAPK/ATF-2 pathway leading to reduced endothelial NO production. These signaling steps might be therapeutic targets for preventing vascular endothelial dysfunction associated with elevated arginase activity/expression. PMID:25446432

  3. 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

  4. The p38 mitogen-activated protein kinase (MAPK) pathway in rheumatoid arthritis

    PubMed Central

    Schett, G; Zwerina, J; Firestein, G

    2009-01-01

    Chronic inflammatory processes are based on a sustained and tightly regulated communication network among different cells types. This network comprises extracellular mediators such as cytokines, chemokines and matrix-degrading proteases, which orchestrate the participation of cells in the chronic inflammatory process. The mirrors of this outside communication world are intracellular transcription factor pathways, which shuttle information about inflammatory stimuli to the cell nucleus. This review examines the function of one key signal transduction pathway of inflammation—the p38 mitogen-activated protein kinases (p38MAPK). The signalling pathway is considered as crucial for the induction and maintenance of chronic inflammation, and its components thus emerge as interesting molecular targets of small molecule inhibitors for controlling inflammation. This review not only summarises the current knowledge of activation, regulation and function of the p38MAPK pathway but also examines the role of this pathway in clinical disease. It gives an overview of current evidence of p38MAPK activation in inflammatory arthritis and elaborates the key molecular determinants which contribute to p38MAPK activation in joint disease. PMID:17827184

  5. The p38 MAPK Pathway in Rheumatoid Arthritis: A Sideways Look

    PubMed Central

    Clark, Andrew R; Dean, Jonathan LE

    2012-01-01

    The p38 mitogen-activated protein kinase (MAPK) signaling pathway has been strongly implicated in many of the processes that underlie the pathology of rheumatoid arthritis (RA). For many years it has been considered a promising target for development of new anti-inflammatory drugs with which to treat RA and other chronic immune-mediated inflammatory diseases. However, several recent clinical trials have concluded in a disappointing manner. Why is this so, if p38 MAPK clearly contributes to the excessive production of inflammatory mediators, the destruction of bone and cartilage? We argue that, to explain the apparent failure of p38 inhibitors in the rheumatology clinic, we need to understand better the complexities of the p38 pathway and its many levels of communication with other cellular signaling pathways. In this review we look at the p38 MAPK pathway from a slightly different perspective, emphasising its role in post-transcriptional rather than transcriptional control of gene expression, and its contribution to the off-phase rather than the on-phase of the inflammatory response. PMID:23028406

  6. 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

  7. Moderate endoplasmic reticulum stress activates a PERK and p38-dependent apoptosis.

    PubMed

    Lumley, Emily C; Osborn, Acadia R; Scott, Jessica E; Scholl, Amanda G; Mercado, Vicki; McMahan, Young T; Coffman, Zachary G; Brewster, Jay L

    2017-01-01

    The endoplasmic reticulum (ER) has the ability to signal organelle dysfunction via a complex signaling network known as the unfolded protein response (UPR). In this work, hamster fibroblast cells exhibiting moderate levels of ER stress were compared to those exhibiting severe ER stress. Inhibition of N-linked glycosylation was accomplished via a temperature-sensitive mutation in the Dad1 subunit of the oligosaccharyltransferase (OST) complex or by direct inhibition with tunicamycin (Tm). Temperature shift (TS) treatment generated weak activation of ER stress signaling when compared to doses of Tm that are typically used in ER stress studies (500-1000 nM). A dose-response analysis of key ER stress signaling mediators, inositol-requiring enzyme 1 (IRE1) and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), revealed 20-40 nM of Tm to generate activation intensity similar to TS treatment. In parental BHK21 cells, moderate (20-40 nM) and high doses (200-1000 nM) of Tm were compared to identify physiological and signaling-based differences in stress response. Inhibition of ER Ca(2+) release via ITPR activity with 2-aminoethoxydiphenyl borate (2-APB) or Xestospongin C (XeC) was sufficient to protect against apoptosis induced by moderate but not higher doses of Tm. Analysis of kinase activation over a range of Tm exposures revealed the p38 stress-activated protein kinase (SAPK) to display increasing activation with Tm dosage. Interestingly, Tm induced the extracellular regulated kinases (Erk1/2) only at moderate doses of Tm. Inhibition of ER transmembrane stress sensors (IRE1, PERK) or cytosolic signaling mediators (p38, Jnk1, Erk1/2) was used to evaluate pathways involved in apoptosis activation during ER stress. Inhibition of either PERK or p38 was sufficient to reduce cell death and apoptosis induced by moderate, but not high, doses of Tm. During ER stress, cells exhibited a rapid decline in anti-apoptotic Mcl-1 and survivin proteins. Inhibition of

  8. Role of p38 MAPK pathway in 17β-estradiol-mediated attenuation of hemorrhagic shock-induced hepatic injury.

    PubMed

    Hsu, Jun-Te; Chen, Tsung-Hsing; Chiang, Kun-Chun; Kuo, Chia-Jung; Lin, Chun-Jung; Yeh, Ta-Sen

    2015-01-15

    Although 17β-estradiol (E2) treatment following hemorrhagic shock or ischemic reperfusion prevents organs from dysfunction and injury, the precise mechanism remains unknown. We hypothesize that the E2-mediated attenuation of liver injury following hemorrhagic shock and fluid resuscitation occurs via the p38 mitogen-activated protein kinase (MAPK)-dependent heme oxygenase (HO)-1 pathway. After a 5-cm midline laparotomy, male rats underwent hemorrhagic shock (mean blood pressure ∼40 mmHg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, E2 (1 mg/kg) alone, or E2 plus p38 MAPK inhibitor SB-203580 (2 mg/kg), HO-1 inhibitor chromium mesoporphyrin-IX chloride (2.5 mg/kg) or estrogen receptor antagonist ICI 182,780 (3 mg/kg). At 2 h after hemorrhagic shock and fluid resuscitation, the liver injury markers were significantly increased compared with sham-operated control. Hemorrhagic shock resulted in a significant decrease in p38 MAPK phosphorylation compared with the shams. Administration of E2 following hemorrhagic shock normalized liver p38 MAPK phosphorylation, further increased HO-1 expression, and reduced cleaved caspase-3 levels. Coadministration of SB-203580 abolished the E2-mediated attenuation of the shock-induced liver injury markers. In addition, administration of chromium mesoporphyrin-IX chloride or ICI 182,780 abolished E2-mediated increases in liver HO-1 expression or p38 MAPK activation following hemorrhagic shock. Our results collectively suggest that the salutary effects of E2 on hepatic injury following hemorrhagic shock and resuscitation are in part mediated through an estrogen-receptor-related p38 MAPK-dependent HO-1 upregulation.

  9. Endotoxin promotes neutrophil hierarchical chemotaxis via the p38-membrane receptor pathway

    PubMed Central

    Wang, Xu; Qin, Weiting; Zhang, Yisen; Zhang, Huafeng; Sun, Bingwei

    2016-01-01

    Neutrophils are the most abundant leukocytes in peripheral blood and play critical a role in bacterial infection, tumor immunity and wound repair. Clarifying the process of neutrophil chemotaxis to target sites of immune activity has been a focus of increased interest within the past decade. In bacterial infectious foci, neutrophils migrate toward the bacterial-derived chemoattractant N-formyl-Met-Leu-Phe (fMLP) and ignore other intermediary chemoattractants to arrive at the area of infection. Using an under agarose chemotaxis assay, we observed that the bacterial fMLP-induced neutrophil chemotaxis signal overrode interleukin 8 (IL-8)- and leukotriene B4 (LTB4)-induced chemotaxis signals. Moreover, in the presence of bacterial lipopolysaccharide (LPS), the fMLP-induced hierarchical chemotaxis signal was enhanced. Further studies revealed that LPS increased the membrane expression of the fMLP receptor, formyl peptide receptor 1 (FPR1). However, expression levels of the membrane receptors for IL-8 and LTB4 were decreased by LPS administration. A human Phospho-mitogen-activated protein kinase (MAPK) proteome array showed that the p38 pathway was significantly activated by LPS stimulation. Moreover, p38 was responsible for the altered expression of neutrophil membrane chemoattractant receptors. Inhibition of neutrophil p38 restored LPS-improved hierarchical chemotaxis. Taken together, these data indicate that endotoxin promotes neutrophil hierarchical chemotaxis via the p38-membrane receptor pathway. PMID:27655676

  10. Comparative analysis of regulatory roles of P38 signaling pathway in 8 types liver cell during liver regeneration.

    PubMed

    Yang, Xianguang; Zhu, Lin; Zhao, Weiming; Shi, Yaohuang; He, Chuncui; Xu, Cunshuan

    2016-12-05

    P38MAPK signaling pathway was closely related to cell proliferation, apoptosis, cell differentiation, cell survival, cell death, and so on. However, the regulatory mechanism of P38MAPK signaling pathway in liver regeneration (LR) was unclear. In order to further reveal the roles of P38MAPK signaling pathway in rat liver regeneration, Ingenuity Pathway Analysis (IPA) software and related data sites were used to construct P38MAPK signaling pathway, and the pathway was confirmed by relevant documents literature. The expression changes of P38MAPK signaling pathway-related gene in eight type cells were further analyzed by Rat Genome 230 2.0 Array, and the results showed that 95 genes in P38MAPK signaling pathway had significant changes. H-cluster analysis showed that hepatocyte cell (HC), pit cell (PC), oval cell (OC) and biliary epithelial cell (BEC) are clustered together; and the same as Kupffer cell (KC), sinusoidal endothelial cell (SEC), dendritic cell (DC) and hepatic stellate cell (HSC). IPA software and expression analysis systematic explorer (EASE) were applied to functional enrichment analysis, and the results showed that P38MAPK signaling pathway was mainly involved in apoptosis, cell death, cell proliferation, cell survival, cell viability, activation, cell cycle progression, necrosis, synthesis of DNA and other physical activity during LR. In conclusion, P38MAPK signaling pathway regulated various physiological activities of LR through multiple signaling pathways.

  11. 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

  12. Glial activation in the periaqueductal gray promotes descending facilitation of neuropathic pain through the p38 MAPK signaling pathway.

    PubMed

    Ni, Hua-Dong; Yao, Ming; Huang, Bing; Xu, Long-Sheng; Zheng, Ying; Chu, Yu-Xia; Wang, Han-Qi; Liu, Ming-Juan; Xu, Shi-Jie; Li, Hong-Bo

    2016-01-01

    The midbrain ventrolateral periaqueductal gray (VL-PAG) is a key component that mediates pain modulation. Although spinal cord glial cells appear to play an important role in chronic pain development, the precise mechanisms involving descending facilitation pathways from the PAG following nerve injury are poorly understood. This study shows that cellular events that occur during glial activation in the VL-PAG may promote descending facilitation from the PAG during neuropathic pain. Chronic constriction nerve injury (CCI) was induced by ligature construction of the sciatic nerve in male Sprague-Dawley rats. Behavioral responses to noxious mechanical (paw withdrawal threshold; PWT) and thermal (paw withdrawal latency; PWL) stimuli were evaluated. After CCI, immunohistochemical and Western blot analysis of microglia and astrocytes in the VL-PAG showed morphological and quantitative changes indicative of activation in microglia and astrocytes. Intra-VL-PAG injection of microglial or astrocytic inhibitors attenuated PWT and PWL at days 7 and 14, respectively, following CCI. We also evaluated the effects of intra-VL-PAG administration of the phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) inhibitor SB 203580 at day 7 after CCI. This treatment abolished microglial activation and produced a significant time-dependent attenuation of PWT and PWL. Western blot analysis showed localized expression of p-p38 in the VL-PAG after CCI. P-p38 was expressed in labeled microglia of the VL-PAG but was not present in astrocytes and neurons on day 7 after CCI. These results demonstrate that CCI-induced neuropathic pain is associated with glial activation in the VL-PAG, which likely participates in descending pain facilitation through the p38 MAPK signaling pathway.

  13. Cross Talk between the Akt and p38α Pathways in Macrophages Downstream of Toll-Like Receptor Signaling

    PubMed Central

    McGuire, Victoria A.; Gray, Alexander; Monk, Claire E.; Santos, Susana G.; Lee, Keunwook; Aubareda, Anna; Crowe, Jonathan; Ronkina, Natalia; Schwermann, Jessica; Batty, Ian H.; Leslie, Nick R.; Dean, Jonathan L. E.; O'Keefe, Stephen J.; Boothby, Mark; Gaestel, Matthias

    2013-01-01

    The stimulation of Toll-like receptors (TLRs) on macrophages by pathogen-associated molecular patterns (PAMPs) results in the activation of intracellular signaling pathways that are required for initiating a host immune response. Both phosphatidylinositol 3-kinase (PI3K)–Akt and p38 mitogen-activated protein kinase (MAPK) signaling pathways are activated rapidly in response to TLR activation and are required to coordinate effective host responses to pathogen invasion. In this study, we analyzed the role of the p38-dependent kinases MK2/3 in the activation of Akt and show that lipopolysaccharide (LPS)-induced phosphorylation of Akt on Thr308 and Ser473 requires p38α and MK2/3. In cells treated with p38 inhibitors or an MK2/3 inhibitor, phosphorylation of Akt on Ser473 and Thr308 is reduced and Akt activity is inhibited. Furthermore, BMDMs deficient in MK2/3 display greatly reduced phosphorylation of Ser473 and Thr308 following TLR stimulation. However, MK2/3 do not directly phosphorylate Akt in macrophages but act upstream of PDK1 and mTORC2 to regulate Akt phosphorylation. Akt is recruited to phosphatidylinositol 3,4,5-trisphosphate (PIP3) in the membrane, where it is activated by PDK1 and mTORC2. Analysis of lipid levels in MK2/3-deficient bone marrow-derived macrophages (BMDMs) revealed a role for MK2/3 in regulating Akt activity by affecting availability of PIP3 at the membrane. These data describe a novel role for p38α-MK2/3 in regulating TLR-induced Akt activation in macrophages. PMID:23979601

  14. Rhein lysinate inhibits monocyte adhesion to human umbilical vein endothelial cells by blocking p38 signaling pathway.

    PubMed

    Lin, Yajun; Zhen, Yongzhan; Liu, Jiang; Wei, Jie; Tu, Ping; Hu, Gang

    2013-11-01

    The objective of this study was to investigate the effect of rhein lysinate (RHL) on monocyte adhesion and its mechanism. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the growth inhibition by drugs. The monocyte chemoattractant protein (MCP)-1 levels were assayed using MCP-1 ELISA. The expression of proteins was detected by Western blotting analysis. The results indicated that RHL inhibited monocyte adhesion in a dose- and time-dependent manner. RHL (<20 μmol/L) and lipopolysaccharide (LPS) had no effect on viability of human umbilical vein endothelial cells. Therefore, 20 μmol/L RHL was selected for this study. RHL inhibited secretion of MCP-1 induced by LPS and expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1. In the meantime, both RHL and p38 inhibitor (SB203580) inhibited phosphorylation of p38 and mitogen-activated protein kinase-activated protein kinase-2 (MAPKAPK-2) and transcription and expression of ICAM-1 and VCAM-1. In conclusion, RHL inhibits the transcription and expression of ICAM-1 and VCAM-1 by the p38/MAPKAPK-2 signaling pathway, and the effect of RHL on transcription and expression of ICAM-1 and VCAM-1 is similar to p38 inhibitor. RHL could be a prophylactic drug for atherosclerosis.

  15. 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.

  16. Dual role of the p38 MAPK/cPLA2 pathway in the regulation of platelet apoptosis induced by ABT-737 and strong platelet agonists

    PubMed Central

    Rukoyatkina, N; Mindukshev, I; Walter, U; Gambaryan, S

    2013-01-01

    p38 Mitogen-activated protein (MAP) kinase is involved in the apoptosis of nucleated cells. Although platelets are anucleated cells, apoptotic proteins have been shown to regulate platelet lifespan. However, the involvement of p38 MAP kinase in platelet apoptosis is not yet clearly defined. Therefore, we investigated the role of p38 MAP kinase in apoptosis induced by a mimetic of BH3-only proteins, ABT-737, and in apoptosis-like events induced by such strong platelet agonists as thrombin in combination with convulxin (Thr/Cvx), both of which result in p38 MAP kinase phosphorylation and activation. A p38 inhibitor (SB202190) inhibited the apoptotic events induced by ABT-737 but did not influence those induced by Thr/Cvx. The inhibitor also reduced the phosphorylation of cytosolic phospholipase A2 (cPLA2), an established p38 substrate, induced by ABT-737 or Thr/Cvx. ABT-737, but not Thr/Cvx, induced the caspase 3-dependent cleavage and inactivation of cPLA2. Thus, p38 MAPK promotes ABT-737-induced apoptosis by inhibiting the cPLA2/arachidonate pathway. We also show that arachidonic acid (AA) itself and in combination with Thr/Cvx or ABT-737 at low concentrations prevented apoptotic events, whereas at high concentrations it enhanced such events. Our data support the hypothesis that the p38 MAPK-triggered arachidonate pathway serves as a defense mechanism against apoptosis under physiological conditions. PMID:24263105

  17. Apigenin promotes osteogenic differentiation of human mesenchymal stem cells through JNK and p38 MAPK pathways.

    PubMed

    Zhang, Xue; Zhou, Chenhui; Zha, Xuan; Xu, Zhoumei; Li, Li; Liu, Yuyu; Xu, Liangliang; Cui, Liao; Xu, Daohua; Zhu, Baohua

    2015-09-01

    Apigenin is a plant-derived flavonoid and has been reported to prevent bone loss in ovariectomized mice, but the role of apigenin on osteogenic differentiation of human mesenchymal stem cells (hMSCs) has not been reported. In the present study, the effect of apigenin on osteogenic differentiation of hMSCs was explored. Our results showed that apigenin treatment significantly increased alkaline phosphatase (ALP) activity and mineralization in hMSCs. RT-PCR revealed that apigenin markedly up-regulated the mRNA expression of osteopontin (OPN) and the transcription factors runt-related transcription factor 2 (Runx2). The expression of Runx2 and osterix (OSX) proteins were also increased in hMSCs differentiating into osteoblasts after treatment with apigenin. Furthermore, we investigated the signaling pathways responsible for osteogenic differentiation of apigenin in hMSCs. We found that apigenin treatment significantly increased the levels of p-JNK, p-p38 in hMSCs and addition of the inhibitors of JNK (SP600125) or p38 MAPK (SB203580) eliminated the stimulating effects of apigenin. In addition, addition of SP600125 or SB203580 also blocked apigenin-induced ALP activity, OPN, Runx2, and OSX expression and meanwhile inhibited bone nodule formation. Taken together, these findings suggest apigenin promotes the osteogenesis of hMSCs through activation of JNK and p38 MAPK signal pathways which leads to Runx2 and OSX expressions to induce the formation of bone nodule.

  18. 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

  19. Involvement of AP-1 in p38MAPK signaling pathway in osteoblast apoptosis induced by high glucose.

    PubMed

    Feng, Z P; Deng, H C; Jiang, R; Du, J; Cheng, D Y

    2015-04-10

    We investigated the effect of p38MAPK/AP-1 (activator protein-1) signaling on the apoptosis of osteoblasts induced by high glucose. A lentivirus vector of small hairpin RNA (shRNA) targeting p38MAPK was constructed in vitro. Osteoblasts MC3T3-E1 cultured in vitro were treated with vehicle, high glucose, p38MAPK-shRNA transfection, p38MAPK inhibitor, and unrelated shRNA transfection. Apoptosis, protein levels of p38MAPK, and activities of AP-1 in MC3T3-E1 osteoblasts were measured using TUNEL and flow cytometry, Western blot analysis, and an electrophoretic mobility shift assay. Compared with the vehicle group, high glucose induced apoptosis of MC3T3-E1 osteoblasts and activated p38MAPK and AP-1. p38MAPK-shRNA transfection blocked the effect of high glucose stimulation, and the p38MAPK inhibitor showed similar effects as those observed in p38MAPK transfection. Unrelated shRNA had no effect on these changes in MC3T3-E1 osteoblasts induced by high glucose. Therefore, our results suggest that p38MAPK-shRNA reduce apoptosis of MC3T3-E1 osteoblasts induced by high glucose by inhibiting the p38MAPK-AP-1 signaling pathway.

  20. Histones-mediated lymphocyte apoptosis during sepsis is dependent on p38 phosphorylation and mitochondrial permeability transition.

    PubMed

    Liu, Zhan-Guo; Ni, Shu-Yuan; Chen, Gui-Ming; Cai, Jing; Guo, Zhen-Hui; Chang, Ping; Li, Yu-Sheng

    2013-01-01

    Lymphocyte apoptosis is one reason for immunoparalysis seen in sepsis, although the triggers are unknown. We hypothesized that molecules in plasma, which are up-regulated during sepsis, may be responsible for this. In this study, peripheral lymphocyte apoptosis caused by extracellular histones was confirmed both in mouse and human primary lymphocytes, in which histones induced lymphocyte apoptosis dose-dependently and time-dependently. To identify which intracellular signal pathways were activated, phosphorylation of various mitogen-activated protein kinases (MAPKs) were evaluated during this process, and p38 inhibitor (SB203580) was used to confirm the role of p38 in lymphocyte apoptosis induced by histones. To investigate the mitochondrial injury during these processes, we analyzed Bcl2 degradation and Rhodamine 123 to assess mitochondrial-membrane stability, via cyclosporin A as an inhibitor for mitochondrial permeability transition (MPT). Then, caspase 3 activation was also checked by western-blotting. We found that p38 phosphorylation, mitochondrial injury and caspase 3 activation occurred dose-dependently in histones-mediated lymphocyte apoptosis. We also observed that p38 inhibitor SB203580 decreased lymphocyte apoptotic ratio by 49% (P<0.05), and inhibition of MPT protected lymphocytes from apoptosis. Furthermore, to investigate whether histones are responsible for lymphocyte apoptosis, various concentrations of histone H4 neutralization antibodies were co-cultured with human primary lymphocytes and plasma from cecal ligation and puncture (CLP) mice or sham mice. The results showed that H4 neutralization antibody dose-dependently blocked lymphocyte apoptosis caused by septic plasma in vitro. These data demonstrate for the first time that extracellular histones, especially H4, play a vital role in lymphocyte apoptosis during sepsis which is dependent on p38 phosphorylation and mitochondrial permeability transition. Neutralizing H4 can inhibit lymphocyte

  1. 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

  2. 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.

  3. Low cell cholesterol levels increase NFkappaB activity through a p38 MAPK-dependent mechanism.

    PubMed

    Calleros, Laura; Lasa, Marina; Toro, María J; Chiloeches, Antonio

    2006-12-01

    Cholesterol, p38 MAPK and NFkappaB have been shown to participate in inflammation and cellular differentiation. Here, we examined the effect of cholesterol on NFkappaB-dependent transcription and the mechanisms underlying this effect in NIH3T3 cells. We show that chronic cholesterol depletion achieved with lipoprotein-deficient serum (LPDS) and 25-hydroxycholesterol (25-HC) treatment resulted in a significant increase in NFkappaB-dependent transcription, NFkappaB-DNA binding, IkappaBalpha degradation and p65/NFkappaB translocation to the nucleus, and the addition of exogenous cholesterol reversed these effects. Previously, we have shown that low cell cholesterol levels activate p38 MAPK. Here, we found that inhibition of p38 MAPK with the specific inhibitor SB203580 blocked the increase in NFkappaB activity, IkappaBalpha degradation and p65/NFkappaB translocation to the nucleus induced by cholesterol depletion. Moreover, the inhibition of the p38 MAPK downstream effector MSK1 with the specific inhibitor H89, or the overexpression of a kinase defective MSK1 abrogated the NFkappaB-dependent transcription induced by cholesterol depletion. On the other hand, the transactivation potential of p65/NFkappaB depends on phosphorylation of S276 by MSK1. We observed that cholesterol depletion increased the p65/NFkappaB transactivation capacity. This effect was reversed by cell cholesterol repletion or incubation with the SB203580 inhibitor. Moreover, the expression of a p65/NFkappaB S276A mutant was insensitive to cholesterol depletion. Together, our results demonstrate that cholesterol depletion induces NFkappaB transcriptional activity, not only by affecting the IkappaBalpha degradation and the translocation of p65/NFkappaB to the nucleus, but also regulating the p65/NFkappaB transactivating potential through a p38 MAPK/MSK1 mediated pathway.

  4. A2B adenosine receptors stimulate IL-6 production in primary murine microglia through p38 MAPK kinase pathway.

    PubMed

    Merighi, Stefania; Bencivenni, Serena; Vincenzi, Fabrizio; Varani, Katia; Borea, Pier Andrea; Gessi, Stefania

    2017-03-01

    The hallmark of neuroinflammation is the activation of microglia, the immunocompetent cells of the CNS, releasing a number of proinflammatory mediators implicated in the pathogenesis of neuronal diseases. Adenosine is an ubiquitous autacoid regulating several microglia functions through four receptor subtypes named A1, A2A, A2B and A3 (ARs), that represent good targets to suppress inflammation occurring in CNS. Here we investigated the potential role of ARs in the modulation of IL-6 secretion and cell proliferation in primary microglial cells. The A2BAR agonist 2-[[6-Amino-3,5-dicyano-4-[4-(cyclopropylmethoxy)phenyl]-2-pyridinyl]thio]-acetamide (BAY60-6583) stimulated IL-6 increase under normoxia and hypoxia, in a dose- and time-dependent way. In cells incubated with the blockers of phospholipase C (PLC), protein kinase C epsilon (PKC-ε) and PKC delta (PKC-δ) the IL-6 increase due to A2BAR activation was strongly reduced, whilst it was not affected by the inhibitor of adenylyl cyclase (AC). Investigation of cellular signalling involved in the A2BAR effect revealed that only the inhibitor of p38 mitogen activated protein kinase (MAPK) was able to block the agonist's effect on IL-6 secretion, whilst inhibitors of pERK1/2, JNK1/2 MAPKs and Akt were not. Stimulation of p38 by BAY60-6583 was A2BAR-dependent, through a pathway affecting PLC, PKC-ε and PKC-δ but not AC, in both normoxia and hypoxia. Finally, BAY60-6583 increased microglial cell proliferation involving A2BAR, PLC, PKC-ε, PKC-δ and p38 signalling. In conclusion, A2BARs activation increased IL-6 secretion and cell proliferation in murine primary microglial cells, through PLC, PKC-ε, PKC-δ and p38 pathways, thus suggesting their involvement in microglial activation and neuroinflammation.

  5. Caspase-independent apoptosis in infected macrophages triggered by sulforaphane via Nrf2/p38 signaling pathways

    PubMed Central

    Bonay, M; Roux, A-L; Floquet, J; Retory, Y; Herrmann, J-L; Lofaso, F; Deramaudt, TB

    2015-01-01

    Mycobacterium abscessus (Mabs), a non-tuberculous mycobacterium, is an emerging and rapidly growing opportunistic pathogen that is frequently found in patients with cystic fibrosis and in immunosuppressed patients. Its high tolerance to antibiotics is of great concern for public health. In this study, our results showed that human THP-1-derived macrophages infected with M. abscessus presented an increase in ROS production and cell necrosis. In addition, M. abscessus infection triggered activation of the Nuclear factor E2-related factor 2 (Nrf2) signaling pathway, and the induction of HO-1 and NQO1 expression levels. Interestingly, pretreatment of macrophages with sulforaphane (SFN), an activator of the antioxidant key regulator Nrf2, followed by M. abscessus infection significantly decreased mycobacterial burden. We demonstrated that this reduction in mycobacterial growth was due to an activation in cell apoptosis in SFN-pretreated and M. abscessus-infected macrophages. Pretreatment with specific MAPK inhibitors, PD98059, SP600125, and SB203580 to ERK, JNK, and p38 respectively, failed to inhibit induction of Nrf2 expression, suggesting that Nrf2 signaling pathway was upstream of MAPK signaling. Activation of cell apoptosis was caspase 3/7 independent but p38 MAPK dependent. Moreover, p38 MAPK induction was abolished in macrophages transfected with Nrf2 siRNA. In addition, p38 inhibitor abolished Nrf2-dependent apoptosis in infected macrophages. Taken together, our results indicate that modulation of the Nrf2 signaling using Nrf2 activators may help potentiate the actual drug therapies used to treat mycobacterial infection. PMID:27551455

  6. Inhibition of actin polymerization decreases osteogeneic differentiation of mesenchymal stem cells through p38 MAPK pathway

    PubMed Central

    2013-01-01

    Background Mesenchymal Stem Cells (MSC) are important candidates for therapeutic applications due to their ex vivo proliferation and differentiation capacity. MSC differentiation is controlled by both intrinsic and extrinsic factors and actin cytoskeleton plays a major role in the event. In the current study, we tried to understand the initial molecular mechanisms and pathways that regulate the differentiation of MSC into osteocytes or adipocytes. Results We observed that actin modification was important during differentiation and differentially regulated during adipogenesis and osteogenesis. Initial disruption of actin polymerization reduced further differentiation of MSC into osteocytes and osteogenic differentiation was accompanied by increase in ERK1/2 and p38 MAPK phosphorylation. However, only p38 MAPK phosphorylation was down regulated upon inhibition of actin polymerization which as accompanied by decreased CD49E expression. Conclusion Taken together, our results show that actin modification is a pre-requisite for MSC differentiation into osteocytes and adipocytes and osteogenic differentiation is regulated through p38 MAPK phosphorylation. Thus by modifying their cytoskeleton the differentiation potential of MSC could be controlled which might have important implications for tissue repair and regeneration. PMID:24070328

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

    PubMed

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

    2015-06-30

    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.

  8. Target gene specificity of USF-1 is directed via p38-mediated phosphorylation-dependent acetylation.

    PubMed

    Corre, Sébastien; Primot, Aline; Baron, Yorann; Le Seyec, Jacques; Goding, Colin; Galibert, Marie-Dominique

    2009-07-10

    How transcription factors interpret the output from signal transduction pathways to drive distinct programs of gene expression is a key issue that underpins development and disease. The ubiquitously expressed basic-helix-loop-helix leucine zipper upstream stimulating factor-1 binds E-box regulatory elements (CANNTG) to regulate a wide number of gene networks. In particular, USF-1 is a key component of the tanning process. Following UV irradiation, USF-1 is phosphorylated by the p38 stress-activated kinase on threonine 153 and directly up-regulates expression of the POMC, MC1R, TYR, TYRP-1 and DCT genes. However, how phosphorylation on Thr-153 might affect the activity of USF-1 is unclear. Here we show that, in response to DNA damage, oxidative stress and cellular infection USF-1 is acetylated in a phospho-Thr-153-dependent fashion. Phospho-acetylated USF-1 is nuclear and interacts with DNA but displays altered gene regulatory properties. Phospho-acetylated USF-1 is thus proposed to be associated with loss of transcriptional activation properties toward several target genes implicated in pigmentation process and cell cycle regulation. The identification of this critical stress-dependent USF-1 modification gives new insights into understanding USF-1 gene expression modulation associated with cancer development.

  9. A critical role for p38MAPK signalling pathway during reprogramming of human fibroblasts to iPSCs

    PubMed Central

    Neganova, Irina; Chichagova, Valeria; Armstrong, Lyle; Lako, Majlinda

    2017-01-01

    Reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) holds enormous promise for regenerative medicine. Reprogramming is a stepwise process with well-defined stages of initiation, maturation and stabilisation which are critically dependent on interactions between key pluripotency transcription factors, epigenetic regulators and signalling pathways. In this manuscript we have investigated the role of p38 MAPK signalling pathway and have shown a subpopulation- and phase-specific pattern of activation occurring during the initiation and maturation stage of reprogramming in partially and fully reprogrammed cells respectively. Downregulation of p38 MAPK activity via RNA interference or small molecule inhibitor led to cell accumulation in G1 phase of the cell cycle and reduced expression of cell cycle regulators during the initiation stage of reprogramming. This was associated with a significant downregulation of key pluripotency marker expression, disruption of mesenchymal to epithelial transition (MET), increased expression of differentiation markers and presence of partially reprogrammed cells which retained a typical gene expression profile of mesendodermal cells and were unable to progress to fully reprogrammed phenotype. Together our data indicate an important role for p38 MAPK activity in proliferation, MET progression and establishment of pluripotent phenotype, which are necessary steps for the development of human iPSCs. PMID:28155868

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

    PubMed Central

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

    2016-01-01

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

  11. Crosstalk between the p38 and TGF-β signaling pathways through TβRI, TβRII and Smad3 expression in plancental choriocarcinoma JEG-3 cells.

    PubMed

    Tan, Yusi; Xu, Qian; Li, Yuhong; Mao, Xiaodan; Zhang, Kongyan

    2014-09-01

    Choriocarcinoma is a highly aggressive tumor that develops from germ cells. Some choriocarcinomas originate in the testes or ovaries, while others may develop in the uterus after a normal pregnancy or after miscarriage. The tumor is characterized by early hematogenous spread to distal organs, such as the lung and brain. Transforming growth factor β1 (TGF-β1) is key in regulating tumor cell proliferation and invasion through a variety of Smad-dependent and -independent pathways, including the p38 mitogen-activated protein kinase (MAPK) pathway. There appears to be crosstalk between the TGF-β/Smad and p38 MAPK pathways; however, the molecular mechanisms underlying the crosstalk are not fully understood. The present study validated the role of TGF-β signaling in cancer progression and explored the interaction between Smad and p38 MAPK signaling on transduction mediators in choriocarcinoma using the JEG-3 cell line. MTT assay was used to detect the effect of TGF-β1 on JEG-3 cell proliferation. Cells were treated with p38 MAPK inhibitor and TGF-β receptor inhibitor, followed by TGF-β1, and reverse transcription quantitative real-time polymerase chain reaction was used to examine the transcriptional levels of Smad3 and TGF-β receptors. The data demonstrated that TGF-β can enhance the viability of JEG-3 cells. Blockade of the TGF-β and p38 MAPK pathways attenuated the expression of Smad3, TGF-β receptor type I (TβRI) and TβRII, and inhibited their expression in a dose-dependent manner. Analysis revealed that p38 MAPK is involved in and contributes to the TGF-β pathway, dependent on the regulation of TβRI, TβRII and Smad3. Further investigation of the interactions between the TGF-β and p38 MAPK pathways may offer potential venues for therapeutic intervention for choriocarcinoma.

  12. SIRT1 plays a neuroprotective role in traumatic brain injury in rats via inhibiting the p38 MAPK pathway

    PubMed Central

    Yang, Hong; Gu, Zheng-tao; Li, Li; Maegele, Mac; Zhou, Bi-ying; Li, Feng; Zhao, Ming; Zhao, Ke-sen

    2017-01-01

    Traumatic brain injury (TBI) is a major cause of disability and death in patients who experience a traumatic injury. Mitochondrial dysfunction is one of the main factors contributing to secondary injury in TBI-associated brain damage. Evidence of compromised mitochondrial function after TBI has been, but the molecular mechanisms underlying the pathogenesis of TBI are not well understood. Silent information regulator family protein 1 (SIRT1), a member of the NAD+-dependent protein deacetylases, has been shown to exhibit neuroprotective activities in animal models of various pathologies, including ischemic brain injury, subarachnoid hemorrhage and several neurodegenerative diseases. In this study, we investigated whether SIRT1 also exert neuroprotective effect post-TBI, and further explored the possible regulatory mechanisms involved in TBI pathogenesis. A lateral fluid-percussion (LFP) brain injury model was established in rats to mimic the insults of TBI. The expression levels of SIRT1, p-p38, cleaved caspase-9 and cleaved caspase-3 were all markedly increased and reached a maximum at 12 h post-TBI. In addition, mitochondrial function was impaired, evidenced by the presence of swollen and irregularly shaped mitochondria with disrupted and poorly defined cristae, a relative increase of the percentage of neurons with low ΔΨm, the opening of mPTP, and a decrease in neuronal ATP content, especially at 12 h post-TBI. Pretreatment with the SIRT1 inhibitor sirtinol (10 mg/kg, ip) induced p-p38 activation, exacerbated mitochondrial damage, and promoted the activation of the mitochondrial apoptosis pathway. In contrast, pretreatment with the p38 inhibitor SB203580 (200 μg/kg, ip) significantly attenuated post-TBI-induced expression of both cleaved caspase-9 and cleaved caspase-3 and mitochondrial damage, whereas it had no effects on SIRT1 expression. Together, these results reveal that the 12 h after TBI may be a crucial time at which secondary damage occurs; the

  13. Interferon-gamma expression by Th1 effector T cells mediated by the p38 MAP kinase signaling pathway.

    PubMed Central

    Rincón, M; Enslen, H; Raingeaud, J; Recht, M; Zapton, T; Su, M S; Penix, L A; Davis, R J; Flavell, R A

    1998-01-01

    Signal transduction via MAP kinase pathways plays a key role in a variety of cellular responses, including growth factor-induced proliferation, differentiation and cell death. In mammalian cells, p38 MAP kinase can be activated by multiple stimuli, such as pro-inflammatory cytokines and environmental stress. Although p38 MAP kinase is implicated in the control of inflammatory responses, the molecular mechanisms remain unclear. Upon activation, CD4+ T cells differentiate into Th2 cells, which potentiate the humoral immune response or pro-inflammatory Th1 cells. Here, we show that pyridinyl imidazole compounds (specific inhibitors of p38 MAP kinase) block the production of interferon-gamma (IFNgamma) by Th1 cells without affecting IL-4 production by Th2 cells. These drugs also inhibit transcription driven by the IFNgamma promoter. In transgenic mice, inhibition of the p38 MAP kinase pathway by the expression of dominant-negative p38 MAP kinase results in selective impairment of Th1 responses. In contrast, activation of the p38 MAP kinase pathway by the expression of constitutivelyactivated MAP kinase kinase 6 in transgenic mice caused increased production of IFNgamma during the differentiation and activation of Th1 cells. Together, these data demonstrate that the p38 MAP kinase is relevant for Th1 cells, not Th2 cells, and that inhibition of p38 MAP kinase represents a possible site of therapeutic intervention in diseases where a predominant Th1 immune response leads to a pathological outcome. Moreover, our study provides an additional mechanism by which the p38 MAP kinase pathway controls inflammatory responses. PMID:9582275

  14. Angiotensin II limits NO production by upregulating arginase through a p38 MAPK-ATF-2 pathway.

    PubMed

    Shatanawi, Alia; Lemtalsi, Tahira; Yao, Lin; Patel, Chintan; Caldwell, Ruth B; Caldwell, R William

    2015-01-05

    Enhanced vascular arginase activity can impair endothelium-dependent vasorelaxation by decreasing l-arginine availability to endothelial nitric oxide (NO) synthase, thereby reducing NO production and uncoupling NOS function. Elevated angiotensin II (Ang II) is a key component of endothelial dysfunction in many cardiovascular diseases and has been linked to elevated arginase activity. In this study we explored the signaling pathway leading to increased arginase expression/activity in response to Ang II in bovine aortic endothelial cells (BAEC). Our previous studies indicate involvement of p38 mitogen activated protein kinase (MAPK) in Ang II-induced arginase upregulation and reduced NO production. In this study, we further investigated the Ang II-transcriptional regulation of arginase 1 in endothelial cells. Our results indicate the involvement of ATF-2 transcription factor of the AP1 family in arginase 1 upregulation and in limiting NO production. Using small interfering RNA (siRNA) targeting ATF-2, we showed that this transcription factor is required for Ang II-induced arginase 1 gene upregulation and increased arginase 1 expression and activity, leading to reduced NO production. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay further confirmed the involvement of ATF-2. Moreover, our data indicate that p38 MAPK phosphorylates ATF-2 in response to Ang II. Collectively, our results indicate that Ang II increases endothelial arginase activity/expression through a p38 MAPK/ATF-2 pathway leading to reduced endothelial NO production. These signaling steps might be therapeutic targets for preventing vascular endothelial dysfunction associated with elevated arginase activity/expression.

  15. Suppression of Cartilage Degradation by Zingerone Involving the p38 and JNK MAPK Signaling Pathway.

    PubMed

    Ruangsuriya, Jetsada; Budprom, Piyaporn; Viriyakhasem, Nawarat; Kongdang, Patiwat; Chokchaitaweesuk, Chatchadawalai; Sirikaew, Nutnicha; Chomdej, Siriwadee; Nganvongpanit, Korakot; Ongchai, Siriwan

    2017-02-01

    Zingerone, an active compound that is present in cooked ginger, has been claimed to be a bioactive ingredient that holds the potential of preventing and/or treating diseases involving inflammation. In this study, zingerone was used to discover its properties against joint inflammation using interleukin-1β-induced osteoarthritis in cartilage explant and cell culture models. Zingerone was supplemented into the cartilage explant and cell culture media at different concentrations along with the presence of interleukin-1β, an inducer of osteoarthritis. Markers indicating cartilage degradation, inflammation, and the signaling molecules involved in the inflammatory induction were investigated. Diacerien, an anti-osteoarthritic drug, was used as a positive control. Zingerone at a concentration of 40 µM reduced the level of matrix metalloproteinase-13 to about 31.95 ± 4.33 % compared with the interleukin-1β-treated group and halted cartilage explant degradation as indicated by reducing the accumulative release of sulfated glycosaminoglycans by falling to the control concomitantly with an elevation of the remaining contents of uronic acid and collagen in the explant tissues when zingerone was added. In the SW1353 cell line model, zingerone efficiently suppressed the expression of TNF-α, interleukin-6, and interleukin-8 mRNA levels and tended to reduce the levels of both p38 and c-Jun N-terminal kinase phosphorylation. From the results of this study, it can be concluded that zingerone potentially reduced cartilage degradation, which is partially involved in p38 and c-Jun N-terminal kinases of the mitogen activator protein kinase signaling pathway leading to the reduction of proinflammatory cytokine amplification effects and cartilage-degrading enzyme syntheses. This finding supports the contention that ginger holds positive pharmaceutical effects against osteoarthritis.

  16. 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

  17. 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

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

    PubMed Central

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

    2015-01-01

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

  19. 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.

  20. 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

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

    PubMed

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

    2015-05-01

    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.

  2. 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

  3. Targeting P38 Pathway Regulates Bony Formation via MSC Recruitment during Mandibular Distraction Osteogenesis in Rats

    PubMed Central

    Yang, Zi-hui; Wu, Bao-lei; Ye, Chen; Jia, Sen; Yang, Xin-jie; Hou, Rui; Lei, De-lin; Wang, Lei

    2016-01-01

    Distraction osteogenesis (DO) is a widely used self-tissue engineering. However, complications and discomfort due to the long treatment period are still the bottleneck of DO. Novel strategies to accelerate bone formation in DO are still needed. P38 is capable of regulating the osteogenic differentiation of both mesenchymal stem cells (MSCs) and osteoblasts, which are crucial to bone regeneration. However, it is not clear whether targeting p38 could regulate bony formation in DO. The purpose of the current work was to investigate the effects of local application of either p38 agonist anisomycin or p38 inhibitor SB203580 in a rat model of DO. 30 adult rats were randomly divided into 3 groups: (A) rats injected with DMSO served as the control group; (B) rats injected with p38 agonist anisomycin; (C) rats injected with p38 inhibitor SB203580. All the rats were subjected to mandibular distraction and the injection was performed daily during this period. The distracted mandibles were harvested on days 15 and 30 after surgery and subjected to the following analysis. Micro-computed tomography and histological evaluation results showed that local application of p38 agonist anisomycin increased new bone formation in DO, whereas p38 inhibitor SB203580 decreased it. Immunohistochemical analysis suggested that anisomycin promoted MSC recruitment in the distraction gap. In conclusion, this study demonstrated that local application of p38 agonist anisomycin can increase new bone formation during DO. This study may lead to a novel cell-based strategy for the improvement of bone regeneration. PMID:27766028

  4. Bone Morphogenetic Protein-9 Induces PDLSCs Osteogenic Differentiation through the ERK and p38 Signal Pathways

    PubMed Central

    Ye, Guo; Li, Conghua; Xiang, Xuerong; Chen, Chu; Zhang, Ruyi; Yang, Xia; Yu, Xuesong; Wang, Jinhua; Wang, Lan; Shi, Qiong; Weng, Yaguang

    2014-01-01

    Periodontal ligament stem cells (PDLSCs) with bone morphogenic ability are used to treat diseases such as periodontitis. Their treatment potential is increased when used in combination with proteins that induce osteogenic differentiation. For example, bone morphogenetic protein-9 (BMP9) has been found to have potent osteogenic activity. In the present study, PDLSCs were isolated from human periodontal membrane and infected with recombinant adenoviruses expressing BMP9 (Ad-BMP9). Levels of osteogenic markers such as runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCN) as well as mineralization ability were measured. The results showed that BMP9 promoted bone formation of PDLSCs. In other experiments, SB203580 and PD98059, which are inhibitors of p38 and ERK1/2, respectively, were used to determine if these kinases are involved in the osteogenic differentiation process. The resulting protein expression profiles and osteogenic markers of PDLSCs revealed that the mitogen-activated protein kinase (MAPK) signaling pathway might play an important role in the process of BMP9-induced osteogenic differentiation of PDLSCs. PMID:25136261

  5. 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.

  6. Activation of multiple MAPK pathways (ERKs, JNKs, p38-MAPK) by diverse stimuli in the amphibian heart.

    PubMed

    Aggeli, I K; Gaitanaki, C; Lazou, A; Beis, I

    2001-05-01

    We investigated the expression and activation of three MAPK subfamilies in the isolated perfused amphibian heart. ERK was detected as a 43 kDa band; p38-MAPK was detected as a band corresponding to 38 kDa and JNKs were detected as two bands corresponding to 46 and 52 kDa, respectively. PMA induced the activation of the ERK pathway as assessed by determining the phosphorylation state of ERK and the upstream component MEK1/2. PD98059 abolished this activation. p38-MAPK was phosphorylated by sorbitol (almost 12-fold, maximal within 10-15 min) and JNKs were phosphorylated and activated by sorbitol or anoxia/reoxygenation (approximately 4- and 2.5-fold, respectively). SB203580 completely blocked the activation of p38-MAPK by sorbitol. These results indicate that the MAPK pathways activated by phorbol esters, hyperosmotic stress or anoxia/ reoxygenation in the amphibian heart may have an important role in this experimental system.

  7. 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.

  8. Trichosanatine alleviates oxidized low-density lipoprotein induced endothelial cells injury via inhibiting the LOX-1/p38 MAPK pathway.

    PubMed

    Zhang, Lei; Jia, Yu-Hua; Zhao, Xiao-Shan; Zhou, Feng-Hua; Pan, Yun-Yun; Wan, Qiang; Cui, Xiao-Bing; Sun, Xue-Gang; Chen, Yu-Yao; Zhang, Yu; Cheng, Sai-Bo

    2016-01-01

    The LOX-1/p38 mitogen-activated protein kinase (MAPK) pathway has been proved to participate in the endothelial dysfunction in atherosclerosis. Trichosanatineis is an active compound isolated from the peel of Trichosanthes kirilowii. This study aims to determine whether trichosanatine prevents the oxidized low-density lipoprotein (ox-LDL)-induced insult through inhibition of the LOX-1/p38 MAPK pathway in HUVECs. HUVECs were treated with 150 mg/ml ox-LDL for 24 h to establish an ox-LDL-induced endothelial injury model. Cell viability, mitochondrial membrane potential (MMP), apoptosis, reactive oxygen species (ROS) level, LOX-1 and p38 MAPK expression level were measured. The results indicated that HUVECs were pretreated with either 100 mM trichosanatine or LOX-1 shRNA prior to exposure to ox-LDL for 24 h. Exposure of HUVECs to 150 mg/ml ox-LDL for 24 h significantly up-regulated the expression levels of LOX-1. The increased expression levels of LOX-1 were markedly attenuated by pretreatment with 100 mM trichosanatine. In addition, the ox-LDL-induced increase in phosphorylated (p) p38 MAPK expression was ameliorated by pretreatment with LOX-1 shRNA. Pretreatment of HUVECs with either trichosanatine or LOX-1 shRNA before exposure to ox-LDL significantly inhibited the ox-LDL-induced injuries, as evidenced by an increase in cell viability, a decrease in apoptotic cells, a ROS generation and a loss of MMP. In conclusion, we have demonstrated for the first time that the LOX-1/p38 MAPK pathway contributes to the ox-LDL-induced injury in HUVECs. Meanwhile, the trichosanatine protects the HUVECs against ox-LDL-induced injury at least in part by inhibiting the activated of LOX-1/p38 MAPK pathway.

  9. Trichosanatine alleviates oxidized low-density lipoprotein induced endothelial cells injury via inhibiting the LOX-1/p38 MAPK pathway

    PubMed Central

    Zhang, Lei; Jia, Yu-Hua; Zhao, Xiao-Shan; Zhou, Feng-Hua; Pan, Yun-Yun; Wan, Qiang; Cui, Xiao-Bing; Sun, Xue-Gang; Chen, Yu-Yao; Zhang, Yu; Cheng, Sai-Bo

    2016-01-01

    The LOX-1/p38 mitogen-activated protein kinase (MAPK) pathway has been proved to participate in the endothelial dysfunction in atherosclerosis. Trichosanatineis is an active compound isolated from the peel of Trichosanthes kirilowii. This study aims to determine whether trichosanatine prevents the oxidized low-density lipoprotein (ox-LDL)-induced insult through inhibition of the LOX-1/p38 MAPK pathway in HUVECs. HUVECs were treated with 150 mg/ml ox-LDL for 24 h to establish an ox-LDL-induced endothelial injury model. Cell viability, mitochondrial membrane potential (MMP), apoptosis, reactive oxygen species (ROS) level, LOX-1 and p38 MAPK expression level were measured. The results indicated that HUVECs were pretreated with either 100 mM trichosanatine or LOX-1 shRNA prior to exposure to ox-LDL for 24 h. Exposure of HUVECs to 150 mg/ml ox-LDL for 24 h significantly up-regulated the expression levels of LOX-1. The increased expression levels of LOX-1 were markedly attenuated by pretreatment with 100 mM trichosanatine. In addition, the ox-LDL-induced increase in phosphorylated (p) p38 MAPK expression was ameliorated by pretreatment with LOX-1 shRNA. Pretreatment of HUVECs with either trichosanatine or LOX-1 shRNA before exposure to ox-LDL significantly inhibited the ox-LDL-induced injuries, as evidenced by an increase in cell viability, a decrease in apoptotic cells, a ROS generation and a loss of MMP. In conclusion, we have demonstrated for the first time that the LOX-1/p38 MAPK pathway contributes to the ox-LDL-induced injury in HUVECs. Meanwhile, the trichosanatine protects the HUVECs against ox-LDL-induced injury at least in part by inhibiting the activated of LOX-1/p38 MAPK pathway. PMID:28078016

  10. Quercetin regulates the sestrin 2-AMPK-p38 MAPK signaling pathway and induces apoptosis by increasing the generation of intracellular ROS in a p53-independent manner.

    PubMed

    Kim, Guen Tae; Lee, Se Hee; Kim, Jong Il; Kim, Young Min

    2014-04-01

    The induction of apoptosis in cancer cells is a therapeutic strategy for the treatment of cancer. In the present study, we investigated the regulatory mechanisms responsible for quercetin-induced apoptosis, mamely the increased expression of sestrin 2 and the activation of the 5' AMP-activated protein kinase (AMPK)/p38 MAPK signaling pathway. Our results revealed that quercetin induced apoptosis by generating the production of intracellular reactive oxygen species (ROS) and increasing the expression of sestrin 2. The induction of apoptosis by quercetin occurred through the activation of the AMPK/p38 signaling pathway and was dependent on sestrin 2. However, the silencing of sestrin 2 using small interfering RNA (siRNA) targeting sestrin 2 revealed that quercetin did not regulate AMPK or p38 phosphorylation in the cells in which sestrin 2 was silenced. On the other hand, it has been previously reported that sestrin 2 expression is not dependent on p53 expression under hypoxic conditions, whereas DNA damage is dependent on p53. We demonstrate that the increase in the expression of sestrin 2 by quercetin-generated intracellular ROS is p53-independent. The increased expression of sestrin 2 induced apoptosis through the AMPK/p38 signaling pathway in the HT-29 colon cancer cells, which are p53 mutant, treated with quercetin. Thus, our data suggest that quercetin induces apoptosis by reducing mitochondrial membrane potential, generating intracellular ROS production and increasing sestrin 2 expression through the AMPK/p38 pathway. In addition, p53 is not a necessary element for an apoptotic event induced by sestrin 2.

  11. Pigment epithelium-derived factor and its phosphomimetic mutant induce JNK-dependent apoptosis and p38-mediated migration arrest.

    PubMed

    Konson, Alexander; Pradeep, Sunila; D'Acunto, Cosimo Walter; Seger, Rony

    2011-02-04

    Pigment epithelium-derived factor (PEDF) is a potent endogenous inhibitor of angiogenesis and a promising anticancer agent. We have previously shown that PEDF can be phosphorylated and that distinct phosphorylations differentially regulate its physiological functions. We also demonstrated that triple phosphomimetic mutant (EEE-PEDF), has significantly increased antiangiogenic activity and is much more efficient than WT-PEDF in inhibiting neovascularization and tumor growth. The enhanced antiangiogenic effect was associated with a direct ability to facilitate apoptosis of tumor-residing endothelial cells (ECs), and subsequently, disruption of intratumoral vascularization. In the present report, we elucidated the molecular mechanism by which EEE-PEDF exerts more profound effects at the cellular level. We found that EEE-PEDF suppresses EC proliferation due to caspase-3-dependent apoptosis and also inhibits migration of the EC much better than WT-PEDF. Although WT-PEDF and EEE-PEDF did not affect proliferation and did not induce apoptosis of cancer cells, these agents efficiently inhibited cancer cell motility, with EEE-PEDF showing a stronger effect. The stronger activity of EEE-PEDF was correlated with a better binding to laminin receptors. Furthermore, the proapoptotic and antimigratory activities of WT-PEDF and EEE-PEDF were found regulated by differential activation of two distinct MAPK pathways, namely JNK and p38, respectively. We show that JNK and p38 phosphorylation is much higher in cells treated with EEE-PEDF. JNK leads to apoptosis of ECs, whereas p38 leads to anti-migratory effect in both EC and cancer cells. These results reveal the molecular signaling mechanism by which the phosphorylated PEDF exerts its stronger antiangiogenic, antitumor activities.

  12. Protein-arginine Methyltransferase 1 Suppresses Megakaryocytic Differentiation via Modulation of the p38 MAPK Pathway in K562 Cells*

    PubMed Central

    Chang, Yuan-I; Hua, Wei-Kai; Yao, Chao-Ling; Hwang, Shiaw-Min; Hung, Yi-Chi; Kuan, Chih-Jen; Leou, Jiun-Shyang; Lin, Wey-Jinq

    2010-01-01

    Protein-arginine methyltransferase 1 (PRMT1) plays pivotal roles in various cellular processes. However, its role in megakaryocytic differentiation has yet to be investigated. Human leukemia K562 cells have been used as a model to study hematopoietic differentiation. In this study, we report that ectopic expression of HA-PRMT1 in K562 cells suppressed phorbol 12-myristate 13-acetate (PMA)-induced megakaryocytic differentiation as demonstrated by changes in cytological characteristics, adhesive properties, and CD41 expression, whereas knockdown of PRMT1 by small interference RNA promoted differentiation. Impairment of the methyltransferase activity of PRMT1 diminished the suppressive effect. These results provide evidence for a novel role of PRMT1 in negative regulation of megakaryocytic differentiation. Activation of ERK MAPK has been shown to be essential for megakaryocytic differentiation, although the role of p38 MAPK is still poorly understood. We show that knockdown of p38α MAPK or treatment with the p38 inhibitor SB203580 significantly enhanced PMA-induced megakaryocytic differentiation. Further investigation revealed that PRMT1 promotes activation of p38 MAPK without inhibiting activation of ERK MAPK. In p38α knockdown cells, PRMT1 could no longer suppress differentiation. In contrast, enforced expression of p38α MAPK suppressed PMA-induced megakaryocytic differentiation of parental K562 as well as PRMT1-knockdown cells. We propose modulation of the p38 MAPK pathway by PRMT1 as a novel mechanism regulating megakaryocytic differentiation. This study thus provides a new perspective on the promotion of megakaryopoiesis. PMID:20442406

  13. p38α MAPK regulates proliferation and differentiation of osteoclast progenitors and bone remodeling in an aging-dependent manner

    PubMed Central

    Cong, Qian; Jia, Hao; Li, Ping; Qiu, Shoutao; Yeh, James; Wang, Yibin; Zhang, Zhen-Lin; Ao, Junping; Li, Baojie; Liu, Huijuan

    2017-01-01

    Bone mass is determined by the balance between bone formation, carried out by mesenchymal stem cell-derived osteoblasts, and bone resorption, carried out by monocyte-derived osteoclasts. Here we investigated the potential roles of p38 MAPKs, which are activated by growth factors and cytokines including RANKL and BMPs, in osteoclastogenesis and bone resorption by ablating p38α MAPK in LysM+monocytes. p38α deficiency promoted monocyte proliferation but regulated monocyte osteoclastic differentiation in a cell-density dependent manner, with proliferating p38α−/− cultures showing increased differentiation. While young mutant mice showed minor increase in bone mass, 6-month-old mutant mice developed osteoporosis, associated with an increase in osteoclastogenesis and bone resorption and an increase in the pool of monocytes. Moreover, monocyte-specific p38α ablation resulted in a decrease in bone formation and the number of bone marrow mesenchymal stem/stromal cells, likely due to decreased expression of PDGF-AA and BMP2. The expression of PDGF-AA and BMP2 was positively regulated by the p38 MAPK-Creb axis in osteoclasts, with the promoters of PDGF-AA and BMP2 having Creb binding sites. These findings uncovered the molecular mechanisms by which p38α MAPK regulates osteoclastogenesis and coordinates osteoclastogenesis and osteoblastogenesis. PMID:28382965

  14. The Natural Pesticide Dihydrorotenone Induces Human Plasma Cell Apoptosis by Triggering Endoplasmic Reticulum Stress and Activating p38 Signaling Pathway

    PubMed Central

    Cao, Biyin; Zhang, Zubin; Li, Jie; Schimmer, Aaron D.; He, Sudan; Mao, Xinliang

    2013-01-01

    Dihydrorotenone (DHR) is a natural pesticide widely used in farming industry, such as organic produces. DHR is a potent mitochondrial inhibitor and probably induces Parkinsonian syndrome, however, it is not known whether DHR is toxic to other systems. In the present study, we evaluated the cytotoxicity of DHR on human plasma cells. As predicted, DHR impaired mitochondrial function by decreasing mitochondrial membrane potential in plasma cells. Because mito-dysfunction leads to unfolded protein response (UPR) and endoplasmic reticulum (ER) stress, we examined the signature proteins in ER stress, including GRP78, ATF4, and CHOP. After DHR treatment, these proteins were significantly upregulated. It is reported that activation of the mitogen-activated protein kinases p38 and JNK are involved in endoplasmic reticulum stress. However, in the subsequent study, DHR was found to activate p38 but not the JNK signaling. When pre-treated with p38 inhibitor SB203580, activation of p38 and cell apoptosis induced by DHR was partially blocked. Thus, we found that DHR induced human plasma cell death by activating the p38 but not the JNK signaling pathway. Because plasma cells are very important in the immune system, this study provided a new insight in the safety evaluation of DHR application. PMID:23922854

  15. Exposure to p,p'-DDE Induces Morphological Changes and Activation of the PKCα-p38-C/EBPβ Pathway in Human Promyelocytic HL-60 Cells.

    PubMed

    Torres-Avilés, Nallely A; Albores-García, Damaris; Luna, Ana L; Moreno-Galván, Monica; Salgado-Bustamante, Mariana; Portales-Pérez, Diana Patricia; Calderón-Aranda, Emma S

    2016-01-01

    Dichlorodiphenyldichloroethylene (p,p'-DDE), the most persistent metabolite of dichlorodiphenyltrichloroethane (DDT), is still present in the human population. Both are present in the bone marrow of patients with bone marrow disorders, but thus far there are no studies that assess the capability of p,p'-DDE to affect myeloid cells. The aim of this study was to determine the effect of p,p'-DDE on promyelocytic cell differentiation and intracellular pathways related to this event. p,p'-DDE induced morphological changes compatible with promyelocytic differentiation in a concentration-dependent manner. The p,p'-DDE effect on [Ca(2+)]i, C/EBPβ protein levels, PKCα and p38 activation, and the role of oxidative stress or PLA2 was assayed. Exposure to 1.9 μg/mL of p,p'-DDE increased [Ca(2+)]i, PKCα, p38, and C/EBPβ protein levels; the increase of nuclear C/EBPβ protein was dependent on p38. PKCα phosphorylation was dependent on PLA2 and p,p'-DDE-induced oxidative stress. p38 phosphorylation induced by p,p'-DDE was dependent on PLA2, PKC activation, and oxidative stress. These effects of p,p'-DDE at concentrations found in human bone marrow may induce alterations in immature myeloid cells and could affect their cellular homeostasis. In order to establish the risk from exposure to p,p'-DDE on the development of bone marrow disorders in humans, these effects deserve further study.

  16. Cu2+ and acute thermal stress induce protective events via the p38-MAPK signalling pathway in the perfused Rana ridibunda heart.

    PubMed

    Gaitanaki, Catherine; Pliatska, Maria; Stathopoulou, Konstantina; Beis, Isidoros

    2007-02-01

    In the present study, we investigated the induction of the p38-MAPK signalling pathway by copper, as exemplified by CuCl(2), in the isolated perfused heart of the amphibian Rana ridibunda. We found that p38-MAPK phosphorylation by CuCl(2) occurs in a dose-dependent manner, with maximum activation (8.73+/-1.43-fold relative to control values) attained by perfusion with 500 micromol l(-1) CuCl(2) for 15 min, while this activation sustained even after 60 min of reperfusion with normal bicarbonate buffer. CuCl(2) also induced the phosphorylation of the small heat shock protein 27 (Hsp27) in a p38-MAPK dependent manner, as revealed by experiments using the p38-MAPK inhibitor SB203580. p38-MAPK and Hsp27 phosphorylations were also strongly induced by hyperthermia (42 degrees C), while the simultaneous use of hyperthermia and CuCl(2) had a synergistic effect on p38-MAPK activation. Furthermore, perfusions with the potent antioxidant L-ascorbic acid (100 micromol l(-1)), the antioxidant enzymes catalase (CAT) (150 U ml(-1)) or superoxide dismutase (SOD) (30 U ml(-1)) in the presence of 500 micromol l(-1) CuCl(2) did not attenuate the CuCl(2)-induced p38-MAPK activation, implying that at least the reactive oxygen species (ROS) scavenged by these agents are not implicated in this kinase activation. The p38-MAPK phosphorylation induced by the combined action of CuCl(2) and hyperthermia was partially inhibited by catalase, indicating that hyperthermia possibly activates the kinase through the production of H(2)O(2). Caspase-3, an effector protease of apoptosis, remained inactive in hearts perfused at normal or hyperthermic conditions, in the absence or presence of 500 micromol l(-1) CuCl(2). All the above results suggest that, in the amphibian Rana ridibunda heart, p38-MAPK activation by copper has a possible protective role through the small Hsp27.

  17. Endothelin-1 protects human melanocytes from UV-induced DNA damage by activating JNK and p38 signalling pathways.

    PubMed

    von Koschembahr, Anne M; Swope, Viki B; Starner, Renny J; Abdel-Malek, Zalfa A

    2015-04-01

    Endothelin-1 is a paracrine factor with mitogenic, melanogenic and survival effects on cultured human melanocytes. We report that endothelin-1 signalling reduced the generation and enhanced the repair of ultraviolet radiation (UV)-induced DNA photoproducts, and inhibited apoptosis of human melanocytes, without increasing cAMP levels, melanin content or proliferation. Treatment with endothelin-1 activated the MAP kinases JNK and p38, as evidenced by phosphorylation of their target, activating transcription factor-2 (ATF-2). Endothelin-1 also enhanced the phosphorylation of JNK, p38 and ATF-2 by UV. The effects of endothelin-1 were dependent on increasing intracellular calcium mobilization by endothelin B receptor signalling. Activation of both JNK and p38 was required for reducing DNA photoproducts, but only JNK partially contributed to the survival effect of endothelin-1. ATF-2 activation depended mainly on JNK, yet was not sufficient for the effect of endothelin-1 on UV-induced DNA damage, suggesting the requirement for other JNK and p38 targets for this effect. Our results underscore the significance of endothelin-1 and endothelin B receptor signalling in reducing the genotoxic effects of UV via activating JNK and p38, hence restoring genomic stability of melanocytes.

  18. TGF-β regulates phosphorylation and stabilization of Sox9 protein in chondrocytes through p38 and Smad dependent mechanisms

    PubMed Central

    Coricor, George; Serra, Rosa

    2016-01-01

    Members of the TGF-β superfamily are important regulators of chondrocyte function. Sox9, a key transcriptional regulator of chondrogenesis, is required for TGF-β-mediated regulation of specific cartilage genes. TGF-β can signal through a canonical, Smad-mediated pathway or non-conical pathways, including p38. Here we show that both pathways are activated in chondrocytes after treatment with TGF-β and that TGF-β stabilizes Sox9 protein and increases phosphorylation of Sox9. Mutagenesis of potential serine phosphorylation sites on Sox9 was used to demonstrate that serine 211 is required to maintain normal basal levels of Sox9 as well as mediate increased Sox9 levels in response to TGF-β. The serine 211 site is in a motif that is targeted by p38 kinase. We used siRNA and pharmacological agents to show that p38 and Smad3 independently regulate the phosphorylation and stability of Sox9. Previously, we demonstrated that Papss2 is a downstream transcriptional target of Sox9 and TGF-β. Here we show that p38 is required for TGF-β-mediated regulation of Papss2 mRNA. Together the results suggest a new mechanism for TGF-β-mediated gene regulation in chondrocytes via p38 and phosphorylation and stabilization of Sox9. Understanding how TGF-β regulates Sox9 may lead to identification of therapeutic targets for OA. PMID:27929080

  19. Portulacerebroside A inhibits adhesion, migration, and invasion of human leukemia HL60 cells and U937 cells through the regulation of p38/JNK signaling pathway

    PubMed Central

    Ye, Qidong; Liao, Xuelian; Fu, Pan; Dou, Jiaying; Chen, Kai; Jiang, Hui

    2016-01-01

    Acute myeloid leukemia (AML) is a highly malignant hematopoietic tumor. This study aimed to explore the effect of portulacerebroside A (PCA) on the adhesion, migration, and invasion in human leukemia HL60 cells and U937 cells and clarify the possible mechanisms involved, which could provide potential strategies for the treatment of AML. By methyl thiazolyl tetrazolium analysis, it was found that PCA (1–10 μM) suppressed the cell viability in a time- and dose-dependent manner. A total of 1, 2, and 5 μM of PCA dramatically inhibited the adhesion, migration, and invasion of HL60 cells and U937 cells in a dose-dependent manner. Phosphorylation level of JNK and P38 protein level was measured by Western blot. After the real-time quantification polymerase chain reaction and Western blot detection of the total RNA and protein, messenger RNA, and protein expression levels of Ras homologous C (RhoC), metastasis-associated gene 1 (MTA1) and matrix metalloproteinase-2/9 (MMP-2/9) were decreased significantly in a dose-dependent manner. The phosphorylation level of c-Jun N-terminal kinase (JNK) and P38 mitogen-activated protein kinase (P38) was decreased dramatically in HL60 cells and U937 cells after PCA treatment. In conclusion, PCA significantly inhibits the adhesion, migration, and invasion of HL60 cells and U937 cells by suppressing the p38/JNK pathway and regulating the expressions of related genes. PMID:27956839

  20. Suppression of Nestin reveals a critical role for p38-EGFR pathway in neural progenitor cell proliferation

    PubMed Central

    Hu, Wentao; Lu, Hong; Wang, Shang; Yin, Wenhan; Liu, Xujie; Dong, Lin; Chiu, Richard; Shen, Li; Lu, Wen-Jing; Lan, Feng

    2016-01-01

    The expression of intermediate filament Nestin is necessary for the neural progenitor cells (NPCs) to maintain stemness, but the underlying cellular and molecular mechanism remains unclear. In this study, we demonstrated that Nestin is required for the self-renew of NPCs through activating MAPK and EGFR pathways. Knockdown of Nestin by shRNA inhibited cell cycle progression and proliferation in mouse NPCs. Moreover, suppression of Nestin reduced expression of the epidermal growth factor receptor (EGFR) in NPCs and inhibited the mitogenic effects of EGF on these cells. Treatment of NPCs with p38-MAPK inhibitor PD169316 reversed cell cycle arrest caused by the knockdown of Nestin. Our findings indicate that Nestin promotes NPC proliferation via p38-MAPK and EGFR pathways, and reveals the necessity of these pathways in NPCs self-renewal. PMID:27894083

  1. Monosodium urate crystal-induced pro-interleukin-1β production is post-transcriptionally regulated via the p38 signaling pathway in human monocytes

    PubMed Central

    Chung, Yeon-Ho; Kim, Dong-Hyun; Lee, Won-Woo

    2016-01-01

    IL-1β is a key mediator of sterile inflammation in response to endogenous particulates, a type of damage-associated molecular pattern (DAMPs) molecule derived from damaged cells. Despite the well-known role of sterile particulates such as monosodium urate (MSU) crystals as inflammasome inducers in monocytes/macrophages, little is known regarding how pro-IL-1β synthesis is induced under sterile inflammatory conditions. We provide evidence that MSU crystals post-transcriptionally induce the rapid production of pro-IL-1β in human primary monocytes. Metabolic labeling and pull-down assays for newly-synthesized proteins clearly showed that MSU crystals rapidly, within 30 min, induce the synthesis of pro-IL-1β as well as global proteins. Notably, MSU crystal-induced pro-IL-1β synthesis is selectively dependent on the p38 MAPK pathway, whereas global protein synthesis is mediated via the mTOR, ERK1/2, and p38 pathways. Furthermore, inhibition of Mnk1, a substrate of p38, blocked MSU crystal-induced pro-IL-1β synthesis downstream of eIF4E phosphorylation. In addition, the p38 MAPK pathway leading to phosphorylation of MK2 was also critical for stabilization of pro-IL-1β mRNA following MSU stimulation. Our findings demonstrate that post-transcriptional regulation via p38 MAPK plays a central role in the rapid synthesis of pro-IL-1β in response to MSU crystals, which is an essential step for IL-1β production in human monocytes. PMID:27694988

  2. MDA-7/IL-24 inhibits Nrf2-mediated antioxidant response through activation of p38 pathway and inhibition of ERK pathway involved in cancer cell apoptosis.

    PubMed

    Tian, H; Zhang, D; Gao, Z; Li, H; Zhang, B; Zhang, Q; Li, L; Cheng, Q; Pei, D; Zheng, J

    2014-10-01

    Reactive oxygen species (ROS) have a crucial role in melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24)-induced cancer cell apoptosis. However, cancer cell has a series of protective mechanisms to resist ROS damage. Nuclear factor erythroid 2-related factor 2 (Nrf2) activates antioxidant response element (ARE)-mediated gene expression involved in cellular protection against oxidative stress. As the Nrf2 repressor, Kelch-like ECH-associated protein-1 (Keap1) sequesters Nrf2 in cytoplasm to block Nrf2 nuclear translocation. In the present study, administration of MDA-7/IL-24 by means of tumor-selective replicating adenovirus (ZD55-IL-24) was used to investigate whether ZD55-IL-24 could attenuate Nrf2-mediated oxidative stress response in cancer cell. We found that ZD55-IL-24 effectively strengthened the association between Nrf2 and Keap1 to restrict Nrf2 nuclear translocation, thereby inhibiting ARE-dependent transcriptional response. To evaluate the detailed mechanism underlying the suppression of ZD55-IL-24 on Nrf2-mediated oxidative stress response, we further tested three different mitogen-activated protein kinase (MAPK) signaling pathways in A549 and HeLa cells transfected by ZD55-IL-24. Our data showed that ZD55-IL-24 inhibited extracellular signal-regulated kinase (ERK) signal pathway but activated p38 and c-Jun-NH2-kinase (JNK) signal pathways to exert the tumor-specific apoptosis. Moreover, ERK pathway inhibitor U0126 prevented Nrf2 phosphorylation at Ser40 to retard Nrf2 nuclear translocation, thus decreasing antioxidant gene transcription. In contrast, p38 pathway inhibitor SB203580 obviously promoted the dissociation of Nrf2 from Keap1 to promote antioxidant gene transcription. However, JNK pathway had no effect on Nrf2 subcellular localization or the association of Nrf2 with Keap1. Conclusively, our results indicate that ZD55-IL-24 inhibits Nrf2-mediated oxidative stress response not only by activating p38 signal pathway to

  3. Physalin A induces G2/M phase cell cycle arrest in human non-small cell lung cancer cells: involvement of the p38 MAPK/ROS pathway.

    PubMed

    Kang, Ning; Jian, Jun-Feng; Cao, Shi-Jie; Zhang, Qiang; Mao, Yi-Wei; Huang, Yi-Yuan; Peng, Yan-Fei; Qiu, Feng; Gao, Xiu-Mei

    2016-04-01

    Physalin A (PA) is an active withanolide isolated from Physalis alkekengi var. franchetii, a traditional Chinese herbal medicine named Jindenglong, which has long been used for the treatment of sore throat, hepatitis, and tumors in China. In the present study, we firstly investigated the effects of PA on proliferation and cell cycle distribution of the human non-small cell lung cancer (NSCLC) A549 cell line, and the potential mechanisms involved. Here, PA inhibited cell growth in dose- and time-dependent manners. Treatment of A549 cells with 28.4 μM PA for 24 h resulted in approximately 50 % cell death. PA increased the amount of intracellular ROS and the proportion of cells in G2/M. G2/M arrest was attenuated by the addition of ROS scavenger NAC. ERK and P38 were triggered by PA through phosphorylation in a time-dependent manner. The phosphorylation of ERK and P38 were not attenuated by the addition of NAC, but the use of the p38 inhibitor could reduce, at least in part, PA-induced ROS and the proportion of cells in G2/M. PA induces G2/M cell cycle arrest in A549 cells involving in the p38 MAPK/ROS pathway. This study suggests that PA might be a promising therapeutic agent against NSCLC.

  4. Effect of Tongxinluo on Podocyte Apoptosis via Inhibition of Oxidative Stress and P38 Pathway in Diabetic Rats

    PubMed Central

    Cui, Fangqiang; Zhao, Wenjing; Zou, Dawei; Wu, Xiaoming; Tian, Nianxiu; Wang, Xiaolei; Liu, Jing; Tong, Yu

    2016-01-01

    Diabetic nephropathy (DN) has been the leading cause of end-stage renal disease (ESRD). Podocyte apoptosis is a main mechanism of progression of DN. It has been demonstrated that activated P38 and caspase-3 induced by oxidative stress mainly account for increased podocyte apoptosis and proteinuria in DN. Meanwhile, Tongxinluo (TXL) can ameliorate renal structure disruption and dysfunction in DN patients in our clinical practice. However, the effect of TXL on podocyte apoptosis and P38 pathway remains unclear. To explore the effect of TXL on podocyte apoptosis and its molecular mechanism in DN, our in vivo and in vitro studies were performed. TXL attenuated oxidative stress in podocyte in DN in our in vivo and in vitro studies. Moreover, TXL inhibited the activation of P38 and caspase-3. Bcl-2 and Bax expression was partially restored by TXL treatment in our in vivo and in vitro studies. More importantly, TXL decreased podocyte apoptosis in diabetic rats and high glucose cultured podocyte. In conclusion, TXL protects podocyte from apoptosis in DN, partially through its antioxidant effect and inhibiting of the activation of P38 and caspase-3. PMID:27672400

  5. Activation of villous trophoblastic p38 and ERK1/2 signaling pathways in preterm preeclampsia and HELLP syndrome.

    PubMed

    Szabo, Szilvia; Mody, Meera; Romero, Roberto; Xu, Yi; Karaszi, Katalin; Mihalik, Noemi; Xu, Zhonghui; Bhatti, Gaurav; Fule, Tibor; Hupuczi, Petronella; Krenacs, Tibor; Rigo, Janos; Tarca, Adi L; Hassan, Sonia S; Chaiworapongsa, Tinnakorn; Kovalszky, Ilona; Papp, Zoltan; Than, Nandor Gabor

    2015-07-01

    Preterm preeclampsia is associated with the failure of trophoblast invasion, placental hypoxic/ischemic injury and the release of toxic substances, which promote the terminal pathway of preeclampsia. In term preeclampsia, factors yet unknown trigger the placenta to induce the terminal pathway. The contribution of the villous trophoblast to these pathologic events has not been fully elucidated. Here we aimed to study how stress and signaling pathways influence trophoblastic functions in various subforms of preeclampsia. Tissue microarrays (TMAs) were constructed from placentas obtained from pregnant women in the following groups: 1-2) preterm preeclampsia with (n = 8) or without (n = 7) HELLP syndrome; 3) late-onset preeclampsia (n = 8); 4-5) preterm (n = 5) and term (n = 9) controls. TMA slides were stained for phosphorylated Akt-1, ERK1/2, JNK, and p38 kinases, and trophoblastic immunostainings were semi-quantitatively evaluated. BeWo cells were kept in various stress conditions, and the expression of FLT1, GCM1, LEP, and PGF was profiled by qRT-PCR, while Akt-1, ERK1/2, JNK, and p38 kinase activities were measured with phospho-kinase immunoassays. We found that: 1) Placental LEP and FLT1 expression was up-regulated in preterm preeclampsia with or without HELLP syndrome compared to controls; 2) Mean pp38 immunoscore was higher in preterm preeclampsia, especially in cases with HELLP syndrome, than in controls. 3) Mean pERK1/2 immunoscore was higher in preterm preeclampsia with HELLP syndrome than in controls. 4) In BeWo cells, ischemia up-regulated LEP expression, and it increased JNK and decreased ERK1/2 activity. 5) Hypoxia up-regulated FLT1 and down-regulated PGF expression, and it increased ERK1/2, JNK and p38 activity. 6) IL-1β treatment down-regulated PGF expression, and it increased JNK and p38 activity. 7) The p38 signaling pathway had the most impact on LEP, FLT1 and PGF expression. In conclusion, hypoxic and ischemic stress, along

  6. BX-795 inhibits HSV-1 and HSV-2 replication by blocking the JNK/p38 pathways without interfering with PDK1 activity in host cells

    PubMed Central

    Su, Ai-rong; Qiu, Min; Li, Yan-lei; Xu, Wen-tao; Song, Si-wei; Wang, Xiao-hui; Song, Hong-yong; Zheng, Nan; Wu, Zhi-wei

    2017-01-01

    BX-795 is an inhibitor of 3-phosphoinositide-dependent kinase 1 (PDK1), but also a potent inhibitor of the IKK-related kinase, TANKbinding kinase 1 (TBK1) and IKKɛ. In this study we attempted to elucidate the molecular mechanism(s) underlying the inhibition of BX-795 on Herpes simplex virus (HSV) replication. HEC-1-A or Vero cells were treated with BX-795 and infected with HSV-1 or HSV-2 for different periods. BX-795 (3.125-25 μmol/L) dose-dependently suppressed HSV-2 replication, and displayed a low cytotoxicity to the host cells. BX-795 treatment dose-dependently suppressed the expression of two HSV immediate-early (IE) genes (ICP0 and ICP27) and the late gene (gD) at 12 h postinfection. HSV-2 infection resulted in the activation of PI3K and Akt in the host cells, and BX-795 treatment inhibited HSV-2-induced Akt phosphorylation and activation. However, the blockage of PI3K/Akt/mTOR with LY294002 and rapamycin did not affect HSV-2 replication. HSV-2 infection increased the phosphorylation of JNK and p38, and reduced ERK phosphorylation at 8 h postinfection in the host cells; BX-795 treatment inhibited HSV-2-induced activation of JNK and p38 MAP kinase as well as the phosphorylation of c-Jun and ATF-2, the downstream targets of JNK and p38 MAP kinase. Furthermore, SB203580 (a p38 inhibitor) or SP600125 (a JNK inhibitor) dose-dependently inhibited the viral replication in the host cells, whereas PD98059 (an ERK inhibitor) was not effective. Moreover, BX-795 blocked PMA-stimulated c-Jun activation as well as HSV-2-mediated c-Jun nuclear translocation. BX-795 dose-dependently inhibited HSV-2, PMA, TNF-α-stimulated AP-1 activation, but not HSV-induced NF-κB activation. Overexpression of p38/JNK attenuated the inhibitory effect of BX-795 on HSV replication. BX-795 completely blocked HSV-2-induced MKK4 phosphorylation, suggesting that BX-795 acting upstream of JNK and p38 MAP kinase. In conclusion, this study identifies the anti-HSV activity of BX-795 and its

  7. Allicin Alleviates Inflammation of Trinitrobenzenesulfonic Acid-Induced Rats and Suppresses P38 and JNK Pathways in Caco-2 Cells

    PubMed Central

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

    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

  8. 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

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

    PubMed Central

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

    2016-01-01

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

  10. 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

  11. RhoA-ROCK and p38MAPK-MSK1 mediate vitamin D effects on gene expression, phenotype, and Wnt pathway in colon cancer cells.

    PubMed

    Ordóñez-Morán, Paloma; Larriba, María Jesús; Pálmer, Héctor G; Valero, Ruth A; Barbáchano, Antonio; Duñach, Mireia; de Herreros, Antonio García; Villalobos, Carlos; Berciano, María Teresa; Lafarga, Miguel; Muñoz, Alberto

    2008-11-17

    The active vitamin D metabolite 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) inhibits proliferation and promotes differentiation of colon cancer cells through the activation of vitamin D receptor (VDR), a transcription factor of the nuclear receptor superfamily. Additionally, 1,25(OH)(2)D(3) has several nongenomic effects of uncertain relevance. We show that 1,25(OH)(2)D(3) induces a transcription-independent Ca(2+) influx and activation of RhoA-Rho-associated coiled kinase (ROCK). This requires VDR and is followed by activation of the p38 mitogen-activated protein kinase (p38MAPK) and mitogen- and stress-activated kinase 1 (MSK1). As shown by the use of chemical inhibitors, dominant-negative mutants and small interfering RNA, RhoA-ROCK, and p38MAPK-MSK1 activation is necessary for the induction of CDH1/E-cadherin, CYP24, and other genes and of an adhesive phenotype by 1,25(OH)(2)D(3). RhoA-ROCK and MSK1 are also required for the inhibition of Wnt-beta-catenin pathway and cell proliferation. Thus, the action of 1,25(OH)(2)D(3) on colon carcinoma cells depends on the dual action of VDR as a transcription factor and a nongenomic activator of RhoA-ROCK and p38MAPK-MSK1.

  12. 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

  13. SDF-1/CXCR7 axis enhances ovarian cancer cell invasion by MMP-9 expression through p38 MAPK pathway.

    PubMed

    Yu, Yuecheng; Li, Hongmei; Xue, Baoyao; Jiang, Xia; Huang, Kan; Ge, Junli; Zhang, Hongju; Chen, Biliang

    2014-08-01

    Ovarian cancer is an aggressive gynecological malignancy with high metastatic potential. Recently, the CXC receptor (CXCR7) has been identified as a new receptor for stromal-derived factor-1 (SDF-1), and exerts important roles in cancer development. However, its effect on ovarian cancer and the underlying mechanism remain unknown. In this study, we detected abundant CXCR7 expression in ovarian cancer tissues and cells. Moreover, SDF-1 induced dramatically upregulation of CXCR7 mRNA and protein levels, indicating that the SDF-1/CXCR7 axis existed in ovarian cancer. Further analysis confirmed that SDF-1 enhanced cell adhesion and subsequent invasion, which were significantly attenuated when pretreated with CXCR7 small interference RNA (siRNA), indicating the critical function of SDF-1/CXCR7 in cell invasion. Further mechanistic analysis indicated that SDF-1/CXCR7 enhanced cell invasion by matrix metalloproteinase (MMP)-9, as pretreatment with MMP-9 siRNA significantly abrogated a number of invading cells. Additionally, SDF-1/CXCR7 induced phosphorylation of the p38 MAPK pathway, which was accounted for MMP-9 expression as preconditioning with the p38 MAPK inhibitor SB203580 obviously decreased MMP-9 expression. Together, our data implied that SDF-1/CXCR7 enhanced ovarian cancer cell invasion by MMP-9 expression through the p38 MAPK pathway. Thus, these findings confirmed the critical role of SDF-1/CXCR7 during the pathological processes of ovarian cancer and supported its potential targets for further development of antiovarian cancer therapy.

  14. Fibroblast growth factor 18 promotes proliferation and migration of H460 cells via the ERK and p38 signaling pathways.

    PubMed

    Chen, Taotao; Gong, Weiyue; Tian, Haishan; Wang, Haijun; Chu, Shenghui; Ma, Jisheng; Yang, Huanhuan; Cheng, Jiliang; Liu, Min; Li, Xiaokun; Jiang, Chao

    2017-02-01

    Recently, fibroblast growth factor 18 (FGF18) expression was reported to be upregulated in colon cancer and ovarian cancer, and increased expression of FGF18 mRNA and protein is associated with tumor progression and poor overall survival in patients; however, its role in lung cancer remains to be explored. In the present study, the effect and underlying molecular mechanisms of FGF18 on H460 cells were investigated. Cell proliferation and cell cycle alterations were detected using a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and flow cytometry. A wound healing assay was conducted to detect cell migration. Reverse transcription-quantitative polymerase chain reaction and western blotting were performed to measure extracellular signal-regulated kinase (ERK), p38 and matrix metalloproteinase 26 (MMP26) expression. Knockdown of FGF18 using short interfering RNA (siRNA-FGF18) suppressed H460 cell proliferation, inhibited cell migration via the downregulation of MMP26 levels, with siRNA-FGF18 additionally inhibiting the ERK and p38 signaling pathway. The present study indicates that FGF18 serves an essential role in the growth and migration of non-small cell lung cancer (NSCLC) cells by regulating the ERK, p38 signaling pathways and MMP26 protein levels, suggesting that FGF18 may be a potential molecular drug target for the treatment NSCLC.

  15. Selaginella tamariscina (Beauv.) possesses antimetastatic effects on human osteosarcoma cells by decreasing MMP-2 and MMP-9 secretions via p38 and Akt signaling pathways.

    PubMed

    Yang, Jia-Sin; Lin, Chiao-Wen; Hsieh, Yih-Shou; Cheng, Hsin-Lin; Lue, Ko-Huang; Yang, Shun-Fa; Lu, Ko-Hsiu

    2013-09-01

    Selaginella tamariscina is a traditional medicinal plant for treatment of some advanced cancers in the Orient. However, the effect of S. tamariscina on metastasis of osteosarcoma and the underlying mechanism remain unclear. We tested the hypothesis that S. tamariscina suppresses cellular motility, invasion and migration and also investigated its signaling pathways. This study demonstrates that S. tamariscina, at a range of concentrations (from 0 to 50 μg/mL), concentration-dependently inhibited the migration/invasion capacities of three osteosarcoma cell lines without cytotoxic effects. Zymographic and western blot analyses revealed that S. tamariscina inhibited the matrix metalloproteinase (MMP)-2 and MMP-9 enzyme activity, as well as protein expression. Western blot analysis also showed that S. tamariscina inhibits phosphorylation of p38 and Akt. Furthermore, SB203580 (p38 inhibitor) and LY294002 (PI3K inhibitor) showed the similar effects as S. tamariscina in U2OS cells. In conclusion, S. tamariscina possesses an antimetastatic activity in osteosarcoma cells by down-regulating MMP-2 and MMP-9 secretions and increasing TIMP-1 and TIMP-2 expressions through p38 and Akt-dependent pathways. S. tamariscina may be a powerful candidate to develop a preventive agent for osteosarcoma metastasis.

  16. 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.

  17. Exendin-4 protects endothelial cells from lipoapoptosis by PKA, PI3K, eNOS, p38 MAPK, and JNK pathways.

    PubMed

    Erdogdu, Ozlem; Eriksson, Linnéa; Xu, Hua; Sjöholm, Ake; Zhang, Qimin; Nyström, Thomas

    2013-04-01

    Experimental studies have indicated that endothelial cells play an important role in maintaining vascular homeostasis. We previously reported that human coronary artery endothelial cells (HCAECs) express the glucagon-like peptide 1 (GLP1) receptor and that the stable GLP1 mimetic exendin-4 is able to activate the receptor, leading to increased cell proliferation. Here, we have studied the effect of exendin-4 and native GLP1 (7-36) on lipoapoptosis and its underlying mechanisms in HCAECs. Apoptosis was assessed by DNA fragmentation and caspase-3 activation, after incubating cells with palmitate. Nitric oxide (NO) and reactive oxidative species (ROS) were analyzed. GLP1 receptor activation, PKA-, PI3K/Akt-, eNOS-, p38 MAPK-, and JNK-dependent pathways, and genetic silencing of transfection of eNOS were also studied. Palmitate-induced apoptosis stimulated cells to release NO and ROS, concomitant with upregulation of eNOS, which required activation of p38 MAPK and JNK. Exendin-4 restored the imbalance between NO and ROS production in which ROS production decreased and NO production was further augmented. Incubation with exendin-4 and GLP1 (7-36) protected HCAECs against lipoapoptosis, an effect that was blocked by PKA, PI3K/Akt, eNOS, p38 MAPK, and JNK inhibitors. Genetic silencing of eNOS also abolished the anti-apoptotic effect afforded by exendin-4. Our results support the notion that GLP1 receptor agonists restore eNOS-induced ROS production due to lipotoxicity and that such agonists protect against lipoapoptosis through PKA-PI3K/Akt-eNOS-p38 MAPK-JNK-dependent pathways via a GLP1 receptor-dependent mechanism.

  18. A sestrin-dependent Erk-Jnk-p38 MAPK activation complex inhibits immunity during aging.

    PubMed

    Lanna, Alessio; Gomes, Daniel C O; Muller-Durovic, Bojana; McDonnell, Thomas; Escors, David; Gilroy, Derek W; Lee, Jun Hee; Karin, Michael; Akbar, Arne N

    2017-03-01

    Mitogen-activated protein kinases (MAPKs) including Erk, Jnk and p38 regulate diverse cellular functions and are thought to be controlled by independent upstream activation cascades. Here we show that the sestrins bind to and coordinate simultaneous Erk, Jnk and p38 MAPK activation in T lymphocytes within a new immune-inhibitory complex (sestrin-MAPK activation complex (sMAC)). Whereas sestrin ablation resulted in broad reconstitution of immune function in stressed T cells, inhibition of individual MAPKs allowed only partial functional recovery. T cells from old humans (>65 years old) or mice (16-20 months old) were more likely to form the sMAC, and disruption of this complex restored antigen-specific functional responses in these cells. Correspondingly, sestrin deficiency or simultaneous inhibition of all three MAPKs enhanced vaccine responsiveness in old mice. Thus, disruption of sMAC provides a foundation for rejuvenating immunity during aging.

  19. p38 Mitogen-Activated Protein Kinase-Dependent and -Independent Signaling of mRNA Stability of AU-Rich Element-Containing Transcripts

    PubMed Central

    Frevel, Mathias A. E.; Bakheet, Tala; Silva, Aristobolo M.; Hissong, John G.; Khabar, Khalid S. A.; Williams, Bryan R. G.

    2003-01-01

    Adenylate/uridylate-rich element (ARE)-mediated mRNA turnover is an important regulatory component of gene expression for innate and specific immunity, in the hematopoietic system, in cellular growth regulation, and for many other cellular processes. This diversity is reflected in the distribution of AREs in the human genome, which we have established as a database of more than 900 ARE-containing genes that may utilize AREs as a means of controlling cellular mRNA levels. The p38 mitogen-activated protein kinase (MAP kinase) pathway has been implicated in regulating the stability of nine ARE-containing transcripts. Here we explored the entire spectrum of ARE-containing genes for p38-dependent regulation of ARE-mediated mRNA turnover with a custom cDNA array containing probes for 950 ARE mRNAs. The human monocytic cell line THP-1 treated with lipopolysaccharide (LPS) was used as a reproducible cellular model system that allowed us to precisely control the conditions of mRNA induction and decay in the absence and presence of the p38 inhibitor SB203580. This approach allowed us to establish an LPS-induced ARE mRNA expression profile in human monocytes and determine the half-lives of 470 AU-rich mRNAs. Most importantly, we identified 42 AU-rich genes, previously unrecognized, that show p38-dependent mRNA stabilization. In addition to a number of cytokines, several interesting novel AU-rich transcripts likely to play a role in macrophage activation by LPS exhibited p38-dependent transcript stabilization, including macrophage-specific colony-stimulating factor 1, carbonic anhydrase 2, Bcl2, Bcl2-like 2, and nuclear factor erythroid 2-like 2. Finally, the identification of the p38-dependent upstream activator MAP kinase kinase 6 as a member of this group identifies a positive feedback loop regulating macrophage signaling via p38 MAP kinase-dependent transcript stabilization. PMID:12509443

  20. 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

  1. Rutin Protects against Pirarubicin-Induced Cardiotoxicity through TGF-β1-p38 MAPK Signaling Pathway

    PubMed Central

    Wang, Yadi; Zhang, Yang; Sun, Bo; Tong, Qing

    2017-01-01

    We investigated the potential protective effect of rutinum (RUT) against pirarubicin- (THP-) induced cardiotoxicity. THP was used to induce toxicity in rat H9c2 cardiomyoblasts. Positive control cells were pretreated with a cardioprotective agent dexrazoxane (DZR) prior to treatment with THP. Some of the cells were preincubated with RUT and a p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580, both individually and in combination, prior to THP exposure. At a dose range of 30–70 μM, RUT significantly prevented THP-induced reduction in cell viability; the best cardioprotective effect was observed at a dose of 50 μM. Administration of RUT and SB203580, both individually as well as in combination, suppressed the elevation of intracellular ROS, inhibited cell apoptosis, and reversed the THP-induced upregulation of TGF-β1, p-p38 MAPK, cleaved Caspase-9, Caspase-7, and Caspase-3. A synergistic effect was observed on coadministration of RUT and SB203580. RUT protected against THP-induced cardiotoxicity by inhibition of ROS generation and suppression of cell apoptosis. The cardioprotective effect of RUT appears to be associated with the modulation of the TGF-β1-p38 MAPK signaling pathway. PMID:28367221

  2. Bacillus anthracis peptidoglycan stimulates an inflammatory response in monocytes through the p38 mitogen-activated protein kinase pathway.

    PubMed

    Langer, Marybeth; Malykhin, Alexander; Maeda, Kenichiro; Chakrabarty, Kaushik; Williamson, Kelly S; Feasley, Christa L; West, Christopher M; Metcalf, Jordan P; Coggeshall, K Mark

    2008-01-01

    We hypothesized that the peptidoglycan component of B. anthracis may play a critical role in morbidity and mortality associated with inhalation anthrax. To explore this issue, we purified the peptidoglycan component of the bacterial cell wall and studied the response of human peripheral blood cells. The purified B. anthracis peptidoglycan was free of non-covalently bound protein but contained a complex set of amino acids probably arising from the stem peptide. The peptidoglycan contained a polysaccharide that was removed by mild acid treatment, and the biological activity remained with the peptidoglycan and not the polysaccharide. The biological activity of the peptidoglycan was sensitive to lysozyme but not other hydrolytic enzymes, showing that the activity resides in the peptidoglycan component and not bacterial DNA, RNA or protein. B. anthracis peptidoglycan stimulated monocytes to produce primarily TNFalpha; neutrophils and lymphocytes did not respond. Peptidoglycan stimulated monocyte p38 mitogen-activated protein kinase and p38 activity was required for TNFalpha production by the cells. We conclude that peptidoglycan in B. anthracis is biologically active, that it stimulates a proinflammatory response in monocytes, and uses the p38 kinase signal transduction pathway to do so. Given the high bacterial burden in pulmonary anthrax, these findings suggest that the inflammatory events associated with peptidoglycan may play an important role in anthrax pathogenesis.

  3. Bacillus anthracis Peptidoglycan Stimulates an Inflammatory Response in Monocytes through the p38 Mitogen-Activated Protein Kinase Pathway

    PubMed Central

    Langer, Marybeth; Malykhin, Alexander; Maeda, Kenichiro; Chakrabarty, Kaushik; Williamson, Kelly S.; Feasley, Christa L.; West, Christopher M.; Metcalf, Jordan P.; Coggeshall, K. Mark

    2008-01-01

    We hypothesized that the peptidoglycan component of B. anthracis may play a critical role in morbidity and mortality associated with inhalation anthrax. To explore this issue, we purified the peptidoglycan component of the bacterial cell wall and studied the response of human peripheral blood cells. The purified B. anthracis peptidoglycan was free of non-covalently bound protein but contained a complex set of amino acids probably arising from the stem peptide. The peptidoglycan contained a polysaccharide that was removed by mild acid treatment, and the biological activity remained with the peptidoglycan and not the polysaccharide. The biological activity of the peptidoglycan was sensitive to lysozyme but not other hydrolytic enzymes, showing that the activity resides in the peptidoglycan component and not bacterial DNA, RNA or protein. B. anthracis peptidoglycan stimulated monocytes to produce primarily TNFα; neutrophils and lymphocytes did not respond. Peptidoglycan stimulated monocyte p38 mitogen-activated protein kinase and p38 activity was required for TNFα production by the cells. We conclude that peptidoglycan in B. anthracis is biologically active, that it stimulates a proinflammatory response in monocytes, and uses the p38 kinase signal transduction pathway to do so. Given the high bacterial burden in pulmonary anthrax, these findings suggest that the inflammatory events associated with peptidoglycan may play an important role in anthrax pathogenesis. PMID:19002259

  4. Exposure to p,p′-DDE Induces Morphological Changes and Activation of the PKCα-p38-C/EBPβ Pathway in Human Promyelocytic HL-60 Cells

    PubMed Central

    Torres-Avilés, Nallely A.; Albores-García, Damaris; Luna, Ana L.; Moreno-Galván, Monica; Salgado-Bustamante, Mariana; Portales-Pérez, Diana Patricia

    2016-01-01

    Dichlorodiphenyldichloroethylene (p,p′-DDE), the most persistent metabolite of dichlorodiphenyltrichloroethane (DDT), is still present in the human population. Both are present in the bone marrow of patients with bone marrow disorders, but thus far there are no studies that assess the capability of p,p′-DDE to affect myeloid cells. The aim of this study was to determine the effect of p,p′-DDE on promyelocytic cell differentiation and intracellular pathways related to this event. p,p′-DDE induced morphological changes compatible with promyelocytic differentiation in a concentration-dependent manner. The p,p′-DDE effect on [Ca2+]i, C/EBPβ protein levels, PKCα and p38 activation, and the role of oxidative stress or PLA2 was assayed. Exposure to 1.9 μg/mL of p,p′-DDE increased [Ca2+]i, PKCα, p38, and C/EBPβ protein levels; the increase of nuclear C/EBPβ protein was dependent on p38. PKCα phosphorylation was dependent on PLA2 and p,p′-DDE-induced oxidative stress. p38 phosphorylation induced by p,p′-DDE was dependent on PLA2, PKC activation, and oxidative stress. These effects of p,p′-DDE at concentrations found in human bone marrow may induce alterations in immature myeloid cells and could affect their cellular homeostasis. In order to establish the risk from exposure to p,p′-DDE on the development of bone marrow disorders in humans, these effects deserve further study. PMID:27833915

  5. Hypoglycemic Effect of Opuntia ficus-indica var. saboten Is Due to Enhanced Peripheral Glucose Uptake through Activation of AMPK/p38 MAPK Pathway.

    PubMed

    Leem, Kang-Hyun; Kim, Myung-Gyou; Hahm, Young-Tae; Kim, Hye Kyung

    2016-12-09

    Opuntia ficus-indica var. saboten (OFS) has been used in traditional medicine for centuries to treat several illnesses, including diabetes. However, detailed mechanisms underlying hypoglycemic effects remain unclear. In this study, the mechanism underlying the hypoglycemic activity of OFS was evaluated using in vitro and in vivo systems. OFS treatment inhibited α-glucosidase activity and intestinal glucose absorption assessed by Na⁺-dependent glucose uptake using brush border membrane vesicles. AMP-activated protein kinase (AMPK) is widely recognized as an important regulator of glucose transport in skeletal muscle, and p38 mitogen-activated protein kinase (MAPK) has been proposed to be a component of AMPK-mediated signaling. In the present study, OFS dose-dependently increased glucose uptake in L6 muscle cells. The AMPK and p38 MAPK phosphorylations were stimulated by OFS, and inhibitors of AMPK (compound C) and p38 MAPK (SB203580) abolished the effects of OFS. Furthermore, OFS increased glucose transporter 4 (GLUT4) translocation to the plasma membrane. OFS administration (1 g/kg and 2 g/kg body weight) in db/db mice dose-dependently ameliorated hyperglycemia, hyperinsulinemia, and glucose tolerance. Insulin resistance assessed by homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index were also dose-dependently improved with OFS treatment. OFS administration improved pancreatic function through increased β-cell mass in db/db mice. These findings suggest that OFS acts by inhibiting glucose absorption from the intestine and enhancing glucose uptake from insulin-sensitive muscle cells through the AMPK/p38 MAPK signaling pathway.

  6. Hypoglycemic Effect of Opuntia ficus-indica var. saboten Is Due to Enhanced Peripheral Glucose Uptake through Activation of AMPK/p38 MAPK Pathway

    PubMed Central

    Leem, Kang-Hyun; Kim, Myung-Gyou; Hahm, Young-Tae; Kim, Hye Kyung

    2016-01-01

    Opuntia ficus-indica var. saboten (OFS) has been used in traditional medicine for centuries to treat several illnesses, including diabetes. However, detailed mechanisms underlying hypoglycemic effects remain unclear. In this study, the mechanism underlying the hypoglycemic activity of OFS was evaluated using in vitro and in vivo systems. OFS treatment inhibited α-glucosidase activity and intestinal glucose absorption assessed by Na+-dependent glucose uptake using brush border membrane vesicles. AMP-activated protein kinase (AMPK) is widely recognized as an important regulator of glucose transport in skeletal muscle, and p38 mitogen-activated protein kinase (MAPK) has been proposed to be a component of AMPK-mediated signaling. In the present study, OFS dose-dependently increased glucose uptake in L6 muscle cells. The AMPK and p38 MAPK phosphorylations were stimulated by OFS, and inhibitors of AMPK (compound C) and p38 MAPK (SB203580) abolished the effects of OFS. Furthermore, OFS increased glucose transporter 4 (GLUT4) translocation to the plasma membrane. OFS administration (1 g/kg and 2 g/kg body weight) in db/db mice dose-dependently ameliorated hyperglycemia, hyperinsulinemia, and glucose tolerance. Insulin resistance assessed by homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index were also dose-dependently improved with OFS treatment. OFS administration improved pancreatic function through increased β-cell mass in db/db mice. These findings suggest that OFS acts by inhibiting glucose absorption from the intestine and enhancing glucose uptake from insulin-sensitive muscle cells through the AMPK/p38 MAPK signaling pathway. PMID:27941667

  7. 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.

  8. Sesamin inhibits lipopolysaccharide-induced proliferation and invasion through the p38-MAPK and NF-κB signaling pathways in prostate cancer cells.

    PubMed

    Xu, Peiyuan; Cai, Fei; Liu, Xiaofei; Guo, Lele

    2015-06-01

    Sesamin, a lipid-soluble lignan, is one of the major constituents of sesame. Previous studies have reported that sesamin induces growth inhibition in human cancer cells, particularly prostate cancer cells. In the present study, we mainly explored the mechanism underlying the protective effect of sesamin on prostate cancer cell proliferation and invasion induced by lipopolysaccharide (LPS). We found that the proliferation of PC3 cells, as determined using the MTT assay, and the expression of cyclin D1, COX-2, Bcl-2 and survivin proteins elevated by LPS were distinctly inhibited by sesamin in a dose-dependent manner. Meanwhile, the ability of PC3 cell invasion, as determined using the Transwell assay and the expression of matrix metalloproteinase 9 (MMP-9), intercellular adhesion molecule-1 (ICAM-1) and vascular endothelial growth factor (VEGF) proteins increased by LPS were obviously reduced by sesamin in a dose-dependent manner. In addition, the accumulation of TGF-α and interleukin-6 (IL-6) production induced by LPS in the culture supernatant was found to be decreased dose-dependently with sesamin pretreatment in PC3 cells using the enzyme-linked immunosorbent assay (ELISA) kit. Furthermore, phosphorylation of the p38 protein and nuclear factor (NF)-κB activity in the PC3 cells were enhanced by LPS and further inhibited with sesamin, SB203580 pretreatment or p38-siRNA transfection, respectively. Sesamin or SB203580 pretreatment obviously inhibited PC3 cells-derived tumor growth induced by LPS in vivo. Taken together, these results suggest that the potential ability of sesamin to downregulate the secretion of cytokines and the expression of cell proliferative- and invasive-related gene products induced by LPS was shown to be via the p38 mitogen-activated protein kinase (p38-MAPK) and NF-κB signaling pathways, which may be one of the mechanisms of the anticancer activity of this sesamin agent in prostate cancer cells.

  9. 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

    2016-09-06

    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.

  10. Elevated COX-2 Expression Promotes Angiogenesis Through EGFR/p38-MAPK/Sp1-Dependent Signalling in Pancreatic Cancer.

    PubMed

    Hu, Hai; Han, Ting; Zhuo, Meng; Wu, Lei-Lei; Yuan, Cuncun; Wu, Lixia; Lei, Wang; Jiao, Feng; Wang, Li-Wei

    2017-03-28

    Cyclooxygenase-2 (COX-2) was stated to be overexpression in various human malignancies associating with angiogenesis, metastasis and chemoresistence. Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease displaying many of these characteristics. A common abnormality of PDAC is overexpression of specificity protein-1 (Sp1), which was said to correlate with malignant phenotypes of human cancers. Using RNA-seq data from The Cancer Genome Atlas (TCGA), we found that Sp1 expression was positively correlated with that of COX-2 in PDAC, and that the inhibition or overexpression of Sp1 in PDAC cells leads to decreased or elevated COX-2 expression. Luciferase reporter gene and chromatin immunoprecipitation (ChIP) assays revealed that elevated transcription of COX-2 requires Sp1 binding to sequence positions around -245/-240 of COX-2 promoter. Activated epidermal growth factor receptor (EGFR) and downstream p38 mitogen-activated protein kinase (p38-MAPK) were also profoundly altered in PDAC. The inhibition of EGFR/p38-MAPK signaling resulted in reduced Sp1 activation, decreased COX-2 and vascular endothelial growth factor (VEGF) expression. Thus, Sp1 could transcriptionally activate COX-2 expression in a process relies on activated EGFR/p38-MAPK signaling. Finally, we found that the inhibition of COX-2 leads to decreased angiogenesis in a process dependent on VEGF, which link COX-2 to angiogenesis in PDAC.

  11. p38 MAPK mediates renal tubular cell TNF-alpha production and TNF-alpha-dependent apoptosis during simulated ischemia.

    PubMed

    Meldrum, K K; Meldrum, D R; Hile, K L; Yerkes, E B; Ayala, A; Cain, M P; Rink, R C; Casale, A J; Kaefer, M A

    2001-08-01

    Ischemia causes renal tubular cell loss through apoptosis; however, the mechanisms of this process remain unclear. Using the renal tubular epithelial cell line LLC-PK(1), we developed a model of simulated ischemia (SI) to investigate the role of p38 MAPK (mitogen-activated protein kinase) in renal cell tumor necrosis factor-alpha (TNF-alpha) mRNA production, protein bioactivity, and apoptosis. Results demonstrate that 60 min of SI induced maximal TNF-alpha mRNA production and bioactivity. Furthermore, 60 min of ischemia induced renal tubular cell apoptosis at all substrate replacement time points examined, with peak apoptotic cell death occurring after either 24 or 48 h. p38 MAPK inhibition abolished TNF-alpha mRNA production and TNF-alpha bioactivity, and both p38 MAPK inhibition and TNF-alpha neutralization (anti-porcine TNF-alpha antibody) prevented apoptosis after 60 min of SI. These results constitute the initial demonstration that 1) renal tubular cells produce TNF-alpha mRNA and biologically active TNF-alpha and undergo apoptosis in response to SI, and 2) p38 MAPK mediates renal tubular cell TNF-alpha production and TNF-alpha-dependent apoptosis after SI.

  12. Rit-mediated Stress Resistance Involves a p38-Mitogen- and Stress-activated Protein Kinase 1 (MSK1)-dependent cAMP Response Element-binding Protein (CREB) Activation Cascade*

    PubMed Central

    Shi, Geng-Xian; Cai, Weikang; Andres, Douglas A.

    2012-01-01

    The cAMP response element (CRE)-binding protein (CREB) is a key regulatory factor of gene transcription, and plays an essential role in development of the central nervous system and for neuroprotection. Multiple signaling pathways have been shown to contribute to the regulation of CREB-dependent transcription, including both ERK and p38 mitogen-activated protein (MAP) kinases cascades. Recent studies have identified the Ras-related small G-protein, Rit, as a central regulator of a p38-MK2-HSP27 signaling cascade that functions as a critical survival mechanism for cells adapting to stress. Here, we examine the contribution of Rit-p38 signaling to the control of stress-dependent gene transcription. Using a pheochromocytoma cell model, we find that a novel Rit-p38-MSK1/2 pathway plays a critical role in stress-mediated CREB activation. RNAi-mediated Rit silencing, or inhibition of p38 or MSK1/2 kinases, was found to disrupt stress-mediated CREB-dependent transcription, resulting in increased cell death. Furthermore, ectopic expression of active Rit stimulates CREB-Ser133 phosphorylation, induces expression of the anti-apoptotic Bcl-2 and BclXL proteins, and promotes cell survival. These data indicate that the Rit-p38-MSK1/2 signaling pathway may have an important role in the stress-dependent regulation of CREB-dependent gene expression. PMID:23038261

  13. Involvement of the p38 MAPK signaling pathway in S-phase cell-cycle arrest induced by Furazolidone in human hepatoma G2 cells.

    PubMed

    Sun, Yu; Tang, Shusheng; Jin, Xi; Zhang, Chaoming; Zhao, Wenxia; Xiao, Xilong

    2013-12-01

    Given the previously described essential role for the p38 mitogen-activation protein kinase (p38 MAPK) signaling pathway in human hepatoma G2 cells (HepG2), we undertook the present study to investigate the role of the p38 MAPK signaling pathway in cell-cycle arrest induced by Furazolidone (FZD). The aim of this study was to determine the effects of FZD on HepG2 cells by activating and inhibiting the p38 MAPK signaling pathway. The cell cycle and proliferation of HepG2 cells treated with FZD were detected by flow cytometry and MTT assay in the presence or absence of p38 MAPK inhibitors (SB203580), respectively. Cyclin D1, cyclin D3 and CDK6 were detected by quantitative real-time PCR and western blot analysis. Our data showed that p38 MAPK became phosphorylated after stimulation with FZD. Activation of p38 MAPK could arise S-phase cell-cycle arrest and suppress cell proliferation. Simultaneously, inhibition of the p38 MAPK signaling pathway significantly prevented S-phase cell-cycle arrest, increased the percentage of cell viability and decreased the expression of cyclin D1, cyclin D3 and CDK6. These results demonstrated that FZD arose S-phase cell-cycle arrest via activating the p38 MAPK signaling pathway in HepG2 cells. Cyclin D1, cyclin D3 and CDK6 are target genes functioning at the downstream of p38 MAPK in HepG2 cells induced by FZD.

  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 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

  15. 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

  16. Curcumol Inhibits Growth and Induces Apoptosis of Colorectal Cancer LoVo Cell Line via IGF-1R and p38 MAPK Pathway

    PubMed Central

    Wang, Juan; Huang, Fengxiang; Bai, Zhun; Chi, Bixia; Wu, Jiacai; Chen, Xu

    2015-01-01

    Curcumol, isolated from the traditional medical plant Rhizoma Curcumae, is the bioactive component of Zedoary oil, whose potential anti-tumor effect has attracted considerable attention in recent years. Though many researchers have reported curcumol and its bioactivity, the potential molecular mechanism for its anti-cancer effect in colorectal cancer LoVo cells still remains unclear. In the present study, we found that curcumol showed growth inhibition and induced apoptosis of LoVo cells in a dose- and time-dependent manner. The occurrence of its proliferation inhibition and apoptosis came with suppression of IGF-1R expression, and then increased the phosphorylation of p38 mitogen activated protein kinase (MAPK), which might result in a cascade response by inhibiting the CREB survival pathway and finally triggered Bax/Bcl-2 and poly(ADP-ribose) polymerase 1 (PARP-1) apoptosis signals. Moreover, curcumol inhibited colorectal cancer in xenograft models of nude mice. Immunohistochemical and Western blot analysis revealed that curcumol could decrease the expression of ki-67, Bcl-2 as well as CREB1, and increase the expression of Bax and the phosphorylation of p38, which were consistent with our in vitro study. Overall, our in vitro and in vivo data confirmed the anti-cancer activity of curcumol, which was related to a significant inhibition of IGF-1R and activation of p38 MAPKs, indicating that curcumol may be a potential anti-tumor agent for colorectal carcinoma therapy. PMID:26307972

  17. Curcumol Inhibits Growth and Induces Apoptosis of Colorectal Cancer LoVo Cell Line via IGF-1R and p38 MAPK Pathway.

    PubMed

    Wang, Juan; Huang, Fengxiang; Bai, Zhun; Chi, Bixia; Wu, Jiacai; Chen, Xu

    2015-08-20

    Curcumol, isolated from the traditional medical plant Rhizoma Curcumae, is the bioactive component of Zedoary oil, whose potential anti-tumor effect has attracted considerable attention in recent years. Though many researchers have reported curcumol and its bioactivity, the potential molecular mechanism for its anti-cancer effect in colorectal cancer LoVo cells still remains unclear. In the present study, we found that curcumol showed growth inhibition and induced apoptosis of LoVo cells in a dose- and time-dependent manner. The occurrence of its proliferation inhibition and apoptosis came with suppression of IGF-1R expression, and then increased the phosphorylation of p38 mitogen activated protein kinase (MAPK), which might result in a cascade response by inhibiting the CREB survival pathway and finally triggered Bax/Bcl-2 and poly(ADP-ribose) polymerase 1 (PARP-1) apoptosis signals. Moreover, curcumol inhibited colorectal cancer in xenograft models of nude mice. Immunohistochemical and Western blot analysis revealed that curcumol could decrease the expression of ki-67, Bcl-2 as well as CREB1, and increase the expression of Bax and the phosphorylation of p38, which were consistent with our in vitro study. Overall, our in vitro and in vivo data confirmed the anti-cancer activity of curcumol, which was related to a significant inhibition of IGF-1R and activation of p38 MAPKs, indicating that curcumol may be a potential anti-tumor agent for colorectal carcinoma therapy.

  18. 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.

  19. BX-795 inhibits HSV-1 and HSV-2 replication in a JNK/p38-dependent manner without interfering with PDK1 activity.

    PubMed

    Su, Ai-Rong; Qiu, Min; Li, Yan-Lei; Xu, Wen-Tao; Song, Si-Wei; Wang, Xiao-Hui; Song, Hong-Yong; Zheng, Nan; Wu, Zhi-Wei

    2017-01-23

    BX-795, an aminopyrimidine compound, was developed as an inhibitor of 3-phosphoinositide-dependent kinase 1 (PDK1) and was later shown to be a potent inhibitor of the IKK-related kinase, TANK-binding kinase 1 (TBK1) and IKKɛ. The currect study aimed to investigate the inhibition mechanism(s) of BX-795 on Herpes simplex virus (HSV) replication. HEC-1-A or Vero cells were treated in the absence or presence of serial concentrations of BX-795 and infected with HSV-1 or HSV-2 for different periods. BX-795 did not suppress HSV IE gene transcription at 6 h postinfection. In contrast, at 12 h postinfection, BX-795 exhibited an inhibitory effect on the expression of not only the two IE genes (ICP0 and ICP27) but also on the late gene (gD) in a dose-dependent manner with low cytotoxicity. HSV-2 infection resulted in the activation of PI3K and Akt. BX-795 inhibited HSV-2-induced Akt phosphorylation and activation. The blockage of PI3K/Akt/mTOR by LY294002 and rapamycin did not affect HSV-2 replication. HSV-2 infection increased the phosphorylation of JNK and p38 but reduced ERK phosphorylation at 8 h postinfection in HEC-1A cells. SB203580 (p38 inhibitor) and SP600125 (JNK inhibitor), but not PD98059 (ERK inhibitor), inhibited viral replication in both HEC-1-A and Vero cells in a dose-dependent manner. BX-795 inhibited HSV-2-induced activation of JNK and p38 MAP kinase. Furthermore, BX-795 inhibited activation of c-Jun and ATF-2 caused by HSV-2 infection. BX-795 blocked PMA-stimulated c-Jun activation as well as HSV-2-mediated c-Jun nuclear translocation. BX-795 also inhibited AP-1 activation induced by HSV-2, PMA, TNF-α in a dose-dependent manner. The inhibitory effect of BX-795 on HSV replication was attenuated by overexpression of p38/JNK. BX-795 completely blocked HSV-2-induced MKK4 phosphorylation suggesting that BX-795 acted upstream of JNK and p38 MAP kinase. BX-795 had no effects on HSV-induced NF-κB activation. The results indicated that BX-795 inhibited HSV

  20. 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.

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

    PubMed

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

    2013-03-27

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

  2. 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

  3. LPS-induced production of TNF-α and IL-6 in mast cells is dependent on p38 but independent of TTP.

    PubMed

    Hochdörfer, Thomas; Tiedje, Christopher; Stumpo, Deborah J; Blackshear, Perry J; Gaestel, Matthias; Huber, Michael

    2013-06-01

    The production of the proinflammatory cytokines TNF-α and IL-6 is regulated by various mRNA-binding proteins, influencing stability and translation of the respective transcripts. Research in macrophages has shown the importance of the p38-MK2-tristetraprolin (TTP) axis for regulation of TNF-α mRNA stability and translation. In the current study we examined a possible involvement of p38 and TTP in LPS-induced cytokine production in bone marrow-derived mast cells (BMMCs). Using pharmacological inhibitors we initially found a strong dependence of LPS-induced TNF-α and IL-6 production on p38 activation, whereas activation of the Erk pathway appeared dispensable. LPS treatment also induced p38-dependent expression of the TTP gene. This prompted us to analyze the proinflammatory cytokine response in BMMCs generated from TTP-deficient mice. Unexpectedly, there were no significant differences in cytokine production between TTP-deficient and WT BMMCs in response to LPS. Gene expression and cytokine production of TNF-α and IL-6 as well as stability of the TNF-α transcript were comparable between TTP-deficient and WT BMMCs. In contrast to TTP mRNA expression, TTP protein expression could not be detected in BMMCs. While we successfully precipitated and detected TTP from lysates of LPS-stimulated RAW 264.7 macrophages, this was not accomplished from BMMC lysates. In contrast, we found mRNA and protein expressions of the other TIS11 family members connected to regulation of mRNA stability, BRF1 and BRF2, and detected their interaction with 14-3-3 proteins. These data suggest that control of cytokine mRNA stability and translation in MCs is exerted by proteins different from TTP.

  4. Galangin induces B16F10 melanoma cell apoptosis via mitochondrial pathway and sustained activation of p38 MAPK.

    PubMed

    Zhang, Wenjing; Lan, Yan; Huang, Qilai; Hua, Zichun

    2013-05-01

    Galangin, an active flavonoid present at high concentration in Alpinia officinarum Hance and propolis, shows cytotoxicity towards several cancer cell lines, including melanoma. However, the specific cellular targets of galangin-induced cytotoxicity in melanoma are still unknown. Here, we investigated the effects of galangin in B16F10 melanoma cells and explored the possible molecular mechanisms. Galangin significantly decreased cell viability of B16F10 cells, and also induced cell apoptosis shown by Hoechst 33342 staining and Annexin V-PI double staining flow cytometric assay. Furthermore, upon galangin treatment, disruption of mitochondrial membrane potential was observed by JC-1 staining. Western blotting analysis indicated that galangin activated apoptosis signaling cascades by cleavage of procaspase-9, procaspase-3 and PARP in B16F10 cells. Moreover, galangin significantly induced activation of phosphor-p38 MAPK in a time and dose dependent manner. SB203580, an inhibitor of p38, partially attenuated galangin-induced apoptosis in B16F10 cells. Taken together, this work suggests that galangin has the potential to be a promising agent for melanoma treatment and may be further evaluated as a chemotherapeutic agent.

  5. 2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced MUC5AC expression: aryl hydrocarbon receptor-independent/EGFR/ERK/p38-dependent SP1-based transcription.

    PubMed

    Lee, Yong C; Oslund, Karen L; Thai, Philip; Velichko, Sharlene; Fujisawa, Tomoyuki; Duong, Trang; Denison, Michael S; Wu, Reen

    2011-08-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent environmental toxicant. Epidemiological studies have associated TCDD exposure with the development of chronic obstructive pulmonary disease, which is manifested by mucous/goblet cell hyperplasia. The purpose of this research was to elucidate the pathway/mechanisms that lead to TCDD-induced gene expression in both primary normal human bronchial epithelial cells and an immortalized cell line, HBE1, under air-liquid interface conditions. TCDD exposure induced a time-dependent elevation of MUC5AC mRNA and protein synthesis, and cytochrome p450 1A1 (CYP1A1) expression in these cells. Treatment with an aryl hydrocarbon receptor antagonist had no effect on TCDD-induced MUC5AC expression, but significantly suppressed CYP1A1 induction. However, treatments with inhibitors of signaling pathways and the expression of dominant negative mutants of epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK) and p38, but not the inhibition of c-Jun N-terminal kinase pathway, abrogated MUC5AC induction, but not that of CYP1A1. These effects also occurred at the MUC5AC promoter-reporter level using the chimeric construct for a transient transfection study. Western blot analysis confirmed the phosphorylation of activated EGFR, ERK, and p38 signaling molecules, but not the c-Jun N-terminal kinase, in cells after TCDD exposure. Specificity protein 1 (Sp1) phosphorylation also occurred in cells after TCDD exposure. Both MUC5AC expression and the promoter activity were inhibited by mithramycin A, an inhibitor specific to Sp1-based transcription. These results lead to the conclusion that TCDD induced MUC5AC expression through a noncanonical aryl hydrocarbon receptor-independent, EGFR/ERK/p38-mediated signaling pathway-mediated/Sp1-based transcriptional mechanism.

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

    SciTech Connect

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

    2007-08-17

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

  7. P38 and JNK signal pathways are involved in the regulation of phlorizin against UVB-induced skin damage.

    PubMed

    Zhai, Yimiao; Dang, Yongyan; Gao, Wenke; Zhang, Ye; Xu, Peng; Gu, Jun; Ye, Xiyun

    2015-04-01

    Phlorizin is well known to inhibit sodium/glucose cotransporters in the kidney and intestine for the treatment of diabetes, obesity and stress hyperglycaemia. However, the effects of phlorizin against ultraviolet B (UVB) irradiation and its molecular mechanism are still unknown. We examined the effects of phlorizin on skin keratinocyte apoptosis, reactive oxygen species (ROS) production, pro-inflammatory responses after UVB irradiation and the changes of some signal molecules by in vitro and in vivo assay. We observed that phlorizin pretreatments inhibited HaCaT cell apoptosis and overproduction of ROS induced by UVB. Phlorizin also decreased the expression of UVB-induced pro-inflammatory cytokines, such as interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and interleukin-8 (IL-8) at the mRNA level. Topical application of phlorizin on UVB-exposed skin of nude mice prevented the formation of scaly skin and erythema, inhibited the increase of epidermal thickness and reduced acute inflammation infiltration in skin. Additionally, PCR, Western blot and immunohistochemical data showed that phlorizin reversed the overexpression of cyclooxygenase-2 (Cox-2) induced by UVB irradiation both in vitro and in vivo. The activation of p38 and JNK mitogen-activated protein kinases (MAPK) after UVB irradiation was also inhibited by phlorizin. These findings suggest that phlorizin is effective in protecting skin against UVB-induced skin damage by decreasing ROS overproduction, Cox-2 expression and the subsequent excessive inflammation reactions. It seemed that p38 and JNK MAPK signal pathways are involved in the regulation of the protective function of phlorizin.

  8. UV-B radiation-induced oxidative stress and p38 signaling pathway involvement in the benthic copepod Tigriopus japonicus.

    PubMed

    Kim, Bo-Mi; Rhee, Jae-Sung; Lee, Kyun-Woo; Kim, Min-Jung; Shin, Kyung-Hoon; Lee, Su-Jae; Lee, Young-Mi; Lee, Jae-Seong

    2015-01-01

    Ultraviolet B (UV-B) radiation presents an environmental hazard to aquatic organisms. To understand the molecular responses of the intertidal copepod Tigriopus japonicus to UV-B radiation, we measured the acute toxicity response to 96 h of UV-B radiation, and we also assessed the intracellular reactive oxygen species (ROS) levels, glutathione (GSH) content, and antioxidant enzyme (GST, GR, GPx, and SOD) activities after 24 h of exposure to UV-B with LD50 and half LD50 values. Also, expression patterns of p53 and hsp gene families with phosphorylation of p38 MAPK were investigated in UV-B-exposed copepods. We found that the ROS level, GSH content, and antioxidant enzyme activity levels were increased with the transcriptional upregulation of antioxidant-related genes, indicating that UV-B induces oxidative stress by generating ROS and stimulating antioxidant enzymatic activity as a defense mechanism. Additionally, we found that p53 expression was significantly increased after UV-B irradiation due to increases in the phosphorylation of the stress-responsive p38 MAPK, indicating that UV-B may be responsible for inducing DNA damage in T. japonicus. Of the hsp family genes, transcriptional levels of hsp20, hsp20.7, hsp70, and hsp90 were elevated in response to a low dose of UV-B radiation (9 kJ m(-2)), suggesting that these hsp genes may be involved in cellular protection against UV-B radiation. In this paper, we performed a pathway-oriented mechanistic analysis in response to UV-B radiation, and this analysis provides a better understanding of the effects of UV-B in the intertidal benthic copepod T. japonicus.

  9. Dihydroartemisinin inhibits vascular endothelial growth factor-induced endothelial cell migration by a p38 mitogen-activated protein kinase-independent pathway.

    PubMed

    Guo, Ling; Dong, Fengyun; Hou, Yinglong; Cai, Weidong; Zhou, Xia; Huang, Ai-Ling; Yang, Min; Allen, Thaddeus D; Liu, Ju

    2014-12-01

    Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has been demonstrated to possess a strong antiangiogenic activity. However, the molecular mechanisms underlying this effect remain unclear. Endothelial cell (EC) migration is an essential component of angiogenesis, and the p38 mitogen-activated protein kinase (MAPK) signaling pathway plays a key role in the regulation of migration induced by vascular endothelial growth factor (VEGF). The aim of the present study was to investigate the effects of DHA on EC migration and the p38 MAPK signaling pathway. Human umbilical vein ECs (HUVECs) were treated with DHA and VEGF-induced migration was analyzed. The activation of p38 MAPK was detected by western blot analysis, and the migration assays were performed with a p38-specific inhibitor, SB203850. It was revealed that 20 μM DHA significantly reduced EC migration in the transwell migration assay, wound healing assay and electrical cell-substrate impedance sensing real-time analysis. However, DHA did not affect p38 MAPK phosphorylation or expression. In the absence or presence of SB203850, DHA induced a similar proportional reduction of EC migration in the three migration assays. Therefore, the present study demonstrated that DHA inhibits VEGF-induced EC migration via a p38 MAPK-independent pathway.

  10. Interferon regulatory factor-1 activates autophagy to aggravate hepatic ischemia-reperfusion injury via the P38/P62 pathway in mice

    PubMed Central

    Yu, Yao; Li, Shipeng; Wang, Zhen; He, Jindan; Ding, Yijie; Zhang, Haiming; Yu, Wenli; Shi, Yiwei; Cui, Zilin; Wang, Ximo; Wang, Zhiliang; Sun, Liying; Zhang, Rongxin; Du, Hongyin; Zhu, Zhijun

    2017-01-01

    Increasing evidence has linked autophagy to a detrimental role in hepatic ischemia- reperfusion (IR) injury (IRI). Here we focus on the role of interferon regulatory factor-1 (IRF-1) in regulating autophagy to aggravate hepatic IRI. We found that IRF-1 was up-regulated during hepatic IRI and was associated with an activation of the autophagic signaling. This increased IRF-1 expression, which was allied with high autophagic activity, amplified liver damage to IR, an effect which was abrogated by IRF-1 depletion. Moreover, IRF-1 contributed to P38 induced autophagic and apoptotic cell death, that can play a key role in liver dysfunction. The levels of P62 mRNA and protein were increased when P38 was activated and decreased when P38 was inhibited by SB203580. We conclude that IRF-1 functioned as a trigger to activate autophagy via P38 activation and that P62 was required for this P38-mediated autophagy. IRF-1 appears to exert a pivotal role in hepatic IRI, by predisposing hepatocytes to activate an autophagic pathway. Such an effect promotes autophagic cell death through the P38/P62 pathway. The identification of this novel pathway, that links expression levels of IRF-1 with autophagy, may provide new insights for the generation of novel protective therapies directed against hepatic IRI. PMID:28266555

  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

    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.

  12. 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

  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.

  14. Graphene/single-walled carbon nanotube hybrids promoting osteogenic differentiation of mesenchymal stem cells by activating p38 signaling pathway

    PubMed Central

    Yan, Xinxin; Yang, Wen; Shao, Zengwu; Yang, Shuhua; Liu, Xianzhe

    2016-01-01

    Carbon nanomaterials are becoming increasingly significant in biomedical fields since they exhibit exceptional physicochemical and biocompatible properties. Today, the stem cells offer potentially new therapeutic approaches in tissue engineering and regenerative medicine. However, the induction of differentiation into specific lineages remains challenging, which provoked us to explore the biomedical applications of carbon nanomaterials in stem cells. In this study, we investigated the interactions between graphene/single-walled carbon nanotube (G/SWCNT) hybrids and rat mesenchymal stem cells (rMSCs) and focused on the proliferation and differentiation of rMSCs treated with G/SWCNT hybrids. Cell viability and morphology were evaluated using cell counting kit-8 assay and immunofluorescence staining, respectively. Osteogenic differentiation evaluated by alkaline phosphatase activity of MSCs proved to be higher after treatment with G/SWCNT hybrids, and the mineralized matrix nodule formation was also enhanced. In addition, the expression levels of osteogenic-associated genes were upregulated, while the adipocyte-specific markers were downregulated. Consistent with these results, we illustrated that the effect of G/SWCNT hybrids on the process of osteogenic differentiation of rMSCs can be modulated by activating the p38 signaling pathway and inhibiting the extracellular signal-regulated kinase 1/2 pathway. Nevertheless, our study suggests that carbon nanomaterials offer a promising platform for regenerative medicine in the near future. PMID:27799770

  15. Effect of Hibiscus anthocyanins-rich extract induces apoptosis of proliferating smooth muscle cell via activation of P38 MAPK and p53 pathway.

    PubMed

    Lo, Chia-Wen; Huang, Hui-Pei; Lin, Hui-Mei; Chien, Cheng-Ting; Wang, Chau-Jong

    2007-12-01

    Hibiscus sabdariffa L. (Malvaceae), an attractive plant believed to be native to Africa, is cultivated in Sudan and in eastern Taiwan. It has been reported to contain a number of protocatechuic acid and anthocyanins. In vitro experimental studies have shown that anthocyanins administration of the extract produces anti-inflammation and chemoprevention effects. In spite of the wide use of Hibiscus sabdariffa L. in folk medicine for treating various diseases, our previous study indicated a potency of Hibiscus sabdariffa extract (HSE) in anti-atherosclerosis. The mechanisms of anthocyanins administration of the extract produce from Hibiscus sabdariffa L. to attenuate atherosclerosis were not clarified. In this study, we found that Hibiscus anthocyanins (HAs) could inhibit the serum-stimulated proliferation of smooth muscle cell (SMC) and result in cell apoptosis. The HAs inducing cell apoptosis was dose dependent. We further used SB203580 (p38 inhibitor) to block cellular apoptosis and evaluate its effect on the HAs-inducing SMC death via some apoptosis criteria including DNA fragmentation and flow cytometry. We suggested that the mechanisms of the inhibitory effect of HAs on atherosclerosis could be via inhibiting the proliferation of SMC. HAs induces apoptosis via (i) activating p38 MAP kinase that subsequently phosphorylates target protein c-Jun and transduces the signal to further activate the apoptotic protein cascades that contain Fas-mediated signaling (Fas/caspase-8 signaling module) and (ii) activating p53 and inducing bax expression. As an outcome of the events, cytochrome c releases from the mitochondria, leading to cell apoptosis. In these experiments, HAs showed strong potential to induce SMC cell apoptosis via p38 and p53 pathway. In consequence, the rate of atherosclerotic formation is slowed down, and the progress is suppressed.

  16. 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

  17. Alisertib induces G2/M arrest, apoptosis, and autophagy via PI3K/Akt/mTOR- and p38 MAPK-mediated pathways in human glioblastoma cells

    PubMed Central

    Liu, Zheng; Wang, Feng; Zhou, Zhi-Wei; Xia, He-Chun; Wang, Xin-Yu; Yang, Yin-Xue; He, Zhi-Xu; Sun, Tao; Zhou, Shu-Feng

    2017-01-01

    Glioblastoma (GBM) is the most common brain tumor with poor response to current therapeutics. Alisertib (ALS), a second-generation selective Aurora kinase A (AURKA) inhibitor, has shown potent anticancer effects on solid tumors in animal studies. This study aimed to investigate the killing effect of ALS on GBM cell line DAOY and the possible underlying mechanisms using both bioinformatic and cell-based approaches. Our molecular docking showed that ALS preferentially bound AURKA over AURKB via hydrogen bond formation, charge interaction, and π-π stacking. ALS also bound key regulating proteins of cell cycle, apoptosis and autophagy, such as cyclin-dependent kinase 1 (CDK1/CDC2), CDK2, cyclin B1, p27 Kip1, p53, cytochrome C, cleaved caspase 3, Bax, Bcl-2, Bcl-xl, phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR), 5’-adenosine monophosphate-activated protein kinase (AMPK), p38 mitogen-activated protein kinase (MAPK), beclin 1, phosphatase and tensin homolog (PTEN), and microtubule-associated protein light chain 3 (LC3). ALS exhibited potent growth-inhibitory, pro-apoptotic, and pro-autophagic effects on DAOY cells in a concentration-dependent manner. Notably, ALS remarkably induced G2/M arrest mainlyvia regulating the expression of CDK1/CDC2, CDK2, cyclin B1, p27 Kip1, and p53 in DAOY cells. ALS significantly induced the expression of mitochondria-mediated pro-apoptotic proteins such as Baxbut inhibited the expression of anti-apoptotic proteins such as Bcl-2 and Bcl-xl, with a significant increase in the release of cytochrome C and the activation of caspases 3 and 9. ALS also induced PI3K/Akt/mTOR and p38 MAPK signaling pathways while activating the AMPK signaling pathway. Taken together, these findings indicate that ALS exerts a potent inhibitory effect on cell proliferation and induces mitochondria-dependent apoptosis and autophagy with the involvement of PI3K/Akt/mTOR- and p38 MAPK-mediated signaling pathways in

  18. Human S100A7 Induces Mature Interleukin1α Expression by RAGE-p38 MAPK-Calpain1 Pathway in Psoriasis

    PubMed Central

    Lei, Hu; Li, Xiangyun; Jing, Bo; Xu, Hanzhang; Wu, Yingli

    2017-01-01

    Psoriatic keratinocytes express exaggerated levels of inflammatory cytokines, and show aberrant hyperproliferation and terminal differentiation in the pathogenesis of psoriasis. The antimicrobial protein hS100A7 (psoriasin) has been found highly expressed in psoriatic skin, but the mechanism and physiological function remain largely unknown. We observed that hS100A7 induces mature interleukin 1α (17kDa) expression in normal human epidermal keratinocytes, which is dependent on RAGE-p38 MAPK and calpain-1 as the inhibitors or knockdown of them completely decreased the expression of mature interleukin1α. Then, we proved mS100a7a15, mature IL-1α and calpain-1 were highly expressed in imquimod-induced psoriasis model and mouse IL-17a-neutralizing antibody treatment attenuated mS100a7a15 expression. At last, PD 151746 (calpain-1 inhibitor) treatment decreased epidermal thickness in imquimod-induced psoriasis model. Taken together, our results suggest that mature IL-1α induced by hS100A7 is via RAGE-p38 MAPK and calpain-1 pathway in keratinocyte and this mechanism may play an important role during psoriasis. PMID:28060905

  19. 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

  20. CoCl2 induces protective events via the p38-MAPK signalling pathway and ANP in the perfused amphibian heart.

    PubMed

    Gaitanaki, Catherine; Kalpachidou, Theodora; Aggeli, Ioanna-Katerina S; Papazafiri, Panagiota; Beis, Isidoros

    2007-07-01

    Mitogen-activated protein kinases (MAPKs) constitute one of the most important intracellular signalling pathways. In particular, the p38-MAPK subfamily is known to be activated under various stressful conditions, such as mechanical or oxidative stress. Furthermore, cobalt chloride (CoCl2) has been shown to mimic hypoxic responses in various cell lines and cause overproduction of reactive oxygen species (ROS). In the current study, we investigated the effect of CoCl2 on p38-MAPK signalling pathway in the perfused Rana ridibunda heart. Immunoblot analysis of the phosphorylated, and thus activated, form of p38-MAPK revealed that maximum phosphorylation was attained at 500 micromol l(-1) CoCl2. A similar profile was observed for MAPKAPK2 and Hsp27 phosphorylation (direct and indirect p38-MAPK substrates, respectively). Time course analysis of p38-MAPK phosphorylation pattern showed that the kinase reached its peak within 15 min of treatment with 500 micromol l(-1) CoCl2. Similar results were obtained for Hsp27 phosphorylation. In the presence of the antioxidants Trolox or Lipoic acid, p38-MAPK CoCl2-induced phosphorylation was attenuated. Analogous results were obtained for Hsp27 and MAPKAPK2. In parallel, mRNA levels of the ANP gene, a hormone whose transcriptional regulation has previously been shown to be regulated by p38-MAPK, were examined (semi-quantitative ratiometric RT-PCR). CoCl2 treatment significantly increased ANP mRNA levels, whereas, in the presence of antioxidants, the transcript levels returned to basal values. All the above data indicate that CoCl2 stimulates compensatory mechanisms involving the p38-MAPK signalling cascade along with ANP.

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

    PubMed

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

    2008-03-01

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

  2. The CXCL10/CXCR3 axis promotes cardiac microvascular endothelial cell migration via the p38/FAK pathway in a proliferation-independent manner.

    PubMed

    Xia, Jing-Bo; Mao, Cheng-Zhou; Chen, Zhuo-Ying; Liu, Guang-Hui; Wu, Hai-Yan; Zhou, Deng-Cheng; Park, Kyu-Sang; Zhao, Hui; Kim, Soo-Ki; Cai, Dong-Qing; Qi, Xu-Feng

    2016-04-01

    CXCL10 is a chemokine with potent chemotactic activity for immune and non-immune cells expressing its receptor CXCR3. Previous studies have demonstrated that CXCL10 is involved in myocardial infarction. However, the role of CXCL10 in cardiac microvascular endothelial cell (CMEC) regulation and related mechanisms remains unclear. In this study, we investigated the effects of CXCL10 on the CMEC migration and explored its potential molecular mechanism by wound healing, cell proliferation and viability analysis. Furthermore, migration-related signaling pathways, including FAK, Erk, p38 and Smad, were examined by Western blotting. We found that CXCL10 significantly promotes CMEC migration under normal conditions and during hypoxia/ischemia. However, no significant differences in CMEC proliferation and viability were observed with or without CXCL10 treatment. CXCL10-mediated CMEC migration was greatly blocked by treatment with an anti-CXCR3 antibody. Although CXCL10 treatment promoted phosphorylation and activation of the FAK, Erk, and p38 pathways during hypoxia/ischemia, CXCL10-mediated CMEC migration was significantly blocked by p38 and FAK inhibitors, but not by an Erk inhibitor. Furthermore, CXCL10-mediated FAK activation was suppressed by the p38 inhibitor. These findings indicated that the CXCL10/CXCR3 pathway promotes the migration of CMECs under normal conditions and during hypoxia/ischemia in a proliferation-independent manner, at least in part, through regulation of the p38/FAK pathways.

  3. Icariin inhibits TNF-α/IFN-γ induced inflammatory response via inhibition of the substance P and p38-MAPK signaling pathway in human keratinocytes.

    PubMed

    Kong, Lingwen; Liu, Jiaqi; Wang, Jia; Luo, Qingli; Zhang, Hongying; Liu, Baojun; Xu, Fei; Pang, Qi; Liu, Yingchao; Dong, Jingcheng

    2015-12-01

    Pro-inflammatory cytokines play a crucial role in the etiology of atopic dermatitis. We demonstrated that Herba Epimedii has anti-inflammatory potential in an atopic dermatitis mouse model; however, limited research has been conducted on the anti-inflammatory effects and mechanism of icariin, the major active ingredient in Herba Epimedii, in human keratinocytes. In this study, we evaluated the anti-inflammatory potential and mechanisms of icariin in the tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-induced inflammatory response in human keratinocytes (HaCaT cells) by observing these cells in the presence or absence of icariin. We measured IL-6, IL-8, IL-1β, MCP-1 and GRO-α production by ELISA; IL-6, IL-8, IL-1β, intercellular adhesion molecule-1 (ICAM-1) and tachykinin receptor 1 (TACR1) mRNA expression by real-time PCR; and P38-MAPK, P-ERK and P-JNK signaling expression by western blot in TNF-α/IFN-γ-stimulated HaCaT cells before and after icariin treatment. The expression of TNF-α-R1 and IFN-γ-R1 during the stimulation of the cell models was also evaluated before and after icariin treatment. We investigated the effect of icariin on these pro-inflammatory cytokines and detected whether this effect occurred via the mitogen-activated protein kinase (MAPK) signal transduction pathways. We further specifically inhibited the activity of two kinases with 20μM SB203580 (a p38 kinase inhibitor) and 50μM PD98059 (an ERK1/2 kinase inhibitor) to determine the roles of the two signal pathways involved in the inflammatory response. We found that icariin inhibited TNF-α/IFN-γ-induced IL-6, IL-8, IL-1β, and MCP-1 production in a dose-dependent manner; meanwhile, the icariin treatment inhibited the gene expression of IL-8, IL-1β, ICAM-1 and TACR1 in HaCaT cells in a time- and dose-dependent manner. Icariin treatment resulted in a reduced expression of p-P38 and p-ERK signal activation induced by TNF-α/IFN-γ; however, only SB203580, the p38 alpha

  4. The p38/MK2-Driven Exchange between Tristetraprolin and HuR Regulates AU–Rich Element–Dependent Translation

    PubMed Central

    Tiedje, Christopher; Ronkina, Natalia; Tehrani, Mohammad; Dhamija, Sonam; Laass, Kathrin; Holtmann, Helmut; Kotlyarov, Alexey; Gaestel, Matthias

    2012-01-01

    TNF expression of macrophages is under stringent translational control that depends on the p38 MAPK/MK2 pathway and the AU–rich element (ARE) in the TNF mRNA. Here, we elucidate the molecular mechanism of phosphorylation-regulated translation of TNF. We demonstrate that translation of the TNF-precursor at the ER requires expression of the ARE–binding and -stabilizing factor human antigen R (HuR) together with either activity of the p38 MAPK/MK2 pathway or the absence of the ARE-binding and -destabilizing factor tristetraprolin (TTP). We show that phosphorylation of TTP by MK2 decreases its affinity to the ARE, inhibits its ability to replace HuR, and permits HuR-mediated initiation of translation of TNF mRNA. Since translation of TTP's own mRNA is also regulated by this mechanism, an intrinsic feedback control of the inflammatory response is ensured. The phosphorylation-regulated TTP/HuR exchange at target mRNAs provides a reversible switch between unstable/non-translatable and stable/efficiently translated mRNAs. PMID:23028373

  5. N-WASP promotes invasion and migration of cervical cancer cells through regulating p38 MAPKs signaling pathway.

    PubMed

    Hou, Jinxuan; Yang, Hui; Huang, Xin; Leng, Xiaohua; Zhou, Fuxiang; Xie, Conghua; Zhou, Yunfeng; Xu, Yu

    2017-01-01

    Neural Wiskott-Aldrich syndrome protein (N-WASP) is an important member of the WASP family involved in the actin cytoskeleton reorganization. Recent evidence suggests that N-WASP may play important roles in tumor progression and metastasis. However, the contribution of N-WASP to cervical cancer is still unknown. The present study focused on elucidating the role of N-WASP in the malignant behavior of cervical cancer cells. We found that N-WASP overexpressed in cervical cancer tissues compared with paired paracancerous tissues and normal tissues, and similar results were observed in several cervical cancer cell lines. Furthermore, we demonstrated that overexpression of N-WASP facilitated migration and invasion of cervical cancer cells, while downregulation of N-WASP resulted in decreased cell migration and invasion. In addition, the data showed that N-WASP might promote invasion and migration of cervical cancer cells via regulating the activity of p38 MAPKs pathway. Altogether, the study suggested that N-WASP might serve as an oncogene in cervical cancer, and provided novel insights into the mechanism that how N-WASP promoted invasion and migration of cervical cancer cells.

  6. N-WASP promotes invasion and migration of cervical cancer cells through regulating p38 MAPKs signaling pathway

    PubMed Central

    Hou, Jinxuan; Yang, Hui; Huang, Xin; Leng, Xiaohua; Zhou, Fuxiang; Xie, Conghua; Zhou, Yunfeng; Xu, Yu

    2017-01-01

    Neural Wiskott-Aldrich syndrome protein (N-WASP) is an important member of the WASP family involved in the actin cytoskeleton reorganization. Recent evidence suggests that N-WASP may play important roles in tumor progression and metastasis. However, the contribution of N-WASP to cervical cancer is still unknown. The present study focused on elucidating the role of N-WASP in the malignant behavior of cervical cancer cells. We found that N-WASP overexpressed in cervical cancer tissues compared with paired paracancerous tissues and normal tissues, and similar results were observed in several cervical cancer cell lines. Furthermore, we demonstrated that overexpression of N-WASP facilitated migration and invasion of cervical cancer cells, while downregulation of N-WASP resulted in decreased cell migration and invasion. In addition, the data showed that N-WASP might promote invasion and migration of cervical cancer cells via regulating the activity of p38 MAPKs pathway. Altogether, the study suggested that N-WASP might serve as an oncogene in cervical cancer, and provided novel insights into the mechanism that how N-WASP promoted invasion and migration of cervical cancer cells. PMID:28337270

  7. 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.

  8. Epithelial control of gut-associated lymphoid tissue formation through p38α-dependent restraint of NF-κB signaling

    PubMed Central

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

    2015-01-01

    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. Here we show that p38α regulates gut-associated lymphoid tissue (GALT) formation in a non-cell-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 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

  9. Hypoxia induces discoidin domain receptor-2 expression via the p38 pathway in vascular smooth muscle cells to increase their migration.

    PubMed

    Chen, Shih-Chung; Wang, Bao-Wei; Wang, Danny Ling; Shyu, Kou-Gi

    2008-10-03

    Discoidin domain receptor-2 (DDR2) is a receptor tyrosine kinase that binds to the extracellular matrix. We investigated the role of hypoxia in DDR2 expression in vascular smooth muscle cells (VSMCs) and the underlying mechanism. Subjecting VSMCs to hypoxia (2.5% O(2)) induced DDR2 expression; treatments with a specific inhibitor (SB203580) of p38 mitogen-activated protein kinase (MAPK) or p38-specific small interference RNA (siRNA) abolished this hypoxia-induced DDR2 expression. Gel shifting assays showed that hypoxia increased the Myc-Max-DNA binding activity in the promoter region of DDR2; inhibition of p38 MAPK activation by SB203580 and p38-specific siRNA blocked hypoxia-induced DDR2 promoter activity. Hypoxia also induced matrix metalloproteinase-2 (MMP-2) activity in VSMCs and increased their migration. These VSMC responses to hypoxia were inhibited by DDR2- and p38-specific siRNAs. Our results suggested that hypoxia induces DDR2 expression in VSMCs at the transcriptional level, which is mediated by the p38 MAPK pathway and contributes to VSMC migration.

  10. 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.

  11. Protein kinase C promotes apoptosis in LNCaP prostate cancer cells through activation of p38 MAPK and inhibition of the Akt survival pathway.

    PubMed

    Tanaka, Yuichi; Gavrielides, M Veronica; Mitsuuchi, Yasuhiro; Fujii, Teruhiko; Kazanietz, Marcelo G

    2003-09-05

    Activation of protein kinase C (PKC) by phorbol esters or diacylglycerol mimetics induces apoptosis in androgen-dependent prostate cancer cells, an effect that involves both the activation of the classic PKC alpha and the novel PKC delta isozymes (Fujii, T., García-Bermejo, M. L., Bernabó, J. L., Caamaño, J., Ohba, M., Kuroki, T., Li, L., Yuspa, S. H., and Kazanietz, M. G. (2000) J. Biol. Chem. 275, 7574-7582 and Garcia-Bermejo, M. L., Leskow, F. C., Fujii, T., Wang, Q., Blumberg, P. M., Ohba, M., Kuroki, T., Han, K. C., Lee, J., Marquez, V. E., and Kazanietz, M. G. (2002) J. Biol. Chem. 277, 645-655). In the present study we explored the signaling events involved in this PKC-mediated effect, using the androgen-dependent LNCaP cell line as a model. Stimulation of PKC by phorbol 12-myristate 13-acetate (PMA) leads to the activation of ERK1/2, p38 MAPK, and JNK in LNCaP cells. Here we present evidence that p38 MAPK, but not JNK, mediates PKC-induced apoptosis. Because LNCaP cells have hyperactivated Akt function due to PTEN inactivation, we examined whether this survival pathway could be affected by PKC activation. Interestingly, activation of PKC leads to a rapid and reversible dephosphorylation of Akt, an effect that was prevented by the pan-PKC inhibitor GF109302X and the cPKC inhibitor Gö6976. In addition, the diacylglycerol mimetic agent HK654, which selectively stimulates PKC alpha in LNCaP cells, also induced the dephosphorylation of Akt in LNCaP cells. Inactivation of Akt function by PKC does not involve the inhibition of PI3K, and it is prevented by okadaic acid, suggesting the involvement of a phosphatase 2A in PMA-induced Akt dephosphorylation. Finally, we show that, when an activated form of Akt is delivered into LNCaP cells by either transient transfection or adenoviral infection, the apoptotic effect of PMA is significantly reduced. Our results highlight a complex array of signaling pathways regulated by PKC isozymes in LNCaP prostate cancer cells

  12. Polydatin ameliorates Staphylococcus aureus-induced mastitis in mice via inhibiting TLR2-mediated activation of the p38 MAPK/NF-κB pathway

    PubMed Central

    Jiang, Kang-feng; Zhao, Gan; Deng, Gan-zhen; Wu, Hai-chong; Yin, Nan-nan; Chen, Xiu-ying; Qiu, Chang-wei; Peng, Xiu-li

    2017-01-01

    Recent studies show that Polydatin (PD) extracted from the roots of Polygonum cuspidatum Sieb, a widely used traditional Chinese remedies, possesses anti-inflammatory activity in several experimental models. In this study, we investigated the anti-inflammatory effects of PD on Staphylococcus aureus-induced mastitis in mice and elucidated the potential mechanisms. In mice with S aureus-induced mastitis, administration of PD (15, 30, 45 mg/kg, ip) or dexamethasone (Dex, 5 mg/kg, ip) significantly suppressed the infiltration of inflammatory cells, ameliorated the mammary structural damage, and inhibited the activity of myeloperoxidase, a biomarker of neutrophils accumulation. Furthermore, PD treatment dose-dependently decreased the levels of TNF-α, IL-1β, IL-6 and IL-8 in the mammary gland tissues. PD treatment also dose-dependently decreased the expression of TLR2, MyD88, IRAK1, IRAK4 and TRAF6 as well as the phosphorylation of TAK1, MKK3/6, p38 MAPK, IκB-α and NF-κB in the mammary gland tissues. In mouse mammary epithelial cells (mMECs) infected by S aureus in vitro, pretreatment with PD dose-dependently suppressed the upregulated pro-inflammatory cytokines and signaling proteins, and the nuclear translocation of NF-κB p65 and AP-1. A TLR2-neutralizing antibody mimicked PD in its suppression on S aureus-induced upregulation of MyD88, p-p38 and p-p65 levels in mMECs. PD (50, 100 μg/mL) affected neither the growth of S aureus in vitro, nor the viability of mMECs. In conclusion, PD does not exhibit antibacterial activity against S aureus, its therapeutic effects in mouse S aureus-induced mastitis depend on its ability to down-regulate pro-inflammatory cytokine levels via inhibiting TLR2-mediated activation of the p38 MAPK/NF-κB signaling pathway. PMID:27890916

  13. IL-36 cytokine expression and its relationship with p38 MAPK and NF-κB pathways in psoriasis vulgaris skin lesions.

    PubMed

    He, Qi; Chen, Hong-xiang; Li, Wen; Wu, Yan; Chen, Shan-juan; Yue, Qing; Xiao, Min; Li, Jia-wen

    2013-08-01

    This study examined the correlation of the expression of interleukin-36 (IL-36), a novel member of interleukin-1 (IL-1) family, with p38 mitogen-activated protein kinase (p38 MAPK) and nuclear factor-kappa B (NF-κB) pathways in psoriasis vulgaris skin lesions. The expression levels of IL-36α, IL-36β, IL-36Γ, phosphorylated p38 MAPK, and NF-κBp65 were detected in the skin tissues of 38 psoriasis patients and 17 healthy control subjects by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting. The cytokine expression levels were compared between the psoriasis group and the control group. A correlation analysis between cytokine proteins was performed in the psoriasis group. Results showed that the expression levels of IL-36a, IL-36β, IL-36Γ, phosphorylated p38 MAPK and NF-κBp65 in the psoriasis group were significantly higher than those in the control group (P<0.001). In the psoriasis group, the IL-36 cytokine expression was positively correlated with phosphorylated p38 MAPK and NF-κBp65 expression (P<0.05). A significant positive correlation was also found between the phosphorylated p38 MAPK and NF-κBp65 expression (P<0.01). It was concluded that the increased IL-36 expression is correlated with p38 MAPK and NF-κB pathways in psoriasis vulgaris skin lesions. All the three factors may be jointly involved in the pathogenesis and local inflammatory response of psoriasis.

  14. p38MAPK, Rho/ROCK and PKC pathways are involved in influenza-induced cytoskeletal rearrangement and hyperpermeability in PMVEC via phosphorylating ERM.

    PubMed

    Zhang, Chenyue; Wu, Ying; Xuan, Zinan; Zhang, Shujing; Wang, Xudan; Hao, Yu; Wu, Jun; Zhang, Shu

    2014-11-04

    Severe influenza infections are featured by acute lung injury, a syndrome of pulmonary microvascular leak. A growing number of evidences have shown that the pulmonary microvascular endothelial cells (PMVEC) are critical target of influenza virus, promoting microvascular leak. It is reported that there are multiple mechanisms by which influenza virus could elicit increased pulmonary endothelial permeability, in both direct and indirect manners. Ezrin/radixin/moesin family proteins, the linkers between plasma membrane and actin cytoskeleton, have been reported to be involved in cell adhesion, motility and may modulate endothelial permeability. Studies have also shown that ERM is phosphorylated in response to various stimuli via p38MAPK, Rho/ROCK or PKC pathways. However, it is unclear that whether influenza infection could induce ERM phosphorylation and its relocalization. In the present study, we have found that there are cytoskeletal reorganization and permeability increases in the course of influenza virus infection, accompanied by upregulated levels of p-ERM. p-ERM's aggregation along the periphery of PMVEC upon influenza virus infection was detected via confocal microscopy. Furthermore, we sought to determine the role of p38MAPK, Rho/ROCK and PKC pathways in ERM phosphorylation as well as their involvement in influenza virus-induced endothelial malfunction. The activation of p38MAPK, Rho/ROCK and PKC pathways upon influenza virus stimulation were observed, as evidenced by the evaluation of phosphorylated p38 (p-p38), phosphorylated MKK (p-MKK) in p38MAPK pathway, ROCK1 in Rho/ROCK pathway and phosphorylated PKC (p-PKC) in PKC pathway. We also showed that virus-induced ERM phosphorylation was reduced by using p38MAPK inhibitor, SB203580 (20 μM), Rho/ROCK inhibitor, Y27632 (20 μM), PKC inhibitor, LY317615 (10 μM). Additionally, influenza virus-induced F-actin reorganization and hyperpermeability were attenuated by pretreatment with SB203580, Y27632 and LY317615

  15. 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.

  16. 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

  17. Eimeria bovis-triggered neutrophil extracellular trap formation is CD11b-, ERK 1/2-, p38 MAP kinase- and SOCE-dependent.

    PubMed

    Muñoz-Caro, Tamara; Mena Huertas, Sandra Jaqueline; Conejeros, Ivan; Alarcón, Pablo; Hidalgo, María A; Burgos, Rafael A; Hermosilla, Carlos; Taubert, Anja

    2015-03-05

    Eimeria bovis is an important coccidian parasite that causes high economic losses in the cattle industry. We recently showed that polymorphonuclear neutrophils (PMN) react upon E. bovis sporozoite exposure by neutrophil extracellular trap (NET) formation. We focused here on the molecular mechanisms that are involved in this process. The sporozoite encounter led to an enhanced surface expression of neutrophil CD11b suggesting a potential role of this receptor in E. bovis-mediated NETosis. Antibody-mediated blockage of CD11b confirmed this assumption and led to a significantly decreased sporozoite-triggered NET. In addition, E. bovis-induced NETosis was found to be Ca(2+)-dependent since the inhibition of store-operated calcium entry (SOCE) significantly diminished NET. Furthermore, NADPH oxidase, neutrophil elastase (NE) and myeloperoxidase (MPO) were confirmed as key molecules in sporozoite-triggered NETosis, as inhibition thereof blocked parasite-triggered NET. PMN degranulation analyses revealed a significant release of matrix metalloprotease-9 containing granules upon sporozoite exposure. We further show a significantly enhanced phosphorylation of ERK1/2 and p38 MAPK in sporozoite-exposed PMN indicating a key role of this signaling pathway in E. bovis-mediated NETosis. Accordingly, ERK 1/2 and p38 MAPK inhibition led to a significant decrease in NET formation. Finally, we demonstrate that sporozoite-induced NETosis is neither a stage-, species-, nor host-specific process.

  18. 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

  19. Involvement of the mannose receptor and p38 mitogen-activated protein kinase signaling pathway of the microdomain of the integral membrane protein after enteropathogenic Escherichia coli infection.

    PubMed

    Liu, Zhihua; Ma, Yanlei; Moyer, Mary Pat; Zhang, Peng; Shi, Chenzhang; Qin, Huanlong

    2012-04-01

    The microdomain of the integral membrane protein (MIMP) has been shown to adhere to mucin and to antagonize the adhesion of enteropathogenic Escherichia coli (EPEC) to epithelial cells; however, the mechanism has not been fully elucidated. In this study, we further identified the receptor of MIMP on NCM460 cells and investigated the mechanism (the p38 mitogen-activated protein kinase [MAPK] pathway) following the interaction of MIMP and its corresponding receptor, mannose receptor. We first identified the target receptor of MIMP on the surfaces of NCM460 cells using immunoprecipitation-mass spectrometry technology. We also verified the mannose receptor and examined the degradation and activation of the p38 MAPK signaling pathway. The results indicated that MIMP adhered to NCM460 cells by binding to the mannose receptor and inhibited the phosphorylation of p38 MAPK stimulated after EPEC infection via inhibition of the Toll-like receptor 5 pathway. These findings indicated that MIMPs relieve the injury of NCM460 cells after enteropathogenic E. coli infection through the mannose receptor and inhibition of the p38 MAPK signaling pathway, both of which may therefore be potential therapeutic targets for intestinal diseases, such as inflammatory bowel disease.

  20. Activation of the p38 signaling pathway by heat shock involves the dissociation of glutathione S-transferase Mu from Ask1.

    PubMed

    Dorion, Sonia; Lambert, Herman; Landry, Jacques

    2002-08-23

    Despite the importance of the stress-activated protein kinase pathways in cell death and survival, it is unclear how stressful stimuli lead to their activation. In the case of heat shock, the existence of a specific mechanism of activation has been evidenced, but the molecular nature of this pathway is undefined. Here, we found that Ask1 (apoptosis signal-regulating kinase 1), an upstream activator of the stress-activated protein kinase p38 during exposure to oxidative stress and other stressful stimuli, was also activated by heat shock. Ask1 activity was required for p38 activation since overexpression of a kinase dead mutant of Ask1, Ask1(K709M), inhibited heat shock-induced p38 activation. The activation of Ask1 by oxidative stress involves the oxidation of thioredoxin, an endogenous inhibitor of Ask1. A different activation mechanism takes place during heat shock. In contrast to p38 induction by H(2)O(2), induction by heat shock was not antagonized by pretreatment with the antioxidant N-acetyl-l-cysteine or by overexpressing thioredoxin and was not accompanied by the dissociation of thioredoxin from Ask1. Instead, heat shock caused the dissociation of glutathione S-transferase Mu1-1 (GSTM1-1) from Ask1 and overexpression of GSTM1-1-inhibited induction of p38 by heat shock. We concluded that because of an alternative regulation by the two distinct repressors thioredoxin and GSTM1-1, Ask1 constitutes the converging point of the heat shock and oxidative stress-sensing pathways that lead to p38 activation.

  1. 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

  2. Kaempferol suppresses cell metastasis via inhibition of the ERK-p38-JNK and AP-1 signaling pathways in U-2 OS human osteosarcoma cells.

    PubMed

    Chen, Hui-Jye; Lin, Chung-Ming; Lee, Chao-Ying; Shih, Nai-Chen; Peng, Shu-Fen; Tsuzuki, Minoru; Amagaya, Sakae; Huang, Wen-Wen; Yang, Jai-Sing

    2013-08-01

    Kaempferol is a natural flavonoid that possesses anti-proliferative and apoptosis-inducing activities in several cancer cell lines. In the present study, we investigated the anti-metastatic activity of kaempferol and its molecular mechanism(s) of action in human osteosarcoma cells. Kaempferol displayed inhibitory effects on the invasion and adhesion of U-2 osteosarcoma (OS) cells in a concentration-dependent manner by Matrigel Transwell assay and cell adhesion assay. Kaempferol also inhibited the migration of U-2 OS cells in a concentration-dependent manner at different treatment time points by wound-healing assay. Additional experiments showed that kaempferol treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase (MMP)-2, MMP-9 and urokinase plasminogen activator (uPA) by gelatin and casein-plasminogen zymography assays and western blot analyses. Kaempferol also downregulated the mRNA levels of MMP-2 and MMP-9 by quantitative PCR analyses. Furthermore, kaempferol was able to reduce the protein phosphorylation of ERK, p38 and JNK by western blotting. By electrophoretic mobility-shift assay (EMSA), we demonstrated that kaempferol decreased the DNA binding activity of AP-1, an action likely to result in the reduced expression of MMP-2, MMP-9 and uPA. Collectively, our data showed that kaempferol attenuated the MAPK signaling pathways including ERK, JNK and p38 and resulted in the decreased DNA binding ability of AP-1, and hence, the downregulation in the expression and enzymatic activities of MMP-2, MMP-9 and uPA, contributing to the inhibition of metastasis of U-2 OS cells. Our results suggest a potential role of kaempferol in the therapy of tumor metastasis of OS.

  3. Actions of 1,25(OH)2-vitamin D3 on the cellular cycle depend on VDR and p38 MAPK in skeletal muscle cells.

    PubMed

    Irazoqui, Ana P; Boland, Ricardo L; Buitrago, Claudia G

    2014-12-01

    Previously, we have reported that 1,25(OH)2-vitamin D3 (1,25D) activates p38 MAPK (p38) in a vitamin D receptor (VDR)-dependent manner in proliferative C2C12 myoblast cells. It was also demonstrated that 1,25D promotes muscle cell proliferation and differentiation. However, we did not study these hormone actions in depth. In this study we have investigated whether the VDR and p38 participate in the signaling mechanism triggered by 1,25D. In C2C12 cells, the VDR was knocked down by a shRNA, and p38 was specifically inhibited using SB-203580. Results from cell cycle studies indicated that hormone stimulation prompts a peak of S-phase followed by an arrest in the G0/G1-phase, events which were dependent on VDR and p38. Moreover, 1,25D increases the expression of cyclin D3 and the cyclin-dependent kinase inhibitors, p21(Waf1/Cip1) and p27(Kip1), while cyclin D1 protein levels did not change during G0/G1 arrest. In all these events, p38 and VDR were required. At the same time, a 1,25D-dependent acute increase in myogenin expression was observed, indicating that the G0/G1 arrest of cells is a pro-differentiative event. Immunocytochemical assays revealed co-localization of VDR and cyclin D3, promoted by 1,25D in a p38-dependent manner. When cyclin D3 expression was silenced, VDR and myogenin levels were downregulated, indicating that cyclin D3 was required for 1,25D-induced VDR expression and the concomitant entrance into the differentiation process. In conclusion, the VDR and p38 are involved in control of the cellular cycle by 1,25D in skeletal muscle cells, providing key information on the mechanisms underlying hormone regulation of myogenesis.

  4. Calcium oxalate crystals induces tight junction disruption in distal renal tubular epithelial cells by activating ROS/Akt/p38 MAPK signaling pathway.

    PubMed

    Yu, Lei; Gan, Xiuguo; Liu, Xukun; An, Ruihua

    2017-11-01

    Tight junction plays important roles in regulating paracellular transports and maintaining cell polarity. Calcium oxalate monohydrate (COM) crystals, the major crystalline composition of kidney stones, have been demonstrated to be able to cause tight junction disruption to accelerate renal cell injury. However, the cellular signaling involved in COM crystal-induced tight junction disruption remains largely to be investigated. In the present study, we proved that COM crystals induced tight junction disruption by activating ROS/Akt/p38 MAPK pathway. Treating Madin-Darby canine kidney (MDCK) cells with COM crystals induced a substantial increasing of ROS generation and activation of Akt that triggered subsequential activation of ASK1 and p38 mitogen-activated protein kinase (MAPK). Western blot revealed a significantly decreased expression of ZO-1 and occludin, two important structural proteins of tight junction. Besides, redistribution and dissociation of ZO-1 were observed by COM crystals treatment. Inhibition of ROS by N-acetyl-l-cysteine (NAC) attenuated the activation of Akt, ASK1, p38 MAPK, and down-regulation of ZO-1 and occludin. The redistribution and dissociation of ZO-1 were also alleviated by NAC treatment. These results indicated that ROS were involved in the regulation of tight junction disruption induced by COM crystals. In addition, the down-regulation of ZO-1 and occludin, the phosphorylation of ASK1 and p38 MAPK were also attenuated by MK-2206, an inhibitor of Akt kinase, implying Akt was involved in the disruption of tight junction upstream of p38 MAPK. Thus, these results suggested that ROS-Akt-p38 MAPK signaling pathway was activated in COM crystal-induced disruption of tight junction in MDCK cells.

  5. SK-N-MC cell death occurs by distinct molecular mechanisms in response to hydrogen peroxide and superoxide anions: involvements of JAK2-STAT3, JNK, and p38 MAP kinases pathways.

    PubMed

    Moslehi, Maryam; Yazdanparast, Razieh

    2013-07-01

    Oxidative stress plays a vital role in the pathogenesis of neurodegenerative diseases. Nerve cells are incessantly exposed to environmental stresses leading to overproduction of some harmful species like reactive oxygen species (ROS). ROS including hydrogen peroxide and superoxide anion are potent inducers of various signaling pathways encompassing MAPKs and JAK-STAT pathways. In the current study, we scrutinized the effects of hydrogen peroxide and/or menadione (superoxide anion generator) on JNK/p38-MAPKs and JAK2-STAT3 pathways to elucidate the mechanism(s) by which each oxidant modulated the above-mentioned pathways leading to SK-N-MC cell death. Our results delineated that hydrogen peroxide and superoxide anion radical induced distinct responses as we showed that STAT3 and p38 were activated in response to hydrogen peroxide, but not superoxide anion radicals indicating the specificity in ROS-induced signaling pathways activations and behaviors. We also observed that menadione induced JNK-dependent p53 expression and apoptotic death in SK-N-MC cells while H2O2-induced JNK activation was p53 independent. Thus, we declare that ROS type has a key role in selective instigation of JNK/p38-MAPKs and JAK2-STAT3 pathways in SK-N-MC cells. Identifying these differential behaviors and mechanisms of hydrogen peroxide and superoxide anion functions illuminates the possible therapeutic targets in the prevention or treatment of ROS-induced neurodegenerative diseases such as Alzheimer's disease.

  6. 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

  7. Over-expressed human TREK-1 inhibits CHO cell proliferation via inhibiting PKA and p38 MAPK pathways and subsequently inducing G1 arrest

    PubMed Central

    Zhang, Man; Yin, Hua-jing; Wang, Wei-ping; Li, Jiang; Wang, Xiao-liang

    2016-01-01

    Aim: Recent studies have shown that the two-pore-domain potassium channel TREK-1 is involved in the proliferation of neural stem cells, astrocytes and human osteoblasts. In this study, we investigated how TREK-1 affected the proliferation of Chinese hamster ovary (CHO) cells in vitro. Methods: A CHO cell line stably expressing hTREK-1 (CHO/hTREK-1 cells) was generated. TREK-1 channel currents in the cells were recorded using whole-cell voltage-clamp recording. The cell cycle distribution was assessed using flow cytometry analysis. The expression of major signaling proteins involved was detected with Western blotting. Results: CHO/hTREK-1 cells had a high level of TREK-1 expression, reached up to 320%±16% compared to the control cells. Application of arachidonic acid (10 μmol/L), chloroform (1 mmol/L) or etomidate (10 μmol/L) substantially increased TREK-1 channel currents in CHO/hTREK-1 cells. Overexpression of TREK-1 caused CHO cells arresting at the G1 phase, and significantly decreased the expression of cyclin D1. The TREK-1 inhibitor l-butylphthalide (1–100 μmol/L) dose-dependently attenuated TREK-1-induced G1 phase cell arrest. Moreover, overexpression of TREK-1 significantly decreased the phosphorylation of Akt (S473), glycogen synthase kinase-3β (S9) and cAMP response element-binding protein (CREB, S133), enhanced the phosphorylation of p38 (T180/Y182), but did not alter the phosphorylation and expression of signal transducer and activator of transcription 3 (STAT3). Conclusion: TREK-1 overexpression suppresses CHO cell proliferation by inhibiting the activity of PKA and p38/MAPK signaling pathways and subsequently inducing G1 phase cell arrest. PMID:27397543

  8. Alpha-1-antitrypsin suppresses oxidative stress in preeclampsia by inhibiting the p38MAPK signaling pathway: An in vivo and in vitro study

    PubMed Central

    Ding, Jian; Yuan, Hua; Yang, Lan; Xu, Jian-Juan; Hu, Ling-Qin

    2017-01-01

    This present study was designed to investigate the effects of alpha-1-antitrypsin (AAT) on oxidative stress in preeclampsia (PE) by regulating p38 mitogen-activated protein kinase (p38MAPK) signaling pathway. HTR8/SVneo cells were randomly assigned into normal, hypoxia/reoxygenation (H/R), HR + AAT and HR + siRNA-AAT groups. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to detect the mRNA and protein expressions of p-p38MAPK, AAT, signal transducer and activator of transcription 1 (STAT1) and activating transcription factor2 (ATF2). Flow cytometry, scratch test, cell counting kit-8 (CCK-8) assay and the 3-(4,5)-dimethylthiazol (-z-y1)-3,5-di- phenyltetrazolium bromide (MTT) assay were conducted to detect reactive oxygen species (ROS) and cell apoptosis, cell migration, proliferation and cytotoxicity, respectively. Mouse models in PE were established, which were divided into normal pregnancy (NP), PE and PE + AAT groups with blood pressure and urine protein measured. Chromatin immunoprecipitation (ChIP) and enzyme-linked immunosorbent assay (ELISA) were conducted to detect the activity of oxidative stress-related kinases and expressions of inflammatory cytokines and coagulation-related factors in cells and mice placenta. Immunohistochemistry, Western blotting and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were performed to detect AAT and p38MAPK expressions, apoptosis-related protein expressions, and apoptosis rate in mice placenta. Compared with the normal group, the H/R group had decreased expression of AAT, activity of superoxide dismutase (SOD) and GSH-Px, cell proliferation and migration, but increased p38MAPK, STAT1, ATF2, MDA, H2O2, inflammatory cytokines, coagulation-related factors, cell cytotoxicity, ROS, apoptotic factors and apoptosis rate. Compared with the H/R group, the HR + ATT group had increased expressions of AAT, activity of SOD and GSH-Px, cell proliferation and

  9. 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.

  10. Lantana macrophylla Schauer (Verbenaceae) ethanolic extract induces activation of ERK1/2 and p38 MAPKs pathway and Ca2+ imbalance in human trophoblasts derived cell lines.

    PubMed

    da Conceição, Aline O; de Oliveira, Fernando F; de Oliveira, Rosilene A; de J da S Junior, Ademir; Takser, Larissa; Reyes-Moreno, Carlos; Lafond, Julie

    2012-03-01

    Lantana macrophylla Schauer (Verbenaceae) a medicinal plant used to treat menstrual and respiratory disorders was investigated. The ethanolic extract from leaves was subjected to phytochemical and biological analysis. BeWo and JEG-3 cells were used to evaluate human chorionic gonadotropin hormone (hCG) production, syncytial formation, Ca2+ uptake and Ca2+ handling protein expression. The cAMP production and the mitogen-activated protein kinases (MAPKs) phosphorylation were also investigated. Phytochemical analysis yield three triterpenes: oleanolic, ursolic and latonolic acid. Viability assay showed no significant cytotoxic effect. A significant decrease in hCG production but not a disturbance on BeWo cell fusion were observed. The cAMP pathway was not affected by L. macrophylla extract alone; although the cAMP production inducted by forskolin was diminished. Both ERK1/2 and p38 MAPKs pathways were activated. Increased intracellular Ca2+ concentration ([Ca2+]i) was observed after 24 h treatment in a time and dose dependent manner; however only L. macrophylla at 10 μg/mL induced increased [Ca2+]i after 10 min treatment. CaBP28K and PMCA1/4 were modulated at protein and mRNA levels, respectively. This study showed for the first time the effect of triterpenoids from L. macrophylla leaves on trophoblasts-like cells and indicates a potential toxic effect of this plant in the placental development and fetal growth.

  11. Taiwanin E inhibits cell migration in human LoVo colon cancer cells by suppressing MMP-2/9 expression via p38 MAPK pathway.

    PubMed

    Hsu, Hsi-Hsien; Kuo, Wei-Wen; Day, Cecilia Hsuan; Shibu, Marthandam Asokan; Li, Shin-Yi; Chang, Sheng-Huang; Shih, Hui-Nung; Chen, Ray-Jade; Viswanadha, Vijaya Padma; Kuo, Yueh-Hsiung; Huang, Chih-Yang

    2016-11-03

    Taiwanin E is a natural compound which is structurally analogous to estrogen II and is abundantly found in Taiwania cryptomerioides. It has been previously reported for its anticancer effects; however, the pharmaceutical effect of Taiwanin E on Human LoVo colon cancer cells is not clear. In this study, we investigated the effects of Taiwanin E on metastasis and the associated mechanism of action on Human LoVo colon cancer cells with respect to the modulations in their cell migration and signaling pathways associated with migration. The results showed that Taiwanin E inhibited cell migration ability correlated with reduced expression and activity of MMP-2 and MMP-9. In addition, Taiwanin E induced activation of p38 through phosphorylation. Inhibition of p38α/β significantly abolished the effect of Taiwanin E on cell migration and MMP-2/-9 activity. Our results conclude that Taiwanin E inhibited cell migration chiefly via p38α MAPK pathway and in a lesser extend via p38β MAPK. The results elucidate the potential of the phytoestrogen natural compound Taiwanin E as a cancer therapeutic agent in inhibiting the cell migration. © 2016 Wiley Periodicals, Inc. Environ Toxicol, 2016.

  12. 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

  13. Overexpression of the wip1 gene abrogates the p38 MAPK/p53/Wip1 pathway and silences p16 expression in human breast cancers.

    PubMed

    Yu, Eunsil; Ahn, Yeon Sun; Jang, Se Jin; Kim, Mi-Jung; Yoon, Ho Sung; Gong, Gyungyub; Choi, Jene

    2007-03-01

    Wild-type p53-induced phosphatase (Wip1 or PPM1D) is a serine/threonine protein phosphatase expressed under various stress conditions, which selectively inactivates p38 MAPK. The finding that this gene is amplified in association with frequent gain of 17q21-24 in breast cancers supports its role as a driver oncogene. However, the pathogenetic mechanism of the wip1 gene expression in breast carcinogenesis remains to be elucidated. In this study, we examine Wip1 mRNA and protein expression in 20 breast cancer tissues and six cell lines. We additionally investigate the relationship among Wip1, active p38 MAPK, p53, and p16 proteins. In our experiments, Wip1 mRNA was significantly upregulated in 7 of 20 (35%) invasive breast cancer samples. Overexpression of Wip1 was inversely correlated with that of active (phosphor-) p38 MAPK (P = 0.007). Furthermore, Wip1-overexpressing tumors exhibited no or low levels of p16, which normally accumulates upon p38 MAPK activation (P = 0.057). Loss of p16 expression was not associated with hypermethylation of its promoter or loss of heterozygosity on 9p21. Among the 135 primary breast carcinomas further examined, a significant association was found between the Wip1 overexpression and negative staining for p53 (P value = 0.057), indicating that the tumors are wild-type for p53. This is first report showing that Wip1 overexpression abrogates the homeostatic balance maintained through the p38-p53-Wip1 pathway, and contributes to malignant progression by inactivating wild-type p53 and p38 MAPK as well as decreasing p16 protein levels in human breast tissues.

  14. DA-9601, a standardized extract of Artemisia asiatica, blocks TNF-α-induced IL-8 and CCL20 production by inhibiting p38 kinase and NF-κB pathways in human gastric epithelial cells

    PubMed Central

    Choi, Suck-Chei; Choi, Eun-Ju; Oh, Hyun-Mee; Lee, SungGa; Lee, Jeong-Kun; Lee, Meung-Su; Shin, Yong-Il; Choi, Suck-Jun; Chae, Jeong-Ryong; Lee, Kang-Min; Lee, Won-Jung; Park, Jae-Sik; Shin, Chang-Yell; Oh, Tae-Young; Jun, Chang-Duk

    2006-01-01

    AIM: To investigate whether, or how, DA-9601, which is a new gastroprotective agent, inhibits TNF-α-induced inflammatory signals in gastric epithelial AGS cells. METHODS: Cell viability was determined by MTT assay. IL-8 and CCL20 promoter activities were determined by a luciferease reporter gene assay. NF-κB-dependent transcriptional activity was determined by I-κBα degradation, NF-κB p65 nuclear translocation and a luciferase activity assay. IL-8 and CCL20 gene expression and protein secretion were determined by RT-PCR and an enzyme-linked immunosorbent assay (ELISA). Total and phosphorylated forms of mitogen-activated protein kinases (MAPKs) were determined by Western blot. RESULTS: Treatment of AGS cells with DA-9601 reduced TNF-α-induced IL-8 and CCL20 promoter activities, as well as their gene expression and protein release. TNF-α also induced NF-κB-dependent transcriptional activity in AGS cells. In contrast, in cells treated with DA-9601, TNF-α-induced NF-κB activity was significantly blocked. Although all three MAP kinase family members were phosphorylated in response to TNF-α, a selective inhibitor of p38 kinase SB203580 only could inhibit both NF-κB-dependent transcriptional activity and IL-8 and CCL20 production, suggesting a potential link between p38 kinase and NF-κB-dependent pathways in AGS cells. Interestingly, DA-9601 also selectively inhibited p38 kinase phosphorylation induced by TNF-α. CONCLUSION: DA-9601 blocked TNF-α-mediated inflammatory signals by potentially modulating the p38 kinase pathway and/or a signal leading to NF-κB-dependent pathways in gastric epithelial cells. PMID:16937467

  15. The PI3 kinase, p38 SAP kinase, and NF-kappaB signal transduction pathways are involved in the survival and maturation of lipopolysaccharide-stimulated human monocyte-derived dendritic cells.

    PubMed

    Ardeshna, K M; Pizzey, A R; Devereux, S; Khwaja, A

    2000-08-01

    As a dendritic cell (DC) matures, it becomes more potent as an antigen-presenting cell. This functional change is accompanied by a change in DC immunophenotype. The signal transduction events underlying this process are poorly characterized. In this study, we have investigated the signal transduction pathways involved in the lipopolysaccharide (LPS)-induced maturation of human monocyte-derived DCs (MoDCs) in vitro. We show that exposure of immature MoDCs to LPS activates the p38 stress-activated protein kinase (p38SAPK), extracellular signal-regulated protein kinase (ERK), phosphoinositide 3-OH kinase (PI3 kinase)/Akt, and nuclear factor (NF)-kappaB pathways. Studies using inhibitors demonstrate that PI3 kinase/Akt but not the other pathways are important in maintaining survival of LPS-stimulated MoDCs. Inhibiting p38SAPK prevented activation of the transcription factors ATF-2 and CREB and significantly reduced the LPS-induced up-regulation of CD80, CD83, and CD86, but did not have any significant effect on the LPS-induced changes in macropinocytosis or HLA-DR, CD40, and CD1a expression. Inhibiting the NF-kappaB pathway significantly reduced the LPS-induced up-regulation of HLA-DR as well as CD80, CD83, and CD86. Inhibiting the p38SAPK and NF-kappaB pathways simultaneously had variable effects depending on the cell surface marker studied. It thus appears that different aspects of LPS-induced MoDC maturation are regulated by different and sometimes overlapping pathways.

  16. [Regulatory mechanism of p38MAPK signaling pathway on renal tissue inflammation in chronic kidney disease and interventional effect of traditional Chinese medicine].

    PubMed

    Zhao, Qing; Wan, Yigang; Wang, Chaojun; Wei, Qingxue; Chen, Haoli; Meng, Xianjie; Yao, Jian

    2012-06-01

    The inflammatory reaction of renal tissues and its relevant tissue damages (such as glomerulosclerosis and renal interstitial fibrosis) are important factors for the development of chronic kidney diseases (CKD) to end-state renal diseases. Of them, p38 mitogen-activated protein kinase (MAPK) signaling pathway plays an important role in regulating expression and bioactivity of multiple nuclear transcription factors, impacting synthesis of downstream inflammatory mediators and activating inflammatory cells. Some monomer traditional Chinese medicines and their extracts (such as emodin and berberine) and some traditional Chinese medicine compound prescriptions (such as Yishen Huoxue decoction) can affect inflammatory reaction of renal tissues by regulating p38MAPK signaling pathway, thas improving reduce glomerulus and renal interstitial inflammatory injury.

  17. A Porphyra columbina hydrolysate upregulates IL-10 production in rat macrophages and lymphocytes through an NF-κB, and p38 and JNK dependent mechanism.

    PubMed

    Cian, Raúl E; López-Posadas, Rocío; Drago, Silvina R; Sánchez de Medina, Fermín; Martínez-Augustin, Olga

    2012-10-15

    The marine environment represents a relatively untapped source of functional ingredients. Here we characterise a hydrolysate obtained from Phorphyra columbina (PcRH) and its effects on primary splenocytes, macrophages and T lymphocytes in vitro. Our product had a high degree of hydrolysis, due to the use of a mixture of endo-peptidase and exo-peptidase, and was enriched in Asp, Ala and Glu. PcRH had mitogenic effects on rat splenic lymphocytes. IL-10 secretion was enhanced by PcRH in splenocytes (235%), macrophages (150%) and in lymphocytes (472%), while the production of TNFα and other proinflammatory cytokines by macrophages was inhibited (15-75%), especially under lipopolysaccharide stimulation. The effect of the hydrolysate on IL-10 was evoked by JNK, p38 MAPK and NF-κB dependent pathways in T lymphocytes. We conclude that PcRH has immunomodulatory effects on macrophages and lymphocytes, activating NF-κB and MAPK dependent pathways, and predominantly inducing IL-10 production.

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

    PubMed

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

    2016-01-25

    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.

  19. 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

  20. Down-regulation of miR-125a-5p is associated with salivary adenoid cystic carcinoma progression via targeting p38/JNK/ERK signal pathway

    PubMed Central

    Liang, Yancan; Ye, Jiantao; Jiao, Jiuyang; Zhang, Jin; Lu, Yingjuan; Zhang, Li; Wan, Di; Duan, Liming; Wu, You; Zhang, Bin

    2017-01-01

    Salivary adenoid cystic carcinoma (SACC) is a relatively uncommon epithelial-like malignancy that can occur in the head and neck region. Despite its slow growth, this aggressive salivary gland tumor frequently recurs and metastasizes to distant organs since lacking effective chemotherapy treatment. MicroRNAs are key regulators in tumor metastasis and progression, but their roles during SACC progression have not been illustrated. In current study, we demonstrate that miR-125a-5p is down-regulated in SACC and closely related to the metastasis and progression in human SACC specimens. In vitro, miR-125a-5p mimic can suppress SACC cell migration and invasion; while blocking miR-125a-5p can relieve the inhibition effect. By using dual-luciferase assay, we confirmed that miR-125a-5p directly targeted to p38 and tissue samples of patients indicated the negative correlation between miR-125a-5p and p38; clinical analysis also showed that low level expression of miR-125a-5p is closely associated with poor prognosis of SACC. Furthermore, down-regulation of miR-125a-5p triggered downstream p38/JNK/ERK activation. Taken together, our results indicate that down-regulation of miR-125a-5p promotes SACC progression through p38 signal pathway and miR-125a-5p can be a potential therapeutic target of SACC. PMID:28386337

  1. PSM Peptides of Staphylococcus aureus Activate the p38-CREB Pathway in Dendritic Cells, Thereby Modulating Cytokine Production and T Cell Priming.

    PubMed

    Armbruster, Nicole S; Richardson, Jennifer R; Schreiner, Jens; Klenk, Juliane; Günter, Manina; Kretschmer, Dorothee; Pöschel, Simone; Schenke-Layland, Katja; Kalbacher, Hubert; Clark, Kristopher; Autenrieth, Stella E

    2016-02-01

    The challenging human pathogen Staphylococcus aureus has highly efficient immune evasion strategies for causing a wide range of diseases, from skin and soft tissue to life-threatening infections. Phenol-soluble modulin (PSM) peptides are major pathogenicity factors of community-associated methicillin-resistant S. aureus strains. In previous work, we demonstrated that PSMs in combination with TLR2 ligand from S. aureus induce tolerogenic dendritic cells (DCs) characterized by the production of high amounts of IL-10, but no proinflammatory cytokines. This in turn promotes the activation of regulatory T cells while impairing Th1 response; however, the signaling pathways modulated by PSMs remain elusive. In this study, we analyzed the effects of PSMs on signaling pathway modulation downstream of TLR2. TLR2 stimulation in combination with PSMα3 led to increased and prolonged phosphorylation of NF-κB, ERK, p38, and CREB in mouse bone marrow-derived DCs compared with single TLR2 activation. Furthermore, inhibition of p38 and downstream MSK1 prevented IL-10 production, which in turn reduced the capacity of DCs to activate regulatory T cells. Interestingly, the modulation of the signaling pathways by PSMs was independent of the known receptor for PSMs, as shown by experiments with DCs lacking the formyl peptide receptor 2. Instead, PSMs penetrate the cell membrane most likely by transient pore formation. Moreover, colocalization of PSMs and p38 was observed near the plasma membrane in the cytosol, indicating a direct interaction. Thus, PSMs from S. aureus directly modulate the signaling pathway p38-CREB in DCs, thereby impairing cytokine production and in consequence T cell priming to increase the tolerance toward the pathogen.

  2. Label Transfer Reagents to Probe p38 MAPK Binding Partners

    PubMed Central

    Andrews, Simeon S.; Hill, Zachary B.; Perera, B. Gayani K.; Maly, Dustin J.

    2013-01-01

    Protein kinases are essential enzymes for cellular signalling, and are often regulated by participation in protein complexes. The mitogen-activated protein kinase (MAPK) p38 is involved in multiple pathways, and its regulation depends on its interactions with other signalling proteins. However, the identification of p38 interacting proteins is challenging. For this reason, we have developed label transfer reagents (LTRs) which allow labelling of p38 signalling complexes. These LTRs leverage the potency and selectivity of known p38 inhibitors to place a photo-crosslinker and tag in the vicinity of p38 and its binding partners. Upon UV irradiation, proteins that are in close proximity to p38 are covalently crosslinked, and labelled proteins are detected and/or purified through an orthogonal chemical handle. Here we demonstrate that p38-selective LTRs selectively label a diversity of p38 binding partners, including substrates, activators, and inactivators. Furthermore, these LTRs can be used in immunoprecipitations to provide low-resolution structural information on p38-containing complexes. PMID:23319368

  3. GBE50 Attenuates Inflammatory Response by Inhibiting the p38 MAPK and NF-κB Pathways in LPS-Stimulated Microglial Cells

    PubMed Central

    He, Gai-ying; Yuan, Chong-gang; Hao, Li; Xu, Ying; Zhang, Zhi-xiong

    2014-01-01

    Overactivated microglia contribute to a variety of pathological conditions in the central nervous system. The major goal of the present study is to evaluate the potential suppressing effects of a new type of Ginko biloba extract, GBE50, on activated microglia which causes proinflammatory responses and to explore the underlying molecular mechanisms. Murine BV2 microglia cells, with or without pretreatmentof GBE50 at various concentrations, were activated by incubation with lipopolysaccharide (LPS). A series of biochemical and microscopic assays were performed to measure cell viability, cell morphology, release of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and signal transduction via the p38 MAPK and nuclear factor-kappa B (NF-κB) p65 pathways. We found that GBE50 pretreatment suppressed LPS-induced morphological changes in BV2 cells. Moreover, GBE50 treatment significantly reduced the release of proinflammatory cytokines, TNF-α and IL-1β, and inhibited the associated signal transduction through the p38 MAPK and NF-κB p65 pathways. These results demonstrated the anti-inflammatory effect of GBE50 on LPS-activated BV2 microglia cells, and indicated that GBE50 reduced the LPS-induced proinflammatory TNF-α and IL-1β release by inhibiting signal transduction through the NF-κB p65 and p38 MAPK pathways. Our findings reveal, at least in part, the molecular basis underlying the anti-inflammatory effects of GBE50. PMID:24782908

  4. Curcumin attenuates BPA-induced insulin resistance in HepG2 cells through suppression of JNK/p38 pathways.

    PubMed

    Geng, Shanshan; Wang, Shijia; Zhu, Weiwei; Xie, Chunfeng; Li, Xiaoting; Wu, Jieshu; Zhu, Jianyun; Jiang, Ye; Yang, Xue; Li, Yuan; Chen, Yue; Wang, Xiaoqian; Meng, Yu; Zhu, Mingming; Wu, Rui; Huang, Cong; Zhong, Caiyun

    2017-03-12

    Bisphenol A (BPA) is an artificial environmental endocrine disrupting chemicals. Accumulating evidence indicates that exposure to BPA contributes to insulin resistance through diverse mechanism including inflammation and oxidative stress. Previous studies have suggested curcumin as a safe phytochemical which can improve obesity-related insulin resistance, inflammation and oxidative stress. The present study aimed to investigate the ability of curcumin to prevent BPA-induced insulin resistance in vitro and the underlying mechanism. Following the establishmet of in vitro insulin resistance via BPA treatment in human liver HepG2 cells, the protective effects of curcumin were determiend. We showed that treatment of HepG2 cells with 100nM BPA for 5days induced significantly decreased glucose consumption, impaired insulin signaling, elevation of pro-inflammatory cytokines and oxidative stress, and activation of signaling pathways; inhibition of JNK and p38 pathways, but not ERK nor NF-κB pathways, improved glucose consumption and insulin signaling in BPA-treated HepG2 cells. Moreover, we revealed that curcumin effectively attenuated the spectrum of effects of BPA-triggered insulin resistance, whereas pretreatment with JNK and p38 agonist anisomycin could significantly compensate the effects caused by curcumin. These data illustrated the role of JNK/p38 activation in BPA-induced insulin resistance and suggested curcumin as a promising candidate for the intervention of BPA-induced insulin resistance.

  5. Silymarin attenuates cigarette smoke extract-induced inflammation via simultaneous inhibition of autophagy and ERK/p38 MAPK pathway in human bronchial epithelial cells

    PubMed Central

    Li, Diandian; Hu, Jun; Wang, Tao; Zhang, Xue; Liu, Lian; Wang, Hao; Wu, Yanqiu; Xu, Dan; Wen, Fuqiang

    2016-01-01

    Cigarette smoke (CS) is a major risk of chronic obstructive pulmonary disease (COPD), contributing to airway inflammation. Our previous study revealed that silymarin had an anti-inflammatory effect in CS-exposed mice. In this study, we attempt to further elucidate the molecular mechanisms of silymarin in CS extract (CSE)-induced inflammation using human bronchial epithelial cells. Silymarin significantly suppressed autophagy activation and the activity of ERK/p38 mitogen-activated protein kinase (MAPK) pathway in Beas-2B cells. We also observed that inhibiting the activity of ERK with specific inhibitor U0126 led to reduced autophagic level, while knockdown of autophagic gene Beclin-1 and Atg5 decreased the levels of ERK and p38 phosphorylation. Moreover, silymarin attenuated CSE-induced upregulation of inflammatory cytokines TNF-α, IL-6 and IL-8 which could also be dampened by ERK/p38 MAPK inhibitors and siRNAs for Beclin-1 and Atg5. Finally, we validated decreased levels of both autophagy and inflammatory cytokines (TNF-α and KC) in CS-exposed mice after silymarin treatment. The present research has demonstrated that CSE-induced autophagy in bronchial epithelia, in synergism with ERK MAPK pathway, may initiate and exaggerate airway inflammation. Silymarin could attenuate inflammatory responses through intervening in the crosstalk between autophagy and ERK MAPK pathway, and might be an ideal agent treating inflammatory pulmonary diseases. PMID:27874084

  6. Transforming growth factor type beta 1 increases the expression of angiotensin II receptor type 2 by a SMAD- and p38 MAPK-dependent mechanism in skeletal muscle.

    PubMed

    Painemal, Paula; Acuña, María José; Riquelme, Cecilia; Brandan, Enrique; Cabello-Verrugio, Claudio

    2013-01-01

    Excessive deposition of extracellular matrix (ECM) proteins, a condition known as fibrosis, is a hallmark of Duchenne muscular dystrophy. Among the factors that trigger muscle fibrosis are transforming growth factor beta (TGF-β) and angiotensin II (Ang-II). Ang-II belongs to the renin-angiotensin system, and its biological effects are exerted by Ang-II receptors type 1 and type 2 (AT-1 and AT-2, respectively). This study aims to determine the effect of TGF-β1 on the expression of AT-1 and AT-2 receptor in skeletal muscle. C2 C12 myoblasts exposed to TGF-β1 showed a dose-dependent increase in AT-2 expression but with no effect on AT-1 levels. Injection of TGF-β1 in the skeletal muscle of mice increased the levels of AT-2 and ECM protein but unchanged AT-1 levels. We also detected higher expression levels of AT-2 receptor in dystrophic skeletal muscle of mdx mice than in normal mice. The induction of AT-2 was mediated by the canonical TGF-β pathway because under the inhibitory conditions of the kinase activity of TGFβ receptor I or the knockdown of Smad2/3 levels, TGF-β-induced AT-2 receptor increase was strongly inhibited. Furthermore, we demonstrated that p38MAPK activity in response to TGF-β is also required for AT-2 increase as evaluated by a p38MAPK inhibitor. Our results show that the levels of AT-2 but not AT-1 receptor are modulated by the pro-fibrotic factor TGF-β1 in myoblasts and mouse skeletal muscle. This finding suggests that AT-2 might be involved in the physiopathology of fibrosis in dystrophic skeletal muscle.

  7. Thimerosal-induced apoptosis in human SCM1 gastric cancer cells: activation of p38 MAP kinase and caspase-3 pathways without involvement of [Ca2+]i elevation.

    PubMed

    Liu, Shiuh-Inn; Huang, Chorng-Chih; Huang, Chun-Jen; Wang, Being-Whey; Chang, Po-Min; Fang, Yi-Chien; Chen, Wei-Chuan; Wang, Jue-Long; Lu, Yih-Chau; Chu, Sau-Tung; Chou, Chiang-Ting; Jan, Chung-Ren

    2007-11-01

    Thimerosal is a mercury-containing preservative in some vaccines. The effect of thimerosal on human gastric cancer cells is unknown. This study shows that in cultured human gastric cancer cells (SCM1), thimerosal reduced cell viability in a concentration- and time-dependent manner. Thimerosal caused apoptosis as assessed by propidium iodide-stained cells and caspase-3 activation. Although immunoblotting data revealed that thimerosal could activate the phosphorylation of extracellular signal-regulated kinase, c-Jun NH2-terminal protein kinase, and p38 mitogen-activated protein kinase (p38 MAPK), only SB203580 (a p38 MAPK inhibitor) partially prevented cells from apoptosis. Thimerosal also induced [Ca2+](i) increases via Ca2+ influx from the extracellular space. However, pretreatment with (bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetate)/AM, a Ca2+ chelator, to prevent thimerosal-induced [Ca2+](i) increases did not protect cells from death. The results suggest that in SCM1 cells, thimerosal caused Ca2+-independent apoptosis via phosphorylating p38 MAPK resulting in caspase-3 activation.

  8. 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.

  9. 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.

  10. Tat engagement of p38 MAP kinase and IRF7 pathways leads to activation of interferon-stimulated genes in antigen-presenting cells.

    PubMed

    Kim, Nayoung; Kukkonen, Sami; Martinez-Viedma, Maria Del Pilar; Gupta, Sumeet; Aldovini, Anna

    2013-05-16

    As a result of its interaction with transcription factors, HIV type 1 (HIV-1) Tat can modulate the expression of both HIV and cellular genes. In antigen-presenting cells Tat induces the expression of a subset of interferon (IFN)-stimulated genes (ISGs) in the absence of IFNs. We investigated the genome-wide Tat association with promoters in immature dendritic cells and in monocyte-derived macrophages. Among others, Tat associated with the MAP2K6, MAP2K3, and IRF7 promoters that are functionally part of IL-1 and p38 mitogen-activated protein kinase (MAPK) signaling pathways. The association correlated with their increased gene expression, increased activation of p38 MAPK and of phosphorylated signal transducer and activator of transcription 1 (STAT1), and consequent induction of ISGs. Probing these pathways with RNA interference, pharmacological p38 MAPK inhibition, and in cell lines lacking STAT1s or the type I IFN receptor chain confirmed the role of MAPKKs and IRF7 in Tat-mediated modulation of ISGs and excluded the involvement of IFNs in this modulation. Tat interaction with the 2 MAPKK and IRF7 promoters in HIV-1-infected cells and the resulting persistent activation of ISGs, which include inflammatory cytokines and chemokines, can contribute to the increased immune activation that characterizes HIV infection.

  11. 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.

  12. Anticancer drugs induce hypomethylation of the acetylcholinesterase promoter via a phosphorylated-p38-DNMT1-AChE pathway in apoptotic hepatocellular carcinoma cells.

    PubMed

    Xi, Qiliang; Gao, Ning; Yang, Yang; Ye, Weiyuan; Zhang, Bo; Wu, Jun; Jiang, Gening; Zhang, Xuejun

    2015-11-01

    Apoptosis, also known as programmed cell death, plays an essential role in eliminating excessive, damaged or harmful cells. Previous work has demonstrated that anticancer drugs induce cell apoptosis by inducing cytotoxicity. In recent years, several reports demonstrated modulated expression of DNA methyltransferases 1 (DNMT1) and acetylcholinesterase (AChE) in a variety of tumors. In this study, we showed that the expression of DNMT1 was decreased and the methylation of CpGs in the promoter of AChE was reduced in anticancer drugs-induced apoptotic hepatocellular carcinoma cells. Silencing of DNMT1 expression by AZA or RNA interference (RNAi) restored AChE production and inhibition of AChE expression by RNAi protected HCC cells from anticancer drugs-induced apoptosis. Furthermore, we demonstrated that the regulation of AChE by DNMT1 was involved in the phosphorylated p38 pathway in anticancer drugs-induced apoptosis. In addition, immunohistochemical staining showed that P-p38, DNMT1 and AChE were aberrantly expressed in a subset of HCC tumors. Taken together, we demonstrated the regulation of AChE by DNMT1 and further, we found that this regulation was involved in the phosphorylated p38 pathway in anticancer drugs-induced apoptosis.

  13. Inhibition of prostate cancer growth by solanine requires the suppression of cell cycle proteins and the activation of ROS/P38 signaling pathway.

    PubMed

    Pan, Bin; Zhong, Weifeng; Deng, Zhihai; Lai, Caiyong; Chu, Jing; Jiao, Genlong; Liu, Junfeng; Zhou, Qizhao

    2016-11-01

    Solanine, a naturally steroidal glycoalkaloid in nightshade (Solanum nigrum Linn.), can inhibit proliferation and induce apoptosis of tumor cells. However, the mechanism of solanine-suppressing prostate cancer cell growth remains to be elucidated. This study investigates the inhibition mechanism of solanine on cancer development in vivo and in cultured human prostate cancer cell DU145 in vitro. Results show that solanine injection significantly suppresses the tumor cell growth in xenograft athymic nude mice. Solanine regulates the protein levels of cell cycle proteins, including Cyclin D1, Cyclin E1, CDK2, CDK4, CDK6, and P21 in vivo and in vitro. Also, in cultured DU145 cell, solanine significantly inhibits cell growth. Moreover, the administration of NAC, an active oxygen scavenger, markedly reduces solanine-induced cell death. Blockade of P38 MAPK kinase cannot suppress reactive oxygen species (ROS), but can suppress solanine-induced cell apoptosis. Also, inhibition of ROS by NAC inactivates P38 pathway. Taken together, the data suggest that inhibition of prostate cancer growth by solanine may be through blocking the expression of cell cycle proteins and inducing apoptosis via ROS and activation of P38 pathway. These findings indicate an attractive therapeutic potential of solanine for suppression of prostate cancer.

  14. p38/Sp1/Sp4/HDAC4/BDNF Axis Is a Novel Molecular Pathway of the Neurotoxic Effect of the Methylmercury

    PubMed Central

    Guida, Natascia; Laudati, Giusy; Mascolo, Luigi; Valsecchi, Valeria; Sirabella, Rossana; Selleri, Carmine; Di Renzo, Gianfranco; Canzoniero, Lorella M. T.; Formisano, Luigi

    2017-01-01

    The molecular pathways involved in methylmercury (MeHg)-induced neurotoxicity are not fully understood. Since pan-Histone deacetylases (HDACs) inhibition has been found to revert the neurodetrimental effect of MeHg, it appeared of interest to investigate whether the pattern of HDACs isoform protein expression is modified during MeHg-induced neurotoxicity and the transcriptional/transductional mechanisms involved. SH-SY5Y neuroblastoma cells treated with MeHg 1 μM for 12 and 24 h showed a significant increase of HDAC4 protein and gene expression, whereas the HDACs isoforms 1–3, 5, and 6 were unmodified. Furthermore, MeHg-induced HDAC4 increase was reverted when cells were transfected with siRNAs against specificity protein 1 (Sp1) and Sp4, that were both increased during MeHg exposure. Next we studied the role of extracellular-signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK), and p38 mitogen-activated protein kinases (MAPKs) in MeHg—induced increase of Sp1, Sp4, and HDAC4 expression. As shown by Western Blot analysis MeHg exposure increased the phosphorylation of p38, but not of ERK and JNK. Notably, when p38 was pharmacologically blocked, MeHg-induced Sp1, Sp4 protein expression, and HDAC4 protein and gene expression was reverted. In addition, MeHg exposure increased the binding of HDAC4 to the promoter IV of the Brain-derived neurotrophic factor (BDNF) gene, determining its mRNA reduction, that was significantly counteracted by HDAC4 knocking down. Furthermore, rat cortical neurons exposed to MeHg (1 μM/24 h) showed an increased phosphorylation of p38, in parallel with an up-regulation of Sp1, Sp4, and HDAC4 and a down-regulation of BDNF proteins. Importantly, transfection of siRNAs against p38, Sp1, Sp4, and HDAC4 or transfection of vector overexpressing BDNF significantly blocked MeHg-induced cell death in cortical neurons. All these results suggest that p38/Sp1-Sp4/HDAC4/BDNF may represent a new pathway involved in Me

  15. Sulfur Mustard Induced Cytokine Production and Cell Death: Investigating the Potential Roles of the p38, p53, and NF-kappaB Signaling Pathways with RNA Interference

    DTIC Science & Technology

    2010-01-01

    vation pathway in cytokine production in SM-exposed NHEK. Although there are some exceptions, the clas- sical NF-κB activation pathway with the p50–p65...military campaigns since the First World War. Skin is a major target tissue, and clin- ical presentations of SM cutaneous injuries are char- acterized by...3,5]. Both p38 and NF-κB are activated in SM-exposed cells [7,9–11], but it is NF-κB that has long been im- plicated as playing a primary role in SM

  16. Artocarpol A stimulation of superoxide anion generation in neutrophils involved the activation of PLC, PKC and p38 mitogen-activated PK signaling pathways.

    PubMed

    Kuan, Yu-Hsiang; Lin, Ruey-Hseng; Tsao, Lo-Ti; Lin, Chun-Nan; Wang, Jih-Pyang

    2005-06-01

    1 Artocarpol A (ART), a natural phenolic compound isolated from Artocarpus rigida, stimulated a slow onset and long-lasting superoxide anion generation in rat neutrophils, whereas only slightly activated the NADPH oxidase in a cell-free system. 2 Pretreatment of neutrophils with pertussis toxin (1 microg ml(-1)), 50 microM 2'-amino-3'-methoxyflavone (PD 98059), or 1 microM 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene (U0126) had no effect on ART-stimulated superoxide anion generation. ART (30 microM) did not induce extracellular signal-regulated kinase (ERK) phosphorylation. 3 4-(4-Fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole (SB 203580) markedly attenuated the ART-stimulated superoxide anion generation (IC50 value of 4.3+/-0.3 microM). Moreover, ART induced p38 mitogen-activated PK (MAPK) phosphorylation and activation. 4 The superoxide anion generation in response to ART was also substantially inhibited in a Ca2+-free medium, and by pretreatment with 1 microM 1-[6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl]-1H-pyrrole-2,5-dione (U-73122) and 100 microM 2-aminoethyldiphenyl borate (2-APB). ART (30 microM) stimulated the [Ca2+]i elevation in the presence or absence of external Ca2+, and also increased the D-myo-inositol 1,4,5-trisphosphate formation. 5 2-[1-(3-Dimethylaminopropyl)-1H-indol-3-yl]-3-(1H-indol-3-yl)-maleimide (GF 109203X) greatly inhibited the ART-stimulated superoxide anion generation (IC50 value of 7.8+/-1.0 nM). ART increased the recruitment of PKC-alpha, -betaI, and -betaII to the plasma membrane of neutrophils, and stimulated Ca2+-dependent PKC activation in the cytosol preparation. 6 ART induced the phosphorylation of p47phox, which was attenuated by GF 109203X. Moreover, ART evoked the membrane association of p47(phox), which was inhibited by GF 109203X and SB 203580. 7 These results indicate that the ART stimulation of superoxide anion generation involved the activation of p38 MAPK, PLC/Ca2

  17. 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.

  18. Probiotic-Derived Polyphosphate Enhances the Epithelial Barrier Function and Maintains Intestinal Homeostasis through Integrin–p38 MAPK Pathway

    PubMed Central

    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

  19. Vitamin A (retinol) downregulates the receptor for advanced glycation endproducts (RAGE) by oxidant-dependent activation of p38 MAPK and NF-kB in human lung cancer A549 cells.

    PubMed

    de Bittencourt Pasquali, Matheus Augusto; Gelain, Daniel Pens; Zeidán-Chuliá, Fares; Pires, André Simões; Gasparotto, Juciano; Terra, Silvia Resende; Moreira, José Cláudio Fonseca

    2013-04-01

    retinol is mediated by the redox-dependent activation of p38/NF-kB signaling pathway.

  20. Chk1 inhibition activates p53 through p38 MAPK in tetraploid cancer cells.

    PubMed

    Vitale, Ilio; Senovilla, Laura; Galluzzi, Lorenzo; Criollo, Alfredo; Vivet, Sonia; Castedo, Maria; Kroemer, Guido

    2008-07-01

    We have previously shown that tetraploid cancer cells succumb through a p53-dependent apoptotic pathway when checkpoint kinase 1 (Chk1) is depleted by small interfering RNAs (siRNAs) or inhibited with 7-hydroxystaurosporine (UCN-01). Here, we demonstrate that Chk1 inhibition results in the activating phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK). Depletion of p38 MAPK by transfection with a siRNA targeting the alpha isoform of p38 MAPK (p38alpha MAPK) abolishes the phosphorylation of p53 on serines 15 and 46 that is induced by Chk1 knockdown. The siRNA-mediated downregulation and pharmacological inhibition of p38alpha MAPK (with SB 203580) also reduces cell death induced by Chk1 knockdown or UCN-01. These results underscore the role of p38 MAPK as a pro-apoptotic kinase in the p53-dependant pathway for the therapeutic elimination of polyploidy cells.

  1. Coordination of Satellite Cell Activation and Self-Renewal by Par-Complex-Dependent Asymmetric Activation of p38α/β MAPK

    PubMed Central

    Troy, Andrew; Cadwallader, Adam B.; Fedorov, Yuri; Tyner, Kristina; Tanaka, Kathleen Kelly; Olwin, Bradley B.

    2014-01-01

    SUMMARY In response to muscle injury, satellite cells activate the p38α/β MAPK pathway to exit quiescence, then proliferate, repair skeletal muscle, and self-renew, replenishing the quiescent satellite cell pool. Although satellite cells are capable of asymmetric division, the mechanisms regulating satellite cell self-renewal are not understood. We found that satellite cells, once activated, enter the cell cycle and a subset undergoes asymmetric division, renewing the satellite cell pool. Asymmetric localization of the Par complex activates p38α/β MAPK in only one daughter cell, inducing MyoD, which permits cell cycle entry and generates a proliferating myoblast. The absence of p38α/β MAPK signaling in the other daughter cell prevents MyoD induction, renewing the quiescent satellite cell. Thus, satellite cells employ a mechanism to generate distinct daughter cells, coupling the Par complex and p38α/β MAPK signaling to link the response to muscle injury with satellite cell self-renewal. PMID:23040480

  2. p38 MAP kinase-dependent phosphorylation of the Gp78 E3 ubiquitin ligase controls ER-mitochondria association and mitochondria motility.

    PubMed

    Li, Lei; Gao, Guang; Shankar, Jay; Joshi, Bharat; Foster, Leonard J; Nabi, Ivan R

    2015-11-01

    Gp78 is an ERAD-associated E3 ubiquitin ligase that induces degradation of the mitofusin mitochondrial fusion proteins and mitochondrial fission. Gp78 is localized throughout the ER; however, the anti-Gp78 3F3A monoclonal antibody (mAb) recognizes Gp78 selectively in mitochondria-associated ER domains. Epitope mapping localized the epitope of 3F3A and a commercial anti-Gp78 mAb to an 8-amino acid motif (533-541) in mouse Gp78 isoform 2 that forms part of a highly conserved 41-amino acid region containing 14-3-3- and WW-binding domains and a p38 MAP kinase (p38 MAPK) consensus site on Ser-538 (S538). 3F3A binds selectively to nonphosphorylated S538 Gp78. Using 3F3A as a reporter, we induced Gp78 S538 phosphorylation by serum starvation and showed it to be mediated by p38 MAPK. Mass spectroscopy analysis of Gp78 phosphopeptides confirmed S538 as a major p38 MAPK phosphorylation site on Gp78. Gp78 S538 phosphorylation limited its ability to induce mitochondrial fission and degrade MFN1 and MFN2 but did not affect in vitro Gp78 ubiquitin E3 ligase activity. Phosphomimetic Gp78 S538D mutation prevented Gp78 promotion of ER-mitochondria interaction, and SB203580 inhibition of p38 MAPK increased ER-mitochondria association. p38 MAPK phosphorylation of Gp78 S538 therefore regulates Gp78-dependent ER-mitochondria association and mitochondria motility.

  3. Therapeutic effect of Rhizoma Dioscoreae Nipponicae on gouty arthritis based on the SDF-1/CXCR 4 and p38 MAPK pathway: an in vivo and in vitro study.

    PubMed

    Lu, Fang; Liu, Lei; Yu, Dong-hua; Li, Xu-zhao; Zhou, Qi; Liu, Shu-min

    2014-02-01

    Rhizoma Dioscoreae Nipponicae (RDN) is a widely used traditional Chinese herb, which is used to treat arthroncus, arthrodynia and arthritis. As is known to us, inflammatory mechanisms have played an important role in the occurrence, course and prognosis of gouty arthritis (GA). The aim of this study was to determine the characteristic expressed proteins of synovium in GA rat and synovial cell. The rat model of GA was induced by monosodium urate (MSU) crystal. Tissue samples were assayed by immunohistochemical method. The effects of RDN on Stromal cell-derived factor 1 (SDF-1), CXCR 4 and p38 mitogen-activated protein kinase (MAPK) were investigated in MSU crystal-induced rat. The levels of SDF-1 and mitogen-activated kinase kinase (MKK) 3/6 were measured by Western Blot in interleukin-1β (IL-1β) incubated fibroblast-like synoviocytes (FLS). A significant increase in the levels of SDF-1, CXCR 4 and p38 MAPK were observed in MSU crystal-induced rat. The increased SDF-1 and MKK 3/6 levels were observed in IL-1β incubated FLS. With the treatment of RDN, the above changes were reverted back to near normal levels. RDN might have some therapeutic effects on GA through SDF-1/CXCR 4 and p38 MAPK pathway, and dioscin may be the active compound in RDN to exert therapeutic effect on GA.

  4. Caenorhabditis elegans mom-4 is required for the activation of the p38 MAPK signaling pathway in the response to Pseudomonas aeruginosa infection.

    PubMed

    Xu, Ajing; Shi, Guojun; Liu, Feng; Ge, Baoxue

    2013-01-01

    The p38 mitogen-activated protein kinase (MAPK) plays an evolutionarily conserved role in the cellular response to microbial infection and environmental stress. Activation of p38 is mediated through phosphorylation by upstream MAPKK, which in turn is activated by MAPKKK. In the Caenorhabditis elegans, the p38 MAPK (also called PMK-1) signaling pathway has been shown to be required in its resistance to bacterial infection. However, how different upstream MAP2Ks and MAP3Ks specifically contribute to the activation of PMK-1 in response to bacterial infection still is not clearly understood. By using double-stranded RNA-mediated interference (RNAi) and genetic mutants of C. elegans, we demonstrate that C. elegans MOM-4, a mammalian TAK1 homolog, is required for the resistance of C. elegans to a P. aeruginosa infection. We have also found that the MKK-4 of C. elegans is required for P. aeruginosa resistance, but not through the regulation of DLK-1. In summary, our results indicate that different upstream MAPKKKs or MAPKKs regulate the activation of PMK-1 in response to P. Aeruginosa.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  7. CXCR1/2 ligands induce p38 MAPK-dependent translocation and release of opioid peptides from primary granules in vitro and in vivo.

    PubMed

    Rittner, Heike L; Labuz, Dominika; Richter, Jan F; Brack, Alexander; Schäfer, Michael; Stein, Christoph; Mousa, Shaaban A

    2007-11-01

    Polymorphonuclear leukocytes (PMN) can release opioid peptides which bind to opioid receptors on sensory neurons and inhibit inflammatory pain. This release can be triggered by chemokine receptor 1/2 (CXCR1/2) ligands. Our aim was to identify the granule subpopulation containing opioid peptides and to assess whether MAPK mediate the CXCR1/2 ligand-induced release of these peptides. Using double immunofluorescence confocal microscopy, we showed that beta-endorphin (END) and Met-enkephalin (ENK) were colocalized with the primary (azurophil) granule markers CD63 and myeloperoxidase (MPO) within PMN. END and ENK release triggered by a CXCR1/2 ligand in vitro was dependent on the presence of cytochalasin B (CyB) and on p38 MAPK, but not on p42/44 MAPK. In addition, translocation of END and ENK containing primary granules to submembranous regions of the cell was abolished by the p38 MAPK inhibitor SB203580. In vivo CXCL2/3 reduced pain in rats with complete Freund's adjuvant (CFA)-induced hindpaw inflammation. This effect was attenuated by intraplantar (i.pl.) antibodies against END and ENK and by i.pl. p38 MAPK inhibitor treatment. Taken together, these findings indicate that END and ENK are contained in primary granules of PMN, and that CXCR1/2 ligands induce p38-dependent translocation and release of these opioid peptides to inhibit inflammatory pain.

  8. 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.

  9. Lyn regulates inflammatory responses in Klebsiella pneumoniae infection via the p38/NF-κB pathway.

    PubMed

    Li, Xuefeng; Zhou, Xikun; Ye, Yan; Li, Yi; Li, Jiaxin; Privratsky, Breanna; Wu, Erxi; Gao, Hongwei; Huang, Canhua; Wu, Min

    2014-03-01

    Klebsiella pneumoniae (Kp) is one of the most common pathogens in nosocomial infections and is becoming increasingly multidrug resistant. However, the underlying molecular pathogenesis of this bacterium remains elusive, limiting the therapeutic options. Understanding the mechanism of its pathogenesis may facilitate the development of anti-bacterial therapeutics. Here, we show that Lyn, a pleiotropic Src tyrosine kinase, is involved in host defense against Kp by regulating phagocytosis process and simultaneously downregulating inflammatory responses. Using acute infection mouse models, we observed that lyn(-/-) mice were more susceptible to Kp with increased mortality and severe lung injury compared with WT mice. Kp infected-lyn(-/-) mice exhibited elevated inflammatory cytokines (IL-6 and TNF-α), and increased superoxide in the lung and other organs. In addition, the phosphorylation of p38 and NF-κB p65 subunit increased markedly in response to Kp infection in lyn(-/-) mice. We also demonstrated that the translocation of p65 from cytoplasm to nuclei increased in cultured murine lung epithelial cells by Lyn siRNA knockdown. Furthermore, lipid rafts clustered with activated Lyn and accumulated in the site of Kp invasion. Taken together, these findings revealed that Lyn may participate in host defense against Kp infection through the negative modulation of inflammatory cytokines.

  10. 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.

  11. 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

  12. Lipopolysaccharide regulates biosynthesis of cystathionine γ-lyase and hydrogen sulfide through Toll-like receptor-4/p38 and Toll-like receptor-4/NF-κB pathways in macrophages.

    PubMed

    Zheng, Yijie; Luo, Naixiang; Mu, Dongzhen; Jiang, Pei; Liu, Ronghua; Sun, Haozhe; Xiong, Shudao; Liu, Xiaoming; Wang, Luman; Chu, Yiwei

    2013-10-01

    Hydrogen sulfide (H2S), formed mainly by the enzyme cystathionine γ-lyase (CSE) in macrophages, is emerging as a novel regulator in inflammation. Although elevated production of H2S has been shown in inflammatory processes, the underlying molecular mechanism remains to be further elucidated. In this study, we compared parallel TLR4 knockout (TLR4(-/-)) mice with their wild-type counterparts following lipopolysaccharide (LPS) treatment. It showed that LPS increased the expressions of CSE and biosynthesis of H2S in C57BL/6 mice both in vivo and in vitro. However, the effects of LPS were not present in TLR4(-/-) mice, indicating the crucial role of TLR4 in LPS-induced expression of CSE and biosynthesis of H2S. We subsequently used JNK inhibitor, P38 inhibitor, and ERK inhibitor to block the downstream MAPK pathways of TLR4 in macrophages, and found that LPS-induced CSE expression and H2S synthesizing activity were inhibited by pretreatment with the p38 inhibitor. Similarly, the NF-κB inhibitor (BAY 11-7082) reversed the effects of LPS. These results suggest that LPS increases the biosynthesis of CSE and H2S in macrophages mainly in a TLR4-p38-dependent and TLR-4-NF-κB-dependent manner. These findings expand our knowledge of H2S biosynthesis during inflammation and provide a foundation for the development of novel H2S-based therapies.

  13. Helicobacter pylori promotes VEGF expression via the p38 MAPK‑mediated COX‑2‑PGE2 pathway in MKN45 cells.

    PubMed

    Liu, Ningning; Wu, Qiong; Wang, Yan; Sui, Hua; Liu, Xuan; Zhou, Ning; Zhou, Lihong; Wang, Yifei; Ye, Naijing; Fu, Xiaoling; Yu, Nikitin Alexander; Li, Qi

    2014-10-01

    Helicobacter pylori has been suggested to be the major cause of gastric malignancy. However, the pathogenesis and molecular mechanisms of gastric tumorigenesis induced by H. pylori infection are yet to be elucidated. In the present study, the expression levels of vascular endothelial growth factor (VEGF), which has been suggested to promote angiogenesis in gastric cancer, were found to be elevated in H. pylori-infected MKN45 cells. Furthermore, it was demonstrated that the expression of VEGF was modulated by the p38 mitogen-activated protein kinases (MAPK) pathway via regulation of the cyclooxygenase (COX)-2 pathway. It was also found that prostaglandin E2 (PGE2) and its receptor EP2/EP4 may mediate the upregulation of VEGF in gastric cells exposed to H. pylori. In combination, these results suggest that VEGF expression is regulated by the p38 MAPK COX‑2-PGE2-EP2/EP4 pathway in gastric cancer cells induced by H. pylori. This provides a theoretical basis for the investigation of the pathogenesis of H. pylori‑induced gastric cancer.

  14. Vitamin A (retinol) up-regulates the receptor for advanced glycation endproducts (RAGE) through p38 and Akt oxidant-dependent activation.

    PubMed

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

    2011-10-28

    Retinol (vitamin A) is believed to exert preventive/protective effects against malignant, neurodegenerative and cardiovascular diseases by acting as an antioxidant. However, later clinical and experimental data show a pro-oxidant action of retinol and other retinoids at specific conditions. The receptor for advanced glycation endproducts (RAGE) is a pattern recognition receptor, being activated by different ligands such as S100 proteins, HMGB1 (amphoterin), β-amyloid peptide and advanced glycation endproducts (AGE). RAGE activation influences a wide range of pathological conditions such as diabetes, pro-inflammatory states and neurodegenerative processes. Here, we investigated the involvement of different mitogen-activated protein kinases (MAPK: ERK1/2, p38 and JNK), PKC, PKA and Akt in the up-regulation of RAGE by retinol. As previously reported, we observed that the increase in RAGE immunocontent by retinol is reversed by antioxidant co-treatment, indicating the involvement of oxidative stress in this process. Furthermore, the p38 inhibitor SB203580 and the Akt inhibitor LY294002 also decreased the effect of retinol on RAGE levels, suggesting the involvement of these protein kinases in such effect. Both p38 and Akt phosphorylation were increased by treatment with pro-oxidant concentrations of retinol, and the antioxidant co-treatment blocked this effect, indicating that activation of p38 and Akt during retinol treatment is dependent on reactive species production. The 2',7'-dichlorohydrofluorescein diacetate (DCFH) assay also indicated that retinol treatment enhances cellular reactive species production. Altogether, these data indicate that RAGE up-regulation by retinol is mediated by the free radical-dependent activation of p38 and Akt.

  15. Andrographolide exerted its antimicrobial effects by upregulation of human β-defensin-2 induced through p38 MAPK and NF-κB pathway in human lung epithelial cells.

    PubMed

    Shao, Zhen-Jun; Zheng, Xiao-Wei; Feng, Ting; Huang, Juan; Chen, Jian; Wu, Yi-Ying; Zhou, Li-Ming; Tu, Wen-Wei; Li, Hong

    2012-05-01

    Andrographis paniculata (Burm. f) Nees is a traditional herbal medicine for the treatment of infection and inflammation in China. Andrographolide (andro) is one of the major components. Human β-defensin-2 (hBD-2) is an inducible antimicrobial peptide that plays an important role in innate immunity. The present study aimed to investigate the effect of andro on upregulation of hBD-2 and the key signaling pathways involved in andro-induced hBD-2 expression. Real-time reverse transcription - PCR and Western blot assays showed that andro (1.0-10 µmol/L) can upregulate the expression of hBD-2 in a dose-dependent manner. Further studies suggested that hBD-2 mRNA and protein expression in responsive to andro were attenuated by pretreatment with SB203580 (an inhibitor of p38 mitogen-activated protein kinase (p38 MAPK)), MG-132 (an inhibitor of nuclear factor κB (NF-κB)), and an NF-κB activator inhibitor, but not by an inhibitor of ERK (PD98059) or by an inhibitor of JNK(SP600125). Moreover, we found that a second p38 MAPK inhibitor (SB202190) significantly blocked andro-mediated hBD-2 induction in SPC-A-1 lung epithelial cells. Finally, the p-c-Jun transcription factor activity assay also showed that AP-1 activity was induced by andro compared with the untreated group. We conclude that andro may exert its antimicrobial effects by upregulating the expression of hBD-2 through the p38 MAPK and NF-κB pathway.

  16. 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.

  17. Jellyfish extract induces apoptotic cell death through the p38 pathway and cell cycle arrest in chronic myelogenous leukemia K562 cells

    PubMed Central

    Kwak, Choong-Hwan; Abekura, Fukushi; Park, Jun-Young; Park, Nam Gyu; Chang, Young-Chae; Lee, Young-Choon; Chung, Tae-Wook; Ha, Ki-Tae; Son, Jong-Keun

    2017-01-01

    Jellyfish species are widely distributed in the world’s oceans, and their population is rapidly increasing. Jellyfish extracts have several biological functions, such as cytotoxic, anti-microbial, and antioxidant activities in cells and organisms. However, the anti-cancer effect of Jellyfish extract has not yet been examined. We used chronic myelogenous leukemia K562 cells to evaluate the mechanisms of anti-cancer activity of hexane extracts from Nomura’s jellyfish in vitro. In this study, jellyfish are subjected to hexane extraction, and the extract is shown to have an anticancer effect on chronic myelogenous leukemia K562 cells. Interestingly, the present results show that jellyfish hexane extract (Jellyfish-HE) induces apoptosis in a dose- and time-dependent manner. To identify the mechanism(s) underlying Jellyfish-HE-induced apoptosis in K562 cells, we examined the effects of Jellyfish-HE on activation of caspase and mitogen-activated protein kinases (MAPKs), which are responsible for cell cycle progression. Induction of apoptosis by Jellyfish-HE occurred through the activation of caspases-3,-8 and -9 and phosphorylation of p38. Jellyfish-HE-induced apoptosis was blocked by a caspase inhibitor, Z-VAD. Moreover, during apoptosis in K562 cells, p38 MAPK was inhibited by pretreatment with SB203580, an inhibitor of p38. SB203580 blocked jellyfish-HE-induced apoptosis. Additionally, Jellyfish-HE markedly arrests the cell cycle in the G0/G1 phase. Therefore, taken together, the results imply that the anti-cancer activity of Jellyfish-HE may be mediated apoptosis by induction of caspases and activation of MAPK, especially phosphorylation of p38, and cell cycle arrest at the Go/G1 phase in K562 cells. PMID:28133573

  18. Cdc42 Promotes Schwann Cell Proliferation and Migration Through Wnt/β-Catenin and p38 MAPK Signaling Pathway After Sciatic Nerve Injury.

    PubMed

    Han, Bin; Zhao, Jun-Ying; Wang, Wu-Tao; Li, Zheng-Wei; He, Ai-Ping; Song, Xiao-Yang

    2017-01-17

    Schwann cells (SCs) are unique glial cells in the peripheral nerve and may secrete multiple neurotrophic factors, adhesion molecules, extracellular matrix molecules to form the microenvironment of peripheral nerve regeneration, guiding and supporting nerve proliferation and migration. Cdc42 plays an important regulatory role in dynamic changes of the cytoskeleton. However, there is a little study referred to regulation and mechanism of Cdc42 on glial cells after peripheral nerve injury. The present study investigated the role of Cdc42 in the proliferation and migration of SCs after sciatic nerve injury. Cdc42 expression was tested, showing that the mRNA and protein expression levels of Cdc42 were significantly up-regulated after sciatic nerve injury. Then, we isolated and purified SCs from injuried sciatic nerve at day 7. The purified SCs were transfected with Cdc42 siRNA and pcDNA3.1-Cdc42, and the cell proliferation, cell cycle and migration were assessed. The results implied that Cdc42 siRNA remarkably inhibited Schwann cell proliferation and migration, and resulted in S phase arrest. While pcDNA3.1-Cdc42 showed a contrary effect. Besides, we also observed that Cdc42 siRNA down-regulated the protein expression of β-catenin, Cyclin D1, c-myc and p-p38, which were up-regulated by pcDNA3.1-Cdc42. Meanwhile, the inhibitor of Wnt/β-catenin and p38 MAPK signaling pathway IWP-2 and SB203580 significantly inhibited the effect of pcDNA3.1-Cdc42 on cell proliferation and migration. Overall, our data indicate that Cdc42 regulates Schwann cell proliferation and migration through Wnt/β-catenin and p38 MAPK signaling pathway after sciatic nerve injury, which provides further insights into the therapy of the sciatic nerve injury.

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

    PubMed

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

    2015-11-01

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

  20. Soluble Receptor for Advanced Glycation End Product Ameliorates Chronic Intermittent Hypoxia Induced Renal Injury, Inflammation, and Apoptosis via P38/JNK Signaling Pathways

    PubMed Central

    Wu, Xu; Gu, Wenyu; Lu, Huan; Liu, Chengying; Yu, Biyun; Xu, Hui; Tang, Yaodong

    2016-01-01

    Obstructive sleep apnea (OSA) associated chronic kidney disease is mainly caused by chronic intermittent hypoxia (CIH) triggered tissue damage. Receptor for advanced glycation end product (RAGE) and its ligand high mobility group box 1 (HMGB1) are expressed on renal cells and mediate inflammatory responses in OSA-related diseases. To determine their roles in CIH-induced renal injury, soluble RAGE (sRAGE), the RAGE neutralizing antibody, was intravenously administered in a CIH model. We also evaluated the effect of sRAGE on inflammation and apoptosis. Rats were divided into four groups: (1) normal air (NA), (2) CIH, (3) CIH+sRAGE, and (4) NA+sRAGE. Our results showed that CIH accelerated renal histological injury and upregulated RAGE-HMGB1 levels involving inflammatory (NF-κB, TNF-α, and IL-6), apoptotic (Bcl-2/Bax), and mitogen-activated protein kinases (phosphorylation of P38, ERK, and JNK) signal transduction pathways, which were abolished by sRAGE but p-ERK. Furthermore, sRAGE ameliorated renal dysfunction by attenuating tubular endothelial apoptosis determined by immunofluorescence staining of CD31 and TUNEL. These findings suggested that RAGE-HMGB1 activated chronic inflammatory transduction cascades that contributed to the pathogenesis of the CIH-induced renal injury. Inhibition of RAGE ligand interaction by sRAGE provided a therapeutic potential for CIH-induced renal injury, inflammation, and apoptosis through P38 and JNK pathways. PMID:27688824

  1. NFATC1 promotes cell growth and tumorigenesis in ovarian cancer up-regulating c-Myc through ERK1/2/p38 MAPK signal pathway.

    PubMed

    Xu, Wenwen; Gu, Junjie; Ren, Qingling; Shi, Yanqiu; Xia, Qinhua; Wang, Jing; Wang, Suli; Wang, Yingchun; Wang, Jinhua

    2016-04-01

    It has been reported that nuclear factor of activated T cells (NFATC1) was up-regulated in cancers mediating malignant behaviors. However, the role of NFATC1 in ovarian cancer has not been elucidated. In the present study, we undertook to explore the clinicopathological significance of NFATC1 expression and the mechanism by which NFATC1 works in ovarian cancer. Expression status of NFATC1 was examined using immunohistochemistry. Both knockdown and re-expression of NFATC1 on ovarian cancer cells were employed to observe the effect overgrowth. It was found that NFATC1 was significantly overexpressed in ovarian cancer tissues in comparison with paired normal control tissues and that overexpression of NFATC1 was significantly associated with metastasis and poor prognosis on clinical tissue level. In in vitro ovarian cancer cell lines, we found that NFATC1 can promote proliferation up-regulating c-myc through activation of ERK1/2/p38/MAPK signal pathway. Together, the results we obtained demonstrated that NFATC1 played oncogenic role in ovarian cancer. Mechanistically, NFATC1 promoted growth of ovarian cancer cells up-regulating c-myc through activation of ERK1/2/p38/MAPK signal pathway, suggesting that NFATC1 might be used as a therapeutic target for ovarian cancer.

  2. The problem of pyridinyl imidazole class inhibitors of MAPK14/p38α and MAPK11/p38β in autophagy research.

    PubMed

    Menon, Manoj B; Dhamija, Sonam; Kotlyarov, Alexey; Gaestel, Matthias

    2015-01-01

    In addition to its established role in inflammation, the stress-activated p38 MAP kinase pathway plays major roles in the regulation of cell cycle, senescence, and autophagy. Robust studies could establish mechanistic links between MAPK11-MAPK14/p38 signaling and macroautophagy converging at ATG9-trafficking and BECN1 phosphorylation. However, several reports seem to monitor MAPK11-MAPK14/p38-dependence of autophagy exclusively by the use of the SB203580/SB202190 class of MAPK14/MAPK11/p38α/β inhibitors. In this "Letter to the editor" we present data to support our claim that these inhibitors interfere with autophagic flux in a MAPK11-MAPK14/p38-independent manner and hence should no longer be used as pharmacological tools in the analysis of MAPK11-MAPK14/p38-dependence of autophagy. We propose a general guideline from Autophagy with regard to this issue to avoid such misinterpretations in the future.

  3. Butein induction of HO-1 by p38 MAPK/Nrf2 pathway in adipocytes attenuates high-fat diet induced adipose hypertrophy in mice.

    PubMed

    Wang, Zheng; Ka, Sun-O; Lee, Youngyi; Park, Byung-Hyun; Bae, Eun Ju

    2017-03-15

    Adipose tissue inflammation and oxidative stress are key components in the development of obesity and insulin resistance. Heme oxygenase (HO)-1 in adipocytes protects against obesity and adipose dysfunction. In this study, we report the identification of butein, a flavonoid chalcone, as a novel inducer of HO-1 expression in adipocytes in vitro and in vivo. Butein upregulated HO-1 mRNA and protein expression in 3T3-L1 adipocytes, accompanied by Kelch-Like ECH-Associated Protein (Keap) 1 degradation and increase in the nuclear level of nuclear factor erythroid 2-related factor 2 (Nrf2). Butein modulation of Keap1 and Nrf2 as well as HO-1 upregulation was reversed by pretreatment with p38 MAPK inhibitor SB203580, indicating the involvement of p38 MAPK in butein activation of Nrf2 in adipocytes. In addition, HO-1 activation by butein led to the inhibitions of reactive oxygen species and adipocyte differentiation, as evidenced by the fact that butein repression of reactive oxygen species and adipogenesis was reversed by pretreatment with HO-1 inhibitor SnPP. Induction of HO-1 expression by butein was also demonstrated in the adipose tissue of C57BL/6 mice fed a high-fat diet administered along with butein for three weeks, and correlated with the inhibitions of adiposity and adipose tissue inflammation, which were reversed by co-administration of SnPP. Altogether, our results demonstrate that butein activates the p38 MAPK/Nrf2/HO-1 pathway to act as a potent inhibitor of adipose hypertrophy and inflammation in a diet-induced obesity model and thus has potential for suppressing obesity-linked metabolic syndrome.

  4. ICAM-1-induced expression of proinflammatory cytokines in astrocytes: involvement of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase pathways.

    PubMed

    Lee, S J; Drabik, K; Van Wagoner, N J; Lee, S; Choi, C; Dong, Y; Benveniste, E N

    2000-10-15

    ICAM-1 is a transmembrane glycoprotein of the Ig superfamily involved in cell adhesion. ICAM-1 is aberrantly expressed by astrocytes in CNS pathologies such as multiple sclerosis, experimental allergic encephalomyelitis, and Alzheimer's disease, suggesting a possible role for ICAM-1 in these disorders. ICAM-1 has been shown to be important for leukocyte diapedesis through brain microvessels and subsequent binding to astrocytes. However, other functional roles for ICAM-1 expression on astrocytes have not been well elucidated. Therefore, we investigated the intracellular signals generated upon ICAM-1 engagement on astrocytes. ICAM-1 ligation by a mAb to rat ICAM-1 induced mRNA expression of proinflammatory cytokines such as IL-1alpha, IL-1beta, IL-6, and TNF-alpha. Examination of cytokine protein production revealed that ICAM-1 ligation results in IL-6 secretion by astrocytes, whereas IL-1beta and IL-1alpha protein is expressed intracellularly in astrocytes. The involvement of mitogen-activated protein kinases (MAPKs) in ICAM-1-mediated cytokine expression in astrocytes was tested, as the MAPK extracellular signal-regulated kinase (ERK) was previously shown to be activated upon ICAM-1 engagement. Our results indicate that ERK1/ERK2, as well as p38 MAPK, are activated upon ligation of ICAM-1. Studies using pharmacological inhibitors demonstrate that both p38 MAPK and ERK1/2 are involved in ICAM-1-induced IL-6 expression, whereas only ERK1/2 is important for IL-1alpha and IL-1beta expression. Our data support the role of ICAM-1 on astrocytes as an inflammatory mediator in the CNS and also uncover a novel signal transduction pathway through p38 MAPK upon ICAM-1 ligation.

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

    PubMed Central

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

    2016-01-01

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

  6. P2Y12 receptor-mediated activation of spinal microglia and p38MAPK pathway contribute to cancer-induced bone pain

    PubMed Central

    Liu, Mingjuan; Yao, Ming; Wang, Hanqi; Xu, Longsheng; Zheng, Ying; Huang, Bing; Ni, Huadong; Xu, Shijie; Zhou, Xuyan; Lian, Qingquan

    2017-01-01

    Background Cancer-induced bone pain (CIBP) is one of the most challenging clinical problems due to a lack of understanding the mechanisms. Recent evidence has demonstrated that activation of microglial G-protein-coupled P2Y12 receptor (P2Y12R) and proinflammatory cytokine production play an important role in neuropathic pain generation and maintenance. However, whether P2Y12R is involved in CIBP remains unknown. Methods The purpose of this study was to investigate the role of P2Y12R in CIBP and its molecular mechanisms. Using the bone cancer model inoculated with Walker 256 tumor cells into the left tibia of Sprague Dawley rat, we blocked spinal P2Y12R through intrathecal administration of its selective antagonist MRS2395 (400 pmol/µL, 15 µL). Results We found that not only the ionized calcium-binding adapter molecule 1 (Iba-1)-positive microglia in the ipsilateral spinal cord but also mechanical allodynia was significantly inhibited. Furthermore, it decreased the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) and the production of proinflammatory cytokines interleukin-1β (IL-1β) and interleukin-6 (IL-6), whereas it increased tumor necrosis factor-α (TNF-α). Conclusion Taken together, our present results suggest that microglial P2Y12R in the spinal cord may contribute to CIBP by the activation of spinal microglia and p38MAPK pathway, thus identifying a potential therapeutic target for the treatment of CIBP. PMID:28243146

  7. LPS-induced iNOS expression in N9 microglial cells is suppressed by geniposide via ERK, p38 and nuclear factor-κB signaling pathways.

    PubMed

    Zhang, Gu; He, Jun-Lin; Xie, Xiao-Yan; Yu, Chao

    2012-09-01

    Activated microglia producing reactive nitrogen species, inflammatory factors, reactive oxygen species (ROS) and other neurovirulent factors, can lead to the development of neurodegenerative diseases. Certain compounds can inhibit the activation of microglia. However, the mechanisms remain unclear. In the present study, we investigated the inhibitory effect of geniposide on the production of ROS and inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-stimulated N9 murine microglial cells through the p38, ERK1/2 and nuclear factor-κB (NF-κB) signaling pathways. After the N9 cells were pre-treated with the vehicle or geniposide and exposed to LPS for the time indicated, the MTT conversion test was used to assess cell viability. Suitable concentrations were chosen and adjusted according to the experiments. Extracellular nitric oxide (NO) release was measured by Griess reaction. The formation of ROS and intracellular NO was evaluated by fluorescence imaging. NOS activities were determined using commercially available kits. The morphology of the N9 cells was examined by hematoxylin and eosin staining. The expression of iNOS mRNA was examined by RT-PCR. The protein levels of iNOS, p38 mitogen-activated protein kinase (MAPK), ERK1/2 and NF-κB, inhibitory factor-κB-α (IκB-α) were determined by western blot analysis. The results showed that geniposide attenuated the activation of N9 cells and inhibited the overproduction of NO, intracellular ROS and the expression of iNOS induced by LPS in the cells. In addition, geniposide blocked the phosphorylation of p38, ERK1/2 and inhibited the drop-off of IκB induced by LPS in the cells. These data indicate that geniposide has therapeutic potential for the treatment of neurodegenerative diseases, and that it exerts its effects by inhibiting inflammation.

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

    PubMed Central

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

    2016-01-01

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

  9. 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

    2016-03-10

    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.

  10. IL-1α Expression in Pancreatic Ductal Adenocarcinoma Affects the Tumor Cell Migration and Is Regulated by the p38MAPK Signaling Pathway

    PubMed Central

    Tjomsland, Vegard; Bojmar, Linda; Sandström, Per; Bratthäll, Charlotte; Messmer, Davorka; Spångeus, Anna; Larsson, Marie

    2013-01-01

    The interplay between the tumor cells and the surrounding stroma creates inflammation, which promotes tumor growth and spread. The inflammation is a hallmark for pancreatic adenocarcinoma (PDAC) and is to high extent driven by IL-1α. IL-1α is expressed and secreted by the tumor cells and exerting its effect on the stroma, i.e. cancer associated fibroblasts (CAF), which in turn produce massive amount of inflammatory and immune regulatory factors. IL-1 induces activation of transcription factors such as nuclear factor-κβ (NF-κβ), but also activator protein 1 (AP-1) via the small G-protein Ras. Dysregulation of Ras pathways are common in cancer as this oncogene is the most frequently mutated in many cancers. In contrast, the signaling events leading up to the expression of IL-1α by tumor cells are not well elucidated. Our aim was to examine the signaling cascade involved in the induction of IL-1α expression in PDAC. We found p38MAPK, activated by the K-Ras signaling pathway, to be involved in the expression of IL-1α by PDAC as blocking this pathway decreased both the gene and protein expression of IL-1α. Blockage of the P38MAPK signaling in PDAC also dampened the ability of the tumor cell to induce inflammation in CAFs. In addition, the IL-1α autocrine signaling regulated the migratory capacity of PDAC cells. Taken together, the blockage of signaling pathways leading to IL-1α expression and/or neutralization of IL-1α in the PDAC microenvironment should be taken into consideration as possible treatment or complement to existing treatment of this cancer. PMID:23951028

  11. Aconitine-induced Ca{sup 2+} overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

    SciTech Connect

    Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao; Hu, Jin; Zhang, Qiang; Liu, Bo; Wang, Min; Xu, Hui-bo; Sun, Xiao-bo

    2014-08-15

    Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na{sup +} channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca{sup 2+} in aconitine poisoning. In this study, we explored the importance of pathological Ca{sup 2+} signaling in aconitine poisoning in vitro and in vivo. We found that Ca{sup 2+} overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca{sup 2+} handling proteins demonstrated that aconitine promoted Ca{sup 2+} overload through the expression regulation of Ca{sup 2+} handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca{sup 2+} overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca

  12. Differential roles of MAPK-Erk1/2 and MAPK-p38 in insulin or insulin-like growth factor-I (IGF-I) signaling pathways for progesterone production in human ovarian cells.

    PubMed

    Seto-Young, D; Avtanski, D; Varadinova, M; Park, A; Suwandhi, P; Leiser, A; Parikh, G; Poretsky, L

    2011-06-01

    Insulin and insulin like-growth factor-I (IGF-I) participate in the regulation of ovarian steroidogenesis. In insulin resistant states ovaries remain sensitive to insulin because insulin can activate alternative signaling pathways, such as phosphatidylinositol-3-kinase (PI-3 kinase) and mitogen-activated protein-kinase (MAPK) pathways, as well as insulin receptors and type 1 IGF receptors. We investigated the roles of MAPK-Erk1/2 and MAPK-p38 in insulin and IGF-I signaling pathways for progesterone production in human ovarian cells. Human ovarian cells were cultured in tissue culture medium in the presence of varying concentrations of insulin or IGF-I, with or without PD98059, a specific MAPK-Erk1/2 inhibitor, with or without SB203580, a specific MAPK-p38 inhibitor or with or without a specific PI-3-kinase inhibitor LY294002. Progesterone concentrations were measured using radioimmunoassay. PD98059 alone stimulated progesterone production in a dose-dependent manner by up to 65% (p<0.001). Similarly, LY294002 alone stimulated progesterone production by 13-18% (p<0.005). However, when used together, PD98059 and LY294002 inhibited progesterone production by 17-20% (p<0.001). SB203580 alone inhibited progesterone production by 20-30% (p<0.001). Insulin or IGF-I alone stimulated progesterone production by 40-60% (p<0.001). In insulin studies, PD98059 had no significant effect on progesterone synthesis while SB203580 abolished insulin-induced progesterone production. Either PD98059 or SB203580 abolished IGF-I-induced progesterone production. Both MAPK-Erk1/2 and MAPK-p38 participate in IGF-I-induced signaling pathways for progesterone production, while insulin-induced progesterone production requires MAPK-p38, but not MAPK-Erk1/2. These studies provide further evidence for divergence of insulin and IGF-I signaling pathways for human ovarian cell steroidogenesis.

  13. Knockdown of the MAPK p38 pathway increases the susceptibility of Chilo suppressalis larvae to Bacillus thuringiensis Cry1Ca toxin

    PubMed Central

    Qiu, Lin; Fan, Jinxing; Liu, Lang; Zhang, Boyao; Wang, Xiaoping; Lei, Chaoliang; Lin, Yongjun; Ma, Weihua

    2017-01-01

    The bacterium Bacillus thuringiensis (Bt) produces a wide range of toxins that are effective against a number of insect pests. Identifying the mechanisms responsible for resistance to Bt toxin will improve both our ability to control important insect pests and our understanding of bacterial toxicology. In this study, we investigated the role of MAPK pathways in resistance against Cry1Ca toxin in Chilo suppressalis, an important lepidopteran pest of rice crops. We first cloned the full-length of C. suppressalis mitogen-activated protein kinase (MAPK) p38, ERK1, and ERK2, and a partial sequence of JNK (hereafter Csp38, CsERK1, CsERK2 and CsJNK). We could then measure the up-regulation of these MAPK genes in larvae at different times after ingestion of Cry1Ca toxin. Using RNA interference to knockdown Csp38, CsJNK, CsERK1 and CsERK2 showed that only knockdown of Csp38 significantly increased the mortality of larvae to Cry1Ca toxin ingested in either an artificial diet, or after feeding on transgenic rice expressed Cry1Ca. These results suggest that MAPK p38 is responsible for the resistance of C. suppressalis larvae to Bt Cry1Ca toxin. PMID:28262736

  14. Puerarin protects mouse liver against nickel-induced oxidative stress and inflammation associated with the TLR4/p38/CREB pathway.

    PubMed

    Liu, Chan-Min; Ma, Jie-Qiong; Liu, Si-Si; Feng, Zhao-Jun; Wang, Ai-Min

    2016-01-05

    Nickel (Ni), one of hazardous environmental chemicals, is known to cause liver injury. Accumulating evidence showed that puerarin (PU) possessed comprehensive biological effects. The purpose of the current study was to test the hypothesis that the puerarin protects against enhanced liver injury caused by Ni in mice. ICR mice received intraperitoneally nickel sulfate (20 mg/kg/body weight, daily) for 20 days, and puerarin (200 and 400 mg/kg/body weight) was applied before Ni exposure. The results indicated that puerarin markedly inhibited Ni-induced liver injury, which was characterized by decreased aminotransferase activities and inflammation. Puerarin also inhibited the oxidative stress and decreased the metallothionein (MT) levels. Puerarin decreased the level of pro-inflammatory cytokines TNF-α and IL-6 in livers. Puerarin significantly inhibited the TLR4 activation and p38 MAPK phosphorylation, which in turn inhibited NF-κB activity. Likewise, Ni-induced inflammatory responses were diminished by puerarin as observed by a remarkable reduction in the levels of phosphorylated CREB. Furthermore, puerarin also reduced inflammatory mediators such as cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) levels in livers. Data from this study suggested that the inhibition of Ni-induced oxidative stress and inflammatory responses by puerarin is due to its ability to modulate the TLR4/p38/CREB signaling pathway.

  15. Binding of FGF2 to FGFR2 in an autocrine mode in trophectoderm cells is indispensable for mouse blastocyst formation through PKC-p38 pathway

    PubMed Central

    Yang, Jing; Zhang, Dan; Yu, Ying; Zhang, Run-Ju; Hu, Xiao-Ling; Huang, He-Feng; Lu, Yong-Chao

    2015-01-01

    Fibroblast growth factors (FGF1, FGF2 and FGF4) and fibroblast growth factor receptors (FGFR1, FGFR2, FGFR3 and FGFR4) have been reported to be expressed in preimplantation embryos and be required for their development. However, the functions of these molecules in trophectoderm cells (TEs) that lead to the formation of the blastocyst as well as the underlying mechanism have not been elucidated. The present study has demonstrated for the first time that endogenous FGF2 secreted by TEs can regulate protein expression and distribution in TEs via the FGFR2-mediated activation of PKC and p38, which are important for the development of expanded blastocysts. This finding provides the first explanation for the long-observed phenomenon that only high concentrations of exogenous FGFs have effects on embryonic development, but in vivo the amount of endogenous FGFs are trace. Besides, the present results suggest that FGF2/FGFR2 may act in an autocrine fashion and activate the downstream PKC/p38 pathway in TEs during expanded blastocyst formation. PMID:26378412

  16. The NF2 Tumor Suppressor Regulates Microtubule-Based Vesicle Trafficking via a Novel Rac, MLK and p38SAPK Pathway

    PubMed Central

    Hennigan, Robert F.; Moon, Chandra A.; Parysek, Linda M.; Monk, Kelly R.; Morfini, Gerardo; Berth, Sarah; Brady, Scott; Ratner, Nancy

    2014-01-01

    Neurofibromatosis Type 2 patients develop schwannomas, meningiomas and ependymomas resulting from mutations in the tumor suppressor gene, NF2, encoding a membrane-cytoskeleton adaptor protein called merlin. Merlin regulates contact inhibition of growth and controls the availability of growth factor receptors at the cell surface. We tested if microtubule-based vesicular trafficking might be a mechanism by which merlin acts. We found that schwannoma cells, containing merlin mutations and constitutive activation of the Rho/Rac family of GTPases, had decreased intracellular vesicular trafficking relative to normal human Schwann cells. In Nf2−/− mouse Schwann (SC4) cells, re-expression of merlin as well as inhibition of Rac or its effector kinases, MLK and p38SAPK, each increased the velocity of Rab6 positive exocytic vesicles. Conversely, an activated Rac mutant decreased Rab6 vesicle velocity. Vesicle motility assays in isolated squid axoplasm further demonstrated that both mutant merlin and active Rac specifically reduce anterograde microtubule-based transport of vesicles dependent upon the activity of p38SAPK kinase. Taken together, our data suggest loss of merlin results in the Rac dependent decrease of anterograde trafficking of exocytic vesicles, representing a possible mechanism controlling the concentration of growth factor receptors at the cell surface. PMID:22525268

  17. Targeting cancer cell metabolism: The combination of metformin and 2-Deoxyglucose regulates apoptosis in ovarian cancer cells via p38 MAPK/JNK signaling pathway

    PubMed Central

    Zhu, Jie; Zheng, Ya; Zhang, Haiyan; Sun, Hong

    2016-01-01

    Targeting cancer cell metabolism is a new promising strategy to fight cancer. Metformin, a first-line treatment for type 2 diabetes mellitus, exerts anti-cancer and anti-proliferative action. 2-deoxyglucose (2-DG), a glucose analog, works as a competitive inhibitor of glycolysis. In this study, we show for the first time that metformin in combination with 2-DG inhibited growth, migration, invasion and induced cell cycle arrest of ovarian cancer cells in vitro. Moreover, metformin and 2-DG could efficiently induce apoptosis in ovarian cancer cells, which was achieved by activating p38 MAPK and JNK pathways. Our study reinforces the growing interest of metabolic interference in cancer therapy and highlights the potential use of the combination of metformin and 2-DG as an anti-tumor treatment in ovarian cancer. PMID:27904682

  18. Attenuation of RANKL-induced Osteoclast Formation via p38-mediated NFATc1 Signaling Pathways by Extract of Euphorbia Lathyris L

    PubMed Central

    Kang, Ju-Hee; Lim, Hyojung; Jeong, Ji-Eun

    2016-01-01

    Background Osteoclasts are the only cell type capable of breaking down bone matrix, and its excessive activation is responsible for the development of bone-destructive diseases. Euphorbia lathyris L. (ELL) is an herbal plant that belongs to the Euphorbiaceae family. This study investigated the effects of the methanol extract of the aerial part of ELL on receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclast formation and signaling pathways. Methods Osteoclasts were formed by co-culturing mouse bone marrow with osteoblasts or by culturing mouse bone marrow-derived macrophages (BMMs) with macrophage colony-stimulating factor (M-CSF) and RANKL. Bone resorption assays were performed using dentine slices. The expression level of mRNA was analyzed by real-time polymerase chain reaction (PCR) or reverse transcription (RT)-PCR. Western blotting assays were performed to detect the expression or activation level of proteins. Results ELL inhibited RANKL-induced osteoclast formation without cytotoxicity. Furthermore, the RANKL-stimulated bone resorption was diminished by ELL. Mechanistically, ELL blocked the RANKL-triggered p38 mitogen-activated protein kinase (MAPK) phosphorylation, which resulted in the suppression of the expression of c-Fos and nuclear factor of activated T cells (NFATc1). In osteoblasts, ELL had little effect on the mRNA expression of RANKL and osteoprotegerin (OPG). Conclusions The present data suggest that ELL has an inhibitory effect on osteoclast differentiation and function via downregulation of the p38/c-Fos/NFATc1 signaling pathways. Thus, ELL could be useful for the treatment of bone diseases associated with excessive bone resorption. PMID:27965942

  19. The ROS-mediated pathway coupled with the MAPK-p38 signalling pathway and antioxidant system plays roles in the responses of Mytilus edulis haemocytes induced by BDE-47.

    PubMed

    Jiang, Yongshun; Tang, Xuexi; Zhou, Bin; Sun, Tianli; Chen, Hongmei; Zhao, Xinyu; Wang, You

    2017-03-18

    Our previous study found that BDE-47 could change the immune function of haemocytes in Mytilus edulis, and reactive oxygen species (ROS) might be involved in the process of physiological alteration. Here, we aimed to better understand this relationship. To accomplish this, we analysed changes in different ROS as well as various antioxidant system components. Additionally, the expression of MAPK-p38, a signalling protein regulated by ROS that helps to regulate numerous cellular processes, was also analysed. BDE-47 was given at low, medium, and high amounts. The results showed that (1) BDE-47 significantly affected ROS component levels in haemocytes. O2(-) content was increased under all conditions. H2O2 content was also increased under all conditions, except in the middle concentration group. In contrast, OH content was increased in the low and middle concentration groups and decreased in the high concentration group. (2) Estimations of the antioxidant systems revealed concentration-dependent changes. Catalase activity was increased throughout the experiment, while superoxide dismutase (SOD) exhibited a decreasing trend in the tested groups with an increase of exposure time. On day 21, only the high concentration group showed a slight increase in SOD activity compared to the control. Furthermore, glutathione peroxidase and glutathione reductase activity increased in the low and middle concentration groups but decreased in the high concentration group. The GSH/GSSG ratio increased for all treatments over time, indicating that changes in redox status occurred. (3) MAPK-p38 was activated following BDE-47 exposure. Based on our previous study, we speculate that BDE-47 exposure induces ROS production and affects the ROS-mediated pathway, which may explain the resultant functional damage observed in haemocytes. Furthermore, BDE-47 also affected the antioxidant system and altered redox status, although these changes did not ameliorate the damage caused by ROS.

  20. Zinc rescues obesity-induced cardiac hypertrophy via stimulating metallothionein to suppress oxidative stress-activated BCL10/CARD9/p38 MAPK pathway.

    PubMed

    Wang, Shudong; Gu, Junlian; Xu, Zheng; Zhang, Zhiguo; Bai, Tao; Xu, Jianxiang; Cai, Jun; Barnes, Gregory; Liu, Qiu-Ju; Freedman, Jonathan H; Wang, Yonggang; Liu, Quan; Zheng, Yang; Cai, Lu

    2017-02-03

    Obesity often leads to obesity-related cardiac hypertrophy (ORCH), which is suppressed by zinc-induced inactivation of p38 mitogen-activated protein kinase (p38 MAPK). In this study, we investigated the mechanisms by which zinc inactivates p38 MAPK to prevent ORCH. Mice (4-week old) were fed either high fat diet (HFD, 60% kcal fat) or normal diet (ND, 10% kcal fat) containing variable amounts of zinc (deficiency, normal and supplement) for 3 and 6 months. P38 MAPK siRNA and the p38 MAPK inhibitor SB203580 were used to suppress p38 MAPK activity in vitro and in vivo, respectively. HFD activated p38 MAPK and increased expression of B-cell lymphoma/CLL 10 (BCL10) and caspase recruitment domain family member 9 (CARD9). These responses were enhanced by zinc deficiency and attenuated by zinc supplement. Administration of SB203580 to HFD mice or specific siRNA in palmitate-treated cardiomyocytes eliminated the HFD and zinc deficiency activation of p38 MAPK, but did not significantly impact the expression of BCL10 and CARD9. In cultured cardiomyocytes, inhibition of BCL10 expression by siRNA prevented palmitate-induced increased p38 MAPK activation and atrial natriuretic peptide (ANP) expression. In contrast, inhibition of p38 MAPK prevented ANP expression, but did not affect BCL10 expression. Deletion of metallothionein abolished the protective effect of zinc on palmitate-induced up-regulation of BCL10 and phospho-p38 MAPK. HFD and zinc deficiency synergistically induce ORCH by increasing oxidative stress-mediated activation of BCL10/CARD9/p38 MAPK signalling. Zinc supplement ameliorates ORCH through activation of metallothionein to repress oxidative stress-activated BCL10 expression and p38 MAPK activation.

  1. The investigational Aurora kinase A inhibitor alisertib (MLN8237) induces cell cycle G2/M arrest, apoptosis, and autophagy via p38 MAPK and Akt/mTOR signaling pathways in human breast cancer cells

    PubMed Central

    Li, Jin-Ping; Yang, Yin-Xue; Liu, Qi-Lun; Pan, Shu-Ting; He, Zhi-Xu; Zhang, Xueji; Yang, Tianxin; Chen, Xiao-Wu; Wang, Dong; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Alisertib (ALS) is an investigational potent Aurora A kinase inhibitor currently undergoing clinical trials for the treatment of hematological and non-hematological malignancies. However, its antitumor activity has not been tested in human breast cancer. This study aimed to investigate the effect of ALS on the growth, apoptosis, and autophagy, and the underlying mechanisms in human breast cancer MCF7 and MDA-MB-231 cells. In the current study, we identified that ALS had potent growth-inhibitory, pro-apoptotic, and pro-autophagic effects in MCF7 and MDA-MB-231 cells. ALS arrested the cells in G2/M phase in MCF7 and MDA-MB-231 cells which was accompanied by the downregulation of cyclin-dependent kinase (CDK)1/cell division cycle (CDC) 2, CDK2, and cyclin B1 and upregulation of p21 Waf1/Cip1, p27 Kip1, and p53, suggesting that ALS induces G2/M arrest through modulation of p53/p21/CDC2/cyclin B1 pathways. ALS induced mitochondria-mediated apoptosis in MCF7 and MDA-MB-231 cells; ALS significantly decreased the expression of B-cell lymphoma 2 (Bcl-2), but increased the expression of B-cell lymphoma 2-associated X protein (Bax) and p53-upregulated modulator of apoptosis (PUMA), and increased the expression of cleaved caspases 3 and 9. ALS significantly increased the expression level of membrane-bound microtubule-associated protein 1 light chain 3 (LC3)-II and beclin 1 and induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase (MAPK) pathways in MCF7 and MDA-MB-231 cells as indicated by their altered phosphorylation, contributing to the pro-autophagic activities of ALS. Furthermore, treatment with wortmannin markedly downregulated ALS-induced p38 MAPK activation and LC3 conversion. In addition, knockdown of the p38 MAPK gene by ribonucleic acid interference upregulated Akt activation and resulted in LC3-II accumulation. These findings indicate that ALS promotes cellular

  2. The investigational Aurora kinase A inhibitor alisertib (MLN8237) induces cell cycle G2/M arrest, apoptosis, and autophagy via p38 MAPK and Akt/mTOR signaling pathways in human breast cancer cells.

    PubMed

    Li, Jin-Ping; Yang, Yin-Xue; Liu, Qi-Lun; Pan, Shu-Ting; He, Zhi-Xu; Zhang, Xueji; Yang, Tianxin; Chen, Xiao-Wu; Wang, Dong; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Alisertib (ALS) is an investigational potent Aurora A kinase inhibitor currently undergoing clinical trials for the treatment of hematological and non-hematological malignancies. However, its antitumor activity has not been tested in human breast cancer. This study aimed to investigate the effect of ALS on the growth, apoptosis, and autophagy, and the underlying mechanisms in human breast cancer MCF7 and MDA-MB-231 cells. In the current study, we identified that ALS had potent growth-inhibitory, pro-apoptotic, and pro-autophagic effects in MCF7 and MDA-MB-231 cells. ALS arrested the cells in G2/M phase in MCF7 and MDA-MB-231 cells which was accompanied by the downregulation of cyclin-dependent kinase (CDK)1/cell division cycle (CDC) 2, CDK2, and cyclin B1 and upregulation of p21 Waf1/Cip1, p27 Kip1, and p53, suggesting that ALS induces G2/M arrest through modulation of p53/p21/CDC2/cyclin B1 pathways. ALS induced mitochondria-mediated apoptosis in MCF7 and MDA-MB-231 cells; ALS significantly decreased the expression of B-cell lymphoma 2 (Bcl-2), but increased the expression of B-cell lymphoma 2-associated X protein (Bax) and p53-upregulated modulator of apoptosis (PUMA), and increased the expression of cleaved caspases 3 and 9. ALS significantly increased the expression level of membrane-bound microtubule-associated protein 1 light chain 3 (LC3)-II and beclin 1 and induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase (MAPK) pathways in MCF7 and MDA-MB-231 cells as indicated by their altered phosphorylation, contributing to the pro-autophagic activities of ALS. Furthermore, treatment with wortmannin markedly downregulated ALS-induced p38 MAPK activation and LC3 conversion. In addition, knockdown of the p38 MAPK gene by ribonucleic acid interference upregulated Akt activation and resulted in LC3-II accumulation. These findings indicate that ALS promotes cellular

  3. Gadd45a and Gadd45b protect hematopoietic cells from UV-induced apoptosis via distinct signaling pathways, including p38 activation and JNK inhibition.

    PubMed

    Gupta, Mamta; Gupta, Shiv Kumar; Hoffman, Barbara; Liebermann, Dan A

    2006-06-30

    Gadd45a, Gadd45b, and Gadd45g (Gadd45/MyD118/CR6) are genes that are rapidly induced by genotoxic stress and have been implicated in genotoxic stress-induced responses, notably in apoptosis. Recently, using myeloid-enriched bone marrow (BM) cells obtained from wild-type (WT), Gadd45a-deficient, and Gadd45b-deficient mice, we have shown that in hematopoietic cells Gadd45a and Gadd45b play a survival function to protect hematopoietic cells from DNA-damaging agents, including ultra violet (UV)-induced apoptosis. The present study was undertaken to decipher the molecular paths that mediate the survival functions of Gadd45a and Gadd45b against genotoxic stress induced by UV radiation. It is shown that in hematopoietic cells exposed to UV radiation Gaddd45a and Gadd45b cooperate to promote cell survival via two distinct signaling pathways involving activation of the GADD45a-p38-NF-kappaB-mediated survival pathway and GADD45b-mediated inhibition of the stress response MKK4-JNK pathway.

  4. Endotoxin-induced skeletal muscle wasting is prevented by angiotensin-(1-7) through a p38 MAPK-dependent mechanism.

    PubMed

    Morales, María Gabriela; Olguín, Hugo; Di Capua, Gabriella; Brandan, Enrique; Simon, Felipe; Cabello-Verrugio, Claudio

    2015-09-01

    Skeletal muscle atrophy induced during sepsis syndrome produced by endotoxin in the form of LPS (lipopolysaccharide), is a pathological condition characterized by the loss of strength and muscle mass, an increase in MHC (myosin heavy chain) degradation, and an increase in the expression of atrogin-1 and MuRF-1 (muscle-specific RING-finger protein 1), two ubiquitin E3 ligases belonging to the ubiquitin-proteasome system. Ang-(1-7) [Angiotensin-(1-7)], through its Mas receptor, has beneficial effects in skeletal muscle. We evaluated in vivo the role of Ang-(1-7) and Mas receptor on the muscle wasting induced by LPS injection into C57BL/10J mice. In vitro studies were performed in murine C2C12 myotubes and isolated myofibres from EDL (extensor digitorum longus) muscle. In addition, the participation of p38 MAPK (mitogen-activated protein kinase) in the Ang-(1-7) effect on the LPS-induced muscle atrophy was evaluated. Our results show that Ang-(1-7) prevents the decrease in the diameter of myofibres and myotubes, the decrease in muscle strength, the diminution in MHC levels and the induction of atrogin-1 and MuRF-1 expression, all of which are induced by LPS. These effects were reversed by using A779, a Mas antagonist. Ang-(1-7) exerts these anti-atrophic effects at least in part by inhibiting the LPS-dependent activation of p38 MAPK both in vitro and in vivo. We have demonstrated for the first time that Ang-(1-7) counteracts the skeletal muscle atrophy induced by endotoxin through a mechanism dependent on the Mas receptor that involves a decrease in p38 MAPK phosphorylation. The present study indicates that Ang-(1-7) is a novel molecule with a potential therapeutic use to improve muscle wasting during endotoxin-induced sepsis syndrome.

  5. Protective effects of 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside in the MPTP-induced mouse model of Parkinson's disease: Involvement of reactive oxygen species-mediated JNK, P38 and mitochondrial pathways.

    PubMed

    He, Hong; Wang, Songhai; Tian, Jiyu; Chen, Lei; Zhang, Wei; Zhao, Junjie; Tang, Haifeng; Zhang, Xiaojun; Chen, Jianzong

    2015-11-15

    Parkinson's disease (PD) is characterized by the selective death of dopaminergic neurons in the substantia nigra pars compacta. Oxidative stress-induced neuron loss is thought to play a crucial role in the pathogenesis of PD. Previous work from our group suggests that 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG), an active component extracted from a traditional Chinese herb, Polygonum multiflorum thunb, can attenuate 1-methyl-4-phenyl pyridium-induced apoptosis in the neuronal cell line PC12, by inhibiting reactive oxygen species generation and modulating c-Jun N-terminal kinases (JNK) activation. Here, we investigated the protective effects of TSG against 1-methyl-4-phenyl-1,2,3,6-tetrahydropypridine (MPTP)-induced loss of tyrosine hydroxylase positive cells in mice and the underlying mechanisms. The results showed that MPTP-induced loss of tyrosine hydroxylase positive cells and reactive oxygen species generation were prevented by TSG in a dose-dependent manner. The reactive oxygen species scavenger N-acetylcysteine could also mitigate reactive oxygen species generation. Moreover, JNK and P38 were activated by MPTP, but extracellular signal-regulated protein kinases phosphorylation did not change after MPTP treatment. TSG at different doses blocked the activation of JNK and P38. The protective effect of TSG was also associated with downregulation of the bax/bcl-2 ratio, reversed the release of cytochrome c and smac, and inhibited the activation of caspase-3, -6, and -9 induced by MPTP. In conclusion, our studies demonstrated that the protective effects of TSG in the MPTP-induced mouse model of PD are involved, at least in part, in controlling reactive oxygen species-mediated JNK, P38, and mitochondrial pathways.

  6. C3 toxin activates the stress signaling pathways, JNK and p38, but antagonizes the activation of AP-1 in rat-1 cells.

    PubMed

    Beltman, J; Erickson, J R; Martin, G A; Lyons, J F; Cook, S J

    1999-02-05

    Lysophosphatidic acid (LPA) stimulates the c-Fos serum response element (SRE) by activating two distinct signal pathways regulated by the small GTPases, Ras and RhoA. Ras activates the ERK cascade leading to phosphorylation of the transcription factors Elk-1 and Sap1a at the Ets/TCF site. RhoA regulates an undefined pathway required for the activation of the SRF/CArG site. Here we have examined the role of the Ras and RhoA pathways in activation of the SRE and c-Fos expression in Rat-1 cells. Pertussis toxin and PD98059 strongly inhibited LPA-stimulated c-Fos expression and activation of a SRE:Luc reporter. C3 toxin completely inhibited RhoA function, partially inhibited SRE:Luc activity, but had no effect on LPA-stimulated c-Fos expression. Thus, in a physiological context the Ras-Raf-MEK-ERK pathway, but not RhoA, is required for LPA-stimulated c-Fos expression in Rat-1 cells. C3 toxin stimulated the stress-activated protein kinases JNK and p38 and potentiated c-Jun expression and phosphorylation; these properties were shared by another cellular stress agonist the protein kinase C inhibitor Ro-31-8220. However, C3 toxin alone or in combination with growth factors did not stimulate AP-1:Luc activity and actually antagonized the synergistic activation of AP-1:Luc observed in response to co-stimulation with growth factors and Ro-31-8220. These data indicate that C3 toxin is a cellular stress which antagonizes activation of AP-1 at a point downstream of stress-activated kinase activation or immediate-early gene induction.

  7. T-2 toxin is a cytochrome P450 1A1 inducer and leads to MAPK/p38- but not aryl hydrocarbon receptor-dependent interleukin-8 secretion in the human intestinal epithelial cell line Caco-2.

    PubMed

    Kruber, Pierre; Trump, Saskia; Behrens, Johann; Lehmann, Irina

    2011-06-18

    T-2 toxin (T-2) is a secondary metabolite produced by various mould species of the genus Fusarium and a common contaminant detectable in staple foods of cereal origin. In the present study the impact of this mycotoxin on the inflammatory response of the intestinal epithelial cell line Caco-2 was examined by measuring interleukin (IL)-8 secretion. A T-2 concentration dependent IL-8 up-regulation was detected in IL-1β stimulated and unstimulated Caco-2 cells. To elucidate the possible underlying molecular mechanism of this conditional T-2-provoked IL-8 induction, a possible involvement of the aryl hydrocarbon receptor (AHR) and the mitogen-activated protein kinase (MAPK) pathway was investigated. Like benzo-[a]-pyrene (B[a]P), a well known AHR ligand, T-2 led to cytochrome P450 1A1 (CYP1A1) mRNA expression in Caco-2 cells, which could be inhibited by the AHR antagonist resveratrol. However, resveratrol did not influence T-2-dependent IL-8 induction. Since T-2 did not lead to AHR-translocation in stably GFP-AHR-transfected cells, an AHR dependency of T-2-triggered IL-8 induction could be excluded. But finally, up to a total inhibition of T-2-induced IL-8 was obtained using p38 inhibitors. Therefore, we conclude that p38 MAPK is responsible for mediating the inflammatory properties of the type A trichothecene T-2.

  8. Phenolics extracted from tartary (Fagopyrum tartaricum L. Gaerth) buckwheat bran exhibit antioxidant activity, and an antiproliferative effect on human breast cancer MDA-MB-231 cells through the p38/MAP kinase pathway.

    PubMed

    Li, Fuhua; Zhang, Xiaoli; Li, Yao; Lu, Keke; Yin, Ran; Ming, Jian

    2017-01-25

    Phenolics extracted from tartary buckwheat (Fagopyrum tartaricum L. Gaerth) bran were analyzed quantitatively and qualitatively. The bioactivity of the phenolic extracts was evaluated, such as the antioxidant activity, and the inhibition capacity on the growth of cancer cells. The molecular mechanism for the inhibitive effect on cancer cells was explored. Results indicated that tartary buckwheat bran phenolics mainly exist in a free form, and free phenolics were twice as abundant as bound phenolics. Free caffeic acid (119.75 μg per 100 mg DW) and bound rutin (51.66 μg per 100 mg DW) represented the main free and bound phenolic compounds, respectively. The free phenolic extract contributed to the major (>90%) antioxidant activities including the oxygen radical antioxidant capacity (ORAC) and cellular antioxidant activity (CAA). The free phenolic extract exhibited anticancer activity for human breast cancer MDA-MB-231 cells in a dose-dependent manner. This significant inhibition effect was achieved through the p38/MAP kinase pathway by inducing cell apoptosis (up-regulating p-p38 and p-ASK1 expressions and down-regulating TRAF2 and p-p53 expressions), and negatively regulating the progression of the cell cycle from the G1 to S phase (increased expression of p21 and suppressed expressions of PCNA, cyclin D1 and CDK4). All these results indicated that tartary buckwheat bran could be a rich resource of natural antioxidants and inhibitors for the growth of MDA-MB-231 cells.

  9. Acquisition of contextual discrimination involves the appearance of a RAS-GRF1/p38 mitogen-activated protein (MAP) kinase-mediated signaling pathway that promotes long term potentiation (LTP).

    PubMed

    Jin, Shan-Xue; Arai, Junko; Tian, Xuejun; Kumar-Singh, Rajendra; Feig, Larry A

    2013-07-26

    RAS-GRF1 is a guanine nucleotide exchange factor with the ability to activate RAS and RAC GTPases in response to elevated calcium levels. We previously showed that beginning at 1 month of age, RAS-GRF1 mediates NMDA-type glutamate receptor (NMDAR)-induction of long term depression in the CA1 region of the hippocampus of mice. Here we show that beginning at 2 months of age, when mice first acquire the ability to discriminate between closely related contexts, RAS-GRF1 begins to contribute to the induction of long term potentiation (LTP) in the CA1 hippocampus by mediating the action of calcium-permeable, AMPA-type glutamate receptors (CP-AMPARs). Surprisingly, LTP induction by CP-AMPARs through RAS-GRF1 occurs via activation of p38 MAP kinase rather than ERK MAP kinase, which has more frequently been linked to LTP. Moreover, contextual discrimination is blocked by knockdown of Ras-Grf1 expression specifically in the CA1 hippocampus, infusion of a p38 MAP kinase inhibitor into the CA1 hippocampus, or the injection of an inhibitor of CP-AMPARs. These findings implicate the CA1 hippocampus in the developmentally dependent capacity to distinguish closely related contexts through the appearance of a novel LTP-supporting signaling pathway.

  10. Tetramethylpyrazine Suppresses Transient Oxygen-Glucose Deprivation-Induced Connexin32 Expression and Cell Apoptosis via the ERK1/2 and p38 MAPK Pathway in Cultured Hippocampal Neurons

    PubMed Central

    Cai, Lin; Ran, Maorong; Zhang, Yulan; Gong, Huaqu; Dai, Xuemei; Wu, Wei; Dong, Hailong

    2014-01-01

    Tetramethylpyrazine (TMP) has been widely used in China as a drug for the treatment of various diseases. Recent studies have suggested that TMP has a protective effect on ischemic neuronal damage. However, the exact mechanism is still unclear. This study aims to investigate the mechanism of TMP mediated ischemic hippocampal neurons injury induced by oxygen-glucose deprivation (OGD). The effect of TMP on hippocampal neurons viability was detected by MTT assay, LDH release assay and apoptosis rate was measured by flow cytometry. TMP significantly suppressed neuron apoptosis in a concentration-dependent manner. TMP could significantly reduce the elevated levels of connexin32 (Cx32) induced by OGD. Knockdown of Cx32 by siRNA attenuated OGD injury. Moreover, our study showed that viability was increased in siRNA-Cx32-treated-neurons, and neuron apoptosis was suppressed by activating Bcl-2 expression and inhibiting Bax expression. Over expression of Cx32 could decrease neurons viability and increase LDH release. Furthermore, OGD increased phosphorylation of ERK1/2 and p38, whose inhibitors relieved the neuron injury and Cx32 up-regulation. Taken together, TMP can reverse the OGD-induced Cx32 expression and cell apoptosis via the ERK1/2 and p38 MAPK pathways. PMID:25237906

  11. Atorvastatin promotes human monocyte differentiation toward alternative M2 macrophages through p38 mitogen-activated protein kinase-dependent peroxisome proliferator-activated receptor γ activation.

    PubMed

    Zhang, Ou; Zhang, Jinying

    2015-05-01

    M1 and M2 macrophages are detectable in human atherosclerotic lesions, and M2 macrophages are present at locations distant from the lipid core in more stable zones of the plaque and appear to exert anti-inflammatory properties on M1 macrophages. Peroxisome proliferator-activated receptor (PPAR) γ promotes the differentiation of monocytes into anti-inflammatory M2 macrophages. Although both statins and PPARγ ligands have been reported to protect against the progression of atherosclerosis, no data are currently available regarding the implication of statins in the alternative differentiation of human monocytes. In the present study, we hypothesized that atorvastatin may exert novel effects to prime human monocytes toward an anti-inflammatory alternative M2 phenotype. To this aim, we first found that abundant M2 markers were expressed in human circulating monocytes after atorvastatin treatment. Moreover, atorvastatin was able to induce PPARγ expression and activation in human monocytes in vivo and in vitro, resulting in priming primary human monocytes differentiation into M2 macrophages with a more pronounced paracrine anti-inflammatory activity in M1 macrophages. Additional data with molecular approaches revealed that p38 mitogen-activated protein kinase (MAPK) but not extracellular signal-regulated kinase (ERK) 1/2 activation was involved in atorvastatin-mediated PPARγ activation and enhanced alternative M2 macrophage phenotype. Collectively, our data demonstrated that atorvastatin promotes human monocyte differentiation toward alternative M2 macrophages via p38 MAPK-dependent PPARγ activation.

  12. Effect of TRPV4-p38 MAPK Pathway on Neuropathic Pain in Rats with Chronic Compression of the Dorsal Root Ganglion

    PubMed Central

    Qu, Yu-Juan; Zhang, Xiao; Fan, Zhen-Zhen; Huai, Juan; Teng, Yong-Bo; Zhang, Yang; Yue, Shou-Wei

    2016-01-01

    The aim of this study was to investigate the relationships among TRPV4, p38, and neuropathic pain in a rat model of chronic compression of the dorsal root ganglion. Mechanical allodynia appeared after CCD surgery, enhanced via the intrathecal injection of 4α-phorbol 12,13-didecanoate (4α-PDD, an agonist of TRPV4) and anisomycin (an agonist of p38), but was suppressed by Ruthenium Red (RR, an inhibitor of TRPV4) and SB203580 (an inhibitor of p38). The protein expressions of p38 and P-p38 were upregulated by 4α-PDD and anisomycin injection but reduced by RR and SB203580. Moreover, TRPV4 was upregulated by 4α-PDD and SB203580 and downregulated by RR and anisomycin. In DRG tissues, the numbers of TRPV4- or p38-positive small neurons were significantly changed in CCD rats, increased by the agonists, and decreased by the inhibitors. The amplitudes of ectopic discharges were increased by 4α-PDD and anisomycin but decreased by RR and SB203580. Collectively, these results support the link between TRPV4 and p38 and their intermediary role for neuropathic pain in rats with chronic compression of the dorsal root ganglion. PMID:27366753

  13. Effect of TRPV4-p38 MAPK Pathway on Neuropathic Pain in Rats with Chronic Compression of the Dorsal Root Ganglion.

    PubMed

    Qu, Yu-Juan; Zhang, Xiao; Fan, Zhen-Zhen; Huai, Juan; Teng, Yong-Bo; Zhang, Yang; Yue, Shou-Wei

    2016-01-01

    The aim of this study was to investigate the relationships among TRPV4, p38, and neuropathic pain in a rat model of chronic compression of the dorsal root ganglion. Mechanical allodynia appeared after CCD surgery, enhanced via the intrathecal injection of 4α-phorbol 12,13-didecanoate (4α-PDD, an agonist of TRPV4) and anisomycin (an agonist of p38), but was suppressed by Ruthenium Red (RR, an inhibitor of TRPV4) and SB203580 (an inhibitor of p38). The protein expressions of p38 and P-p38 were upregulated by 4α-PDD and anisomycin injection but reduced by RR and SB203580. Moreover, TRPV4 was upregulated by 4α-PDD and SB203580 and downregulated by RR and anisomycin. In DRG tissues, the numbers of TRPV4- or p38-positive small neurons were significantly changed in CCD rats, increased by the agonists, and decreased by the inhibitors. The amplitudes of ectopic discharges were increased by 4α-PDD and anisomycin but decreased by RR and SB203580. Collectively, these results support the link between TRPV4 and p38 and their intermediary role for neuropathic pain in rats with chronic compression of the dorsal root ganglion.

  14. Inhibition of cathepsin S confers sensitivity to methyl protodioscin in oral cancer cells via activation of p38 MAPK/JNK signaling pathways

    PubMed Central

    Hsieh, Ming-Ju; Lin, Chiao-Wen; Chen, Mu-Kuan; Chien, Su-Yu; Lo, Yu-Sheng; Chuang, Yi-Ching; Hsi, Yi-Ting; Lin, Chia-Chieh; Chen, Jui-Chieh; Yang, Shun-Fa

    2017-01-01

    Oral cancer is one of the most common cancers in the world. Approximately 90% of oral cancers are subtyped to oral squamous cell carcinoma (OSCC). Despite advances in diagnostic techniques and improvement in treatment modalities, the prognosis remains poor. Therefore, an effective chemotherapy mechanism that enhances tumor sensitivity to chemotherapeutics is urgently needed. Methyl protodioscin (MP) is a furostanol bisglycoside with a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. The aim of the present study was to determine the antitumor activity of MP on OSCC and its underlying mechanisms. Our results show that treatment of OSCC cells with MP potently inhibited cell viability. Moreover, MP leading to cell cycle arrest at G2/M phase, which subsequently activates caspase-3, -8, -9 and PARP to induce cell apoptosis. Meanwhile, we also demonstrate that MP induces a robust autophagy in OSCC cells. The results indicate cathepsin S (CTSS) is involved in MP-induced apoptosis and autophagy by modulation of p38 MAPK and JNK1/2 pathways. These findings may provide rationale to combine MP with CTSS blockade for the effective treatment of OSCC. PMID:28327651

  15. Vanillin Protects Dopaminergic Neurons against Inflammation-Mediated Cell Death by Inhibiting ERK1/2, P38 and the NF-κB Signaling Pathway.

    PubMed

    Yan, Xuan; Liu, Dian-Feng; Zhang, Xiang-Yang; Liu, Dong; Xu, Shi-Yao; Chen, Guang-Xin; Huang, Bing-Xu; Ren, Wen-Zhi; Wang, Wei; Fu, Shou-Peng; Liu, Ju-Xiong

    2017-02-12

    Neuroinflammation plays a very important role in the pathogenesis of Parkinson's disease (PD). After activation, microglia produce pro-inflammatory mediators that damage surrounding neurons. Consequently, the inhibition of microglial activation might represent a new therapeutic approach of PD. Vanillin has been shown to protect dopaminergic neurons, but the mechanism is still unclear. Herein, we further study the underlying mechanisms in lipopolysaccharide (LPS)-induced PD models. In vivo, we firstly established rat models of PD by unilateral injection of LPS into substantia nigra (SN), and then examined the role of vanillin in motor dysfunction, microglial activation and degeneration of dopaminergic neurons. In vitro, murine microglial BV-2 cells were treated with vanillin prior to the incubation of LPS, and then the inflammatory responses and the related signaling pathways were analyzed. The in vivo results showed that vanillin markedly improved the motor dysfunction, suppressed degeneration of dopaminergic neurons and inhibited microglial over-activation induced by LPS intranigral injection. The in vitro studies demonstrated that vanillin reduces LPS-induced expression of inducible nitric oxide (iNOS), cyclooxygenase-2 (COX-2), IL-1β, and IL-6 through regulating ERK1/2, p38 and NF-κB signaling. Collectively, these data indicated that vanillin has a role in protecting dopaminergic neurons via inhibiting inflammatory activation.

  16. Vanillin Protects Dopaminergic Neurons against Inflammation-Mediated Cell Death by Inhibiting ERK1/2, P38 and the NF-κB Signaling Pathway

    PubMed Central

    Yan, Xuan; Liu, Dian-Feng; Zhang, Xiang-Yang; Liu, Dong; Xu, Shi-Yao; Chen, Guang-Xin; Huang, Bing-Xu; Ren, Wen-Zhi; Wang, Wei; Fu, Shou-Peng; Liu, Ju-Xiong

    2017-01-01

    Neuroinflammation plays a very important role in the pathogenesis of Parkinson’s disease (PD). After activation, microglia produce pro-inflammatory mediators that damage surrounding neurons. Consequently, the inhibition of microglial activation might represent a new therapeutic approach of PD. Vanillin has been shown to protect dopaminergic neurons, but the mechanism is still unclear. Herein, we further study the underlying mechanisms in lipopolysaccharide (LPS)-induced PD models. In vivo, we firstly established rat models of PD by unilateral injection of LPS into substantia nigra (SN), and then examined the role of vanillin in motor dysfunction, microglial activation and degeneration of dopaminergic neurons. In vitro, murine microglial BV-2 cells were treated with vanillin prior to the incubation of LPS, and then the inflammatory responses and the related signaling pathways were analyzed. The in vivo results showed that vanillin markedly improved the motor dysfunction, suppressed degeneration of dopaminergic neurons and inhibited microglial over-activation induced by LPS intranigral injection. The in vitro studies demonstrated that vanillin reduces LPS-induced expression of inducible nitric oxide (iNOS), cyclooxygenase-2 (COX-2), IL-1β, and IL-6 through regulating ERK1/2, p38 and NF-κB signaling. Collectively, these data indicated that vanillin has a role in protecting dopaminergic neurons via inhibiting inflammatory activation. PMID:28208679

  17. P38-associated pathway involvement in apoptosis induced by photodynamic therapy with Lonicera japonica in human lung squamous carcinoma CH27 cells.

    PubMed

    Leung, Henry W-C; Hour, M-J; Chang, W-T; Wu, Y-C; Lai, M-Y; Wang, M-Y; Lee, H-Z

    2008-11-01

    Photodynamic therapy (PDT) is an effective therapy for local malignant tumors. Lonicera japonica was found to have the anti-tumor effect. The aim of this study is to explore the mechanisms of apoptosis induced by PDT in lung CH27 carcinoma cells with alcohol extract from Lonicera japonica as photosensitizer. Our study indicated that Lonicera japonica extracts exhibited significant photocytotoxicity in CH27 cells at a concentration range of 50-150 microg/ml, with 0.4-1.2J/cm2 light dose. PDT with Lonicera japonica extracts-induced cell death is a typical apoptosis that was accompanied by DNA condensation, externalization of phosphatidylserine and formation of apoptotic bodies. PDT with Lonicera japonica extracts was shown to be caspase-3-independent apoptosis via activation of AIF in this study. P38-associated pathway may be involved in apoptosis induced by PDT with Lonicera japonica extracts in CH27 cells. We also have demonstrated that PDT with Lonicera japonica extracts-induced CH27 cells apoptosis was probably related to its ability to change the protein expression and distribution of heat shock protein 27.

  18. Isoorientin induces apoptosis and autophagy simultaneously by reactive oxygen species (ROS)-related p53, PI3K/Akt, JNK, and p38 signaling pathways in HepG2 cancer cells.

    PubMed

    Yuan, Li; Wei, Shuping; Wang, Jing; Liu, Xuebo

    2014-06-11

    Cell death is closely related to autophagy under some circumstances; however, the effect of isoorientin (ISO) on autophagy and the interplay between apoptosis and autophagy in human hepatoblastoma cancer (HepG2) cells remains poorly understood. The present study showed that ISO induced autophagy, which was correlated with the formation of autophagic vacuoles and the overexpression of Beclin-1 and LC3-II. The autophagy inhibitor 3-methyladenine (3-MA) markedly inhibited apoptosis, and the apoptosis inhibitor ZVAD-fmk also decreased ISO-induced autophagy. In addition, the PI3K/Akt inhibitor LY294002 enhanced Beclin-1, LC3-II, and poly(ADP-ribose) polymerase (PARP) cleavage levels. Also, the reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine (NAC), the JNK inhibitor SP600125, and the p38 inhibitor SB203580 efficiently downregulated the levels of these proteins. Moreover, the p53 inhibitor pifithrin-α and the nuclear factor (NF)-κB inhibitor pyrrolidinedithiocarbamic acid (PDTC) clearly suppressed Beclin-1 and LC3-II and increased cytochrome c release, caspase-3 activation, and PARP cleavage. These results demonstrated for the first time that ISO simultaneously induced apoptosis and autophagy by ROS-related p53, PI3K/Akt, JNK, and p38 signaling pathways. Furthermore, ISO-induced apoptosis by activating the Fas receptor-mediated apoptotic pathway and suppressing the p53 and PI3K/Akt-dependent NF-κB signaling pathway, with the subsequent increase in the release of cytochrome c, caspase-3 activation, and PARP cleavage.

  19. TGFβ can stimulate the p(38)/β-catenin/PPARγ signaling pathway to promote the EMT, invasion and migration of non-small cell lung cancer (H460 cells).

    PubMed

    Lin, Li-Chiung; Hsu, Shih-Lan; Wu, Chieh-Liang; Hsueh, Chi-Mei

    2014-12-01

    Signaling pathway(s) responsible for transforming growth factor β (TGFβ)-induced epithelial mesenchymal transition (EMT), invasion and migration of H460 cells (non-small cell lung cancer/NSCLC) was identified in the study. The results showed that TGFβ-induced p(38)/β-catenin/PPARγ signaling pathway played a critical role in the promotion of EMT, invasion and migration of H460 cells. All these pathological outcomes attributed to PPARγ-increased expression of p-EGFR, p-c-MET and Vimentin and the decrease of E-cadherin. Transforming growth factor β and p(38)-induced β-catenin not only stimulated the expression of PPARγ but also physically interacted with it. Blocking the ligand binding domain of PPARγ (with GW9662) could significantly interfere the binding between PPARγ and β-catenin, and interrupt the nuclear infiltration of both factors. These findings suggested that β-catenin was an upstream regulator and a ligand of PPARγ, and the binding between these two molecules was critical for their nuclear infiltration. Transforming growth factor β-induced tumor invasion and migration was also seen in U373 cells (brain glioma, with high inducible PPARγ) in a PPARγ-dependent manner, but not in CH27 cells (squamous NSCLC, with low PPARγ). PPARγ shRNA, GW9662, JW67 and 2,4-diaminoquinazoline were all revealed to have important values in the control of the intrinsic and TGFβ-induced EMT, tumor invasion and migration of H460 cells. The results further suggested that PPARγ and β-catenin may be the potential markers for the early diagnosis and/or treatment of metastatic tumors.

  20. Activation of p38-MAPK by CXCL4/CXCR3 axis contributes to p53-dependent intestinal apoptosis initiated by 5-fluorouracil.

    PubMed

    Gao, Jing; Gao, Jin; Qian, Lan; Wang, Xia; Wu, Mingyuan; Zhang, Yang; Ye, Hao; Zhu, Shunying; Yu, Yan; Han, Wei

    2014-08-01

    Chemotherapy-induced mucositis (CIM) is a major does limiting side-effect of chemoagents such as 5-fluorouracil (5-FU). Molecules involved in this disease process are still not fully understood. We proposed that the homeostatically regulated genes during CIM may participate in the disease. A cluster of such genes were previously identified by expression gene-array from the mouse jejunum in 5-FU-induced mucositis model. Here, we report that CXCL4 is such a homeostatically regulated gene and serves as a new target for the antibody treatment of CIM. CXCL4 and its receptor CXCR3 were confirmed at both the gene and protein levels to be homeostatically regulated during 5-FU-induced mucositis. Using of CXCL4 neutralizing monoclonal antibody (CXCL4mab) decreased the incidence, severity, and duration of the chemotherapy-induced diarrhea, the major symptom of CIM, in a 5-FU mouse CIM model. Mechanistically, CXCL4mab reduced the apoptosis of the crypt epithelia by suppression of the 5-FU-induced expression of p53 and Bax through its receptor CXCR3. The downstream signaling pathway of CXCL4 in activation of the epithelial apoptosis was identified in an intestinal epithelial cell line (IEC-6). CXCL4 activated the phosphorylation of p38 MAPK, which mediated the stimulated expression of p53 and Bax, and resulted in the ultimate activation of Caspase-8, -9, and -3. Taken together, activation of CXCL4 expression by 5-FU in mice participates in 5-FU-induced intestinal mucositis through upregulation of p53 via activation of p38-MAPK, and CXCL4mab is potentially beneficial in preventing CIM in the intestinal tract.

  1. c-Ski inhibits the proliferation of vascular smooth muscle cells via suppressing Smad3 signaling but stimulating p38 pathway.

    PubMed

    Li, Jun; Li, Ping; Zhang, Yan; Li, Gong-Bo; Zhou, Yuan-Guo; Yang, Kang; Dai, Shuang-Shuang

    2013-01-01

    Proliferation of vascular smooth muscle cells (VSMCs) plays key roles in the progression of intimal hyperplasia, but the molecular mechanisms that trigger VSMC proliferation after vascular injury remain unclear. c-Ski, a co-repressor of transforming growth factor β (TGF-β)/Smad signaling, was detected to express in VSMC of rat artery. During the course of arterial VSMC proliferation induced by balloon injury in rat, the endogenous protein expressions of c-Ski decreased markedly in a time-dependent manner. In vivo c-Ski gene delivery was found to significantly suppress balloon injury-induced VSMC proliferation and neointima formation. Further investigation in A10 rat aortic smooth muscle cells demonstrated that overexpression of c-Ski gene inhibited TGF-β1 (1 ng/ml)-induced A10 cell proliferation while knockdown of c-Ski by RNAi enhanced the stimulatory effect of TGF-β1 on A10 cell growth. Western blot for signaling detection showed that suppression of Smad3 phosphorylation while stimulating p38 signaling associated with upregulation of cyclin-dependent kinase inhibitors p21 and p27 was responsible for the inhibitory effect of c-Ski on TGF-β1-induced VSMC proliferation. These data suggest that the decrease of endogenous c-Ski expression is implicated in the progression of VSMC proliferation after arterial injury and c-Ski administration represents a promising role for treating intimal hyperplasia via inhibiting the proliferation of VSMC.

  2. Extract of Polygala tenuifolia Alleviates Stress-Exacerbated Atopy-Like Skin Dermatitis through the Modulation of Protein Kinase A and p38 Mitogen-Activated Protein Kinase Signaling Pathway

    PubMed Central

    Sur, Bongjun; Lee, Bombi; Yoon, Ye Seul; Lim, Pooreum; Hong, Riwon; Yeom, Mijung; Lee, Hyang Sook; Park, Hijoon; Shim, Insop; Lee, Hyejung; Jang, Young Pyo; Hahm, Dae-Hyun

    2017-01-01

    Atopic dermatitis (AD) and stress create a vicious cycle: stress exacerbates atopic symptoms, and atopic disease elicits stress and anxiety. Targeting multiple pathways including stress and allergic inflammation is, therefore, important for treating AD. In this study, we investigated the remedial value of Polygala tenuifolia Willd. (PTW) for treating immobilization (IMO) stress-exacerbated atopy-like skin dermatitis and its underlying mechanism. Trimellitic anhydride (TMA) was applied to dorsal skin for sensitization and subsequently both ears for eliciting T-cell-dependent contact hypersensitivity in mice, which underwent 2 h-IMO stress and PTW administration for the latter 6 and 9 days in the ear exposure period of TMA, respectively. To elicit in vitro degranulation of human mast cell line-1 (HMC-1), 10 µM substance P (SP) and 200 nM corticotrophin-releasing factor (CRF) were sequentially added with 48 h-interval. PTW extract (500 µg/mL) was added 30 min before CRF treatment. IMO stress exacerbated TMA-induced scratching behavior by 252%, and increased their blood corticosterone levels by two-fold. Treatment with 250 mg/kg PTW significantly restored IMO stress-exacerbated scratching behavior and other indicators such as skin inflammation and water content, lymph node weights, and serum histamine and immunoglobulin E (lgE) levels. Furthermore, it also reversed TMA-stimulated expression of tumor necrosis factor (TNF)-α and interleukin (IL)-4 mRNAs in ear tissues. PTW significantly inhibited SP/CRF-stimulated degranulation of HMC-1 cells, subsequent tryptase secretion, and protein kinase A (PKA) activity. PTW also selectively inhibited p38 mitogen-activated protein kinase (MAPK) phosphorylation in SP/CRF-treated HMC-1 cells. PTW significantly inhibited HMC-1 cell degranulation and alleviated IMO stress-exacerbated atopic dermatitis symptoms by modulating the PKA/p38 MAPK signaling pathway. PMID:28106783

  3. Nephroprotective Effects of N-Acetylcysteine Amide against Contrast-Induced Nephropathy through Upregulating Thioredoxin-1, Inhibiting ASK1/p38MAPK Pathway, and Suppressing Oxidative Stress and Apoptosis in Rats

    PubMed Central

    Duan, Yiru; Zheng, Junli; Wang, Yiquan; Wang, Guohua; Norgren, Svante; Hei, Tom K.

    2016-01-01

    Contrast-induced nephropathy (CIN) is a leading cause of hospital-acquired acute kidney injury (AKI) due to apoptosis induced in renal tubular cells. Our previous study demonstrated the novel N-acetylcysteine amide (NACA); the amide form of N-acetyl cysteine (NAC) prevented renal tubular cells from contrast-induced apoptosis through inhibiting p38 MAPK pathway in vitro. In the present study, we aimed to compare the efficacies of NACA and NAC in preventing CIN in a well-established rat model and investigate whether thioredoxin-1 (Trx1) and apoptosis signal-regulating kinase 1 (ASK1) act as the potential activator for p38 MAPK. NACA significantly attenuated elevations of serum creatinine, blood urea nitrogen, and biomarkers of AKI. At equimolar concentration, NACA was more effective than NAC in reducing histological changes of renal tubular injuries. NACA attenuated activation of p38 MAPK signal, reduced oxidative stress, and diminished apoptosis. Furthermore, we demonstrated that contrast exposure resulted in Trx1 downregulation and increased ASK1/p38 MAPK phosphorylation, which could be reversed by NACA and NAC. To our knowledge, this is the first report that Trx1 and ASK1 are involved in CIN. Our study highlights a renal protective role of NACA against CIN through modulating Trx1 and ASK1/p38 MAPK pathway to result in the inhibition of apoptosis among renal cells. PMID:28105252

  4. Cranberry extract standardized for proanthocyanidins promotes the immune response of Caenorhabditis elegans to Vibrio cholerae through the p38 MAPK pathway and HSF-1.

    PubMed

    Dinh, Jessica; Angeloni, Joseph T; Pederson, Daniel B; Wang, Xiaoxia; Cao, Min; Dong, Yuqing

    2014-01-01

    Botanicals are rich in bioactive compounds, and some offer numerous beneficial effects to animal and human health when consumed. It is well known that phytochemicals in cranberries have anti-oxidative and antimicrobial activities. Recently, an increasing body of evidence has demonstrated that cranberry phytochemicals may have potential benefits that promote healthy aging. Here, we use Caenorhabditis elegans as a model to show that water-soluble cranberry extract standardized to 4.0% proanthocyanidins (WCESP), a major component of cranberries, can enhance host innate immunity to resist against Vibrio cholerae (V. cholerae; wild type C6706 (O1 El Tor biotype)) infection. Supplementation of WCESP did not significantly alter the intestinal colonization of V. cholerae, but upregulated the expression of C. elegans innate immune genes, such as clec-46, clec-71, fmo-2, pqn-5 and C23G10.1. Additionally, WCESP treatment did not affect the growth of V. cholerae and expression of the major bacterial virulence genes, and only slightly reduced bacterial colonization within C. elegans intestine. These findings indicate that the major components of WCESP, including proanthocyanidins (PACs), may play an important role in enhancing the host innate immunity. Moreover, we engaged C. elegans mutants and identified that the p38 MAPK signaling, insulin/IGF-1 signaling (IIS), and HSF-1 play pivotal roles in the WCESP-mediated host immune response. Considering the level of conservation between the innate immune pathways of C. elegans and humans, the results of this study suggest that WCESP may also play an immunity-promoting role in higher order organisms.

  5. Remodeling of the Fission Yeast Cdc42 Cell-Polarity Module via the Sty1 p38 Stress-Activated Protein Kinase Pathway.

    PubMed

    Mutavchiev, Delyan R; Leda, Marcin; Sawin, Kenneth E

    2016-11-07

    The Rho family GTPase Cdc42 is a key regulator of eukaryotic cellular organization and cell polarity [1]. In the fission yeast Schizosaccharomyces pombe, active Cdc42 and associated effectors and regulators (the "Cdc42 polarity module") coordinate polarized growth at cell tips by controlling the actin cytoskeleton and exocytosis [2-4]. Localization of the Cdc42 polarity module to cell tips is thus critical for its function. Here we show that the fission yeast stress-activated protein kinase Sty1, a homolog of mammalian p38 MAP kinase, regulates localization of the Cdc42 polarity module. In wild-type cells, treatment with latrunculin A, a drug that leads to actin depolymerization, induces dispersal of the Cdc42 module from cell tips and cessation of polarized growth [5, 6]. We show that latrunculin A treatment also activates the Sty1 MAP kinase pathway and, strikingly, we find that loss of Sty1 MAP kinase signaling prevents latrunculin A-induced dispersal of the Cdc42 module, allowing polarized growth even in complete absence of the actin cytoskeleton. Regulation of the Cdc42 module by Sty1 is independent of Sty1's role in stress-induced gene expression. We also describe a system for activation of Sty1 kinase "on demand" in the absence of any external stress, and use this to show that Sty1 activation alone is sufficient to disperse the Cdc42 module from cell tips in otherwise unperturbed cells. During nitrogen-starvation-induced quiescence, inhibition of Sty1 converts non-growing, depolarized cells into growing, polarized cells. Our results place MAP kinase Sty1 as an important physiological regulator of the Cdc42 polarity module.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-10-01

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

  8. Oscillation of p38 activity controls efficient pro-inflammatory gene expression

    PubMed Central

    Tomida, Taichiro; Takekawa, Mutsuhiro; Saito, Haruo

    2015-01-01

    The p38 MAP kinase signalling pathway controls inflammatory responses and is an important target of anti-inflammatory drugs. Although pro-inflammatory cytokines such as interleukin-1β (IL-1β) appear to induce only transient activation of p38 (over ∼60 min), longer cytokine exposure is necessary to induce p38-dependent effector genes. Here we study the dynamics of p38 activation in individual cells using a Förster resonance energy transfer (FRET)-based p38 activity reporter. We find that, after an initial burst of activity, p38 MAPK activity subsequently oscillates for more than 8 h under continuous IL-1β stimulation. However, as this oscillation is asynchronous, the measured p38 activity population average is only slightly higher than basal level. Mathematical modelling, which we have experimentally verified, indicates that the asynchronous oscillation of p38 is generated through a negative feedback loop involving the dual-specificity phosphatase MKP-1/DUSP1. We find that the oscillatory p38 activity is necessary for efficient expression of pro-inflammatory genes such as IL-6, IL-8 and COX-2. PMID:26399197

  9. Pathogenic Vibrio harveyi, in contrast to non-pathogenic strains, intervenes with the p38 MAPK pathway to avoid an abalone haemocyte immune response.

    PubMed

    Travers, Marie-Agnès; Le Bouffant, Ronan; Friedman, Carolyn S; Buzin, Florence; Cougard, Bertrand; Huchette, Sylvain; Koken, Marcel; Paillard, Christine

    2009-01-01

    Vibrio harveyi is a marine bacterial pathogen responsible for episodic abalone epidemics associated with massive mortalities in France, Japan, and Australia. The aim of this study was the understanding of a possible role of the p38 MAPK in abalone haemocyte responses towards this bacterium. First, the pathogenicity of different V. harveyi strains was compared in both immersion and injection trials, and clear differences were detected. The three strains, ORM4, 04/092, and 05/053, all isolated from moribund abalone, induced up to 80% mortalities in immersion or injection challenges (LD(50) (ORM4) = 2.5 x 10(2) CFU animal(-1)). The two strains, LMG 4044T and LMG 7890 were non-pathogenic towards abalone in immersion trials, and needed very high numbers for killing by intramuscular injections (LD(50) = 8.9 x 10(4) and 1.6 x 10(5) CFU animal(-1), respectively). To start unraveling the mechanism explaining these differences, the p38-MAPK, a keyplayer in antimicrobial immune response, was studied. The non-pathogenic strain, LMG 7890 can be eliminated by abalone haemocytes and induces haemocyte phagocytosis and high ROS production. With different concentrations of a p38-specific inhibitor, SB203580, p38 implication was shown. This inhibitor reduced phagocytosis and ROS induction leading to LMG 7890 proliferation. In the case of the pathogenic ORM4 which can not be eliminated by abalone haemocytes, no phagocytosis and ROS production was induced, and a retarded p38 activation was observed. Taken together, our results suggest that p38 MAPK modulation may be one of the ways of virulent V. harveyi to attack its host and escape abalone immune response.

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

    PubMed Central

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

    2016-01-01

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

  11. Additive effect of heat on the UVB-induced tyrosinase activation and melanogenesis via ERK/p38/MITF pathway in human epidermal melanocytes.

    PubMed

    Gu, Wei-Jie; Ma, Hui-Jun; Zhao, Guang; Yuan, Xiao-Ying; Zhang, Ping; Liu, Wen; Ma, Li-Juan; Lei, Xiao-Bing

    2014-08-01

    Heat is known as an environmental factor that causes significant skin pigmentation, but its effects on melanogenesis have been poorly studied. It has been shown that mitogen-activated protein kinase (MAPK) is involved in ultraviolet B (UVB) and stress-induced melanogenesis in melanocytes. In this study, we investigated the effects of heat and UVB, on melanocyte melanogenesis, differentiation, and MAPK phosphorylation. The results showed that heat (1 h at 40 °C for 5 days) increased cell dendrites, enlarged cell bodies, and induced extracellular signal-regulated kinases (ERK)/p38/MITF activation but did not influence melanogenesis of human epidermal melanocytes from skin phototype III. UVB irradiation (20 mJ/cm(2) for 5 days) induced melanogenesis and c-jun N-terminal kinases (JNK)/p38/MITF/tyrosinase activation in melanocytes from skin phototype III. UVB combined with heat resulted in much more significant tyrosinase activation and melanogenesis as compared with UVB alone in melanocytes from skin phototype III. Furthermore, heat treatment and UVB irradiation induced JNK, ERK, and p38 activation but not melanogenic and morphological changes in melanocytes from skin phototype I. These findings suggested that heat promoted melanocyte differentiation, probably via heat-induced ERK/p38/MITF/activation. Furthermore, heat had an additive effect on the UVB-induced tyrosinase activation and melanogenesis. These results provide a new clue for dermatologists for the treatment of hypopigmented skin disease with heat combined with UVB irradiation.

  12. The Pore-Forming Toxin β hemolysin/cytolysin Triggers p38 MAPK-Dependent IL-10 Production in Macrophages and Inhibits Innate Immunity

    PubMed Central

    Bebien, Magali; Hensler, Mary E.; Davanture, Suzel; Hsu, Li-Chung; Karin, Michael; Park, Jin Mo; Alexopoulou, Lena; Liu, George Y.; Nizet, Victor; Lawrence, Toby

    2012-01-01

    Group B Streptococcus (GBS) is a leading cause of invasive bacterial infections in human newborns and immune-compromised adults. The pore-forming toxin (PFT) β hemolysin/cytolysin (βh/c) is a major virulence factor for GBS, which is generally attributed to its cytolytic functions. Here we show βh/c has immunomodulatory properties on macrophages at sub-lytic concentrations. βh/c-mediated activation of p38 MAPK drives expression of the anti-inflammatory and immunosuppressive cytokine IL-10, and inhibits both IL-12 and NOS2 expression in GBS-infected macrophages, which are critical factors in host defense. Isogenic mutant bacteria lacking βh/c fail to activate p38-mediated IL-10 production in macrophages and promote increased IL-12 and NOS2 expression. Furthermore, targeted deletion of p38 in macrophages increases resistance to invasive GBS infection in mice, associated with impaired IL-10 induction and increased IL-12 production in vivo. These data suggest p38 MAPK activation by βh/c contributes to evasion of host defense through induction of IL-10 expression and inhibition of macrophage activation, a new mechanism of action for a PFT and a novel anti-inflammatory role for p38 in the pathogenesis of invasive bacterial infection. Our studies suggest p38 MAPK may represent a new therapeutic target to blunt virulence and improve clinical outcome of invasive GBS infection. PMID:22829768

  13. TSG-6 secreted by mesenchymal stem cells suppresses immune reactions influenced by BMP-2 through p38 and MEK mitogen-activated protein kinase pathway.

    PubMed

    Um, Soyoun; Kim, Hui Young; Lee, Joo-Hee; Song, In-Seok; Seo, Byoung Moo

    2017-02-28

    Bone morphogenetic protein 2 (BMP-2) has a critical function in bone and cartilage development and in repairing damaged organs and tissue. However, clinical use of BMP-2 at doses of 0.5-1 mg/ml for orthopedics has been associated with severe postoperative swelling requiring emergency surgical intervention. We determined whether a high concentration of BMP-2 induces inflammatory responses in macrophages and the suppression of osteogenesis in hMSCs. We obtained human periodontal ligament stem cells and bone marrow stem cells from the maxilla, i.e., human mesenchymal stem cells (hMSCs), from the periodontal ligament of extracted third molar teeth and from the bone marrow of the maxilla, respectively. Osteogenic differentiation was measured by alkaline phosphatase activity and alizarin red S staining. Proteins were assessed by flow cytometry, enzyme-linked immunosorbent assay, Western blot and immunocytochemistry. Changes of gene expression were measured by reverse transcription plus the polymerase chain reaction (RT-PCR) and real-time PCR. A high BMP-2 concentration inhibited the early stages of osteogenesis in hMSCs. Co-culturing THP-1 cells (human monocytic cells) with hMSCs reduced the late stages of osteogenesis compared with those seen in hMSCs alone. In addition, high-dose BMP-2 induced the expression of inflammatory cytokines in THP-1 cells and the expression of the anti-inflammatory cytokine tumor-necrosis-factor-α-inducible gene 6 protein (TSG-6) in hMSCs. Consistent with the anti-inflammatory effects of hMSCs when co-cultured with THP-1 cells, interleukin-1β expression was downregulated by TSG-6 treatment of THP-1 cells. Our findings suggest that a high BMP-2 concentration triggers inflammation that causes inflammatory cytokine release from THP-1 cells, leading to the suppression of osteogenesis, whereas TSG-6 secreted by hMSCs suppresses inflammatory reactions through p38 and ERK in the mitogen-activated protein kinase pathway.

  14. Telmisartan, a possible PPAR-δ agonist, reduces TNF-α-stimulated VEGF-C production by inhibiting the p38MAPK/HSP27 pathway in human proximal renal tubular cells

    SciTech Connect

    Kimura, Hideki; Mikami, Daisuke; Kamiyama, Kazuko; Sugimoto, Hidehiro; Kasuno, Kenji; Takahashi, Naoki; Yoshida, Haruyoshi; Iwano, Masayuki

    2014-11-14

    Highlights: • TNF-α increased VEGF-C expression by enhancing phosphorylation of p38MAPK and HSP27. • Telmisartan decreased TNF-α-stimulated expression of VEGF-C. • Telmisartan suppressed TNF-α-induced phosphorylation of p38MAPK and HSP27. • Telmisartan activated endogenous PPAR-δ protein. • Telmisartan suppressed p38MAPK phosphorylation in a PPAR-δ-dependent manner. - Abstract: Vascular endothelial growth factor-C (VEGF-C) is a main inducer of inflammation-associated lymphangiogenesis in various inflammatory disorders including chronic progressive kidney diseases, for which angiotensin II receptor type 1 blockers (ARBs) are widely used as the main treatment. Although proximal renal tubular cells may affect the formation of lymphatic vessels in the interstitial area by producing VEGF-C, the molecular mechanisms of VEGF-C production and its manipulation by ARB have not yet been examined in human proximal renal tubular epithelial cells (HPTECs). In the present study, TNF-α dose-dependently induced the production of VEGF-C in HPTECs. The TNF-α-induced production of VEGF-C was mediated by the phosphorylation of p38MAPK and HSP27, but not by that of ERK or NFkB. Telmisartan, an ARB that can activate the peroxisome proliferator-activated receptor (PPAR), served as a PPAR-δ activator and reduced the TNF-α-stimulated production of VEGF-C. This reduction was partially attributed to a PPAR-δ-dependent decrease in p38MAPK phosphorylation. Our results indicate that TNF-α induced the production of VEGF-C in HPTECs by activating p38MAPK/HSP27, and this was partially inhibited by telmisartan in a PPAR-δ dependent manner. These results provide a novel insight into inflammation-associated lymphangiogenesis.

  15. HMGB1-TLR4 Axis Plays a Regulatory Role in the Pathogenesis of Mesial Temporal Lobe Epilepsy in Immature Rat Model and Children via the p38MAPK Signaling Pathway.

    PubMed

    Yang, Weihong; Li, Jing; Shang, Yun; Zhao, Li; Wang, Mingying; Shi, Jipeng; Li, Shujun

    2017-02-07

    The HMGB1-TLR4 axis is activated in adult mouse models of acute and chronic seizure. Nevertheless, whether HMGB1 was involved in the pathogenesis of mesial temporal lobe epilepsy (MTLE) remains unknown. In this study, we first measured the dynamic expression patterns of HMGB1 and TLR4 in the hippocampi of a rat model and in children with MTLE, as well as the levels of TNF-α and IL-1β. In addition, HMGB1 was added to mimic the process of inflammatory response in neurons. Neuronal somatic size and dendritic length were measured by immunohistochemistry and digital imaging. The results showed that the expression of HMGB1 and TLR4 as well as the levels of TNF-α and IL-1β were higher in the three stages of MTLE development in the rat model and in the children with MTLE. HMGB1 increased the levels of TNF-α and IL-1β, upregulated the protein level of p-p38MAPK and promoted the growth of cell somatic size and dendritic length in neurons. Pre-treatment with p38MAPK inhibitor SB203580 decreased the levels of TNF-α and IL-1β, while downregulation of TLR4 significantly reduced HMGB1-induced p38MAPK signaling pathway activation. These data demonstrated that the HMGB1-TLR4 axis may play an important role in the pathogenesis of MTLE via the p38MAPK signaling pathway.

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

    PubMed Central

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

    2016-01-01

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

  17. Dioscin alleviates BDL- and DMN-induced hepatic fibrosis via Sirt1/Nrf2-mediated inhibition of p38 MAPK pathway.

    PubMed

    Gu, Lina; Tao, Xufeng; Xu, Youwei; Han, Xu; Qi, Yan; Xu, Lina; Yin, Lianhong; Peng, Jinyong

    2016-02-01

    Oxidative stress is involved in hepatic stellate cells (HSCs) activation and extracellular matrix overproduction. We previously reported the promising effects of dioscin against CCl4-induced liver fibrosis, but its effects and mechanisms on BDL- and DMN-induced liver fibrosis remain unknown. The results in the present study indicated that dioscin significantly inhibited HSCs activation and attenuated hepatic fibrosis in rats. Furthermore, dioscin markedly up-regulated the levels of sirtuin 1 (Sirt1), HO-1, GST, GCLC and GCLM via increasing the nuclear translocation of nuclear erythroid factor 2-related factor 2 (Nrf2), which in turn inhibited mitogen-activated protein kinase 14 (p38 MAPK) phosphorylation and reduced the levels of COL1A1, COL3A1, α-SMA and fibronectin. These results were further validated by knockdown of Sirt1 and Nrf2 using siRNAs silencing, and abrogation of p38 MAPK using SB-203580 (a p38 MAPK inhibitor) in HSC-T6 and LX-2 cells. Collectively, our findings confirmed the potent effects of dioscin against liver fibrosis and also provided novel insights into the mechanisms of this compound as a candidate for the prevention of liver fibrosis in the future.

  18. Magnolol reduced TNF-α-induced vascular cell adhesion molecule-1 expression in endothelial cells via JNK/p38 and NF-κB signaling pathways.

    PubMed

    Liang, Chan-Jung; Lee, Chiang-Wen; Sung, Hsin-Ching; Chen, Yung-Hsiang; Wang, Shu-Huei; Wu, Pei-Jhen; Chiang, Yao-Chang; Tsai, Jaw-Shiun; Wu, Chau-Chung; Li, Chi-Yuan; Chen, Yuh-Lien

    2014-01-01

    Expression of cell adhesion molecules by the endothelium and the attachment of leukocytes to these cells play major roles in inflammation and cardiovascular disorders. Magnolol, a major active component of Magnolia officinalis, has antioxidative and anti-inflammatory properties. In the present study, the effects of magnolol on the expression of vascular cell adhesion molecule-1 (VCAM-1) in human aortic endothelial cells (HAECs) and the related mechanisms were investigated. TNF-α induced VCAM-1 protein expression and mRNA stability were significantly decreased in HAECs pre-treated with magnolol. Magnolol significantly reduced the phosphorylation of ERK, JNK, and p38 in TNF-α-treated HAECs. The decrease in VCAM-1 expression in response to TNF-α treatment was affected by JNK and p38 inhibitors, not by an ERK inhibitor. Magnolol also attenuates NF-κB activation and the translocation of HuR (an RNA binding protein) in TNF-α-stimulated HAECs. The VCAM-1 expression was weaker in the aortas of TNF-α-treated apo-E deficient mice with magnolol treatment. These data demonstrate that magnolol inhibits TNF-α-induced JNK/p38 phosphorylation, HuR translocation, NF-κB activation, and thereby suppresses VCAM-1 expression resulting in reduced leukocyte adhesion. Taken together, these results suggest that magnolol has an anti-inflammatory property and may play an important role in the prevention of atherosclerosis and inflammatory responses.

  19. Proinflammatory cytokines, IL-1β and TNF-α, induce expression of interleukin-34 mRNA via JNK- and p44/42 MAPK-NF-κB pathway but not p38 pathway in osteoblasts.

    PubMed

    Eda, Hiroyuki; Shimada, Hideaki; Beidler, David R; Monahan, Joseph B

    2011-11-01

    The aim of this study is to investigate the induction of interleukin-34 (IL-34) and macrophage colony-stimulating factor (M-CSF) mRNA by inflammatory cytokines and the involvement of mitogen-activated protein kinases (MAPKs) in this signaling pathway in human osteoblasts as both IL-34 and M-CSF bind to the same receptor c-FMS. Among four inflammatory cytokines [(IL-1β, IL-6, IL-17, and tumor necrosis factor-α (TNF-α)], IL-34 mRNA expression level was dramatically induced by IL-1β (17-fold) and TNF-α (74-fold). IL-1β and TNF-α activated the intracellular mitogen-activated protein kinases (MAPKs): p44/42 MAPK, p38, and c-Jun N-terminal kinase (JNK) as well as nuclear factor-κB (NF-κB) in osteoblasts. IL-1β- and TNF-α-mediated induction of IL-34 mRNA expression was decreased by JNK inhibitor. Interestingly, although treatment of MEK-1/2 inhibitor showed no reduction in the increase of IL-34 mRNA expression by cytokines, combination of MEK-1/2 inhibitor and JNK inhibitor significantly inhibited IL-1β- and TNF-α-mediated IL-34 mRNA expression level compared to those by each inhibitor alone. On the other hand, M-CSF mRNA expression level was significantly induced by both IL-1β and TNF-α by up to 7- and 11-fold, respectively. IL-1β- and TNF-α-mediated induction of M-CSF mRNA was not affected by p38, JNK, and MEK-1/2 inhibitors. However, NF-κB inhibitor completely inhibited the elevation of M-CSF mRNA expression by these cytokines. These results showed that proinflammatory cytokines, IL-1β and TNF-α, induced the expression of IL-34 mRNA via JNK and p44/42 MAPK but not p38 in human osteoblasts while p38, JNK, and p44/42 MAPK were not involved in the induction of M-CSF mRNA expression by these cytokines.

  20. p38 mitogen-activated protein kinase activation by ultraviolet A radiation in human dermal fibroblasts.

    PubMed

    Le Panse, Rozen; Dubertret, Louis; Coulomb, Bernard

    2003-08-01

    UVA radiation penetrates deeply into the skin reaching both the epidermis and the dermis. We thus investigated the effects of naturally occurring doses of UVA radiation on mitogen-activated protein kinase (MAPK) activities in human dermal fibroblasts. We demonstrated that UVA selectively activates p38 MAPK with no effect on extracellular-regulated kinases (ERK1-ERK2) or JNK-SAPK (cJun NH2-terminal kinase-stress-activated protein kinase) activities. We then investigated the signaling pathway used by UVA to activate p38 MAPK. L-Histidine and sodium azide had an inhibitory effect on UVA activation of p38 MAPK, pointing to a role of singlet oxygen in transduction of the UVA effect. Afterward, using prolonged cell treatments with growth factors to desensitize their signaling pathways or suramin to block growth factor receptors, we demonstrated that UVA signaling pathways shared elements with growth factor signaling pathways. In addition, using emetine (a translation inhibitor altering ribosome functioning) we detected the involvement of ribotoxic stress in p38 MAPK activation by UVA. Our observations suggest that p38 activation by UVA in dermal fibroblasts involves singlet oxygen-dependent activation of ligand-receptor signaling pathways or ribotoxic stress mechanism (or both). Despite the activation of these two distinct signaling mechanisms, the selective activation of p38 MAPK suggests a critical role of this kinase in the effects of UVA radiation.

  1. p38 MAP kinase-dependent regulation of the expression level and subcellular distribution of heterogeneous nuclear ribonucleoprotein A1 and its involvement in cellular senescence in normal human fibroblasts

    PubMed Central

    Shimada, Naoko; Rios, Ileana; Moran, Heriberto; Sayers, Brendan; Hubbard, Karen

    2010-01-01

    Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a RNA binding protein that plays important role in the biogenesis of mRNA, such as alternative splicing and mRNA stability. We have previously demonstrated that hnRNP A1 has diminished protein levels and shows cytoplasmic accumulation in senescent human diploid fibroblasts. Recent reports showed that p38 MAP kinase (p38 MAPK), a member of the MAP kinase family is necessary and sufficient for the cytoplasmic accumulation of hnRNP A1 by stress stimuli such as osmotic shock. p38 MAP kinase has been shown to be involved in cell proliferation and the induction of senescence in response to extracellular stimuli. However, the relationship between hnRNP A1 and p38 MAPK and the roles of hnRNP A1 in cellular senescence have not yet been elucidated. Here we show that hnRNP A1 forms a complex with phospho-p38 MAPK in vivo. Inhibition of p38 MAPK activity with SB203580 elevated hnRNP A1 protein levels and prohibited the cytoplasmic accumulation of the protein, but not hnRNP A2, in senescent cells. The phosphorylation level of hnRNP A1 was elevated in senescent cells. Reduction of hnRNP A1 and A2 levels by siRNA transfection induced a senescence-like morphology and elevated the level of F-actin, a marker of senescence. These results suggest that the expression levels and subcellular distribution of hnRNP A1 are regulated in a p38 MAPK-dependent manner, probably via its phosphorylation. Our results also suggest that hnRNP A2 in addition to hnRNP A1 may play a role in establishing the senescence phenotype. PMID:19430204

  2. LZAP Inhibits p38 MAPK (p38) Phosphorylation and Activity by Facilitating p38 Association with the Wild-Type p53 Induced Phosphatase 1 (WIP1)

    PubMed Central

    An, Hanbing; Lu, Xinyuan; Liu, Dan; Yarbrough, Wendell G.

    2011-01-01

    LZAP (Cdk5rap3, C53) is a putative tumor suppressor that inhibits RelA, Chk1 and Chk2 and activates p53. LZAP is lost in a portion of human head and neck squamous cell carcinoma and experimental loss of LZAP expression is associated with enhanced invasion, xenograft tumor growth and angiogenesis. p38 MAPK can increase or decrease proliferation and cell death depending on cellular context. LZAP has no known enzymatic activity, implying that its biological functions are likely mediated by its protein-protein interactions. To gain further insight into LZAP activities, we searched for LZAP-associated proteins (LAPs). Here we show that the LZAP binds p38, alters p38 cellular localization, and inhibits basal and cytokine-stimulated p38 activity. Expression of LZAP inhibits p38 phosphorylation in a dose-dependent fashion while loss of LZAP enhances phosphorylation and activation with resultant phosphorylation of p38 downstream targets. Mechanistically, the ability of LZAP to alter p38 phosphorylation depended, at least partially, on the p38 phosphatase, Wip1. Expression of LZAP increased both LZAP and Wip1 binding to p38. Taken together, these data suggest that LZAP activity includes inhibition of p38 phosphorylation and activation. PMID:21283629

  3. LZAP inhibits p38 MAPK (p38) phosphorylation and activity by facilitating p38 association with the wild-type p53 induced phosphatase 1 (WIP1).

    PubMed

    An, Hanbing; Lu, Xinyuan; Liu, Dan; Yarbrough, Wendell G

    2011-01-24

    LZAP (Cdk5rap3, C53) is a putative tumor suppressor that inhibits RelA, Chk1 and Chk2 and activates p53. LZAP is lost in a portion of human head and neck squamous cell carcinoma and experimental loss of LZAP expression is associated with enhanced invasion, xenograft tumor growth and angiogenesis. p38 MAPK can increase or decrease proliferation and cell death depending on cellular context. LZAP has no known enzymatic activity, implying that its biological functions are likely mediated by its protein-protein interactions. To gain further insight into LZAP activities, we searched for LZAP-associated proteins (LAPs). Here we show that the LZAP binds p38, alters p38 cellular localization, and inhibits basal and cytokine-stimulated p38 activity. Expression of LZAP inhibits p38 phosphorylation in a dose-dependent fashion while loss of LZAP enhances phosphorylation and activation with resultant phosphorylation of p38 downstream targets. Mechanistically, the ability of LZAP to alter p38 phosphorylation depended, at least partially, on the p38 phosphatase, Wip1. Expression of LZAP increased both LZAP and Wip1 binding to p38. Taken together, these data suggest that LZAP activity includes inhibition of p38 phosphorylation and activation.

  4. Early events in the induction of apoptosis in ovarian carcinoma cells by CD437: activation of the p38 MAP kinase signal pathway.

    PubMed

    Holmes, William F; Soprano, Dianne Robert; Soprano, Kenneth J

    2003-09-25

    Retinoids have great potential in the areas of cancer therapy and chemoprevention. 6-[3-(1-admantyl)]-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) is a conformationally restricted synthetic retinoid that has been reported to induce growth arrest and apoptosis in ovarian tumor cell lines but the entire mechanism for apoptotic induction has not been fully defined. We set out to identify the early events of CD437-induced apoptosis of the CA-OV-3 cell line and determine if these occur in a CA-OV-3 cell line resistant to CD437 (CA-CD437R). Using inhibitors for the MAP kinase cascade, we determined that MEK and p38 inhibitors could block CD437-induced apoptosis of the CA-OV-3 cell line. Moreover, treatment of CA-OV-3 and CA-CD437R cells with CD437 resulted in increased phosphorylation and activity of p38 independent of caspase-3 activation. Furthermore, p38 induced the phosphorylation of MEF2 in both CA-OV-3 and CA-CD437R cells after CD437 treatment. Finally, GFP-TR3 protein translocated to the cytosol and associated with mitochondria in both cell lines in response to CD437 treatment. This leads to depolarization of mitochondria and subsequent induction of apoptosis only in CA-OV-3 cells. These results identify a number of initial molecular events in the induction of apoptosis by CD437 in CA-OV-3 cells and demonstrate that the alteration in CA-CD437R cells, which results in resistance to CD437 maps downstream of these early events after TR3 translocation but prior to mitochondrial depolarization.

  5. Salvianolic Acid B Inhibits ERK and p38 MAPK Signaling in TGF-β1-Stimulated Human Hepatic Stellate Cell Line (LX-2) via Distinct Pathways

    PubMed Central

    Lv, Zhigang; Xu, Lieming

    2012-01-01

    Salvianolic acid B (SA-B) is water-soluble component of Radix Salvia miltiorrhiza. The previous work indicated that SA-B can inhibit MAPK and Smad signaling in activated hepatic stellate cells (HSCs) to perform anti-fibrotic activity Lv et al. 2010. However, some studies have shown that there is cross-talk between MAPK and Smad in certain cell types. Thus, the anti-fibrotic action of SA-B may be through the cross-talk. In order to clarify the mechanism of SA-B further, we knocked down Smad in LX-2 cells (SRV4) via RNAi, and then added TGF-β1, and PD98059 or SB203580 and SA-B. The levels of p-MEK and p-p38 were inhibited by SA-B in SRV4 independent of TGF-β1. The expression of Col I and α-SMA in SRV4 could be reduced by SA-B independent TGF-β1. SB203580 had not significant effect on p-MEK in SRV4 stimulated by TGF-β1. The levels of p-MEK in SRV4 were not increased significantly after TGF-β1 stimulation. PD98059 had no effect on the levels of p-p38 in SRV4 irrespective of TGF-β1. In conclusion, SA-B inhibits the synthesis of Col I in LX-2 cells independent of TGF-β1 stimulation, and the anti-fibrotic effect of SA-B is due to direct inhibition of p38 signaling and inhibition the cross-talk of Smad to ERK signaling. PMID:21860657

  6. Icariin Attenuates High-cholesterol Diet Induced Atherosclerosis in Rats by Inhibition of Inflammatory Response and p38 MAPK Signaling Pathway.

    PubMed

    Hu, Yanwu; Sun, Bo; Liu, Kai; Yan, Mengtong; Zhang, Yang; Miao, Chunsheng; Ren, Liqun

    2016-02-01

    Icariin is a flavonoid isolated from the traditional Chinese herbal medicine Epimedium brevicornum Maxim and has been reported to be effective for the treatment of a variety of cardiovascular diseases. The aim of the present study was to investigate the effect and mechanism of icariin on atherosclerosis (AS) using a high-cholesterol diet (HCD)-induced rat model. Seventy male Wistar rats were divided into five groups: 20 in the control group, 20 in the AS group, 10 in the simvastatin group, 10 in the low-dose icariin group, and 10 in the high-dose icariin group. A HCD and vitamin D3 were administered to establish AS rat model. The five groups of rats received daily intragastric administration of normal saline, simvastatin, or icariin (30 mg/kg/d, 60 mg/kg/d) for 4 weeks. The levels of blood lipids, superoxide dismutase (SOD), and malonaldehyde (MDA) were measured. The mRNA levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α were analyzed by real-time RT-PCR, and the serum levels of IL-6 and TNF-α were measured using ELISA kit. In addition, the expression of phosphorylated p38 (p-p38) MAPK was detected by Western blot analysis. The results indicated that AS rat models were successfully constructed. In the AS group, the levels of blood lipids including total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), and MDA were significantly increased, while high-density lipoprotein-cholesterol (HDL-C) and SOD were significantly decreased, compared with those in the control group. However, icariin succeeded in improving these biochemical parameters towards the normal values in the control group. In the simvastatin group and the icariin groups, the serum levels of IL-6 and TNF-α and the related tissue mRNA levels, as well as the expression of p-p38 MAPK, were markedly reduced compared with the AS group. In conclusion, the present study indicated that icariin inhibited the HCD-induced dyslipidemia in rats, the mechanisms may be

  7. Recombinant CC16 protein inhibits the production of pro-inflammatory cytokines via NF-κB and p38 MAPK pathways in LPS-activated RAW264.7 macrophages.

    PubMed

    Pang, Min; Yuan, Yangyang; Wang, Dong; Li, Ting; Wang, Dan; Shi, Xiaohong; Guo, Min; Wang, Chunfang; Zhang, Xinri; Zheng, Guoping; Yu, Baofeng; Wang, Hailong

    2017-03-17

    Accumulating evidence indicates that Clara cell protein-16 (CC16) has anti-inflammatory functions, although the involved molecular pathways have not been completely elucidated. Here, we evaluated the effect of recombinant rat CC16 (rCC16) on the expression of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and IL-8 in lipopolysaccharide (LPS)-stimulated mouse macrophages (RAW264.7 cells) and explored the underlying molecular mechanisms. It was found that rCC16 inhibited LPS-induced TNF-α, IL-6, and IL-8 expression at both the messenger ribonucleicacid (mRNA) level and protein level in a concentration-dependent manner, as demonstrated by real-time reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay. Such suppressive effects were accompanied by the inhibition of transcriptional activity and the deoxyribonucleic acid binding activity of nuclear factor (NF)-κB but not activator protein (AP)-1. Western blot analysis further revealed that rCC16 inhibited the increase of nuclear NF-κB and the reduction of cytosolic NF-κB, the phosphorylation and reduction of NF-κB inhibitory protein IκBα, and the p38 mitogen-activated protein kinase (MAPK)-dependent NF-κB activation by phosphorylation at Ser276 of its p65 subunit. Furthermore, rCC16 was found to have no effect on the phosphorylation of c-Jun N-terminal kinase, c-Jun, or the nuclear translocation of c-Jun. In addition, reduction of TNF-α, IL-6, and IL-8 were reversed when the level of endogenous uteroglobin-binding protein was reduced by RNA interference in rCC16- and LPS-treated RAW264.7 cells. Our data suggest that rCC16 suppresses LPS-mediated inflammatory mediator TNF-α, IL-6, and IL-8 production by inactivating NF-κB and p38 MAPK but not AP-1 in RAW264.7 cells.

  8. miR-214 suppresses the osteogenic differentiation of bone marrow-derived mesenchymal stem cells and these effects are mediated through the inhibition of the JNK and p38 pathways

    PubMed Central

    Guo, Yongzhi; Li, Lianhua; Gao, Jie; Chen, Xiaobin; Sang, Qinghua

    2017-01-01

    In this study, we sought to investigate the expression of microRNA (miR)-214 on the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and explore the possible underlying mechanisms. We found that the overexpression of miR-214 effectively promoted the adipocyte differentiation of BMSCs in vitro, reduced alkaline phosphatase (ALP) activity and the gene expression of collagen type I (Col I), osteocalcin (OCN) and osteopontin (OPN) in the BMSCs. We further found that the overexpression of miR-214 suppressed the protein expression of fibroblast growth factor (FGF), phosphorylated c-Jun N-terminal kinase (p-JNK) and phosphorylated p38 (p-p38) in the BMSCs. The downregulation of miR-214 promoted the osteogenic differentiation of BMSCs, and increased ALP activity and Col I, OCN and OPN gene expression in the BMSCs. It also increased FGF p-JNK and p-p38 protein expression in the BMSCs. The use of JNK inhibitor (SP600125) enhanced the inhibitory effects of miR-214 overexpression on osteogenic differentiation, ALP activity, and Col I, OCN and OPN gene expression in the BMSCs. Lastly, the use of p38 inhibitor (SB202190) also enhanced the inhibitory effects of miR-214 overexpression on ALP activity, and Col I, OCN and OPN gene expression in the BMSCs. These results provide a mechanism responsible for the suppressive effects of miR-214 on the osteogenic differentiation of BMSCs involving the inhibition of the JNK and p38 pathways. PMID:27959394

  9. Non-thermal activation of the hsp27/p38MAPK stress pathway by mobile phone radiation in human endothelial cells: molecular mechanism for cancer- and blood-brain barrier-related effects.

    PubMed

    Leszczynski, Dariusz; Joenväärä, Sakari; Reivinen, Jukka; Kuokka, Reetta

    2002-05-01

    We have examined whether non-thermal exposures of cultures of the human endothelial cell line EA.hy926 to 900 MHz GSM mobile phone microwave radiation could activate stress response. Results obtained demonstrate that 1-hour non-thermal exposure of EA.hy926 cells changes the phosphorylation status of numerous, yet largely unidentified, proteins. One of the affected proteins was identified as heat shock protein-27 (hsp27). Mobile phone exposure caused a transient increase in phosphorylation of hsp27, an effect which was prevented by SB203580, a specific inhibitor of p38 mitogen-activated protein kinase (p38MAPK). Also, mobile phone exposure caused transient changes in the protein expression levels of hsp27 and p38MAPK. All these changes were non-thermal effects because, as determined using temperature probes, irradiation did not alter the temperature of cell cultures, which remained throughout the irradiation period at 37 +/- 0.3 degrees C. Changes in the overall pattern of protein phosphorylation suggest that mobile phone radiation activates a variety of cellular signal transduction pathways, among them the hsp27/p38MAPK stress response pathway. Based on the known functions of hsp27, we put forward the hypothesis that mobile phone radiation-induced activation of hsp27 may (i) facilitate the development of brain cancer by inhibiting the cytochrome c/caspase-3 apoptotic pathway and (ii) cause an increase in blood-brain barrier permeability through stabilization of endothelial cell stress fibers. We postulate that these events, when occurring repeatedly over a long period of time, might become a health hazard because of the possible accumulation of brain tissue damage. Furthermore, our hypothesis suggests that other brain damaging factors may co-participate in mobile phone radiation-induced effects.

  10. Ginsenoside Rd attenuates the inflammatory response via modulating p38 and JNK signaling pathways in rats with TNBS-induced relapsing colitis.

    PubMed

    Yang, Xiao-Lai; Guo, Tian-Kang; Wang, Yan-Hong; Huang, Yan-Hui; Liu, Xia; Wang, Xiao-Xia; Li, Wan; Zhao, Xin; Wang, Li-Ping; Yan, Shuai; Wu, Di; Wu, Yong-Jie

    2012-02-01

    In this study, we investigated the effects and the protective mechanism of ginsenoside Rd (GRd) which has been identified as one of the effective compounds from ginseng on relapsing colitis model induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats. After inducing relapsing colitis in experimental rats on two occasions by intracolonic injection of TNBS, GRd (10, 20 and 40 mg/kg) was administered to experimental colitis rats for 7 days. The inflammatory degree was assessed by macroscopic score, histology and myeloperoxidase (MPO) activity. The levels of proinflammatory cytokines, such as TNF-α, IL-1β, and IL-6 were determined by ELISA. Mitogen-activated protein kinase (MAPK) phosphorylation was analyzed by western blotting method. The results showed that GRd markedly attenuates the inflammatory response to TNBS-induced relapsing colitis, as evidenced by improved signs, increased body weight, decreased colonic weight/length ratio, reduced colonic macroscopic and microscopic damage scores, inhibited the activity of MPO, lowered proinflammatory cytokine levels and suppressed phosphorylation of p38 and JNK. The possible mechanism of protection on experimental colitis after GRd administration was that it could reduce the accumulation of leukocytes and down-regulate multiple proinflammatory cytokines through modulation of JNK and p38 activation.

  11. The newly synthesized 2-(3-hydroxy-5-methoxyphenyl)-6,7-methylenedioxyquinolin-4-one triggers cell apoptosis through induction of oxidative stress and upregulation of the p38 MAPK signaling pathway in HL-60 human leukemia cells.

    PubMed

    Cheng, Yung-Yi; Yang, Jai-Sing; Tsai, Shih-Chang; Liaw, Chih-Chuang; Chung, Jing-Gung; Huang, Li-Jiau; Lee, Kuo-Hsiung; Lu, Chi-Cheng; Chien, Hsi-Cheng; Tsuzuki, Minoru; Kuo, Sheng-Chu

    2012-10-01

    The aim of the present study was to discover the signaling pathways associated with 2-(3-hydroxy-5-methoxy-phenyl)-6,7-methylenedioxyquinolin-4-one (YYK1)-induced apoptosis in HL-60 human leukemia cells. YYK1 induced cytotoxic effects, cell morphological changes, decreased the cell number and increased reactive oxygen species (ROS) production and loss of mitochondrial membrane potential (ΔΨm) in HL-60 cells. YYK1-induced apoptosis was confirmed by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Results from colorimetric assays and western blot analysis indicated that activities of caspase-7/-3, caspase-8 and caspase-9 were increased in YYK1-treated HL-60 cells. Western blot analysis showed that the protein levels of extrinsic apoptotic proteins (Fas/CD95, FasL and FADD), intrinsic related proteins (cytochrome c, Apaf-1, AIF and Endo G), the ratio of Bax/Bcl-2 and phosphorylated p38 MAPK were increased in HL-60 cells after YYK1 treatment. Cell apoptosis was significantly reduced after pre-treatment with N-acetylcysteine (NAC; a ROS scavenger) or diphenyleneiodonium chloride (DPI; a NADPH oxidase inhibitor). Blockage of p38 MAPK signaling by SB202190 abolished YYK1-induced Fas/CD95 upregulation and apoptosis in HL-60 cells. We conclude that YYK1 induces both of extrinsic and intrinsic apoptotic pathways via ROS-mediated activation of p38 MAPK signaling in HL-60 human leukemia cells in vitro.

  12. HIV-1 Nef Induces CCL5 production in astrocytes through p38-MAPK and PI3K/Akt pathway and utilizes NF-kB, CEBP and AP-1 transcription factors

    NASA Astrophysics Data System (ADS)

    Liu, Xun; Shah, Ankit; Gangwani, Mohitkumar R.; Silverstein, Peter S.; Fu, Mingui; Kumar, Anil

    2014-03-01

    The prevalence of HIV-associated neurocognitive disorders (HAND) remains high in patients infected with HIV-1. The production of pro-inflammatory cytokines by astrocytes/microglia exposed to viral proteins is thought to be one of the mechanisms leading to HIV-1- mediated neurotoxicity. In the present study we examined the effects of Nef on CCL5 induction in astrocytes. The results demonstrate that CCL5 is significantly induced in Nef-transfected SVGA astrocytes. To determine the mechanisms responsible for the increased CCL5 caused by Nef, we employed siRNA and chemical antagonists. Antagonists of NF-κB, PI3K, and p38 significantly reduced the expression levels of CCL5 induced by Nef transfection. Furthermore, specific siRNAs demonstrated that the Akt, p38MAPK, NF-κB, CEBP, and AP-1 pathways play a role in Nef-mediated CCL5 expression. The results demonstrated that the PI3K/Akt and p38 MAPK pathways, along with the transcription factors NF-κB, CEBP, and AP-1, are involved in Nef-induced CCL5 production in astrocytes.

  13. Brief Glutamine Pretreatment Increases Alveolar Macrophage CD163/Heme Oxygenase-1/p38-MAPK Dephosphorylation Pathway and Decreases Capillary Damage but Not Neutrophil Recruitment in IL-1/LPS-Insufflated Rats

    PubMed Central

    Fernandez-Bustamante, Ana; Agazio, Amanda; Wilson, Paul; Elkins, Nancy; Domaleski, Luke; He, Qianbin; Baer, Kaily A.; Moss, Angela F. D.; Wischmeyer, Paul E.; Repine, John E.

    2015-01-01

    Background Glutamine (GLN) attenuates acute lung injury (ALI) but its effect on alveolar macrophages is unknown. We hypothesized that GLN pretreatment would induce the anti-inflammatory CD163/heme oxygenase (HO)-1/p38-MAPK dephosphorylation pathway in alveolar macrophages and reduce ALI in rats insufflated with interleukin-1 (IL-1) and lipopolysaccharide (LPS). Methods Male Sprague-Dawley rats were randomized to the following groups: GLN-IL-1/LPS-, GLN+IL-1/LPS-, GLN-IL-1/LPS+, and GLN+IL-1/LPS+. GLN pretreatment was given via gavage (1g/kg L-alanyl-L-glutamine) daily for 2 days. ALI was subsequently induced by insufflating 50ng IL-1 followed by 5mg/kg E.coli LPS. After 24h, bronchoalveolar lavage (BAL) protein, lactate dehydrogenase (LDH) and neutrophil concentrations were analyzed. BAL alveolar macrophage CD163+ expression, HO-1 and p38-MAPK concentrations were measured, as well as alveolar macrophage tumor necrosis factor (TNF)-α and interleukin (IL)-10 concentrations. Histology and immunofluorescence studies were also performed. Results Following IL-1/LPS insufflation, GLN pretreated rats had significantly decreased BAL protein and LDH concentrations, but not BAL neutrophil counts, compared to non-GLN pretreated rats. The number of alveolar macrophages and the number of CD163+ macrophages were significantly increased in GLN pretreated IL-1/LPS-insufflated rats compared to non-GLN pretreated, IL-1/LPS-insufflated rats. GLN pretreatment before IL-1/LPS also significantly increased HO-1 concentrations and dephosphorylated p38-MAPK levels but not cytokine levels in alveolar macrophages. Immunofluorescence localized CD163 and HO-1 in alveolar macrophages. Conclusion Short-term GLN pretreatment activates the anti-inflammatory CD163/HO-1/p38-MAPK dephosphorylation pathway of alveolar macrophages and decreases capillary damage but not neutrophil recruitment in IL-1/LPS-insufflated rats. PMID:26147379

  14. Activin A induces skeletal muscle catabolism via p38β mitogen‐activated protein kinase

    PubMed Central

    Ding, Hui; Zhang, Guohua; Sin, Ka Wai Thomas; Liu, Zhelong; Lin, Ren‐Kuo; Li, Min

    2016-01-01

    Abstract Background Activation of type IIB activin receptor (ActRIIB) in skeletal muscle leads to muscle atrophy because of increased muscle protein degradation. However, the intracellular signalling mechanism that mediates ActRIIB‐activated muscle catabolism is poorly defined. Methods We investigated the role of p38β mitogen‐activated protein kinases (MAPK) in mediating ActRIIB ligand activin A‐activated muscle catabolic pathways in C2C12 myotubes and in mice with perturbation of this kinase pharmacologically and genetically. Results Treatment of C2C12 myotubes with activin A or myostatin rapidly activated p38 MAPK and its effector C/EBPβ within 1 h. Paradoxically, Akt was activated at the same time through a p38 MAPK‐independent mechanism. These events were followed by up‐regulation of ubiquitin ligases atrogin1 (MAFbx) and UBR2 (E3α‐II), as well as increase in LC3‐II, a marker of autophagosome formation, leading to myofibrillar protein loss and myotube atrophy. The catabolic effects of activin A were abolished by p38α/β MAPK inhibitor SB202190. Using small interfering RNA‐mediated gene knockdown, we found that the catabolic activity of activin A was dependent on p38β MAPK specifically. Importantly, systemic administration of activin A to mice similarly activated the catabolic pathways in vivo, and this effect was blocked by SB202190. Further, activin A failed to activate the catabolic pathways in mice with muscle‐specific knockout of p38β MAPK. Interestingly, activin A up‐regulated MuRF1 in a p38 MAPK‐independent manner, and MuRF1 did not appear responsible for activin A‐induced myosin heavy chain loss and muscle atrophy. Conclusions ActRIIB‐mediated activation of muscle catabolism is dependent on p38β MAPK‐activated signalling. PMID:27897407

  15. MicroRNA-181a Regulates Apoptosis and Autophagy Process in Parkinson’s Disease by Inhibiting p38 Mitogen-Activated Protein Kinase (MAPK)/c-Jun N-Terminal Kinases (JNK) Signaling Pathways

    PubMed Central

    Liu, Ying; Song, Yanfeng; Zhu, Xiaotun

    2017-01-01

    Background microRNA (miR)-181a has been reported to be downregulated in Parkinson’s disease (PD), but the regulatory mechanism of miR-181a on neuron apoptosis and autophagy is still poorly understood. We aimed to investigate the neuroprotective effects of miR-181a on PD in vitro. Material/Methods Human SK-N-SH neuroblastoma cells were incubated with different concentrations of 1-methyl-4-phenylpyridinium ion (MPP+) to induce the PD model. The expression of miR-181a was then analyzed. After transfection with miR-181a mimic or scramble following MPP+ treatment, the expression of autophagy protein markers (LC3II, LC3I, and Beclin 1) and p38 mitogen-activated protein kinase (MAPK)/c-Jun N-terminal kinases (JNK) signaling proteins (p-p38, p38, p-JNK, and JNK) and cell apoptosis were detected. Furthermore, the cells were transfected with miR-181a inhibitor and cultured in the presence or absence of p38 inhibitor SB203582 or JNK inhibitor SP600125, and the cell apoptosis was tested again. Results The expression of miR-181a was gradually decreased with the increase of MPP+ concentration (P<0.05, P<0.01, or P<0.001). Overexpression of miR-181a significantly decreased the LC3II/LC3I ratio, Beclin 1 expression, cell apoptosis, and the expression of p-p38 and p-JNK compared to the MPP+ + miR-181a scramble group (all P<0.05). In addition, we observed that SB203582 or SP600125 showed no effects on cell apoptosis, but the effects of miR-181a inhibitor on cell apoptosis were reversed by administration of SB203582 or SP600125 compared to the scramble group (P<0.05). Conclusions Our results suggest that miR-181a regulates apoptosis and autophagy in PD by inhibiting the p38 MAPK/JNK pathway. PMID:28365714

  16. MicroRNA-181a Regulates Apoptosis and Autophagy Process in Parkinson's Disease by Inhibiting p38 Mitogen-Activated Protein Kinase (MAPK)/c-Jun N-Terminal Kinases (JNK) Signaling Pathways.

    PubMed

    Liu, Ying; Song, Yanfeng; Zhu, Xiaotun

    2017-04-02

    BACKGROUND microRNA (miR)-181a has been reported to be downregulated in Parkinson's disease (PD), but the regulatory mechanism of miR-181a on neuron apoptosis and autophagy is still poorly understood. We aimed to investigate the neuroprotective effects of miR-181a on PD in vitro. MATERIAL AND METHODS Human SK-N-SH neuroblastoma cells were incubated with different concentrations of 1-methyl-4-phenylpyridinium ion (MPP+) to induce the PD model. The expression of miR-181a was then analyzed. After transfection with miR-181a mimic or scramble following MPP+ treatment, the expression of autophagy protein markers (LC3II, LC3I, and Beclin 1) and p38 mitogen-activated protein kinase (MAPK)/c-Jun N-terminal kinases (JNK) signaling proteins (p-p38, p38, p-JNK, and JNK) and cell apoptosis were detected. Furthermore, the cells were transfected with miR-181a inhibitor and cultured in the presence or absence of p38 inhibitor SB203582 or JNK inhibitor SP600125, and the cell apoptosis was tested again. RESULTS The expression of miR-181a was gradually decreased with the increase of MPP+ concentration (P<0.05, P<0.01, or P<0.001). Overexpression of miR-181a significantly decreased the LC3II/LC3I ratio, Beclin 1 expression, cell apoptosis, and the expression of p-p38 and p-JNK compared to the MPP+ + miR-181a scramble group (all P<0.05). In addition, we observed that SB203582 or SP600125 showed no effects on cell apoptosis, but the effects of miR-181a inhibitor on cell apoptosis were reversed by administration of SB203582 or SP600125 compared to the scramble group (P<0.05). CONCLUSIONS Our results suggest that miR-181a regulates apoptosis and autophagy in PD by inhibiting the p38 MAPK/JNK pathway.

  17. Telmisartan, a possible PPAR-δ agonist, reduces TNF-α-stimulated VEGF-C production by inhibiting the p38MAPK/HSP27 pathway in human proximal renal tubular cells.

    PubMed

    Kimura, Hideki; Mikami, Daisuke; Kamiyama, Kazuko; Sugimoto, Hidehiro; Kasuno, Kenji; Takahashi, Naoki; Yoshida, Haruyoshi; Iwano, Masayuki

    2014-11-14

    Vascular endothelial growth factor-C (VEGF-C) is a main inducer of inflammation-associated lymphangiogenesis in various inflammatory disorders including chronic progressive kidney diseases, for which angiotensin II receptor type 1 blockers (ARBs) are widely used as the main treatment. Although proximal renal tubular cells may affect the formation of lymphatic vessels in the interstitial area by producing VEGF-C, the molecular mechanisms of VEGF-C production and its manipulation by ARB have not yet been examined in human proximal renal tubular epithelial cells (HPTECs). In the present study, TNF-α dose-dependently induced the production of VEGF-C in HPTECs. The TNF-α-induced production of VEGF-C was mediated by the phosphorylation of p38MAPK and HSP27, but not by that of ERK or NFkB. Telmisartan, an ARB that can activate the peroxisome proliferator-activated receptor (PPAR), served as a PPAR-δ activator and reduced the TNF-α-stimulated production of VEGF-C. This reduction was partially attributed to a PPAR-δ-dependent decrease in p38MAPK phosphorylation. Our results indicate that TNF-α induced the production of VEGF-C in HPTECs by activating p38MAPK/HSP27, and this was partially inhibited by telmisartan in a PPAR-δ dependent manner. These results provide a novel insight into inflammation-associated lymphangiogenesis.

  18. Comparative study of p38 MAPK signal transduction pathway of peripheral blood mononuclear cells from patients with coal-combustion-type fluorosis with and without high hair selenium levels.

    PubMed

    Chen, Qun; Wang, Zhilun; Xiong, Yongmin; Zou, Xiuzhen; Liu, Zhengwen

    2010-09-01

    Coal-combustion-type fluorosis has only been reported in China and its pathogenesis has not been fully understood. Fluoride causes chronic toxic effects and selenium modulates cellular activities through signal transduction in human cells. The present study enrolled three groups of subjects with well-defined serum and urine fluoride and hair selenium: high fluoride+high selenium group, high fluoride group and normal control group. The expressions of p38, NF-kB p65, caspase-3 and p53 genes at both protein and mRNA levels in peripheral blood mononuclear cells (PBMCs) were determined by Western blotting and quantitative real-time RT-PCR, respectively. The results showed that the expressions of p38, NF-kB p65, and caspase-3 protein in high fluoride group were higher than those in the other two groups. The mRNA level of NF-kB p65 and caspase-3 was significantly higher in high fluoride+high selenium group than control and lower than high fluoride group. The mRNA and protein level of p53 was significantly higher in high fluoride+high selenium group than that in other two groups. These results suggest that selenium may influence the protein and gene expression associated with p38 signal transduction pathway and up-regulate p53 expression in PBMCs from patients with coal-combustion-type fluorosis.

  19. Graphene quantum dots induce apoptosis, autophagy, and inflammatory response via p38 mitogen-activated protein kinase and nuclear factor-κB mediated signaling pathways in activated THP-1 macrophages.

    PubMed

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

    2015-01-02

    The biomedical application of graphene quantum dots (GQDs) is a new emerging area. However, their safety data are still in scarcity to date. Particularly, the effect of GQDs on the immune system remains unknown. This study aimed to elucidate the interaction of GQDs with macrophages and the underlying mechanisms. Our results showed that GQDs slightly affected the cell viability and membrane integrity of macrophages, whereas GQDs significantly increased reactive oxygen species (ROS) generation and apoptotic and autophagic cell death with an increase in the expression level of Bax, Bad, caspase 3, caspase 9, beclin 1, and LC3-I/II and a decrease in that of Bcl-2. Furthermore, low concentrations of GQDs significantly increased the expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-8, whereas high concentrations of GQDs elicited opposite effects on the cytokines production. SB202190, a selective inhibitor of p38 mitogen-activated protein kinase (MAPK), abolished the cytokine-inducing effect of GQDs in macrophages. Moreover, GQDs significantly increased the phosphorylation of p38 MAPK and p65, and promoted the nuclear translocation of nuclear factor-κB (NF-κB). Taken together, these results show that GQDs induce ROS generation, apoptosis, autophagy, and inflammatory response via p38MAPK and NF-κB mediated signaling pathways in THP-1 activated macrophages.

  20. Depurinized milk downregulates rat thymus MyD88/Akt/p38 function, NF-κB-mediated inflammation, caspase-1 activity but not the endonuclease pathway: in vitro/in vivo study

    PubMed Central

    Kocic, Gordana; Veljkovic, Andrej; Kocic, Hristina; Colic, Miodrag; Mihajlovic, Dusan; Tomovic, Katarina; Stojanovic, Svetlana; Smelcerovic, Andrija

    2017-01-01

    The aim of this study was the evaluation of 15 days dietary regimen of depurinized (DP) milk (obtained using our patented technological procedures) or 1.5% fat UHT milk instead of standard chow diet, on rat thymus and bone marrow MyD88/Akt/p38, NF-κB, caspase-1 and endonuclease pathways, in relation to peripheral blood cell composition. To determine whether the reduced mass of the thymus is a consequence of the direct effect of DP/UHT milk on apoptosis of thymocytes, in vitro Annexin-V-FITC/PI assay was performed. Significant decreases in the thymus wet weight, thymocyte MyD88, Akt-1/phospho-Akt-1 kinase, p38/phospho-p38, NF-κB, caspase-1 activity and CD4+/CD8+ antigen expression were obtained, especially in the DP milk group. The activity of thymocyte alkaline and acid DNase increased in the DP but not in the UHT milk group. The level of IL-6 significantly decreased in DP milk treated group, while the level of total TGF-β and IL-6 increased in UHT milk group. Significant differences in hematological parameters were obtained in commercial milk fed group. Observed results about prevention of experimental diabetes in DP pretreated groups may suggest that purine compounds, uric acid and other volatile toxic compounds of commercial milk may suppress oral tolerance, probably via IL-6 and TGF-β cytokine effects. PMID:28176796

  1. Resveratrol attenuates ICAM-1 expression and monocyte adhesiveness to TNF-α-treated endothelial cells: evidence for an anti-inflammatory cascade mediated by the miR-221/222/AMPK/p38/NF-κB pathway

    PubMed Central

    Liu, Chen-Wei; Sung, Hsin-Ching; Lin, Shu-Rung; Wu, Chun-Wei; Lee, Chiang-Wen; Lee, I.-Ta; Yang, Yi-Fan; Yu, I-Shing; Lin, Shu-Wha; Chiang, Ming-Hsien; Liang, Chan-Jung; Chen, Yuh-Lien

    2017-01-01

    Resveratrol, an edible polyphenolic phytoalexin, improves endothelial dysfunction and attenuates inflammation. However, the mechanisms have not been thoroughly elucidated. Therefore, we investigated the molecular basis of the effects of resveratrol on TNF-α-induced ICAM-1 expression in HUVECs. The resveratrol treatment significantly attenuated the TNF-α-induced ICAM-1 expression. The inhibition of p38 phosphorylation mediated the reduction in ICAM-1 expression caused by resveratrol. Resveratrol also decreased TNF-α-induced IκB phosphorylation and the phosphorylation, acetylation, and translocation of NF-κB p65. Moreover, resveratrol induced the AMPK phosphorylation and the SIRT1 expression in TNF-α-treated HUVECs. Furthermore, TNF-α significantly suppressed miR-221/-222 expression, which was reversed by resveratrol. miR-221/-222 overexpression decreased p38/NF-κB and ICAM-1 expression, which resulted in reduced monocyte adhesion to TNF-α-treated ECs. In a mouse model of acute TNF-α-induced inflammation, resveratrol effectively attenuated ICAM-1 expression in the aortic ECs of TNF-α-treated wild-type mice. These beneficial effects of resveratrol were lost in miR-221/222 knockout mice. Our data showed that resveratrol counteracted the TNF-α-mediated reduction in miR-221/222 expression and decreased the TNF-α-induced activation of p38 MAPK and NF-κB, thereby suppressing ICAM-1 expression and monocyte adhesion. Collectively, our results show that resveratrol attenuates endothelial inflammation by reducing ICAM-1 expression and that the protective effect was mediated partly through the miR-221/222/AMPK/p38/NF-κB pathway. PMID:28338009

  2. Strigolactone analogues induce apoptosis through activation of p38 and the stress response pathway in cancer cell lines and in conditionally reprogrammed primary prostate cancer cells.

    PubMed

    Pollock, Claire B; McDonough, Sara; Wang, Victor S; Lee, Hyojung; Ringer, Lymor; Li, Xin; Prandi, Cristina; Lee, Richard J; Feldman, Adam S; Koltai, Hinanit; Kapulnik, Yoram; Rodriguez, Olga C; Schlegel, Richard; Albanese, Christopher; Yarden, Ronit I

    2014-03-30

    Strigolactones are a novel class of plant hormones produced in roots and regulate shoot and root development. We have previously shown that synthetic strigolactone analogues potently inhibit growth of breast cancer cells and breast cancer stem cells. Here we show that strigolactone analogues inhibit the growth and survival of an array of cancer-derived cell lines representing solid and non-solid cancer cells including: prostate, colon, lung, melanoma, osteosarcoma and leukemic cell lines, while normal cells were minimally affected. Treatment of cancer cells with strigolactone analogues was hallmarked by activation of the stress-related MAPKs: p38 and JNK and induction of stress-related genes; cell cycle arrest and apoptosis evident by increased percentages of cells in the sub-G1 fraction and Annexin V staining. In addition, we tested the response of patient-matched conditionally reprogrammed primary prostate normal and cancer cells. The tumor cells exhibited significantly higher sensitivity to the two most potent SL analogues with increased apoptosis confirmed by PARP1 cleavage compared to their normal counterpart cells. Thus, Strigolactone analogues are promising candidates for anticancer therapy by their ability to specifically induce cell cycle arrest, cellular stress and apoptosis in tumor cells with minimal effects on growth and survival of normal cells.

  3. Protective Effect of D-Limonene against Oxidative Stress-Induced Cell Damage in Human Lens Epithelial Cells via the p38 Pathway

    PubMed Central

    Bai, Jie; Zheng, Yi; Wang, Gang; Liu, Ping

    2016-01-01

    Oxidative stress, as mediated by ROS, is a significant factor in initiating the development of age-associated cataracts; D-limonene is a common natural terpene with powerful antioxidative properties which occurs naturally in a wide variety of living organisms. It has been shown to have antioxidant effect; we found that D-limonene can effectively prevent the oxidative damage caused by H2O2 and propose that the main mechanism underlying the inhibitory effects of D-limonene is the inhibition of HLECs apoptosis. In the present study, we used confocal-fluorescence microscopy, flow cytometry analysis, Hoechst staining, H2DCFDA staining, transmission electron microscopy, and immunoblot analysis; the results revealed that slightly higher concentrations of D-limonene (125–1800 μM) reduced the H2O2-induced ROS generation and inhibited the H2O2-induced caspase-3 and caspase-9 activation and decreased the Bcl-2/Bax ratio. Furthermore, it inhibited H2O2-induced p38 MAPK phosphorylation. Thus, we conclude that D-limonene could effectively protect HLECs from H2O2-induced oxidative stress and that its antioxidative effect is significant, thereby increasing the cell survival rate. PMID:26682012

  4. Simultaneous activation of p38 and JNK by arachidonic acid stimulates the cytosolic phospholipase A2-dependent synthesis of lipid droplets in human monocytes

    PubMed Central

    Guijas, Carlos; Pérez-Chacón, Gema; Astudillo, Alma M.; Rubio, Julio M.; Gil-de-Gómez, Luis; Balboa, María A.; Balsinde, Jesús

    2012-01-01

    Exposure of human peripheral blood monocytes to free arachidonic acid (AA) results in the rapid induction of lipid droplet (LD) formation by these cells. This effect appears specific for AA in that it is not mimicked by other fatty acids, whether saturated or unsaturated. LDs are formed by two different routes: (i) the direct entry of AA into triacylglycerol and (ii) activation of intracellular signaling, leading to increased triacylglycerol and cholesteryl ester formation utilizing fatty acids coming from the de novo biosynthetic route. Both routes can be dissociated by the arachidonyl-CoA synthetase inhibitor triacsin C, which prevents the former but not the latter. LD formation by AA-induced signaling predominates, accounting for 60–70% of total LD formation, and can be completely inhibited by selective inhibition of the group IVA cytosolic phospholipase A2α (cPLA2α), pointing out this enzyme as a key regulator of AA-induced signaling. LD formation in AA-treated monocytes can also be blocked by the combined inhibition of the mitogen-activated protein kinase family members p38 and JNK, which correlates with inhibition of cPLA2α activation by phosphorylation. Collectively, these results suggest that concomitant activation of p38 and JNK by AA cooperate to activate cPLA2α, which is in turn required for LD formation possibly by facilitating biogenesis of this organelle, not by regulating neutral lipid synthesis. PMID:22949356

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

    PubMed

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

    2016-03-01

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

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

    PubMed

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

    2016-06-08

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

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

    PubMed

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

    2014-10-01

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

  8. Γ-Ionizing radiation-induced activation of the EGFR-p38/ERK-STAT3/CREB-1-EMT pathway promotes the migration/invasion of non-small cell lung cancer cells and is inhibited by podophyllotoxin acetate.

    PubMed

    Cho, Jeong Hyun; Hong, Wan Gi; Jung, Yu-Jin; Lee, Jaeseok; Lee, Eunah; Hwang, Sang-Gu; Um, Hong-Duck; Park, Jong Kuk

    2016-06-01

    Here, we report a new intracellular signaling pathway involved in γ-ionizing radiation (IR)-induced migration/invasion and show that podophyllotoxin acetate (PA) inhibits the IR-induced invasion and migration of A549 cells (a non-small cell lung cancer (NSCLC) cell line). Our results revealed that IR increased the invasion/migration of A549 cells, and this effect was decreased by 10 nM PA treatment. PA also inhibited the expressions/activities of matrix metalloprotase (MMP) -2, MMP-9, and vimentin, suggesting that PA could block the IR-induced epithelial-mesenchymal transition (EMT). The IR-induced increases in invasion/migration were associated with the activation of EGFR-AKT, and PA inhibited this effect. P38 and p44/42 ERK were also involved in IR-induced invasion/migration, and combined treatments with PA plus inhibitors of each MAPK synergistically blocked this invasion/migration. In terms of transcription factors (TFs), IR-induced increases in cyclic AMP response element-binding protein-1 (CREB-1) and signal transducer and activator of transcription 3 (STAT3) increased invasion/migration and EMT. PA also inhibited these transcription factors and then blocked IR-induced invasion/migration. Collectively, these results indicate that IR induces cancer cell invasion/migration by activating the EGFR-p38/ERK-CREB-1/STAT3-EMT pathway and that PA blocks this pathway to inhibit IR-induced invasion/migration.

  9. Microplastic Size-Dependent Toxicity, Oxidative Stress Induction, and p-JNK and p-p38 Activation in the Monogonont Rotifer (Brachionus koreanus).

    PubMed

    Jeong, Chang-Bum; Won, Eun-Ji; Kang, Hye-Min; Lee, Min-Chul; Hwang, Dae-Sik; Hwang, Un-Ki; Zhou, Bingsheng; Souissi, Sami; Lee, Su-Jae; Lee, Jae-Seong

    2016-08-16

    In this study, we evaluated accumulation and adverse effects of ingestion of microplastics in the monogonont rotifer (Brachionus koreanus). The dependence of microplastic toxicity on particle size was investigated by measuring several in vivo end points and studying the ingestion and egestion using 0.05-, 0.5-, and 6-μm nonfunctionalized polystyrene microbeads. To identify the defense mechanisms activated in response to microplastic exposure, the activities of several antioxidant-related enzymes and the phosphorylation status of mitogen-activated protein kinases (MAPKs) were determined. Exposure to polystyrene microbeads of all sizes led to significant size-dependent effects, including reduced growth rate, reduced fecundity, decreased lifespan and longer reproduction time. Rotifers exposed to 6-μm fluorescently labeled microbeads exhibited almost no fluorescence after 24 h, while rotifers exposed to 0.05- and 0.5-μm fluorescently labeled microbeads displayed fluorescence until 48 h, suggesting that 6-μm microbeads are more effectively egested from B. koreanus than 0.05- or 0.5-μm microbeads. This observation provides a potential explanation for our findings that microbead toxicity was size-dependent and smaller microbeads were more toxic. In vitro tests revealed that antioxidant-related enzymes and MAPK signaling pathways were significantly activated in response to microplastic exposure in a size-dependent manner.

  10. p38 MAPK Signaling in Osteoblast Differentiation

    PubMed Central

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

    2016-01-01

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

  11. Saccharomyces cerevisiae Modulates Immune Gene Expressions and Inhibits ETEC-Mediated ERK1/2 and p38 Signaling Pathways in Intestinal Epithelial Cells

    PubMed Central

    Zanello, Galliano; Berri, Mustapha; Dupont, Joëlle; Sizaret, Pierre-Yves; D'Inca, Romain

    2011-01-01

    Background Enterotoxigenic Escherichia coli (ETEC) infections result in large economic losses in the swine industry worldwide. ETEC infections cause pro-inflammatory responses in intestinal epithelial cells and subsequent diarrhea in pigs, leading to reduced growth rate and mortality. Administration of probiotics as feed additives displayed health benefits against intestinal infections. Saccharomyces cerevisiae (Sc) is non-commensal and non-pathogenic yeast used as probiotic in gastrointestinal diseases. However, the immuno-modulatory effects of Sc in differentiated porcine intestinal epithelial cells exposed to ETEC were not investigated. Methodology/Principal Findings We reported that the yeast Sc (strain CNCM I-3856) modulates transcript and protein expressions involved in inflammation, recruitment and activation of immune cells in differentiated porcine intestinal epithelial IPEC-1 cells. We demonstrated that viable Sc inhibits the ETEC-induced expression of pro-inflammatory transcripts (IL-6, IL-8, CCL20, CXCL2, CXCL10) and proteins (IL-6, IL-8). This inhibition was associated to a decrease of ERK1/2 and p38 MAPK phosphorylation, an agglutination of ETEC by Sc and an increase of the anti-inflammatory PPAR-γ nuclear receptor mRNA level. In addition, Sc up-regulates the mRNA levels of both IL-12p35 and CCL25. However, measurement of transepithelial electrical resistance displayed that Sc failed to maintain the barrier integrity in monolayer exposed to ETEC suggesting that Sc does not inhibit ETEC enterotoxin activity. Conclusions Sc (strain CNCM I-3856) displays multiple immuno-modulatory effects at the molecular level in IPEC-1 cells suggesting that Sc may influence intestinal inflammatory reaction. PMID:21483702

  12. Raphanus sativus L. seeds prevent LPS-stimulated inflammatory response through negative regulation of the p38 MAPK-NF-κB pathway.

    PubMed

    Kook, Sung-Ho; Choi, Ki-Choon; Lee, Young-Hoon; Cho, Hyoung-Kwon; Lee, Jeong-Chae

    2014-12-01

    The seeds of Raphanus sativus L. (RSL) have long been used as anti-inflammatory traditional medicine. However, scientific bases for the purported potential of the medicine and the associated mechanisms were barely defined. This study investigated the effects of RSL seeds on lipopolysaccharide (LPS)-stimulated inflammatory responses in vitro and in vivo. Treatment with 100 μg/ml ethyl acetate fraction (REF), which was isolated from water extract of the seeds, significantly inhibited LPS-stimulated production of nitric oxide (P < 0.05), interleukin-6 (P < 0.001), and tumor necrosis factor (TNF)-α (P < 0.001) in RAW264.7 cells. Oral supplementation with 30 mg/kg REF protected mice by 90% against LPS-induced septic death and prevented the increases of serum TNF-α and interferon-γ levels in LPS-injected mice. When REF was divided into four sub-fractions (REF-F1-F4), REF-F3 showed the greatest activity to suppress LPS-stimulated production of inflammatory mediators. We subsequently isolated an active fraction from the REF-F3 and identified sinapic acid as the main constituent. The addition of 50 μg/ml active fraction markedly inhibited LPS-stimulated production of inflammatory mediators by suppressing p38 MAPK and nuclear factor-κB activation. Furthermore, supplementation with the active fraction (10 mg/kg) improved the survival rate of LPS-injected mice by 80% of the untreated control. Additional experiments revealed that sinapic acid was the active component responsible for the anti-inflammatory potential of RSL seeds. Collectively, our current results suggest that both RSL seeds and sinapic acid may be attractive materials for treating inflammatory disorders caused by endotoxins.

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

    PubMed

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

    2011-12-01

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

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

    PubMed

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

    2014-03-01

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

  15. Quercetin-3-O-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside suppresses melanin synthesis by augmenting p38 MAPK and CREB signaling pathways and subsequent cAMP down-regulation in murine melanoma cells

    PubMed Central

    Jung, Hyun Gug; Kim, Han Hyuk; Paul, Souren; Jang, Jae Yoon; Cho, Yong Hun; Kim, Hyeon Jeong; Yu, Jae Myo; Lee, Eun Su; An, Bong Jeun; Kang, Sun Chul; Bang, Byung Ho

    2015-01-01

    In this study, the effect of purified quercetin-3-O-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosid (QCGG) on melanogenesis was investigated. QCGG was isolated from the calyx of a traditional Korean medicinal herb, Persimmon (Diospyros kaki). The hypopigmentation effects of QCGG were determined by examination of cellular melanin contents, tyrosinase activity assay, cAMP assay, and Western blotting of α-MSH-stimulated B16F10 mouse melanoma cells. Our results showed that QCGG inhibited both melanin synthesis and tyrosinase activity in a concentration-dependent manner as well as significantly reduced the expression of melanogenic proteins such as microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1, tyrosinase-related protein-2, and tyrosinase. Moreover, QCGG inhibited intracellular cAMP levels, cAMP response element-binding protein (CREB), and p38 MAPK expression in α-MSH-stimulated B16F10 cells. Taken together, the suppressive effects of QCGG on melanogenesis may involve down-regulation of MITF and its downstream signaling pathway via phosphorylation of p38 MAPK and CREB along with reduced cAMP levels. These results indicate that QCGG reduced melanin synthesis by reducing expression of tyrosine and tyrosine-related proteins via extracellular signal-related protein kinase (ERK) activation, followed by down-regulation of CREB, p38, and MITF. PMID:26586997

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

    SciTech Connect

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

    2014-12-12

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

  17. P38 AND EGF RECEPTOR KINASE-MEDIATED ACTIVATION OF THE PHOSPHATIDYLINOSITOL 3-KINASE/AKT PATHWAY IS REQUIRED FOR ZN2+INDUCED CYCLOOXYGENASE-2 EXPRESSION

    EPA Science Inventory

    Cyclooxygenase 2 (COX-2) expression is induced by physiological and inflammatory stimuli. Regulation of COX-2 expression is stimulus- and cell type-specific. Exposure to Zn2+ has been associated with activation of multiple intracellular signaling pathways as well as the induction...

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

    PubMed

    Yu, Seon-Mi; Kim, Song-Ja

    2013-11-01

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

  19. Involvement of ERK1/2, p38 MAPK, and PI3K/Akt signaling pathways in the regulation of cell cycle progression by PTHrP in colon adenocarcinoma cells.

    PubMed

    Calvo, Natalia; Martín, María Julia; de Boland, Ana Russo; Gentili, Claudia

    2014-08-01

    Parathyroid hormone-related peptide (PTHrP) is distributed in most fetal and adult tissues, and its expression correlates with the severity of colon carcinoma. Recently we obtained evidence that in Caco-2 cells, a cell line from human colorectal adenocarcinoma, exogenous PTHrP increases the number of live cells, via ERK1/2, p38 MAPK, and PI3-kinase and induces the expression of cyclin D1, a cell cycle regulatory protein. In this study, we further investigated the role of PTHrP in the regulation of the cell cycle progression in these intestinal cells. Flow cytometry analysis revealed that PTHrP treatment diminishes the number of cells in the G0/G1 phase and increases the number in both S and G2/M phases. The hormone increases the expression of CDK6 and diminishes the amount of negative cell cycle regulators p27Kip1, p15INK4B, and p53. However, PTHrP does not modify the expression of cyclin D3, CDK4, and p16INK4A. In addition, inhibitors of ERK1/2 (PD98059), p38 MAPK (SB203580), and PI3Kinase (LY294002) reversed PTHrP response in Caco-2 cells. Taken together, our results suggest that PTHrP positively modulates cell cycle progression and changes the expression of proteins involved in cell cycle regulation via ERK1/2, p38 MAPK, and PI3K signaling pathways in Caco-2 cells.

  20. The D1 dopamine receptor agonist, SKF83959, attenuates hydrogen peroxide-induced injury in RGC-5 cells involving the extracellular signal-regulated kinase/p38 pathways

    PubMed Central

    Li, Guang-Yu; Li, Ting; Fan, Bin; Zheng, Yong-Chen

    2012-01-01

    Purpose Oxidative stress is widely implicated in the death of retinal ganglion cells associated with various optic neuropathies. Agonists of the dopamine D1 receptor have recently been found to be potentially neuroprotective against oxidative stress–induced injury. The goal of this study was to investigate whether SKF83959, a next-generation high-affinity D1 receptor agonist, could protect retinal ganglion cell 5 (RGC-5) cells from H2O2-induced damage and the molecular mechanism involved. Methods We examined expression of the D1 receptor in RGC-5 cells with reverse-transcription–PCR and immunoblotting and assessed neuroprotection using propidium iodide staining and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In addition, we monitored the activation and involvement of members of mitogen-activated protein kinase family, extracellular signal-regulated kinase (ERK), p38 and c-Jun NH2-terminal kinase, with western blot and specific inhibitors. Results We found that the D1 receptor was expressed in RGC-5 cells, but the sequence analysis suggested this cell line is from mouse and not rat origin. SKF83959 exhibited a remarkable neuroprotective effect on H2O2-damaged RGC-5 cells, which was blocked by the specific D1 receptor antagonist, SCH23390. ERK and p38 were activated by SKF83959, and pretreatment with their inhibitors U0126 and SB203580, respectively, significantly blunted the SKF83959-induced cytoprotection. However, the specific c-Jun NH2-terminal kinase inhibitor, SP600125, had no effect on the SKF83959-induced protection. Conclusions We conclude that SKF83959 attenuates hydrogen peroxide–induced injury in RGC-5 cells via a mechanism involving activation of the ERK and p38 pathways and the D1 receptor is a potential molecular target for developing neuroprotective drugs. PMID:23233790

  1. HGF-induced DNA synthesis in hepatocytes is suppressed by p38.

    PubMed

    Aasrum, Monica; Brusevold, Ingvild J; Christoffersen, Thoralf; Thoresen, G Hege

    2016-12-01

    Previous studies in rat hepatocytes have shown that the MEK/ERK, PI3K/Akt and p38 pathways are all involved in the activation of DNA synthesis by EGF and that sustained activation of MEK/ERK is required. Here, we show that although HGF stimulated DNA synthesis and activated signaling in the same manner as EGF, the contribution of the signaling pathways to the induction of DNA synthesis differed. While HGF-induced DNA synthesis was dependent on MEK/ERK, with no significant contribution from PI3K/Akt, p38 suppressed HGF-induced DNA synthesis. The p38 inhibitor SB203580 increased HGF-induced DNA synthesis and enhanced the phosphorylation of ERK. In contrast, SB203580 decreased EGF-induced ERK phosphorylation. This suggests that p38 has distinct effects on DNA synthesis induced by EGF and HGF. Due to differential regulation of signaling through the MEK/ERK pathway, p38 acts as an enhancer of EGF-induced DNA synthesis and as a suppressor of HGF-induced DNA synthesis.

  2. Low Dose Ultraviolet B Irradiation Increases Hyaluronan Synthesis in Epidermal Keratinocytes via Sequential Induction of Hyaluronan Synthases Has1–3 Mediated by p38 and Ca2+/Calmodulin-dependent Protein Kinase II (CaMKII) Signaling*

    PubMed Central

    Rauhala, Leena; Hämäläinen, Lasse; Salonen, Pauliina; Bart, Geneviève; Tammi, Markku; Pasonen-Seppänen, Sanna; Tammi, Raija

    2013-01-01

    Hyaluronan, a major epidermal extracellular matrix component, responds strongly to different kinds of injuries. This also occurs by UV radiation, but the mechanisms involved are poorly understood. The effects of a single ultraviolet B (UVB) exposure on hyaluronan content and molecular mass, and expression of genes involved in hyaluronan metabolism were defined in monolayer and differentiated, organotypic three-dimensional cultures of rat epidermal keratinocytes. The signals regulating the response were characterized using specific inhibitors and Western blotting. In monolayer cultures, UVB increased hyaluronan synthase Has1 mRNA already 4 h postexposure, with a return to control level by 24 h. In contrast, Has2 and Has3 were persistently elevated from 8 h onward. Silencing of Has2 and especially Has3 decreased the UVB-induced accumulation of hyaluronan. p38 and Ca2+/calmodulin-dependent protein kinase II pathways were found to be involved in the UVB-induced up-regulation of Has2 and Has3 expression, respectively, and their inhibition reduced hyaluronan deposition. However, the expressions of the hyaluronan-degrading enzymes Hyal1 and Hyal2 and the hyaluronan receptor Cd44 were also up-regulated by UVB. In organotypic cultures, UVB treatment also resulted in increased expression of both Has and Hyal genes and shifted hyaluronan toward a smaller size range. Histochemical stainings indicated localized losses of hyaluronan in the epidermis. The data show that exposure of keratinocytes to acute, low dose UVB increases hyaluronan synthesis via up-regulation of Has2 and Has3. The simultaneously enhanced catabolism of hyaluronan demonstrates the complexity of the UVB-induced changes. Nevertheless, enhanced hyaluronan metabolism is an important part of the adaptation of keratinocytes to radiation injury. PMID:23645665

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

    PubMed Central

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

    2013-01-01

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

  4. Ethanol Extracts of Fruiting Bodies of Antrodia cinnamomea Suppress CL1-5 Human Lung Adenocarcinoma Cells Migration by Inhibiting Matrix Metalloproteinase-2/9 through ERK, JNK, p38, and PI3K/Akt Signaling Pathways

    PubMed Central

    Chen, Ying-Yi; Liu, Fon-Chang; Chou, Pei-Yu; Chien, Yi-Chung; Chang, Wun-Shaing Wayne; Huang, Guang-Jhong; Wu, Chieh-Hsi; Sheu, Ming-Jyh

    2012-01-01

    Cancer metastasis is a primary cause of cancer death. Antrodia cinnamomea (A. cinnamomea), a medicinal mushroom in Taiwan, has shown antioxidant and anticancer activities. In this study, we first observed that ethanol extract of fruiting bodies of A. cinnamomea (EEAC) exerted a concentration-dependent inhibitory effect on migration and motility of the highly metastatic CL1-5 cells in the absence of cytotoxicity. The results of a gelatin zymography assay showed that A. cinnamomea suppressed the activities of matrix metalloproteinase-(MMP-) 2 and MMP-9 in a concentration-dependent manner. Western blot results demonstrated that treatment with A. cinnamomea decreased the expression of MMP-9 and MMP-2; while the expression of the endogenous inhibitors of these proteins, that is, tissue inhibitors of MMP (TIMP-1 and TIMP-2) increased. Further investigation revealed that A. cinnamomea suppressed the phosphorylation of ERK1/2, p38, and JNK1/2. A. cinnamomea also suppressed the expressions of PI3K and phosphorylation of Akt. Furthermore, treatment of CL1-5 cells with inhibitors specific for PI3K (LY 294002), ERK1/2 (PD98059), JNK (SP600125), and p38 MAPK (SB203580) decreased the expression of MMP-2 and MMP-9. This is the first paper confirming the antimigration activity of this potentially beneficial mushroom against human lung adenocarcinoma CL1-5 cancer cells. PMID:22454661

  5. Lannea coromandelica (Houtt.) Merr. Induces Heme Oxygenase 1 (HO-1) Expression and Reduces Oxidative Stress via the p38/c-Jun N-Terminal Kinase–Nuclear Factor Erythroid 2-Related Factor 2 (p38/JNK–NRF2)-Mediated Antioxidant Pathway

    PubMed Central

    Alam, Md Badrul; Kwon, Kyoo-Ri; Lee, Seok-Hyun; Lee, Sang-Han

    2017-01-01

    The leaves of Lannea coromandelica (Houtt.) Merr. are used in the Garo, Pahan, and Teli tribal communities of Bangladesh as a traditional medicinal plant to treat hepatitis, diabetes, ulcers, heart disease, and dysentery. However, there have been limited phytochemical and biological studies on the bark of L. coromandelica. This study aimed to investigate the antioxidant activities of L. coromandelica bark extract (LCBE) and the underlying mechanism using RAW 264.7 cells. The LCBE was analysed by high-pressure liquid chromatography (HPLC) to detect its key polyphenolic compounds. Various in vitro antioxidant assays were performed using RAW 264.7 cells to assess the antioxidant effects of the LCBE and to understand the underlying molecular mechanism. HPLC revealed the presence of gallic acid, (−)-epigallocatechin-3-gallate, catechin, chlorogenic acid, and caffeic acid in the LCBE. The extract showed a very potent capacity to scavenge numerous free radicals through hydrogen atom transfer and/or electron donation and also quenched cellular reactive oxygen species (ROS) generation without showing any toxicity. The LCBE was found to combat the oxidative stress by enhancing the expression, at both transcriptional and translational levels, of primary antioxidant enzymes as well as phase II detoxifying enzymes, especially heme oxygenase 1, through the upregulation of the nuclear factor erythroid 2-related factor 2 (NRF2)-mediated pathway in RAW 264.7 cells via the phosphorylation of p38 kinase and c-Jun N-terminal kinase (JNK). The LCBE exhibited strong antioxidant activities and mitigated the cellular ROS production. These results provide scientific evidence of its potential as an ideal applicant for a cost-effective, readily available, and natural phytochemical, as well as a strategy for preventing diseases associated with oxidative stress and attenuating disease progress. PMID:28146074

  6. Adrenergic regulation and diurnal rhythm of p38 mitogen-activated protein kinase phosphorylation in the rat pineal gland.

    PubMed

    Chik, C L; Mackova, M; Price, D; Ho, A K

    2004-11-01

    In this study, we investigated adrenergic and photoneural regulation of p38MAPK phosphorylation in the rat pineal gland. Norepinephrine (NE), the endogenous neurotransmitter, dose-dependently increased the levels of phosphorylated MAPK kinase 3/6 (MKK3/6) and p38MAPK in rat pinealocytes. Time-course studies showed a gradual increase in MKK3/6 and p38MAPK phosphorylation that peaked between 1 and 2 h and persisted for 4 h post NE stimulation. In cells treated with NE for 2 and 4 h, the inclusion of prazosin or propranolol reduced NE-induced MKK3/6 and p38MAPK phosphorylation, indicating involvement of both alpha- and beta-adrenergic receptors for the sustained response. Whereas treatment with dibutyryl cAMP or ionomycin mimicked the NE-induced MKK3/6 and p38MAPK phosphorylation, neither dibutyryl cGMP nor 4beta-phorbol 12-myristate 13-acetate had an effect. The NE-induced increase in MKK3/6 and p38MAPK phosphorylation was blocked by KT5720 (a protein kinase A inhibitor) and KN93 (a Ca(2+)/calmodulin-dependent kinase inhibitor), but not by KT5823 (a protein kinase G inhibitor) or calphostin C (a protein kinase C inhibitor). In animals housed under a lighting regimen with 12 h of light, MKK3/6 and p38MAPK phosphorylation increased in the rat pineal gland at zeitgeber time 18. The nocturnal increase in p38MAPK phosphorylation was blocked by exposing the animal to constant light and reduced by treatment with propranolol, a beta-adrenergic blocker. Together, our results indicate that activation of p38MAPK is under photoneural control in the rat pineal gland and that protein kinase A and intracellular Ca(2+) signaling pathways are involved in NE regulation of p38MAPK.

  7. Blocking the mitogen activated protein kinase-p38 pathway is associated with increase expression of nitric oxide synthase and higher production of nitric oxide by bovine macrophages infected with Mycobacterium avium subsp paratuberculosis.

    PubMed

    Souza, Cleverson D

    2015-03-15

    This study evaluated the role of the mitogen-activated protein kinase (MAPK)-p38 pathway in the nitric oxide synthase (iNOS) expression and nitric oxide (NO) production by bovine monocyte-derived macrophages ingesting Mycobacterium avium subsp. paratuberculosis (MAP) organisms in vitro. Bovine monocyte-derived macrophages were incubated with MAP organisms with or without a specific inhibitor of the MAPKp38 pathway and activation of the MAPKp38, interleukin - (IL) IL-10, IL-12, iNOS mRNA expression and NO production were evaluated. Incubation of macrophages with MAP organisms activates the MAPKp38 pathway at early time points post infection. Chemically inhibition of MAPKp38 before incubation of bovine macrophages with MAP resulted in increased expression of IL-12 mRNA at 2, 6 and 24h, decreased expression of IL-10 mRNA at 2, 6 and 24h and increased expression of iNOS mRNA at 2 and 6h. Nitric oxide was evaluated to indirectly determine the effects of MAPKp38 pathway on the anti-microbial activity of bovine macrophages. Incubation of bovine macrophages with MAP resulted in modest increased production of NO at 4 and 6h post infection. Pretreatment of bovine macrophages with the MAPKp38 inhibitor SB203580 before addition of MAP organisms resulted in increased production of NO at 2, 4, 6 and 24h post infection. This study expanded our knowledge of the importance of the MAPKp38 pathway in limiting an appropriate macrophage response to MAP and suggested how activation of MAPKp38 pathway may be a target of this organism to disrupt earlier antimicrobial mechanisms of macrophages. These findings raises the interesting possibility that the cellular manipulation of MAPKp38 may be useful in designing novel vaccines against MAP.

  8. Combined glutamine and arginine decrease proinflammatory cytokine production by biopsies from Crohn's patients in association with changes in nuclear factor-kappaB and p38 mitogen-activated protein kinase pathways.

    PubMed

    Lecleire, Stéphane; Hassan, Aktham; Marion-Letellier, Rachel; Antonietti, Michel; Savoye, Guillaume; Bôle-Feysot, Christine; Lerebours, Eric; Ducrotté, Philippe; Déchelotte, Pierre; Coëffier, Moïse

    2008-12-01

    Glutamine (Gln) and arginine (Arg) are conditionally essential amino acids with immunomodulatory properties. The aim of the study was to assess the effects of Gln and Arg alone or in combination on cytokine release by cultured colonic biopsies from patients with active Crohn's disease (CD). Ten consecutive patients [mean (range) age 26 (18-39) y] with active colonic CD (mean CD activity index: 383.7 +/- 129.8) were prospectively included in the study. Eight colonic biopsies were obtained via a colonoscopy and incubated during 18 h with low (physiological) or high (pharmacological) doses of Arg (0.1 or 2 mmol/L designated as Arg(low) or Arg(high), respectively) and Gln (0.6 or 10 mmol/L designated as Gln(low) or Gln(high), respectively). The concentrations of cytokines [interleukin (IL)-4, IL-10, IL-8, IL-6, tumor necrosis factor-alpha (TNFalpha), IL-1beta, interferon-gamma) were assessed by ELISA, and nitric oxide (NO) production was evaluated by Griess assay. Nuclear factor (NF)-kappaB p65 subunit, inhibitor of NFkappaB-alpha, and p38 mitogen-activated protein kinase (MAPK) were assessed by immunoblotting. Arg(high)/Gln(high) decreased the production of TNFalpha, IL-1beta, IL-8, and IL-6 (each P < 0.01). Arg(low)/Gln(high) decreased IL-6 and IL-8 production (both P < 0.01), whereas Arg(high)/Gln(low) did not affect cytokine and NO production. Arg(low)/Gln(high) and Arg(high)/Gln(high) decreased NF-kappaB p65 subunit expression, whereas p38 MAPK was decreased only by Arg(high)/Gln(high). Combined pharmacological doses of Arg and Gln decreased TNFalpha and the main proinflammatory cytokines release in active colonic CD biopsies via NF-kappaB and p38 MAPK pathways. These results could be the basis of prospective studies evaluating the effects of enteral supply of combined Arg and Gln during active CD.

  9. Protective role of sodium butyrate, a HDAC inhibitor on beta-cell proliferation, function and glucose homeostasis through modulation of p38/ERK MAPK and apoptotic pathways: study in juvenile diabetic rat.

    PubMed

    Khan, S; Jena, G B

    2014-04-25

    Type 1 diabetes (T1D) also known as juvenile diabetes is a chronic autoimmune disorder that precipitates in genetically susceptible individuals by environmental factors particularly during early age. Both genetic and epigenetic factors are implicated in the beta-cell development, proliferation, differentiation and function. Recent evidences suggested that there is a link between diabetes and histone deacetylases (HDACs), because HDAC inhibitors promote beta-cell development, proliferation and function as well as improve glucose homeostasis. Sodium butyrate (NaB) is a short chain fatty acid having HDAC inhibition activity. The present study was aimed to investigate the protective role of NaB treatment on the beta-cell proliferation, function and glucose homeostasis as well as apoptosis in juvenile diabetic rat. Diabetes was induced by single injection of STZ (60 mg/kg, i.p.) in chilled citrate buffer, while NaB (500 mg/kg/day) was administrated by i.p. route for 21 days as pre- and post-treatment schedule. Plasma glucose and insulin levels, HbA1c, glucose tolerance, apoptosis, and expression of proliferating cell nuclear antigen (PCNA), p38, p53, caspase-3, extracellular signal-regulated kinase-1/2 (ERK-1/2), forkhead box protein O1 (FOXO1) and insulin receptor substrate-1 (IRS-1) as well as histone acetylation were evaluated. NaB treatment decreased plasma glucose, HbA1c, beta-cell apoptosis and improved plasma insulin level and glucose homeostasis through HDAC inhibition and histone acetylation in diabetic animal as compared to control. NaB treatment improved the beta-cell proliferation, function and glucose homeostasis as well as reduced beta-cell apoptosis in juvenile diabetic rat by the modulation of p38/ERK MAPK and apoptotic pathway.

  10. Hyperbaric oxygen activates discoidin domain receptor 2 via tumour necrosis factor-alpha and the p38 MAPK pathway to increase vascular smooth muscle cell migration through matrix metalloproteinase 2.

    PubMed

    Shyu, Kou-Gi; Wang, Bao-Wei; Chang, Hang

    2009-04-01

    DDR2 (discoidin domain receptor 2) regulates collagen turnover mediated by SMCs (smooth muscle cells) in atherosclerosis. HBO (hyperbaric oxygen) has been used in medical practice; however, the molecular mechanism of the beneficial effects of HBO is poorly understood. Furthermore, the effect of HBO on DDR2 has not been reported previously. In the present study, we investigated the cellular and molecular mechanisms of DDR2 regulation by HBO in VSMCs (vascular SMCs). Cells were exposed to 2.5 ATA (atmosphere absolute) of oxygen in a hyperbaric chamber. DDR2 protein (3.63-fold) and mRNA (2.34-fold) expression were significantly increased after exposure to 2.5 ATA HBO for 1 h. Addition of SB203580 and p38 MAPK (mitogen-activated protein kinase) siRNA (small interfering RNA) 30 min before HBO inhibited the induction of DDR2 protein. HBO also significantly increased DNA-protein binding activity of Myc/Max. Addition of SB203580 and an anti-TNF-alpha (tumour necrosis factor-alpha) monoclonal antibody 30 min before HBO abolished the DNA-protein binding activity induced by HBO. HBO significantly increased the secretion of TNF-alpha from cultured VSMCs. Exogenous addition of TNF-alpha significantly increased DDR2 protein expression, whereas anti-TNF-alpha and anti-(TNF-alpha receptor) antibodies blocked the induction of DDR2 protein expression. HBO significantly increased VSMC migration and proliferation, whereas DDR2 siRNA inhibited the migration induced by HBO. HBO increased activated MMP2 (matrix metalloproteinase 2) protein expression, and DDR2 siRNA abolished the induction of activated MMP2 expression induced by HBO. In conclusion, HBO activates DDR2 expression in cultured rat VSMCs. HBO-induced DDR2 is mediated by TNF-alpha and at least in part through the p38 MAPK and Myc pathways.

  11. Differentiation-inducing potency of the seco-steroid JK-1624F2-2 can be increased by combination with an antioxidant and a p38MAPK inhibitor which upregulates the JNK pathway.

    PubMed

    Zhang, Jing; Posner, Gary H; Danilenko, Michael; Studzinski, George P

    2007-01-01

    Low calcemic analogs of vitamin D are candidates for differentiation therapy of human myeloid leukemias. We report here that the seco-steroid synthesized to have resistance to intracellular degradation and low calcemia-inducing activity, 1alpha-hydroxymethyl-3beta-16-ene-24,24-difluoro-25-hydroxy-vitamin D(3) (JKF), induces monocytic differentiation in four established human myeloid leukemia cell lines, HL60, U937, THP-1, NB-4, and murine myeloid leukemia cells WEHI-3B D(-). JKF has differentiation-inducing potency which is slightly lower than the physiologically active form of vitamin D, 1,25(OH)(2)vitamin D(3) (1,25D). However, simultaneous addition of carnosic acid (CA), an antioxidant, and SB20190 (SB), an inhibitor of p38MAP kinase, increases the differentiation efficiency of JKF to a level similar to the level observed when 1,25D is used in such combinations. We also show for the first time that SB inhibits the phosphorylation of MAPKAPK2, a downstream target of p38MAPK, but upregulates the phosphorylation of at least one of the isoforms of JNK (p46 JNK1) and of c-jun in all four human myeloid cell lines studied here. These studies indicate that the JNK1 pathway is positively associated with monocytic differentiation of several subtypes of myeloid leukemia cells arrested at different developmental stages. Further, since JKF is less calcemic than 1,25D, the data suggest that JKF combined with CA and SB is likely to have a therapeutic advantage over 1,25D-based experimental regimens for myeloid leukemias.

  12. Procyanidins from wild grape (Vitis amurensis) seeds regulate ARE-mediated enzyme expression via Nrf2 coupled with p38 and PI3K/Akt pathway in HepG2 cells.

    PubMed

    Bak, Min-Ji; Jun, Mira; Jeong, Woo-Sik

    2012-01-01

    Procyanidins, polymers of flavan-3-ol units, have been reported to exhibit many beneficial health effects such as antioxidant and anti-carcinogenic effects. In this study, we investigated the cancer chemopreventive properties of procyanidins from wild grape (Vitis amurensis) seeds in particular their roles in inducing phase II detoxifying/antioxidant enzymes as well as in modulating the upstream kinases. Ethanolic extract of V. amurensis seeds was fractionated with a series of organic solvents and finally separated into six fractions, F1-F6. Chemical properties of the procyanidins were analyzed by vanillin assay, BuOH-HCl test, and depolymerization with phloroglucinol followed by LC/MS analysis. The F5 had the highest procyanidin content among all the fractions and strongly induced the reporter activity of antioxidant response element as well as the protein expression of nuclear factor E2-related factor (Nrf2) in HepG2 human hepatocarcinoma cells. The procyanidin-rich F5 also strongly induced the expression of the phase II detoxifying and antioxidant enzymes such as NAD(P)H:quinone oxidoreductase1 and hemeoxygenase1. Phosphorylations of the upstream kinases such as MAPKs and PI3K/Akt were significantly increased by treatment with procyanidin fraction. In addition, the procyanidin-mediated Nrf2 expression was partly attenuated by PI3K inhibitor LY294002, and almost completely by p38 inhibitor SB202190, but neither by JNK inhibitor SP600125 nor by MEK1/2 inhibitor U0126. Taken together, the procyanidins from wild grape seeds could be used as a potential natural chemopreventive agent through Nrf2/ARE-mediated phase II detoxifying/antioxidant enzymes induction via p38 and PI3K/Akt pathway.

  13. Dehydrocostuslactone inhibits LPS-induced inflammation by p38MAPK-dependent induction of hemeoxygenase-1 in vitro and improves survival of mice in CLP-induced sepsis in vivo.

    PubMed

    Park, Eun Jung; Park, Sang Won; Kim, Hye Jung; Kwak, Jong-Hwan; Lee, Dong-Ung; Chang, Ki Churl

    2014-10-01

    We investigated the hypothesis that the administration of dehydrocostuslactone (DL), a sesquiterpene lactone found in Saussurea lappa Clarke (Compositae), might reduce organ failure and increase survival in a cecal ligation and puncture (CLP)-induced mouse model of sepsis due to HO-1 induction. Treatment of RAW264.7 cells with DL increased HO-1 expression in a time- and concentration-dependent manner, and this up-regulation of HO-1 by DL was significantly inhibited by silencing either Nrf2 and p38 or treating cells with SB203580 (a p38MAPK inhibitor), but it was not inhibited in the presence of SP600125 (an ERK inhibitor), PD98059 (a JNK inhibitor), or LY294002 (PI3K inhibitor). As expected, DL concentration dependently inhibited the expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2), and the productions of NO and PGE2 in LPS-activated cells, and these inhibitions were reversed by silencing HO-1. Most importantly, administration of DL significantly reduced mortality and reduced serum IL-1β and TNF-α and the infiltration of macrophages into liver tissues of CLP-mice. Inducible NOS expression in lung and liver tissues of CLP-mice was reduced by DL, which was reversed by the co-administration of zinc-protoporphyrin IX (ZnPPIX; a competitive inhibitor of HO-1). Our findings indicate that DL might be useful for the treatment of sepsis.

  14. Oxygen-glucose deprivation preconditioning protects neurons against oxygen-glucose deprivation/reperfusion induced injury via bone morphogenetic protein-7 mediated ERK, p38 and Smad signalling pathways.

    PubMed

    Guan, Junhong; Du, Shaonan; Lv, Tao; Qu, Shengtao; Fu, Qiang; Yuan, Ye

    2016-01-01

    Bone morphogenetic protein (BMP)-7 mediated neuroprotective effect of cerebral ischemic preconditioning (IPC) has been studied in an ischemic animal model, but the underlying cellular mechanisms have not been clearly clarified. In this study, primary cortical neurons and the SH-SY5Y cell line were used to investigate the role of BMP-7 and its downstream signals in the neuroprotective effects of oxygen-glucose deprivation preconditioning (OGDPC). Immunocytochemistry was used to detect the expression of neurofilament in neurons. MTT and lactate dehydrogenase activity assays were used to measure the cytotoxicity. Western blot was used to detect the protein expression of BMP-7 and downstream signals. BMP inhibitor, mitogen-activated protein kinase inhibitors, Smad inhibitor and siRNA of Smad 1 were used to investigate the role of corresponding signalling pathways in the OGDPC. Results showed that OGDPC-induced overexpression of BMP-7 in primary cortical neurons and SH-SY5Y cells. Both of endogenous and exogenous BMP-7 could replicate the neuroprotective effects seen in OGDPC pretreatment. In addition, extracellular regulated protein kinases, p38 and Smad signalling pathway were found to be involved in the neuroprotective effects mediated by OGDPC via BMP-7. This study primarily reveals the cellular mechanisms of the neuroprotection mediated by OGDPC, and provides evidence for better understanding of this intrinsic factor against ischemia.

  15. Khz-cp (crude polysaccharide extract obtained from the fusion of Ganoderma lucidum and Polyporus umbellatus mycelia) induces apoptosis by increasing intracellular calcium levels and activating P38 and NADPH oxidase-dependent generation of reactive oxygen species in SNU-1 cells

    PubMed Central

    2014-01-01

    Background Khz-cp is a crude polysaccharide extract that is obtained after nuclear fusion in Ganoderma lucidum and Polyporus umbellatus mycelia (Khz). It inhibits the growth of cancer cells. Methods Khz-cp was extracted by solvent extraction. The anti-proliferative activity of Khz-cp was confirmed by using Annexin-V/PI-flow cytometry analysis. Intracellular calcium increase and measurement of intracellular reactive oxygen species (ROS) were performed by using flow cytometry and inverted microscope. SNU-1 cells were treated with p38, Bcl-2 and Nox family siRNA. siRNA transfected cells was employed to investigate the expression of apoptotic, growth and survival genes in SNU-1 cells. Western blot analysis was performed to confirm the expression of the genes. Results In the present study, Khz-cp induced apoptosis preferentially in transformed cells and had only minimal effects on non-transformed cells. Furthermore, Khz-cp was found to induce apoptosis by increasing the intracellular Ca2+ concentration ([Ca2+]i) and activating P38 to generate reactive oxygen species (ROS) via NADPH oxidase and the mitochondria. Khz-cp-induced apoptosis was caspase dependent and occurred via a mitochondrial pathway. ROS generation by NADPH oxidase was critical for Khz-cp-induced apoptosis, and although mitochondrial ROS production was also required, it appeared to occur secondary to ROS generation by NADPH oxidase. Activation of NADPH oxidase was shown by the translocation of the regulatory subunits p47phox and p67phox to the cell membrane and was necessary for ROS generation by Khz-cp. Khz-cp triggered a rapid and sustained increase in [Ca2+]i that activated P38. P38 was considered to play a key role in the activation of NADPH oxidase because inhibition of its expression or activity abrogated membrane translocation of the p47phox and p67phox subunits and ROS generation. Conclusions In summary, these data indicate that Khz-cp preferentially induces apoptosis in cancer cells and that the

  16. Sodium Octanoate Modulates the Innate Immune Response of Bovine Mammary Epithelial Cells through the TLR2/P38/JNK/ERK1/2 Pathway: Implications during Staphylococcus aureus Internalization

    PubMed Central

    Alva-Murillo, Nayeli; Ochoa-Zarzosa, Alejandra; López-Meza, Joel E.

    2017-01-01

    Bovine mammary epithelial cells (bMECs) contribute to mammary gland defense against invading pathogens, such as Staphylococcus aureus (intracellular facultative), which is recognized by TLR2. In a previous report, we showed that sodium octanoate [NaO, a medium chain fatty acid (C8)] induces (0.25 mM) or inhibits (1 mM) S. aureus internalization into bMECs and differentially regulates the innate immune response (IIR). However, the molecular mechanisms have not been described, which was the aim of this study. The results showed that α5β1 integrin membrane abundance (MA) was increased in 0.25 mM NaO-treated cells, but TLR2 or CD36 MA was not modified. When these receptors were blocked individually, 0.25 mM NaO-increased S. aureus internalization was notably reduced. Interestingly, in this condition, the IIR of the bMECs was impaired because MAPK (p38, JNK, and ERK1/2) phosphorylation and the activation of transcription factors related to these pathways were decreased. In addition, the 1 mM NaO treatment induced TLR2 MA, but neither the integrin nor CD36 MA was modified. The reduction in S. aureus internalization induced by 1 mM NaO was increased further when TLR2 was blocked. In addition, the phosphorylation levels of the MAPKs increased, and 13 transcriptional factors related to the IIR were slightly activated (CBF, CDP, c-Myb, AP-1, Ets-1/Pea-3, FAST-1, GAS/ISRE, AP-2, NFAT-1, OCT-1, RAR/DR-5, RXR/DR-1, and Stat-3). Moreover, the 1 mM NaO treatment up-regulated gene expression of IL-8 and RANTES and secretion of IL-1β. Notably, when 1 mM NaO-treated bMECs were challenged with S. aureus, the gene expression of IL-8 and IL-10 increased, while IL-1β secretion was reduced. In conclusion, our results showed that α5β1 integrin, TLR2 and CD36 are involved in 0.25 mM NaO-increased S. aureus internalization in bMECs. In addition, 1 mM NaO activates bMECs via the TLR2 signaling pathways (p38, JNK, and ERK1/2), which improves IIR before S. aureus invasion. Additionally

  17. HMGB1-RAGE regulates muscle satellite cell homeostasis through p38-MAPK- and myogenin-dependent repression of Pax7 transcription.

    PubMed

    Riuzzi, Francesca; Sorci, Guglielmo; Sagheddu, Roberta; Donato, Rosario

    2012-03-15

    Expression of the paired-box 7 (PAX7) transcription factor is regulated during both myoblast proliferation and differentiation: high levels of PAX7 compromise myogenic differentiation because of excess and prolonged proliferation, whereas low levels of PAX7 result in precocious differentiation. We showed that myogenin repressed Pax7 transcription in differentiating myoblasts by binding to specific recognition sites in the Pax7 promoter, and that high-mobility group box 1 (HMGB1)-receptor for advanced glycation end-products (RAGE) signaling was required for myogenin induction and myogenin-dependent repression of Pax7 transcription. In addition, PAX7 negatively and myogenin positively regulated RAGE expression. RAGE, a multiligand receptor of the immunoglobulin superfamily, was not expressed in adult skeletal muscles, and was transiently expressed in activated, proliferating and differentiating satellite cells (SCs) in injured muscles. Compared with wild-type muscles, Rage(-/-) muscles exhibited increased numbers of basal SCs that were further increased in injured Rage(-/-) muscles following elevated myoblast asymmetric division; complete regeneration of injured Rage(-/-) muscles was found to be delayed by ~1 week. Thus, RAGE signaling physiologically repressed Pax7 transcription in SCs by upregulating myogenin, thereby accelerating muscle regeneration and limiting SC self-renewal.

  18. Tricin, flavonoid from Njavara reduces inflammatory responses in hPBMCs by modulating the p38MAPK and PI3K/Akt pathways and prevents inflammation associated endothelial dysfunction in HUVECs.

    PubMed

    Shalini, V; Pushpan, Chithra K; G, Sindhu; A, Jayalekshmy; A, Helen

    2016-02-01

    Previous studies revealed the potent anti-inflammatory activity of tricin, the active component of Njavara rice bran. Here, we report the involvement of specific signaling pathways in the protective effect of tricin against LPS induced inflammation in hPBMCs and the role of tricin in modulating endothelial dysfunction in LPS induced HUVECs. Pretreatment with tricin (15μM) significantly inhibited the release of TNF-α and was comparable to the specific pathway blockers like ERK inhibitor (PD98059), JNK inhibitor (SP600125) and p38 inhibitor (SB203580), whereas an increased release of TNF-α was observed in PI3K/Akt inhibitor (LY294002) treated cells. Tricin alone and combination treatment of tricin and SB203580 showed more significant inhibition of activation of COX-2 and TNF-α than that of SB203580 alone treated group. Combination treatment of tricin and LY294002 showed increased activation of COX-2 and TNF-α, proved that PI3K activation is essential for the anti-inflammatory effect of tricin. Studies conducted on HUVECs revealed the protective effect of tricin against endothelial dysfunction associated with LPS induced inflammation by inhibiting the activation of proinflammatory mediators like TNF-α, IFN-γ, MCP 1 by modulating NF-κB and MAPK signaling pathways. ELISA and flow cytometric analysis again confirmed the protection of tricin against endothelial damage, especially from the decreased activation of cell adhesion molecules like ICAM-1, VCAM-1 and E-Selectin upon tricin treatment. This work establishes the mechanism behind the potent anti-inflammatory activity of the flavonoid tricin.

  19. Novel Noncatalytic Substrate-Selective p38α-Specific MAPK Inhibitors with Endothelial-Stabilizing and Anti-Inflammatory Activity.

    PubMed

    Shah, Nirav G; Tulapurkar, Mohan E; Ramarathnam, Aparna; Brophy, Amanda; Martinez, Ramon; Hom, Kellie; Hodges, Theresa; Samadani, Ramin; Singh, Ishwar S; MacKerell, Alexander D; Shapiro, Paul; Hasday, Jeffrey D

    2017-04-15

    The p38 MAPK family is composed of four kinases of which p38α/MAPK14 is the major proinflammatory member. These kinases contribute to many inflammatory diseases, but the currently available p38 catalytic inhibitors (e.g., SB203580) are poorly effective and cause toxicity. We reasoned that the failure of catalytic p38 inhibitors may derive from their activity against noninflammatory p38 isoforms (e.g., p38β/MAPK11) and loss of all p38α-dependent responses, including anti-inflammatory, counterregulatory responses via mitogen- and stress-activated kinase (MSK) 1/2 and Smad3. We used computer-aided drug design to target small molecules to a pocket near the p38α glutamate-aspartate (ED) substrate-docking site rather than the catalytic site, the sequence of which had only modest homology among p38 isoforms. We identified a lead compound, UM101, that was at least as effective as SB203580 in stabilizing endothelial barrier function, reducing inflammation, and mitigating LPS-induced mouse lung injury. Differential scanning fluorimetry and saturation transfer difference-nuclear magnetic resonance demonstrated specific binding of UM101 to the computer-aided drug design-targeted pockets in p38α but not p38β. RNA sequencing analysis of TNF-α-stimulated gene expression revealed that UM101 inhibited only 28 of 61 SB203580-inhibited genes and 7 of 15 SB203580-inhibited transcription factors, but spared the anti-inflammatory MSK1/2 pathway. We provide proof of principle that small molecules that target the ED substrate-docking site may exert anti-inflammatory effects similar to the catalytic p38 inhibitors, but their isoform specificity and substrate selectivity may confer inherent advantages over catalytic inhibitors for treating inflammatory diseases.

  20. Deoxysappanone B, a homoisoflavone from the Chinese medicinal plant Caesalpinia sappan L., protects neurons from microglia-mediated inflammatory injuries via inhibition of IκB kinase (IKK)-NF-κB and p38/ERK MAPK pathways.

    PubMed

    Zeng, Ke-Wu; Yu, Qian; Song, Fang-Jiao; Liao, Li-Xi; Zhao, Ming-Bo; Dong, Xin; Jiang, Yong; Tu, Peng-Fei

    2015-02-05

    Caesalpinia sappan L. (Lignum Sappan) is a Chinese medicinal plant for treating ischemic cerebral apoplexy. Deoxysappanone B (DSB), a homoisoflavone compound isolated from C. sappan L. (Lignum Sappan), was studied for anti-neuroinflammatory and neuroprotective properties using lipopolysaccharide (LPS)-induced BV-2 microglia neuroinflammation model and LPS-induced microglia-neuron co-culture system. Our findings showed that DSB effectively inhibited BV-2 microglia-mediated neuroinflammatory mediators׳ release including NO, PGE₂, TNF-α, IL-6 and reactive oxygen species. Moreover, DSB markedly protected neurons against inflammatory microglia-mediated neurotoxicity in a microglia-neuron co-culture system. Mechanism study revealed that DSB blocked two major neuroinflammation-related signaling pathways including IKK-IκB-nuclear factor kappaB (NF-κB) and p38/ERK mitogen-activated protein kinase (MAPK) cascades, further leading to the inhibition of neuroinflammatory mediators׳ production. The present study provides evidence that the anti-neuroinflammatory and neuroprotective effect of DSB are due to the suppression of neuroinflammatory mediators׳ production as well as inflammation-induced neurotoxicity through regulation of multi-targets. Therefore, DSB may serve as a neuroprotective agent for the treatment of neuroinflammatory disorders and inflammation-related neuronal injury.

  1. Combined treatment with vitamin C and methotrexate inhibits triple-negative breast cancer cell growth by increasing H2O2 accumulation and activating caspase-3 and p38 pathways.

    PubMed

    Wu, Ching-Wen; Liu, Hsiao-Chun; Yu, Yung-Luen; Hung, Yu-Ting; Wei, Chyou-Wei; Yiang, Giou-Teng

    2017-04-01

    Methotrexate (MTX) is widely used as both an anticancer and anti-rheumatoid arthritis drug. Although MTX has been used to inhibit the growth of many cancer cells, it cannot effectively inhibit growth of triple-negative breast cancer cells (TNBC cells). Vitamin C is an antioxidant that can prevent oxidative stress. In addition, vitamin C has been applied as adjunct treatment for growth inhibition of cancer cells. Recent studies indicated that combined treatment with vitamin C and MTX may inhibit MCF-7 and MDA-MB-231 breast cancer cell growth through G2/M elongation. However, the mechanisms remain unknown. The aim of the present study was to determine whether combined treatment with low-dose vitamin C and MTX inhibits TNBC cell growth and to investigate the mechanisms of vitamin C/MTX-induced cytotoxicity. Neither low-dose vitamin C alone nor MTX alone inhibited TNBC cell growth. However, combined low-dose vitamin C and MTX had synergistic anti-proliferative/cytotoxic effects on TNBC cells. In addition, co-treatment increased H2O2 levels and activated both caspase-3 and p38 cell death pathways.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-04-06

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

  4. Sann-Joong-Kuey-Jian-Tang induces autophagy in HepG2 cells via regulation of the phosphoinositide-3 kinase/Akt/mammalian target of rapamycin and p38 mitogen-activated protein kinase pathways.

    PubMed

    Chuang, Wan-Ling; Su, Chin-Cheng; Lin, Ping-Yi; Lin, Chi-Chen; Chen, Yao-Li

    2015-08-01

    Sann-Joong-Kuey-Jian-Tang (SJKJT), a traditional Chinese medicine, was previously reported to induce autophagy and inhibit the proliferation of the human HepG2 hepatocellular carcinoma cell line via an extrinsic pathway. In the present study, the effects of SJKJT-induced autophagy and the cytotoxic mechanisms mediating these effects were investigated in HepG2 cells. The cytotoxicity of SJKJT in the HepG2 cells was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The results demonstrated that the half-maximal inhibitory concentration of SJKJT was 2.91 mg/ml at 24 h, 1.64 mg/ml at 48 h and 1.26 mg/ml at 72 h. The results of confocal fluorescence microscopy indicated that SJKJT resulted in the accumulation of green fluorescent protein-LC3 and vacuolation of the cytoplasm. Flow cytometric analysis revealed the accumulation of acidic vesicular organelles. Furthermore, western blot analysis, used to determine the expression levels of autophagy-associated proteins, demonstrated that the HepG2 cells treated with SJKJT exhibited LC3B-I/LC3B-II conversion, increased expression levels of Beclin, Atg-3 and Atg-5 and reduced expression levels of p62 and decreased signaling of the phosphoinositide-3 kinase/Akt/mammalian target of rapamycin and the p38 mitogen-activated protein kinase pathways. Taken together, these findings may assist in the development of novel chemotherapeutic agents for the treatment of malignant types of liver cancer.

  5. Sann-Joong-Kuey-Jian-Tang induces autophagy in HepG2 cells via regulation of the phosphoinositide-3 kinase/Akt/mammalian target of rapamycin and p38 mitogen-activated protein kinase pathways

    PubMed Central

    CHUANG, WAN-LING; SU, CHIN-CHENG; LIN, PING-YI; LIN, CHI-CHEN; CHEN, YAO-LI

    2015-01-01

    Sann-Joong-Kuey-Jian-Tang (SJKJT), a traditional Chinese medicine, was previously reported to induce autophagy and inhibit the proliferation of the human HepG2 hepatocellular carcinoma cell line via an extrinsic pathway. In the present study, the effects of SJKJT-induced autophagy and the cytotoxic mechanisms mediating these effects were investigated in HepG2 cells. The cytotoxicity of SJKJT in the HepG2 cells was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The results demonstrated that the half-maximal inhibitory concentration of SJKJT was 2.91 mg/ml at 24 h, 1.64 mg/ml at 48 h and 1.26 mg/ml at 72 h. The results of confocal fluorescence microscopy indicated that SJKJT resulted in the accumulation of green fluorescent protein-LC3 and vacuolation of the cytoplasm. Flow cytometric analysis revealed the accumulation of acidic vesicular organelles. Furthermore, western blot analysis, used to determine the expression levels of autophagy-associated proteins, demonstrated that the HepG2 cells treated with SJKJT exhibited LC3B-I/LC3B-II conversion, increased expression levels of Beclin, Atg-3 and Atg-5 and reduced expression levels of p62 and decreased signaling of the phosphoinositide-3 kinase/Akt/mammalian target of rapamycin and the p38 mitogen-activated protein kinase pathways. Taken together, these findings may assist in the development of novel chemotherapeutic agents for the treatment of malignant types of liver cancer. PMID:25847489

  6. FR-167653, a selective p38 MAPK inhibitor, exerts salutary effect on liver cirrhosis through downregulation of Runx2.

    PubMed

    Hattori, Shinji; Dhar, Dipok K; Hara, Nobumasa; Tonomoto, Yasuhito; Onoda, Toshinao; Ono, Takashi; Yamanoi, Akira; Tachibana, Mitsuo; Tsuchiya, Mikako; Nagasue, Naofumi

    2007-06-01

    Liver cirrhosis remains a difficult-to-treat disease with a substantial morbidity and mortality rate. There is an emerging body of data purporting a pivotal role of the activated p38 mitogen-activated protein kinase (MAPK) in the process of cirrhosis. Several anticirrhotic agents have been developed over the past few years, and most of them exert their effects by indirectly inhibiting the p38 pathway. Effect of a selective p38 inhibitor is yet to be reported. In this study, we evaluated the salutary effect of FR-167653 (FR), a selective p38 inhibitor, in a carbon tetrachloride (CCl(4))-induced rat cirrhotic model. Twenty rats were assigned into four groups: Sham, olive oil only; Control, CCl(4) in olive oil; FR50, FR 50 mg/kg/day and CCl(4); and FR100, FR 100 mg/kg/day and CCl(4). FR dose-dependently inhibited activation of p38 and had an ameliorating effect on cirrhosis formation. Significant dose-dependent reduction in alpha-smooth muscle actin immunostaining and hydroxyproline content of the liver was noticed in the FR-treated rats. Also densitometric analysis showed a significant reduction in azan-stained area in the FR-treated rats. These fibrotic changes were observed in the myofibroblasts including the hepatic stellate cells and portal fibroblasts. mRNA expression of runt-related protein 2 (Runx2), a profibrogenic transcription factor, was significantly low in FR-treated livers, indicating that Runx2 might be a key downstream regulator of the p38 pathway. A similar reduction in expression of Smad4 and tissue inhibitor of metalloproteinase-1 was noticed in the FR-treated rats. In conclusion, FR treatment exerted a significant beneficial effect in a CCl(4)-induced rat cirrhotic model. The ameliorating effect of FR could be partially attributable to an inhibition of the Smad4/p38/Runx2 axis in the cirrhotic liver.

  7. Selective p38α MAP kinase/MAPK14 inhibition in enzymatically modified LDL-stimulated human monocytes: implications for atherosclerosis.

    PubMed

    Cheng, Fei; Twardowski, Laura; Fehr, Sarah; Aner, Christoph; Schaeffeler, Elke; Joos, Thomas; Knorpp, Thomas; Dorweiler, Bernhard; Laufer, Stefan; Schwab, Matthias; Torzewski, Michael

    2017-02-01

    The first ATP-competitive p38α MAPK/MAPK14 inhibitor with excellent in vivo efficacy and selectivity, skepinone-L, is now available. We investigated the impact of selective p38α MAPK/MAPK14 inhibition on enzymatically modified LDL (eLDL) stimulated human monocytes with its implications for atherosclerosis. Among the different p38 MAPK isoforms, p38α/MAPK14 was the predominantly expressed and activated isoform in isolated human peripheral blood monocytes. Moreover, eLDL colocalized with macrophages positive for p38α MAPK/MAPK14 in human carotid endarterectomy specimens. Using the human leukemia cell line THP-1 and/or primary monocyte-derived macrophages, skepinone-L inhibited eLDL-induced activation of the p38 MAPK pathway, inhibited eLDL induced expression of both cluster of differentiation 36 (CD36) and ATP-binding cassette, subfamily A, member 1 (ABCA1), without a net effect on foam cell formation, had a cell- and time-dependent effect on eLDL-triggered apoptosis, and inhibited eLDL-stimulated secretion of IL-8 and MIP-1β/CCL4 (macrophage inflammatory protein-1β/chemokine, CC motif, ligand 4). Inhibition of a key signaling molecule of the p38 MAPK pathway, p38α MAPK/MAPK14, by selective inhibitors like skepinone-L, conclusively facilitates elucidation of the impact of the complex network of p38 MAPK signaling on atherogenesis and might provide a promising therapeutic tool to prevent inflammatory cascades in atherosclerosis.-Cheng, F., Twardowski, L., Fehr, S., Aner, C., Schaeffeler, E., Joos, T., Knorpp, T., Dorweiler, B., Laufer, S., Schwab, M., Torzewski, M. Selective p38α MAP kinase/MAPK14 inhibition in enzymatically modified LDL-stimulated human monocytes: implications for atherosclerosis.

  8. RhoA and p38 MAPK mediate apoptosis induced by cellular cholesterol depletion.

    PubMed

    Calleros, Laura; Lasa, Marina; Rodríguez-Alvarez, Francisco J; Toro, María J; Chiloeches, Antonio

    2006-07-01

    Cholesterol is essential for cell viability, and homeostasis of cellular cholesterol is crucial to various cell functions. Here we examined the effect of cholesterol depletion on apoptosis and the mechanisms underlying this effect in NIH3T3 cells. We show that chronic cholesterol depletion achieved with lipoprotein-deficient serum (LPDS) and 25-hydroxycholesterol (25-HC) treatment resulted in a significant increase in cellular apoptosis and caspase-3 activation. This effect is not due to a deficiency of nonsterol isoprenoids, intermediate metabolites of the cholesterol biosynthetic pathway, but rather to low cholesterol levels, since addition of cholesterol together with LPDS and 25-HC nearly abolished apoptosis, whereas addition of farnesyl pyrophosphate or geranylgeranyl-pyrophosphate did not reverse the cell viability loss induced by LPDS plus 25-HC treatment. These effects were accompanied by an increase in ERK, JNK and p38 MAPK activity. However, only the inhibition of p38 MAPK with the specific inhibitor SB203580 or the overexpression of a kinase defective MKK6 resulted in a significant decrease in apoptosis and caspase-3 cleavage induced by cholesterol depletion. Furthermore, LPDS plus 25-HC increased RhoA activity, and this effect was reversed by addition of exogenous cholesterol. Finally, overexpression of the dominant negative N19RhoA inhibited p38 MAPK phosphorylation and apoptosis induced by low cholesterol levels. Together, our results demonstrate that cholesterol depletion induces apoptosis through a RhoA- and p38 MAPK-dependent mechanism.

  9. MAP kinase p38α regulates type III interferon (IFN-λ1) gene expression in human monocyte-derived dendritic cells in response to RNA stimulation.

    PubMed

    Jiang, Miao; Österlund, Pamela; Fagerlund, Riku; Rios, Diana N; Hoffmann, Alexander; Poranen, Minna M; Bamford, Dennis H; Julkunen, Ilkka

    2015-02-01

    Recognition of viral nucleic acids leads to type I and type III IFN gene expression and activation of host antiviral responses. At present, type III IFN genes are the least well-characterized IFN types. Here, we demonstrate that the p38 MAPK signaling pathway is involved in regulating IFN-λ1 gene expression in response to various types of RNA molecules in human moDCs. Inhibition of p38 MAPK strongly reduced IFN gene expression, and overexpression of p38α MAPK enhanced IFN-λ1 gene expression in RNA-stimulated moDCs. The regulation of IFN gene expression by p38 MAPK signaling was independent of protein synthesis and thus, a direct result of RNA stimulation. Moreover, the RIG-I/MDA5-MAVS-IRF3 pathway was required for p38α MAPK to up-regulate IFN-λ1 promoter activation, whereas the MyD88-IRF7 pathway was not needed, and the regulation was not involved directly in IRF7-dependent IFN-α1 gene expression. The stimulatory effect of p38α MAPK on IFN-λ1 mRNA expression in human moDCs did not take place directly via the activating TBK1/IKKε complex, but rather, it occurred through some other parallel pathways. Furthermore, mutations in ISRE and NF-κB binding sites in the promoter region of the IFN-λ1 gene led to a significant reduction in p38α MAPK-mediated IFN responses after RNA stimulation. Altogether, our data suggest that the p38α MAPK pathway is linked with RLR signaling pathways and regulates the expression of early IFN genes after RNA stimulation cooperatively with IRF3 and NF-κB to induce antiviral responses further.

  10. Inhibition of p38 MAPK Phosphorylation Is Critical for Bestatin to Enhance ATRA-Induced Cell Differentiation in Acute Promyelocytic Leukemia NB4 Cells.

    PubMed

    Qian, Xijun; He, Jingsong; Zhao, Yi; Lin, Maofang

    2016-01-01

    Bestatin has been known as an immunomodulating agent in anti-leukemia treatment. The mechanism by which Bestatin enhances all-trans retinoic acid (ATRA)-induced cell differentiation of acute promyelocytic leukemia (APL) cells is generally attributed to inhibition of cell surface CD13/aminopeptidase N activity. Bestatin also exerts its biological activities besides its ability to inhibit aminopeptidase N enzymatic activity. This article provides data to support an alternative mechanism regarding an important role of inhibition of p38 mitogen-activated protein kinase (MAPK) signal pathway in Bestatin's anti-leukemia effect. Bestatin enhanced ATRA-induced differentiation and inhibited ATRA-driven phosphorylation of p38 MAPK in ATRA-sensitive APL NB4 cells. In contrast, Bestatin could not reverse the differentiation block in ATRA-resistant APL MR2 cells, in which ATRA was unable to induce phosphorylation of p38 MAPK. Moreover, CD13 ligation with anti-CD13 antibody WM-15 resulted in phosphorylation of p38 MAPK, reduced the inhibition of Bestatin on the phosphorylation of p38 MAPK, and completely abolished the enhancement of Bestatin on ATRA-inducing differentiation in NB4 cells. This study shows that inhibition of p38 MAPK phosphorylation is critical for Bestatin to enhance ATRA-induced cell differentiation in ATRA-sensitive APL NB4 cells. Results suggested that pharmacological inhibition of the p38 MAPK pathway might enhance ATRA-dependent differentiation.

  11. Schwann Cell Migration Induced by Earthworm Extract via Activation of PAs and MMP2/9 Mediated through ERK1/2 and p38

    PubMed Central

    Chang, Yung-Ming; Shih, Ying-Ting; Chen, Yueh-Sheng; Liu, Chien-Liang; Fang, Wen-Kuei; Tsai, Chang-Hai; Tsai, Fuu-Jen; Kuo, Wei-Wen; Lai, Tung-Yuan; Huang, Chih-Yang

    2011-01-01

    The earthworm, which has stasis removal and wound-healing functions, is a widely used Chinese herbal medicine in China. Schwann cell migration is critical for the regeneration of injured nerves. Schwann cells provide an essentially supportive activity for neuron regeneration. However, the molecular migration mechanisms induced by earthworms in Schwann cells remain unclear. Here, we investigate the roles of MAPK (ERK1/2, JNK and p38) pathways for earthworm-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in Schwann cells. Moreover, earthworm induced phosphorylation of ERK1/2 and p38, but not JNK, activate the downstream signaling expression of PAs and MMPs in a time-dependent manner. Earthworm-stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with U0126 and SB203580, resulting in migration and uPA-related signal pathway inhibition. The results were confirmed using small interfering ERK1/2 and p38 RNA. These results demonstrated that earthworms can stimulate Schwann cell migration and up-regulate PAs and MMP2/9 expression mediated through the MAPK pathways, ERK1/2 and p38. Taken together, our data suggests the MAPKs (ERK1/2, p38)-, PAs (uPA, tPA)-, MMP (MMP2, MMP9) signaling pathway of Schwann cells regulated by earthworms might play a major role in Schwann cell migration and nerve regeneration. PMID:19808845

  12. EPO gene expression promotes proliferation, migration and invasion via the p38MAPK/AP-1/MMP-9 pathway by p21WAF1 expression in vascular smooth muscle cells.

    PubMed

    Park, Sung Lyea; Won, Se Yeon; Song, Jun-Hui; Kambe, Taiho; Nagao, Masaya; Kim, Wun-Jae; Moon, Sung-Kwon

    2015-03-01

    The use of recombinant human erythropoietin (rHuEpo) can lead to hypertrophy and hyperplasia, and has induced the proliferation of vascular smooth muscle cells (VSMCs). The effect of the EPO gene in the migration and invasion of VSMCs remains unclear. In this study, overexpression of the EPO gene increased the DNA synthesis and phosphorylation of ERK1/2 and p38MAPK in VSMCs. In addition, EPO gene expression induced the migration and invasion of VSMCs via the expression of MMP-9 by the activation of NF-κB and AP-1 binding. A blockade of p38MAPK by specific p38MAPK inhibitor SB203580 led to a suppression of the increased DNA synthesis, migration, and invasion of VSMCs that was induced by the EPO gene. SB203580 treatment blocked the increased expression of MMP-9 through the binding activity of AP-1. Transfection of the EPO gene with VSMCs was associated with the up-regulation of cyclin D1/CDK4, cyclin E/CDK2, and p21WAF1, and with the down-regulation of p27KIP1. The specific suppression of p21WAF1 expression by siRNA rescued the enhancement of DNA synthesis via the phosphorylation of p38MAPK and the increase in migration and invasion through AP-1-mediated MMP-9 expression in EPO gene transfectants. These novel findings demonstrate that p21WAF1 regulates the proliferation, migration and invasion of VSMC induced by EPO gene.

  13. Pretreatment with pPolyHb attenuates H2O2-induced endothelial cell injury through inhibition of JNK/p38 MAPK pathway by upregulation of heme oxygenase-1.

    PubMed

    Xue, Haiyan; Yan, Kunping; Zhao, Xiufang; Zhu, Wenjin; Liu, Lijun; Xie, Zhilan; Zhu, Hongli; Chen, Chao

    2015-06-01

    Polymerized porcine hemoglobin (pPolyHb) exhibits a protective effect on ischemia/reperfusion of organ grafts. A series of experiments were performed to explore the underlying cytoprotective mechanisms of pPolyHb pretreatment on H2O2-induced cell death and apoptosis. The results showed that the pretreatment augmented heme oxygenase-1 (HO-1) expression, and at the same time, decreased the phosphorylation of JNK/p38 mitogen-activated protein kinase (MAPK) and intracellular ROS generation in H2O2-treated HUVECs. Moreover, the inhibition of HO-1 expression by tin porphyrin (SnPP) abolished the protective effects of pPolyHb, which suggested that the cytoprotective effect of pPolyHb involves upregulating HO-1 and subsequently decreasing the phosphorylation of the JNK and p38 MAPK and ROS generation.

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

    PubMed

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

    2014-12-01

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

  15. A posttranslational modification cascade involving p38, Tip60, and PRAK mediates oncogene-induced senescence.

    PubMed

    Zheng, Hui; Seit-Nebi, Alim; Han, Xuemei; Aslanian, Aaron; Tat, John; Liao, Rong; Yates, John R; Sun, Peiqing

    2013-06-06

    Oncogene-induced senescence is an important tumor-suppressing defense mechanism. However, relatively little is known about the signaling pathway mediating the senescence response. Here, we demonstrate that a multifunctional acetyltransferase, Tip60, plays an essential role in oncogenic ras-induced senescence. Further investigation reveals a cascade of posttranslational modifications involving p38, Tip60, and PRAK, three proteins that are essential for ras-induced senescence. Upon activation by ras, p38 induces the acetyltransferase activity of Tip60 through phosphorylation of Thr158; activated Tip60 in turn directly interacts with and induces the protein kinase activity of PRAK through acetylation of K364 in a manner that depends on phosphorylation of both Tip60 and PRAK by p38. These posttranslational modifications are critical for the prosenescent function of Tip60 and PRAK, respectively. These results have defined a signaling pathway that mediates oncogene-induced senescence, and identified posttranslational modifications that regulate the enzymatic activity and biological functions of Tip60 and PRAK.

  16. Synthetic phosphorylation of p38α recapitulates protein kinase activity.

    PubMed

    Chooi, K Phin; Galan, Sébastien R G; Raj, Ritu; McCullagh, James; Mohammed, Shabaz; Jones, Lyn H; Davis, Benjamin G

    2014-02-05

    Through a "tag-and-modify" protein chemical modification strategy, we site-selectively phosphorylated the activation loop of protein kinase p38α. Phosphorylation at natural (180) and unnatural (172) sites created two pure phospho-forms. p38α bearing only a single phosphocysteine (pCys) as a mimic of pThr at 180 was sufficient to switch the kinase to an active state, capable of processing natural protein substrate ATF2; 172 site phosphorylation did not. In this way, we chemically recapitulated triggering of a relevant segment of the MAPK-signaling pathway in vitro. This allowed detailed kinetic analysis of global and stoichiometric phosphorylation events catalyzed by p38α and revealed that site 180 is a sufficient activator alone and engenders dominant mono-phosphorylation activity. Moreover, a survey of kinase inhibition using inhibitors with different (Type I/II) modes (including therapeutically relevant) revealed unambiguously that Type II inhibitors inhibit phosphorylated p38α and allowed discovery of a predictive kinetic analysis based on cooperativity to distinguish Type I vs II.

  17. Novel regulation of p38gamma by dopamine D2 receptors during hypoxia.

    PubMed

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

    2000-07-01

    The p38 signalling pathway is part of the MAPK superfamily and is activated by various stressors. Our previous results have shown that two p38 isoforms, p38alpha and p38gamma, are activated by hypoxia in the neural-like PC12 cell line. PC12 cells also synthesize and secrete catecholamines, including dopamine, in response to hypoxia. We have now used this system to study the interaction between D2-dopamine receptor signalling and the p38 stress-activated protein kinases. Our results show that two D2 receptor antagonists, butaclamol and sulpiride, enhance hypoxia-induced phosphorylation of p38gamma, but not p38. This effect persists in protein kinase A (PKA)-deficient PC12 cells, demonstrating that p38gamma modulation by the D2 receptor is independent of the cAMP/PKA signalling system. We further show that removal of extracellular calcium blocks the hypoxia-induced increase in p38gamma activity. These results are the first to demonstrate that p38gamma can be regulated by the D2 receptor and calcium following hypoxic exposure.

  18. Mitogen-activated protein kinases p38 and JNK mediate Actinobacillus pleuropneumoniae exotoxin ApxI-induced apoptosis in porcine alveolar macrophages.

    PubMed

    Wu, Chi-Ming; Chen, Zeng-Weng; Chen, Ter-Hsin; Liao, Jiunn-Wang; Lin, Cheng-Chung; Chien, Maw-Sheng; Lee, Wei-Cheng; Hsuan, Shih-Ling

    2011-08-05

    Actinobacillus pleuropneumoniae exotoxins (Apx) are major virulence factors that play important roles in the pathogenesis of pleuropneumonia in swine. A previous study has demonstrated that native ApxI at low concentrations induces apoptosis in primary porcine alveolar macrophages (PAMs) via a caspase-3-dependent pathway. However, the molecular mechanisms underlying ApxI-induced apoptosis remain largely unknown. In this study, it was shown that ApxI treatment in PAMs rapidly induced phosphorylation of both p38 and JNK, members of the mitogen-activated protein kinase family. Application of a selective p38 or JNK inhibitor significantly reduced ApxI-induced apoptosis, indicating the involvement of p38 and JNK pathways in this event. Furthermore, activation of both caspase-8 and -9 were observed in ApxI-stimulated PAMs. Inhibition of caspase-8 and caspase-9 activity significantly protected PAMs from ApxI-induced apoptosis. In addition, Bid activation was also noted in ApxI-treated PAMs, and inhibition of caspase-8 suppressed the activation of Bid and caspase-9, suggesting that ApxI was able to activate the caspases-8-Bid-caspase-9 pathway. Notably, inhibition of p38 or JNK pathway greatly attenuated the activation of caspases-3, -8, and -9. This study is the first to demonstrate that ApxI-induced apoptosis of PAMs involves the activation of p38 and JNK, and engages the extrinsic and intrinsic apoptotic pathways.

  19. Peptide IDR-1002 Inhibits NF-κB Nuclear Translocation by Inhibition of IκBα Degradation and Activates p38/ERK1/2–MSK1-Dependent CREB Phosphorylation in Macrophages Stimulated with Lipopolysaccharide

    PubMed Central

    Huante-Mendoza, Alejandro; Silva-García, Octavio; Oviedo-Boyso, Javier; Hancock, Robert E. W.; Baizabal-Aguirre, Víctor M.

    2016-01-01

    The inflammatory response is a critical molecular defense mechanism of the innate immune system that mediates the elimination of disease-causing bacteria. Repair of the damaged tissue, and the reestablishment of homeostasis, must be accomplished after elimination of the pathogen. The innate defense regulators (IDRs) are short cationic peptides that mimic natural host defense peptides and are effective in eliminating pathogens by enhancing the activity of the immune system while controlling the inflammatory response. Although the role of different IDRs as modulators of inflammation has been reported, there have been only limited studies of the signaling molecules regulated by this type of peptide. The present study investigated the effect of IDR-1002 on nuclear factor κB (NF-κB) and cAMP-response element-binding protein (CREB) transcription factors that are responsible for triggering and controlling inflammation, respectively, in macrophages. We found that TNF-α and COX-2 expression, IκBα phosphorylation, and NF-κB nuclear translocation were strongly inhibited in macrophages pre-incubated with IDR-1002 and then stimulated with lipopolysaccharide (LPS). IDR-1002 also increased CREB phosphorylation at Ser133 via activation of the p38/ERK1/2–MSK1 signaling pathways without detectable expression of the cytokines IL-4, IL-10, and IL-13 involved is suppressing inflammation or alternative activation. Transcriptional activation of NF-κB and CREB is known to require interaction with the transcriptional coactivator CREB-binding protein (CBP). To test for CBP–NF-κB and CBP–CREB complex formation, we performed co-immunoprecipitation assays. These assays showed that IDR-1002 inhibited the interaction between CBP and NF-κB in macrophages stimulated with LPS, which might explain the inhibition of TNF-α and COX-2 expression. Furthermore, the complex between CBP and CREB in macrophages stimulated with IDR-1002 was also inhibited, which might explain why IDR-1002 did

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

    PubMed Central

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

    2016-01-01

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

  1. Curcumin downregulates p38 MAPK-dependent X-ray repair cross-complement group 1 (XRCC1) expression to enhance cisplatin-induced cytotoxicity in human lung cancer cells.

    PubMed

    Tung, Chun-Liang; Jian, Yi-Jun; Chen, Jyh-Cheng; Wang, Tai-Jing; Chen, Wen-Ching; Zheng, Hao-Yu; Chang, Po-Yuan; Liao, Kai-Sheng; Lin, Yun-Wei

    2016-06-01

    Cisplatin is a well-studied and widely used chemotherapeutic agent and is effective in the treatment of the advanced human non-small cell lung cancer (NSCLC). Curcumin is a yellow pigment derived from the rhizome of Curcuma longa and has been proved to have antioxidant and antitumor properties. XRCC1 is an important scaffold protein involved in base excision repair and plays an important role in the development of lung cancer. In this study, we characterize the role of curcumin in the cytotoxicity, p38 MAPK activation, and XRCC1 expression affected by cisplatin in NSCLC cells. We show that curcumin enhanced the cytotoxicity induced by cisplatin in two NSCLC cells, A549 and H1703. Treatment with cisplatin alone increased XRCC1 mRNA and protein expression through p38 MAPK activation. Moreover, SB2023580 (p38 inhibitor) decreased the XRCC1 mRNA and protein stability upon cisplatin treatment. Knockdown of XRCC1 in NSCLC cells by transfection of XRCC1 siRNA or inactivation of p38 MAPK resulted in enhancing the cytotoxicity and cell growth inhibition induced by cisplatin. Curcumin inhibited the expression of XRCC1 in cisplatin-exposed NSCLC cells. Furthermore, transfection with constitutive active MKK6 or HA-p38 MAPK vectors rescued the XRCC1 protein level and also the cell survival suppressed by cisplatin and curcumin combination in A549 and H1703 cells. These findings suggested that the downregulation of XRCC1 expression by curcumin can enhance the chemosensitivity of cisplatin in NSCLC cells.

  2. p38 MAPK Signaling in Postnatal Tendon Growth and Remodeling

    PubMed Central

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

    2015-01-01

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

  3. UVB-mediated activation of p38 mitogen-activated protein kinase enhances resistance of normal human keratinocytes to apoptosis by stabilizing cytoplasmic p53.

    PubMed

    Chouinard, Nadine; Valerie, Kristoffer; Rouabhia, Mahmoud; Huot, Jacques

    2002-07-01

    Human keratinocytes respond to UV rays by developing a fast adaptive response that contributes to maintaining their functions and survival. We investigated the role of the mitogen-activated protein kinase pathways in transducing the UV signals in normal human keratinocytes. We found that UVA, UVB or UVC induced a marked and persistent activation of p38, whereas c-Jun N-terminal kinase or extracellular signal-regulated kinase were less or not activated respectively. Inhibition of p38 activity by expression of a dominant-negative mutant of p38 or with SB203580 impaired cell viability and led to an increase in UVB-induced apoptosis. This sensitization to apoptosis was independent of caspase activities. Inhibition of p38 did not sensitize transformed HaCaT keratinocytes to UVB-induced apoptosis. In normal keratinocytes, expression of a dominant-negative mutant of p53 increased UVB-induced cell death, pointing to a role for p53. In these cells, UVB triggered a p38-dependent phosphorylation of p53 on Ser-15. This phosphorylation was associated with an SB203580-sensitive accumulation of p53, even in the presence of a serine phosphatase inhibitor. Accumulated p53 was localized mainly in the cytoplasm, independently of CRM1 nuclear export. In HaCaT cells, p53 was localized exclusively in the nucleus and its distribution and level were not affected by UVB or p38 inhibition. However, UVB induced an SB203580-insensitive phosphorylation on Ser-15 of mutated p53. Overall, our results suggest that, in normal human keratinocytes, protection against UVB depends on p38-mediated phosphorylation and stabilization of p53 and is tightly associated with the cytoplasmic sequestration of wild-type p53. We conclude that the p38/p53 pathway plays a key role in the adaptive response of normal human keratinocytes against UV stress.

  4. Annexin II-dependent actin remodelling evoked by hydrogen peroxide requires the metalloproteinase/sphingolipid pathway.

    PubMed

    Cinq-Frais, Christel; Coatrieux, Christelle; Savary, Aude; D'Angelo, Romina; Bernis, Corinne; Salvayre, Robert; Nègre-Salvayre, Anne; Augé, Nathalie

    2015-01-01

    Actin remodeling is a dynamic process associated with cell shape modification occurring during cell cycle and proliferation. Oxidative stress plays a role in actin reorganization via various systems including p38MAPK. Beside, the mitogenic response evoked by hydrogen peroxide (H2O2) in fibroblasts and smooth muscle cells (SMC) involves the metalloproteinase (MMPs)/sphingomyelinase 2 (nSMase2) signaling pathway. The aim of this work was to investigate whether this system plays a role in actin remodeling induced by H2O2. Low H2O2 dose (5µM) rapidly triggered a signaling cascade leading to nSMase2 activation, src and annexin 2 (AnxA2) phosphorylation, and actin remodeling, in fibroblasts and SMC. These events were blocked by pharmacological inhibitors of MMPs (Ro28-2653) and p38MAPK (SB203580), and were lacking in MMP2(-/-) and in nSMase2-mutant (fro) fibroblasts. Likewise, H2O2 was unable to induce actin remodeling in fro and MMP2(-/-) fibroblasts or in cells pretreated with p38MAPK, or MMP inhibitors. Finally we show that nSMase2 activation by H2O2, depends on MMP2 and p38MAPK, and is required for the src-dependent phosphorylation of AnxA2, and actin remodeling. Taken together, these findings indicate for the first time that AnxA2 phosphorylation and actin remodeling evoked by oxidative stress depend on the sphingolipid pathway, via MMP2 and p38MAPK.

  5. Annexin II-dependent actin remodelling evoked by hydrogen peroxide requires the metalloproteinase/sphingolipid pathway

    PubMed Central

    Cinq-Frais, Christel; Coatrieux, Christelle; Savary, Aude; D’Angelo, Romina; Bernis, Corinne; Salvayre, Robert; Nègre-Salvayre, Anne; Augé, Nathalie

    2014-01-01

    Actin remodeling is a dynamic process associated with cell shape modification occurring during cell cycle and proliferation. Oxidative stress plays a role in actin reorganization via various systems including p38MAPK. Beside, the mitogenic response evoked by hydrogen peroxide (H2O2) in fibroblasts and smooth muscle cells (SMC) involves the metalloproteinase (MMPs)/sphingomyelinase 2 (nSMase2) signaling pathway. The aim of this work was to investigate whether this system plays a role in actin remodeling induced by H2O2. Low H2O2 dose (5 µM) rapidly triggered a signaling cascade leading to nSMase2 activation, src and annexin 2 (AnxA2) phosphorylation, and actin remodeling, in fibroblasts and SMC. These events were blocked by pharmacological inhibitors of MMPs (Ro28-2653) and p38MAPK (SB203580), and were lacking in MMP2−/− and in nSMase2-mutant (fro) fibroblasts. Likewise, H2O2 was unable to induce actin remodeling in fro and MMP2−/− fibroblasts or in cells pretreated with p38MAPK, or MMP inhibitors. Finally we show that nSMase2 activation by H2O2, depends on MMP2 and p38MAPK, and is required for the src-dependent phosphorylation of AnxA2, and actin remodeling. Taken together, these findings indicate for the first time that AnxA2 phosphorylation and actin remodeling evoked by oxidative stress depend on the sphingolipid pathway, via MMP2 and p38MAPK. PMID:25574848

  6. l-Theanine, an amino acid in green tea, attenuates beta-amyloid-induced cognitive dysfunction and neurotoxicity: reduction in oxidative damage and inactivation of ERK/p38 kinase and NF-kappaB pathways.

    PubMed

    Kim, Tae Il; Lee, Yong Kyung; Park, Sang Gi; Choi, Im Seop; Ban, Jung Ok; Park, Hyoung Kook; Nam, Sang-Yoon; Yun, Young Won; Han, Sang Bae; Oh, Ki Wan; Hong, Jin Tae

    2009-12-01

    Amyloid beta (Abeta)-induced neurotoxicity is a major pathological mechanism of Alzheimer disease (AD). In this study, we investigated the inhibitory effect of l-theanine, a component of green tea (Camellia sinensis), on Abeta(1-42)-induced neuronal cell death and memory impairment. Oral treatment of l-theanine (2 and 4 mg/kg) for 5 weeks in the drinking water of mice, followed by injection of Abeta(1-42) (2 microg/mouse, icv), significantly attenuated Abeta(1-42)-induced memory impairment. Furthermore, l-theanine reduced Abeta(1-42) levels and the accompanying Abeta(1-42)-induced neuronal cell death in the cortex and hippocampus of the brain. Moreover, l-theanine inhibited Abeta(1-42)-induced extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase as well as the activity of nuclear factor kappaB (NF-kappaB). l-Theanine also significantly reduced oxidative protein and lipid damage and the elevation of glutathione levels in the brain. These data suggest that the positive effects of l-theanine on memory may be mediated by suppression of ERK/p38 and NF-kappaB as well as the reduction of macromolecular oxidative damage. Thus, l-theanine may be useful in the prevention and treatment of AD.

  7. Loss of Functionally Redundant p38 Isoforms in T Cells Enhances Regulatory T Cell Induction*

    PubMed Central

    Hayakawa, Morisada; Hayakawa, Hiroko; Petrova, Tsvetana; Ritprajak, Patcharee; Sutavani, Ruhcha V.; Jiménez-Andrade, Guillermina Yanek; Sano, Yasuyo; Choo, Min-Kyung; Seavitt, John; Venigalla, Ram K. C.; Otsu, Kinya; Georgopoulos, Katia; Arthur, J. Simon C.; Park, Jin Mo

    2017-01-01

    The evolutionarily conserved protein kinase p38 mediates innate resistance to environmental stress and microbial infection. Four p38 isoforms exist in mammals and may have been co-opted for new roles in adaptive immunity. Murine T cells deficient in p38α, the ubiquitously expressed p38 isoform, showed no readily apparent cell-autonomous defects while expressing elevated amounts of another isoform, p38β. Mice with T cells simultaneously lacking p38α and p38β displayed lymphoid atrophy and elevated Foxp3+ regulatory T cell frequencies. Double deficiency of p38α and p38β in naïve CD4+ T cells resulted in an attenuation of MAPK-activated protein kinase (MK)-dependent mTOR signaling after T cell receptor engagement, and enhanced their differentiation into regulatory T cells under appropriate inducing conditions. Pharmacological inhibition of the p38-MK-mTOR signaling module produced similar effects, revealing potential for therapeutic applications. PMID:28011639

  8. Lockheed P-38 Lightning in flight

    NASA Technical Reports Server (NTRS)

    1943-01-01

    The P-38 shown in this photo was one of the fighters built in the late 1930s and early 1940s that experienced compressibility effects. In steep dives, these aircraft could reach speeds above Mach 0.75 (called transonic). At transonic speeds, air in front of the wings became compressed and reached supersonic speeds as it flowed over the wings, forming a shock wave. This resulted in an increase in drag and a decrease in lift. Another result was the movement of the wing's center of lift to the rear, forcing the aircraft to rotate so that the nose moved downward and it went into a steep dive. Pilots found that that their aircraft would not pull out of this dive. When they attempted to pull out, they found the control stick, as one pilot put it, 'was cast in about two feet of concrete.' In some cases, the airplanes crashed or broke up in the denser air as they approached the ground. In other cases, the pilots were able to pull out of the dive. These accidents and near misses reinforced the popular belief in a 'sound barrier.' The need for data at speeds near that of sound and the inability of wind tunnels at the time to provide it would lead to the construction and flight of the X-1 and D-558 research aircraft. The Lockheed P-38 Lightning was one of the best-known Army Air Forces fighters that flew in World War II