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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. Metabolic respiration induces AMPK- and Ire1p-dependent activation of the p38-Type HOG MAPK pathway.

    PubMed

    Adhikari, Hema; Cullen, Paul J

    2014-10-01

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

  3. 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

  4. Disulfiram eradicates tumor-initiating hepatocellular carcinoma cells in ROS-p38 MAPK pathway-dependent and -independent manners.

    PubMed

    Chiba, Tetsuhiro; Suzuki, Eiichiro; Yuki, Kaori; Zen, Yoh; Oshima, Motohiko; Miyagi, Satoru; Saraya, Atsunori; Koide, Shuhei; Motoyama, Tenyu; Ogasawara, Sadahisa; Ooka, Yoshihiko; Tawada, Akinobu; Nakatsura, Tetsuya; Hayashi, Takehiro; Yamashita, Taro; Kaneko, Syuichi; Miyazaki, Masaru; Iwama, Atsushi; Yokosuka, Osamu

    2014-01-01

    Tumor-initiating cells (TICs) play a central role in tumor development, metastasis, and recurrence. In the present study, we investigated the effect of disulfiram (DSF), an inhibitor of aldehyde dehydrogenase, toward tumor-initiating hepatocellular carcinoma (HCC) cells. DSF treatment suppressed the anchorage-independent sphere formation of both HCC cells. Flow cytometric analyses showed that DSF but not 5-fluorouracil (5-FU) drastically reduces the number of tumor-initiating HCC cells. The sphere formation assays of epithelial cell adhesion molecule (EpCAM)(+) HCC cells co-treated with p38-specific inhibitor revealed that DSF suppresses self-renewal capability mainly through the activation of reactive oxygen species (ROS)-p38 MAPK pathway. Microarray experiments also revealed the enrichment of the gene set involved in p38 MAPK signaling in EpCAM(+) cells treated with DSF but not 5-FU. In addition, DSF appeared to downregulate Glypican 3 (GPC3) in a manner independent of ROS-p38 MAPK pathway. GPC3 was co-expressed with EpCAM in HCC cell lines and primary HCC cells and GPC3-knockdown reduced the number of EpCAM(+) cells by compromising their self-renewal capability and inducing the apoptosis. These results indicate that DSF impaired the tumorigenicity of tumor-initiating HCC cells through activation of ROS-p38 pathway and in part through the downregulation of GPC3. DSF might be a promising therapeutic agent for the eradication of tumor-initiating HCC cells.

  5. Disulfiram Eradicates Tumor-Initiating Hepatocellular Carcinoma Cells in ROS-p38 MAPK Pathway-Dependent and -Independent Manners

    PubMed Central

    Yuki, Kaori; Zen, Yoh; Oshima, Motohiko; Miyagi, Satoru; Saraya, Atsunori; Koide, Shuhei; Motoyama, Tenyu; Ogasawara, Sadahisa; Ooka, Yoshihiko; Tawada, Akinobu; Nakatsura, Tetsuya; Hayashi, Takehiro; Yamashita, Taro; Kaneko, Syuichi; Miyazaki, Masaru; Iwama, Atsushi; Yokosuka, Osamu

    2014-01-01

    Tumor-initiating cells (TICs) play a central role in tumor development, metastasis, and recurrence. In the present study, we investigated the effect of disulfiram (DSF), an inhibitor of aldehyde dehydrogenase, toward tumor-initiating hepatocellular carcinoma (HCC) cells. DSF treatment suppressed the anchorage-independent sphere formation of both HCC cells. Flow cytometric analyses showed that DSF but not 5-fluorouracil (5-FU) drastically reduces the number of tumor-initiating HCC cells. The sphere formation assays of epithelial cell adhesion molecule (EpCAM)+ HCC cells co-treated with p38-specific inhibitor revealed that DSF suppresses self-renewal capability mainly through the activation of reactive oxygen species (ROS)-p38 MAPK pathway. Microarray experiments also revealed the enrichment of the gene set involved in p38 MAPK signaling in EpCAM+ cells treated with DSF but not 5-FU. In addition, DSF appeared to downregulate Glypican 3 (GPC3) in a manner independent of ROS-p38 MAPK pathway. GPC3 was co-expressed with EpCAM in HCC cell lines and primary HCC cells and GPC3-knockdown reduced the number of EpCAM+ cells by compromising their self-renewal capability and inducing the apoptosis. These results indicate that DSF impaired the tumorigenicity of tumor-initiating HCC cells through activation of ROS-p38 pathway and in part through the downregulation of GPC3. DSF might be a promising therapeutic agent for the eradication of tumor-initiating HCC cells. PMID:24454751

  6. Induction of Nur77-dependent apoptotic pathway by a coumarin derivative through activation of JNK and p38 MAPK.

    PubMed

    Zhou, Yuqi; Zhao, Wei; Xie, Guobin; Huang, Mingfeng; Hu, Mengjie; Jiang, Xin; Zeng, Dequan; Liu, Jie; Zhou, Hu; Chen, Haifeng; Wang, Guang-Hui; Zhang, Xiao-Kun

    2014-12-01

    Coumarins are plant-derived natural products with a broad range of known pharmacological activities including anticancer effects. However, the molecular mechanisms by which this class of promising compounds exerts their anticancer effects remain largely unknown. We report here that a furanocoumarin named apaensin could effectively induce apoptosis of cancer cells through its activation of Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Apoptosis induction by apaensin in cancer cells was suppressed by chemical inhibitors of JNK and p38 MAPK. Inhibition of the expression of orphan nuclear receptor Nur77 by small interfering RNA (siRNA) approach also abrogated the death effect of apaensin. Molecular analysis demonstrated that JNK activation was required for the nuclear export of Nur77, a known apoptotic event in cancer cells. Although p38 MAPK activation was not involved in Nur77 nuclear export, it was essential for Nur77 mitochondrial targeting through induction of Nur77 interaction with Bcl-2, which is also known to convert Bcl-2 from an antiapoptotic to a proapoptotic molecule. Together, our results identify a new natural product that targets orphan nuclear receptor Nur77 through its unique activation of JNK and p38 MAPK and provide insight into the complex regulation of the Nur77-Bcl-2 apoptotic pathway. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Induction of Nur77-dependent apoptotic pathway by a coumarin derivative through activation of JNK and p38 MAPK

    PubMed Central

    Zhou, Yuqi; Zhao, Wei; Xie, Guobin; Huang, Mingfeng; Hu, Mengjie; Jiang, Xin; Zeng, Dequan; Liu, Jie; Zhou, Hu; Chen, Haifeng; Zhang, Xiao-Kun

    2014-01-01

    Coumarins are plant-derived natural products with a broad range of known pharmacological activities including anticancer effects. However, the molecular mechanisms by which this class of promising compounds exerts their anticancer effects remain largely unknown. We report here that a furanocoumarin named apaensin could effectively induce apoptosis of cancer cells through its activation of Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Apoptosis induction by apaensin in cancer cells was suppressed by chemical inhibitors of JNK and p38 MAPK. Inhibition of the expression of orphan nuclear receptor Nur77 by small interfering RNA (siRNA) approach also abrogated the death effect of apaensin. Molecular analysis demonstrated that JNK activation was required for the nuclear export of Nur77, a known apoptotic event in cancer cells. Although p38 MAPK activation was not involved in Nur77 nuclear export, it was essential for Nur77 mitochondrial targeting through induction of Nur77 interaction with Bcl-2, which is also known to convert Bcl-2 from an antiapoptotic to a proapoptotic molecule. Together, our results identify a new natural product that targets orphan nuclear receptor Nur77 through its unique activation of JNK and p38 MAPK and provide insight into the complex regulation of the Nur77-Bcl-2 apoptotic pathway. PMID:25187486

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Mechanism of salutary effects of melatonin-mediated liver protection after trauma-hemorrhage: p38 MAPK-dependent iNOS/HIF-1α pathway.

    PubMed

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

    2017-05-01

    Although melatonin attenuates the increases in inflammatory mediators and reduces organ injury during trauma-hemorrhage, the mechanisms remain unclear. This study explored whether melatonin prevents liver injury after trauma-hemorrhage through the p38 mitogen-activated protein kinase (MAPK)-dependent, inducible nitrite oxide (iNOS)/hypoxia-inducible factor (HIF)-1α 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, melatonin (2 mg/kg), melatonin plus p38 MAPK inhibitor SB203580 (2 mg/kg), or melatonin plus the melatonin receptor antagonist luzindole (2.5 mg/kg). At 2 h after trauma-hemorrhage, histopathology score of liver injury, liver tissue myeloperoxidase activity, malondialdehyde, adenosine triphosphate, serum alanine aminotransferase, and asparate aminotransferase levels were significantly increased compared with sham-operated control. Trauma-hemorrhage resulted in a significant decrease in the p38 MAPK activation compared with that in the sham-treated animals. Administration of melatonin after trauma-hemorrhage normalized liver p38 MAPK phosphorylation and iNOS and HIF-1α expression and attenuated cleaved caspase 3 and receptor interacting protein kinase-1 levels. Coadministration of SB203580 or luzindole abolished the melatonin-mediated attenuation of the trauma-hemorrhage-induced increase of iNOS/HIF-1α protein expression and liver injury markers. Taken together, our results suggest that melatonin prevents trauma-hemorrhage-induced liver injury in rats, at least in part, through melatonin receptor-related, p38 MAPK-dependent iNOS/HIF-1α pathway.NEW & NOTEWORTHY Trauma-hemorrhage resulted in a significant decrease in liver p38 MAPK activation and increase in nitrite oxide synthase (iNOS) and hypoxia-inducible factor (HIF)-1α expression. Administration of melatonin after trauma

  14. Induction of interleukin-10 is dependent on p38 mitogen-activated protein kinase pathway in macrophages infected with porcine reproductive and respiratory syndrome virus

    PubMed Central

    2012-01-01

    Background Porcine reproductive and respiratory syndrome virus (PRRSV) causes reproductive failure and respiratory illness in pigs and usually establishes a persistent infection. Previous studies suggested that interleukin-10 (IL-10) could play a critical role in PRRSV-induced immunosuppression. However, the ability of PRRSV to induce IL-10 in infected cells is controversial. In this study, we further investigated this issue using PRRSV strain CH-1a, which is the first North American genotype strain isolated in China. Results PRRSV strain CH-1a could significantly up-regulate IL-10 production both at mRNA and protein levels in porcine alveolar macrophages (PAMs), bone marrow-derived macrophages (BMDMs), and monocyte-derived macrophages (MDMs). However, up-regulation of IL-10 by PRRSV was retarded by specific inhibitors of p38 mitogen-activated protein kinase (MAPK) (SB203580) and NF-κB (BAY11-7082). Additionally, p38 MAPK and NF-κB pathways but not ERK1/2 MAPK were actually activated in PRRSV-infected BMDMs as demonstrated by western blot analysis, suggesting that p38 MAPK and NF-κB pathways are involved in the induction of IL-10 by PRRSV infection. Transfection of PAMs and PAM cell line 3D4/21 (CRL-2843) with viral structural genes showed that glycoprotein5 (GP5) could significantly up-regulate IL-10 production, which was dependent on p38 MAPK and signal transducer and activator of transcription-3 (STAT3) activation. We also demonstrated that a full-length glycoprotein was essential for GP5 to induce IL-10 production. Conclusions PRRSV strain CH-1a could significantly up-regulate IL-10 production through p38 MAPK activation. PMID:22909062

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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

  2. Carnosic acid (CA) attenuates collagen-induced arthritis in db/db mice via inflammation suppression by regulating ROS-dependent p38 pathway.

    PubMed

    Xia, Guangtao; Wang, Xia; Sun, Hongsheng; Qin, Yuhong; Fu, Min

    2017-07-01

    Rheumatoid arthritis (RA) is a multifactorial autoimmune disease, characterized by inflammation of synovial joints. Carnosic acid (CA) is a phenolic diterpene isolated from Rosmarinus officinailis, playing a central role in cytoprotective responses to oxidative stress and inflammation response. Our study aimed to investigate the effects of CA on RA progression in diabetic animals. Carnosic acid (CA) was used to treat collagen-induced arthritis (CIA)-induced db/db mice. Blood glucose, oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were investigated to explore insulin resistance. CA significantly down-regulated fasting blood glucose, glucose level in OGTT and ITT, ameliorated CIA-induced bone loss, and reduced pro-inflammatory cytokines and reactive oxygen species (ROS) in db/db mice with arthritis induced by CIA. In vitro, CA suppressed Receptor Activator for Nuclear Factor-κ B Ligand (RANKL)- and Macrophage colony-stimulating factor (M-CSF)-induced osteoclastogenesis. The osteoclastic specific markers were inhibited by CA. Signal transduction studies showed that CA significantly decreased the expression of molecules contributing to ROS and increased anti-oxidants. Additionally, CA inactivated the RANKL- and M-CSF-induced p38 mitogen activated protein kinases (MAPK), inhibited NF-κB phosphorylation, causing pro-inflammatory cytokines down-regulation. Together, CA ameliorated osteoclast formation and CIA-induced bone loss in db/db mice through inflammation suppression by regulating ROS-dependent p38 pathway. Copyright © 2017. Published by Elsevier Inc.

  3. 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.

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

    PubMed

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

    2016-09-01

    Chondrosarcoma is the second most frequently occurring type of bone malignancy characterized by distant metastatic propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumour lymphangiogenesis and lymphatic metastasis. Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes. In recent years, adiponectin has also been indicated as facilitating tumorigenesis, angiogenesis and metastasis. However, the effect of adiponectin on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has remained largely a mystery. In the present study, we have shown a clinical correlation between adiponectin and VEGF-C, as well as tumour stage, in human chondrosarcoma tissues. We further demonstrated that adiponectin promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium from adiponectin-treated cells significantly induced tube formation and migration of human lymphatic endothelial cells. In addition, adiponectin knock down inhibited lymphangiogenesis in vitro and in vivo We also found that adiponectin-induced VEGF-C is mediated by the calmodulin-dependent protein kinase II (CaMKII), AMP-activated protein kinase (AMPK) and p38 signaling pathway. Furthermore, the expression of miR-27b was negatively regulated by adiponectin via the CaMKII, AMPK and p38 cascade. The present study is the first to describe the mechanism of adiponectin-promoted lymphangiogenesis by up-regulating VEGF-C expression in chondrosarcomas. Thus, adiponectin could serve as a therapeutic target in chondrosarcoma metastasis and lymphangiogenesis. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  5. Imatinib Reverses Doxorubicin Resistance by Affecting Activation of STAT3-Dependent NF-κB and HSP27/p38/AKT Pathways and by Inhibiting ABCB1

    PubMed Central

    Sims, Jonathan T.; Ganguly, Sourik S.; Bennett, Holly; Friend, J. Woodrow; Tepe, Jessica; Plattner, Rina

    2013-01-01

    Despite advances in cancer detection and prevention, a diagnosis of metastatic disease remains a death sentence due to the fact that many cancers are either resistant to chemotherapy (conventional or targeted) or develop resistance during treatment, and residual chemoresistant cells are highly metastatic. Metastatic cancer cells resist the effects of chemotherapeutic agents by upregulating drug transporters, which efflux the drugs, and by activating proliferation and survival signaling pathways. Previously, we found that c-Abl and Arg non-receptor tyrosine kinases are activated in breast cancer, melanoma, and glioblastoma cells, and promote cancer progression. In this report, we demonstrate that the c-Abl/Arg inhibitor, imatinib (imatinib mesylate, STI571, Gleevec), reverses intrinsic and acquired resistance to the anthracycline, doxorubicin, by inducing G2/M arrest and promoting apoptosis in cancer cells expressing highly active c-Abl and Arg. Significantly, imatinib prevents intrinsic resistance by promoting doxorubicin-mediated NF-κB/p65 nuclear localization and repression of NF-κB targets in a STAT3-dependent manner, and by preventing activation of a novel STAT3/HSP27/p38/Akt survival pathway. In contrast, imatinib prevents acquired resistance by inhibiting upregulation of the ABC drug transporter, ABCB1, directly inhibiting ABCB1 function, and abrogating survival signaling. Thus, imatinib inhibits multiple novel chemoresistance pathways, which indicates that it may be effective in reversing intrinsic and acquired resistance in cancers containing highly active c-Abl and Arg, a critical step in effectively treating metastatic disease. Furthermore, since imatinib converts a master survival regulator, NF-κB, from a pro-survival into a pro-apoptotic factor, our data suggest that NF-κB inhibitors may be ineffective in sensitizing tumors containing activated c-Abl/Arg to anthracyclines, and instead might antagonize anthracycline-induced apoptosis. PMID:23383209

  6. Endogenous N-acyl-dopamines induce COX-2 expression in brain endothelial cells by stabilizing mRNA through a p38 dependent pathway.

    PubMed

    Navarrete, Carmen M; Pérez, Moisés; de Vinuesa, Amaya García; Collado, Juan A; Fiebich, Bernd L; Calzado, Marco A; Muñoz, Eduardo

    2010-06-15

    Cerebral microvascular endothelial cells play an active role in maintaining cerebral blood flow, microvascular tone and blood brain barrier (BBB) functions. Endogenous N-acyl-dopamines like N-arachidonoyl-dopamine (NADA) and N-oleoyl-dopamine (OLDA) have been recently identified as a new class of brain neurotransmitters sharing endocannabinoid and endovanilloid biological activities. Endocannabinoids are released in response to pathogenic insults and may play an important role in neuroprotection. In this study we demonstrate that NADA differentially regulates the release of PGE(2) and PGD(2) in the microvascular brain endothelial cell line, b.end5. We found that NADA activates a redox-sensitive p38 MAPK pathway that stabilizes COX-2 mRNA resulting in the accumulation of the COX-2 protein, which depends on the dopamine moiety of the molecule and that is independent of CB(1) and TRPV1 activation. In addition, NADA inhibits the expression of mPGES-1 and the release of PGE(2) and upregulates the expression of L-PGD synthase enhancing PGD(2) release. Hence, NADA and other molecules of the same family might be included in the group of lipid mediators that could prevent the BBB injury under inflammatory conditions and our findings provide new mechanistic insights into the anti-inflammatory activities of NADA in the central nervous system and its potential to design novel therapeutic strategies to manage neuroinflammatory diseases. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Sin1 binds to both ATF-2 and p38 and enhances ATF-2-dependent transcription in an SAPK signaling pathway.

    PubMed

    Makino, Chieko; Sano, Yuji; Shinagawa, Toshie; Millar, Jonathan B A; Ishii, Shunsuke

    2006-11-01

    Yeast Sin1 binds to the Sty1 kinase, a member of the stress-activated kinases (SAPKs), and is required for stress-induced phosphorylation and activation of the transcription factor Atf1, a homolog of the vertebrate-activating transcription factor-2 (ATF-2). Here we report that mammalian Sin1 plays an important role in the SAPK signaling pathway by binding to both ATF-2 and p38. In response to stress, ATF-2, a member of the ATF/cAMP response element-binding protein family, is phosphorylated by p38/Jun NH2-terminal protein kinase and activates the transcription of apoptosis-related genes. In contrast, in response to serum stimulation, ATF-2 is phosphorylated via the Ras effector pathway and leads to the induction of growth-related genes. We found that Sin1 binds directly to both ATF-2 and p38. Sin1 over-expression enhanced osmotic stress-induced phosphorylation of ATF-2 and ATF-2-mediated transcription, whereas knockdown of Sin1 expression by siRNA suppressed these responses. Moreover, a reduction in Sin1 expression suppressed osmotic stress-induced apoptosis and the expression of Gadd45beta, one of the ATF-2 target genes that is correlated with apoptosis. Decreased Sin1 expression, however, did not affect the serum stimulation-induced phosphorylation of ATF-2. Sin1 may contribute to ATF-2 signaling specificity by acting as a nuclear scaffold.

  8. 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.

  9. Apoptosis Signal-regulating Kinase 1 (ASK1)-p38 Pathway-dependent Cytoplasmic Translocation of the Orphan Nuclear Receptor NR4A2 Is Required for Oxidative Stress-induced Necrosis.

    PubMed

    Watanabe, Takeshi; Sekine, Shiori; Naguro, Isao; Sekine, Yusuke; Ichijo, Hidenori

    2015-04-24

    p38 mitogen-activated protein kinases (MAPKs) play important roles in various cellular stress responses, including cell death, which is roughly categorized into apoptosis and necrosis. Although p38 signaling has been extensively studied, the molecular mechanisms of p38-mediated cell death are unclear. ASK1 is a stress-responsive MAP3K that acts as an upstream kinase of p38 and is activated by various stresses, such as oxidative stress. Here, we show that NR4A2, a member of the NR4A nuclear receptor family, acts as a necrosis promoter downstream of ASK1-p38 pathway during oxidative stress. Although NR4A2 is well known as a nucleus-localized transcription factor, we found that it is translocated into the cytosol after phosphorylation by p38. Because the phosphorylation site mutants of NR4A2 cannot rescue the cell death-promoting activity, ASK1-p38 pathway-dependent phosphorylation and subsequent cytoplasmic translocation of NR4A2 may be required for oxidative stress-induced cell death. In addition, NR4A2-mediated cell death does not depend on caspases and receptor-interacting protein 1 (RIP1)-RIP3 complex, suggesting that NR4A2 promotes an RIP kinase-independent necrotic type of cell death. Our findings may enable a more precise understanding of molecular mechanisms that regulate oxidative stress-induced and p38-mediated necrosis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    PubMed Central

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

    2016-01-01

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

  11. A stress-activated, p38 mitogen-activated protein kinase-ATF/CREB pathway regulates posttranscriptional, sequence-dependent decay of target RNAs.

    PubMed

    Gao, Jun; Wagnon, Jacy L; Protacio, Reine M; Glazko, Galina V; Beggs, Marjorie; Raj, Vinay; Davidson, Mari K; Wahls, Wayne P

    2013-08-01

    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.

  12. 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

  13. Induction of oxidative metabolism by the p38α/MK2 pathway.

    PubMed

    Trempolec, Natalia; Muñoz, Juan Pablo; Slobodnyuk, Konstantin; Marin, Silvia; Cascante, Marta; Zorzano, Antonio; Nebreda, Angel R

    2017-09-12

    Adequate responses to environmental stresses are essential for cell survival. The regulation of cellular energetics that involves mitochondrial energy production and oxidative stress is central in the process of stress adaptation and response. The p38α signalling pathway plays a key role in the response to stress stimuli by orchestrating multiple cellular processes. However, prolonged activation of the p38α pathway results in impaired cell proliferation and can lead to cell death. Here we use a system to specifically activate p38α signalling and show that sustained activation of this pathway suffices to induce important metabolic changes, including high dependence on glucose for cell survival, increased consumption of glutamine, enhanced respiration rate and elevated production of mitochondrial reactive oxygen species (ROS). Moreover, we provide evidence that increased production of mitochondrial superoxide as a consequence of elevated mitochondria activity, contributes to the p38α reduced cell survival triggered by sustained p38α activation. We also show that the p38α-activated kinase MAPKAPK2 (MK2) plays an important role orchestrating the observed metabolic changes. Our results illustrate a new function of p38α signalling in the regulation of cellular metabolism, which may lead to cell death upon persistent activation of the pathway.

  14. 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

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

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

    PubMed Central

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

    2015-01-01

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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Arctigenin induces apoptosis in colon cancer cells through ROS/p38MAPK pathway.

    PubMed

    Li, Qing-chun; Liang, Yun; Tian, Yuan; Hu, Guang-rui

    2016-01-01

    In the current study the antiproliferative effect of arctigenin, plant lignin, was evaluated on human colon cancer cell line HT-29. Furthermore, attempts were made to explore the signaling mechanism which may be responsible for its effect. Cell growth inhibition was assessed by MTT and LDH assays. Flow cytometric analysis was performed to determine cell arrest in the cell cycle phase and apoptosis. Furthermore, to confirm the apoptotic activity of arctigenin, caspase-9 and -3 activities analysis was performed. The levels of reactive oxygen species (ROS) and p38 mitogen activated protein kinase (MAPK) were investigated to determine their role in inducing apoptosis in arctigenin-treated HT-29 colon cancer cell line. MTT and LDH results demonstrated significant cell growth inhibitory effect of arctigenin on HT-29 cells in a dose-dependent manner. Furthermore, increase in cell number arrested at G2/M phase was observed in flow cytometric analysis upon arctigenin treatment. In addition, arctigenin increased the apoptotic ratio in a dose-dependent manner. The involvement of intrinsic apoptotic pathway was indicated by the activation of caspase-9 and -3. Moreover, increased ROS production, activation of p38 MAPK and changes in mitochondrial membrane potential (ΔΨm) also revealed the role of intrinsic apoptotic signaling pathway in cell growth inhibition after arctigenin exposure. Arctigenin induces apoptosis in HT-29 colon cancer cells by regulating ROS and p38 MAPK pathways.

  8. Resistin Promotes Intervertebral Disc Degeneration by Upregulation of ADAMTS-5 Through p38 MAPK Signaling Pathway.

    PubMed

    Liu, Caijun; Yang, Hao; Gao, Fei; Li, Xiang; An, Yan; Wang, Jianru; Jin, Anmin

    2016-09-15

    Rat nucleus pulposus (NP) cells were activated with resistin with or without p38 mitogen-activated protein kinase (MAPK) pathway inhibition. The expression of a disintegrin and metalloprotease with thrombospondin motif-5 (ADAMTS-5), which plays an important role in intervertebral disc degeneration (IDD), was determined. The aim of this study was to demonstrate whether resistin can influence the ADAMTS-5 expression and to further investigate the underlying mechanisms. Obesity has been demonstrated to promote IDD, whereas the exact mechanism remains poorly understood. Resistin, as an important adipokine, is increased with obesity and has been shown to play pro-inflammatory and catabolic role in cartilage metabolism. However, the effect of resistin on the catabolic enzymes within NP cells remains unknown. We exposed NP cells to resistin, and the transcriptional activity, gene expression, and protein levels of ADAMTS-5 were measured by luciferase reporter assay, qRT-polymerase chain reaction, immunofluorescence, and western blot, respectively. The activation of p38 MAPK pathways was detected using western blot analysis. Resistin had no effect on cell viability. Resistin increased ADAMTS-5 expression in rat NP cells time and dose dependently. The p38 MAPK signaling pathway was activated after exposure to resistin. Treatment with p38 inhibitor decreased the upregulation of ADAMTS-5 by resistin. The current study, for the first time, investigated the role of resistin in ADAMTS-5 regulation in IDD. These findings provide novel evidence supporting the causative role of obesity in IDD, which is important to develop novel preventative or therapeutic treatment in disc degenerative disorders. N/A.

  9. Rotenone Directly Induces BV2 Cell Activation via the p38 MAPK Pathway

    PubMed Central

    Gao, Feng; Chen, Dong; Hu, Qingsong; Wang, Guanghui

    2013-01-01

    Parkinson’s disease (PD) is the second most common neurodegenerative disease. Although its pathogenesis is still unclear, increasing evidence suggests that mitochondrial dysfunction induced by environmental toxins, such as mitochondrial complex I inhibitors, plays a significant role in the disease process. The microglia in PD brains are highly activated, and inflammation is also an essential element in PD pathogenesis. However, the means by which these toxins activate microglia is still unclear. In the present study, we found that rotenone, a mitochondrial complex I inhibitor, could directly activate microglia via the nuclear factor kappa B (NF-κB) signaling pathway, thereby inducing significantly increased expression of inflammatory cytokines. We further observed that rotenone induced caspase-1 activation and mature IL-1β release, both of which are strictly dependent on p38 mitogen-activated protein kinase (MAPK). The activation of p38 is associated with the presence of reactive oxygen species (ROS) produced by rotenone. Removal of these ROS abrogated the activation of the microglia. Therefore, our data suggest that the environmental toxin rotenone can directly activate microglia through the p38 MAPK pathway. PMID:23977201

  10. 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

  11. 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

  12. 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.

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

    PubMed

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

    2014-07-18

    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 (CdCl2) on human umbilical vein endothelial cells (HUVECs). At 4 μM, CdCl2 induced a hyper-permeability defect in HUVECs, but not the inhibition of cell growth up to 24h. This effect of CdCl2 was dependent on the activation of the p38 mitogen-activated protein kinase (MAPK) pathway. The p38 MAPK inhibitor SB203850 suppressed the CdCl2-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. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Desferrioxamine (DFX) induces apoptosis through the p38-caspase8-Bid-Bax pathway in PHA-stimulated human lymphocytes

    SciTech Connect

    Kim, Byeong-Mo; Chung, Hai-Won

    2008-04-01

    Desferrioxamine (DFX) induces apoptosis in human lymphocytes, although the mechanism leading to cell death is unclear. Therefore, we investigated the signaling pathways implicated in DFX-induced apoptosis in lymphocytes. DFX treatment activated caspase-9, caspase-3, and caspase-8. DFX-induced apoptosis was inhibited by both z-IETD-fmk and z-DEVD-fmk. DFX treatment also enhanced caspase-8 activity, Bid cleavage, and the conformational activation of Bax. DFX treatment activated two MAPKs, p38 and JNK, and induced the phosphorylation of two proteins in the p38 pathway, MKK3 and MKK6. DFX treatment also increased the phosphorylation of two downstream targets of p38, ATF-2 and MAPKAPK2, indicating that DFX promotes p38 activity. In addition, the selective p38 inhibitor SB203580 suppressed DFX-induced apoptosis and caspase-8 activation, whereas the JNK inhibitor, SP600125, and the ERK inhibitor, PD98059, had no effect. Our results suggest that DFX-induced apoptosis is mediated by the p38 pathway and a caspase-8-dependent Bid-Bax pathway in human lymphocytes.

  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. 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.

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

    PubMed Central

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

    2016-01-01

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

  18. 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.

  19. Pancreatic Cancer Sensitive to Selective p38 Pathway Inhibition | Center for Cancer Research

    Cancer.gov

    Pancreatic ductal adenocarcinoma (PDAC), the most-common cancer of the pancreas, is an aggressive disease that is estimated by the American Cancer Society to be the fourth leading cause of cancer death in men and women in 2015. Like most solid tumors, PDAC is surrounded by an inflammatory microenvironment containing numerous infiltrating immune cells. These cells are unable to eliminate the tumor and instead create a hospitable environment by providing tumor growth-promoting cytokines, the production of which lies downstream of the kinase p38. Unlike most immune cells, which use the classical pathway to activate p38, T cells employ an alternative p38 pathway that involves phosphorylation of tyrosine 323 (pY323) by the T cell receptor. Jonathan Ashwell, M.D., of CCR’s Laboratory of Immune Cell Biology and his colleagues decided to assess the role of the alternative p38 pathway in pancreatic cancer.

  20. 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.

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

    PubMed Central

    Paillas, Salomé; Boissière, Florence; Bibeau, Frédéric; 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

    2011-01-01

    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 to 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 β, 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 to non-responder 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. PMID:21159664

  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. 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.

  4. 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

  5. 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.

  6. Differential p38-dependent signalling in response to cellular stress and mitogenic stimulation in fibroblasts

    PubMed Central

    2012-01-01

    p38 MAP kinase is known to be activated by cellular stress finally leading to cell cycle arrest or apoptosis. Furthermore, a tumour suppressor role of p38 MAPK has been proposed. In contrast, a requirement of p38 for proliferation has also been described. To clarify this paradox, we investigated stress- and mitogen-induced p38 signalling in the same cell type using fibroblasts. We demonstrate that - in the same cell line - p38 is activated by mitogens or cellular stress, but p38-dependent signalling is different. Exposure to cellular stress, such as anisomycin, leads to a strong and persistent p38 activation independent of GTPases. As a result, MK2 and downstream the transcription factor CREB are phosphorylated. In contrast, mitogenic stimulation results in a weaker and transient p38 activation, which upstream involves small GTPases and is required for cyclin D1 induction. Consequently, the retinoblastoma protein is phosphorylated and allows G1/S transition. Our data suggest a dual role of p38 and indicate that the level and/or duration of p38 activation determines the cellular response, i.e either proliferation or cell cycle arrest. PMID:22404972

  7. 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

  8. 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

  9. 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

  10. 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

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

    PubMed Central

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

    2014-01-01

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

  12. Regulation of Hippo pathway transcription factor TEAD by p38 MAPK-induced cytoplasmic translocation.

    PubMed

    Lin, Kimberly C; Moroishi, Toshiro; Meng, Zhipeng; Jeong, Han-Sol; Plouffe, Steven W; Sekido, Yoshitaka; Han, Jiahuai; Park, Hyun Woo; Guan, Kun-Liang

    2017-07-28

    The Hippo pathway controls organ size and tissue homeostasis, with deregulation leading to cancer. The core Hippo components in mammals are composed of the upstream serine/threonine kinases Mst1/2, MAPK4Ks and Lats1/2. Inactivation of these upstream kinases leads to dephosphorylation, stabilization, nuclear translocation and thus activation of the major functional transducers of the Hippo pathway, YAP and its paralogue TAZ. YAP/TAZ are transcription co-activators that regulate gene expression primarily through interaction with the TEA domain DNA-binding family of transcription factors (TEAD). The current paradigm for regulation of this pathway centres on phosphorylation-dependent nucleocytoplasmic shuttling of YAP/TAZ through a complex network of upstream components. However, unlike other transcription factors, such as SMAD, NF-κB, NFAT and STAT, the regulation of TEAD nucleocytoplasmic shuttling has been largely overlooked. In the present study, we show that environmental stress promotes TEAD cytoplasmic translocation via p38 MAPK in a Hippo-independent manner. Importantly, stress-induced TEAD inhibition predominates YAP-activating signals and selectively suppresses YAP-driven cancer cell growth. Our data reveal a mechanism governing TEAD nucleocytoplasmic shuttling and show that TEAD localization is a critical determinant of Hippo signalling output.

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

    PubMed

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

    2009-11-01

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

  14. 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

  15. [Effect of melatonin on p38MAPKsignaling pathway in rats with phosgene-induced lung injury].

    PubMed

    Zhang, Lin; He, Daikun; Shao, Yiru; Xu, Daojian; Shen, Jie

    2014-09-01

    To investigate the effect of melatonin (MT) on p38 mitogen-activated protein kinase (MAPK) signaling pathway in rats with phosgene-induced lung injury. Fifty specific pathogen-free male Sprague-Dawley rats were randomly divided into phosgene inhalation group, air control group, saline control group, MT treatment group, and SB203580 (specific inhibitor of p38 MAPK) group, with 10 mice in each group. All groups except the air control group were exposed to phosgene, and the animals were sacrificed 6 h later. Lung wet/dry weight (W/D) ratio and the content of malondialdehyde (MDA) and nitric oxide (NO) and activity of myeloperoxidase (MPO) in bronchoalveolar lavage fluid (BALF) were measured. The qualitative and quantitative expression of p38 MAPK and phospho-p38 MAPK (p-p38) was measured by immunohistochemistry (IHC) and Western blot, respectively. Inducible nitric oxide synthase (iNOS) level in lung tissue was determined by Western blot. Compared with the air control group, the phosgene inhalation group had significantly increased lung W/D ratio and neutrophil count in BALF (P < 0.01); the MT treatment group had significantly lower neutrophil count and lung W/D ratio than the phosgene inhalation group (P < 0.05). IHC demonstrated that the air control group had relatively weak expression of p-p38 in lung tissue; the expression of p-p38 was significantly up-regulated after phosgene inhalation, and it was mainly distributed in infiltrating inflammatory cells and vascular endothelial cells, positive in the cytoplasm and nucleus of many cells. The distribution of p-p38-positive cells in the MT treatment and SB203580 groups was similar to that in the phosgene inhalation group, but the MT treatment and SB203580 groups had a significantly reduced number of cells with p-p38-positive nuclei and a significantly reduced intensity of p-p38 expression signals. The phosgene inhalation group had significantly increased content of MDA and NO and activity of MPO compared with the air

  16. 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

  17. 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.

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

    PubMed

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

    2016-01-01

    Previously, we found that electromagnetic pulses (EMP) induced an increase in blood brain barrier permeability and the leakage of albumin from blood into brain tissue. Albumin is known to activate microglia cells. Thus, we hypothesised that microglia activation could occur in the brain after EMP exposure. To test this hypothesis, the morphology and secretory function of microglia cells, including the expression of OX-42 (a marker of microglia activation), and levels of TNF-α, IL-10, IL-1β, and NO were determined in the rat cerebral cortex after EMP exposure. In addition, to examine the signalling pathway of EMP-induced microglia activation, protein and phosphorylated protein levels of p38, JNK and ERK were determined. It was found that the expression of OX-42increased significantly at 1, 6 and 12h (p<0.05) and recovered to the sham group level at 24h after EMP exposure. Levels of NO, TNF-α and IL-10 also changed significantly in vivo and in vitro after EMP exposure. The protein level of p38 and phosphorylated p38 increased significantly after EMP exposure (p<0.05) and recovered to sham levels at 12 and 24h, respectively. Protein and phosphorylated protein levels of ERK and JNK did not change. SB203580 (p38 inhibitor) partly prevented the change in NO, IL-10, IL-1β, TNF-α levels induced by EMP exposure. Taken together, these results suggested that EMP exposure (200kV/m, 200 pulses) could activate microglia in rat brain and affect its secretory function both in vivo and in vitro, and the p38 pathway is involved in this process. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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

  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. 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

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

    PubMed

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

    2015-06-30

    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.

  11. RUNX1 Regulates Migration, Invasion, and Angiogenesis via p38 MAPK Pathway in Human Glioblastoma.

    PubMed

    Sangpairoj, Kant; Vivithanaporn, Pornpun; Apisawetakan, Somjai; Chongthammakun, Sukumal; Sobhon, Prasert; Chaithirayanon, Kulathida

    2016-12-24

    Runt-related transcription factor 1 (RUNX1) is essential for the establishment of fetal and adult hematopoiesis and neuronal development. Aberrant expression of RUNX1 led to proliferation and metastasis of several cancers. The aim of the present study was to investigate the role of RUNX1 in migration, invasion, and angiogenesis of human glioblastoma using IL-1β-treated U-87 MG human glioblastoma cells as a model. IL-1β at 10 ng/ml stimulated translocation of RUNX1 into the nucleus with increased expressions of RUNX1, MMP-1, MMP-2, MMP-9, MMP-19, and VEGFA in U-87 MG cells. In addition, silencing of RUNX1 gene significantly suppressed U-87 MG cell migration and invasion abilities. Moreover, knockdown of RUNX1 mRNA in U-87 MG cells reduced the tube formation of human umbilical vein endothelial cells. Further investigation revealed that IL-1β-induced RUNX1 expression might be mediated via the p38 mitogen-activated protein kinase (MAPK) signaling molecule for the expression of these invasion- and angiogenic-related molecules. Together with an inhibitor of p38 MAPK (SB203580) could decrease RUNX1 mRNA expression. Thus, RUNX1 may be one of the putative molecular targeted therapies against glioma metastasis and angiogenesis through the activation of p38 MAPK signaling pathway.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. Anti-inflammatory role of Leptin in glial cells through p38 MAPK pathway inhibition.

    PubMed

    Patraca, Iván; Martínez, Nohora; Busquets, Oriol; Martí, Aleix; Pedrós, Ignacio; Beas-Zarate, Carlos; Marin, Miguel; Ettcheto, Miren; Sureda, Francesc; Auladell, Carme; Camins, Antoni; Folch, Jaume

    2017-06-01

    In the present work, we studied the modulatory effect of Leptin (Lep) against pro-inflammatory cytokines, tumour necrosis factor-alpha (TNFα), interleukin 1-beta (IL1β) and interferon-gamma (IFNγ), in primary glial cell cultures. Glial cultures were treated with pro-inflammatory cytokines (TNFα, 20ng/ml; IL1β, 20ng/ml; IFNγ 20ng/ml). Cells were pre-treated with Lep 500nM, 1h prior to cytokine treatment. NO released from glial cells was determined using the Griess reaction. Cell viability was determined by the MTT method. Protein expression was determined by western blot. Pre-treatment with 500nM Lep produced an inhibitory effect on inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production after glial cells exposure to pro-inflammatory cytokines. Anti-inflammatory effect can be related to a decrease in P38 MAP Kinase (MAPK) pathway activity. Treatment of glial cell cultures with Lep also reduced the intrinsic apoptotic pathway (cytochrome c release and caspase-3 activation). We suggest that Lep would act as an anti-inflammatory factor in glial cells exposed to pro-inflammatory cytokines, exerting its function on p38 MAPK pathway and reducing NO production. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  1. 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

  2. [Jianpi jiedu recipe inhibited Helicobacter pylori-induced the expression of cyclooxygenase-2 via p38MAPK/ATF-2 signal transduction pathway in human gastric cancer cells].

    PubMed

    Liu, Ning-ning; Wang, Yan; Wu, Qiong

    2011-07-01

    To study the effect of Jianpi Jiedu Recipe (JJR) on the expression of cyclooxygenase (COX-2) in Helicobacter pylori (Hp) infected gastric cancer cell line MKN 45, and its regulatory mechanism of p38MAPK signal transduction. The expressions of COX-2 mRNA and protein in human gastric cancer cell line MKN 45 infected by Hp type strain NCTC 11637 and the regulatory effect of JJR containing serum were detected using Real-time fluorescent quantitative polymerase chain reaction (RFQ-PCR) and Western blot. The effects of Hp on COX-2 mRNA and protein expressions in human gastric cancer cell line MKN 45 were observed using blocking p38MAPK signal transduction pathway by p38MAPK specific inhibitor SB203580. The effects of JJR on Hp-infection activated p38MAPK signal transduction pathway and its downstream activating transcription factor 2 (ATF-2) were observed. COX-2 mRNA and protein expressions were obviously higher after human gastric cancer cell line MKN 45 were infected by Hp (P<0.01). After blocking p38MAPK signal transduction pathway, COX-2 mRNA and protein expressions in Hp-induced MKN 45 cell line were obviously down-regulated (P<0.01). JJR containing serum down-regulated Hp-induced COX-2 mRNA and protein expressions in MKN 45 cell line in a dose dependent manner. Besides, it could inhibit the activation of Hp-induced p38MAPK signal pathway. It also showed obvious inhibition on the activity of its downstream transcription factor ATF-2. Hp infection induced COX-2 expressions of gastric cancer cells via p38MAPK signal transduction pathway. JJR inhibited Hp-induced the expression of COX-2 through regulating p38MAPK/ATF-2 signal transduction pathway, which may be one of its mechanisms in prevention and treatment of Hp-induced gastric cancer.

  3. Toxicarioside N induces apoptosis in human gastric cancer SGC-7901 cell by activating the p38MAPK pathway.

    PubMed

    Zhao, Huan-Ge; Zhou, Song-Lin; Lin, Ying-Ying; Dai, Hao-Fu; Huang, Feng-Ying

    2017-09-22

    Natural plant compounds with potent proliferation inhibition and apoptosis induction properties have been screened as novel anticancer drugs. Toxicarioside N (Tox N) was isolated from the seeds of the tropical plant Antiaris toxicaria in Hainan province, China. To our knowledge, the effects that Tox N has on the apoptosis of SGC-7901 cells and its potential mechanism have never been investigated. In this study, we detected the anticancer activities of Tox N and explored the potential mechanism in the human gastrointestinal cancer cell line SGC-7901. Here, we found that Tox N inhibited SGC-7901 cell growth in a dose- and time-dependent manner and induced apoptosis in cells based on cell morphology and flow cytometry analyses. Additionally, the SGC-7901 cell treated with Tox N up-regulated the expression level of cleaved caspase-3/9 and PARP, increased the Bax/Bcl-2 ratio, and led to the release of cytochrome c into the cytoplasm. In addition, Tox N treatment led to the phosphorylation of p38MAPK. SB203580, a p38MAPK inhibitor, partially attenuated Tox N induced apoptosis by preventing the activation of caspase-3/9 and PARP. Our results indicated for the first time that Tox N can induce SGC-7901 cells apoptosis by activating the p38MAPK pathway.

  4. 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.

  5. Activation of p38 MAP Kinase and JNK Pathways by UVA Irradiation

    PubMed Central

    Zhang, Jack; Bowden, G. Tim

    2014-01-01

    There are more than two million new cases of non-melanoma skin cancers (NMSCs) diagnosed each year in the United States. The clear etiological factor is chronic exposure to solar radiation from the sun. The wavelengths of solar light that reach the earth’s surface include UVB (280-320nm) which accounts for 1-10% and UVA (320-400nm) which accounts for 90-99% of the radiation. While most of the published research has focused on the effects of UVB, little is known concerning UVA-mediated signal transduction pathways and their role in skin tumor promotion and progression giving rise to squamous cell carcinomas (SCCs). Here we have focused on UVA-mediated activation of p38 MAP kinase and c-Jun N-terminal kinase (JNK) and their roles in activator protein-1 (AP-1) mediated transcription, cyclooxygenase-2 (COX-2) and Bcl-XL expression. Since p38 MAP kinase and JNK play major roles in the expression of UVA-induced AP-1, COX-2 and Bcl-XL, pharmacological inhibitors of these kinases may be useful in the chemoprevention of SCC skin cancer. PMID:21858326

  6. 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

  7. Adiponectin impairs chicken preadipocytes differentiation through p38 MAPK/ATF-2 and TOR/p70 S6 kinase pathways.

    PubMed

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

    2013-01-01

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

  8. 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

  9. 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.

  10. 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.

  11. Astragalus Polysaccharide Suppresses Doxorubicin-Induced Cardiotoxicity by Regulating the PI3k/Akt and p38MAPK Pathways

    PubMed Central

    Cao, Yuan; Ruan, Yang; Shen, Tao; Huang, Xiuqing; Li, Meng; Yu, Weiwei; Zhu, Yuping; Man, Yong; Wang, Shu; Li, Jian

    2014-01-01

    Background. Doxorubicin, a potent chemotherapeutic agent, is associated with acute and chronic cardiotoxicity, which is cumulatively dose-dependent. Astragalus polysaccharide (APS), the extract of Astragalus membranaceus with strong antitumor and antiglomerulonephritis activity, can effectively alleviate inflammation. However, whether APS could ameliorate chemotherapy-induced cardiotoxicity is not understood. Here, we investigated the protective effects of APS on doxorubicin-induced cardiotoxicity and elucidated the underlying mechanisms of the protective effects of APS. Methods. We analyzed myocardial injury in cancer patients who underwent doxorubicin chemotherapy and generated a doxorubicin-induced neonatal rat cardiomyocyte injury model and a mouse heart failure model. Echocardiography, reactive oxygen species (ROS) production, TUNEL, DNA laddering, and Western blotting were performed to observe cell survival, oxidative stress, and inflammatory signal pathways in cardiomyocytes. Results. Treatment of patients with the chemotherapeutic drug doxorubicin led to heart dysfunction. Doxorubicin reduced cardiomyocyte viability and induced C57BL/6J mouse heart failure with concurrent elevated ROS generation and apoptosis, which, however, was attenuated by APS treatment. In addition, there was profound inhibition of p38MAPK and activation of Akt after APS treatment. Conclusions. These results demonstrate that APS could suppress oxidative stress and apoptosis, ameliorating doxorubicin-mediated cardiotoxicity by regulating the PI3k/Akt and p38MAPK pathways. PMID:25386226

  12. 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

  13. Stress-induced phosphorylation of STAT1 at Ser727 requires p38 mitogen-activated protein kinase whereas IFN-γ uses a different signaling pathway

    PubMed Central

    Kovarik, Pavel; Stoiber, Dagmar; Eyers, Patrick A.; Menghini, Rossella; Neininger, Armin; Gaestel, Matthias; Cohen, Philip; Decker, Thomas

    1999-01-01

    STAT1 is an essential transcription factor for macrophage activation by IFN-γ and requires phosphorylation of the C-terminal Ser727 for transcriptional activity. In macrophages, Ser727 phosphorylation in response to bacterial lipopolysaccharide (LPS), UV irradiation, or TNF-α occurred through a signaling path sensitive to the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB203580 whereas IFN-γ-mediated Ser727 phosphorylation was not inhibited by the drug. Consistently, SB203580 did not affect IFN-γ-mediated, Stat1-dependent transcription but inhibited its enhancement by LPS. Furthermore, LPS, UV irradiation, and TNF-α caused activation of p38 MAPK whereas IFN-γ did not. An essential role for p38 MAPK activity in STAT1 Ser727 phosphorylation was confirmed by using cells expressing an SB203580-resistant p38 MAPK. In such cells, STAT1 Ser727 phosphorylation in response to UV irradiation was found to be SB203580 insensitive. Targeted disruption of the mapkap-k2 gene, encoding a kinase downstream of p38 MAPK with a key role in LPS-stimulated TNF-α production and stress-induced heat shock protein 25 phosphorylation, was without a significant effect on UV-mediated Ser727 phosphorylation. The recombinant Stat1 C terminus was phosphorylated in vitro by p38MAPKα and β but not by MAPK-activated protein kinase 2. Janus kinase 2 activity, previously reported to be required for IFN-γ-mediated Ser727 phosphorylation, was not needed for LPS-mediated Ser727 phosphorylation, and activation of Janus kinase 2 did not cause the appearance of STAT1 Ser727 kinase activity. Our data suggest that STAT1 is phosphorylated at Ser727 by a stress-activated signaling pathway either through p38 MAPK directly or through an unidentified kinase downstream of p38MAPK. PMID:10570180

  14. 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

  15. 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

  16. 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.

  17. 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

  18. HMGB1 promotes a p38MAPK associated non-infectious inflammatory response pathway in human fetal membranes.

    PubMed

    Bredeson, Sarah; Papaconstantinou, John; Deford, James H; Kechichian, Talar; Syed, Tariq A; Saade, George R; Menon, Ramkumar

    2014-01-01

    Spontaneous preterm birth (PTB) and preterm prelabor rupture of membranes (pPROM) are major pregnancy complications often associated with a fetal inflammatory response. Biomolecular markers of this fetal inflammatory response to both infectious and non-infectious risk factors and their contribution to PTB and pPROM mechanism are still unclear. This study examined fetal membrane production, activation and mechanistic properties of high mobility group box 1 (HMGB1) as a contributor of the non-infectious fetal inflammatory response. HMGB1 transcripts and active HMGB1 were profiled in fetal membranes and amniotic fluids collected from PTB and normal term birth. In vitro, normal term not in labor fetal membranes were exposed to lipopolysaccharide (LPS) and water soluble cigarette smoke extract (CSE). HMGB1-transcripts and its protein concentrations were documented by RT-PCR and ELISA. Recombinant HMGB1 treated membranes and media were subjected to RT-PCR for HMGB1 receptors, mitogen activated protein kinase pathway analysis, cytokine levels, and Western blot for p38MAPK. HMGB1 expression and its active forms were higher in PTB and pPROM than normal term membranes and amniotic fluid samples. Both LPS and CSE enhanced HMGB1 expression and release in vitro. Fetal membrane exposure to HMGB1 resulted in increased expression of TLR2 and 4 and dose-dependent activation of p38MAPK-mediated inflammation. HMGB1 increase by fetal membrane cells in response to either oxidative stress or infection can provide a positive feedback loop generating non-infectious inflammatory activation. Activation of p38MAPK by HMGB1 promotes development of the senescence phenotype and senescence associated sterile inflammation. HMGB1 activity is an important regulator of the fetal inflammatory response regardless of infection.

  19. 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

  20. 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

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

    PubMed

    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.

  2. 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.

  3. Aged dominant negative p38α MAPK mice are resistant to age-dependent decline in adult-neurogenesis and context discrimination fear conditioning.

    PubMed

    Cortez, IbDanelo; Bulavin, Dmitry V; Wu, Ping; McGrath, Erica L; Cunningham, Kathryn A; Wakamiya, Maki; Papaconstantinou, John; Dineley, Kelly T

    2017-03-30

    A major aspect of mammalian aging is the decline in functional competence of many self-renewing cell types, including adult-born neuronal precursors. Since age-related senescence of self-renewal occurs simultaneously with chronic up-regulation of the p38MAPKalpha (p38α) signaling pathway, we used the dominant negative mouse model for attenuated p38α activity (DN-p38α(AF/+)) in which Thr180 and Tyr182 are mutated (T→A/Y→F) to prevent phosphorylation activation (DN-p38α(AF/+)) and kinase activity. As a result, aged DN-p38α(AF/+) mice are resistant to age-dependent decline in proliferation and regeneration of several peripheral tissue progenitors when compared to wild-type littermates. Aging is the major risk factor for non-inherited forms of Alzheimer's disease (AD); environmental and genetic risk factors that accelerate the senescence phenotype are thought to contribute to an individual's relative risk. In the present study, we evaluated aged DN-p38α(AF/+) and wildtype littermates in a series of behavioral paradigms to test if p38α mutant mice exhibit altered baseline abnormalities in neurological reflexes, locomotion, anxiety-like behavior, and age-dependent cognitive decline. While aged DN-p38α(AF/+) and wildtype littermates appear equal in all tested baseline neurological and behavioral parameters, DN-p38α(AF/+) exhibit superior context discrimination fear conditioning. Context discrimination is a cognitive task that is supported by proliferation and differentiation of adult-born neurons in the dentate gyrus of the hippocampus. Consistent with enhanced context discrimination in aged DN-p38α(AF/+), we discovered enhanced production of adult-born neurons in the dentate gyrus of DN-p38α(AF/+) mice compared to wildtype littermates. Our findings support the notion that p38α inhibition has therapeutic utility in aging diseases that affect cognition, such as AD. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    SciTech Connect

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

    2016-03-18

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

  5. 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

  6. PAK is regulated by PI3K, PIX, CDC42, and PP2Calpha and mediates focal adhesion turnover in the hyperosmotic stress-induced p38 pathway.

    PubMed

    Chan, Perry M; Lim, Louis; Manser, Edward

    2008-09-05

    Fractionation of brain extracts and functional biochemical assays identified PP2Calpha, a serine/threonine phosphatase, as the major biochemical activity inhibiting PAK1. PP2Calpha dephosphorylated PAK1 and p38, both of which were activated upon hyperosmotic shock with the same kinetics. In comparison to growth factors, hyperosmolality was a more potent activator of PAK1. Therefore we characterize the PAK signaling pathway in the hyperosmotic shock response. Endogenous PAKs were recruited to the p38 kinase complex in a phosphorylation-dependent manner. Overexpression of a PAK inhibitory peptide or dominant negative Cdc42 revealed that p38 activation was dependent on PAK and Cdc42 activities. PAK mutants deficient in binding to Cdc42 or PAK-interacting exchange factor were not activated. Using a panel of kinase inhibitors, we identified PI3K acting upstream of PAK, which correlated with PAK repression by pTEN overexpression. RNA interference knockdown of PAK expression reduced stress-induced p38 activation and conversely, PP2Calpha knockdown increased its activation. Hyperosmotic stress-induced PAK translocation away from focal adhesions to the perinuclear compartment and resulted in disassembly of focal adhesions, which are hallmarks of PAK activation. Inhibition of PAK by overexpression of PP2Calpha or the kinase inhibitory domain prevented sorbitol-induced focal adhesion dissolution. Inhibition of MAPK pathways showed that MEK-ERK signaling but not p38 is required for full PAK activation and focal adhesion turnover. We conclude that 1) PAK plays a required role in hyperosmotic signaling through the PI3K/pTEN/Cdc42/PP2Calpha/p38 pathway, and 2) PAK and PP2Calpha modulate the effects of this pathway on focal adhesion dynamics.

  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. 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.

  9. Uric acid stimulates proliferative pathways in vascular smooth muscle cells through the activation of p38 MAPK, p44/42 MAPK and PDGFRβ.

    PubMed

    Kırça, M; Oğuz, N; Çetin, A; Uzuner, F; Yeşilkaya, A

    2017-04-01

    Hyperuricemia and angiotensin II (Ang II) may have a pathogenetic role in the development of hypertension and atherosclerosis as well as cardiovascular disease (CVD) and its prognosis. The purpose of this study was to investigate whether uric acid can induce proliferative pathways of vascular smooth muscle cell (VSMC) that are thought to be responsible for the development of CVD. The phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), p44/42 mitogen-activated protein kinase (p44/42 MAPK) and platelet-derived growth factor receptor β (PDGFRβ) was measured by Elisa and Western blot techniques to determine the activation of proliferative pathways in primary cultured VSMCs from rat aorta. Results demonstrated that uric acid can stimulate p38 MAPK, p44/42 MAPK and PDGFRβ phosphorylation in a time- and concentration-dependent manner. Furthermore, treatment of VSMCs with the angiotensin II type I receptor (AT1R) inhibitor losartan suppressed p38 MAPK and p44/42 MAPK induction by uric acid. The stimulatory effect of uric acid on p38 MAPK was higher compared to that of Ang II. The results of this study show for the first time that uric acid-induced PDGFRβ phosphorylation plays a crucial role in the development of CVDs and that elevated uric acid levels could be a potential therapeutical target in CVD patients.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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 Central

    KIM, GUEN TAE; LEE, SE HEE; KIM, JONG IL; KIM, YOUNG MIN

    2014-01-01

    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. PMID:24535669

  16. 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

  17. In Vivo Identification of Solar Radiation-Responsive Gene Network: Role of the p38 Stress-Dependent Kinase

    PubMed Central

    Mouchet, Nicolas; Adamski, Henri; Bouvet, Régis; Corre, Sébastien; Courbebaisse, Yann; Watier, Eric; Mosser, Jean; Chesné, Christophe; Galibert, Marie-Dominique

    2010-01-01

    Solar radiation is one of the most common threats to the skin, with exposure eliciting a specific protective cellular response. To decrypt the underlying mechanism, we used whole genome microarrays (Agilent 44K) to study epidermis gene expression in vivo in skin exposed to simulated solar radiation (SSR). We procured epidermis samples from healthy Caucasian patients, with phototypes II or III, and used two different SSR doses (2 and 4 J/cm2), the lower of which corresponded to the minimal erythemal dose. Analyses were carried out five hours after irradiation to identify early gene expression events in the photoprotective response. About 1.5% of genes from the human genome showed significant changes in gene expression. The annotations of these affected genes were assessed. They indicated a strengthening of the inflammation process and up-regulation of the JAK-STAT pathway and other pathways. Parallel to the p53 pathway, the p38 stress-responsive pathway was affected, supporting and mediating p53 function. We used an ex vivo assay with a specific inhibitor of p38 (SB203580) to investigate genes the expression of which was associated with active p38 kinase. We identified new direct p38 target genes and further characterized the role of p38. Our findings provide further insight into the physiological response to UV, including cell-cell interactions and cross-talk effects. PMID:20505830

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. Protective Effect of Saccharomyces boulardii on Deoxynivalenol-Induced Injury of Porcine Macrophage via Attenuating p38 MAPK Signal Pathway.

    PubMed

    Chang, Chao; Wang, Kun; Zhou, Sheng-Nan; Wang, Xue-Dong; Wu, Jin-E

    2017-05-01

    The aims of our study were to evaluate the effects of Saccharomyces boulardii (S. boulardii) on deoxynivalenol (DON)-induced injury in porcine alveolar macrophage cells (PAMCs) and to explore the underlying mechanisms. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometric analysis, ELISA, qRT-PCR, and western blot were performed to assess whether S. boulardii could prevent DON-induced injury by p38 mitogen-activated protein kinase (p38 MAPK) signal pathway. The results showed that pretreatment with 8 μM DON could decrease the viability of PAMC and significantly increase the apoptosis rate of PAMC, whereas S. boulardii could rescue apoptotic PAMC cells induced by DON. Further experiments revealed that S. boulardii effectively reversed DON-induced cytotoxicity via downregulating the expression of TNF-α, IL-6, and IL-lβ. In addition, S. boulardii significantly alleviated DON-induced phosphorylation and mRNA expression of p38 and further increased the expression of apoptosis regulation genes Bcl-xl and Bcl-2 and inhibited the activation of Bax. Our results suggest that S. boulardii could suppress DON-induced p38 MAPK pathway activation and reduce the expression of downstream inflammatory cytokines, as well as promote the expression of anti-apoptotic genes to inhibit apoptosis induced by DON in PAMC.

  5. 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.

  6. 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

  7. Effects of portulacerebroside a on apoptosis of human leukemia HL60 cells and p38/JNK signaling pathway

    PubMed Central

    Ye, Qidong; Zhang, Na; Chen, Kai; Zhu, Jiashi; Jiang, Hui

    2015-01-01

    Acute myeloid leukemia is known as one of the most malignant diseases. We aimed at exploring the effect of portulacerebroside A (PCA) on the apoptosis in human leukemia HL60 cells and clarify the possible mechanisms involved in. By MTT analysis, we found that PCA (1-100 μM) inhibited the cell viability in a time- and dose-dependent manner, and cell cycle was arrested at G0/G1 period. PCA treatment from 5 to 50 μM dose-dependently induced apoptosis from 12.7 ± 1.56% to 52.7 ± 6.214% of HL60 cells. Mitochondrial membrane potential (MMP) was decreased and reactive oxygen species (ROS) accumulated obviously. mRNA expressions and protein levels of Bax/Bcl-2, caspase-3 and caspase-9 were elevated significantly. ERK1/2, JNK1/2 and p38 MAPK pathway were blocked detected by western blot analysis. In conclusion, PCA can act as a new agent for leucocythemia treatment. PMID:26823708

  8. 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

  9. 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

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

    PubMed

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

    2016-10-03

    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.

  11. 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

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

    PubMed

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

    2014-03-01

    Light alcohol consumption was reported to be negatively associated with insulin resistance and risk of cardiovascular diseases; however, the results were inconsistent. We here investigate whether long term intake of low-concentration ethanol can affect adiponectin levels. Male Wistar rats were exposed to 0.1% ethanol in drinking water for 26weeks. Visceral adipose tissue (VAT) was cultured and treated with ethanol, SB203580, GW9662, or rosiglitazone. Adiponectin in serum and culture supernatant were measured by ELISA, mRNA levels of adiponectin and PPARγ were determined by RT-PCR, and protein expressions of PPARγ, p38 MAPK and phospho-p38 MAPK were determined by Western blot. In vivo, ethanol decreased the mRNA of adiponectin in VAT and serum adiponectin significantly. Decreased PPARγ and increased activation of p38 MAPK were observed in ethanol treated group. In vitro, SB203580 increased the adiponectin and PPARγ levels in normal DMEM cultured VAT and ameliorated ethanol-induced decrease of adiponectin and PPARγ expressions. GW9662 also decreased the adiponectin levels; Both ethanol and GW9662 weakened the rosiglitazone-induced elevation of adiponectin levels in cultured VAT. These data suggest that long term intake of 0.1% ethanol down-regulated adiponectin levels, and the regulation of PPARγ via p38 MAPK pathway plays an important role in the mechanism underneath. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. 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

  14. Xanthohumol induces paraptosis of leukemia cells through p38 mitogen activated protein kinase signaling pathway

    PubMed Central

    Mi, Xiangquan; Wang, Chunming; Sun, Chao; Chen, Xu; Huo, Xiang; Zhang, Yiming; Li, Gang; Xu, Bo; Zhang, Jun; Xie, Jianxin; Wang, Zhenhua; Li, Ji

    2017-01-01

    Xanthohumol as a natural polyphenol demonstrates an anticancer activity, but its underlying mechanism remains unclear. In this study, we showed that xanthohumol (XN) induces paraptosis of leukemia cells. The paraptosis is one cell death which is characterized by dilation of the endoplasmic reticulum and/or mitochondria. The results demonstrated that XN treatment significantly inhibited cell proliferation and triggered extensive cytoplasmic vacuolation of HL-60 leukemia cells, but it did not cause the cleavage of caspase-3 protein or apoptosis. In contrast, XN treatment resulted in LC3-II accumulation through blocking of autophagosome maturation. Interestingly, the induction of cytoplasmic vacuolization by XN is not associated with autophagy modulated by XN, therefore, XN-induced cell death of HL-60 leukemia cells is not the classical apoptotic cell death. Intriguingly, XN treatment triggered the dilatation of endoplasma reticulum (ER) and induced ER stress by upregulating C/EBP homologous protein and unfolded protein response regulator Grp78/Bip. Furthermore, XN treatment triggered p38 mitogen activated protein kinase and its specific inhibitor inhibited the paraptosis of HL-60 leukemia cells by XN. In conclusion, we for the first time demonstrated that XN treatment can induce paraptosis of leukemia cells through activation of p38 MAPK signaling. PMID:28415750

  15. 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.

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

    PubMed

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

    2015-01-01

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

  17. Electromagnetic-pulse-induced activation of p38 MAPK pathway and disruption of blood-retinal barrier.

    PubMed

    Li, Hai-Juan; Guo, Liang-Mei; Yang, Long-Long; Zhou, Yong-Chun; Zhang, Yan-Jun; Guo, Juan; Xie, Xue-Jun; Guo, Guo-Zhen

    2013-06-20

    The blood-retinal barrier (BRB) is critical for maintaining retina homeostasis and low permeability. In this study, we evaluated the effects of electromagnetic pulse (EMP) exposure on the permeability of BRB, alterations of tight junction (TJ) proteins of BRB and if any, involvement of mitogen-activated protein kinase (MAPK) pathway. Male Sprague-Dawley (SD) rats and RF/6A cells which were pretreated with or without MAPKs inhibitors were sham exposed or exposed to EMP at 200kV/m for 200 pulses. The alteration of BRB permeability was examined through fluorescence microscope and quantitatively assessed using Evans blue (EB) and endogenous albumin as tracers. The expressions of TJ proteins and some signaling molecules of MAPK pathway were measured by Western blots. The observations were that EMP exposure resulted in increased BRB permeability concurrent with the decreased expressions of occludin and claudin-5, which were correlated with the increased expressions of phospho-p38, phospho-JNK and phospho-ERK and could be blocked when pretreated with p38 MAPK inhibitor. Thus, the results suggested that the alterations of occludin and claudin-5 may play an important role in the disruption of TJs, which may lead to the transient breakdown of BRB after EMP exposure with the involvement of p38 MAPK pathway through phosphorylation of signaling molecules. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  18. 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

  19. 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

  20. Maslinic acid induces apoptosis in salivary gland adenoid cystic carcinoma cells by Ca2+-evoked p38 signaling pathway.

    PubMed

    Wu, Dong-Mei; Zhao, Dan; Li, De-Zhi; Xu, Dong-Yang; Chu, Wen-Feng; Wang, Xiao-Feng

    2011-03-01

    Maslinic acid (MA) is a triterpenoid with a high concentration that exists in olives. This natural compound, which has shown multiple biological activities, was proved to be an anti-tumoral agent more recently. We have investigated the mechanisms of MA with regard to its inhibitory effects on the growth of salivary gland adenoid cystic carcinoma (ACC). We demonstrated that MA at 10-100 μM reduced cell viability in a dose-dependent manner, IC(50) of 43.68 μM, and 45.76 μM, respectively in cultured ACC-2 and ACC-M cells. Fifty micromolars of MA efficiently induced apoptosis as indicated by AO/EB staining, electronic microscopy, flow cytometry, and activation of caspase-3 activity. MA induced an elevation of [Ca(2+)](i) in a dose-dependent manner, and cell viability inhibition and cell apoptosis induced by MA were blocked by an intracellular Ca(2+) chelator, BAPTA-AM. The elevation of [Ca(2+)](i) induced by MA was blocked by EGTA or TRPV channel inhibitor suggesting TRPV channel involved in calcium influx induced by MA. MA also activated ERK and p38 MAPK in a time-dependent manner. MA induced cell apoptosis and activation of caspase-3 activity were reversed by SB203580, but not by PD98059, suggesting that the apoptosis induction of MA was via p38 MAPK, but not via ERK. Chelation of intracellular Ca(2+) with BAPTA reversed MA induced p38 MAPK phosphorylation, but SB203580 did not block MA-evoked elevation of [Ca(2+)](i), suggesting a Ca(2+)-evoked p38 MAPK signaling involved in MA-induced apoptosis in ACC cells. Taken together, in ACC cells, maslinic acid induced an increase in [Ca(2+)](i), which evoked p38 MAPK phosphorylation, subsequently activated caspase-3 leading to apoptosis.

  1. 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

  2. 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

  3. Methyl selenium-induced vascular endothelial apoptosis is executed by caspases and principally mediated by p38 MAPK pathway.

    PubMed

    Jiang, Cheng; Kim, Ki-Hwan; Wang, Zaisen; Lü, Junxuan

    2004-01-01

    The induction of vascular endothelial cell apoptosis and inhibition of tumor-associated angiogenesis by selenium may contribute to its cancer chemopreventive effects. Here we examined the stress-activated/mitogen-activated protein kinases (p38 MAPK, ERK1/2) and protein kinase B/AKT as potential signaling mediators for apoptosis induction by a methylselenol precursor methylseleninic acid (MSeA) in human umbilical vein endothelial cells (HUVEC). Time course experiments showed that p38 MAPK hyperphosphorylation and ERK1/2 dephosphorylation occurred before the cleavage of procaspase-3 and poly(ADP-ribose) polymerase (PARP), whereas AKT dephosphorylation occurred after caspase activation. The p38 MAPK inhibitor SB202190 attenuated the MSeA-induced morphological changes and decreased DNA fragmentation and the cleavage of procaspase-3 and PARP in concordant proportions. The general caspase inhibitor zVADfmk completely blocked the MSeA-induced PARP cleavage and DNA fragmentation, whereas zDEVDfmk, an inhibitor for caspase-3-like activities, was nearly as effective for inhibiting apoptosis. In comparison, apoptosis induced by selenite in HUVECs was observed in the complete absence of an activation of the major caspases. Taken together, the data support p38 MAPK as a key upstream mediator for the methylselenol-specific induction of vascular endothelial caspase-dependent apoptosis, which is principally executed by caspase-3-like activities.

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

    PubMed

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

    2016-01-01

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

  5. 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

  6. Helicobacter pylori Induces Serine Phosphorylation of EGFR via Novel TAK1-p38 Activation Pathway in an HB-EGF-Independent Manner.

    PubMed

    Zaidi, Syed Faisal; Refaat, Alaa; Zhou, Yue; Sualeh Muhammad, Jibran; Shin, Myoung-Sook; Saiki, Ikuo; Sakurai, Hiroaki; Sugiyama, Toshiro

    2015-10-01

    The interaction of Helicobacter pylori with gastric epithelial cells can result in the activation of transcription factor NF-κB via TGF-β-activated kinase 1 (TAK1). In this study, we have demonstrated the role of H. pylori in the activation of EGFR via TAK1-mediated phosphorylation of p38. Gastric epithelial AGS or MKN-45 cells were co-cultured with wild-type or cagA(-) H. pylori strains. H. pylori was added to the cells, and the activation of EGFR, p65 (NF-κB) subunit, p38, ERK, and TAK1 was examined by Western blotting. Infected cells were pretreated with or without ligands, chemical inhibitors, anti-HB-EGF antibody, and siRNAs to evaluate the effects on phosphorylation of various EGFR residues. Fluorescence microscopy and flow cytometry were performed to detect the internalization of EGFR. Incubating cells with wild-type and CagA(-) H. pylori strains resulted in the rapid and transient phosphorylation of serine residues of EGFR. RNAi experiments using siRNA against TAK1 and p38 pathways blocked the phosphorylation of serine residue. Immunofluorescence and flow cytometry revealed that EGFR was internalized in H. pylori-infected cells after EGFR phosphorylation in a p38-dependent manner. In contrast, pretreatment with gefitinib and anti-HB-EGF antibody did not block both the phosphorylation and internalization of EGFR. Helicobacter pylori induces internalization of EGFR via novel TAK1-p38-serine activation pathway which is independent of HB-EGF. The interaction between TAK1 and EGFR in H. pylori-infected cells might open new dimensions in understanding H. pylori-associated gastric carcinogenesis. © 2015 John Wiley & Sons Ltd.

  7. 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

  8. Aquaporin 5 expression inhibited by LPS via p38/JNK signaling pathways in SPC-A1 cells.

    PubMed

    Shen, Yao; Chen, Zhihong; Wang, Yuehong; Song, Zhenju; Zhang, Ziqiang; Jin, Meiling; Wang, Xiangdong; Bai, Chunxue

    2010-05-31

    Proper H(2)O to mucin ratio of airway mucus is important for mucociliary clearance. Recent studies suggest that decreased aquaporin 5 (AQP5) is correlated with increased staining of MUC5AC in submucosal glands of COPD patients. Lipopolysaccharide (LPS) is one of the major insults in airway mucin secretion in COPD. In this study, changes in both AQP5 and MUC5AC expression levels in SPC-A1, a human airway submucosal gland cell line, were quantified after exposure of the cells to LPS. AQP5 transcription and protein expression were decreased while MUC5AC expression was increased by LPS exposure in SPC-A1 cells. Further studies revealed that AQP5 expression was down-regulated via the p38/JNK signaling pathway, while MUC5AC was up-regulated through the EGFR-p38/JNK pathway. Therefore, p38 and JNK may become promising targets to preserve AQP5 expression and prevent MUC5AC over-expression to restore proper H(2)O to mucin ratio of the airway mucus, which may be beneficial to the clinical management of COPD patients. Copyright 2010 Elsevier B.V. All rights reserved.

  9. 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.

  10. 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.

  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. The chemokine CCL2 activates p38 mitogen-activated protein kinase pathway in cultured rat hippocampal cells

    PubMed Central

    Cho, Jungsook; Gruol, Donna L.

    2008-01-01

    Emerging evidence indicates that chemokines can regulate both the physiology and biochemistry of CNS neurons and glia. In the current study, Western blot analysis showed that in rat hippocampal neuronal/glial cultures the signal transduction pathway activated by CCL2, a chemokine expressed in the normal brain and at elevated levels during neuroinflammation, involves a G-protein coupled receptor, p38 MAPK as well as its immediate upstream kinase MKK3/6, and the downstream transcription factor CREB. ERK 1/2 and the transcription factors STAT1 and STAT3 do not play a prominent role. CCL2 also altered Ca2+ influx and synaptic network activity in the hippocampal neurons. These results suggest an important role for p38 MAPK and CREB in hippocampal actions of CCL2. PMID:18584881

  13. 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.

  14. 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.

  15. High-magnitude compression accelerates the premature senescence of nucleus pulposus cells via the p38 MAPK-ROS pathway.

    PubMed

    Li, Pei; Hou, Gang; Zhang, Ruijie; Gan, Yibo; Xu, Yuan; Song, Lei; Zhou, Qiang

    2017-09-18

    Mechanical overloading can lead to disc degeneration. Nucleus pulposus (NP) cell senescence is aggravated within the degenerated disc. This study was designed to investigate the effects of high compression on NP cell senescence and the underlying molecular mechanism of this process. Rat NP cells seeded in decalcified bone matrix were subjected to non-compression (control) or compression (2% or 20% deformation, 1.0 Hz, 6 hours/day). The reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) and the p38 MAPK inhibitor SB203580 were used to investigate the roles of the ROS and p38 MAPK pathway under high-magnitude compression. Additionally, we studied the effects of compression (0.1 or 1.3 MPa, 1.0 Hz, 6 hours/day) in a rat disc organ culture. Both in scaffold and organ cultures, high-magnitude compression (20% deformation or 1.3 MPa) increased senescence-associated β-galactosidase (SA-β-Gal) activity, senescence marker (p16 and p53) expression, G1 cell cycle arrest, and ROS generation, and decreased cell proliferation, telomerase activity and matrix (aggrecan and collagen II) synthesis. Further analysis of the 20% deformation group showed that NAC inhibited NP cell senescence but had no obvious effect on phospho-p38 MAPK expression and that SB203580 significantly attenuated ROS generation and NP cell senescence. High-magnitude compression can accelerate NP cell senescence through the p38 MAPK-ROS pathway.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  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. 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.

  2. 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

  3. P-REX1 amplification promotes progression of cutaneous melanoma via the PAK1/P38/MMP-2 pathway.

    PubMed

    Wang, Jinhua; Hirose, Hajime; Du, Guanhua; Chong, Kelly; Kiyohara, Eiji; Witz, Isaac P; Hoon, Dave S B

    2017-10-28

    P-REX1 (PIP3-dependent Rac exchange factor-1) is a guanine nucleotide exchange factor that activates Rac by catalyzing exchange of GDP for GTP bound to Rac. Aberrant up-regulation of P-REX1 expression has a role in metastasis however, copy number (CN) and function of P-REX1 in cutaneous melanoma are unclear. To explore the role of P-REX1 in melanoma, SNP 6.0 and Exon 1.0 ST microarrays were assessed. There was a higher CN (2.82-fold change) of P-REX1 in melanoma cells than in melanocytes, and P-REX1 expression was significantly correlated with P-REX1 CN. When P-REX1 was knocked down in cells by P-REX1 shRNA, proliferation, colony formation, 3D matrigel growth, and migration/invasiveness were inhibited. Loss of P-REX1 inhibited cell proliferation by inhibiting cyclin D1, blocking cell cycle, and increased cell apoptosis by reducing expression of the protein survivin. Knockdown of P-REX1 expression inhibited cell migration/invasiveness by disrupting P-REX1/RAC1/PAK1/p38/MMP-2 pathway. Assessment of patient tumors and disease outcome demonstrated lower distant metastasis-free survival among AJCC stage I/II/III patients with high P-REX1 expression compared to patients with low P-REX1 expression. These results suggest P-REX1 plays an important role in tumor progression and a potential theranostic target. Copyright © 2017. Published by Elsevier B.V.

  4. 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

  5. Recombinant globular adiponectin inhibits lipid deposition by p38 MAPK/ATF-2 and TOR/p70 S6 kinase pathways in chicken adipocytes.

    PubMed

    Jun, Yan; Xiao, Tan; Guoyong, Yan; Min, Feng; Haili, Yang; Chao, Sun

    2014-02-01

    Adiponectin plays a fundamental role in lipid and carbohydrate metabolism. However, its role in adipocyte differentiation remains controversial. To investigate the effect of gAd on lipid deposition in chicken adipocytes and its related signaling pathways, 200 μg/mL recombinant globular adiponectin, isoproterenol, SB253580, leucine, and rapamycin were used to treat chicken adipocytes. Results demonstrated that gAd increased the expression of endogenous adiponectin and AdipoR1 (P < 0.01); gAd inhibited triglyceride (TG) accumulation in chicken adipocyte and increased the release of free fatty acids (FFA) in medium; gAd decreased the expression of adipogenic marker genes CCAAT/enhancer binding protein alpha (C/EBPα) and fatty acid synthase (FAS), while activating the expression of lipolytic marker gene adipose triglyceride lipase (ATGL) (P < 0.01). Meanwhile, gAd activated the phosphorylation levels of p38 mitogen-activated protein kinase (p38 MAPK) and activating transcription factor 2 (ATF-2), and suppressed the phosphorylation levels of rapamycin (TOR) and p70 S6 Kinase (P < 0.01). In conclusion, the results demonstrate that gAd has an ability to inhibit lipids deposition in chicken adipocyte, which depends on the p38 MAPK/ATF-2 and TOR/p70 S6 Kinase pathways.

  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. 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

  8. 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.

  9. 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.

  10. 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.

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

    PubMed Central

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

    2014-01-01

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

  12. 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.

  13. 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.

  14. 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.

  15. Resveratrol induces MMP-9 and cell migration via the p38 kinase and PI-3K pathways in HT1080 human fibrosarcoma cells.

    PubMed

    Gweon, Eun Jeong; Kim, Song Ja

    2013-02-01

    Trans-3,4',5-trihydroxystilbene (resveratrol) is a grape polyphenol present in various plants, food products, red wine and grapes. Resveratrol has anti-inflammatory, anticarcinogenic, anti-oxidant and anti-aging properties. Matrix metalloproteinases (MMPs) are key enzymes involved in the degradation of the extracellular matrix, and their expression may be regulated in cancer metastasis. In the present study, we aimed to evaluate the effect of resveratrol on MMPs and cell migration, and to understand the mechanism of action in HT1080 human fibrosarcoma cells. We found that resveratrol inhibited HT1080 cell viability at various concentrations as detected by the MTT assay and FACS analysis. However, resveratrol dramatically increased the activation and expression of MMP-9 in a dose- and time-dependent manner, as determined by gelatin zymography assay and western blot analysis. We also discovered that resveratrol enhanced the migratory ability of HT1080 cells, as determined by the wound healing assay, and decreased the phosphorylation of p38 kinase. Moreover, the Akt kinase was inhibited by resveratrol in the HT1080 cells. The inhibition of p38 and Akt kinases with SB203580 and LY294002 further increased resveratrol-induced MMP-9 as well as cell migration in the HT1080 cells. Our results suggest that resveratrol regulates MMP-9 and migratory abilities through the p38 kinase and PI-3K pathways in HT1080 human fibrosarcoma cells.

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

    PubMed

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

    2013-03-22

    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. 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. 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.

  19. 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

  20. 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

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

    PubMed

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

    2014-11-01

    Osteoblastic differentiation and bone-forming capacity are known to be suppressed under hypoxic conditions. Melatonin has been shown to influence cell differentiation. A number of in vitro and in vivo studies have suggested that melatonin also has an anabolic effect on bone, by promoting osteoblastic differentiation. However, the precise mechanisms and the signaling pathways involved in this process, particularly under hypoxic conditions, are unknown. This study investigated whether melatonin could promote osteoblastic differentiation and mineralization of preosteoblastic MC3T3-E1 cells under hypoxic conditions. Additionally, we examined the molecular signaling pathways by which melatonin mediates this process. We found that melatonin is capable of promoting differentiation and mineralization of MC3T3-E1 cells cultured under hypoxic conditions. Melatonin upregulated ALP activity and mRNA levels of Alp, Osx, Col1, and Ocn in a time- and concentration-dependent manner. Alizarin red S staining showed that the mineralized matrix in hypoxic MC3T3-E1 cells formed in a manner that was dependent on melatonin concentration. Moreover, melatonin stimulated phosphorylation of p38 Mapk and Prkd1 in these MC3T3-E1 cells. We concluded that melatonin promotes osteoblastic differentiation of MC3T3-E1 cells under hypoxic conditions via the p38 Mapk and Prkd1 signaling pathways. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. 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

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

    PubMed Central

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

    2015-01-01

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

  4. Tricetin inhibits human osteosarcoma cells metastasis by transcriptionally repressing MMP-9 via p38 and Akt pathways.

    PubMed

    Chang, Pin-Yu; Hsieh, Ming-Ju; Hsieh, Yih-Shou; Chen, Pei-Ni; Yang, Jia-Sin; Lo, Fang-Cheng; Yang, Shun-Fa; Lu, Ko-Hsiu

    2017-08-01

    Tricetin, a dietary flavonoid, has cytostatic properties and anti-metastasis activities in various cancer cells. However, the detailed impacts and underlying mechanisms of tricetin on human osteosarcoma cell metastasis are still unclear. Here, the hypothesis that tricetin possesses the anti-metastatic effects on human osteosarcoma cells was tested. The effects of tricetin on cell viability, motility, migration, and invasion in human osteosarcoma U2OS and HOS cells were investigated. Gelatin zymography, western blotting, polymerase chain reaction (PCR), and the luciferase assay were used to further explore the underlying mechanisms involved in anti-metastatic effects in U2OS cells. Their results showed that Tricetin, up to 80 μM without cytotoxicity, attenuated U2OS and HOS cells motility, invasiveness, and migration by reducing matrix metalloproteinase (MMP)-9 enzyme activities. In U2OS cells, tricetin decreased MMP-9 protein and mRNA expressions, which was confirmed by real-time PCR. Next, tricetin reduced phosphorylation of p38 and Akt, but no effect on phosphorylation of ERK1/2 and JNK. In conclusion, tricetin possesses the anti-metastatic activity of osteosarcoma cells by transcriptionally repressing MMP-9 via p38 and Akt signaling pathways. This may be potentially useful as anti-metastatic agents for osteosarcoma chemotherapy. © 2016 Wiley Periodicals, Inc.

  5. CCR2 dependent neutrophil activation and mobilization rely on TLR4-p38 axis during liver ischemia-reperfusion injury

    PubMed Central

    Xu, Peng; Zhang, Junbin; Wang, Hui; Wang, Guoliang; Wang, Cong-Yi; Zhang, Jinxiang

    2017-01-01

    Liver ischemia-reperfusion injury (IRI) is a common clinical problem in which neutrophil recruitment is an essential event. Our previous study revealed the important role of C-C motif chemokine receptor 2 (CCR2) in neutrophils during liver IRI. The aim of the present study was to further investigate the underlying mechanisms mediating the changes in CCR2 expression in neutrophils during this pathophysiological process. Herein, we found that TLR4 ablation reduced neutrophil mobilization from the bone marrow and the subsequent infiltration into the liver during liver IRI; neutrophil-derived CCR2 expression was also repressed. In addition, neutrophil mobilization was dependent on CCR2 expression in neutrophils, which in turn relied on activation of the TLR4-p38 axis during liver IRI. In conclusion, neutrophil-derived CCR2 expression regulates neutrophil mobilization from the bone marrow and infiltration into the liver, which requires activation of the TLR4-p38 axis during liver IRI. PMID:28670376

  6. Calcium ameliorates obesity induced by high-fat diet and its potential correlation with p38 MAPK pathway.

    PubMed

    Sun, Chao; Wang, Li; Yan, Jun; Liu, Shumin

    2012-02-01

    To investigate whether and on which pathway dietary calcium influence the obesity induced by high-fat diet, thirty male Kunming mice were fed in six groups for 4 weeks and mouse preadipocytes were divided into eight groups for different treatment. Body weight gain was measured each week. Calcium in serum and tissues, intracellular free Ca(2+) concentration ([Ca(2+)]i), blood fat and intracellular lipid content were also measured. The expression of Lipid metabolism-related genes were measured by q RT-PCR. Compared with control group, body weight gain (P < 0.05) and fat pad weight (P < 0.01) in Low calcium group decreased. Triglycerides (TG) and total Cholesterol (TC) level decreased (P < 0.01), while HDL-Cholesterol (HDL) level increased (P < 0.01). And calcium supply increased calcium content in blood serum and tissues. In tissues, adipogenesis and vitamin D receptor (VDR) genes expression decreased but lipoclasis genes expression increased. These anti-obesity effects were more obvious when supplying with 2.8% calcium, but the effects were reduced while supplying Nifedipine at the same time. The results in preadipocytes indicated that calcium-treated can reduce intracellular lipid content, along with adipogenesis and lipoclasis genes expression decrease, promoted the expression levels of p38 MAPK pathway upstream gene MKK6 (P < 0.01) and downstream gene MAPKAPK2 (P < 0.01). Treated with SB203580 could increase adipogenesis genes expression, decrease lipoclasis genes expression and ([Ca(2+)]i) (P < 0.01). These results implied that dietary calcium had remarkable effect on anti-obesity effect and p38 MAPK pathway potentially participated in calcium-mediated lipid accumulation and lipolysis in mouse preadipocytes.

  7. 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

  8. 15d-PGJ{sub 2} stimulates HO-1 expression through p38 MAP kinase and Nrf-2 pathway in rat vascular smooth muscle cells

    SciTech Connect

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

    2007-08-15

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

  9. 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.

  10. 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.

  11. Regulation of Sodium Iodide Symporter Gene Expression by Rac1/p38β Mitogen-activated Protein Kinase Signaling Pathway in MCF-7 Breast Cancer Cells*

    PubMed Central

    Kogai, Takahiko; Liu, Yan-Yun; Mody, Kaizeen; Shamsian, Deborah V.; Brent, Gregory A.

    2012-01-01

    Activation of p38 MAPK is a key pathway for cell proliferation and differentiation in breast cancer and thyroid cells. The sodium/iodide symporter (NIS) concentrates iodide in the thyroid and lactating breast. All-trans-retinoic acid (tRA) markedly induces NIS activity in some breast cancer cell lines and promotes uptake of β-emitting radioiodide 131I sufficient for targeted cytotoxicity. To identify a signal transduction pathway that selectively stimulates NIS expression, we investigated regulation by the Rac1-p38 signaling pathway in MCF-7 breast cancer cells and compared it with regulation in FRTL-5 rat thyroid cells. Loss of function experiments with pharmacologic inhibitors and small interfering RNA, as well as RT-PCR analysis of p38 isoforms, demonstrated the requirement of Rac1, MAPK kinase 3B, and p38β for the full expression of NIS in MCF-7 cells. In contrast, p38α was critical for NIS expression in FRTL-5 cells. Treatment with tRA or overexpression of Rac1 induced the phosphorylation of p38 isoforms, including p38β. A dominant negative mutant of Rac1 abolished tRA-induced phosphorylation in MCF-7 cells. Overexpression of p38β or Rac1 significantly enhanced (1.9- and 3.9-fold, respectively), the tRA-stimulated NIS expression in MCF-7 cells. This study demonstrates differential regulation of NIS by distinct p38 isoforms in breast cancer cells and thyroid cells. Targeting isoform-selective activation of p38 may enhance NIS induction, resulting in higher efficacy of 131I concentration and treatment of breast cancer. PMID:22157753

  12. Dietary squalene supplementation improves DSS-induced acute colitis by downregulating p38 MAPK and NFkB signaling pathways.

    PubMed

    Sánchez-Fidalgo, Susana; Villegas, Isabel; Rosillo, Maria Ángeles; Aparicio-Soto, Marina; de la Lastra, Catalina Alarcón

    2015-02-01

    Squalene is a polyunsaturated triterpene, which has exhibited anticancer and antioxidant activities among others. We investigated dietary squalene supplementation effect on an acute colitis model induced by dextran sulfate sodium (DSS) in C57BL/6 mice. Mice were fed from weaning with squalene at 0.02% and 0.1%. After 4 weeks, mice were exposed to 3% DSS for 5 days developing acute colitis. After DSS removal (5 days), colons were histological and biochemically processed. Our results showed that dietary squalene treatment exerts anti-inflammatory action in DSS-induced acute colitis. Western blot revealed that squalene downregulated COX-2 (where COX is cyclooxygenase) and inducible nitric oxide synthase system by inhibition of mitogen-activated protein kinase p38 and the nuclear factor-kappa B signaling pathways, preventing an increase in the cytokines levels. Under our experimental conditions, STAT3 and FOXP3 (where FOXP3 is forkhead box P3) were not modified and the transcriptional regulation of antioxidant and/or detoxifying enzymes, Nrf2 (where Nrf2 is nuclear factor (erythroid-derived 2)-like 2), was reduced in DSS-induced colitis. However, any change could be observed after squalene supplementation. Squalene was able to improve the oxidative events and returned proinflammatory proteins expression to basal levels probably through p38 mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways. However, supplementary studies are needed in order to provide a basis for developing a new dietary supplementation strategy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. [Effect of supplementing Qi-nourishing Yin-dispersing blood stasis-dredging collateral herbs on p38 MAPK signaling pathway in kidney of early diabetic rats].

    PubMed

    Zhao, Wenhong; Chen, Zhiqiang; Zhang, Jianghua; Sun, Yufeng; Wang, Yuehua; Wang, Huiqing

    2010-03-01

    To study the effect of supplementing Qi-nourishing Yin and dispersing blood stasis-dredging collateral herbs on p38 mitogen activated protein kinase (p38 MAPK) signaling pathway in the kidney of early diabetic rats. Dividing SD rats randomly into 6 groups: Simple nephrectomy group, model group, irbesatan group, traditional Chinese medicine (TCM) low dose group, TCM middle dose group and TCM high dose group. Each group of rats was fed with the corresponding dose of medicine. After 6 weeks, detecting 24 h urine protein (UPro) level, renal function, p38 MAPK mRNA and p-p38 MAPK protein level. UPro levels of irbesatan group, TCM low group and TCM middle dose group decreased significantly (P < 0.05) , compared with that of the model group. Renal function of the treated groups was improved greatly and their p38 MAPK mRNA and p-p38MAPK protein levels decreased significantly (P < 0.05), compared with those of the model group. Supplementing Qi-nourishing Yin-dispersing blood stasis-dredging collateral herbs could treat DN rats effectively by inhibiting the expression of p38 MAPK signaling pathway.

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

    PubMed

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

    2016-04-01

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

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

    PubMed Central

    2011-01-01

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

  2. 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

  3. 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

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

    PubMed

    Huxtable, Adrianne G; Smith, Stephanie M C; Peterson, Timothy J; Watters, Jyoti J; Mitchell, Gordon S

    2015-04-29

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

  5. 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.

  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. 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.

  8. 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

  9. 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.

  10. Adiponectin attenuates high glucose-induced apoptosis through the AMPK/p38 MAPK signaling pathway in NRK-52E cells

    PubMed Central

    Wang, Yuanyuan; Zhang, Juan; Zhang, Lian; Gao, Ping

    2017-01-01

    Excessive apoptosis of proximal tubule cell is closely related to the development of diabetes. Recent evidence suggests that adiponectin (ADPN) protects cells from high glucose induced apoptosis. However, the precise mechanisms remain poorly understood. We sought to investigate the role of p38 mitogen-activated protein kinase (p38 MAPK) and AMP activated protein kinase (AMPK) in anti-apoptotic of adiponectin under high glucose condition in rat tubular NRK-52E cells. Cells were cultured in constant and oscillating high glucose media with or without recombinant rat adiponectin for 48 h. Cell counting kit-8 (CCK-8) was used to detect cell viability, flow cytometry and Hoechst Staining were applied to investigate cell apoptosis, and western blotting was used to examine protein expression, such as phospho-AMPK and phospho-p38MAPK. Exposure to oscillating high glucose exerted lower cell viability and higher early apoptosis than constant high glucose, which were both partially prevented by adiponectin. Further studies revealed that adiponectin suppressed p38MAPK phosphorylation, but led to an increase in AMPK α phosphorylation. Compared to stable high glucose group, blockage of p38MAPK cascade with SB203580 attenuated apoptosis significantly, but failed to affect the phosphorylation level of AMPK. While AMPK inhibitor, Compound C, increased apoptosis and remarkably inhibited the p38MAPK phosphorylation. Adiponectin exert a crucial protective role against apoptosis induced by high glucose via AMPK/p38MAPK pathway. PMID:28542560

  11. Adiponectin attenuates high glucose-induced apoptosis through the AMPK/p38 MAPK signaling pathway in NRK-52E cells.

    PubMed

    Wang, Yuanyuan; Zhang, Juan; Zhang, Lian; Gao, Ping; Wu, Xiaoyan

    2017-01-01

    Excessive apoptosis of proximal tubule cell is closely related to the development of diabetes. Recent evidence suggests that adiponectin (ADPN) protects cells from high glucose induced apoptosis. However, the precise mechanisms remain poorly understood. We sought to investigate the role of p38 mitogen-activated protein kinase (p38 MAPK) and AMP activated protein kinase (AMPK) in anti-apoptotic of adiponectin under high glucose condition in rat tubular NRK-52E cells. Cells were cultured in constant and oscillating high glucose media with or without recombinant rat adiponectin for 48 h. Cell counting kit-8 (CCK-8) was used to detect cell viability, flow cytometry and Hoechst Staining were applied to investigate cell apoptosis, and western blotting was used to examine protein expression, such as phospho-AMPK and phospho-p38MAPK. Exposure to oscillating high glucose exerted lower cell viability and higher early apoptosis than constant high glucose, which were both partially prevented by adiponectin. Further studies revealed that adiponectin suppressed p38MAPK phosphorylation, but led to an increase in AMPK α phosphorylation. Compared to stable high glucose group, blockage of p38MAPK cascade with SB203580 attenuated apoptosis significantly, but failed to affect the phosphorylation level of AMPK. While AMPK inhibitor, Compound C, increased apoptosis and remarkably inhibited the p38MAPK phosphorylation. Adiponectin exert a crucial protective role against apoptosis induced by high glucose via AMPK/p38MAPK pathway.

  12. 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

  13. 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.

  14. 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

  15. Transcription of the Transforming Growth Factor β Activating Integrin β8 Subunit Is Regulated by SP3, AP-1, and the p38 Pathway*

    PubMed Central

    Markovics, Jennifer A.; Araya, Jun; Cambier, Stephanie; Jablons, David; Hill, Arthur; Wolters, Paul J.; Nishimura, Stephen L.

    2010-01-01

    Integrin αvβ8 is a critical regulator of transforming growth factor β activation in vasculogenesis during development, immune regulation, and endothelial/epithelial-mesenchymal homeostasis. Recent studies have suggested roles for integrin β8 in the pathogenesis of chronic obstructive pulmonary disease, brain arteriovenous malformations, and select cancers (Araya, J., Cambier, S., Markovics, J. A., Wolters, P., Jablons, D., Hill, A., Finkbeiner, W., Jones, K., Broaddus, V. C., Sheppard, D., Barzcak, A., Xiao, Y., Erle, D. J., and Nishimura, S. L. (2007) J. Clin. Invest. 117, 3551–3562; Su, H., Kim, H., Pawlikowska, L., Kitamura, H., Shen, F., Cambier, S., Markovics, J., Lawton, M. T., Sidney, S., Bollen, A. W., Kwok, P. Y., Reichardt, L., Young, W. L., Yang, G. Y., and Nishimura, S. L. (2010) Am. J. Pathol. 176, 1018–1027; Culhane, A. C., and Quackenbush, J. (2009) Cancer Res. 69, 7480–7485; Cambier, S., Mu, D. Z., O'Connell, D., Boylen, K., Travis, W., Liu, W. H., Broaddus, V. C., and Nishimura, S. L. (2000) Cancer Res. 60, 7084–7093). Here we report the first identification and characterization of the promoter for ITGB8. We show that a SP binding site and a cyclic AMP response element (CRE) in the ITGB8 core promoter are required for its expression and that Sp1, Sp3, and several AP-1 transcription factors form a complex that binds to these sites in a p38-dependent manner. Furthermore, we demonstrate the requirement for Sp3, ATF-2, and p38 for the transcription and protein expression of integrin β8. Additionally, reduction of SP3 or inhibition of p38 blocks αvβ8-mediated transforming growth factor β activation. These results place integrin β8 expression and activity under the control of ubiquitous transcription factors in a stress-activated and pro-inflammatory pathway. PMID:20519498

  16. Lipopolysaccharide-enhanced transcellular transport of HIV-1 across the blood-brain barrier is mediated by the p38 mitogen-activated protein kinase pathway

    PubMed Central

    Dohgu, Shinya; Banks, William A.

    2008-01-01

    Chronic systemic inflammation in the late stage of human immunodeficiency virus type-1 (HIV-1) infection could increase neuroinvasion of infected monocytes and cell-free virus, causing an aggravation of neurological disorders in AIDS patients. We previously showed that the peripheral administration of lipopolysaccharide (LPS) enhanced the uptake across the blood-brain barrier (BBB) of the HIV-1 viral protein gp120. Brain microvessel endothelial cells are targets of LPS. Here, we investigated whether the direct interaction between LPS and the BBB also affected HIV-1 transport using primary mouse brain microvessel endothelial cells (BMECs). LPS produced a dose (1–100 μg/mL)- and time (0.5–4 hr)-dependent increase in HIV-1 transport and a decrease in transendothelial electrical resistance (TEER). Whereas indomethacin (cyclooxygenase inhibitor) and L-NAME (NO synthase inhibitor) did not affect the LPS-induced changes in HIV-1 transport or TEER, pentoxifylline (TNF-αinhibitor) attenuated the decrease in TEER induced by LPS, but not the LPS-induced increase in HIV-1 transport. LPS also increased the phosphorylation of p44/42 MAPK and p38 MAPK but not that of JNK. U0126 (p44/42 MAPK inhibitor) and SP600125 (JNK inhibitor) did not inhibit the LPS-induced increase in HIV-1 transport although U0126 attenuated the reduction in TEER. SB203580 (p38 MAPK inhibitor) inhibited the LPS-induced increase in HIV-1 transport without affecting TEER. Thus, LPS-enhanced HIV-1 transport is independent of changes in TEER and so is attributed to increased transcellular trafficking of HIV-1 across the BBB. These results show that LPS increases HIV-1 transcellular transport across the BBB by a pathway that is mediated by p38 MAPK phosphorylation in BMECs. PMID:18295207

  17. 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

  18. Hyperoside inhibits lipopolysaccharide-induced inflammatory responses in microglial cells via p38 and NFκB pathways.

    PubMed

    Fan, Hui-Hui; Zhu, Lan-Bing; Li, Ting; Zhu, Hui; Wang, Ya-Nan; Ren, Xiao-Li; Hu, Bei-Lei; Huang, Chen-Ping; Zhu, Jian-Hong; Zhang, Xiong

    2017-09-01

    Hyperoside (quercetin-3-O-β-d-galactoside) is an active compound isolated from herbs. Neuroinflammation is a key mechanism involved in neurodegenerative disorders including Parkinson's disease. In this study, we aimed to investigate the potentiality of hyperoside in inhibiting microglia-mediated neuroinflammation. BV2 microglial cells were pretreated with hyperoside and stimulated with lipopolysaccharide (LPS). The results showed that hyperoside significantly inhibited LPS-induced production of nitric oxide and pro-inflammatory cytokines including IL-1β and TNF-α, as well as the expression of inducible nitric oxide synthase. Similar results were observed in primary microglial cells isolated from neonatal mice. Analyses in MAPK and NFκB signaling combined with specific inhibitors suggested that hyperoside attenuated the LPS-induced inflammatory responses via p38 and NFκB pathways. Furthermore, hyperoside suppressed reactive microglia-mediated neurotoxicity as evidenced by conditioned media culture, but had no direct impact on MPP(+)-induced toxicity in SH-SY5Y neuroblastoma cells. Collectively, our data suggest that hyperoside may serve as a protective agent by alleviating microglia activation in disorders such as Parkinson's disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. 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.

  20. Heat shock induces neurite outgrowth in PC12m3 cells via the p38 mitogen-activated protein kinase pathway.

    PubMed

    Kano, Yoshio; Nakagiri, Sachiko; Nohno, Tsutomu; Hiragami, Fukumi; Kawamura, Kenji; Kadota, Michiyo; Numata, Keizo; Koike, Yoshihisa; Furuta, Tomohisa

    2004-11-12

    We investigated the role of the p38 mitogen-activated protein kinase (MAPK) pathway in heat-shock-induced neurite outgrowth of PC12 mutant cells in which nerve growth factor (NGF)-induced neurite outgrowth is impaired. When cultures of the PC12 mutant (PC12m3) cells were exposed to heat stress at 44 degrees C for 10 min, activity of p38 MAPK increased and neurite outgrowth was greatly enhanced. The neurite extension was inhibited by the p38 MAPK inhibitor BS203580. Longer heat treatment of PC12m3 cells provoked cell death, which was enhanced by SB203580. These findings suggest that heat-induced activation of p38 MAPK is responsible for the neurite outgrowth and survival of PC12m3 cells.

  1. Activation of p38 MAPK pathway in the skull abnormalities of Apert syndrome Fgfr2+P253R mice

    PubMed Central

    2010-01-01

    Background Apert syndrome is characterized by craniosynostosis and limb abnormalities and is primarily caused by FGFR2 +/P253R and +/S252W mutations. The former mutation is present in approximately one third whereas the latter mutation is present in two-thirds of the patients with this condition. We previously reported an inbred transgenic mouse model with the Fgfr2 +/S252W mutation on the C57BL/6J background for Apert syndrome. Here we present a mouse model for the Fgfr2+/P253R mutation. Results We generated inbred Fgfr2+/P253R mice on the same C56BL/6J genetic background and analyzed their skeletal abnormalities. 3D micro-CT scans of the skulls of the Fgfr2+/P253R mice revealed that the skull length was shortened with the length of the anterior cranial base significantly shorter than that of the Fgfr2+/S252W mice at P0. The Fgfr2+/P253R mice presented with synostosis of the coronal suture and proximate fronts with disorganized cellularity in sagittal and lambdoid sutures. Abnormal osteogenesis and proliferation were observed at the developing coronal suture and long bones of the Fgfr2+/P253R mice as in the Fgfr2+/S252W mice. Activation of mitogen-activated protein kinases (MAPK) was observed in the Fgfr2+/P253R neurocranium with an increase in phosphorylated p38 as well as ERK1/2, whereas phosphorylated AKT and PKCα were not obviously changed as compared to those of wild-type controls. There were localized phenotypic and molecular variations among individual embryos with different mutations and among those with the same mutation. Conclusions Our in vivo studies demonstrated that the Fgfr2 +/P253R mutation resulted in mice with cranial features that resemble those of the Fgfr2+/S252W mice and human Apert syndrome. Activated p38 in addition to the ERK1/2 signaling pathways may mediate the mutant neurocranial phenotype. Though Apert syndrome is traditionally thought to be a consistent phenotype, our results suggest localized and regional variations in the

  2. 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

  3. Anti-Inflammatory Effects of Secondary Metabolites of Marine Pseudomonas sp. in Human Neutrophils Are through Inhibiting P38 MAPK, JNK, and Calcium Pathways

    PubMed Central

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

    2014-01-01

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

  4. 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

  5. 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.

  6. 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.

  7. IL-1β-induced and p38(MAPK)-dependent activation of the mitogen-activated protein kinase-activated protein kinase 2 (MK2) in hepatocytes: Signal transduction with robust and concentration-independent signal amplification.

    PubMed

    Kulawik, Andreas; Engesser, Raphael; Ehlting, Christian; Raue, Andreas; Albrecht, Ute; Hahn, Bettina; Lehmann, Wolf-Dieter; Gaestel, Matthias; Klingmüller, Ursula; Häussinger, Dieter; Timmer, Jens; Bode, Johannes G

    2017-04-14

    The IL-1β induced activation of the p38(MAPK)/MAPK-activated protein kinase 2 (MK2) pathway in hepatocytes is important for control of the acute phase response and regulation of liver regeneration. Many aspects of the regulatory relevance of this pathway have been investigated in immune cells in the context of inflammation. However, very little is known about concentration-dependent activation kinetics and signal propagation in hepatocytes and the role of MK2. We established a mathematical model for IL-1β-induced activation of the p38(MAPK)/MK2 pathway in hepatocytes that was calibrated to quantitative data on time- and IL-1β concentration-dependent phosphorylation of p38(MAPK) and MK2 in primary mouse hepatocytes. This analysis showed that, in hepatocytes, signal transduction from IL-1β via p38(MAPK) to MK2 is characterized by strong signal amplification. Quantification of p38(MAPK) and MK2 revealed that, in hepatocytes, at maximum, 11.3% of p38(MAPK) molecules and 36.5% of MK2 molecules are activated in response to IL-1β. The mathematical model was experimentally validated by employing phosphatase inhibitors and the p38(MAPK) inhibitor SB203580. Model simulations predicted an IC50 of 1-1.2 μm for SB203580 in hepatocytes. In silico analyses and experimental validation demonstrated that the kinase activity of p38(MAPK) determines signal amplitude, whereas phosphatase activity affects both signal amplitude and duration. p38(MAPK) and MK2 concentrations and responsiveness toward IL-1β were quantitatively compared between hepatocytes and macrophages. In macrophages, the absolute p38(MAPK) and MK2 concentration was significantly higher. Finally, in line with experimental observations, the mathematical model predicted a significantly higher half-maximal effective concentration for IL-1β-induced pathway activation in macrophages compared with hepatocytes, underscoring the importance of cell type-specific differences in pathway regulation. © 2017 by The American

  8. 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

  9. Diallyl disulfide-induced G2/M arrest of human gastric cancer MGC803 cells involves activation of p38 MAP kinase pathways

    PubMed Central

    Yuan, Jing-Ping; Wang, Gui-Hua; Ling, Hui; Su, Qi; Yang, Yue-Hong; Song, Ying; Tang, Rong-Jun; Liu, Yao; Huang, Chen

    2004-01-01

    AIM: To determine the role of p38 MAP kinase signal transduction pathways in diallyl disulfide (DADS)-induced G2/M arrest in human gastric cancer MGC803 cells. METHODS: MGC803 cell growth inhibition was measured by MTT assay. Phase distribution of cell cycle was analyzed by flow cytometry. Expression of Cdc25C, p38, phosphorylation of p38 (pp38) were determined by Western blotting. RESULTS: MTT assay showed that SB203580, a specific p38 MAPK inhibitor blocked DADS-induced growth inhibition. Flow cytometry analysis revealed that treatment of MGC803 cells with 30 mg/L DADS increased the percentage of cells in the G2/M phase from 9.3% to 39.4% (P < 0.05), whereas inhibition of p38 activity by SB203580 abolished induction of G2/M arrest by DADS. Western blotting showed that phosphorylation of p38 was increased 3.52-fold following treatment of MGC803 cells with 30 mg/L DADS for 20 min (P < 0.05), whereas Cdc25C was decreased 68% following treatment of MGC803 cells with 30 mg/L DADS for 24 h (P < 0.05). Decreased Cdc25C protein expression by DADS was attenuated by SB203580 (P < 0.05). CONCLUSION: DADS-induced G2/M arrest of MGC803 cells involves activation of p38 MAP kinase pathways. Decreased Cdc25C protein expression by p38 MAPK played a crucial role in G2/M arrest after treatment with DADS. PMID:15309729

  10. 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.

  11. Notexin upregulates Fas and FasL protein expression of human neuroblastoma SK-N-SH cells through p38 MAPK/ATF-2 and JNK/c-Jun pathways.

    PubMed

    Chen, Ku-Chung; Chang, Long-Sen

    2010-04-01

    Notechis scutatus scutatus notexin induced an increase in Fas and FasL protein expression of human neuroblastoma SK-N-SH cells in a dose- and time-dependent manner. Moreover, notexin treatment upregulated transcription of Fas/FasL mRNA. Downregulation of FADD blocked notexin-induced procaspase-8 degradation and cleavage of Bid and rescued viability of notexin-treated cells. Upon exposure to notexin, activation of JNK and p38 MAPK was observed in SK-N-SH cells. Notexin-induced upregulation of Fas and FasL was suppressed by SB202190 (p38 MAPK inhibitor) and S600125 (JNK inhibitor). Downregulation of p38alpha MAPK and JNK1 by siRNA proved that upregulation of Fas/FasL was related to p38alpha MAPK and JNK1 activation. Notexin treatment evoked p38alpha MAPK-mediated ATF-2 phosphorylation and JNK1-mediated c-Jun phosphorylation. Knockdown of c-Jun and ATF-2 by siRNA or overexpression of dominant-negative c-Jun and ATF-2 revealed that both c-Jun and ATF-2 were crucial for Fas/FasL upregulation. Taken together, our data indicate that notexin-induced upregulation of Fas and FasL is triggered by p38 MAPK/ATF-2 and JNK/c-Jun signaling pathways in SK-N-SH cells. Copyright 2009 Elsevier Ltd. All rights reserved.

  12. 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

  13. C/EBPβ Mediates TNF-α-Induced Cancer Cell Migration by Inducing MMP Expression Dependent on p38 MAPK.

    PubMed

    Xia, Peiyi; Zhang, Rui; Ge, Gaoxiang

    2015-12-01

    Tumor necrosis factor (TNF)-α is a pleiotropic cytokine that triggers cell proliferation, cell death, or inflammation. Besides its cytotoxic effect on cancer cells, TNF-α exerts tumor promoting activity. Aberrant TNF-α signaling promotes cancer cell motility, invasiveness, and enhances cancer metastasis. Exaggerated tumor cell migration, invasion, and metastasis by TNF-α has been attributed to the activation of NF-κB signaling. It is yet to be elucidated if other signaling pathways and effector molecules are involved in TNF-α-induced cancer cell migration and metastasis. Expression of C/EBPβ, a transcription factor involved in metabolism, inflammation, and cancer, is increased upon TNF-α treatment. TNF-α induces C/EBPβ expression by enhancing its transcription and protein stability. Activation of p38 MAPK, but not NF-κB or JNK, is responsible for TNF-α-induced stabilization of C/EBPβ protein. C/EBPβ is involved in TNF-α-induced cancer cell migration. Knockdown of C/EBPβ inhibits TNF-α-induced cell migration, while overexpression of C/EBPβ increases migration of cancer cells. C/EBPβ is translated into transcriptional activator LAP1 and LAP2 and transcriptional repressor LIP utilizing alternative in-frame translation start sites. Despite TNF-α induces expression of all three isoforms, LAP1/2, but not LIP, promote cancer cell migration. TNF-α induced MMP1/3 expression, which was abrogated by C/EBPβ knockdown or p38 MAPK inhibition. MMP inhibitor or knockdown of MMP1/3 diminished TNF-α- and C/EBPβ-induced cell migration. Thus, C/EBPβ mediates TNF-α-induced cancer cell migration by inducing MMP1/3 expression, and may participate in the regulation of inflammation-associated cancer metastasis. © 2015 Wiley Periodicals, Inc.

  14. Nonthermal plasma induces apoptosis in ATC cells: involvement of JNK and p38 MAPK-dependent ROS.

    PubMed

    Lee, Sei Young; Kang, Sung Un; Kim, Kang Il; Kang, Sam; Shin, Yoo Seob; Chang, Jae Won; Yang, Sang Sik; Lee, Keunho; Lee, Jong-Soo; Moon, Eunpyo; Kim, Chul-Ho

    2014-11-01

    To determine the effects of nonthermal plasma (NTP) induced by helium (He) alone or He plus oxygen (O₂) on the generation of reactive oxygen species (ROS) and cell death in anaplastic thyroid cancer cells. NTP was generated in He alone or He plus O₂ blowing through a nozzle by applying a high alternating current voltage to the discharge electrodes. Optical emission spectroscopy was used to identify various excited plasma species. The apoptotic effect of NTP on the anaplastic thyroid cancer cell lines, such as HTH83, U-HTH 7, and SW1763, was verified with annexin V/propidium staining and TUNEL assay. ROS formation after NTP treatment was identified with fluorescence-activated cell sorting with DCFDA staining. The mitogen-activated protein kinase pathways and caspase cascade were investigated to evaluate the molecular mechanism involved and cellular targets of plasma. NTP induced significant apoptosis in all three cancer cell lines. The plasma using He and O₂ generated more O₂-related species, and increased apoptosis and intracellular ROS formation compared with the plasma using He alone. NTP treatment of SW1763 increased the expression of phosphor-JNK, phosphor-p38, and caspase-3, but not phosphor-ERK. Apoptosis of SW1763 as well as expressions of elevated phosphor-JNK, phosphor-p38, and caspase-3 induced by NTP were effectively inhibited by intracellular ROS scavengers. NTP using He plus O₂ induced significant apoptosis in anaplastic cancer cell lines through intracellular ROS formation. This may represent a new promising treatment modality for this highly lethal disease.

  15. Activation of cannabinoid receptor 2 reduces inflammation in acute experimental pancreatitis via intra-acinar activation of p38 and MK2-dependent mechanisms.

    PubMed

    Michler, Thomas; Storr, Martin; Kramer, Johannes; Ochs, Stefanie; Malo, Antje; Reu, Simone; Göke, Burkhard; Schäfer, Claus

    2013-01-15

    The endocannabinoid system has been shown to mediate beneficial effects on gastrointestinal inflammation via cannabinoid receptors 1 (CB(1)) and 2 (CB(2)). These receptors have also been reported to activate the MAP kinases p38 and c-Jun NH(2)-terminal kinase (JNK), which are involved in early acinar events leading to acute pancreatitis and induction of proinflammatory cytokines. Our aim was to examine the role of cannabinoid receptor activation in an experimental model of acute pancreatitis and the potential involvement of MAP kinases. Cerulein pancreatitis was induced in wild-type, CB(1)-/-, and MK2-/- mice pretreated with selective cannabinoid receptor agonists or antagonists. Severity of pancreatitis was determined by serum amylase and IL-6 levels, intracellular activation of pancreatic trypsinogen, lung myeloperoxidase activity, pancreatic edema, and histological examinations. Pancreatic lysates were investigated by Western blotting using phospho-specific antibodies against p38 and JNK. Quantitative PCR data, Western blotting experiments, and immunohistochemistry clearly show that CB(1) and CB(2) are expressed in mouse pancreatic acini. During acute pancreatitis, an upregulation especially of CB(2) on apoptotic cells occurred. The unselective CB(1)/CB(2) agonist HU210 ameliorated pancreatitis in wild-type and CB(1)-/- mice, indicating that this effect is mediated by CB(2). Furthermore, blockade of CB(2), not CB(1), with selective antagonists engraved pathology. Stimulation with a selective CB(2) agonist attenuated acute pancreatitis and an increased activation of p38 was observed in the acini. With use of MK2-/- mice, it could be demonstrated that this attenuation is dependent on MK2. Hence, using the MK2-/- mouse model we reveal a novel CB(2)-activated and MAP kinase-dependent pathway that modulates cytokine expression and reduces pancreatic injury and affiliated complications.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

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

    PubMed

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

    2010-09-01

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

  2. 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

  3. 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

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

    PubMed

    Jiang, Kang-Feng; Zhao, Gan; Deng, Gan-Zhen; Wu, Hai-Chong; Yin, Nan-Nan; Chen, Xiu-Ying; Qiu, Chang-Wei; Peng, Xiu-Li

    2017-02-01

    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.

  5. 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.

  6. 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

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

    PubMed

    Yu, Seon-Mi; Kim, Song Ja

    2016-06-01

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

  8. 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. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  9. 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

  10. Immunomodulatory effects of Lippia sidoides extract: induction of IL-10 through cAMP and p38 MAPK-dependent mechanisms.

    PubMed

    Rajgopal, Arun; Rebhun, John F; Burns, Charlie R; Scholten, Jeffrey D; Balles, John A; Fast, David J

    2015-03-01

    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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. Induction of interleukin-8 secretion and activation of ERK1/2, p38 MAPK signaling pathways by thrombin in dermal fibroblasts.

    PubMed

    Wang, Li; Luo, Jianmin; Fu, Yiling; He, Shaoheng

    2006-01-01

    It was reported that thrombin could induce IL-8 secretion from human dermal fibroblasts (HDFs) through activation of proteinase activated receptor (PAR)-1. However, little is known of intracellular signaling pathways involved in the event. In the present study, expression of PARs in primarily cultured HDFs was determined by flow cytometry analysis and reverse transcription polymerase chain reaction (RT-PCR), levels of IL-8 were determined by using ELISA and signaling pathways were examined by using Western blot. It was found that HDFs express PAR-1 and PAR-3, and thrombin induces approximately 7.4-fold increase in IL-8 secretion from HDFs. Hirudin and a PAR-1 blocking antibody completely abolish the action of thrombin. It was also found that PD98059, a mitogen-activated protein kinase (MAPK) pathway inhibitor and U0126, an inhibitor of extracellular signal-regulated kinase (ERK) blocks thrombin-induced phosphorylation of ERK1/2 and IL-8 secretion, indicating the involvement of MAPK/ERK signaling pathway in thrombin-induced IL-8 secretion. p38 MAPK pathway appears also being involved as SB203580, a selective inhibitor of p38 MAPK inhibit phosphorylation of p38 MAPK and thrombin-induced IL-8 secretion. Furthermore, Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathway, but not phosphotidylinositol 3-kinase (PI3K)/Akt signaling pathway may also be activated by thrombin. In conclusion, thrombin potently induce IL-8 release via PAR-1 from HDFs. Thrombin elicited IL-8 release is predominantly conducted through MAPK/ERK and p38 MAPK signaling pathways. Discovery of the signaling pathways of thrombin in HDFs may help to understand the role of thrombin in inflammation and tissue remodeling.

  18. Lipopolysaccharide decreases single immunoglobulin interleukin-1 receptor-related molecule (SIGIRR) expression by suppressing specificity protein 1 (Sp1) via the Toll-like receptor 4 (TLR4)-p38 pathway in monocytes and neutrophils.

    PubMed

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

    2014-06-27

    Single immunoglobulin interleukin-1 receptor-related molecule (SIGIRR) is one of the immunoglobulin-like membrane proteins that is crucial for negative regulation of toll-like receptor 4 (TLR4) and interleukin-1 receptor. Despite the importance of understanding its expression and function, knowledge is limited on the regulatory mechanism in the epithelial tissues, such as the liver, lung, and gut, where its predominant expression is originally described. Here, we found expression of SIGIRR in non-epithelial innate immune cells, including primary peripheral blood monocytes, polymorphonuclear neutrophils, monocytic RAW264 cells, and neutrophilic-differentiated HL-60 cells. Consistent with previous findings in epithelial tissues, SIGIRR gene and protein expression were also down-regulated by LPS treatment in a time-dependent manner in primary blood monocytes and polymorphonuclear neutrophils. A reduction was also observed in RAW264 and differentiated HL-60 cells. Notably, exogenous introduction of the dominant negative form of TLR4 and siRNA of p38 resulted in inhibition of LPS-induced SIGIRR down-regulation, whereas treatment with p38 activator anisomycin showed a dose-dependent decrease in SIGIRR expression, suggesting TLR4-p38 signal as a critical pathway for LPS-induced SIGIRR down-regulation. Finally, reporter gene and chromatin immunoprecipitation assays demonstrated that Sp1 is a key factor that directly binds to the proximal promoter of SIGIRR gene and consequently regulates basal SIGIRR expression, which is negatively regulated by the LPS-dependent TLR4-p38 pathway. In summary, the data precisely demonstrate how LPS down-regulates SIGIRR expression and provide a role of LPS signal that counteracts Sp1-dependent basal promoter activation of SIGIRR gene via TLR4-p38 pathway in non-epithelial innate immune cells. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    PubMed Central

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

    2014-01-01

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

  20. A Drosophila model of myeloproliferative neoplasm reveals a feed-forward loop in the JAK pathway mediated by p38 MAPK signalling

    PubMed Central

    Pérez, Lidia; Bray, Sarah J.

    2017-01-01

    ABSTRACT Myeloproliferative neoplasms (MPNs) of the Philadelphia-negative class comprise polycythaemia vera, essential thrombocythaemia and primary myelofibrosis (PMF). They are associated with aberrant numbers of myeloid lineage cells in the blood, and in the case of overt PMF, with development of myelofibrosis in the bone marrow and failure to produce normal blood cells. These diseases are usually caused by gain-of-function mutations in the kinase JAK2. Here, we use Drosophila to investigate the consequences of activation of the JAK2 orthologue in haematopoiesis. We have identified maturing haemocytes in the lymph gland, the major haematopoietic organ in the fly, as the cell population susceptible to induce hypertrophy upon targeted overexpression of JAK. We show that JAK activates a feed-forward loop, including the cytokine-like ligand Upd3 and its receptor, Domeless, which are required to induce lymph gland hypertrophy. Moreover, we present evidence that p38 MAPK signalling plays a key role in this process by inducing expression of the ligand Upd3. Interestingly, we also show that forced activation of the p38 MAPK pathway in maturing haemocytes suffices to generate hypertrophic organs and the appearance of melanotic tumours. Our results illustrate a novel pro-tumourigenic crosstalk between the p38 MAPK pathway and JAK signalling in a Drosophila model of MPNs. Based on the shared molecular mechanisms underlying MPNs in flies and humans, the interplay between Drosophila JAK and p38 signalling pathways unravelled in this work might have translational relevance for human MPNs. PMID:28237966

  1. Implication of Akt, ERK1/2 and alternative p38MAPK signalling pathways in human colon cancer cell apoptosis induced by green tea EGCG.

    PubMed

    Cerezo-Guisado, María Isabel; Zur, Rafal; Lorenzo, María Jesús; Risco, Ana; Martín-Serrano, Miguel A; Alvarez-Barrientos, Alberto; Cuenda, Ana; Centeno, Francisco

    2015-10-01

    We investigated apoptosis induced by the green tea component the epigallocatechin-3-gallate (EGCG) and the pathways underlying its activity in a colon cancer cell line. A complete understanding of the mechanism(s) and molecules targeted by green tea polyphenols could be useful in developing novel therapeutic approaches for cancer treatment. EGCG, which is the major polyphenol in green tea, has cytotoxic effects and induced cell death in HT-29 cell death. In this study, we evaluated the effect EGCG on mitogen-activated protein kinase (MAPK) and Akt pathways. EGCG treatment increased phospho-ERK1/2, -JNK1/2 and -p38α, -p38γ and -p38δ, as well as phospho-Akt levels. Using a combination of kinase inhibitors, we found that EGCG-induced cell death is partially blocked by inhibiting Akt, ERK1/2 or alternative p38MAPK activity. Our data suggest that these kinase pathways are involved in the anti-cancer effects of EGCG and indicate potential use of this compound as chemotherapeutic agent for colon cancer treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Up-regulation of Siah1 by ethanol triggers apoptosis in neural crest cells through p38 MAPK-mediated activation of p53 signaling pathway.

    PubMed

    Yuan, Fuqiang; Chen, Xiaopan; Liu, Jie; Feng, Wenke; Wu, Xiaoyang; Chen, Shao-Yu

    2017-02-01

    Seven in absentia homolog 1 (Siah1) is one of the E3 ubiquitin ligases and plays a key role in regulating target protein degradation. This study was designed to test the hypothesis that Siah1 mediates ethanol-induced apoptosis in NCCs through p38 MAPK-mediated activation of the p53 signaling pathway. We found that exposure of NCCs to ethanol resulted in the increases in the total protein levels of p53 and the phosphorylation of p53 at serine 15. Ethanol exposure also resulted in a significant increase in the phosphorylation of p38 MAPK. Knock-down of Siah1 dramatically reduced the ethanol-induced increase in the phosphorylation of p38 MAPK. Knock-down of Siah1 by siRNA or down-regulation of p38 MAPK by either siRNA or inhibitor significantly diminished ethanol-induced accumulations of p53 and the phosphorylation of p53. In addition, ethanol exposure resulted in a significant increase in the expression of p53 downstream targets and apoptosis in NCCs, which can be significantly diminished by down-regulation of Siah1 with siRNA. Knock-down of p38 MAPK by siRNA also dramatically reduced the ethanol-induced apoptosis. These results demonstrate that Siah1 plays a crucial role in ethanol-induced apoptosis in NCCs, and that the up-regulation of Siah1 by ethanol can trigger apoptosis through p38 MAPK-mediated activation of the p53 signaling pathway.

  3. 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.

  4. TNFR2 increases the sensitivity of ligand-induced activation of the p38 MAPK and NF-κB pathways and signals TRAF2 protein degradation in macrophages.

    PubMed

    Ruspi, Gerhard; Schmidt, Emily M; McCann, Fiona; Feldmann, Marc; Williams, Richard O; Stoop, A Allart; Dean, Jonathan L E

    2014-04-01

    Tumour necrosis factor (p55 or p60) receptor (TNFR) 1 is the major receptor that activates pro-inflammatory signalling and induces gene expression in response to TNF. Consensus is lacking for the function of (p75 or p80) TNFR2 but experiments in mice have suggested neuro-, cardio- and osteo-protective and anti-inflammatory roles. It has been shown in various cell types to be specifically required for the induction of TNFR-associated factor-2 (TRAF2) degradation and activation of the alternative nuclear factor (NF)-kappaB pathway, and to contribute to the activation of mitogen-activated protein kinases (MAPK) and the classical NF-kappaB pathway. We have investigated the signalling functions of TNFR2 in primary human and murine macrophages. We find that in these cells TNF induces TRAF2 degradation, and this is blocked in TNFR2(-/-) macrophages. TRAF2 has been previously reported to be required for TNF-induced activation of p38 MAPK. However, TRAF2 degradation does not inhibit TNF-induced tolerance of p38 MAPK activation. Neither TNF, nor lipopolysaccharide treatment, induced activation of the alternative NF-kappaB pathway in macrophages. Activation by TNF of the p38 MAPK and NF-kappaB pathways was blocked in TNFR1(-/-) macrophages. In contrast, although TNFR2(-/-) macrophages displayed robust p38 MAPK activation and IkappaBα degradation at high concentrations of TNF, at lower doses the concentration dependence of signalling was weakened by an order of magnitude. Our results suggest that, in addition to inducing TRAF2 protein degradation, TNFR2 also plays a crucial auxiliary role to TNFR1 in sensitising macrophages for the ligand-induced activation of the p38 MAPK and classical NF-kappaB pro-inflammatory signalling pathways. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. 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

  6. Cellular Iron Depletion Stimulates the JNK and p38 MAPK Signaling Transduction Pathways, Dissociation of ASK1-Thioredoxin, and Activation of ASK1*

    PubMed Central

    Yu, Yu; Richardson, Des R.

    2011-01-01

    The role of signaling pathways in the regulation of cellular iron metabolism is becoming increasingly recognized. Iron chelation is used for the treatment of iron overload but also as a potential strategy for cancer therapy, because iron depletion results in cell cycle arrest and apoptosis. This study examined potential signaling pathways affected by iron depletion induced by desferrioxamine (DFO) or di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT). Both chelators affected multiple molecules in the mitogen-activated protein kinase (MAPK) pathway, including a number of dual specificity phosphatases that directly de-phosphorylate MAPKs. Examination of the phosphorylation of major MAPKs revealed that DFO and Dp44mT markedly increased phosphorylation of stress-activated protein kinases, JNK and p38, without significantly affecting the extracellular signal-regulated kinase (ERK). Redox-inactive DFO-iron complexes did not affect phosphorylation of JNK or p38, whereas the redox-active Dp44mT-iron complex significantly increased the phosphorylation of these kinases similarly to Dp44mT alone. Iron or N-acetylcysteine supplementation reversed Dp44mT-induced up-regulation of phospho-JNK, but only iron was able to reverse the effect of DFO on JNK. Both iron chelators significantly reduced ASK1-thioredoxin complex formation, resulting in the increased phosphorylation of ASK1, which activates the JNK and p38 pathways. Thus, dissociation of ASK1 could serve as an important signal for the phosphorylation of JNK and p38 activation observed after iron chelation. Phosphorylation of JNK and p38 likely play an important role in mediating the cell cycle arrest and apoptosis induced by iron depletion. PMID:21378396

  7. 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.

  8. 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.

  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. 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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  13. 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

  14. 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.

  15. 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.

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

    PubMed

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

    2016-04-20

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

  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. [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.

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Inhibition to DRP1 translocation can mitigate p38 MAPK-signaling pathway activation in GMC induced by hyperglycemia.

    PubMed

    Zhang, LieMei; Ji, Ling; Tang, XiaoHong; Chen, XiaoLei; Li, Zi; Mi, XuHua; Yang, LiChuan

    2015-06-01

    Diabetic nephropathy (DN) is a serious complication of diabetes with a poorly defined etiology and limited treatment options. Early intervention is a key to preventing the progression of DN. Dynamin-related protein 1 (DRP1) regulates mitochondrial morphology by promoting its fission and is involved in the pathogenesis of numerous diseases. Furthermore, DRP1 is also closely associated with the development of diabetes, but its functional role in DN remains unknown. This study investigated the effect of DRP1 on early stage of DN. DRP1 expression has increased significantly in glomerular mesangial cell (GMC), which is cultivated in high glucose (HG). Ultra-microstructural changes of nephrons, expression of collagen IV and phosph-p38, ROS production, and mitochondrial function were evaluated and, at the same time, were compared with glomerular mesangial cell (GMC) cultured in normal-glucose (NG), mannitol, and a medium with mitochondrial division inhibitor 1 (Midivi-1). Endogenous DRP1 expression increased in DN. Compared to the control groups ofNG and mannitol, overexpression of DRP1 destroyed pathological changes typical of the GMC, like accumulation of extracellular matrix, and an increase in mitochondria division. In addition, Overexpression of DRP1 promoted the activation of p38, the accumulation of ROS, mitochondrial dysfunction, and the synthesis of collagen IV, and all these changes are suppressed by Midivi-1. This study demonstrates that DRP1 overexpression can accelerate pathological changes in the GMC cultured in HG. Further studies are needed to clarify the underlying mechanism of this destructive function.

  6. 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

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

    PubMed

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

    2005-02-11

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

  8. 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.

  9. 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

  10. 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.

  11. Tristetraprolin Regulates Interleukin-6 Expression Through p38 MAPK-Dependent Affinity Changes with mRNA 3′ Untranslated Region

    PubMed Central

    Zhao, Wenpu; Liu, Min; D'Silva, Nisha J.

    2011-01-01

    Tristetraprolin (TTP) is a well-characterized, zinc finger-containing, RNA-binding protein. TTP targets tumor necrosis factor α for degradation via the 3′ untranslated region (3′UTR). Although AU-rich elements (AREs) in the 3′UTR of interleukin-6 (IL-6) mRNA dictate mRNA degradation, the role of TTP in the post-transcriptional regulation of IL-6 gene expression is unclear. Here we used TTP-deficient mice to test the hypothesis that IL-6 expression is influenced by TTP. Genetic and siRNA-mediated knockdown of TTP resulted in increased IL-6 production and overexpression of TTP had the reverse effect. IL-6 and tumor necrosis factor α production were elevated after injection of IL-1β in TTP-deficient mice. Further, embryonic fibroblasts from these mice (mouse embryonic fibroblasts) exhibited greater IL-6 mRNA expression and longer half-life than wild-type mouse embryonic fibroblasts. Overexpression of TTP reduced IL-6 3′UTR luciferase reporter activity in an ARE-dependent manner. Proximal and distal regions of the 3′UTR acted synergistically to produce the full repression of TTP. Mutation-based luciferase assays show that ARE2, ARE3, and ARE4 are required for TTP-mediated repression. The constitutively activated p38-MK2 pathway abrogated TTP-mediated repression of IL-6 3′UTR reporter activity. RNA immunoprecipitation assay indicated that the deficiency of p38α resulted in the increased affinity of TTP to IL-6 mRNA. Taken together, we propose that TTP downregulates IL-6 gene expression at the post-transcriptional level by targeting ARE elements in the 3′UTR region. PMID:21457063

  12. Hypertensive end-organ damage and premature mortality are p38 mitogen-activated protein kinase-dependent in a rat model of cardiac hypertrophy and dysfunction.

    PubMed

    Behr, T M; Nerurkar, S S; Nelson, A H; Coatney, R W; Woods, T N; Sulpizio, A; Chandra, S; Brooks, D P; Kumar, S; Lee, J C; Ohlstein, E H; Angermann, C E; Adams, J L; Sisko, J; Sackner-Bernstein, J D; Willette, R N

    2001-09-11

    Numerous pathological mediators of cardiac hypertrophy (eg, neurohormones, cytokines, and stretch) have been shown to activate p38 MAPK. The purpose of the present study was to examine p38 MAPK activation and the effects of its long-term inhibition in a model of hypertensive cardiac hypertrophy/dysfunction and end-organ damage. In spontaneously hypertensive stroke-prone (SP) rats receiving a high-salt/high-fat diet (SFD), myocardial p38 MAPK was activated persistently during the development of cardiac hypertrophy and inactivated during decompensation. Long-term oral treatment of SFD-SP rats with a selective p38 MAPK inhibitor (SB239063) significantly enhanced survival over an 18-week period compared with the untreated group (100% versus 50%). Periodic echocardiographic analysis revealed a significant reduction in LV hypertrophy and dysfunction in the SB239063-treatment groups. Little or no difference in blood pressure was noted in the treatment or vehicle groups. Basal and stimulated (lipopolysaccharide) plasma tumor necrosis factor-alpha concentrations were reduced in the SB239063-treatment groups. In vitro vasoreactivity studies demonstrated a significant preservation of endothelium-dependent relaxation in animals treated with the p38 MAPK inhibitor without effects on contraction or NO-mediated vasorelaxation. Proteinuria and the incidence of stroke (53% versus 7%) were also reduced significantly in the SB239063-treated groups. These results demonstrate a crucial role for p38 MAPK in hypertensive cardiac hypertrophy and end-organ damage. Interrupting its function with a specific p38 MAPK inhibitor halts clinical deterioration.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  15. Role of ADAM-17, p38 MAPK, cathepsins, and the proteasome pathway in the synthesis and shedding of fractalkine/CX₃ CL1 in rheumatoid arthritis.

    PubMed

    Jones, Brian A; Riegsecker, Sharayah; Rahman, Ayesha; Beamer, Maria; Aboualaiwi, Wissam; Khuder, Sadik A; Ahmed, Salahuddin

    2013-11-01

    To evaluate the mechanism of fractalkine (FKN)/CX3 CL1 synthesis and shedding in rheumatoid arthritis synovial fibroblasts (RASFs) and in rat adjuvant-induced arthritis (AIA). The effect of tumor necrosis factor α (TNFα) and/or interferon-γ (IFNγ) on FKN synthesis and shedding in human RASFs was determined over time by immunostaining, quantitative reverse transcription-polymerase chain reaction, and Western blotting. The role of protease enzymes and signaling pathways was evaluated using chemical inhibitors and small interfering RNA (siRNA). The activity of 20S proteasome in the lysates and the DNA binding of NF-κB/p65 in the nuclear fractions were evaluated. The in vivo relevance of these findings was examined in rat AIA. In RASFs, stimulation with the combination of TNFα and IFNγ induced cellular expression of FKN within 24 hours. Activation of ADAM-17, but not ADAM-10, partly mediated the proteolytic shedding and release of soluble FKN (sFKN) following TNFα/IFNγ stimulation for 24-72 hours. Compared with control siRNA, ADAM-17 siRNA markedly inhibited TNFα/IFNγ-induced sFKN production (by ∼33%). TNFα/IFNγ-induced sFKN release was markedly suppressed by inhibitors of ADAM-17, p38 MAPK, proteasome, or cathepsin inhibitor but not by inhibitors of caspase 3 or calpain. TNFα/IFNγ-induced proteasome activity also correlated with rapid degradation of IκBα and p38 MAPK phosphorylation. In vivo findings showed increased FKN expression in the joints of rats with AIA, which correlated with increased expression of ADAM-17 and phospho-p38 MAPK. Our results provide new understanding of the role of ADAM-17, p38 MAPK, cathepsins, and the proteasome pathway in FKN expression and shedding. Regulating these pathways may suppress FKN-mediated inflammation and tissue destruction. Copyright © 2013 by the American College of Rheumatology.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Enteroaggregative Escherichia coli flagellin-induced interleukin-8 secretion requires Toll-like receptor 5-dependent p38 MAP kinase activation

    PubMed Central

    Khan, Mohammed A S; Kang, Jian; Steiner, Theodore S

    2004-01-01

    Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen that causes acute and chronic diarrhoea in a number of clinical settings. EAEC diarrhoea involves bacterial aggregation, adherence to intestinal epithelial cells and elaboration of several toxigenic bacterial mediators. Flagellin (FliC-EAEC), a major bacterial surface protein of EAEC, causes interleukin (IL)-8 release from several epithelial cell lines. The host response to flagellins from E. coli and several other bacteria is mediated by Toll-like receptor 5 (TLR5), which signals through nuclear factor kappa B (NF-κB) to induce transcription of pro-inflammatory cytokines. p38 mitogen-activating protein (MAP) kinase (MAPK) is a member of a family of stress-related kinases that influences a diverse range of cellular functions including host inflammatory responses to microbial products. We studied the role of p38 MAPK in FliC-EAEC-induced IL-8 secretion from Caco-2 human intestinal epithelial cells and THP-1 human monocytic cells. We found that IL-8 secretion from both cell types is dependent on p38 MAPK, which is phospho-activated in response to FliC-EAEC. The role of TLR5 in p38 MAPK-dependent IL-8 secretion was verified in HEp-2 cells transiently transfected with a TLR5 expression construct. Activation of interleukin-1 receptor-associated kinase (IRAK) was also observed in Caco-2 and TLR5-transfected HEp-2 cells after exposure to FliC-EAEC. Finally, we demonstrated that pharmacological inhibition of p38 MAPK reduced IL-8 transcription and mRNA levels, but did not affect NF-κB activation. Collectively, our results suggest that TLR5 mediates p38 MAPK-dependent IL-8 secretion from epithelial and monocytic cells incubated with FliC-EAEC, and that this effect requires IL-8 promoter activation independent of NF-κB nuclear migration. PMID:15270737

  1. Inhibition of p38 MAP kinase increases okadaic acid mediated AP-1 expression and DNA binding but has no effect on TRE dependent transcription.

    PubMed

    Rosenberger, S F; Gupta, A; Bowden, G T

    1999-06-17

    By performing in vitro kinase assays we found in papilloma producing 308 mouse keratinocytes that okadaic acid elevated activities of extracellular signal-regulated kinase (ERK) 1/2, c-Jun N-terminal kinases (JNKs) and p38 mitogen-activated protein kinases (MAPKs). This okadaic acid mediated activation of MAP kinases correlated with increased AP-1 binding to a consensus TPA responsive element (TRE) and elevated TRE dependent transcription. To determine the role of p38 MAP kinases in these processes we employed the specific p38 MAP kinase inhibitor SB 203580. Using orthophosphate labeling we showed a decrease in phosphorylation of MAPK activated protein kinase-2 (MAPKAP-K2) indicating reduced activity of p38 MAPKs utilizing this kinase as substrate. In contrast, we found that SB 203580 raised activities of ERK-1/2 and JNKs. Electrophoretic mobility shift assays revealed an increase in TRE binding activity in response to SB 203580 most likely resulting from increased expression of the major TRE binding components JunD and FosB as indicated by Western blot analyses. Increased TRE DNA binding failed to lead to increased transactivation correlating with the inability of SB 203580 to increase phosphorylation of these AP-1 proteins. These data indicate that SB 203580 sensitive p38 MAP kinases are not involved in okadaic acid mediated increases in TRE DNA binding and transactivation.

  2. 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.

  3. Fenofibrate suppresses melanogenesis in B16-F10 melanoma cells via activation of the p38 mitogen-activated protein kinase pathway.

    PubMed

    Huang, Yu-Chun; Liu, Kao-Chih; Chiou, Yi-Ling; Yang, Chao-Hsun; Chen, Tien-Hui; Li, Ting-Ting; Liu, Li-Ling

    2013-10-05

    Fenofibrate and ciglitazone belong to the classes of fibrates and thiazolidinediones, respectively. Their pharmacological actions on peroxisome proliferator-activated receptors (PPARs) present a potential therapy for hyperlipidemia and hyperglycemia. However, the melanogenesis affected by PPAR ligands in melanocytes has not been well investigated. By determining the melanin content of cells treated with PPAR agonists, we showed that fenofibrate significantly reduced melanin synthesis, but its major active metabolite, fenofibric acid, did not. Notably, the suppression of melanogenesis by fenofibrate could not be prevented by the PPARα specific antagonist GW6471. In addition, T0901317, a liver X receptor (LXR) agonist, restored the antimelanogenic activity of fenofibrate. Accordingly, fenofibrate may suppress melanogenesis through a PPARα-independent pathway. Treatment of cells with fenofibrate led to the down-regulated gene expression of melanocortin 1 receptor (MC1R). Fenofibrate also attenuated the dihydroxyphenylalanine (DOPA)-staining activity and expression of tyrosinase as well as the expression of microphthalmia-associated transcription factor (MITF). The phosphorylation of p38 mitogen-activated protein kinase (MAPK) was stimulated by fenofibrate. Furthermore, the p38 MAPK inhibitor SB203580 prevented the repressive effects of fenofibrate on the melanin production. Taken together, the results of the present study suggest that fenofibrate inhibits melanin synthesis via the down-regulation of MC1R, the up-regulation of p38 MAPK, and interference with LXR signaling pathways to decrease the expression of tyrosinase in B16-F10 melanoma cells. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Label transfer reagents to probe p38 MAPK binding partners.

    PubMed

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

    2013-01-21

    Protein kinases are essential enzymes for cellular signaling, 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 signaling proteins. However, the identification of p38-interacting proteins is challenging. For this reason, we have developed label transfer reagents (LTRs) that allow labeling of p38 signaling 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 labeled proteins are detected and/or purified with 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. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. 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

  10. 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

  11. 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

  12. Endothelial damage effects of circulating microparticles from patients with stable angina are reduced by aspirin through ERK/p38 MAPKs pathways.

    PubMed

    Cheng, Gong; Shan, Xue-Feng; Wang, Xu-Lang; Dong, Wei-Wei; Li, Zhe; Liu, Xin-Hong; Zhang, Wei; Xing, Kun; Chang, Feng-Jun

    2017-08-01

    Platelet activation participates in the development of both coronary artery disease (CAD) and circulating microparticles (MPs). As a commonly used medicine for coronary heart disease, whether aspirin affects the function of MPs remains unclear. This study was designed to test MPs from healthy subjects, and stable angina (SA) patients before and after aspirin administration were obtained. MPs origins were tested by flow cytometry. Rat thoracic aortas were incubated with MPs (with or without aspirin) to determine the effects of MPs on expression of ERK1/2, JNKs, and p38 MAPK. Affect on levels of NF-κB, VCAM-1, NO, and O2-. Compared with healthy subjects, MPs concentrations increased in SA patients, but decreased after aspirin administration. According to flow cytometry, aspirin mainly decreased platelet-derived MP. MPs from SA patients decreased the expression of ERK1/2, increased expression of p38 MAPKs, JNKs. Increased NF-κB, VCAM-1, and (O2-) levels decreased NO content. Aspirin therapy significantly inhibited function of MPs from SA patients, and pathway inhibitors (ERK1/2 inhibitor PD98059, p38 MAPKs inhibitor SB203580, NF-kB inhibitor PDTC) show similar effects with aspirin. These results indicate that the pro-inflammatory, oxidative stress, procoagulant, and adhesion properties of MPs can be partly blocked by aspirin via the ERK-NO/O2- and p38 -NF-κB-VCAM-1 signal pathway, which clarified other functions beyond anti-atherothrombotic of aspirin. © 2017 John Wiley & Sons Ltd.

  13. 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.

  14. EGFR activation results in enhanced cyclooxygenase-2 expression through p38 mitogen-activated protein kinase-dependent activation of the Sp1/Sp3 transcription factors in human gliomas.

    PubMed

    Xu, Kaiming; Shu, Hui-Kuo G

    2007-07-01

    Expression of cyclooxygenase-2 (COX-2) has been linked to many cancers and may contribute to malignant phenotypes, including enhanced proliferation, angiogenesis, and resistance to cytotoxic therapies. Malignant gliomas are highly aggressive brain tumors that display many of these characteristics. One prominent molecular abnormality discovered in these astrocytic brain tumors is alteration of epidermal growth factor (EGF) receptor (EGFR) through gene amplification and/or mutation resulting in excessive signaling from this receptor. We found that EGF-mediated stimulation of EGFR tyrosine kinase in human glioma cell lines induces expression of both COX-2 mRNA and protein. The p38 mitogen-activated protein kinase (p38-MAPK) pathway was a strong downstream factor in this activation with inhibition of this pathway leading to strong suppression of COX-2 induction. The p38-MAPK pathway can activate the Sp1/Sp3 transcription factors and this seems necessary for EGFR-dependent transactivation of the COX-2 promoter. Analysis of COX-2 promoter/luciferase constructs revealed that transcriptional activation of the COX-2 promoter by EGFR requires the Sp1 binding site located at -245/-240. Furthermore, Sp1/Sp3 binding to this site in the promoter is enhanced by EGFR activation both in vitro and in vivo. Enhanced DNA binding by Sp1/Sp3 requires p38-MAPK activity and correlates with increased phosphorylation of the Sp1 transcription factor. Thus, EGFR activation in malignant gliomas can transcriptionally activate COX-2 expression in a process that requires p38-MAPK and Sp1/Sp3. Finally, treatment of glioma cell lines with prostaglandin E2, the predominant product of COX-2 activity, results in increased vascular endothelial growth factor expression, thus potentially linking elevations in COX-2 expression with tumor angiogenesis in malignant gliomas.

  15. A cross-talk between the androgen receptor and the epidermal growth factor receptor leads to p38MAPK-dependent activation of mTOR and cyclinD1 expression in prostate and lung cancer cells.

    PubMed

    Recchia, Anna Grazia; Musti, Anna Maria; Lanzino, Marilena; Panno, Maria Luisa; Turano, Ermanna; Zumpano, Rachele; Belfiore, Antonino; Andò, Sebastiano; Maggiolini, Marcello

    2009-03-01

    In androgen sensitive LNCaP prostate cancer cells, the proliferation induced by the epidermal growth factor (EGF) involves a cross-talk between the EGF receptor (EGFR) and the androgen receptor (AR). In lung cancer the role of the EGF-EGFR transduction pathway has been documented, whereas androgen activity has received less attention. Here we demonstrate that in LNCaP and A549 non-small cell lung cancer (NSCLC), AR and EGFR are required for either 5alpha-dihydrotestosterone (DHT) or EGF-stimulated cell growth. Only EGF activated ERK signaling and up-regulated early gene expression, while DHT triggered the expression of classical AR-responsive genes with the exception of the EGF-induced PSA transcript in A549 cells. DHT and EGF up-regulated cyclinD1 (CD1) at both mRNA and protein levels in A549 cells, while in LNCaP cells each mitogen increased only CD1 protein expression. In both cell contexts, CD1 up-regulation was prevented by selective inhibitors as well as by knock-down of either AR or EGFR and also inhibiting p38MAPK and the mammalian target of rapamycin (mTOR) pathways. Interestingly, p38MAPK and mTOR repression prevented the activation of the mTOR target ribosomal p70S6 kinase induced by DHT and EGF, indicating that p38MAPK acts as an upstream mTOR regulator. In addition, the proliferative effects promoted by both DHT and EGF in LNCaP and A549 cancer cells were no longer observed blocking either p38MAPK or mTOR activity. Hence, our data suggest that p38MAPK-dependent activation of the mTOR/CD1 pathway may represent a mechanism through which AR and EGFR cross-talk contributes to prostate and lung cancer progression.

  16. Alamandine reduces leptin expression through the c-Src/p38 MAP kinase pathway in adipose tissue.

    PubMed

    Uchiyama, Tsuyoshi; Okajima, Fumikazu; Mogi, Chihiro; Tobo, Ayaka; Tomono, Shoichi; Sato, Koichi

    2017-01-01

    Obesity is associated with an increased risk of diabetes mellitus, hypertension, and renal dysfunction. Angiotensin 1-7 and alamandine are heptameric renin angiotensin system peptide hormones. Further, alamandine levels increase with renal dysfunction. In the cardiovascular system, angiotensin 1-7 and alamandine produce similar improvements and counterbalance angiotensin II in regulating vascular function. We aimed to determine whether the effect of alamandine on leptin expression and secretion in adipocytes was similar to that of angiotensin 1-7. We studied isolated peri-renal visceral adipose tissue and peri-renal isolated visceral adipocytes from male Wistar rats. Angiotensin II from 0.01 to 10nM had no effect on leptin expression. Angiotensin 1-7 (1 nM) increased leptin secretion and expression, whereas alamandine (1 nM) decreased leptin secretion and expression in adipose tissue and isolated adipocytes and reduced blood leptin levels in vivo. These effects were mediated by Gq, c-Src, p38 mitogen-activated protein, and IκB activation. Additionally, alamandine induced nitric oxide expression via inducible nitric oxidase synthase and plasminogen activator inhibitor 1 expression in adipose tissue and isolated adipocytes. Angiotensin 1-7 and alamandine produced opposing effects on leptin expression and secretion in adipose tissue. This result suggests that the action of Mas (angiotensin 1-7 receptor) and Mas-related G-protein coupled receptor D in adipocytes exhibited opposing actions similar to angiotensin II type 1 and type 2 receptors.

  17. 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. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Acetaminophen attenuates glomerulosclerosis in obese Zucker rats via reactive oxygen species/p38MAPK signaling pathways.

    PubMed

    Wang, Cuifen; Blough, Eric; Arvapalli, Ravikumar; Dai, Xiaoniu; Triest, William E; Leidy, John W; Masannat, Yanal; Wu, Miaozong

    2015-04-01

    Focal segmental glomerulosclerosis is a critical pathological lesion in metabolic syndrome-associated kidney disease that, if allowed to proceed unchecked, can lead to renal failure. However, the exact mechanisms underlying glomerulosclerosis remain unclear, and effective prevention strategies against glomerulosclerosis are currently limited. Herein, we demonstrate that chronic low-dose ingestion of acetaminophen (30 mg/kg/day for 6 months) attenuates proteinuria, glomerulosclerosis, podocyte injury, and inflammation in the obese Zucker rat model of metabolic syndrome. Moreover, acetaminophen treatment attenuated renal fibrosis and the expression of profibrotic factors (fibronectin, connective tissue growth factor, transforming growth factor β), reduced inflammatory cell infiltration into the glomeruli, and decreased the expression of monocyte chemoattractant protein, glutathione (GSH) reductase, and nuclear factor erythroid 2-related factor 2, but increased the level of GSH synthetase in obese animals. Further in vivo and in vitro studies using human renal mesangial cells exposed to high glucose or hydrogen peroxide suggested that the renoprotective effects of acetaminophen are characterized by diminished renal oxidative stress and p38MAPK hyperphosphorylation. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. 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

  20. 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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26337390

  2. 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.

  3. 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.

  4. 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

  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

    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.

  6. 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.

  7. Clinical significance of Wip1 overexpression and its association with the p38MAPK/p53/p16 pathway in NSCLC.

    PubMed

    Yang, Shize; Dong, Siyuan; Qu, Xiaohan; Zhong, Xinwen; Zhang, Qigang

    2017-02-01

    Wip1 is deregulated in numerous human malignancies. However, its roles in non‑small cell lung cancer (NSCLC) remain unclear. In the current study, the expression of Wip1 was investigated in NSCLC and its clinical significance was detected. Immunohistochemical staining was used to measure the expression of (wild‑type p53 induced phosphatase 1) Wip1, p38 mitogen‑activated protein kinase (MAPK), p53, p16 protein in a group of 60 NSCLC and 20 normal lung tissues. In addition, western blotting was performed to detect the Wip1 protein in fresh tissues. The correlations between clinical characteristics and Wip1 expression were analyzed using SPSS, version 16.0 software. The expression of Wip1 was positive in 63.3% (38/60) of NSCLC tissues, and in none of the normal lung tissues (0/20; P<0.01). In addition, Wip1 overexpression was significantly associated with tumor length and differentiation (P=0.008 and 0.03, respectively). The expression of Wip1 was negatively correlated with that of p38MAPK, p53 and p16 (r=‑0.284, ‑0.352 and ‑0.348, respectively). The results of the current study demonstrated that Wip1 was frequently overexpressed in NSCLC, which may serve an essential role in the p38MAPK/p53/p16 signaling pathway.

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

    PubMed

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

    2012-04-01

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

  9. Lactobacillus acidophilus Induces Cytokine and Chemokine Production via NF-κB and p38 Mitogen-Activated Protein Kinase Signaling Pathways in Intestinal Epithelial Cells

    PubMed Central

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

    2012-01-01

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

  10. 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.

  11. Endoplasmic reticulum stress-induced hepatic stellate cell apoptosis through calcium-mediated JNK/P38 MAPK and Calpain/Caspase-12 pathways.

    PubMed

    Huang, Yan; Li, Xiaohui; Wang, Yarui; Wang, Huan; Huang, Cheng; Li, Jun

    2014-09-01

    Recent reports considered that it was the disturbance of calcium homeostasis and the accumulation of misfolded proteins in the endoplasmic reticulum (ER) that activated hepatic stellate cells (HSCs) apoptosis and promoted fibrosis resolution. However, the signal-transducing events that are activated by ER stress after HSCs activation were incompletely understood. In this study, we induced ER stress with thapsigargin (TG), and determined the activation of calpain and the cleavage of caspase by analyzing the protein levels and the correspondingly increased intracellular calcium levels and the induction of the proapoptotic transcription factor CHOP. Moreover, the phosphorylation of JNK and p38 MAPK were followed by the activation of the executioner caspases, caspase-3. As expected, preventing an increase in intracellular calcium levels using intracellular calcium chelators, EGTA, and BAPTA/AM, could substantially inhibit the phosphorylation of JNK and p38 MAPK, abolish the activation of calpains, namely caspase-12, caspase-9, and caspase-3, and provide significant protection for TG-treated activated HSCs. Interestingly, pretreatment with p38 MAPK inhibitor SB202190, JNK inhibitor SP600125, the pan-caspase inhibitor z-VAD-FMK, or calpain inhibitors calpeptin, significantly reduced the cell apoptosis and the cleavage of caspase-12 and caspase-3. However, pretreatment with z-VAD-FMK failed to reduce the activation of calpain. Additionally, pretreatment with SB202190 and SP600125 also decreased the expression of CHOP. Importantly, PDGF-induced collagen Col1α1 and α-smooth muscle actin (α-SMA), markers for the perpetuation phase of HSCs activation, were inhibited in TG-treated activated HSCs. These findings showed that the Calpain/Caspase-12 activation induced by ER stress and the JNK/p38 MAPK phosphorylation induced by the increase of intracellular calcium concentration releasing from ER are the novel signaling pathway underlying the molecular mechanism of fibrosis

  12. Role of TGF-β1/p38 MAPK pathway in hepatitis B virus-induced tubular epithelial-myofibroblast transdifferentiation

    PubMed Central

    Liu, Changhong; Chen, Fengzhe; Han, Xiaochun; Xu, Hui; Wang, Yiguo

    2014-01-01

    Objective: This study is to investigate the hepatitis B virus (HBV)-induced tubular epithelial-myofibroblast transdifferentiation (TEMT) in human renal tubular epithelial HK-2 cells. Methods: Human proximal tubular epithelial HK-2 cells were cultured. These HK-2 cells were divided into 4 groups: the blank control group, the vector control group, the HBV-transfected group, and the inhibitor-treated group. Transfection was performed with lipofectamine. Measurements of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) in culture supernatant were determined by electrochemiluminescence immunoassay. Immunocytochemical staining, reverse transcription PCR (RT-PCR), and Western blot analysis were performed to detect the mRNA and protein expression levels, respectively. Results: The immunocytochemical staining showed that, the expression level of E-cadherin was dramatically decreased, while the α-SMA expression level was significantly elevated, in HBV-transfected HK-2 cells. The mRNA level of TGF-β1 and the protein level of p-p38 mitogen-activated protein kinase (MAPK) were elevated in HK-2 cells transfected with HBV. When treated with the p38 MAPK-specific inhibitor, the activation of p38 MAPK was eliminated in HBV-transfected HK-2 cells. In addition, the altered expression levels of E-cadherin and α-SMA, the increased contents of HBeAg and HBsAg in the culture supernatant, as well as the morphological changes of TEMT in HBV-transfected HK-2 cells, were all reversed by the inhibiter treatment. Conclusion: HBV transfection could induce TEMT in HK-2 cells, which was mediated by the TGF-β1/p38 MAPK pathway. These findings provide new insights into the prevention and treatment of HBV-associated glomerulonephritis. PMID:25550833

  13. 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.

  14. Single Molecule Analysis of Serotonin Transporter Regulation Using Antagonist-Conjugated Quantum Dots Reveals Restricted, p38 MAPK-Dependent Mobilization Underlying Uptake Activation

    PubMed Central

    Chang, Jerry C.; Tomlinson, Ian D.; Warnement, Michael R.; Ustione, Alessandro; Carneiro, Ana M. D.; Piston, David W.; Blakely, Randy D.; Rosenthal, Sandra J.

    2012-01-01

    The presynaptic serotonin (5-HT) transporter (SERT) is targeted by widely prescribed antidepressant medications. Altered SERT expression or regulation has been implicated in multiple neuropsychiatric disorders, including anxiety, depression and autism. Here, we implement a generalizable strategy that exploits antagonist-conjugated quantum dots (Qdots) to monitor, for the first time, single SERT proteins on the surface of serotonergic cells. We document two pools of SERT proteins defined by lateral mobility, one that exhibits relatively free diffusion, and a second, localized to cholesterol and GM1 ganglioside-enriched microdomains, that displays restricted mobility. Receptor-linked signalling pathways that enhance SERT activity mobilize transporters that, nonetheless, remain confined to membrane microdomains. Mobilization of transporters arise from a p38 MAPK-dependent untethering of the SERT C-terminus from the juxtamembrane actin cytoskeleton. Our studies establish the utility of ligand-conjugated Qdots for analysis of the behaviour of single membrane proteins and reveal a physical basis for signaling-mediated SERT regulation. PMID:22745492

  15. Single molecule analysis of serotonin transporter regulation using antagonist-conjugated quantum dots reveals restricted, p38 MAPK-dependent mobilization underlying uptake activation.

    PubMed

    Chang, Jerry C; Tomlinson, Ian D; Warnement, Michael R; Ustione, Alessandro; Carneiro, Ana M D; Piston, David W; Blakely, Randy D; Rosenthal, Sandra J

    2012-06-27

    The presynaptic serotonin (5-HT) transporter (SERT) is targeted by widely prescribed antidepressant medications. Altered SERT expression or regulation has been implicated in multiple neuropsychiatric disorders, including anxiety, depression and autism. Here, we implement a generalizable strategy that exploits antagonist-conjugated quantum dots (Qdots) to monitor, for the first time, single SERT proteins on the surface of serotonergic cells. We document two pools of SERT proteins defined by lateral mobility, one that exhibits relatively free diffusion, and a second, localized to cholesterol and GM1 ganglioside-enriched microdomains, that displays restricted mobility. Receptor-linked signaling pathways that enhance SERT activity mobilize transporters that, nonetheless, remain confined to membrane microdomains. Mobilization of transporters arises from a p38 MAPK-dependent untethering of the SERT C terminus from the juxtamembrane actin cytoskeleton. Our studies establish the utility of ligand-conjugated Qdots for analysis of the behavior of single membrane proteins and reveal a physical basis for signaling-mediated SERT regulation.

  16. MicroRNA-135a is up-regulated and aggravates myocardial depression in sepsis via regulating p38 MAPK/NF-κB pathway.

    PubMed

    Zheng, Ge; Pan, Minli; Jin, Weimin; Jin, Guoxin; Huang, Yumao

    2017-04-01

    MicroRNA-135a (miR-135a) is implicated in the pathological processes of several cancers. However, the roles and regulatory mechanism of miR-135a in sepsis-induced myocardial depression (MD) remain largely unknown. In this study, the serum of patients with sepsis and healthy controls was obtained. The miR-135a expression was then measured. Then lentiviruses (miR-135a mimic, inhibitor and scramble control) were transfected into BALB/c mice. After 4days of transfection, polymicrobial sepsis model was established by cecal ligation and puncture (CLP) surgery. The serum tumor-necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 were detected. Cardiac function was assessed. In addition, the protein expressions of p38 MAPK/NF-κB pathway-related proteins were determined. Besides, SB203580 and JSH-23, the inhibitors of p38 MAPK and NF-κB respectively, were used to treat the isolated ventricular myocytes in vitro. MiR-135a was significantly up-regulated in the serum of patients with sepsis. In comparison with CLP group, the concentrations of TNF-α, IL-1β and IL-6 and the expressions of p-p38 and p-p65 in CLP+miR-135a mimic group were significantly increased, while markedly decreased in CLP+miR-135a inhibitor group. Moreover, EF, FS, LVdP/dt (max), LVdP/dt (min) and LVDP of CLP+miR-135a mimic group were all significantly decreased, while markedly increased in CLP+miR-135a inhibitor group. Besides, the increased expressions of p-p38 and p-p65, decreased expression of p-IKBα and the decreased percentage of contraction amplitude in miR-135a mimic group were markedly reversed by SB203580 or JSH-23 treatments. Up-regulation of miR-135a could aggravate sepsis-induced inflammation and myocardial dysfunction via activation of p38 MAPK/NF-κB pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. Clopidogrel effectively suppresses endothelial microparticle generation induced by indoxyl sulfate via inhibition of the p38 mitogen-activated protein kinase pathway.

    PubMed

    Ryu, Jung-Hwa; Kim, Seung-Jung

    2011-01-01

    Endothelial microparticles (EMPs) are closely associated with vascular dysfunction. We investigated the effects of several drugs on EMP generation in human umbilical vein endothelial cells (HUVECs), and the involvement of the mitogen-activated protein kinase (MAPK) in EMP generation. CD31+CD42-EMP counts were measured by flow cytometry in supernatants of HUVECs incubated with indoxyl sulfate. The EMP responses to losartan, lovastatin, clopidogrel, and mesoglycan were examined. We then measured the effects of MAPK inhibitors on EMPs. (1) Indoxyl sulfate induced EMP release in HUVECs in a dose-dependent fashion; (2) all drugs (10-50 μM) inhibited EMP generation induced by indoxyl sulfate, with clopidogrel being the most effective; (3) the p38 MAPK inhibitor suppressed EMP generation induced by indoxyl sulfate, and (4) clopidogrel significantly suppressed MAPK signaling activated by indoxyl sulfate, with the most potency on p38. The p38 signaling involves EMP generation induced by indoxyl sulfate and is effectively suppressed by clopidogrel. Copyright © 2011 S. Karger AG, Basel.

  3. 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. © 2015 The Authors. Experimental Dermatology Published by John Wiley & Sons Ltd.

  4. 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

  5. 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.

  6. 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.

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

    PubMed Central

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

    2010-01-01

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

  8. MKP1 dependent PTH modulation of bone matrix mineralization in female mice is osteoblast maturation stage specific and involves P-ERK, P-p38 MAPKs

    PubMed Central

    Mahalingam, Chandrika D; Sampathi, Bharat Reddy; Sharma, Sonali; Datta, Tanuka; Das, Varsha; Abou-Samra, Abdul B; Datta, Nabanita S

    2013-01-01

    Limited information is available on the role of MAPK phosphatase1 (MKP1) signaling in osteoblasts. We have recently reported distinct roles for MKP1 during osteoblast proliferation, differentiation and skeletal responsiveness to parathyroid hormone (PTH). Since MKP1 regulates the phosphorylation status of MAPKs we investigated the involvement of P-ERK and P-p38 MAPKs in MKP1 knock out (KO) early and mature osteoblasts with respect to mineralization and PTH response. Calvarial osteoblasts from 9–14 week old wild type (WT) and MKP1 KO male and female mice were examined. Western blot analysis revealed down-regulation and sustained expressions of P-ERK and P-p38 with PTH treatment in differentiated osteoblasts derived from KO males and females respectively. Exposure of early osteoblasts to p38 inhibitor, SB203580 (S), markedly inhibited mineralization in WT and KO osteoblasts from both genders as determined by von Kossa assay. In osteoblasts from males, ERK inhibitor U0126 (U), not p38 inhibitor (S), prevented the inhibitory effects of PTH on mineralization in early or mature osteoblasts. In osteoblasts from KO females, PTH sustained mineralization in early osteoblasts and decreased mineralization in mature cells. This effect of PTH was attenuated by S in early osteoblasts, and by U in mature KO cells. Changes in matrix gla protein (MGP) expression with PTH in KO osteoblasts did not correlate with mineralization, indicative of MKP1 dependent additional mechanisms essential for PTH action on osteoblast mineralization. We conclude that PTH regulation of osteoblast mineralization in female mice is maturation stage specific and involves MKP1 modulation of P-ERK and P-p38 MAPKs. PMID:23197743

  9. MKP1-dependent PTH modulation of bone matrix mineralization in female mice is osteoblast maturation stage specific and involves P-ERK and P-p38 MAPKs.

    PubMed

    Mahalingam, Chandrika D; Sampathi, Bharat Reddy; Sharma, Sonali; Datta, Tanuka; Das, Varsha; Abou-Samra, Abdul B; Datta, Nabanita S

    2013-03-01

    Limited information is available on the role of MAPK phosphatase 1 (MKP1) signaling in osteoblasts. We have recently reported distinct roles for MKP1 during osteoblast proliferation, differentiation, and skeletal responsiveness to parathyroid hormone (PTH). As MKP1 regulates the phosphorylation status of MAPKs, we investigated the involvement of P-ERK and P-p38 MAPKs in MKP1 knockout (KO) early and mature osteoblasts with respect to mineralization and PTH response. Calvarial osteoblasts from 9-14-week-old WT and MKP1 KO male and female mice were examined. Western blot analysis revealed downregulation and sustained expressions of P-ERK and P-p38 with PTH treatment in differentiated osteoblasts derived from KO males and females respectively. Exposure of early osteoblasts to p38 inhibitor, SB203580 (S), markedly inhibited mineralization in WT and KO osteoblasts from both genders as determined by von Kossa assay. In osteoblasts from males, ERK inhibitor U0126 (U), not p38 inhibitor (S), prevented the inhibitory effects of PTH on mineralization in early or mature osteoblasts. In osteoblasts from KO females, PTH sustained mineralization in early osteoblasts and decreased mineralization in mature cells. This effect of PTH was attenuated by S in early osteoblasts and by U in mature KO cells. Changes in matrix Gla protein expression with PTH in KO osteoblasts did not correlate with mineralization, indicative of MKP1-dependent additional mechanisms essential for PTH action on osteoblast mineralization. We conclude that PTH regulation of osteoblast mineralization in female mice is maturation stage specific and involves MKP1 modulation of P-ERK and P-p38 MAPKs.

  10. 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.

  11. Silibinin activated p53 and induced autophagic death in human fibrosarcoma HT1080 cells via reactive oxygen species-p38 and c-Jun N-terminal kinase pathways.

    PubMed

    Duan, Wen-Jun; Li, Qi-Sheng; Xia, Ming-Yu; Tashiro, Shin-ichi; Onodera, Satoshi; Ikejima, Takashi

    2011-01-01

    Our previous research demonstrated that hepatic-protectant silibinin induced autophagy in human fibro-sarcoma HT1080 cells through reactive oxygen species (ROS) pathway. Pifithrin-α (PFT-α), a specific inhibitor of p53, reduced autophagy and reversed silibinin's growth-inhibitory effect; besides, PFT-α decreased the activation of caspase-3, a crucial executor of apoptosis. Silibinin upregulated expression of p53/phosphorylated-p53 (p-p53) in a time-dependent manner. Catalase (scavenger of H(2)O(2)), superoxide dismutase (SOD) (scavenger of O(2)(•-)), and SB203580 (inhibitor of p38) attenuated upregulation of p53 expression, suggesting that p53 might be partially regulated by ROS-p38 pathway. On the other hand, c-Jun N-terminal kinase (JNK) increased autophagic death in silibinin-treated cells, and JNK/p-JNK expression was upregulated by silibinin time-dependently. Inhibition of JNK by SP600125 did not influence generation of ROS. Scavengers of H(2)O(2) or O(2)(•-) showed no effect on expression of JNK/p-JNK, indicating that JNK might not correlate with ROS in this process. However, activation of p53 was suppressed by SP600125; therefore the function of p53 was possibly controlled by JNK as well. Western blotting analysis showed that PFT-α reduced activation of extracellular regulated kinase1/2 (ERK1/2) and expression of protein kinase B (PKB, or Akt)/p-Akt. PD98059 (inhibitor of mitogen-activated protein kinase kinase (MEK)/ERK) and wortmannin (inhibitor of phosphoinositide 3-kinase (PI3K)/Akt) enhanced silibinin's cytotoxicity. Wortmannin augmented silibinin-induced autophagy, while PD98059 did not affect autophagic ratio. These results suggest that silibinin might induce p53-mediated autophagic cell death by activating ROS-p38 and JNK pathways, as well as inhibiting MEK/ERK and PI3K/Akt pathways.

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

    PubMed

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

    2015-11-01

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

  13. 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.

  14. Cold-Inducible Protein RBM3 Protects UV Irradiation-Induced Apoptosis in Neuroblastoma Cells by Affecting p38 and JNK Pathways and Bcl2 Family Proteins.

    PubMed

    Zhuang, Rui-Juan; Ma, Jian; Shi, Xiang; Ju, Fei; Ma, Shuang-Ping; Wang, Lei; Cheng, Bin-Feng; Ma, Yan-Wen; Wang, Mian; Li, Tong; Feng, Zhi-Wei; Yang, Hai-Jie

    2017-08-22

    Induced by hypothermia, cold-inducible protein RBM3 (RNA-binding protein motif 3), has been implicated in neuroprotection against various toxic insults such as hypoxia and ischemia. However, whether mild hypothermia and RBM3 prevent neural cells from UV irradiation-elicited apoptosis is unclear. In the present study, human neuroblastoma cell line SH-SY5Y was used as a cell model for neural cell death, and it was demonstrated that mild hypothermia protects SH-SY5Y cells from UV irradiation-induced apoptosis. However, the protective effect of mild hypothermia was abrogated when RBM3 was silenced. Conversely, the overexpression of RBM3 rescued SH-SY5Y cells from UV-induced apoptosis, as indicated by the decreased levels of cleaved caspase-3 and PARP, and increased cell survival. The analysis on the mechanism underlying RBM3-mediated neuroprotection against UV insult showed that RBM3 could substantially block the activation of p38 and JNK signaling pathways. In addition, the overexpression of RBM3 reduced the expression of pro-apoptotic proteins Bax and Bad, leaving the pro-survival protein Bcl-2 unaffected. In conclusion, RBM3 is the key mediator of mild hypothermia-related protection against UV in neuroblastoma cells, and the neuroprotective effect might be exerted through interfering with pro-apoptotic signaling pathways p38 and JNK and regulating pro-apoptotic proteins Bax and Bad.

  15. IL-6 promotes the expression of vascular endothelial growth factor through the p38 signalling pathway in hypertrophied adenoids in children.

    PubMed

    Wang, Hongtian; Bai, Jing; Zhang, Jing; Yang, Wu; Zuo, Kejun; Li, Huabin

    2013-02-01

    To examine the expression of vascular endothelial growth factor (VEGF) in hypertrophied adenoids in children and investigate the possible regulatory mechanism. Thirty-eight children with hypertrophied adenoids (moderate, 16; severe, 22) were enrolled to investigate the VEGF expression in the adenoid tissues using immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The IL-6 concentration in the nasopharyngeal secretions was measured using an enzyme-linked immunosorbent assay (ELISA). VEGF mRNA expression was further measured in isolated adenoidal cells in vitro after IL-6 stimulation, and the activation of the p38 signalling pathway was determined by Western blot analysis. Our findings showed extensive immunoreactivity of VEGF in the hypertrophied adenoids in children. The levels of VEGF protein and mRNA were significantly higher in severely hypertrophied adenoids than in moderately hypertrophied adenoids (P<0.05). The expression of IL-6 was detectable in the nasopharyngeal secretions, which was significantly associated with the severity of the hypertrophied adenoid. VEGF mRNA expression was upregulated in isolated adenoidal cells in vitro after IL-6 stimulation, and the p38 signalling pathway was activated. The increased expression of VEGF in adenoid tissues suggests a possible role of the IL-6/VEGF axis in the pathogenesis of hypertrophied adenoids in children. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. 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

  17. 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

  18. 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.

  19. 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

  20. X indening oral liquid improves cardiac function of rats with chronic cardiac failure via TGF-ß1/Smad3 and p38 MAPK pathway.

    PubMed

    Wei, Yunliang; Guo, Changsheng; Zhao, Jingsheng; Yang, Jun; Yi, Weiguo; Liu, Hong; Lin, Xinwei; Zhang, Zhengchen

    2017-05-01

    Xindening oral liquid (Xin) is a widely used traditional Chinese medicine for the treatment of chronic heart failure (CHF). However, the exact mechanisms related to its therapeutic effects against CHF remain unclear. In the present study, we investigate the effects of Xin on cardiac function in CHF rats and the possible mechanisms involved. Transverse aortic constriction (TAC) was conducted to induce a CHF rat model in this study. Sixty male Wistar rats were randomly assigned to six groups 28 days after TAC: sham; CHF model; Xin at concentrations of 5 ml/kg, 10 mL/kg, and 20 mL/kg; and QiLi 0.6 g/kg. After four weeks, the rats were treated with Xin (5, 10, or 20 mL/kg/d) for six weeks consecutively. At the end of the study, the cardiac function, heart weight index (HWI) and left ventricular mass index (LVMI), serum level of LDH, B-type natriuretic peptide (BNP), cTnI and CK-MB, and collagen volume fraction were studied. The expression of transforming growth factor-ß1 (TGF-ß1), drosophila mothers against decapentaplegic protein 3 (Smad3), and p38 mitogen activated protein kinase (p38 MAPK) were detected. The results showed that Xin treatment significantly improved cardiac function but decreased the serum level of LDH, BNP, cTnI, and CKMB of CHF rats. In addition, it reduced the HWI, LVMI, and collagen volume fraction compared with the model group. Xin treatment significantly improved cardiac function and attenuated cardiac fibrosis by suppressing the p38 MAPK and TGF-ß1/Smad3 signaling pathway in CHF rats. These results suggested that Xin might be a promising complementary treatment for CHF. More detailed experimental studies will be carried out in our subsequent research.

  1. 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.

  2. 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.

  3. Mesenchymal Stem Cell Conditioned Medium Promotes Proliferation and Migration of Alveolar Epithelial Cells under Septic Conditions In Vitro via the JNK-P38 Signaling Pathway.

    PubMed

    Chen, Jie; Li, Yanqin; Hao, Haojie; Li, Chonghui; Du, Yu; Hu, Ye; Li, Jian; Liang, Zhixin; Li, Chunsun; Liu, Jiejie; Chen, Liangan

    2015-01-01

    Mesenchymal stem cell (MSC) based therapies may be useful for treating acute respiratory distress syndrome (ARDS), but the underlying mechanisms are incompletely understood. We investigated the impact of human umbilical cord Wharton's jelly-derived MSC (hUC-MSC) secreted factors on alveolar epithelial cells under septic conditions and determined the relevant intracellular signaling pathways. Human alveolar epithelial cells (AEC) and primary human small airway epithelial cells (SAEC) were subjected to lipopolysaccharide (LPS) with or without the presence of hUC-MSC-conditioned medium (CM). Proliferation and migration of AEC and SAEC were determined via an MTT assay, a wound healing assay and a transwell migration assay (only for AEC). Protein phosphorylation was determined by western blot and the experiments were repeated in presence of small-molecule inhibitors. The hMSC-secretory proteins were identified by LC-MS/MS mass spectrometry. MSC-CM enhanced proliferation and migration. Activation of JNK and P38, but not ERK, was required for the proliferation and migration of AEC and SAEC. Pretreatment of AEC or SAEC with SP600125, an inhibitor of JNK1 or SB200358, an inhibitor of P38, significantly reduced cell proliferation and migration. An array of proteins including TGF-beta receptor type-1, TGF-beta receptor type-2, Ras-related C3 botulinum toxin substrate 1 and Ras-related C3 botulinum toxin substrate 2 which influencing the proliferation and migration of AEC and SAEC were detected in MSC-CM. Our data suggest MSC promote epithelial cell repair through releasing a repertoire of paracrine factors via activation of JNK and P38 MAPK. © 2015 S. Karger AG, Basel.

  4. 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

  5. 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 no