p38 Mitogen Activated Protein Kinase (MAPK): A New Therapeutic Target for Reducing the Risk of Adverse Pregnancy Outcomes

PubMed Central

Menon, Ramkumar; Papaconstantinou, John

2016-01-01

Introduction Spontaneous preterm birth (PTB) and preterm premature rupture of the membranes (pPROM) remain as a major clinical and therapeutic problem for intervention and management. Current strategies, based on our knowledge of pathways of preterm labor, have only been effective, in part, due to major gaps in our existing knowledge of risks and risk specific pathways. Areas covered Recent literature has identified physiologic aging of fetal tissues as a potential mechanistic feature of normal parturition. This process is affected by telomere dependent and p38 mitogen activated protein kinase (MAPK) induced senescence activation. Pregnancy associated risk factors can cause pathologic activation of this pathway that can cause oxidative stress induced p38 MAPK activation leading to senescence and premature aging of fetal tissues. Premature aging is associated with sterile inflammation capable of triggering preterm labor or preterm premature rupture of membranes. Preterm activation of p38MAPK can be considered as a key contributor to adverse pregnancies. Expert Opinion This review considers p38MAPK activation as a potential target for therapeutic interventions to prevent adverse pregnancy outcomes mediated by stress factors. In this review, we propose multiple strategies to prevent p38MAPK activation and its functional effects. PMID:27459026

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

PubMed Central

Adhikari, Hema; Cullen, Paul J.

2014-01-01

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

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-hemorrhage normalized liver p38 MAPK phosphorylation and iNOS and HIF-1α expression, which was abolished by coadministration of SB203580 or luzindole. Melatonin prevents trauma-hemorrhage-induced liver injury in rats via the melatonin receptor-related, p38 MAPK-dependent iNOS/HIF-1α pathway. Copyright © 2017 the American Physiological Society.

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

PubMed

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

2008-03-01

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

Role of human amnion-derived mesenchymal stem cells in promoting osteogenic differentiation by influencing p38 MAPK signaling in lipopolysaccharide -induced human bone marrow mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yuli; Wu, Hongxia; Shen, Ming

Periodontitis is a chronic inflammatory disease induced by bacterial pathogens, which not only affect connective tissue attachments but also cause alveolar bone loss. In this study, we investigated the anti-inflammatory effects of Human amnion-derived mesenchymal stem cells (HAMSCs) on human bone marrow mesenchymal stem cells (HBMSCs) under lipopolysaccharide (LPS)-induced inflammatory conditions. Proliferation levels were measured by flow cytometry and immunofluorescence staining of 5-ethynyl-2′-deoxyuridine (EdU). Osteoblastic differentiation and mineralization were investigated using chromogenic alkaline phosphatase activity (ALP) activity substrate assays, Alizarin red S staining, and RT-PCR analysis of HBMSCs osteogenic marker expression. Oxidative stress induced by LPS was investigated by assayingmore » reactive oxygen species (ROS) level and superoxide dismutase (SOD) activity. Here, we demonstrated that HAMSCs increased the proliferation, osteoblastic differentiation, and SOD activity of LPS-induced HBMSCs, and down-regulated the ROS level. Moreover, our results suggested that the activation of p38 MAPK signal transduction pathway is essential for reversing the LPS-induced bone-destructive processes. SB203580, a selective inhibitor of p38 MAPK signaling, significantly suppressed the anti-inflammatory effects in HAMSCs. In conclusion, HAMSCs show a strong potential in treating inflammation-induced bone loss by influencing p38 MAPK signaling. - Highlights: • LPS inhibites osteogenic differentiation in HBMSCs via suppression of p38 MAPK signaling pathway. • HAMSCs promote LPS-induced HBMSCs osteogenic differentiation through p38 MAPK signaling pathway. • HAMSCs reverse LPS-induced oxidative stress in LPS-induced HBMSCs through p38 MAPK signaling pathway.« less

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

PubMed

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

2016-01-01

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

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

PubMed Central

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

2016-01-01

Objectives This study aimed to evaluate the effects of ferulic acid (FA) administered at various time points before or after 30 min of middle cerebral artery occlusion (MCAo) followed by 7 d of reperfusion and to examine the involvement of mitogen-activated protein kinase (MAPK) signaling pathways in the cortical penumbra. Methods FA was intravenously administered to rats at a dose of 100 mg/kg 24 h before ischemia (B-FA), 2 h before ischemia (P-FA), immediately after ischemic insult (I-FA), 2 h after reperfusion (R-FA), or 24 h after reperfusion (D-FA). Results Our study results indicated that P-FA, I-FA, and R-FA effectively reduced cerebral infarct areas and neurological deficits. P-FA, I-FA, and R-FA significantly downregulated glial fibrillary acidic protein (GFAP), mitochondrial Bax, cytochrome c, and cleaved caspase-3 expression, and effectively restored the phospho-p38 MAPK (p-p38 MAPK)/p38 MAPK ratio, phospho-90 kDa ribosomal S6 kinase (p-p90RSK) expression, phospho-Bad (p-Bad) expression, the phospho-cAMP response element-binding protein (p-CREB)/CREB ratio, the cytosolic and mitochondrial Bcl-2/Bax ratios, and the cytosolic Bcl-xL/Bax ratio in the cortical penumbra 7 d after reperfusion. SB203580, a specific inhibitor of p38 MAPK, administered 30 min prior to ischemia abrogated the downregulating effects of I-FA on cerebral infarction, and mitochondrial Bax and cleaved caspase-3 expression, and the upregulating effects of I-FA on the p-p38 MAPK/p38 MAPK ratio, p-p90RSK expression, p-Bad expression, and the p-CREB/CREB, and cytosolic and mitochondrial Bcl-2/Bax ratios. Conclusions Our study results thus indicate that P-FA, I-FA, and R-FA effectively suppress reactive astrocytosis and exert neuroprotective effects against cerebral infarction by activating p38 MAPK signaling. The regulating effects of P-FA, I-FA, and R-FA on Bax-induced apoptosis result from activation of the p38 MAPK/p90RSK/CREB/Bcl-2 signaling pathway, and eventually contribute to inhibition of the cytochrome c-mediated caspase-3-dependent apoptotic pathway in the cortical penumbra 7 d after reperfusion. PMID:27187745

Aldosterone Induces Apoptosis in Rat Podocytes: Role of PI3-K/Akt and p38MAPK Signaling Pathways

PubMed Central

Chen, Cheng; Liang, Wei; Jia, Junya; van Goor, Harry; Singhal, Pravin C.; Ding, Guohua

2009-01-01

Background Podocytes play a critical role in the pathogenesis of glomerulosclerosis. Increasing evidence suggests that aldosterone (ALD) is involved in the initiation and progression of glomerular damage. It is, however, unknown whether there is a direct injurious effect of ALD on podocytes. Therefore, in the present study, we evaluated the effect of ALD on podocyte apoptosis and studied the role of phosphatidylinositol 3-kinase/Akt (PI3-K/Akt) and p38 mitogen-activated protein kinase (p38MAPK) signaling pathways in this process. Methods Podocytes were incubated in media containing either buffer or increasing concentrations of ALD (10–9∼10–5M) for variable time periods. The cells were also treated with either wortmannin (inhibitor of PI3-K, 100 nM), SB202190 (SB20, inhibitor of p38MAPK, 10 μM) or buffer. All treatments were performed with or without ALD (10–7M) for 24 h. At the end of the incubation period, apoptosis was evaluated by cell nucleus staining and flow cytometric analyses. Activation of PI3-K/Akt and p38MAPK phosphorylation of cultured rat podocytes was evaluated by performing Akt kinase assay and Western blot, respectively. Results Apoptosis of cultured rat podocytes was induced by ALD in a dose- and time-dependent manner. ALD inhibited the activity of PI3-K/Akt and increased the activation of p38MAPK. PI3-K/Akt activity was further inhibited by the addition of wortmannin to the cells in the presence of ALD. This was accompanied by a significant increase in apoptosis. ALD-induced p38MAPK phosphorylation and apoptosis were inhibited when the cells were pretreated with SB20. Furthermore, treatment with spironolactone not only attenuated the proapoptotic effect of ALD, but also significantly reversed its effects on PI3-K/Akt and p38MAPK signaling pathways. Conclusion ALD induces apoptosis in rat podocytes through inhibition of PI3-K/Akt and stimulation of p38 MAPK signaling pathways. Spironolactone attenuates ALD-induced podocyte apoptosis, thereby positioning this compound as a potential promising target of intervention in human renal damage. PMID:19590239

p38 MAPK pathway is essential for self-renewal of mouse male germline stem cells (mGSCs).

PubMed

Niu, Zhiwei; Mu, Hailong; Zhu, Haijing; Wu, Jiang; Hua, Jinlian

2017-02-01

Male germline stem cells (mGSCs), also called spermatogonial stem cells (SSCs), constantly generate spermatozoa in male animals. A number of preliminary studies on mechanisms of mGSC self-renewal have previously been conducted, revealing that several factors are involved in this regulated process. The p38 MAPK pathway is widely conserved in multiple cell types in vivo, and plays an important role in cell proliferation, differentiation, inflammation and apoptosis. However, its role in self-renewal of mGSCs has not hitherto been determined. Here, the mouse mGSCs were cultured and their identity was verified by semi-RT-PCR, alkaline phosphatase (AP) staining and immunofluorescence staining. Then, the p38 MAPK pathway was blocked by p38 MAPK-specific inhibitor SB202190. mGSC self-renewal ability was then analysed by observation of morphology, cell number, cell growth analysis, TUNEL incorporation assay and cell cycle analysis. Results showed that mouse mGSC self-renewal ability was significantly inhibited by SB202190. This study showed for the first time that the p38 MAPK pathway plays a key role in maintaining self-renewal capacity of mouse mGSCs, which offers a new self-renewal pathway for these cells and contributes to overall knowledge of the mechanisms of mGSC self-renewal. © 2016 John Wiley & Sons Ltd.

Interactions between Sirt1 and MAPKs regulate astrocyte activation induced by brain injury in vitro and in vivo.

PubMed

Li, Dan; Liu, Nan; Zhao, Hai-Hua; Zhang, Xu; Kawano, Hitoshi; Liu, Lu; Zhao, Liang; Li, Hong-Peng

2017-03-29

Astrocyte activation is a hallmark of traumatic brain injury resulting in neurological dysfunction or death for an overproduction of inflammatory cytokines and glial scar formation. Both the silent mating type information (Sirt1) expression and mitogen-activated protein kinase (MAPK) signal pathway activation represent a promising therapeutic target for several models of neurodegenerative diseases. We investigated the potential effects of Sirt1 upregulation and MAPK pathway pharmacological inhibition on astrocyte activation in vitro and in vivo. Moreover, we attempted to confirm the underlying interactions between Sirt1 and MAPK pathways in astrocyte activation after brain injury. The present study employs an interleukin-1β (IL-1β) stimulated primary cortical astrocyte model in vitro and a nigrostriatal pathway injury model in vivo to mimic the astrocyte activation induced by traumatic brain injury. The activation of GFAP, Sirt1, and MAPK pathways were detected by Western blot; astrocyte morphological hypertrophy was assessed using immunofluorescence staining; in order to explore the neuroprotective effect of regulation Sirt1 expression and MAPK pathway activation, the motor and neurological function tests were assessed after injury. GFAP level and morphological hypertrophy of astrocytes are elevated after injury in vitro or in vivo. Furthermore, the expressions of phosphorylated extracellular regulated protein kinases (p-ERK), phosphorylated c-Jun N-terminal kinase (p-JNK), and phosphorylated p38 activation (p-p38) are upregulated, but the Sirt1 expression is downregulated. Overexpression of Sirt1 significantly increases the p-ERK expression and reduces the p-JNK and p-p38 expressions. Inhibition of ERK, JNK, or p38 activation respectively with their inhibitors significantly elevated the Sirt1 expression and attenuated the astrocyte activation. Both the overproduction of Sirt1 and inhibition of ERK, JNK, or p38 activation can alleviate the astrocyte activation, thereby improving the neurobehavioral function according to the modified neurological severity scores (mNSS) and balance latency test. Thus, Sirt1 plays a protective role against astrocyte activation, which may be associated with the regulation of the MAPK pathway activation induced by brain injury in vitro and in vivo.

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.

p38 mitogen-activated protein kinase (MAPK) first regulates filamentous actin at the 8-16-cell stage during preimplantation development.

PubMed

Paliga, Andrew J M; Natale, David R; Watson, Andrew J

2005-08-01

The MAPK (mitogen-activated protein kinase) superfamily of proteins consists of four separate signalling cascades: the c-Jun N-terminal kinase or stress-activated protein kinases (JNK/SAPK); the ERKs (extracellular-signal-regulated kinases); the ERK5 or big MAPK1; and the p38 MAPK group of protein kinases, all of which are highly conserved. To date, our studies have focused on defining the role of the p38 MAPK pathway during preimplantation development. p38 MAPK regulates actin filament formation through the downstream kinases MAPKAPK2/3 (MAPK-activated protein kinase 2/3) or MAPKAPK5 [PRAK (p38 regulated/activated kinase)] and subsequently through HSP25/27 (heat-shock protein 25/27). We recently reported that 2-cell-stage murine embryos treated with cytokine-suppressive anti-inflammatory drugs (CSAIDtrade mark; SB203580 and SB220025) display a reversible blockade of development at the 8-16-cell stage, indicating that p38 (MAPK) activity is required to complete murine preimplantation development. In the present study, we have investigated the stage-specific action and role of p38 MAPK in regulating filamentous actin during murine preimplantation development. Treatment of 8-cell-stage embryos with SB203580 and SB220025 (CSAIDtrade mark) resulted in a blockade of preimplantation development, loss of rhodamine phalloidin fluorescence, MK-p (phosphorylated MAPKAPK2/3), HSP-p (phosphorylated HSP25/27) and a redistribution of alpha-catenin immunofluorescence by 12 h of treatment. In contrast, treatment of 2- and 4-cell-stage embryos with CSAIDtrade mark drugs resulted in a loss of MK-p and HSP-p, but did not result in a loss of rhodamine phalloidin fluorescence. All these effects of p38 MAPK inhibition were reversed upon removal of the inhibitor, and development resumed in a delayed but normal manner to the blastocyst stage. Treatment of 8-cell embryos with PD098059 (ERK pathway inhibitor) did not affect development or fluorescence of MK-p, HSP-p or rhodamine phalloidin. Murine preimplantation development becomes dependent on p38 MAPK at the 8-16-cell stage, which corresponds to the stage when p38 MAPK first regulates filamentous actin during early development.

Rac3 Regulates Cell Invasion, Migration and EMT in Lung Adenocarcinoma through p38 MAPK Pathway

PubMed Central

Zhang, Chenlei; Liu, Tieqin; Wang, Gebang; Wang, Huan; Che, Xiaofang; Gao, Xinghua; Liu, Hongxu

2017-01-01

Background: The role of Rac3 in cell proliferation in lung adenocarcinoma has been tackled in our previous study. However, the role of Rac3 in cell invasion and migration of lung adenocarcinoma is still not clear. Methods: The expression of Rac3 in lung adenocarcinoma specimens and paired noncancerous normal tissues were evaluated by immunohistochemistry. Lentivirus-mediated RNA interference (RNAi) was employed to silence Rac3 in lung adenocarcinoma cell lines A549 and H1299. A p38 MAPK inhibitor (LY2228820) was employed to inhibit activity of p38 MAPK pathway. Cell invasion and migration in vitro were examined by invasion and migration assays, respectively. PathScan® intracellular signaling array kit and western blot were employed in mechanism investigation. Results: Rac3 expression was frequently higher in lung adenocarcinoma than paired noncancerous normal tissues. Rac3 expression was an independent risk factor for lymphonode metastasis, and was associated with worse survival outcome. Silencing of Rac3 inhibited cell invasion and cell migration in lung adenocarcinoma cell lines. Knockdown of Rac3 decreased activity of p38 MAPK pathway. LY2228820, which was an important p38 MAPK inhibitor, inhibited Rac3-induced cell invasion and migration of lung adenocarcinoma. E-cadherin expression was increased and vimentin expression was decreased after silencing of Rac3 or following the treatment of LY2228820. Conclusions: Our findings suggest that Rac3 regulates cell invasion, migration and EMT via p38 MAPK pathway. Rac3 may be a potential biomarker of invasion and metastasis for lung adenocarcinoma, and knockdown of Rac3 may potentially serve as a promising therapeutic target for lung adenocarcinoma. PMID:28900489

Enhanced Expression of WD Repeat-Containing Protein 35 via CaMKK/AMPK Activation in Bupivacaine-Treated Neuro2a Cells

PubMed Central

Huang, Lei; Kondo, Fumio; Gosho, Masahiko; Feng, Guo-Gang; Harato, Misako; Xia, Zhong-yuan; Ishikawa, Naohisa; Fujiwara, Yoshihiro; Okada, Shoshiro

2014-01-01

We previously reported that bupivacaine induces reactive oxygen species (ROS) generation, p38 mitogen-activated protein kinase (MAPK) activation and nuclear factor-kappa B activation, resulting in an increase in expression of WD repeat-containing protein 35 (WDR35) in mouse neuroblastoma Neuro2a cells. However, the identity of signaling upstream of p38 MAPK pathways to WDR35 expression remains unclear. It has been shown that AMP-activated protein kinase (AMPK) can activate p38 MAPK through diverse mechanisms. In addition, several kinases acting upstream of AMPK have been identified including Ca2+/calmodulin-dependent protein kinase kinase (CaMKK). Recent studies reported that AMPK may be involved in bupivacaine-induced cytotoxicity in Schwann cells and in human neuroblastoma SH-SY5Y cells. The present study was undertaken to test whether CaMKK and AMPK are involved in bupivacaine-induced WDR35 expression in Neuro2a cells. Our results showed that bupivacaine induced activation of AMPK and p38 MAPK in Neuro2a cells. The AMPK inhibitors, compound C and iodotubercidin, attenuated the bupivacaine-induced activation of AMPK and p38 MAPK, resulting in an inhibition of the bupivacaine-induced increase in WDR35 expression. Treatment with the CaMKK inhibitor STO-609 also attenuated the bupivacaine-induced activation of AMPK and p38 MAPK, resulting in an inhibition of the bupivacaine-induced increase in WDR35 expression. These results suggest that bupivacaine activates AMPK and p38 MAPK via CaMKK in Neuro2a cells, and that the CaMKK/AMPK/p38 MAPK pathway is involved in regulating WDR35 expression. PMID:24859235

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.

p38 MAPK Signaling in Pemphigus: Implications for Skin Autoimmunity

PubMed Central

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

2013-01-01

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

Glutamate-dependent transcriptional regulation in bergmann glia cells: involvement of p38 MAP kinase.

PubMed

Zepeda, Rossana C; Barrera, Iliana; Castelán, Francisco; Soto-Cid, Abraham; Hernández-Kelly, Luisa C; López-Bayghen, Esther; Ortega, Arturo

2008-07-01

Glutamate (Glu) is the major excitatory neurotransmitter in the Central Nervous System (CNS). Ionotropic and metabotropic glutamate receptors (GluRs) are present in neurons and glial cells and are involved in gene expression regulation. Mitogen-activated proteins kinases (MAPK) are critical for all the membrane to nuclei signaling pathways described so far. In cerebellar Bergmann glial cells, glutamate-dependent transcriptional regulation is partially dependent on p42/44 MAPK activity. Another member of this kinase family, p38 MAPK is activated by non-mitogenic stimuli through its Thr180/Tyr182 phosphorylation and phosphorylates cytoplasmic and nuclear protein targets involved in translational and transcriptional events. Taking into consideration that the role of p38MAPK in glial cells is not well understood, we demonstrate here that glutamate increases p38 MAPK phosphorylation in a time and dose dependent manner in cultured chick cerebellar Bergmann glial cells (BGC). Moreover, p38 MAPK is involved in the glutamate-induced transcriptional activation in these cells. Ionotropic as well as metabotropic glutamate receptors participate in p38 MAPK activation. The present findings demonstrate the involvement of p38 MAPK in glutamate-dependent gene expression regulation in glial cells.

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

PubMed

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

2017-06-01

Obesity often leads to obesity-related cardiac hypertrophy (ORCH), which is suppressed by zinc-induced inactivation of p38 mitogen-activated protein kinase (p38 MAPK). In this study, we investigated the mechanisms by which zinc inactivates p38 MAPK to prevent ORCH. Mice (4-week old) were fed either high fat diet (HFD, 60% kcal fat) or normal diet (ND, 10% kcal fat) containing variable amounts of zinc (deficiency, normal and supplement) for 3 and 6 months. P38 MAPK siRNA and the p38 MAPK inhibitor SB203580 were used to suppress p38 MAPK activity in vitro and in vivo, respectively. HFD activated p38 MAPK and increased expression of B-cell lymphoma/CLL 10 (BCL10) and caspase recruitment domain family member 9 (CARD9). These responses were enhanced by zinc deficiency and attenuated by zinc supplement. Administration of SB203580 to HFD mice or specific siRNA in palmitate-treated cardiomyocytes eliminated the HFD and zinc deficiency activation of p38 MAPK, but did not significantly impact the expression of BCL10 and CARD9. In cultured cardiomyocytes, inhibition of BCL10 expression by siRNA prevented palmitate-induced increased p38 MAPK activation and atrial natriuretic peptide (ANP) expression. In contrast, inhibition of p38 MAPK prevented ANP expression, but did not affect BCL10 expression. Deletion of metallothionein abolished the protective effect of zinc on palmitate-induced up-regulation of BCL10 and phospho-p38 MAPK. HFD and zinc deficiency synergistically induce ORCH by increasing oxidative stress-mediated activation of BCL10/CARD9/p38 MAPK signalling. Zinc supplement ameliorates ORCH through activation of metallothionein to repress oxidative stress-activated BCL10 expression and p38 MAPK activation. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mao, Jiamin

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

TMPYP4 exerted antitumor effects in human cervical cancer cells through activation of p38 mitogen-activated protein kinase.

PubMed

Cheng, Ming-Jun; Cao, Yun-Gui

2017-07-03

The aim of the present study was to investigate the potential effects of the 5,10,15,20-tetrakis (1-methylpyridinium-4-yl) porphyrin (TMPyP4) on the proliferation and apoptosis of human cervical cancer cells and the underlying mechanisms by which TMPyP4 exerted its actions. After human cervical cancer cells were treated with different doses of TMPyP4, cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) method, the apoptosis was observed by flow cytometry (FCM), and the expression of p38 mitogen-activated protein kinase (MAPK), phosphated p38 MAPK (p-p38 MAPK), capase-3, MAPKAPK2 (MK-2) and poly ADP-ribose polymerase (PARP) was measured by Western blot analysis. The analysis revealed that TMPyP4 potently suppressed cell viability and induced the apoptosis of human cervical cancer cells in a dose-dependent manner. In addition, the up-regulation of p-p38 MAPK expression levels was detected in TMPyP4-treated human cervical cancer cells. However, followed by the block of p38 MAPK signaling pathway using the inhibitor SB203580, the effects of TMPyP4 on proliferation and apoptosis of human cervical cancer cells were significantly changed. It was indicated that TMPyP4-inhibited proliferation and -induced apoptosis in human cervical cancer cells was accompanied by activating the p38 MAPK signaling pathway. Taken together, our study demonstrates that TMPyP4 may represent a potential therapeutic method for the treatment of cervical carcinoma.

Increasing Maternal Body Mass Index Is Associated with Systemic Inflammation in the Mother and the Activation of Distinct Placental Inflammatory Pathways1

PubMed Central

Aye, Irving L.M.H.; Lager, Susanne; Ramirez, Vanessa I.; Gaccioli, Francesca; Dudley, Donald J.; Jansson, Thomas; Powell, Theresa L.

2014-01-01

ABSTRACT Obese pregnant women have increased levels of proinflammatory cytokines in maternal circulation and placental tissues. However, the pathways contributing to placental inflammation in obesity are largely unknown. We tested the hypothesis that maternal body mass index (BMI) was associated with elevated proinflammatory cytokines in maternal and fetal circulations and increased activation of placental inflammatory pathways. A total of 60 women of varying pre-/early pregnancy BMI, undergoing delivery by Cesarean section at term, were studied. Maternal and fetal (cord) plasma were collected for analysis of insulin, leptin, IL-1beta, IL-6, IL-8, monocyte chemoattractant protein (MCP) 1, and TNFalpha by multiplex ELISA. Activation of the inflammatory pathways in the placenta was investigated by measuring the phosphorylated and total protein expression of p38-mitogen-activated protein kinase (MAPK), c-Jun-N-terminal kinase (JNK)-MAPK, signal transducer-activated transcription factor (STAT) 3, caspase-1, IL-1beta, IkappaB-alpha protein, and p65 DNA-binding activity. To determine the link between activated placental inflammatory pathways and elevated maternal cytokines, cultured primary human trophoblast (PHT) cells were treated with physiological concentrations of insulin, MCP-1, and TNFalpha, and inflammatory signaling analyzed by Western blot. Maternal BMI was positively correlated with maternal insulin, leptin, MCP-1, and TNFalpha, whereas only fetal leptin was increased with BMI. Placental phosphorylation of p38-MAPK and STAT3, and the expression of IL-1beta protein, were increased with maternal BMI; phosphorylation of p38-MAPK was also correlated with birth weight. In contrast, placental NFkappaB, JNK and caspase-1 signaling, and fetal cytokine levels were unaffected by maternal BMI. In PHT cells, p38-MAPK was activated by MCP-1 and TNFalpha, whereas STAT3 phosphorylation was increased following TNFalpha treatment. Maternal BMI is associated with elevated maternal cytokines and activation of placental p38-MAPK and STAT3 inflammatory pathways, without changes in fetal systemic inflammatory profile. Activation of p38-MAPK by MCP-1 and TNFalpha, and STAT3 by TNFalpha, suggests a link between elevated proinflammatory cytokines in maternal plasma and activation of placental inflammatory pathways. We suggest that inflammatory processes associated with elevated maternal BMI may influence fetal growth by altering placental function. PMID:24759787

Increasing maternal body mass index is associated with systemic inflammation in the mother and the activation of distinct placental inflammatory pathways.

PubMed

Aye, Irving L M H; Lager, Susanne; Ramirez, Vanessa I; Gaccioli, Francesca; Dudley, Donald J; Jansson, Thomas; Powell, Theresa L

2014-06-01

Obese pregnant women have increased levels of proinflammatory cytokines in maternal circulation and placental tissues. However, the pathways contributing to placental inflammation in obesity are largely unknown. We tested the hypothesis that maternal body mass index (BMI) was associated with elevated proinflammatory cytokines in maternal and fetal circulations and increased activation of placental inflammatory pathways. A total of 60 women of varying pre-/early pregnancy BMI, undergoing delivery by Cesarean section at term, were studied. Maternal and fetal (cord) plasma were collected for analysis of insulin, leptin, IL-1beta, IL-6, IL-8, monocyte chemoattractant protein (MCP) 1, and TNFalpha by multiplex ELISA. Activation of the inflammatory pathways in the placenta was investigated by measuring the phosphorylated and total protein expression of p38-mitogen-activated protein kinase (MAPK), c-Jun-N-terminal kinase (JNK)-MAPK, signal transducer-activated transcription factor (STAT) 3, caspase-1, IL-1beta, IkappaB-alpha protein, and p65 DNA-binding activity. To determine the link between activated placental inflammatory pathways and elevated maternal cytokines, cultured primary human trophoblast (PHT) cells were treated with physiological concentrations of insulin, MCP-1, and TNFalpha, and inflammatory signaling analyzed by Western blot. Maternal BMI was positively correlated with maternal insulin, leptin, MCP-1, and TNFalpha, whereas only fetal leptin was increased with BMI. Placental phosphorylation of p38-MAPK and STAT3, and the expression of IL-1beta protein, were increased with maternal BMI; phosphorylation of p38-MAPK was also correlated with birth weight. In contrast, placental NFkappaB, JNK and caspase-1 signaling, and fetal cytokine levels were unaffected by maternal BMI. In PHT cells, p38-MAPK was activated by MCP-1 and TNFalpha, whereas STAT3 phosphorylation was increased following TNFalpha treatment. Maternal BMI is associated with elevated maternal cytokines and activation of placental p38-MAPK and STAT3 inflammatory pathways, without changes in fetal systemic inflammatory profile. Activation of p38-MAPK by MCP-1 and TNFalpha, and STAT3 by TNFalpha, suggests a link between elevated proinflammatory cytokines in maternal plasma and activation of placental inflammatory pathways. We suggest that inflammatory processes associated with elevated maternal BMI may influence fetal growth by altering placental function. © 2014 by the Society for the Study of Reproduction, Inc.

PKCalpha-mediated ERK, JNK and p38 activation regulates the myogenic program in human rhabdomyosarcoma cells.

PubMed

Mauro, Annunziata; Ciccarelli, Carmela; De Cesaris, Paola; Scoglio, Arianna; Bouché, Marina; Molinaro, Mario; Aquino, Angelo; Zani, Bianca Maria

2002-09-15

We have previously suggested that PKCalpha has a role in 12-O-Tetradecanoylphorbol-13-acetate (TPA)-mediated growth arrest and myogenic differentiation in human embryonal rhabdomyosarcoma cells (RD). Here, by monitoring the signalling pathways triggered by TPA, we demonstrate that PKCalpha mediates these effects by inducing transient activation of c-Jun N-terminal protein kinases (JNKs) and sustained activation of both p38 kinase and extracellular signal-regulated kinases (ERKs) (all referred to as MAPKs). Activation of MAPKs following ectopic expression of constitutively active PKCalpha, but not its dominant-negative form, is also demonstrated. We investigated the selective contribution of MAPKs to growth arrest and myogenic differentiation by monitoring the activation of MAPK pathways, as well as by dissecting MAPK pathways using MEK1/2 inhibitor (UO126), p38 inhibitor (SB203580) and JNK and p38 agonist (anisomycin) treatments. Growth-arresting signals are triggered either by transient and sustained JNK activation (by TPA and anisomycin, respectively) or by preventing both ERK and JNK activation (UO126) and are maintained, rather than induced, by p38. We therefore suggest a key role for JNK in controlling ERK-mediated mitogenic activity. Notably, sarcomeric myosin expression is induced by both TPA and UO126 but is abrogated by the p38 inhibitor. This finding indicates a pivotal role for p38 in controlling the myogenic program. Anisomycin persistently activates p38 and JNKs but prevents myosin expression induced by TPA. In accordance with this negative role, reactivation of JNKs by anisomycin, in UO126-pre-treated cells, also prevents myosin expression. This indicates that, unlike the transient JNK activation that occurs in the TPA-mediated myogenic process, long-lasting JNK activation supports the growth-arrest state but antagonises p38-mediated myosin expression. Lastly, our results with the MEK inhibitor suggest a key role of the ERK pathway in regulating myogenic-related morphology in differentiated RD cells.

Puerarin reduces apoptosis in rat hippocampal neurons culturea in high glucose medium by modulating the p38 mitogen activated protein kinase and c-Jun N-terminal kinase signaling pathways.

PubMed

Xu, Xiaohan; Wang, Jingbo; Zhang, Hong; Tian, Guoqing; Liu, Yuqin

2016-02-01

To investigate the neuroprotective etfect of puerarin on rat hippocampal neurons cultured in high glucose medium, and to examine the role of the p38 mitogen activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) signaling pathways in this effect. Primary cultures of hippocampal neurons were prepared from newborn Sprague Dawley rats. Neuron-specific enolase immunocytochemistry was used to identify neurons. The neurons were cultured with normal medium (control group) or with high-glucose medium (high-glucose group), and puerarin (puerarin group), a p38 MAPK inhibitor (SB239063; p38 MAPK inhibitor group) or a JNK inhibitor (SP600125; JNK inhibitor group) were added. After 72 h of treatment, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was performed to detect apoptosis, and western blotting was used to assess protein levels of p-p38, p38, p-JNK and JNK. In the high-glucose group, the neuronal apoptosis rate and the p-p38/p38 and p-JNK/JNK ratios were higher than in the control group. The p38 MAPK and JNK inhibitors prevented this increase in the apoptosis rate. The apoptosis rates in the puerarin group, the p38 MAPK inhibitor group and the JNK inhibitor group were significantly decreased compared with the high-glucose group. Moreover, protein levels of p-p38 and p-JNK were significantly reduced, and the p-p38/p38 and p-JNK/JNK ratios were decreased in the puerarin group compared with the high-glucose group. In addition, compared with the high-glucose group, p-p38 levels and the p-p38/p38 ratio were reduced in the p38 MAPK inhibitor group, and p-JNK levels and the p-JNK/JNK ratio were decreased in the JNK inhibitor group. Puerarin attenuates neuronal apoptosis induced by high glucose by reducing the phosphorylation of p38 and JNK.

Activation of p38 MAPK-regulated Bcl-xL signaling increases survival against zoledronic acid-induced apoptosis in osteoclast precursors.

PubMed

Tai, Ta-Wei; Su, Fong-Chin; Chen, Ching-Yu; Jou, I-Ming; Lin, Chiou-Feng

2014-10-01

The nitrogen-containing bisphosphonate zoledronic acid (ZA) induces apoptosis in osteoclasts and inhibits osteoclast-mediated bone resorption. It is widely used to treat osteoporosis. However, some patients are less responsive to ZA treatment, and the mechanisms of resistance are still unclear. Here, we identified that murine osteoclast precursors may develop resistance to ZA-induced apoptosis. These resistant cells survived the apoptotic effect of ZA following an increase in anti-apoptotic Bcl-xL. Pharmacologically inhibiting Bcl-xL facilitated ZA-induced apoptosis. Treatment with ZA activated p38 MAPK, increasing Bcl-xL expression and cell survival. Nuclear import of β-catenin regulated by p38 MAPK determined Bcl-xL mRNA expression and cell survival in response to ZA. ZA also inactivated glycogen synthase kinase (GSK)-3β, a negative upstream regulator of β-catenin, in a p38 MAPK-mediated manner. Synergistic pharmacological inhibition of p38 MAPK with ZA attenuated receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation and facilitated ZA-induced apoptosis. These results demonstrate that elevated Bcl-xL expression mediated by p38 MAPK-regulated GSK-3β/β-catenin signaling is required for cell survival of ZA-induced apoptosis in both osteoclast precursors and osteoclasts. Finally, we demonstrated that inhibiting p38 MAPK-mediated pathway enhanced ZA effect on increasing the bone mineral density of ovariectomized mice. This result suggests that targeting these pathways may represent a potential therapeutic strategy. Copyright © 2014 Elsevier Inc. All rights reserved.

Adenosine triphosphate as a molecular mediator of the vascular response to injury.

PubMed

Guth, Christy M; Luo, Weifung; Jolayemi, Olukemi; Chadalavada, Kalyan S; Komalavilas, Padmini; Cheung-Flynn, Joyce; Brophy, Colleen M

2017-08-01

Human saphenous veins used for arterial bypass undergo stretch injury at the time of harvest and preimplant preparation. Vascular injury promotes intimal hyperplasia, the leading cause of graft failure, but the molecular events leading to this response are largely unknown. This study investigated adenosine triphosphate (ATP) as a potential molecular mediator in the vascular response to stretch injury, and the downstream effects of the purinergic receptor, P2X7R, and p38 MAPK activation. A subfailure stretch rat aorta model was used to determine the effect of stretch injury on release of ATP and vasomotor responses. Stretch-injured tissues were treated with apyrase, the P2X7R antagonist, A438079, or the p38 MAPK inhibitor, SB203580, and subsequent contractile forces were measured using a muscle bath. An exogenous ATP (eATP) injury model was developed and the experiment repeated. Change in p38 MAPK phosphorylation after stretch and eATP tissue injury was determined using Western blotting. Noninjured tissue was incubated in the p38 MAPK activator, anisomycin, and subsequent contractile function and p38 MAPK phosphorylation were analyzed. Stretch injury was associated with release of ATP. Contractile function was decreased in tissue subjected to subfailure stretch, eATP, and anisomycin. Contractile function was restored by apyrase, P2X7R antagonism, and p38-MAPK inhibition. Stretch, eATP, and anisomycin-injured tissue demonstrated increased phosphorylation of p38 MAPK. Taken together, these data suggest that the vascular response to stretch injury is associated with release of ATP and activation of the P2X7R/P38 MAPK pathway, resulting in contractile dysfunction. Modulation of this pathway in vein grafts after harvest and before implantation may reduce the vascular response to injury. Copyright © 2017 Elsevier Inc. All rights reserved.

Docking, synthesis and pharmacological activity of novel urea-derivatives designed as p38 MAPK inhibitors.

PubMed

de Oliveira Lopes, Raquel; Romeiro, Nelilma Correia; de Lima, Cleverton Kleiton F; Louback da Silva, Leandro; de Miranda, Ana Luisa Palhares; Nascimento, Paulo Gustavo B D; Cunha, Fernando Q; Barreiro, Eliezer J; Lima, Lídia Moreira

2012-08-01

p38 mitogen-activated protein kinase (p38 MAPK) is an important signal transducing enzyme involved in many cellular regulations, including signaling pathways, pain and inflammation. Several p38 MAPK inhibitors have been developed as drug candidates to treatment of autoimmune disorders, such as rheumatoid arthritis. In this paper we reported the docking, synthesis and pharmacological activity of novel urea-derivatives (4a-e) designed as p38 MAPK inhibitors. These derivatives presented good theoretical affinity to the target p38 MAPK, standing out compound 4e (LASSBio-998), which showed a better score value compared to the prototype GK-00687. This compound was able to reduce in vitro TNF-α production and was orally active in a hypernociceptive murine model sensible to p38 MAPK inhibitors. Otherwise, compound 4e presented a dose-dependent analgesic effect in a model of antigen (mBSA)-induced arthritis and anti-inflammatory profile in carrageenan induced paw edema, indicating its potential as a new antiarthritis prototype. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Involvement of histone H3 phosphorylation via the activation of p38 MAPK pathway and intracellular redox status in cytotoxicity of HL-60 cells induced by Vitex agnus-castus fruit extract.

PubMed

Kikuchi, Hidetomo; Yuan, Bo; Yuhara, Eisuke; Imai, Masahiko; Furutani, Ryota; Fukushima, Shin; Hazama, Shingo; Hirobe, Chieko; Ohyama, Kunio; Takagi, Norio; Toyoda, Hiroo

2014-08-01

We have demonstrated that an extract from the ripe fruit of Vitex angus-castus (Vitex), might be a promising anticancer candidate. In order to further provide a molecular rationale for clinical development in anticancer therapy, a detailed mechanism underlying the efficacy of Vitex against HL-60 cells was investigated. Vitex induced a dose- and time-dependent decrease in cell viability associated with induction of apoptosis and G(2)/M cell cycle arrest, both of which were suppressed by the addition of SB203580, an inhibitor for p38 MAPK. Furthermore, SB203580 significantly suppressed Vitex-induced phosphorylation of histone H3, a downstream molecule of p38 MAPK known to be involved in apoptosis induction in tumor cells. Notably, Vitex induced upregulation of intracellular ATP, known to bind its binding pocket inside activated p38 MAPK and to be required for the activation of p38 MAPK pathway. These results, thus, suggest that upregulation of intracellular ATP and phosphorylation of histone H3 are closely associated with the activation of p38 MAPK pathway, consequently contributing to Vitex-mediated cytotoxicity. Intriguingly, a significant decrease of intracellular ROS levels and downregulation of expression level of gp91(phox), an important component of NADPH oxidase, were observed in Vitex-treated cells. A greater decline in ROS levels along with enhanced apoptosis was observed after treatment with Vitex in combination with SnPP, an inhibitor specific for HO-1. Since NADPH oxidase and HO-1 are closely correlated to redox status associated with intracellular ROS levels, the two enzymes are suggested to be implicated in Vitex-mediated cytotoxicity in HL-60 cells by regulating ROS generation. We also suggest that activation of the p38 MAPK pathway may be dependent on the alterations of intracellular ATP levels, rather than that of intracellular ROS levels. These results may have important implications for appropriate clinical uses of Vitex and provide novel insights into the interaction between Vitex and other conventional drugs capable of affecting intracellular redox status.

Neuroprotective Role of a Brain-Enriched Tyrosine Phosphatase, STEP, in Focal Cerebral Ischemia

PubMed Central

Deb, Ishani; Manhas, Namratta; Poddar, Ranjana; Rajagopal, Sathyanarayanan; Allan, Andrea M.; Lombroso, Paul J.; Rosenberg, Gary A.; Candelario-Jalil, Eduardo

2013-01-01

The striatal-enriched phosphatase (STEP) is a component of the NMDA-receptor-mediated excitotoxic signaling pathway, which plays a key role in ischemic brain injury. Using neuronal cultures and a rat model of ischemic stroke, we show that STEP plays an initial role in neuroprotection, during the insult, by disrupting the p38 MAPK pathway. Degradation of active STEP during reperfusion precedes ischemic brain damage and is associated with secondary activation of p38 MAPK. Application of a cell-permeable STEP-derived peptide that is resistant to degradation and binds to p38 MAPK protects cultured neurons from hypoxia-reoxygenation injury and reduces ischemic brain damage when injected up to 6 h after the insult. Conversely, genetic deletion of STEP in mice leads to sustained p38 MAPK activation and exacerbates brain injury and neurological deficits after ischemia. Administration of the STEP-derived peptide at the onset of reperfusion not only prevents the sustained p38 MAPK activation but also reduces ischemic brain damage in STEP KO mice. The findings indicate a neuroprotective role of STEP and suggest a potential role of the STEP-derived peptide in stroke therapy. PMID:24198371

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

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.

Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) activates promyogenic signaling pathways, thereby promoting myoblast differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Sang-Jin; Go, Ga-Yeon; Yoo, Miran

Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) regulates postnatal myogenesis by alleviating myostatin activity, but the molecular mechanisms by which it regulates myogenesis are not fully understood. In this study, we investigate molecular mechanisms of PPARβ/δ in myoblast differentiation. C2C12 myoblasts treated with a PPARβ/δ agonist, GW0742 exhibit enhanced myotube formation and muscle-specific gene expression. GW0742 treatment dramatically activates promyogenic kinases, p38MAPK and Akt, in a dose-dependent manner. GW0742-stimulated myoblast differentiation is mediated by p38MAPK and Akt, since it failed to restore myoblast differentiation repressed by inhibition of p38MAPK and Akt. In addition, GW0742 treatment enhances MyoD-reporter activities. Consistently, overexpression of PPARβ/δmore » enhances myoblast differentiation accompanied by elevated activation of p38MAPK and Akt. Collectively, these results suggest that PPARβ/δ enhances myoblast differentiation through activation of promyogenic signaling pathways. - Highlights: • A PPARβ/δ agonist, GW0742 promotes myoblast differentiation. • GW0742 activates both p38MAPK and Akt activation in myogenic differentiation. • GW0742 enhances MyoD activity for myogenic differentiation. • Overexpression of PPARβ/δ enhances myoblast differentiation via activating promyogenic signaling pathways. • This is the first finding for agonistic mechanism of PPARβ/δ in myogenesis.« less

Crosstalk between Signaling Pathways in Pemphigus: A Role for Endoplasmic Reticulum Stress in p38 Mitogen-Activated Protein Kinase Activation?

PubMed

Cipolla, Gabriel A; Park, Jong Kook; Lavker, Robert M; Petzl-Erler, Maria Luiza

2017-01-01

Pemphigus consists of a group of chronic blistering skin diseases mediated by autoantibodies (autoAbs). The dogma that pemphigus is caused by keratinocyte dissociation (acantholysis) as a distinctive and direct consequence of the presence of autoAb targeting two main proteins of the desmosome-desmoglein (DSG) 1 and/or DSG3-has been put to the test. Several outside-in signaling events elicited by pemphigus autoAb in keratinocytes have been described, among which stands out p38 mitogen-activated protein kinase (p38 MAPK) engagement and its apoptotic effect on keratinocytes. The role of apoptosis in the disease is, however, debatable, to an extent that it may not be a determinant event for the occurrence of acantholysis. Also, it has been verified that compromised DSG trans-interaction does not lead to keratinocyte dissociation when p38 MAPK is inhibited. These examples of conflicting results have been followed by recent work revealing an important role for endoplasmic reticulum (ER) stress in pemphigus' pathogenesis. ER stress is known to activate the p38 MAPK pathway, and vice versa . However, this relationship has not yet been studied in the context of activated signaling pathways in pemphigus. Therefore, by reviewing and hypothetically connecting the role(s) of ER stress and p38 MAPK pathway in pemphigus, we highlight the importance of elucidating the crosstalk between all activated signaling pathways, which may in turn contribute for a better understanding of the role of apoptosis in the disease and a better management of this life-threatening condition.

Activation of the AMP-activated protein kinase-p38 MAP kinase pathway mediates apoptosis induced by conjugated linoleic acid in p53-mutant mouse mammary tumor cells.

PubMed

Hsu, Yung-Chung; Meng, Xiaojing; Ou, Lihui; Ip, Margot M

2010-04-01

Conjugated linoleic acid (CLA) inhibits tumorigenesis and tumor growth in most model systems, an effect mediated in part by its pro-apoptotic activity. We previously showed that trans-10,cis-12 CLA induced apoptosis of p53-mutant TM4t mouse mammary tumor cells through both mitochondrial and endoplasmic reticulum stress pathways. In the current study, we investigated the role of AMP-activated protein kinase (AMPK), a key player in fatty acid metabolism, in CLA-induced apoptosis in TM4t cells. We found that t10,c12-CLA increased phosphorylation of AMPK, and that CLA-induced apoptosis was enhanced by the AMPK agonist 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) and inhibited by the AMPK inhibitor compound C. The increased AMPK activity was not due to nutrient/energy depletion since ATP levels did not change in CLA-treated cells, and knockdown of the upstream kinase LKB1 did not affect its activity. Furthermore, our data do not demonstrate a role for the AMPK-modulated mTOR pathway in CLA-induced apoptosis. Although CLA decreased mTOR levels, activity was only modestly decreased. Moreover, rapamycin, which completely blocked the activity of mTORC1 and mTORC2, did not induce apoptosis, and attenuated rather than enhanced CLA-induced apoptosis. Instead, the data suggest that CLA-induced apoptosis is mediated by the AMPK-p38 MAPK-Bim pathway: CLA-induced phosphorylation of AMPK and p38 MAPK, and increased expression of Bim, occurred with a similar time course as apoptosis; phosphorylation of p38 MAPK was blocked by compound C; the increased Bim expression was blocked by p38 MAPK siRNA; CLA-induced apoptosis was attenuated by the p38 inhibitor SB-203580 and by siRNAs directed against p38 MAPK or Bim. Copyright 2009 Elsevier Inc. All rights reserved.

P38 mitogen-activated protein kinase (p38 MAPK) overexpression in clinical staging of nasopharyngeal carcinoma

NASA Astrophysics Data System (ADS)

Farhat; Asnir, R. A.; Yudhistira, A.; Daulay, E. R.; Muzakkir, M. M.; Yulius, S.

2018-03-01

Molecular biological research on nasopharyngeal carcinoma has been widely practiced, such as VEGF, EGFR, COX-2 expression and so on. MAPK plays a role in cell growth such as proliferation, differentiation, and apoptosis, primarily contributing to gene expression, where p38 MAPK pathway mostly associate with anti-apoptosis and cause cell transformation. The aim of this study is to determine the expression of p38 MAPK in clinical stage of nasopharyngeal carcinoma so that the result can be helpful in prognosis and adjunctive therapy in nasopharyngeal carcinoma. The research design is descriptive. It was done in THT- KL Department of FK USU/RSUP Haji Adam Malik, Medan and Pathology Anatomical Department of FK USU. The study was conducted from December 2011 to May 2012. The Samples are all patients who diagnosed with nasopharyngeal carcinoma in oncology division of Otorhinolaryngology Department. p38 MAPK overexpression was found in 21 samples (70%) from 30 nasopharyngeal carcinoma samples. The elevated of p38 MAPK expression most found on T4 by eight samples (38.1%), N3 lymph node group by nine samples (42.9%), stage IV of clinical staging is as many as 15 samples (71.4%). p38 MAPK most expressed in stage IV clinical staging of patients with nasopharyngeal carcinoma.

PP2A regulates SCF-induced cardiac stem cell migration through interaction with p38 MAPK.

PubMed

Wang, Ying; Xia, Yanli; Kuang, Dong; Duan, Yaqi; Wang, Guoping

2017-12-15

Previous studies have shown that stem cell factor (SCF) induces the migration of cardiac stem cells (CSCs) and helps to repair myocardial infarctions. Earlier studies on the migration mechanism only focused on the activation of kinases; here, we aimed to explore the functional role of protein phosphatase 2A (PP2A) in SCF-induced CSC migration. CSCs were treated with SCF, PP2A enzymatic activity was measured, the phosphorylation levels of PP2A, p38 MAPK and cofilin were evaluated using western blot. Transwell assay was used to determine the migratory ability of CSCs. In vitro, SCF induced the phosphorylation of p38 MAPK and cofilin, leading to the migration of CSCs. Cofilin acted as a downstream signal of p38 MAPK. PP2A was involved in this process. Further studies revealed that PP2A was inactivated via phosphorylation at Tyr307 by SCF and the inactivation/phosphorylation was mediated by activated p38 MAPK, as p38 MAPK inhibitor SB203580 or siRNA prevented SCF-induced inactivation and phosphorylation of PP2A. When CSCs were pretreated with PP2A inhibitor (okadaic acid, OA), SCF-induced CSC migration and the downstream signals were enhanced, and the enhancement was reversed when p38 MAPK was blocked. Additionally, co-immunoprecipitation showed a direct interaction of PP2A with p38 MAPK. Our results indicated that PP2A regulated the SCF-induced activation of p38 MAPK/cofilin signaling pathway and subsequent migration of CSCs by interaction with p38 MAPK. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Two Sulfur Glycoside Compounds Isolated from Lepidium apetalum Willd Protect NRK52e Cells against Hypertonic-Induced Adhesion and Inflammation by Suppressing the MAPK Signaling Pathway and RAAS.

PubMed

Yuan, Peipei; Zheng, Xiaoke; Li, Meng; Ke, Yingying; Fu, Yang; Zhang, Qi; Wang, Xiaolan; Feng, Weisheng

2017-11-12

Lepidium apetalum Willd has been used to reduce edema and promote urination. Cis -desulfoglucotropaeolin ( cis -DG) and trans -desulfoglucotropaeolin ( trans -DG) were isolated from Lepidium apetalum Willd, and caused a significant increase in cell viability in a hypertonic model in NRK52e cells. In the hypertonic model, cis -DG and trans -DG significantly promoted the cell viability of NRK52e cells and inhibited the elevation of Na⁺ in the supernatant, inhibited the renin-angiotensin-aldosterone (RAAS) system, significantly reduced the levels of angiotensin II (Ang II) and aldosterone (ALD), and lowered aquaporin-2 (AQP2) and Na⁺-K⁺ ATP content in renal medulla. After treatment with cis -DG and trans -DG, expression of calcineurin (CAN) and Ca/calmodulin-dependent protein kinase II (CaMK II) was decreased in renal tissue and Ca 2+ influx was inhibited, thereby reducing the secretion of transforming growth factor-β (TGFβ), reversing the increase in adhesion and inflammatory factor E-selectin and monocyte chemotactic protein 1 (MCP-1) induced by high NaCl, while reducing oxidative stress status and decreasing the expression of cyclooxygenase-2 (COX2). Furthermore, inhibition of protein kinase C (PKC) expression also contributed to these improvements. The cis -DG and trans -DG reduced the expression of p-p44/42 MAPK, p-JNK and p-p38, inhibited the phosphorylation of the MAPK signaling pathway in NRN52e cells induced by high salt, decreased the overexpression of p-p38 and p-HSP27, and inhibited the overactivation of the p38-MAPK signaling pathway, suggesting that the p38-MAPK pathway may play a vital role in the hypertonic-induced adhesion and inflammatory response. From the results of this study, it can be concluded that the mechanism of cis -DG and trans -DG may mainly be through inhibiting the p38-MAPK signaling pathway, inhibiting the excessive activation of the RAAS system, and thereby reducing adhesion and inflammatory factors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saito, Yuri, E-mail: saito-yu@bldon.med.osaka-u.ac.jp; Shibayama, Hirohiko; Tanaka, Hirokazu

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

Inhibition of the protein kinase MK-2 protects podocytes from nephrotic syndrome-related injury

PubMed Central

Pengal, Ruma; Guess, Adam J.; Agrawal, Shipra; Manley, Joshua; Ransom, Richard F.; Mourey, Robert J.; Smoyer, William E.

2011-01-01

While mitogen-activated protein kinase (MAPK) activation has been implicated in the pathogenesis of various glomerular diseases, including nephrotic syndrome (NS), its specific role in podocyte injury is not known. We hypothesized that MK-2, a downstream substrate of p38 MAPK, mediates the adverse effects of this pathway and that inhibition of MK-2 would protect podocytes from NS-related injury. Using cultured podocytes, we analyzed 1) the roles of MK-2 and p38 MAPK in puromycin aminonucleoside (PAN)-induced podocyte injury; 2) the ability of specific MK-2 and p38 MAPK inhibitors to protect podocytes against injury; 3) the role of serum albumin, known to induce podocyte injury, in activating p38 MAPK/MK-2 signaling; and 4) the role of p38 MAPK/MK-2 signaling in the expression of Cox-2, an enzyme associated with podocyte injury. Treatment with protein kinase inhibitors specific for both MK-2 (C23, a pyrrolopyridine-type compound) or p38 MAPK (SB203580) reduced PAN-induced podocyte injury and actin cytoskeletal disruption. Both inhibitors reduced baseline podocyte p38 MAPK/MK-2 signaling, as measured by the degree of phosphorylation of HSPB1, a downstream substrate of MK-2, but exhibited disparate effects on upstream signaling. Serum albumin activated p38 MAPK/MK-2 signaling and induced Cox-2 expression, and these responses were blocked by both inhibitors. Given the critical importance of podocyte injury to both NS and other progressive glomerular diseases, these data suggest an important role for p38 MAPK/MK-2 signaling in podocyte injury and identify MK-2 inhibition as a promising potential therapeutic strategy to protect podocytes in various glomerular diseases. PMID:21613416

Thrombin-induced p38 mitogen-activated protein kinase activation is mediated by epidermal growth factor receptor transactivation pathway

PubMed Central

Kanda, Yasunari; Mizuno, Katsushige; Kuroki, Yasutomi; Watanabe, Yasuhiro

2001-01-01

Thrombin is a potent mitogen for vascular smooth muscle cells (VSMC) and has been implicated its pathogenic role in vascular remodelling. However, the signalling pathways by which thrombin mediates its mitogenic response are not fully understood.We have previously reported that thrombin activates p38 mitogen-activated protein kinase (p38 MAPK) by a tyrosine kinase-dependent mechanism, and that p38 MAPK has a role in thrombin-induced mitogenic response in rat VSMC.In the present study, we examine the involvement of epidermal growth factor (EGF) receptor in thrombin-induced p38 MAPK activation. We found that thrombin induced EGF receptor tyrosine phosphorylation (transactivation) in A10 cells, a clonal VSMC cell line. A selective inhibitor of EGF receptor kinase (AG1478) inhibited the p38 MAPK activation in a dose-dependent manner, whereas it had no effect on the response to platelet-derived growth factor (PDGF). EGF receptor phosphorylation induced by thrombin was inhibited by BAPTA-AM and GF109203X, which suggest a requirement for intracellular Ca2+ increase and protein kinase C.We next examined the effect of AG1478 on thrombin-induced DNA synthesis. AG1478 inhibited thrombin-induced DNA synthesis in a dose-dependent manner. In contrast, PDGF-induced DNA synthesis was not affected by AG1478.In conclusion, these data suggest that the EGF receptor transactivation and subsequent p38 MAPK activation is required for thrombin-induced proliferation of VSMC. PMID:11309236

Inhibition of p38 mitogen-activated protein kinase signaling reduces multidrug transporter activity and anti-epileptic drug resistance in refractory epileptic rats.

PubMed

Shao, Yiye; Wang, Cuicui; Hong, Zhen; Chen, Yinghui

2016-03-01

It is widely recognized that P-glycoprotein (P-gp) mediates drug resistance in refractory epilepsy. However, the molecular mechanism underlying the up-regulation of P-gp expression remains unclear. Our previous studies have demonstrated that p38 mitogen-activated protein kinase (MAPK) regulates P-gp expression in cultured K562 cells. However, a lack of in vivo research leaves unanswered questions regarding whether p38MAPK regulates P-gp expression or drug resistance in refractory epilepsy. This in vivo study examined the effects of p38MAPK on the expression of P-gp and mdr1 in the rat brain and quantified antiepileptic drug (AED) concentrations in the hippocampal extracellular fluid. In addition, the role of p38MAPK in electrical and behavioral activity in a rat epilepsy model was studied. The results indicated that p38MAPK inhibition by SB202190 reduced P-gp expression, while increasing AED concentration in the hippocampal extracellular fluid in refractory epileptic rats. SB202190 also reduced the resistance to AEDs in drug-resistant rats and significantly reduced the severity of seizure activity. These results suggest that p38MAPK could participate in drug resistance in refractory epilepsy through the regulation of P-gp. We show that the specific inhibitor of p38MAPK could down-regulate the expression of multidrug transporter (P-glycoprotein) in blood-brain barrier, increase the concentration of antiepileptic drugs in the hippocampal extracellular fluid and reduce anti-epileptic drug resistance in refractory epileptic rats. We propose that the p38MAPK signaling pathway participates in drug resistance in refractory epilepsy through the regulation of P-glycoprotein expression. © 2015 International Society for Neurochemistry.

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

PubMed

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

2016-11-22

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.

Size uniformity of animal cells is actively maintained by a p38 MAPK-dependent regulation of G1-length.

PubMed

Liu, Shixuan; Ginzberg, Miriam Bracha; Patel, Nish; Hild, Marc; Leung, Bosco; Li, Zhengda; Chen, Yen-Chi; Chang, Nancy; Wang, Yuan; Tan, Ceryl; Diena, Shulamit; Trimble, William; Wasserman, Larry; Jenkins, Jeremy L; Kirschner, Marc W; Kafri, Ran

2018-03-29

Animal cells within a tissue typically display a striking regularity in their size. To date, the molecular mechanisms that control this uniformity are still unknown. We have previously shown that size uniformity in animal cells is promoted, in part, by size-dependent regulation of G1 length. To identify the molecular mechanisms underlying this process, we performed a large-scale small molecule screen and found that the p38 MAPK pathway is involved in coordinating cell size and cell cycle progression. Small cells display higher p38 activity and spend more time in G1 than larger cells. Inhibition of p38 MAPK leads to loss of the compensatory G1 length extension in small cells, resulting in faster proliferation, smaller cell size and increased size heterogeneity. We propose a model wherein the p38 pathway responds to changes in cell size and regulates G1 exit accordingly, to increase cell size uniformity. © 2017, Liu et al.

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

PubMed Central

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

2016-01-01

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

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

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

PubMed

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

2017-04-01

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

Power Frequency Magnetic Fields Affect the p38 MAPK-Mediated Regulation of NB69 Cell Proliferation Implication of Free Radicals.

PubMed

Martínez, María Antonia; Úbeda, Alejandro; Moreno, Jorge; Trillo, María Ángeles

2016-04-06

The proliferative response of the neuroblastoma line NB69 to a 100 µT, 50 Hz magnetic field (MF) has been shown mediated by activation of the MAPK-ERK1/2 pathway. This work investigates the MF effect on the cell cycle of NB69, the participation of p38 and c-Jun N-terminal (JNK) kinases in the field-induced proliferative response and the potential involvement of reactive oxygen species (ROS) in the activation of the MAPK-ERK1/2 and -p38 signaling pathways. NB69 cultures were exposed to the 100 µT MF, either intermittently for 24, 42 or 63 h, or continuously for periods of 15 to 120 min, in the presence or absence of p38 or JNK inhibitors: SB203580 and SP600125, respectively. Antioxidant N-acetylcysteine (NAC) was used as ROS scavenger. Field exposure induced transient activation of p38, JNK and ERK1/2. The MF proliferative effect, which was mediated by changes in the cell cycle, was blocked by the p38 inhibitor, but not by the JNK inhibitor. NAC blocked the field effects on cell proliferation and p38 activation, but not those on ERK1/2 activation. The MF-induced proliferative effects are exerted through sequential upregulation of MAPK-p38 and -ERK1/2 activation, and they are likely mediated by a ROS-dependent activation of p38.

Power Frequency Magnetic Fields Affect the p38 MAPK-Mediated Regulation of NB69 Cell Proliferation Implication of Free Radicals

PubMed Central

Martínez, María Antonia; Úbeda, Alejandro; Moreno, Jorge; Trillo, María Ángeles

2016-01-01

The proliferative response of the neuroblastoma line NB69 to a 100 µT, 50 Hz magnetic field (MF) has been shown mediated by activation of the MAPK-ERK1/2 pathway. This work investigates the MF effect on the cell cycle of NB69, the participation of p38 and c-Jun N-terminal (JNK) kinases in the field-induced proliferative response and the potential involvement of reactive oxygen species (ROS) in the activation of the MAPK-ERK1/2 and -p38 signaling pathways. NB69 cultures were exposed to the 100 µT MF, either intermittently for 24, 42 or 63 h, or continuously for periods of 15 to 120 min, in the presence or absence of p38 or JNK inhibitors: SB203580 and SP600125, respectively. Antioxidant N-acetylcysteine (NAC) was used as ROS scavenger. Field exposure induced transient activation of p38, JNK and ERK1/2. The MF proliferative effect, which was mediated by changes in the cell cycle, was blocked by the p38 inhibitor, but not by the JNK inhibitor. NAC blocked the field effects on cell proliferation and p38 activation, but not those on ERK1/2 activation. The MF-induced proliferative effects are exerted through sequential upregulation of MAPK-p38 and -ERK1/2 activation, and they are likely mediated by a ROS-dependent activation of p38. PMID:27058530

Hydrogen saline suppresses neuronal cell apoptosis and inhibits the p38 mitogen‑activated protein kinase‑caspase‑3 signaling pathway following cerebral ischemia‑reperfusion injury.

PubMed

Li, Da; Ai, Yanqiu

2017-10-01

Cerebral ischemia‑reperfusion injury (CIRI) is a serious pathological disease that is associated with a high rate death and disability. Saturated hydrogen (H2) saline exhibits brain protective functions through anti‑inflammatory, antioxidant and antiapoptotic effects. The present study investigated the potential treatment effects of H2 on CIRI. In addition, the potential protective mechanisms of H2 in the prevention of CIRI were investigated. Adult, male Sprague‑Dawley rats (n=60) were randomly divided into the following three groups: Sham‑operated group; IR group; and IR + H2 group (0.6 mmol/l, 0.5 ml/kg/day). Hematoxylin and eosin, and TUNEL staining were performed for histopathological analysis and investigation of apoptosis, respectively. In addition, the protein expression of caspase‑3, p38 mitogen‑activated protein kinase (MAPK) and phosphorylated‑p38 MAPK in the cortex were measured by western blotting analysis. These results demonstrated that H2 significantly reduced the number of apoptotic cells, and the protein expression of p38 MAPK and caspase‑3, compared with the IR group. These effects may be associated with the p38MAPK signaling pathway.

Penehyclidine hydrochloride regulates mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provides cardioprotection in rats with myocardial ischemia-reperfusion injury.

PubMed

Feng, Min; Wang, Lirui; Chang, Siyuan; Yuan, Pu

2018-05-31

The potential mechanism of penehyclidine hydrochloride (PHC) against myocardial ischemia-reperfusion (I/R) injury has not been fully elucidated. The aim of the present study was to reveal whether mitochondrial dynamics, apoptosis, and MAPKs were involved in the cardioprotective effect of this drug on myocardial I/R injury. Ninety healthy adult male Wistar rats were separately pretreated with normal saline (0.9%); PHC; and signal pathway blockers of MAPKs, Drp1, and Bcl-2. Coronary artery ligation and subsequent reperfusion were performed to induce myocardial I/R injury. Echocardiography was performed. Myocardial enzymes and oxidative stress markers were detected. Myocardial cell apoptotic rates and infarct sizes were measured. Mitochondrial function was evaluated. Expression levels of MAPKs, mitochondria regulatory proteins (Drp1, Mfn1/2), and apoptosis-related proteins (Bcl-2, Bax) were determined. PHC pretreatment improved myocardial abnormalities (dysfunction, injury, infarct size, and apoptotic rate), mitochondrial abnormalities (dysfunction and fission), and excessive oxidative stress and inhibited the activities of p38MAPK and JNK signal pathways in rats with myocardial I/R injury (P < 0.05). Additionally, p38MAPK and JNK blockers (SB239063 and SP600125, respectively) had an effect on rats same as that of PHC. Although Drp1 blocker (Mdivi-1) showed a similar cardioprotective effect (P < 0.05), it did not affect the expression of MAPKs and apoptosis-related proteins (P > 0.05). In addition, Bcl-2 blocker (ABT-737) caused a high expression of Drp1 and a low expression of Mfn1/2 (P < 0.05). PHC regulated mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provided cardioprotection in rats with myocardial I/R injury. Copyright © 2018 Elsevier B.V. All rights reserved.

p38 МАРK is Involved in Regulation of Epigenetic Mechanisms of Food Aversion Learning.

PubMed

Grinkevich, L N

2017-08-01

Consolidation of the conditioned food aversion response in Helix lucorum was associated with induction of histone H3 acetylation and methylation. We hypothesized that not only activatory, but also inhibitory p38 MARK-mediated pathways are involved in these processes. To assess the contribution of p38 MAPK to epigenetic processes, we studied the effect p38 MAPK inhibitor SB203580 on acetylation of histone H3 during training of Helix lucorum. Administration of SB203580 decreased learning-induced enhancement of histone H3 acetylation in the CNS of Helix lucorum, which was accompanied by long-term memory impairment. Thus, p38 MAPK is involved in the regulation of epigenetic mechanisms of long-term memory.

Metabolic oxidative stress elicited by the copper(II) complex [Cu(isaepy)2] triggers apoptosis in SH-SY5Y cells through the induction of the AMP-activated protein kinase/p38MAPK/p53 signalling axis: evidence for a combined use with 3-bromopyruvate in neuroblastoma treatment.

PubMed

Filomeni, Giuseppe; Cardaci, Simone; Da Costa Ferreira, Ana Maria; Rotilio, Giuseppe; Ciriolo, Maria Rosa

2011-08-01

We have demonstrated previously that the complex bis[(2-oxindol-3-ylimino)-2-(2-aminoethyl)pyridine-N,N']copper(II), named [Cu(isaepy)(2)], induces AMPK (AMP-activated protein kinase)-dependent/p53-mediated apoptosis in tumour cells by targeting mitochondria. In the present study, we found that p38(MAPK) (p38 mitogen-activated protein kinase) is the molecular link in the phosphorylation cascade connecting AMPK to p53. Transfection of SH-SY5Y cells with a dominant-negative mutant of AMPK resulted in a decrease in apoptosis and a significant reduction in phospho-active p38(MAPK) and p53. Similarly, reverse genetics of p38(MAPK) yielded a reduction in p53 and a decrease in the extent of apoptosis, confirming an exclusive hierarchy of activation that proceeds via AMPK/p38(MAPK)/p53. Fuel supplies counteracted [Cu(isaepy)(2)]-induced apoptosis and AMPK/p38(MAPK)/p53 activation, with glucose being the most effective, suggesting a role for energetic imbalance in [Cu(isaepy)(2)] toxicity. Co-administration of 3BrPA (3-bromopyruvate), a well-known inhibitor of glycolysis, and succinate dehydrogenase, enhanced apoptosis and AMPK/p38(MAPK)/p53 signalling pathway activation. Under these conditions, no toxic effect was observed in SOD (superoxide dismutase)-overexpressing SH-SY5Y cells or in PCNs (primary cortical neurons), which are, conversely, sensitized to the combined treatment with [Cu(isaepy)(2)] and 3BrPA only if grown in low-glucose medium or incubated with the glucose-6-phosphate dehydrogenase inhibitor dehydroepiandrosterone. Overall, the results suggest that NADPH deriving from the pentose phosphate pathway contributes to PCN resistance to [Cu(isaepy)(2)] toxicity and propose its employment in combination with 3BrPA as possible tool for cancer treatment. © The Authors Journal compilation © 2011 Biochemical Society

Tanreqing Injection Attenuates Lipopolysaccharide-Induced Airway Inflammation through MAPK/NF-κB Signaling Pathways in Rats Model

PubMed Central

Liu, Wei; Jiang, Hong-li; Cai, Lin-li; Yan, Min; Dong, Shou-jin; Mao, Bing

2016-01-01

Background. Tanreqing injection (TRQ) is a commonly used herbal patent medicine for treating inflammatory airway diseases in view of its outstanding anti-inflammatory properties. In this study, we explored the signaling pathways involved in contributions of TRQ to LPS-induced airway inflammation in rats. Methods/Design. Adult male Sprague Dawley (SD) rats randomly divided into different groups received intratracheal instillation of LPS and/or intraperitoneal injection of TRQ. Bronchoalveolar Lavage Fluid (BALF) and lung samples were collected at 24 h, 48 h, and 96 h after TRQ administration. Protein and mRNA levels of tumor necrosis factor- (TNF-) α, Interleukin- (IL-) 1β, IL-6, and IL-8 in BALF and lung homogenate were observed by ELISA and real-time PCR, respectively. Lung sections were stained for p38 MAPK and NF-κB detection by immunohistochemistry. Phospho-p38 MAPK, phosphor-extracellular signal-regulated kinases ERK1/2, phospho-SAPK/JNK, phospho-NF-κB p65, phospho-IKKα/β, and phospho-IκB-α were measured by western blot analysis. Results. The results showed that TRQ significantly counteracted LPS-stimulated release of TNF-α, IL-1β, IL-6, and IL-8, attenuated cells influx in BALF, mitigated mucus hypersecretion, suppressed phosphorylation of NF-κB p65, IκB-α, ΙKKα/β, ERK1/2, JNK, and p38 MAPK, and inhibited p38 MAPK and NF-κB p65 expression in rat lungs. Conclusions. Results of the current research indicate that TRQ possesses potent exhibitory effects in LPS-induced airway inflammation by, at least partially, suppressing the MAPKs and NF-κB signaling pathways, in a general dose-dependent manner. PMID:27366191

Activated Rho Kinase Mediates Diabetes-Induced Elevation of Vascular Arginase Activation and Contributes to Impaired Corpora Cavernosa Relaxation: Possible Involvement of p38 MAPK Activation

PubMed Central

Nunes, Kenia P.; Yao, Lin; Liao, James K.; Webb, R. Clinton; Caldwell, Ruth B.; Caldwell, R. William

2013-01-01

Introduction Activated RhoA/Rho kinase (ROCK) has been implicated in diabetes-induced erectile dysfunction. Earlier studies have demonstrated involvement of ROCK pathway in the activation of arginase in endothelial cells. However, signaling pathways activated by ROCK in the penis remain unclear. Aim We tested whether ROCK and p38 MAPK are involved in the elevation of arginase activity and subsequent impairment of corpora cavernosal (CC) relaxation in diabetes. Methods Eight weeks after streptozotocin-induced diabetes, vascular functional studies, arginase activity assay, and protein expression of RhoA, ROCK, phospho-p38 MAPK, p38 MAPK, phospho-MYPT-1Thr850, MYPT-1 and arginase levels were assessed in CC tissues from nondiabetic wild type (WT), diabetic (D) WT (WT + D), partial ROCK 2+/− knockout (KO), and ROCK 2+/− KO + D mice. Main Outcome Measures The expression of RhoA, ROCK 1 and 2, phosphorylation of MYPT-1Thr850 and p38 MAPK, arginase activity/expression, endothelial- and nitrergic-dependent relaxation of CC was assayed. Results Diabetes significantly reduced maximum relaxation (Emax) to both endothelium-dependent acetylcholine (WT + D: Emax; 61 ± 4% vs. WT: Emax; 75 ± 2%) and nitrergic nerve stimulation. These effects were associated with increased expression of active RhoA, ROCK 2, phospho-MYPT-1Thr850, phospho-p38 MAPK, arginase II, and activity of corporal arginase (1.6-fold) in WT diabetic CC. However, this impairment in CC of WT + D mice was absent in heterozygous ROCK 2+/− KO + D mice for acetylcholine (Emax: 80 ± 5%) and attenuated for nitrergic nerve-induced relaxation. CC of ROCK 2+/− KO + D mice showed much less ROCK activity, did not exhibit p38 MAPK activation, and had reduced arginase activity and arginase II expression. These findings indicate that ROCK 2 mediates diabetes-induced elevation of arginase activity. Additionally, pretreatment of WT diabetic CC with inhibitors of arginase (ABH) or p38 MAPK (SB203580) partially prevented impairment of ACh- and nitrergic nerve-induced relaxation and elevation of arginase activity. Conclusion ROCK 2, p38 MAPK and arginase play key roles in diabetes-induced impairment of CC relaxation. PMID:23566117

Schwann Cell Migration Induced by Earthworm Extract via Activation of PAs and MMP2/9 Mediated through ERK1/2 and p38

PubMed Central

Chang, Yung-Ming; Shih, Ying-Ting; Chen, Yueh-Sheng; Liu, Chien-Liang; Fang, Wen-Kuei; Tsai, Chang-Hai; Tsai, Fuu-Jen; Kuo, Wei-Wen; Lai, Tung-Yuan; Huang, Chih-Yang

2011-01-01

The earthworm, which has stasis removal and wound-healing functions, is a widely used Chinese herbal medicine in China. Schwann cell migration is critical for the regeneration of injured nerves. Schwann cells provide an essentially supportive activity for neuron regeneration. However, the molecular migration mechanisms induced by earthworms in Schwann cells remain unclear. Here, we investigate the roles of MAPK (ERK1/2, JNK and p38) pathways for earthworm-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in Schwann cells. Moreover, earthworm induced phosphorylation of ERK1/2 and p38, but not JNK, activate the downstream signaling expression of PAs and MMPs in a time-dependent manner. Earthworm-stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with U0126 and SB203580, resulting in migration and uPA-related signal pathway inhibition. The results were confirmed using small interfering ERK1/2 and p38 RNA. These results demonstrated that earthworms can stimulate Schwann cell migration and up-regulate PAs and MMP2/9 expression mediated through the MAPK pathways, ERK1/2 and p38. Taken together, our data suggests the MAPKs (ERK1/2, p38)-, PAs (uPA, tPA)-, MMP (MMP2, MMP9) signaling pathway of Schwann cells regulated by earthworms might play a major role in Schwann cell migration and nerve regeneration. PMID:19808845

Oxymatrine Inhibits Influenza A Virus Replication and Inflammation via TLR4, p38 MAPK and NF-κB Pathways.

PubMed

Dai, Jian-Ping; Wang, Qian-Wen; Su, Yun; Gu, Li-Ming; Deng, Hui-Xiong; Chen, Xiao-Xuan; Li, Wei-Zhong; Li, Kang-Sheng

2018-03-23

Oxymatrine (OMT) is a strong immunosuppressive agent that has been used in the clinic for many years. In the present study, by using plaque inhibition, luciferase reporter plasmids, qRT-PCR, western blotting, and ELISA assays, we have investigated the effect and mechanism of OMT on influenza A virus (IAV) replication and IAV-induced inflammation in vitro and in vivo. The results showed that OMT had excellent anti-IAV activity on eight IAV strains in vitro. OMT could significantly decrease the promoter activity of TLR3, TLR4, TLR7, MyD88, and TRAF6 genes, inhibit IAV-induced activations of Akt, ERK1/2, p38 MAPK, and NF-κB pathways, and suppress the expressions of inflammatory cytokines and MMP-2/-9. Activators of TLR4, p38 MAPK and NF-κB pathways could significantly antagonize the anti-IAV activity of OMT in vitro, including IAV replication and IAV-induced cytopathogenic effect (CPE). Furthermore, OMT could reduce the loss of body weight, significantly increase the survival rate of IAV-infected mice, decrease the lung index, pulmonary inflammation and lung viral titter, and improve pulmonary histopathological changes. In conclusion, OMT possesses anti-IAV and anti-inflammatory activities, the mechanism of action may be linked to its ability to inhibit IAV-induced activations of TLR4, p38 MAPK, and NF-κB pathways.

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.

Osthole attenuates hepatic injury in a rodent model of trauma-hemorrhage.

PubMed

Yu, Huang-Ping; Liu, Fu-Chao; Tsai, Yung-Fong; Hwang, Tsong-Long

2013-01-01

Recent evidences show that osthole possesses anti-inflammatory properties and protective effects following shock-like states, but the mechanism of these effects remains unknown. The p38 mitogen-activated protein kinase (p38 MAPK) pathway exerts anti-inflammatory effects in injury. The aim of this study was to investigate whether p38 MAPK plays any role in the osthole-mediated attenuation of hepatic injury after trauma-hemorrhage. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure maintained at approximately 35-40 mmHg for 90 minutes), followed by fluid resuscitation. During resuscitation, a single dose of osthole (3 mg/kg, intravenously) with and without a p38 MAPK inhibitor SB-203580 (2 mg/kg, intravenously), SB-203580 or vehicle was administered. Plasma alanine aminotransferase (ALT) with aspartate aminotransferase (AST) concentrations and various hepatic parameters were measured (n = 8 rats/group) at 24 hours after resuscitation. The results showed that trauma-hemorrhage increased hepatic myeloperoxidase activity, intercellular adhesion molecule-1 and interleukin-6 levels, and plasma ALT and AST concentrations. These parameters were significantly improved in the osthole-treated rats subjected to trauma-hemorrhage. Osthole treatment also increased hepatic phospho-p38 MAPK expression compared with vehicle-treated trauma-hemorrhaged rats. Co-administration of SB-203580 with osthole abolished the osthole-induced beneficial effects on the above parameters and hepatic injury. These results suggest that the protective effect of osthole administration on alleviation of hepatic injury after trauma-hemorrhage, which is, at least in part, through p38 MAPK-dependent pathway.

Autoantibodies in the Autoimmune Disease Pemphigus Foliaceus Induce Blistering via p38 Mitogen-Activated Protein Kinase-Dependent Signaling in the Skin

PubMed Central

Berkowitz, Paula; Chua, Michael; Liu, Zhi; Diaz, Luis A.; Rubenstein, David S.

2008-01-01

Pemphigus foliaceus (PF) is a human autoimmune blistering disease in which a humoral immune response targeting the skin results in a loss of keratinocyte cell-cell adhesion in the superficial layers of the epidermal epithelium. In PF, desmoglein-1-specific autoantibodies induce blistering. Evidence is beginning to accumulate that activation of signaling may have an important role in the ability of pathogenic pemphigus IgGs to induce blistering and that both p38 mitogen-activated protein kinase (MAPK) and heat shock protein (HSP) 27 are part of this signaling pathway. This study was undertaken to investigate the ability of PF IgGs to activate signaling as well as the contribution of this signaling pathway to blister induction in an in vivo model of PF. Phosphorylation of both p38 MAPK and HSP25, the murine HSP27 homolog, was observed in the skin of PF IgG-treated mice. Furthermore, inhibition of p38 MAPK blocked the ability of PF IgGs to induce blistering in vivo. These results indicate that PF IgG-induced blistering is dependent on activation of p38 MAPK in the target keratinocyte. Rather than influencing the immune system, limiting the autoantibody-induced intracellular signaling response that leads to target end-organ damage may be a more viable therapeutic strategy for the treatment of autoimmune diseases. Inhibition of p38 MAPK may be an effective strategy for the treatment of PF. PMID:18988808

IL-17A causes depression-like symptoms via NFκB and p38MAPK signaling pathways in mice: Implications for psoriasis associated depression.

PubMed

Nadeem, Ahmed; Ahmad, Sheikh F; Al-Harbi, Naif O; Fardan, Ali S; El-Sherbeeny, Ahmed M; Ibrahim, Khalid E; Attia, Sabry M

2017-09-01

Psoriasis has been shown to be associated with an increased prevalence of comorbid major depression. IL-17A plays an important role in both depression and psoriasis. IL-17A has been shown to be elevated in systemic circulation of psoriatic patients. IL-17A released from different immune cells during psoriasis may be responsible for the development of neuropsychiatric symptoms associated with depression. Therefore, this study explored the association of systemic IL-17A with depression. The present study utilized imiquimod model of psoriatic inflammation as well as IL-17A administration in mice to investigate the effect of IL-17A on depression-like behavior. Psoriatic inflammation led to enhanced IL-17A expression in peripheral immune cells of both innate and adaptive origin. This was associated with increased NFκB/p38MAPK signaling and inflammatory mediators in different brain regions, and depression-like symptoms (as reflected by sucrose preference and tail suspension tests). The role of IL-17A was further confirmed by administering it alone for ten days, followed by assessment of the same parameters. IL-17A administration produced effects similar to psoriasis-like inflammation on neurobehavior and NFκB/p38MAPK pathways. Moreover, both NFκB and p38MAPK inhibitors led to attenuation in IL-17A associated with depression-like behavior via reduction in inflammatory mediators, such as MCP-1, iNOS, IL-6, and CXCL-2. Furthermore, anti-IL17A antibody also led to a reduction in imiquimod-induced depression-like symptoms, as well as NFκB/p38MAPK signaling. The present study shows that IL-17A plays an important role in comorbid depression associated with psoriatic inflammation, where both NFκB and p38MAPK pathways play significant roles via upregulation of inflammatory mediators in the brain. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

Liu, Zhi-Feng; Zheng, Dong; Fan, Guo-Chang; Peng, Tianqing; Su, Lei

2016-08-01

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

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

PubMed Central

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

2016-01-01

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

Human prostate luminal cell differentiation requires NOTCH3 induction by p38-MAPK and MYC.

PubMed

Frank, Sander B; Berger, Penny L; Ljungman, Mats; Miranti, Cindy K

2017-06-01

Many pathways dysregulated in prostate cancer are also involved in epithelial differentiation. To better understand prostate tumor initiation, we sought to investigate specific genes and mechanisms required for normal basal to luminal cell differentiation. Utilizing human prostate basal epithelial cells and an in vitro differentiation model, we tested the hypothesis that regulation of NOTCH3 by the p38 MAPK family (hereafter p38-MAPK), via MYC, is required for luminal differentiation. Inhibition (SB202190 and BIRB796) or knockdown of p38α (also known as MAPK14) and/or p38δ (also known as MAPK13) prevented proper differentiation. Additionally, treatment with a γ-secretase inhibitor (RO4929097) or knockdown of NOTCH1 and/or NOTCH3 greatly impaired differentiation and caused luminal cell death. Constitutive p38-MAPK activation through MKK6(CA) increased NOTCH3 (but not NOTCH1) mRNA and protein levels, which was diminished upon MYC inhibition (10058-F4 and JQ1) or knockdown. Furthermore, we validated two NOTCH3 enhancer elements through a combination of enhancer (e)RNA detection (BruUV-seq) and luciferase reporter assays. Finally, we found that the NOTCH3 mRNA half-life increased during differentiation or upon acute p38-MAPK activation. These results reveal a new connection between p38-MAPK, MYC and NOTCH signaling, demonstrate two mechanisms of NOTCH3 regulation and provide evidence for NOTCH3 involvement in prostate luminal cell differentiation. © 2017. Published by The Company of Biologists Ltd.

[Effect of P38MAPK signal transduction pathway on apoptosis of THP-1 induced by allicin].

PubMed

Liao, Yang; Chen, Jianbin; Tang, Weixue; Ge, Qunfang; Lu, Qianwei; Yang, Zesong

2009-06-01

The objective of this paper was to study the change of P38MAPK and Fas in the apoptosis of THP-1 cells induced by allicin. The proliferation inhibition rates of THP-1 cells after various treatments were examined by MTT assay. Apoptosis rate was determined with Annexin V- FITC/PI double staining by flow cytometry. The expression and distribution change of the phosphorylation p38MAPK (P-p38MAPK) were detected by immunohistochemical staining. The changes of P-p38 MAPK and Fas proteins were detected by Western blot. The proliferations of leukemia cell line THP-1 are inhibited by allicin. MTT assay showed that allicin can inhibit the proliferation of the THP-1 cell, and the inhibition was dependent on both dose and time. The IC50 of 72 hours was 12.8 mg x L(-1). Apoptosis rate detected by Annexin V-FITC/PI was proportional to the concentration of the allicin. After the immunohistochemical staining test, the P-p38MAPK was located in the cell nucleus and plasma, showing deep brown, when adding allicin to THP-1 cell. Western blot test showed that the P-p38MAPK proteins expression was proportional to the concentration of Allicin and was also dose dependent. The levels of P-p38MAPK in negative control group, 1/2 IC50 of 72 hours group and IC50 of 72 hours group were 0.259 8 +/- 0.013 2, 0.61 2 +/- 0.008 3 and 0.505 6 +/- 0.005 5 respectively, and the levels of Fas proteins were 0.287 4 +/- 0.008 9, 0.426 8 +/- 0.007 9 and 0.597 1 +/- 0.010 9 respectively. The difference was statistically significant when compared with the negative control group (P < 0.01). Allicin can significantly induce THP-1 cells apoptosis, and its mechanism may be related to the activation of P38MAPK/Fas.

Strategies of biochemical adaptation for hibernation in a South American marsupial Dromiciops gliroides: 1. Mitogen-activated protein kinases and the cell stress response.

PubMed

Wijenayake, Sanoji; Luu, Bryan E; Zhang, Jing; Tessier, Shannon N; Quintero-Galvis, Julian F; Gaitán-Espitia, Juan Diego; Nespolo, Roberto F; Storey, Kenneth B

2017-12-14

Hibernation is a period of torpor and heterothermy that is typically associated with a strong reduction in metabolic rate, global suppression of transcription and translation, and upregulation of various genes/proteins that are central to the cellular stress response such as protein kinases, antioxidants, and heat shock proteins. The current study examined cell signaling cascades in hibernating monito del monte, Dromiciops gliroides, a South American marsupial of the Order Microbiotheria. Responses to hibernation by members of the mitogen-activated protein kinase (MAPK) pathways, and their roles in coordinating hibernator metabolism were examined in liver, kidney, heart and brain of control and versus hibernating (4days continuous torpor) D. gliroides. The targets evaluated included key protein kinases in their activated phosphorylated forms (p-ERK/MAPK 1/2, p-MEK1, p-MSK1, p-p38, p-JNK) and related target proteins (p-CREB 2, p-ATF2, p-c-Jun and p-p53). Liver exhibited a strong coordinated response by MAPK members to hibernation with significant increases in protein phosphorylation levels of p-MEK1, p-ERK/MAPK1/2, p-MSK1, p-JNK and target proteins c-Jun, and p-ATF2, all combining to signify a strong activation of MAPK signaling during hibernation. Kidney also showed activation of MAPK cascades with significant increases in p-MEK1, p-ERK/MAPK1/2, p-p38, and p-c-Jun levels in hibernating animals. By contrast, responses by heart and brain indicated reduced MAPK pathway function during torpor with reduced phosphorylation of targets including p-ERK/MAPK 1/2 in both tissues as well as lower p-p38 and p-JNK content in heart. Overall, the data indicate a vital role for MAPK signaling in regulating the cell stress response during marsupial hibernation. Copyright © 2017 Elsevier Inc. All rights reserved.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Inhibitors of stress-activated protein/mitogen-activated protein kinase pathways.

PubMed

Malemud, Charles J

2007-06-01

The importance of stress-activated protein/mitogen-activated protein kinase (SAP/MAPK) pathway signalling (involving c-Jun-N-terminal kinase [JNK], extracellular signal-regulated kinase [ERK] and p38 kinase) in normal cellular proliferation, differentiation and programmed cell death has led to significant recent advances in our understanding of the role of SAP/MAPK signaling in inflammatory disorders such as arthritis and cardiovascular disease, cancer, and pulmonary and neurogenerative diseases. The discovery that several natural products such as resveratrol, tangeretin and ligustilide non-specifically inhibit SAP/MAPK signalling in vitro should now be logically extended to studies designed to determine how agents in these natural products regulate SAP/MAPK pathways in animal models of disease. A new generation of small-molecule SAP/MAPK inhibitors that demonstrate increasing specificity for each of the JNK, ERK and p38 kinase isoforms has shown promise in animal studies and could eventually prove effective for treating human diseases. Several of these compounds are already being tested in human subjects to assess their oral bioavailability, pharmacokinetics and toxicity.

Roles of mitogen-activated protein kinases and angiotensin II in renal development.

PubMed

Balbi, A P C; Francescato, H D C; Marin, E C S; Costa, R S; Coimbra, T M

2009-01-01

Experimental and clinical evidence suggests that angiotensin II (AII) participates in renal development. Renal AII content is several-fold higher in newborn rats and mice than in adult animals. AII receptors are also expressed in higher amounts in the kidneys of newborn rats. The kidneys of fetuses whose mother received a type 1 AII receptor (AT1) antagonist during gestation present several morphological alterations. Mutations in genes that encode components of the renin-angiotensin system are associated with autosomal recessive renal tubular dysgenesis. Morphological changes were detected in the kidneys of 3-week-old angiotensin-deficient mice. Mitogen-activated protein kinases (MAPKs) are important mediators that transduce extracellular stimuli to intracellular responses. The MAPK family comprises three major subgroups, namely extracellular signal-regulated protein kinase (ERK), c-jun N-terminal kinases (JNK), and p38 MAPK (p38). Important events in renal growth during nephrogenesis such as cellular proliferation and differentiation accompanied by apoptosis on a large scale can be mediated by MAPK pathways. A decrease in glomerulus number was observed in embryos cultured for 48 and 120 h with ERK or p38 inhibitors. Many effects of AII are mediated by MAPK pathways. Treatment with losartan during lactation provoked changes in renal function and structure associated with alterations in AT1 and type 2 AII (AT2) receptors and p-JNK and p-p38 expression in the kidney. Several studies have shown that AII and MAPKs play an important role in renal development. However, the relationship between the effects of AII and MAPK activation on renal development is still unclear.

Ultrasound Stimulation of Different Dental Stem Cell Populations: Role of Mitogen-activated Protein Kinase Signaling.

PubMed

Gao, Qianhua; Walmsley, A Damien; Cooper, Paul R; Scheven, Ben A

2016-03-01

Mesenchymal stem cells (MSCs) from dental tissues may respond to low-intensity pulsed ultrasound (LIPUS) treatment, potentially providing a therapeutic approach to promoting dental tissue regeneration. This work aimed to compare LIPUS effects on the proliferation and MAPK signaling in MSCs from rodent dental pulp stem cells (DPSCs) compared with MSCs from periodontal ligament stem cells (PDLSCs) and bone marrow stem cells (BMSCs). Isolated MSCs were treated with 1-MHz LIPUS at an intensity of 250 or 750 mW/cm2 for 5 or 20 minutes. Cell proliferation was evaluated by 5-bromo-2-deoxyuridine (BrdU) staining after 24 hours of culture following a single LIPUS treatment. Specific ELISAs were used to determine the total and activated p38, ERK1/2, and JNK MAPK signaling proteins up to 4 hours after treatment. Selective MAPK inhibitors PD98059 (ERK1/2), SB203580 (p38), and SP600125 (JNK) were used to determine the role of activation of the particular MAPK pathways. The proliferation of all MSC types was significantly increased after LIPUS treatment. LIPUS at a 750-mW/cm2 dose induced the greatest effects on DPSCs. BMSC proliferation was stimulated in equal measures by both intensities, whereas 250 mW/cm2 LIPUS exposure exerted maximum effects on PDLSCs. ERK1/2 was activated immediately in DPSCs after treatment. Concomitantly, DPSC proliferation was specifically modulated by ERK1/2 inhibition, whereas p38 and JNK inhibition exerted no effects. In BMSCs, JNK MAPK signaling was LIPUS activated, and the increase in proliferation was blocked by specific inhibition of the JNK pathway. In PDLSCs, JNK MAPK signaling was activated immediately after LIPUS, whereas p-p38 MAPK increased significantly in these cells 4 hours after exposure. Correspondingly, JNK and p38 inhibition modulated LIPUS-stimulated PDLSC proliferation. LIPUS promoted MSC proliferation in an intensity and cell-specific dependent manner via activation of distinct MAPK pathways. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Insulin-Like Growth Factor 1 Receptor and p38 Mitogen-Activated Protein Kinase Signals Inversely Regulate Signal Transducer and Activator of Transcription 3 Activity to Control Human Dental Pulp Stem Cell Quiescence, Propagation, and Differentiation

PubMed Central

Vandomme, Jerome; Touil, Yasmine; Ostyn, Pauline; Olejnik, Cecile; Flamenco, Pilar; El Machhour, Raja; Segard, Pascaline; Masselot, Bernadette; Bailliez, Yves; Formstecher, Pierre

2014-01-01

Dental pulp stem cells (DPSCs) remain quiescent until activated in response to severe dental pulp damage. Once activated, they exit quiescence and enter regenerative odontogenesis, producing reparative dentin. The factors and signaling molecules that control the quiescence/activation and commitment to differentiation of human DPSCs are not known. In this study, we determined that the inhibition of insulin-like growth factor 1 receptor (IGF-1R) and p38 mitogen-activated protein kinase (p38 MAPK) signaling commonly activates DPSCs and promotes their exit from the G0 phase of the cell cycle as well as from the pyronin Ylow stem cell compartment. The inhibition of these two pathways, however, inversely determines DPSC fate. In contrast to p38 MAPK inhibitors, IGF-1R inhibitors enhance dental pulp cell sphere-forming capacity and reduce the cells' colony-forming capacity without inducing cell death. The inverse cellular changes initiated by IGF-1R and p38 MAPK inhibitors were accompanied by inverse changes in the levels of active signal transducer and activator of transcription 3 (STAT3) factor, inactive glycogen synthase kinase 3, and matrix extracellular phosphoglycoprotein, a marker of early odontoblast differentiation. Our data suggest that there is cross talk between the IGF-1R and p38 MAPK signaling pathways in DPSCs and that the signals provided by these pathways converge at STAT3 and inversely regulate its activity to maintain quiescence or to promote self-renewal and differentiation of the cells. We propose a working model that explains the possible interactions between IGF-1R and p38 MAPK at the molecular level and describes the cellular consequences of these interactions. This model may inspire further fundamental study and stimulate research on the clinical applications of DPSC in cellular therapy and tissue regeneration. PMID:24266654

Carbon monoxide protects rat lung transplants from ischemia-reperfusion injury via a mechanism involving p38 MAPK pathway.

PubMed

Kohmoto, J; Nakao, A; Stolz, D B; Kaizu, T; Tsung, A; Ikeda, A; Shimizu, H; Takahashi, T; Tomiyama, K; Sugimoto, R; Choi, A M K; Billiar, T R; Murase, N; McCurry, K R

2007-10-01

Carbon monoxide (CO) provides protection against oxidative stress via anti-inflammatory and cytoprotective actions. In this study, we tested the hypothesis that a low concentration of exogenous (inhaled) CO would protect transplanted lung grafts from cold ischemia-reperfusion injury via a mechanism involving the mitogen-activated protein kinase (MAPK) signaling pathway. Lewis rats underwent orthotopic syngeneic or allogeneic left lung transplantation with 6 h of cold static preservation. Exposure of donors and recipients (1 h before and then continuously post-transplant) to 250 ppm CO resulted in significant improvement in gas exchange, reduced leukocyte sequestration, preservation of parenchymal and endothelial cell ultrastructure and reduced inflammation compared to animals exposed to air. The beneficial effects of CO were associated with p38 MAPK phosphorylation and were significantly prevented by treatment with a p38 MAPK inhibitor, suggesting that CO's efficacy is at least partially mediated by activation of p38 MAPK. Furthermore, CO markedly suppressed inflammatory events in the contralateral naïve lung. This study demonstrates that perioperative exposure of donors and recipients to CO at a low concentration can impart potent anti-inflammatory and cytoprotective effects in a clinically relevant model of lung transplantation and support further evaluation for potential clinical use.

Regulation of Hippo signalling by p38 signalling

PubMed Central

Huang, Dashun; Li, Xiaojiao; Sun, Li; Huang, Ping; Ying, Hao; Wang, Hui; Wu, Jiarui; Song, Haiyun

2016-01-01

The Hippo signalling pathway has a crucial role in growth control during development, and its dysregulation contributes to tumorigenesis. Recent studies uncover multiple upstream regulatory inputs into Hippo signalling, which affects phosphorylation of the transcriptional coactivator Yki/YAP/TAZ by Wts/Lats. Here we identify the p38 mitogen-activated protein kinase (MAPK) pathway as a new upstream branch of the Hippo pathway. In Drosophila, overexpression of MAPKK gene licorne (lic), or MAPKKK gene Mekk1, promotes Yki activity and induces Hippo target gene expression. Loss-of-function studies show that lic regulates Hippo signalling in ovary follicle cells and in the wing disc. Epistasis analysis indicates that Mekk1 and lic affect Hippo signalling via p38b and wts. We further demonstrate that the Mekk1-Lic-p38b cascade inhibits Hippo signalling by promoting F-actin accumulation and Jub phosphorylation. In addition, p38 signalling modulates actin filaments and Hippo signalling in parallel to small GTPases Ras, Rac1, and Rho1. Lastly, we show that p38 signalling regulates Hippo signalling in mammalian cell lines. The Lic homologue MKK3 promotes nuclear localization of YAP via the actin cytoskeleton. Upregulation or downregulation of the p38 pathway regulates YAP-mediated transcription. Our work thus reveals a conserved crosstalk between the p38 MAPK pathway and the Hippo pathway in growth regulation. PMID:27402810

The p38 pathway, a major pleiotropic cascade that transduces stress and metastatic signals in endothelial cells

PubMed Central

Corre, Isabelle; Paris, François; Huot, Jacques

2017-01-01

By gating the traffic of molecules and cells across the vessel wall, endothelial cells play a central role in regulating cardiovascular functions and systemic homeostasis and in modulating pathophysiological processes such as inflammation and immunity. Accordingly, the loss of endothelial cell integrity is associated with pathological disorders that include atherosclerosis and cancer. The p38 mitogen-activated protein kinase (MAPK) cascades are major signaling pathways that regulate several functions of endothelial cells in response to exogenous and endogenous stimuli including growth factors, stress and cytokines. The p38 MAPK family contains four isoforms p38α, p38β, p38γ and p38δ that are encoded by four different genes. They are all widely expressed although to different levels in almost all human tissues. p38α/MAPK14, that is ubiquitously expressed is the prototype member of the family and is referred here as p38. It regulates the production of inflammatory mediators, and controls cell proliferation, differentiation, migration and survival. Its activation in endothelial cells leads to actin remodeling, angiogenesis, DNA damage response and thereby has major impact on cardiovascular homeostasis, and on cancer progression. In this manuscript, we review the biology of p38 in regulating endothelial functions especially in response to oxidative stress and during the metastatic process. PMID:28903453

TCDD and omeprazole prime platelets through the aryl hydrocarbon receptor (AhR) non-genomic pathway.

PubMed

Pombo, Mónica; Lamé, Michael W; Walker, Naomi J; Huynh, Danh H; Tablin, Fern

2015-05-19

The role of the aryl hydrocarbon receptor (AhR) in hemostasis has recently gained increased attention. Here, we demonstrate, by qRT-PCR and western blot, that human platelets express both AhR mRNA and AhR protein. AhR protein levels increase in a dose dependent manner when incubated with either 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or omeprazole. Treatment of platelets with puromycin blocks increased AhR protein synthesis in the presence of AhR activators. Additionally, treatment of platelets with either activator results in phosphorylation of p38MAPK and cPLA2, two key signaling molecules in platelet activation pathways. Using the AhR competitive inhibitors alpha naphthoflavone and CH-223191, we show that phosphorylation of p38MAPK is AhR dependent. Further, inhibition of p38MAPK blocks downstream cPLA2 phosphorylation induced by TCDD or omeprazole. Treatment with AhR activators results in platelet priming, as demonstrated by increased platelet aggregation, which is inhibited by AhR antagonists. Our data support a model of the platelet AhR non-genomic pathway in which treatment with AhR activators results in increased expression of the AhR, phosphorylation of p38MAPK and cPLA2, leading to platelet priming in response to agonist. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A stable aspirin-triggered lipoxin A4 analog blocks phosphorylation of leukocyte-specific protein 1 in human neutrophils.

PubMed

Ohira, Taisuke; Bannenberg, Gerard; Arita, Makoto; Takahashi, Minoru; Ge, Qingyuan; Van Dyke, Thomas E; Stahl, Gregory L; Serhan, Charles N; Badwey, John A

2004-08-01

Lipoxins and their aspirin-triggered 15-epimers are endogenous anti-inflammatory agents that block neutrophil chemotaxis in vitro and inhibit neutrophil influx in several models of acute inflammation. In this study, we examined the effects of 15-epi-16-(p-fluoro)-phenoxy-lipoxin A(4) methyl ester, an aspirin-triggered lipoxin A(4)-stable analog (ATLa), on the protein phosphorylation pattern of human neutrophils. Neutrophils stimulated with the chemoattractant fMLP were found to exhibit intense phosphorylation of a 55-kDa protein that was blocked by ATLa (10-50 nM). This 55-kDa protein was identified as leukocyte-specific protein 1, a downstream component of the p38-MAPK cascade in neutrophils, by mass spectrometry, Western blotting, and immunoprecipitation experiments. ATLa (50 nM) also reduced phosphorylation/activation of several components of the p38-MAPK pathway in these cells (MAPK kinase 3/MAPK kinase 6, p38-MAPK, MAPK-activated protein kinase-2). These results indicate that ATLa exerts its anti-inflammatory effects, at least in part, by blocking activation of the p38-MAPK cascade in neutrophils, which is known to promote chemotaxis and other proinflammatory responses by these cells.

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.

Osthole Attenuates Hepatic Injury in a Rodent Model of Trauma-Hemorrhage

PubMed Central

Yu, Huang-Ping; Liu, Fu-Chao; Tsai, Yung-Fong; Hwang, Tsong-Long

2013-01-01

Recent evidences show that osthole possesses anti-inflammatory properties and protective effects following shock-like states, but the mechanism of these effects remains unknown. The p38 mitogen-activated protein kinase (p38 MAPK) pathway exerts anti-inflammatory effects in injury. The aim of this study was to investigate whether p38 MAPK plays any role in the osthole-mediated attenuation of hepatic injury after trauma-hemorrhage. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure maintained at approximately 35–40 mmHg for 90 minutes), followed by fluid resuscitation. During resuscitation, a single dose of osthole (3 mg/kg, intravenously) with and without a p38 MAPK inhibitor SB-203580 (2 mg/kg, intravenously), SB-203580 or vehicle was administered. Plasma alanine aminotransferase (ALT) with aspartate aminotransferase (AST) concentrations and various hepatic parameters were measured (n = 8 rats/group) at 24 hours after resuscitation. The results showed that trauma-hemorrhage increased hepatic myeloperoxidase activity, intercellular adhesion molecule-1 and interleukin-6 levels, and plasma ALT and AST concentrations. These parameters were significantly improved in the osthole-treated rats subjected to trauma-hemorrhage. Osthole treatment also increased hepatic phospho-p38 MAPK expression compared with vehicle-treated trauma-hemorrhaged rats. Co-administration of SB-203580 with osthole abolished the osthole-induced beneficial effects on the above parameters and hepatic injury. These results suggest that the protective effect of osthole administration on alleviation of hepatic injury after trauma-hemorrhage, which is, at least in part, through p38 MAPK-dependent pathway. PMID:23755293

p38 mitogen-activated protein kinase is involved in arginase-II-mediated eNOS-Uncoupling in Obesity

PubMed Central

2014-01-01

Background Endothelial nitric oxide synthase (eNOS)-uncoupling links obesity-associated insulin resistance and type-II diabetes to the increased incidence of cardiovascular disease. Studies have indicated that increased arginase is involved in eNOS-uncoupling through competing with the substrate L-arginine. Given that arginase-II (Arg-II) exerts some of its biological functions through crosstalk with signal transduction pathways, and that p38 mitogen-activated protein kinase (p38mapk) is involved in eNOS-uncoupling, we investigated here whether p38mapk is involved in Arg-II-mediated eNOS-uncoupling in a high fat diet (HFD)-induced obesity mouse model. Methods Obesity was induced in wild type (WT) and Arg-II-deficient (Arg-II-/-) mice on C57BL/6 J background by high-fat diet (HFD, 55% fat) for 14 weeks starting from age of 7 weeks. The entire aortas were isolated and subjected to 1) immunoblotting analysis of the protein level of eNOS, Arg-II and p38mapk activation; 2) arginase activity assay; 3) endothelium-dependent and independent vasomotor responses; 4) en face staining of superoxide anion and NO production with Dihydroethidium and 4,5-Diaminofluorescein Diacetate, respectively, to assess eNOS-uncoupling. To evaluate the role of p38mapk, isolated aortas were treated with p38mapk inhibitor SB203580 (10 μmol/L, 1 h) prior to the analysis. In addition, the role of p38mapk in Arg-II-induced eNOS-uncoupling was investigated in cultured human endothelial cells overexpressing Arg-II in the absence or presence of shRNA against p38mapk. Results HFD enhanced Arg-II expression/activity and p38mapk activity, which was associated with eNOS-uncoupling as revealed by decreased NO and enhanced L-NAME-inhibitable superoxide in aortas of WT obese mice. In accordance, WT obese mice revealed decreased endothelium-dependent relaxations to acetylcholine despite of higher eNOS protein level, whereas Arg-II-/- obese mice were protected from HFD-induced eNOS-uncoupling and endothelial dysfunction, which was associated with reduced p38mapk activation in aortas of the Arg-II-/- obese mice. Moreover, overexpression of Arg-II in human endothelial cells caused eNOS-uncoupling and augmented p38mapk activation. The Arg-II-induced eNOS-uncoupling was prevented by silencing p38mapk. Furthermore, pharmacological inhibition of p38mapk recouples eNOS in isolated aortas from WT obese mice. Conclusions Taking together, we demonstrate here for the first time that Arg-II causes eNOS-uncoupling through activation of p38 mapk in HFD-induced obesity. PMID:25034973

Carprofen Induction of p75NTR Dependent Apoptosis via the p38 MAPK Pathway in Prostate Cancer Cells

PubMed Central

Khwaja, Fatima S.; Quann, Emily J.; Pattabiraman, Nagarajan; Wynne, Shehla; Djakiew, Daniel

2008-01-01

The p75NTR functions as a tumor suppressor in prostate epithelial cells, where its expression declines with progression to malignant cancer. Previously, we demonstrated that treatment with R-flurbiprofen or ibuprofen induced p75NTR expression in several prostate cancer cell lines leading to p75NTR mediated decreased survival. Utilizing the 2-phenyl propionic acid moiety of these profens as a pharmacophore, we screened an in silico data base of 30 million compounds and identified carprofen as having an order of magnitude greater activity for induction of p75NTR levels and inhibition of cell survival. Prostate (PC-3, DU-145) and bladder (T24) cancer cells were more sensitive to carprofen induction of p75NTR associated loss of survival than breast (MCF7) and fibroblast (3T3) cells. Transfection of prostate cell lines with a dominant negative form of p75NTR prior to carprofen treatment partially rescued cell survival demonstrating a cause and effect relationship between carprofen induction of p75NTR levels and inhibition of survival. Carprofen induced apoptotic nuclear fragmentation in prostate but not in MCF7 and 3T3 cells. Furthermore, siRNA knockdown of the p38 MAPK protein prevented induction of p75NTR by carprofen in both prostate cell lines. Carprofen treatment induced phosphorylation of p38 MAPK as early as within 1 minute. Expression of a dominant negative form of MK2, the kinase downstream of p38 MAPK frequently associated with signaling cascades leading to apoptosis, prevented carprofen induction of the p75NTR protein. Collectively, we identify carprofen as a highly potent profen capable of inducing p75NTR dependent apoptosis via the p38 MAPK pathway in prostate cancer cells. PMID:18974393

The p38α mitogen-activated protein kinase as a central nervous system drug discovery target

PubMed Central

Borders, Aaron S; de Almeida, Lucia; Van Eldik, Linda J; Watterson, D Martin

2008-01-01

Protein kinases are critical modulators of a variety of cellular signal transduction pathways, and abnormal phosphorylation events can be a cause or contributor to disease progression in a variety of disorders. This has led to the emergence of protein kinases as an important new class of drug targets for small molecule therapeutics. A serine/threonine protein kinase, p38α mitogen-activated protein kinase (MAPK), is an established therapeutic target for peripheral inflammatory disorders because of its critical role in regulation of proinflammatory cytokine production. There is increasing evidence that p38α MAPK is also an important regulator of proinflammatory cytokine levels in the central nervous system, raising the possibility that the kinase may be a drug discovery target for central nervous system disorders where cytokine overproduction contributes to disease progression. Development of bioavailable, central nervous system-penetrant p38α MAPK inhibitors provides the required foundation for drug discovery campaigns targeting p38α MAPK in neurodegenerative disorders. PMID:19090985

The p38alpha mitogen-activated protein kinase as a central nervous system drug discovery target.

PubMed

Borders, Aaron S; de Almeida, Lucia; Van Eldik, Linda J; Watterson, D Martin

2008-12-03

Protein kinases are critical modulators of a variety of cellular signal transduction pathways, and abnormal phosphorylation events can be a cause or contributor to disease progression in a variety of disorders. This has led to the emergence of protein kinases as an important new class of drug targets for small molecule therapeutics. A serine/threonine protein kinase, p38alpha mitogen-activated protein kinase (MAPK), is an established therapeutic target for peripheral inflammatory disorders because of its critical role in regulation of proinflammatory cytokine production. There is increasing evidence that p38alpha MAPK is also an important regulator of proinflammatory cytokine levels in the central nervous system, raising the possibility that the kinase may be a drug discovery target for central nervous system disorders where cytokine overproduction contributes to disease progression. Development of bioavailable, central nervous system-penetrant p38alpha MAPK inhibitors provides the required foundation for drug discovery campaigns targeting p38alpha MAPK in neurodegenerative disorders.

Inhibition of p38 MAPK enhances ABT-737-induced cell death in melanoma cell lines: novel regulation of PUMA.

PubMed

Keuling, Angela M; Andrew, Susan E; Tron, Victor A

2010-06-01

The mitogen-activated protein kinase (MAPK) pathway is constitutively activated in the majority of melanomas, promoting cell survival, proliferation and migration. In addition, anti-apoptotic Bcl-2 family proteins Mcl-1, Bcl-xL and Bcl-2 are frequently overexpressed, contributing to melanoma's well-documented chemoresistance. Recently, it was reported that the combination of MAPK pathway inhibition by specific MEK inhibitors and Bcl-2 family inhibition by BH3-mimetic ABT-737 synergistically induces apoptotic cell death in melanoma cell lines. Here we provide the first evidence that inhibition of another key MAPK, p38, synergistically induces apoptosis in melanoma cells in combination with ABT-737. We also provide novel mechanistic data demonstrating that inhibition of p38 increases expression of pro-apoptotic Bcl-2 protein PUMA. Furthermore, we demonstrate that PUMA can be cleaved by a caspase-dependent mechanism during apoptosis and identify what appears to be the PUMA cleavage product. Thus, our findings suggest that the combination of ABT-737 and inhibition of p38 is a promising, new treatment strategy that acts through a novel PUMA-dependent mechanism.

Alpinia oxyphylla Miquel fruit extract activates MAPK-mediated signaling of PAs and MMP2/9 to induce Schwann cell migration and nerve regeneration.

PubMed

Chang, Yung-Ming; Ye, Chi-Xin; Ho, Tsung-Jung; Tsai, Te-Neng; Chiu, Ping-Ling; Tsai, Chin-Chuan; Lin, Yueh-Min; Kuo, Chia-Hua; Tsai, Fuu-Jen; Tsai, Chang-Hai; Huang, Chih-Yang

2014-05-01

This study investigates the molecular mechanisms by which Alpiniae oxyphyllae fructus (AOF) promotes neuron regeneration. A piece of silicone rubber was guided across a 15 mm gap in the sciatic nerve of a rat. This nerve gap was then filled with different concentrations of AOF extract (0-200 mg/ml). We investigated the role of MAPK (ERK1/2, JNK and p38) pathways for AOF-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in RSC96 Schwann cells. The results showed that AOF increased the expressions of uPA, tPA, MMP-9, and MAPKs in vivo. In vitro, our results show that treatment with AOF extract induces ERK1/2, JNK, and p38 phosphorylation to activate the downstream PAs and MMPs signaling expression. AOF-stimulated ERK1/2, JNK, and p38 phosphorylation attenuated by individual pretreatment with siRNAs or inhibitors (U0126, SP600125 and SB203580), resulting in migration and uPA-related signal pathway inhibition. Taken together our data suggests the MAPKs (ERK1/2, JNK and p38), PAs (uPA, tPA), MMP (MMP2, MMP9) regenerative and migration signaling pathway of Schwann cells regulated by AOF extract might play a major role in Schwann cell migration and damaged peripheral nerve regeneration.

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

PubMed

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

2015-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2014-03-01

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

Distinctive effects of eicosapentaenoic and docosahexaenoic acids in regulating neural stem cell fate are mediated via endocannabinoid signalling pathways.

PubMed

Dyall, S C; Mandhair, H K; Fincham, R E A; Kerr, D M; Roche, M; Molina-Holgado, F

2016-08-01

Emerging evidence suggests a complex interplay between the endocannabinoid system, omega-3 fatty acids and the immune system in the promotion of brain self-repair. However, it is unknown if all omega-3 fatty acids elicit similar effects on adult neurogenesis and if such effects are mediated or regulated by interactions with the endocannabinoid system. This study investigated the effects of DHA and EPA on neural stem cell (NSC) fate and the role of the endocannabinoid signalling pathways in these effects. EPA, but not DHA, significantly increased proliferation of NSCs compared to controls, an effect associated with enhanced levels of the endocannabinoid 2-arachidonylglycerol (2-AG) and p-p38 MAPK, effects attenuated by pre-treatment with CB1 (AM251) or CB2 (AM630) receptor antagonists. Furthermore, in NSCs derived from IL-1β deficient mice, EPA significantly decreased proliferation and p-p38 MAPK levels compared to controls, suggesting a key role for IL-1β signalling in the effects observed. Although DHA similarly increased 2-AG levels in wild-type NSCs, there was no concomitant increase in proliferation or p-p38 MAPK activity. In addition, in NSCs from IL-1β deficient mice, DHA significantly increased proliferation without effects on p-P38 MAPK, suggesting effects of DHA are mediated via alternative signalling pathways. These results provide crucial new insights into the divergent effects of EPA and DHA in regulating NSC proliferation and the pathways involved, and highlight the therapeutic potential of their interplay with endocannabinoid signalling in brain repair. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Downstream components of RhoA required for signal pathway of superoxide formation during phagocytosis of serum opsonized zymosans in macrophages.

PubMed

Kim, Jun Sub; Kim, Jae Gyu; Jeon, Chan Young; Won, Ha Young; Moon, Mi Young; Seo, Ji Yeon; Kim, Jong Il; Kim, Jaebong; Lee, Jae Yong; Choi, Soo Young; Park, Jinseu; Yoon Park, Jung Han; Ha, Kwon Soo; Kim, Pyeung Hyeun; Park, Jae Bong

2005-12-31

Rac1 and Rac2 are essential for the control of oxidative burst catalyzed by NADPH oxidase. It was also documented that Rho is associated with the superoxide burst reaction during phagocytosis of serum- (SOZ) and IgG-opsonized zymosan particles (IOZ). In this study, we attempted to reveal the signal pathway components in the superoxide formation regulated by Rho GTPase. Tat-C3 blocked superoxide production, suggesting that RhoA is essentially involved in superoxide formation during phagocytosis of SOZ. Conversely SOZ activated both RhoA and Rac1/2. Inhibition of RhoA-activated kinase (ROCK), an important downstream effector of RhoA, by Y27632 and myosin light chain kinase (MLCK) by ML-7 abrogated superoxide production by SOZ. Extracellular signaling-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) were activated during phagocytosis of SOZ, and Tat-C3 and SB203580 reduced ERK1/2 and p38 MAPK activation, suggesting that RhoA and p38 MAPK may be upstream regulators of ERK1/2. Inhibition of ERK1/2, p38 MAPK, phosphatidyl inositol 3-kinase did not block translocation of RhoA to membranes, suggesting that RhoA is upstream to these kinases. Inhibition of RhoA by Tat-C3 blocked phosphorylation of p47(PHOX). Taken together, RhoA, ROCK, p38MAPK, ERK1/2, and p47(PHOX) may be subsequently activated, leading to activation of NADPH oxidase to produce superoxide.

The p38 mitogen activated protein kinase regulates β-amyloid protein internalization through the α7 nicotinic acetylcholine receptor in mouse brain.

PubMed

Ma, Kai-Ge; Lv, Jia; Yang, Wei-Na; Chang, Ke-Wei; Hu, Xiao-Dan; Shi, Li-Li; Zhai, Wan-Ying; Zong, Hang-Fan; Qian, Yi-Hua

2018-03-01

Alzheimer's disease (AD) is one of the most devastating neurodegenerative disorders. Intracellular β-amyloid protein (Aβ) is an early event in AD. It induces the formation of amyloid plaques and neuron damage. The α7 nicotinic acetylcholine receptor (α7nAChR) has been suggested to play an important role in Aβ caused cognition. It has high affinity with Aβ and could mediate Aβ internalization in vitro. However, whether in mouse brain the p38 MAPK signaling pathway is involved in the regulation of the α7nAChR mediated Aβ internalization and their role in mitochondria remains little known. Therefore, in this study, we revealed that Aβ is internalized by cholinergic and GABAergic neurons. The internalized Aβ were found deposits in lysosomes/endosomes and mitochondria. Aβ could form Aβ-α7nAChR complex with α7nAChR, activates the p38 mitogen activated protein kinase (MAPK). And the increasing of α7nAChR could in return mediate Aβ internalization in the cortex and hippocampus. In addition, by using the α7nAChR agonist PNU282987, the p38 phosphorylation level decreases, rescues the biochemical changes which are tightly associated with Aβ-induced apoptosis, such as Bcl2/Bax level, cytochrome c (Cyt c) release. Collectively, the p38 MAPK signaling pathway could regulate the α7nAChR-mediated internalization of Aβ. The activation of α7nAChR or the inhibition of p38 MAPK signaling pathway may be a beneficial therapy to AD. Copyright © 2017 Elsevier Inc. All rights reserved.

Regulation of Hippo signalling by p38 signalling.

PubMed

Huang, Dashun; Li, Xiaojiao; Sun, Li; Huang, Ping; Ying, Hao; Wang, Hui; Wu, Jiarui; Song, Haiyun

2016-08-01

The Hippo signalling pathway has a crucial role in growth control during development, and its dysregulation contributes to tumorigenesis. Recent studies uncover multiple upstream regulatory inputs into Hippo signalling, which affects phosphorylation of the transcriptional coactivator Yki/YAP/TAZ by Wts/Lats. Here we identify the p38 mitogen-activated protein kinase (MAPK) pathway as a new upstream branch of the Hippo pathway. In Drosophila, overexpression of MAPKK gene licorne (lic), or MAPKKK gene Mekk1, promotes Yki activity and induces Hippo target gene expression. Loss-of-function studies show that lic regulates Hippo signalling in ovary follicle cells and in the wing disc. Epistasis analysis indicates that Mekk1 and lic affect Hippo signalling via p38b and wts We further demonstrate that the Mekk1-Lic-p38b cascade inhibits Hippo signalling by promoting F-actin accumulation and Jub phosphorylation. In addition, p38 signalling modulates actin filaments and Hippo signalling in parallel to small GTPases Ras, Rac1, and Rho1. Lastly, we show that p38 signalling regulates Hippo signalling in mammalian cell lines. The Lic homologue MKK3 promotes nuclear localization of YAP via the actin cytoskeleton. Upregulation or downregulation of the p38 pathway regulates YAP-mediated transcription. Our work thus reveals a conserved crosstalk between the p38 MAPK pathway and the Hippo pathway in growth regulation. © The Author (2016). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS.

Rat mesothelioma cell proliferation requires p38δ mitogen activated protein kinase and C/EBP-α.

PubMed

Zhong, Jun; Lardinois, Didier; Szilard, John; Tamm, Michael; Roth, Michael

2011-08-01

Pleural malignant mesothelioma is a rare but deadly tumour mainly induced by asbestos inhalation. Despite the ban of asbestos in 1990 in 52 countries, mesothelioma cases still increase worldwide. In pleural mesothelioma, p38 mitogen activated protein kinases (MAPK) have been suggested to play a major role in carcinogenesis and aggressiveness of tumours. The aim of this study was to determine the role of the different four p38 MAPK isoforms and their effect on proliferation together with the underlying signalling pathways in a rat pleural mesothelioma cell line. Rat pleural mesothelioma cells were stimulated with platelet-derived growth factor (PDGF)-BB and/or transforming growth factor beta (TGF)-β. MAPK and transcription factor expression and activation was monitored in the cytosol and nucleus by immuno-blotting. Proliferation was determined by manual cell count and siRNAs were used to control MAPK and transcription factor expression and action. Only PDGF-BB, but not TGF-β1 induced proliferation via activated Erk1/2 and p38 MAPK. The p38α and δ isoforms were expressed in the cytosol, and upon activation p38δ translocated into the nucleus, while p38α remained in the cytosol. No other p38 isoform was expressed by rat mesothelioma cells. C/EBP-α was found in both the cytosol and the nucleus, while C/EBP-β was not expressed at all. PDGF-BB induced proliferation was suppressed by down-regulation of either Erk1/2, or p38δ MAPK, or C/EBP-α. Furthermore, TGF-β inhibited PDGF-BB induced proliferation by interruption of p38 MAPK signalling. From this rat model, we conclude that in pleural mesothelioma, p38δ in C/EBP-α mediate proliferation and thus may represent new targets in mesothelioma therapy. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Human Th17 Migration in Three-Dimensional Collagen Involves p38 MAPK.

PubMed

Kadiri, Maleck; El Azreq, Mohammed-Amine; Berrazouane, Sofiane; Boisvert, Marc; Aoudjit, Fawzi

2017-09-01

T cell migration across extracellular matrix (ECM) is an important step of the adaptive immune response but is also involved in the development of inflammatory autoimmune diseases. Currently, the molecular mechanisms regulating the motility of effector T cells in ECM are not fully understood. Activation of p38 MAPK has been implicated in T cell activation and is critical to the development of immune and inflammatory responses. In this study, we examined the implication of p38 MAPK in regulating the migration of human Th17 cells through collagen. Using specific inhibitor and siRNA, we found that p38 is necessary for human Th17 migration in three-dimensional (3D) collagen and that 3D collagen increases p38 phosphorylation. We also provide evidence that the collagen receptor, discoidin domain receptor 1 (DDR1), which promotes Th17 migration in 3D collagen, is involved in p38 activation. Together, our findings suggest that targeting DDR1/p38 MAPK pathway could be beneficial for the treatment of Th17-mediated inflammatory diseases. J. Cell. Biochem. 118: 2819-2827, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

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.

p38 mitogen-activated protein kinase-induced nuclear factor kappa-light-chain-enhancer of activated B cell activity is required for neuroprotection in retinal ischemia/reperfusion injury.

PubMed

Jiang, Shao-Yun; Zou, Yuan-Yuan; Wang, Jian-Tao

2012-01-01

In our previous study, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) played a neuroprotective role in retinal ischemia/reperfusion (I/R) injury in rats. However, the mechanism of NF-κB neuroprotection is still unclear. We hypothesize that p38 mitogen-activated protein kinase (MAPK) is expressed and NF-κB activity induced by p38 MAPK plays a neuroprotective role through antiapoptotic genes (B-cell lymphoma [Bcl]-2 and Bcl-XL) in retinal cells in retinal I/R injury. Retinal ischemia was induced by elevating intraocular pressure in rats. After retinal I/R, the p38 MAPK, NF-κB p65, Bcl-2, and Bcl-XL mRNA levels were measured with real-time polymerase chain reaction. NF-κB p65 activity was assessed with NF-κB enzyme-linked immunosorbent assay in retinal I/R injury and after application of the p38 MAPK inhibitor (SB203580). Furthermore, SB203580 and NF-κB p65 short interfering RNA (siRNA) were used in retinal I/R injury to examine the effects on Bcl-2 and Bcl-XL levels and nucleosome release in the retina and cell survival in the ganglion cell layer. The mRNA levels of NF-κB p65 and p38 MAPK reached a peak at 6 h after retinal I/R and then decreased gradually. The mRNA levels of Bcl-2 and Bcl-XL significantly increased at 2, 4, and 6 h, peaked at 8 h, and decreased gradually, but remained at a higher level compared with the normal control, which was accompanied by an increase in NF-κB p65 in nuclear extracts. After application of SB203580, the increase in the NF-κB p65 levels in the nucleus induced with I/R was completely abolished, and the mRNA expression of Bcl-2 and Bcl-XL decreased significantly compared with the I/R controls. In addition, NF-κB p65 siRNA inhibited Bcl-2 and Bcl-XL expression. Inhibition of the p38 MAPK-NF-κB pathway (using SB203580 or NF-κB p65 siRNA) increased retinal nucleosome release and decreased the number of ganglion cells. These findings provide evidence of crosstalk between p38 MAPK and NF-κB p65 and demonstrate a possible neuroprotective role for the p38 MAPK-NF-κB pathway through Bcl-2 and Bcl-XL in retinal I/R injury in rats.

p38 mitogen-activated protein kinase–induced nuclear factor kappa-light-chain-enhancer of activated B cell activity is required for neuroprotection in retinal ischemia/reperfusion injury

PubMed Central

Jiang, Shao-Yun; Zou, Yuan-Yuan

2012-01-01

Purpose In our previous study, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) played a neuroprotective role in retinal ischemia/reperfusion (I/R) injury in rats. However, the mechanism of NF-κB neuroprotection is still unclear. We hypothesize that p38 mitogen-activated protein kinase (MAPK) is expressed and NF-κB activity induced by p38 MAPK plays a neuroprotective role through antiapoptotic genes (B-cell lymphoma [Bcl]-2 and Bcl-XL) in retinal cells in retinal I/R injury. Methods Retinal ischemia was induced by elevating intraocular pressure in rats. After retinal I/R, the p38 MAPK, NF-κB p65, Bcl-2, and Bcl-XL mRNA levels were measured with real-time polymerase chain reaction. NF-κB p65 activity was assessed with NF-κB enzyme-linked immunosorbent assay in retinal I/R injury and after application of the p38 MAPK inhibitor (SB203580). Furthermore, SB203580 and NF-κB p65 short interfering RNA (siRNA) were used in retinal I/R injury to examine the effects on Bcl-2 and Bcl-XL levels and nucleosome release in the retina and cell survival in the ganglion cell layer. Results The mRNA levels of NF-κB p65 and p38 MAPK reached a peak at 6 h after retinal I/R and then decreased gradually. The mRNA levels of Bcl-2 and Bcl-XL significantly increased at 2, 4, and 6 h, peaked at 8 h, and decreased gradually, but remained at a higher level compared with the normal control, which was accompanied by an increase in NF-κB p65 in nuclear extracts. After application of SB203580, the increase in the NF-κB p65 levels in the nucleus induced with I/R was completely abolished, and the mRNA expression of Bcl-2 and Bcl-XL decreased significantly compared with the I/R controls. In addition, NF-κB p65 siRNA inhibited Bcl-2 and Bcl-XL expression. Inhibition of the p38 MAPK-NF-κB pathway (using SB203580 or NF-κB p65 siRNA) increased retinal nucleosome release and decreased the number of ganglion cells. Conclusions These findings provide evidence of crosstalk between p38 MAPK and NF-κB p65 and demonstrate a possible neuroprotective role for the p38 MAPK-NF-κB pathway through Bcl-2 and Bcl-XL in retinal I/R injury in rats. PMID:22876136

EphA2 modulates radiosensitive of hepatocellular carcinoma cells via p38/mitogen-activated protein kinase-mediated signal pathways.

PubMed

Jin, Qiao; Li, Xiangjun; Cao, Peiguo

2015-10-01

This experiment was conducted to investigate the role of EPH receptor A2 (EphA2) in the modulation of radiosensitivity of hepatic cellular cancer (HCC) cells and to determine whether p38/mitogen-activated protein kinase (p38MAPK) signaling mediated EphA2 function in this respect. The protein expressions of EphA2 and phosphorylated p38MAPK were tested in HCC and normal hepatic tissues. In HCC 97H cells, EphA2 was overexpressed and knocked out by transfection with EphA2 expression vector and EphA2-ShRNA, respectively, prior to cell exposure to low-dose irradiation. Significantly upregulated EphA2 and phosphorylated p38MAPK were observed in HCC tissues, compared with those in normal hepatic tissues. Low-dose irradiation (1 Gy) only caused minor damage to HCC 97H cells, as assessed by alterations in cell viability, apoptosis rate, and cell healing capacity (p = 0.072, p = 0.078, and p = 0.069 respectively). However, EphA2 knock-out in HCC 97H cells induced significant reduction in cell viability and cell healing capacity after these cells were subjected to low-dose irradiation. Apoptosis rate underwent dramatic increase (p < 0.01). By contrast, EphA2 overexpression in HCC 97H cells reversed these effects and enhanced cell colony formation rate, thus displaying remarkable attenuation of radiosensitivity of HCC 97H cells. Further, SB203580, a specific inhibitor of p38MAPK, was added to HCC 97H cells over-expressing EphA2. The effect of EphA2 overexpression on the radiosensitivity of HCC 97H cells was abrogated. Thus, the present study indicates that EphA2 have the ability to negatively regulate the radiosensitivity of HCC 97H cells, which mainly depends on 38MAPK-mediated signal pathways. Copyright © 2015. Published by Elsevier Taiwan.

Neuroprotective effects of ebselen in traumatic brain injury model: involvement of nitric oxide and p38 mitogen-activated protein kinase signalling pathway.

PubMed

Wei, Liang; Zhang, Yanfei; Yang, Cheng; Wang, Qi; Zhuang, Zhongwei; Sun, Zhiyang

2014-02-01

Previous investigations have found that ebselen is able to treat neurodegenerative diseases caused by radical and acute total cerebral ischaemia. The aim of the present study was to investigate the neuroprotective effects of ebselen in a traumatic brain injury (TBI) model. Ninety Sprague-Dawley rats were randomly divided into five groups (n = 18 in each): (i) sham operation; (ii) an injury model group; (iii) low-dose (3 mg/kg) ebselen-treated group; (iv) a moderate-dose (10 mg/kg) ebselen-treated group; and (v) a high-dose (30 mg/kg) ebselen-treated group. The TBI model was created according using a modified weight-drop model. Neurological severity score (NSS), brain water content and histopathological deficits were assessed as parameters of injury severity. Expression of nitric oxide (NO), inducible NO synthase (iNOS) mRNA, Toll-like receptor (TLR) and phosphorylated (p-) p38 mitogen-activated protein kinase (MAPK) were examined by chemical colorimetry, quantitative polymerase chain reaction and western blotting 24 h after intragastric ebselen administration. Rats in the TBI model group exhibited markedly more severe neurological injury (higher NSS, more brain water content and more histopathological deficits) than those in the sham-operated group. Ebselen treatment significantly ameliorated the neurological injury of TBI rats in a dose-dependent manner. Moreover, ebselen significantly reduced the NO and iNOS mRNA levels and inhibited TLR4 and p-p38 MAPK expression, indicating the involvement of NO and p38 MAPK signalling pathways in the neuroprotection afforded by ebselen. In conclusion, ebselen ameliorated neurological injury, possibly by reducing NO levels and modulating the TLR4-mediated p38 MAPK signalling pathway. Therefore, ebselen may have potential to treat secondary injuries of TBI. © 2013 Wiley Publishing Asia Pty Ltd.

Osmolarity affects matrix synthesis in the nucleus pulposus associated with the involvement of MAPK pathways: A study of ex vivo disc organ culture system.

PubMed

Li, Pei; Gan, Yibo; Xu, Yuan; Li, Songtao; Song, Lei; Li, Sukai; Li, Huijuan; Zhou, Qiang

2016-06-01

Matrix homeostasis within the nucleus pulposus (NP) is important for disc function. Unfortunately, the effects of osmolarity on NP matrix synthesis in a disc organ culture system and the underlying mechanisms are largely unknown. The present study was to investigate the effects of different osmolarity modes (constant and cyclic) and osmolarity levels (hypo-, iso-, and hyper-) on NP matrix synthesis using a disc organ culture system and determine whether ERK1/2 or p38MAPK pathway has a role in this process. Porcine discs were cultured for 7 days in various osmotic media, including constant hypo-, iso-, hyper-osmolarity (330, 430, and 550 mOsm/kg, respectively) and cyclic-osmolarity (430 mOsm/kg for 8 h, followed by 550 mOsm/kg for 16 h). The role of ERK1/2 and p38MAPK pathways were determined by their inhibitors U0126 and SB202190 respectively. The expression of SOX9 and downstream aggrecan and collagen II, biochemical content, and histology were used to assess NP matrix synthesis. The findings revealed that NP matrix synthesis was promoted in iso- and cyclic-osmolarity cultures compared to hypo- or hyper-osmolarity culture although the level of matrix synthesis in cyclic-osmolarity culture did not reach that in iso-osmolarity culture. Further analysis suggested that inhibition of the ERK1/2 or p38MAPK pathway in iso- and cyclic-osmolarity cultures reduced NP matrix production. Therefore, we concluded that the effects of osmolarity on NP matrix synthesis depend on osmolarity level (hypo-, iso-, or hyper-) and osmolarity mode (constant or cyclic), and the ERK1/2 and p38MAPK pathways may participate in this process. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1092-1100, 2016. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Serotonin disrupts esophageal mucosal integrity: an investigation using a stratified squamous epithelial model.

PubMed

Wu, Liping; Oshima, Tadayuki; Tomita, Toshihiko; Ohda, Yoshio; Fukui, Hirokazu; Watari, Jiro; Miwa, Hiroto

2016-11-01

Serotonin regulates gastrointestinal function, and mast cells are a potential nonneuronal source of serotonin in the esophagus. Tight junction (TJ) proteins in the esophageal epithelium contribute to the barrier function, and the serotonin signaling pathway may contribute to epithelial leakage in gastroesophageal reflux disease. Therefore, the aim of this study was to investigate the role of serotonin on barrier function, TJ proteins, and related signaling pathways. Normal primary human esophageal epithelial cells were cultured with use of an air-liquid interface system. Serotonin was added to the basolateral compartment, and transepithelial electrical resistance (TEER) was measured. The expression of TJ proteins and serotonin receptor 7 (5-HT 7 ) was assessed by Western blotting. The involvement of 5-HT 7 was assessed with use of an antagonist and an agonist. The underlying cellular signaling pathways were examined with use of specific blockers. Serotonin decreased TEER and reduced the expression of TJ proteins ZO-1, occludin, and claudin 1, but not claudin 4. A 5-HT 7 antagonist blocked the serotonin-induced decrease in TEER, and a 5-HT 7 agonist decreased TEER. Inhibition of p38 mitogen-activated protein kinase (MAPK) reduced the serotonin-induced decrease in TEER. Inhibition of p38 MAPK blocked the decrease of ZO-1 levels, whereas extracellular-signal-regulated kinase (ERK) inhibition blocked the decrease in occludin levels. Cell signaling pathway inhibitors had no effect on serotonin-induced alterations in claudin 1 and claudin 4 levels. Serotonin induced phosphorylation of p38 MAPK and ERK, and a 5-HT 7 antagonist partially blocked serotonin-induced phosphorylation of p38 MAPK but not that of ERK. Serotonin disrupted esophageal squamous epithelial barrier function by modulating the levels of TJ proteins. Serotonin signaling pathways may mediate the pathogenesis of gastroesophageal reflux disease.

Calcium alters monoamine oxidase-A parameters in human cerebellar and rat glial C6 cell extracts: possible influence by distinct signalling pathways.

PubMed

Cao, Xia; Li, Xin-Min; Mousseau, Darrell D

2009-07-31

Calcium (Ca(2+)) is known to augment monoamine oxidase-A (MAO-A) activity in cell cultures as well as in brain extracts from several species. This association between Ca(2+) and MAO-A could contribute to their respective roles in cytotoxicity. However, the effect of Ca(2+) on MAO-A function in human brain has as yet to be examined as does the contribution of specific signalling cascades. We examined the effects of Ca(2+) on MAO-A activity and on [(3)H]Ro 41-1049 binding to MAO-A in human cerebellar extracts, and compared this to its effects on MAO-A activity in glial C6 cells following the targeting of signalling pathways using specific chemical inhibitors. Ca(2+) enhances MAO-A activity as well as the association of [(3)H]Ro 41-1049 to MAO-A in human cerebellar extracts. The screening of neuronal and glial cell cultures reveals that MAO-A activity does not always correlate with the expression of either mao-A mRNA or MAO-A protein. Inhibition of the individual PI3K/Akt, ERK and p38(MAPK) signalling pathways in glial C6 cells all augment basal MAO-A activity. Inhibition of the p38(MAPK) pathway also augments Ca(2+)-sensitive MAO-A activity. We also observe the inverse relation between p38(MAPK) activation and MAO-A function in C6 cultures grown to full confluence. The Ca(2+)-sensitive component to MAO-A activity is present in human brain and in vitro studies link it to the p38(MAPK) pathway. This means of influencing MAO-A function could explain its role in pathologies as diverse as neurodegeneration and cancers.

The P38alpha and P38delta MAP kinases may be gene therapy targets in the future treatment of severe burns.

PubMed

Wang, Shuyun; Huang, Qiaobing; Guo, Xiaohua; Brunk, Ulf T; Han, Jiahuai; Zhao, Keseng; Zhao, Ming

2010-08-01

Microvascular barrier damage, induced by thermal injury, imposes life-threatening problems owing to the pathophysiological consequences of plasma loss and impaired perfusion that finally may lead to multiple organ failure. The aim of the present study was to define the signaling role of selected mitogen-activated protein kinases (MAPKs) in general vessel hyperpermeability caused by burns and to look for a potential gene therapy. Rearrangement of cytoskeletons and cell tight junctions were evaluated by phalloidin labeling of actin and immunocytochemical demonstration of the ZO-1 protein, whereas blood vessel permeability was evaluated by a fluorescence ratio technique. The p38 MAPK inhibitor SB203580 largely blocked burn serum-induced stress-fiber formation and tight-junction damage. Using the adenoviral approach to transfect dominant negative forms of p38 MAPKs, we found that p38alpha and p38delta had similar effects. The in vivo part of the study showed that transfection of these two constructs significantly lowered general venular hyperpermeability and enhanced the survival of burned animals. Because the p38 MAPK pathway seems to play a crucial role in burn-induced vascular hyperpermeability, general transfection with p38 MAP dominant negative constructs might become a new therapeutic method to block burn-induced plasma leakage.

p38β, A novel regulatory target of Pokemon in hepatic cells.

PubMed

Chen, Zhe; Liu, Feng; Zhang, Nannan; Cao, Deliang; Liu, Min; Tan, Ying; Jiang, Yuyang

2013-06-27

Pokemon is an important proto-oncogene involved in various biological processes and cancer development, such as cell differentiation, tumorigenesis and metastasis. Pokemon is recognized as a transcription factor localized upstream of several oncogenes, regulating their expression. p38MAPKs act as key regulatory factors in cellular signaling pathways associated with inflammatory responses, cell proliferation, differentiation and survival. p38β, a member of p38MAPK family, is closely correlated with tumorigenesis, but the mechanism of activation remains unclear. In this study, we found overexpression of Pokemon promoted the growth, migration and invasion of HepG2 cells. However, a p38 inhibitor SB202190 efficiently attenuated the promoting effect of Pokemon in the HepG2 cells. Targeted expression or silencing of Pokemon changed cellular p38β protein level and phosphorylation of downstream ATF2 in the p38 signaling pathway. Both dual luciferase report assay and ChIP assay suggested that p38β is a novel regulatory target of the transcription factor Pokemon and positively regulated by Pokemon in hepatic cells.

p38β, A Novel Regulatory Target of Pokemon in Hepatic Cells

PubMed Central

Chen, Zhe; Liu, Feng; Zhang, Nannan; Cao, Deliang; Liu, Min; Tan, Ying; Jiang, Yuyang

2013-01-01

Pokemon is an important proto-oncogene involved in various biological processes and cancer development, such as cell differentiation, tumorigenesis and metastasis. Pokemon is recognized as a transcription factor localized upstream of several oncogenes, regulating their expression. p38MAPKs act as key regulatory factors in cellular signaling pathways associated with inflammatory responses, cell proliferation, differentiation and survival. p38β, a member of p38MAPK family, is closely correlated with tumorigenesis, but the mechanism of activation remains unclear. In this study, we found overexpression of Pokemon promoted the growth, migration and invasion of HepG2 cells. However, a p38 inhibitor SB202190 efficiently attenuated the promoting effect of Pokemon in the HepG2 cells. Targeted expression or silencing of Pokemon changed cellular p38β protein level and phosphorylation of downstream ATF2 in the p38 signaling pathway. Both dual luciferase report assay and ChIP assay suggested that p38β is a novel regulatory target of the transcription factor Pokemon and positively regulated by Pokemon in hepatic cells. PMID:23807508

Infiltrating macrophages in diabetic nephropathy promote podocytes apoptosis via TNF-α-ROS-p38MAPK pathway

PubMed Central

Guo, Yinfeng; Song, Zhixia; Zhou, Min; Yang, Ying; Zhao, Yu; Liu, Bicheng; Zhang, Xiaoliang

2017-01-01

Macrophage infiltration has been linked to the pathogenesis of diabetic nephropathy (DN). However, how infiltrating macrophages affect the progression of DN is unknown. Although infiltrating macrophages produce pro-inflammatory mediators and induce apoptosis in a variety of target cells, there are no studies in podocytes. Therefore, we tested the contribution of macrophages to podocytes apoptosis in DN. in vivo experiments showed that apoptosis in podocytes was increased in streptozocin (STZ)-induced diabetic rats compared with control rats and that this apoptosis was accompanied by increased macrophages infiltration in the kidney. Then, we established a co-culture system to study the interaction between macrophages and podocytes in the absence or presence of high glucose. Macrophages did not trigger podocytes apoptosis when they were co-cultured in the absence of high glucose in a transwell co-culture system. Additionally, although podocyte apoptosis was increased after high glucose stimulation, there was a further enhancement of podocyte apoptosis when podocytes were co-cultured with macrophages in the presence of high glucose compared with podocytes cultured alone in high glucose. Mechanistically, we found that macrophages were activated when they were exposed to high glucose, displaying pro-inflammatory M1 polarization. Furthermore, conditioned media (CM) from such high glucose-activated M1 macrophages (HG-CM) trigged podocytes apoptosis in a reactive oxygen species (ROS)-p38mitogen-activated protein kinases (p38MAPK) dependent manner, which was abolished by either a ROS inhibitor (Tempo) or a p38MAPK inhibitor (SB203580). Finally, we identified tumor necrosis factor (TNF-α) as a key mediator of high glucose-activated macrophages to induce podocytes apoptosis because an anti-TNF-α neutralizing antibody blunted the apoptotic response, excess ROS generation and p38MPAK activation in podocytes induced by HG-CM. Moreover, addition of recombinant TNF-α similarly resulted in podocytes apoptosis. In summary, the TNF-α that was released by high glucose-activated macrophages promoted podocytes apoptosis via ROS-p38MAPK pathway. Blockade of TNF-α secretion from high glucose activated macrophages and ROS-p38MAPK pathway might be effective therapeutic options to limit podocytes apoptosis and delay the progression of diabetic nephropathy. PMID:28881810

Effects of cadmium on MAPK signalling pathways and HSP70 expression in a human trophoblast cell line.

PubMed

Valbonesi, P; Ricci, L; Franzellitti, S; Biondi, C; Fabbri, E

2008-08-01

The aim of this work was to provide a greater insight into the possible effects of Cd on signal transduction and stress-related pathways in reproductive tissues. Cd is a known placental toxin in both animals and humans. Our experiments were designed to study the influence of Cd on MAPK (ERK1/2, JNK1/2 and p38MAPK) activation in the extravillous trophoblast cell line, HTR-8/SVneo, used as an experimental model. We also studied the HSP70 response in cells exposed to Cd, since these proteins may have an important role in conferring protection and tolerance against teratogenic concentrations of the metal. The effects of Cd were compared with those of a well-known toxic agent, H2O2. The metal triggered MAPK activation in a dose- and time-dependent manner. At 30 microM Cd, stimulations of about 300%, 550% and 250% were observed for ERK1/2, JNK1/2, and p38MAPK, respectively. Phosphorylation of ERK1/2 and JNK1/2 was significantly induced after a 1-h exposure to 30 microM Cd, while that of p38MAPK occurred only after 8h. Similarly, H2O2 caused dose- and time-dependent activation of MAPK pathways. Cd potently stimulated HSP70 expression and that of related genes HSP70 A, B and C. H2O2 did not increase HSP70 and HSP70 A and B expression, while temporarily increasing HSP70C transcript levels. In conclusion, Cd triggers different stress responses in trophoblast cells involving HSP70 and SAPK, and also enhances ERK1/2 phosphorylation. Since MAPK dependent pathways play a crucial role during pregnancy, non-physiological activation by Cd exposure may disrupt normal functions in trophoblast cells.

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

PubMed Central

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

2015-01-01

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

Sex-specific control of CNS autoimmunity by p38 MAPK signaling in myeloid cells

PubMed Central

Krementsov, Dimitry N.; Noubade, Rajkumar; Dragon, Julie A.; Otsu, Kinya; Rincon, Mercedes; Teuscher, Cory

2013-01-01

Objective Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS), characterized by a global increasing incidence driven by relapsing-remitting disease in females. p38 MAP kinase (MAPK) has been described as a key regulator of inflammatory responses in autoimmunity, but its role in the sexual dimorphism in MS or MS models remains unexplored. Methods Toward this end, we used experimental autoimmune encephalomyelitis (EAE), the principal animal model of MS, combined with pharmacologic and genetic inhibition of p38 MAPK activity and transcriptomic analyses. Results Pharmacologic inhibition of p38 MAPK selectively ameliorated EAE in female mice. Conditional deletion studies demonstrated that p38α signaling in macrophages/myeloid cells, but not T cells or dendritic cells, recapitulated this sexual dimorphism. Analysis of CNS inflammatory infiltrates showed that female, but not male mice lacking p38α in myeloid cells exhibited reduced immune cell activation compared with controls, while peripheral T cell priming was unaffected in both sexes. Transcriptomic analyses of myeloid cells revealed differences in p38α-controlled transcripts comprising female- and male-specific gene modules, with greater p38α dependence of pro-inflammatory gene expression in females. Interpretation Our findings demonstrate a key role for p38α in myeloid cells in CNS autoimmunity and uncover important molecular mechanisms underlying sex differences in disease pathogenesis. Taken together, our results suggest that the p38 MAPK signaling pathway represents a novel target for much needed disease modifying therapies for MS. PMID:24027119

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Lina; Tao, Xufeng; Xu, Youwei

Oxidative stress is involved in hepatic stellate cells (HSCs) activation and extracellular matrix overproduction. We previously reported the promising effects of dioscin against CCl{sub 4}-induced liver fibrosis, but its effects and mechanisms on BDL- and DMN-induced liver fibrosis remain unknown. The results in the present study indicated that dioscin significantly inhibited HSCs activation and attenuated hepatic fibrosis in rats. Furthermore, dioscin markedly up-regulated the levels of sirtuin 1 (Sirt1), HO-1, GST, GCLC and GCLM via increasing the nuclear translocation of nuclear erythroid factor 2-related factor 2 (Nrf2), which in turn inhibited mitogen-activated protein kinase 14 (p38 MAPK) phosphorylation and reducedmore » the levels of COL1A1, COL3A1, α-SMA and fibronectin. These results were further validated by knockdown of Sirt1 and Nrf2 using siRNAs silencing, and abrogation of p38 MAPK using SB-203580 (a p38 MAPK inhibitor) in HSC-T6 and LX-2 cells. Collectively, our findings confirmed the potent effects of dioscin against liver fibrosis and also provided novel insights into the mechanisms of this compound as a candidate for the prevention of liver fibrosis in the future. - Highlights: • Dioscin showed potent effects against BDL- and DMN-induced liver fibrosis in rats. • Dioscin significantly suppressed oxidative stress. • Dioscin triggered Sirt1/Nrf2-mediated inhibition of p38 MAPK pathway. • Dioscin should be developed as a novel candidate to treat liver fibrosis.« less

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.

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

Hindlimb unweighting induces changes in the p38MAPK contractile pathway of the rat abdominal aorta.

PubMed

Summers, Scott Matthew; Hayashi, Yuichiro; Nguyen, Steven Vu; Nguyen, Thu Minh; Purdy, Ralph Earl

2009-07-01

Hindlimb unweighting (HLU) of rats is a model used to mimic the cephalic fluid shift potentially involved in the orthostatic intolerance experienced by astronauts. Certain arteries in these rats exhibit a decreased contractile response to adrenergic agonists. It was shown previously that this may be caused by changes in thick filament regulation (Summers et al., Vascul Pharmacol 48: 208-214, 2008). In the present study, it was hypothesized that HLU also modifies thin filament regulation by effects on p38(MAPK) and ERK. Abdominal aorta rings from 20-day HLU rats and untreated controls were subjected to phenylephrine and phorbol 12,13-dibutyrate (PDBU) concentration response curves in the presence and absence of two inhibitors: the p38(MAPK) inhibitor SB-203580 and the MEK inhibitor U-0126. SB-203580 decreased control sensitivity to both agonists, but HLU sensitivity was not significantly affected. U-0126, which blocks enzymes immediately upstream of ERK, affected sensitivity to both agonists equally between control and HLU. Western blot analysis revealed no change in total levels of p38(MAPK) and its downstream target heat shock protein 27 but did reveal a decrease in phosphorylated levels of both after stimulation with PDBU and phenylephrine after HLU treatment. Neither total ERK nor phosphorylated levels after stimulation were affected by HLU. Total levels of caldesmon, a molecule downstream of both pathways, were decreased, but phosphorylated levels after stimulation were decreased by roughly twice as much. The results of this study demonstrate that HLU downregulates p38(MAPK), but not ERK, signaling. In turn, this may decrease actin availability for contraction.

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.

IL-12 and IL-23 Production in Toxoplasma gondii- or LPS-Treated Jurkat T Cells via PI3K and MAPK Signaling Pathways.

PubMed

Ismail, Hassan Ahmed Hassan Ahmed; Kang, Byung-Hun; Kim, Jae-Su; Lee, Jae-Hyung; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min; Lee, Young-Ha

2017-12-01

IL-12 and IL-23 are closely related in structure, and have been shown to play crucial roles in regulation of immune responses. However, little is known about the regulation of these cytokines in T cells. Here, we investigated the roles of PI3K and MAPK pathways in IL-12 and IL-23 production in human Jurkat T cells in response to Toxoplasma gondii and LPS. IL-12 and IL-23 production was significantly increased in T cells after stimulation with T. gondii or LPS. T. gondii and LPS increased the phosphorylation of AKT, ERK1/2, p38 MAPK, and JNK1/2 in T cells from 10 min post-stimulation, and peaked at 30-60 min. Inhibition of the PI3K pathway reduced IL-12 and IL-23 production in T. gondii-infected cells, but increased in LPS-stimulated cells. IL-12 and IL-23 production was significantly reduced by ERK1/2 and p38 MAPK inhibitors in T. gondii- and LPS-stimulated cells, but not in cells treated with a JNK1/2 inhibitor. Collectively, IL-12 and IL-23 production was positively regulated by PI3K and JNK1/2 in T. gondii-infected Jurkat cells, but negatively regulated in LPS-stimulated cells. And ERK1/2 and p38 MAPK positively regulated IL-12 and IL-23 production in Jurkat T cells. These data indicate that T. gondii and LPS induced IL-12 and IL-23 production in Jurkat T cells through the regulation of the PI3K and MAPK pathways; however, the mechanism underlying the stimulation of IL-12 and IL-23 production by T. gondii in Jurkat T cells is different from that of LPS.

Involvement of the MAPK pathway in the pressure-induced synovial metaplasia procedure for the temporomandibular joint.

PubMed

Wu, M J; Lu, H P; Gu, Z Y; Zhou, Y Q

2016-06-20

Abnormal pressure is an important factor that contributes to bone adaptation in the temporomandibular joint (TMJ). We determined the effect of the mitogen-activated protein kinases (MAPK) pathway on the pressure-induced synovial metaplasia procedure for the TMJ, both in vitro and in vivo. Synovial fibroblasts (SFs) were exacted from rat TMJs and exposed to different hydrostatic pressures. The protein extracts were analyzed to determine the activation of ERK1/2, JNK, and p38. Surgical anterior disc displacement (ADD) was also performed on Japanese rabbits, and the proteins of TMJ were isolated to analyze pressure-induced MAPK activation after 1, 2, 4, and 8 weeks. The results showed that the activation of ERK1/2 and JNK in SFs significantly changed with increasing hydrostatic pressure, whereas p38 activation did not change. Moreover, p38 was activated in animals 1 week after surgical ADD. The levels of p38 gradually increased after 2 and 4 weeks, and then slightly decreased but remained higher than in the control 8 weeks after surgical ADD. Nevertheless, JNK was rarely activated after the ADD treatment. Our findings suggest the involvement of MAPK activation in the pressure-induced synovial metaplasia procedure with pressure loading in TMJ.

Hyperglycemia regulates TXNIP/TRX/ROS axis via p38 MAPK and ERK pathways in pancreatic cancer.

PubMed

Li, Wei; Wu, Zheng; Ma, Qingyong; Liu, Jiangbo; Xu, Qinhong; Han, Liang; Duan, Wanxing; Lv, Yunfu; Wang, Fengfei; Reindl, Katie M; Wu, Erxi

2014-01-01

Approximately 85% of pancreatic cancer patients suffer from glucose intolerance or even diabetes because high glucose levels can contribute to oxidative stress which promotes tumor development. As one of the reactive oxygen species (ROS)-regulating factors, thioredoxin-interacting protein (TXNIP), is involved in the maintenance of thioredoxin (TRX)-mediated redox regulation. In this study, we demonstrated that high glucose levels increased the expression of TXNIP in time- and concentration-dependent manners and modulated the activity of TRX and ROS production in pancreatic cancer cells, BxPC-3 and Panc-1. We also found that glucose activated both p38 MAPK and ERK pathways and inhibitors of these pathways impaired the TXNIP/TRX/ROS axis. Knockdown of TXNIP restored TRX activity and decreased ROS production under high glucose conditions. Moreover, we observed that the integrated optical density (IOD) of TXNIP staining as well as the protein and mRNA expression levels of TXNIP were higher in the tumor tissues of pancreatic cancer patients with diabetes. Taken together, these results indicate that hyperglycemia-induced TXNIP expression is involved in diabetes-mediated oxidative stress in pancreatic cancer via p38 MAPK and ERK pathways.

Coriolus versicolor aqueous extract ameliorates insulin resistance with PI3K/Akt and p38 MAPK signaling pathways involved in diabetic skeletal muscle.

PubMed

Xian, Hui-Min; Che, Hui; Qin, Ying; Yang, Fan; Meng, Song-Yan; Li, Xiao-Guang; Bai, Yun-Long; Wang, Li-Hong

2018-03-01

Patients with type 2 diabetes mellitus (T2DM) are usually with poor immunity and easier to suffer from cancer and microbial infections. Herein, we report an efficient anti-diabetic medicinal mushroom, Coriolus versicolor (CV). This study aimed to investigate the anti-diabetic and anti-insulin-resistance effects of CV aqueous extract in myoblasts (L6 cells) and skeletal muscle of T2DM rat. Our results showed that CV extract treatment significantly reduced blood glucose levels of T2DM rats, whereas CV extract increased glucose consumption in insulin resistant L6 cells. Besides, the translocation and expression of glucose transporter 4 were enhanced by CV extract, which indicated that CV extract was effective in diabetic skeletal muscle. Moreover, CV extract treatments resulted in remarkable anti-insulin-resistance effects, which was reflected by the change of gene and protein expression levels in PI3K/Akt and p38 MAPK pathways. PI3K inhibitor, LY29004, and p38 MAPK inhibitor, SB203580 confirmed it further. In conclusion, our results demonstrated that the CV extract exhibited anti-diabetic and anti-insulin-resistance effects in diabetic skeletal muscle, and the effects were mediated by PI3K/Akt and p38 MAPK pathways. These findings are remarkable when considering the use of commercially available CV by diabetic patients who also suffer from cancer or microbial infections. Copyright © 2017 John Wiley & Sons, Ltd.

ISA virus regulates the generation of reactive oxygen species and p47phox expression in a p38 MAPK-dependent manner in Salmo salar.

PubMed

Olavarría, Víctor H; Valdivia, Sharin; Salas, Boris; Villalba, Melina; Sandoval, Rodrigo; Oliva, Harold; Valdebenito, Samuel; Yañez, Alejandro

2015-02-01

Several viruses, including Orthomyxovirus, utilize cellular reactive oxygen species (ROS) for viral genomic replication and survival within host cells. However, the role of ROS in early events of viral entry and signal induction has not been elucidated. Here, we show that ISA virus (ISAV) induces ROS production very early during infection of CHSE-214 and SHK-1Ycells, and that production is sustained over the observed 24h post-infection. The mitogen-activated protein kinase (MAPK) family is responsible for important signaling pathways. In this study, we report that ISAV activates ERK and p38 in Salmo salar. In salmonid macrophages, while ERK was required for SOD, GLURED, p47phox expression, p38 regulated the ROS production by the NADPH oxidase complex activation. These results, together with the presence of several consensus target motifs for p38 MAPK in the promoter of the S. salar p47phox gene, suggest that p38 MAPK regulates p47phox gene expression in fish through the activation of this key transcription factor. Copyright © 2014 Elsevier Ltd. All rights reserved.

Low-dose occupational exposure to benzene and signal transduction pathways involved in the regulation of cellular response to oxidative stress.

PubMed

Fenga, Concettina; Gangemi, Silvia; Giambò, Federica; Tsitsimpikou, Christina; Golokhvast, Kirill; Tsatsakis, Aristidis; Costa, Chiara

2016-02-15

Benzene metabolism seems to modulate NF-κB, p38-MAPK (mitogen-activated protein kinase) and signal transducer and activator of transcription 3 (STAT3) signalling pathways via the production of reactive oxygen species. This study aims to evaluate the effects of low-dose, long-term exposure on NF-κB, STAT3, p38-MAPK and stress-activated protein kinase/Jun amino-terminal kinase (SAPK/JNK) signal transduction pathways in peripheral blood mononuclear cells in gasoline station attendants. The influence of consumption of vegetables and fruits on these pathways has also been evaluated. A total of 91 men, employed in gasoline stations located in eastern Sicily, were enrolled for this study and compared with a control group of 63 male office workers with no history of exposure to benzene. The exposure was assessed by measuring urinary trans,trans-muconic acid (t,t-MA) concentration. Quantitative analyses were performed for proteins NF-κB p65, phospho-NF-κB p65, phospho-IκB-α, phospho-SAPK/JNK, phospho-p38 MAPK and phospho-STAT3 using an immunoenzymatic assay. The results of this study indicate significantly higher t,t-MA levels in gasoline station attendants. With regard to NF-κB, phospho-IκB-α and phospho-STAT3 proteins, statistically significant differences were observed in workers exposed to benzene. However, no differences were observed in SAPK/JNK and p38-MAPK activation. These changes were positively correlated with t,t-MA levels, but only phospho-NF-κB p65 was associated with the intake of food rich in antioxidant active principles. Chronic exposure to low-dose benzene can modulate signal transduction pathways activated by oxidative stress and involved in cell proliferation and apoptosis. This could represent a possible mechanism of carcinogenic action of chronic benzene exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

JWA gene regulates PANC-1 pancreatic cancer cell behaviors through MEK-ERK1/2 of the MAPK signaling pathway.

PubMed

Wu, Yuan-Yuan; Ma, Tie-Liang; Ge, Zhi-Jun; Lin, Jie; Ding, Wei-Liang; Feng, Jia-Ke; Zhou, Su-Jun; Chen, Guo-Chang; Tan, Yong-Fei; Cui, Guo-Xing

2014-10-01

The present study aimed to investigate the role of JWA gene in the proliferation, apoptosis, invasion and migration of PANC-1 pancreatic cancer cells and the effect on the MAPK signaling pathway. Human PANC-1 pancreatic cancer cells were cultured in vitro , and small interfering RNA (siRNA) was designed for the JWA gene. The siRNA was transfected into PANC-1 cells. Subsequently, the cell proliferation was measured by MTT assay; cell apoptosis was detected by analyzing BAX and Bcl-2 protein expression; cell migration and invasion were measured using Transwell ® chambers; and the protein expression of JWA and ERK1/2, JNK and p38 and their phosphorylated forms were measured by western blotting. By utilizing the MTT assay, the results showed that when JWA protein expression was inhibited, the proliferation of PANC-1 cells was enhanced. In addition, the expression of apoptosis-associated protein (AAP) BAX was substantially decreased, while the expression of the apoptosis inhibitor gene, Bcl-2 , was significantly enhanced. Using Transwell chambers, it was found that the number of penetrating PANC-1 cells was significantly increased after transfection with JWA siRNA, suggesting that the migration and invasion of the cells was substantially increased. By studying the association between JWA and the MAPK pathway in PANC-1 cells, it was found that the expression of p-ERK1/2 of the MAPK pathway was significantly downregulated following JWA siRNA transfection. However, the expression levels of ERK1/2, JNK, p38, p-JNK and p-p38 showed no significant differences. In conclusion, it was shown that JWA affects the proliferation, apoptosis, invasion and migration of PANC-1 pancreatic cancer cells which could be attributed to effects on the expression of ERK1/2 in the MAPK pathway.

p38 Mitogen-Activated Protein Kinase/Signal Transducer and Activator of Transcription-3 Pathway Signaling Regulates Expression of Inhibitory Molecules in T Cells Activated by HIV-1–Exposed Dendritic Cells

PubMed Central

Che, Karlhans Fru; Shankar, Esaki Muthu; Muthu, Sundaram; Zandi, Sasan; Sigvardsson, Mikael; Hinkula, Jorma; Messmer, Davorka; Larsson, Marie

2012-01-01

Human immunodeficiency virus type 1 (HIV-1) infection enhances the expression of inhibitory molecules on T cells, leading to T-cell impairment. The signaling pathways underlying the regulation of inhibitory molecules and subsequent onset of T-cell impairment remain elusive. We showed that both autologous and allogeneic T cells exposed to HIV-pulsed dendritic cells (DCs) upregulated cytotoxic T-lymphocyte antigen (CTLA-4), tumor-necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), lymphocyte-activation gene-3 (LAG3), T-cell immunoglobulin mucin-3 (TIM-3), CD160 and certain suppression-associated transcription factors, such as B-lymphocyte induced maturation protein-1 (BLIMP-1), deltex homolog 1 protein (DTX1) and forkhead box P3 (FOXP3), leading to T-cell suppression. This induction was regulated by p38 mitogen-activated protein kinase/signal transducer and activator of transcription-3 (P38MAPK/STAT3) pathways, because their blockade significantly abrogated expression of all the inhibitory molecules studied and a subsequent recovery in T-cell proliferation. Neither interleukin-6 (IL-6) nor IL-10 nor growth factors known to activate STAT3 signaling events were responsible for STAT3 activation. Involvement of the P38MAPK/STAT3 pathways was evident because these proteins had a higher level of phosphorylation in the HIV-1–primed cells. Furthermore, blockade of viral CD4 binding and fusion significantly reduced the negative effects DCs imposed on primed T cells. In conclusion, HIV-1 interaction with DCs modulated their functionality, causing them to trigger the activation of the P38MAPK/STAT3 pathway in T cells, which was responsible for the upregulation of inhibitory molecules. PMID:22777388

OSU-DY7, a novel D-tyrosinol derivative, mediates cytotoxicity in chronic lymphocytic leukaemia and Burkitt lymphoma through p38 mitogen-activated protein kinase pathway

PubMed Central

Bai, Li-Yuan; Ma, Yihui; Kulp, Samuel K.; Wang, Shu-Huei; Chiu, Chang-Fang; Frissora, Frank; Mani, Rajeswaran; Mo, Xiaokui; Jarjoura, David; Byrd, John C.; Chen, Ching-Shih; Muthusamy, Natarajan

2013-01-01

Summary Drug resistance and associated immune deregulation limit use of current therapies in chronic lymphocytic leukaemia (CLL), thus warranting alternative therapy development. Herein we demonstrate that OSU-DY7, a novel D-tyrosinol derivative targeting p38 mitogen-activated protein kinase (MAPK), mediates cytotoxicity in lymphocytic cell lines representing CLL (MEC-1), acute lymphoblastic leukaemia (697 cells), Burkitt lymphoma (Raji and Ramos) and primary B cells from CLL patients in a dose- and time-dependent manner. The OSU-DY7-induced cytotoxicity is dependent on caspase activation, as evidenced by induction of caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage and rescue of cytotoxicity by Z-VAD-FMK. Interestingly, OSU-DY7-induced cytotoxicity is mediated through activation of p38 MAPK, as evidenced by increased phosphorylation of p38 MAPK and downstream target protein MAPKAPK2. Pretreatment of B-CLL cells with SB202190, a specific p38 MAPK inhibitor, results in decreased MAPKAPK2 protein level with concomitant rescue of the cells from OSU-DY7-mediated cytotoxicity. Furthermore, OSU-DY7-induced cytotoxicity is associated with down regulation of p38 MAPK target BIRC5, that is rescued at protein and mRNA levels by SB202190. This study provides evidence for a role of OSU-DY7 in p38 MAPK activation and BIRC5 down regulation associated with apoptosis in B lymphocytic cells, thus warranting development of this alternative therapy for lymphoid malignancies. PMID:21470196

Effect of β-glucan on MUC4 and MUC5B expression in human airway epithelial cells.

PubMed

Kim, Yong-Dae; Bae, Chang Hoon; Song, Si-Youn; Choi, Yoon Seok

2015-08-01

β-Glucan is found in the cell walls of fungi, bacteria, and some plant tissues, and is detected by the innate immune system. Furthermore, this recognition is known to worsen respiratory symptoms in patients with allergic and inflammatory airway diseases. However, the means by which β-glucan affects the secretion of major mucins by human airway epithelial cells has not been elucidated. Therefore, in this study, the effect and signaling pathway of β-glucan on mucins MUC4 and MUC5B were investigated in human airway epithelial cells. In NCI-H292 cells and human normal nasal epithelial cells, the effect and signaling pathway of β-glucan on MUC4 and MUC5B expression were investigated using reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR, enzyme immunoassay, and immunoblot analysis with specific inhibitors and small interfering RNA (siRNA). β-Glucan increased MUC4 and MUC5B expression and activated the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). SB203580 (a p38 MAPK inhibitor) and pyrrolidine dithiocarbamate (PDTC; a NF-κB inhibitor) inhibited β-glucan-induced MUC4 and MUC5B expression. In addition, siRNA knockdown of p38 MAPK blocked β-glucan-induced MUC4 and MUC5B mRNA expression and β-glucan-activated phosphorylation of NF-κB. Furthermore, Toll-like receptor 4 (TLR4) mRNA expression was increased by β-glucan, and siRNA knockdown of TLR4 blocked β-glucan-induced MUC4 and MUC5B mRNA expression and β-glucan-activated phosphorylation of p38 MAPK and NF-κB. These results demonstrate that in human airway epithelial cells β-glucan induces MUC4 and MUC5B expression via the TLR4-p38 MAPK-NF-κB signaling pathway. © 2015 ARS-AAOA, LLC.

Cardioprotective role of P38 MAPK during myocardial infarction via parallel activation of α-crystallin B and Nrf2.

PubMed

Mitra, Arkadeep; Ray, Aramita; Datta, Ritwik; Sengupta, Shantanu; Sarkar, Sagartirtha

2014-09-01

Myocardial infarction (MI) is defined as cardiac cell death due to prolonged ischemia. Although necrotic cell death was considered to be solely responsible for myocyte death during MI, it was recently revealed that apoptosis also plays its part in this death process. Our laboratory has recently shown that endoplasmic reticulum (ER) stress-induced apoptosis is the predominant route for apoptosis during MI and the conventional mitochondrial pathway is bypassed by activation of a small heat shock protein α-crystallin B (CRYAB). Since CRYAB is a direct target of P38 mitogen-activated protein kinase (MAPK) cascade, we were prompted to check the role of P38 MAPK in 20-week-old male Wister rats immediately after infarct formation. Interestingly, parallel activation of mitochondrial apoptotic pathway with an increase in ER stress-induced apoptotic load was observed along with decreased activation of CRYAB and Nrf2 (a pro-survival protein activated in response to ER stress) in MI rats treated with SB203580, a specific inhibitor of P38α and P38β compared to the MI alone. As a cumulative effect, this inhibitor treatment also resulted in significant increase in the levels of caspase3 activity and TUNEL positivity, the end point apoptotic markers. Furthermore, SB203580-treated hypoxic adult cardiomyocytes showed formation of desmin aggregates which were previously associated with impaired cardiac function. Thus, this study shows for the first time the precise mechanism by which P38 MAPK plays a pro-survival role and confers protection of cardiomyocytes, during infarct formation. © 2014 Wiley Periodicals, Inc.

ROS generation and MAPKs activation contribute to the Ni-induced testosterone synthesis disturbance in rat Leydig cells.

PubMed

Han, Aijie; Zou, Lingyue; Gan, Xiaoqin; Li, Yu; Liu, Fangfang; Chang, Xuhong; Zhang, Xiaotian; Tian, Minmin; Li, Sheng; Su, Li; Sun, Yingbiao

2018-06-15

Nickel (Ni) can disorder testosterone synthesis in rat Leydig cells, whereas the mechanisms remain unclear. The aim of this study was to investigate the role of reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs) in Ni-induced disturbance of testosterone synthesis in rat Leydig cells. The testosterone production and ROS levels were detected in Leydig cells. The mRNA and protein levels of testosterone synthetase, including StAR, CYP11A1, 3β-HSD, CYP17A1 and 17β-HSD, were determined. Effects of Ni on the ERK1/2, p38 and JNK MAPKs were also investigated. The results showed that Ni triggered ROS generation, consequently resulted in the decrease of testosterone synthetase expression and testosterone production in Leydig cells, which were then attenuated by ROS scavengers of N-acetylcysteine (NAC) and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), indicating that ROS are involved in the Ni-induced testosterone biosynthesis disturbance. Meanwhile Ni activated the ERK1/2, p38 and JNK MAPKs. Furthermore, Ni-inhibited testosterone synthetase expression levels and testosterone secretion were all alleviated by co-treatment with MAPK specific inhibitors (U0126 and SB203580, respectively), implying that Ni inhibited testosterone synthesis through activating ERK1/2 and p38 MAPK signal pathways in Leydig cells. In conclusion, these findings suggest that Ni causes testosterone synthesis disorder, partly, via ROS and MAPK signal pathways. Copyright © 2018 Elsevier B.V. All rights reserved.

Krüppel-like factor 17 inhibits urokinase plasminogen activator gene expression to suppress cell invasion through the Src/p38/MAPK signaling pathway in human lung adenocarcinoma

PubMed Central

Huang, Shuai; Li, Jiong; Liu, Xiao-Yan; Pan, Xing-Fei; Wang, Qin-Qin; Chen, Li; Lin, Ming-Juan; Huang, Zhi-Hong; Ma, Hong-Ming; Wu, Yi; Liu, Sheng-Ming; Zhou, Yan-Bin

2017-01-01

Krüppel-like factor 17 (KLF17) has been reported to be involved in invasion and metastasis suppression in lung cancer, but the molecular mechanisms underlying the anti-invasion and anti-metastasis roles of KLF17 in lung cancer are not fully illustrated. Here, we showed that KLF17 inhibited the invasion of A549 and H322 cells; the anti-invasion effect of KLF17 was associated with the suppression of urokinase plasminogen activator (uPA/PLAU) expression. KLF17 can bind with the promoter of uPA and inhibit its expression. Enforced expression of uPA abrogated the anti-invasion effect of KLF17 in A549 and H322 cells. In addition, immunohistochemistry staining showed that the protein expression of KLF17 was negatively correlated with that of uPA in archived samples from patients with lymph node metastasis of lung adenocarcinoma (rho = −0.62, P = 0.01). The mutually exclusive expression of KLF17 with uPA could predict lymph node metastasis for lung adenocarcinoma (AUC = 0.758, P = 0.005). Enforced expression of KLF17 inhibited the expression of phosphorylated Src and phosphorylated p38/MAPK in A549 and H322 cells. The invasiveness of the cells were suppressed by treating with sb203580 (p38/MAPK inhibitor) or HY-13805 (PP2, Src inhibitor). furthermore, p38/MAPK inhibition could block the KLF17-induced reduction of p-p38/MAPK and uPA, and Src inhibition enhanced the KLF17-induced suppression of p-Src and uPA in A549 and H322 cells. In conclusion, our study indicated that KLF17 suppressed the uPA-mediated invasion of lung adenocarcinoma. The Src and p38/MAPK signaling pathways were suggested as mediators of KLF17-induced uPA inhibition, thus providing evidence that KLF17 might be a potential anti-invasion candidate for lung adenocarcinoma. PMID:28454121

The activation of p38 MAPK limits the abnormal proliferation of vascular smooth muscle cells induced by high sodium concentrations

PubMed Central

WU, YAN; ZHOU, JUAN; WANG, HUAN; WU, YUE; GAO, QIYUE; WANG, LIJUN; ZHAO, QIANG; LIU, PEINING; GAO, SHANSHAN; WEN, WEN; ZHANG, WEIPING; LIU, YAN; YUAN, ZUYI

2016-01-01

The aim of the present study was to ascertain whether high sodium levels can directly promote the proliferation of vascular smooth muscle cells (VSMCs) and to elucidate the underlying mechanisms. Additional sodium chloride (NaCl) was added to the routine culture medium. Cell proliferation was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay. The mRNA expression level of proliferating cell nuclear antigen (PCNA) was measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The protein expression levels of PCNA and phosphorylated c-Jun amino N-terminal kinase (p-JNK), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) were measured by western blot analysis. Cell proliferation assay revealed that Na+ rather than Cl− or osmotic pressure promoted the proliferation of the VSMCs. The high sodium level upregulated the expression of PCNA and the phosphorylation levels of JNK, ERK1/2 and p38 MAPK. The inhibition of JNK and ERK1/2 decreased PCNA expression. Of note, the inhibition of p38 MAPK using the inhibitor, SB203580, increased PCNA expression. However, when p38 MAPK was activated by anisomycin, PCNA expression was decreased. On the whole, our findings demonstrate that a relatively high sodium level per se directly promotes the proliferation of VSMCs through the JNK/ERK1/2/PCNA pathway. At the same time, this induction of the proliferation of VSMCs due to high sodium levels can be maintained at a low level via the activation of p38 MAPK. PMID:26530729

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Cui-Li, E-mail: zhangcuili@hotmail.com; Song, Fei; Zhang, Jing

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)more » 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.« less

Cigarette smoke induced urocystic epithelial mesenchymal transition via MAPK pathways.

PubMed

Yu, Dexin; Geng, Hao; Liu, Zhiqi; Zhao, Li; Liang, Zhaofeng; Zhang, Zhiqiang; Xie, Dongdong; Wang, Yi; Zhang, Tao; Min, Jie; Zhong, Caiyun

2017-01-31

Cigarette smoke has been shown to be a major risk factor for bladder cancer. Epithelial-mesenchymal transition (EMT) is a crucial process in cancer development. The role of MAPK pathways in regulating cigarette smoke-triggered urocystic EMT remains to be elucidated. Human normal urothelial cells and BALB/c mice were used as in vitro and in vivo cigarette smoke exposure models. Exposure of human normal urothelial cells to cigarette smoke induced morphological change, enhanced migratory and invasive capacities, reduced epithelial marker expression and increased mesenchymal marker expression, along with the activation of MAPK pathways. Moreover, we revealed that ERK1/2 and p38 inhibitors, but rather JNK inhibitor, effectively attenuated cigarette smoke-induced urocystic EMT. Importantly, the regulatory function of ERK1/2 and p38 pathways in cigarette smoke-triggered urocystic EMT was further confirmed in mice exposed to CS for 12 weeks. These findings could provide new insight into the molecular mechanisms of cigarette smoke-associated bladder cancer development as well as its potential intervention.

Integration of Golgi trafficking and growth factor signaling by the lipid phosphatase SAC1

PubMed Central

Blagoveshchenskaya, Anastasia; Cheong, Fei Ying; Rohde, Holger M.; Glover, Greta; Knödler, Andreas; Nicolson, Teresa; Boehmelt, Guido; Mayinger, Peter

2008-01-01

When a growing cell expands, lipids and proteins must be delivered to its periphery. Although this phenomenon has been observed for decades, it remains unknown how the secretory pathway responds to growth signaling. We demonstrate that control of Golgi phosphatidylinositol-4-phosphate (PI(4)P) is required for growth-dependent secretion. The phosphoinositide phosphatase SAC1 accumulates at the Golgi in quiescent cells and down-regulates anterograde trafficking by depleting Golgi PI(4)P. Golgi localization requires oligomerization of SAC1 and recruitment of the coat protein (COP) II complex. When quiescent cells are stimulated by mitogens, SAC1 rapidly shuttles back to the endoplasmic reticulum (ER), thus releasing the brake on Golgi secretion. The p38 mitogen-activated kinase (MAPK) pathway induces dissociation of SAC1 oligomers after mitogen stimulation, which triggers COP-I–mediated retrieval of SAC1 to the ER. Inhibition of p38 MAPK abolishes growth factor–induced Golgi-to-ER shuttling of SAC1 and slows secretion. These results suggest direct roles for p38 MAPK and SAC1 in transmitting growth signals to the secretory machinery. PMID:18299350

B7-H3 Augments Inflammatory Responses and Exacerbates Brain Damage via Amplifying NF-κB p65 and MAPK p38 Activation during Experimental Pneumococcal Meningitis.

PubMed

Chen, Xuqin; Li, Yan; Blankson, Siobhan; Liu, Min; Huang, Danping; Redmond, H Paul; Huang, Jing; Wang, Jiang Huai; Wang, Jian

2017-01-01

The costimulatory protein B7-H3 has been shown to play a contributory role in the development and progression of experimental pneumococcal meningitis by augmentation of the innate immunity-associated inflammatory response via a TLR2-dependent manner. This study aimed to clarify the component(s) of TLR2-mediated signal transduction pathways responsible for B7-H3-augmented inflammatory response and subsequent brain damage during experimental pneumococcal meningitis. Administration of B7-H3 did not augment expression of TLR2 and other TLR2 upstream components, but led to an enhanced formation of MyD88-IRAK immunocomplex in the brain of S. pneumoniae-infected mice. Furthermore, B7-H3 substantially augmented S. pneumoniae-induced activation of TLR2 downstream NF-κB p65 and MAPK p38 pathways in the brain of S. pneumoniae-infected mice. Notably, blockage of NF-κB p65 and/or MAPK p38 with their specific inhibitors strongly attenuated B7-H3-amplified inflammatory response with significantly reduced proinflammatory cytokine and chemokine production, and markedly ameliorated B7-H3-exacerbated disruption of blood-brain barrier and severity of disease status in S. pneumoniae-infected mice. These results indicate that targeting NF-κB p65 and/or MAPK p38 may represent a promising therapeutic option for amelioration of overwhelming inflammatory response-associated brain injury frequently observed during pneumococcal meningitis.

Colon cancer cells colonize the lung from established liver metastases through p38 MAPK signalling and PTHLH.

PubMed

Urosevic, Jelena; Garcia-Albéniz, Xabier; Planet, Evarist; Real, Sebastián; Céspedes, María Virtudes; Guiu, Marc; Fernandez, Esther; Bellmunt, Anna; Gawrzak, Sylwia; Pavlovic, Milica; Mangues, Ramon; Dolado, Ignacio; Barriga, Francisco M; Nadal, Cristina; Kemeny, Nancy; Batlle, Eduard; Nebreda, Angel R; Gomis, Roger R

2014-07-01

The mechanisms that allow colon cancer cells to form liver and lung metastases, and whether KRAS mutation influences where and when metastasis occurs, are unknown. We provide clinical and molecular evidence showing that different MAPK signalling pathways are implicated in this process. Whereas ERK2 activation provides colon cancer cells with the ability to seed and colonize the liver, reduced p38 MAPK signalling endows cancer cells with the ability to form lung metastasis from previously established liver lesions. Downregulation of p38 MAPK signalling results in increased expression of the cytokine PTHLH, which contributes to colon cancer cell extravasation to the lung by inducing caspase-independent death in endothelial cells of the lung microvasculature. The concerted acquisition of metastatic traits in the colon cancer cells together with the sequential colonization of liver and lung highlights the importance of metastatic lesions as a platform for further dissemination.

Activation of multiple mitogen-activated protein kinases by recombinant calcitonin gene-related peptide receptor.

PubMed

Parameswaran, N; Disa, J; Spielman, W S; Brooks, D P; Nambi, P; Aiyar, N

2000-02-18

Calcitonin gene-related peptide is a 37-amino-acid neuropeptide and a potent vasodilator. Although calcitonin gene-related peptide has been shown to have a number of effects in a variety of systems, the mechanisms of action and the intracellular signaling pathways, especially the regulation of mitogen-activated protien kinase (MAPK) pathway, is not known. In the present study we investigated the role of calcitonin gene-related peptide in the regulation of MAPKs in human embryonic kidney (HEK) 293 cells stably transfected with a recombinant porcine calcitonin gene-related peptide-1 receptor. Calcitonin gene-related peptide caused a significant dose-dependent increase in cAMP response and the effect was inhibited by calcitonin gene-related peptide(8-37), the calcitonin gene-related peptide-receptor antagonist. Calcitonin gene-related peptide also caused a time- and concentration-dependent increase in extracellular signal-regulated kinase (ERK) and P38 mitogen-activated protein kinase (P38 MAPK) activities, with apparently no significant change in cjun-N-terminal kinase (JNK) activity. Forskolin, a direct activator of adenylyl cyclase also stimulated ERK and P38 activities in these cells suggesting the invovement of cAMP in this process. Calcitonin gene-related peptide-stimulated ERK and P38 MAPK activities were inhibited significantly by calcitonin gene-related peptide receptor antagonist, calcitonin gene-related peptide-(8-37) suggesting the involvement of calcitonin gene-related peptide-1 receptor. Preincubation of the cells with the cAMP-dependent protein kinase inhibitor, H89 [¿N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide, hydrochloride¿] inhibited calcitonin gene-related peptide-mediated activation of ERK and p38 kinases. On the other hand, preincubation of the cells with wortmannin ¿[1S-(1alpha,6balpha,9abeta,11alpha, 11bbeta)]-11-(acetyloxy)-1,6b,7,8,9a,10,11, 11b-octahydro-1-(methoxymethyl)-9a,11b-dimethyl-3H-furo[4,3, 2-de]indeno[4,5-h]-2-benzopyran-3,6,9-trione¿, a PI3-kinase inhibitor, attenuated only calcitonin gene-related peptide-induced ERK and not P38 MAPK activation. Thus, these data suggest that activation of ERK by calcitonin gene-related peptide involves a H89-sensitive protein kinase A and a wortmannin-sensitive PI3-kinase while activation of p38 MAPK by calcitonin gene-related peptide involves only the H89 sensitive pathway and is independent of PI3 kinase. This also suggests that although both ERK and P38 can be activated by protein kinase A, the distal signaling components to protein kinase A in the activation of these two kinases (ERK and P38) are different.

Role of protein kinase C in TBT-induced inhibition of lytic function and MAPK activation in human natural killer cells.

PubMed

Abraha, Abraham B; Rana, Krupa; Whalen, Margaret M

2010-11-01

Human natural killer (NK) cells are lymphocytes that destroy tumor and virally infected cells. Previous studies have shown that exposure of NK cells to tributyltin (TBT) greatly diminishes their ability to destroy tumor cells (lytic function) while activating mitogen-activated protein kinases (MAPK) (p44/42, p38, and JNK) in NK cells. The signaling pathway that regulates NK lytic function appears to include activation of protein kinase C(PKC) as well as MAPK activity. TBT-induced activation of MAPKs would trigger a portion of the NK lytic signaling pathway, which would then leave the NK cell unable to trigger this pathway in response to a subsequent encounter with a target cell. In the present study we evaluated the involvement of PKC in inhibition of NK lysis of tumor cells and activation of MAPKs caused by TBT exposure. TBT caused a 2–3-fold activation of PKC at concentrations ranging from 50 to 300 nM (16–98 ng/ml),indicating that activation of PKC occurs in response to TBT exposure. This would then leave the NK cell unable to respond to targets. Treatment with the PKC inhibitor, bisindolylmaleimide I, caused an 85% decrease in the ability of NK cells to lyse tumor cells, validating the involvement of PKC in the lytic signaling pathway. The role of PKC in the activation of MAPKs by TBT was also investigated using bisindolylmaleimide I. The results indicated that, in NK cells where PKC activation was blocked, there was no activation of the MAPK, p44/42 in response to TBT.However, TBT-induced activation of the MAPKs, p38 and JNK did not require PKC activation. These results indicate the pivotal role of PKC in the TBT-induced loss of NK lytic function including activation of p44/42 by TBT in NK cells.

Role of protein kinase C in the TBT-induced inhibition of lytic function and MAPK activation in human natural killer cells

PubMed Central

Abraha, Abraham B.; Rana, Krupa; Whalen, Margaret M.

2010-01-01

Human natural killer (NK) cells are lymphocytes that destroy tumor and virally infected cells. Previous studies have shown that exposures of NK cells to tributyltin (TBT) greatly diminish their ability to destroy tumor cells (lytic function) while activating mitogen-activated protein kinases (MAPK) (p44/42, p38, and JNK) in the NK cells. The signaling pathway that regulates NK lytic function appears to include activation of protein kinase C (PKC) as well as MAPK activity. The TBT-induced activation of MAPKs would trigger a portion of the NK lytic signaling pathway, which would then leave the NK cell unable to trigger this pathway in response to a subsequent encounter with a target cell. In the present study we evaluated the involvement of PKC in the inhibition of NK lysis of tumor cells and activation of MAPKs caused by TBT exposures. TBT caused a 2–3 fold activation of PKC at concentrations ranging from 50–300 nM (16–98 ng/mL), indicating that activation of PKC occurs in response to TBT exposures. This would then leave the NK cell unable to respond to targets. Treatment with the PKC inhibitor, bisindolylmaleimide I, caused an 85% decrease in the ability of NK cells to lyse tumor cells validating the involvement of PKC in the lytic signaling pathway. The role of PKC in the activation of MAPKs by TBT was also investigated using bisindolylmaleimide I. The results indicated that in NK cells where PKC activation was blocked there was no activation of the MAPK, p44/42 in response to TBT. However, TBT-induced activation of the MAPKs, p38 and JNK did not require PKC activation. These results indicate the pivotal role of PKC in the TBT-induced loss of NK lytic function including the activation of p44/42 by TBT in NK cells. PMID:20390410

Emodin Inhibition of Influenza A Virus Replication and Influenza Viral Pneumonia via the Nrf2, TLR4, p38/JNK and NF-kappaB Pathways.

PubMed

Dai, Jian-Ping; Wang, Qian-Wen; Su, Yun; Gu, Li-Ming; Zhao, Ying; Chen, Xiao-Xua; Chen, Cheng; Li, Wei-Zhong; Wang, Ge-Fei; Li, Kang-Sheng

2017-10-18

Lasting activations of toll-like receptors (TLRs), MAPK and NF-κB pathways can support influenza A virus (IAV) infection and promote pneumonia. In this study, we have investigated the effect and mechanism of action of emodin on IAV infection using qRT-PCR, western blotting, ELISA, Nrf2 luciferase reporter, siRNA and plaque inhibition assays. The results showed that emodin could significantly inhibit IAV (ST169, H1N1) replication, reduce IAV-induced expressions of TLR2/3/4/7, MyD88 and TRAF6, decrease IAV-induced phosphorylations of p38/JNK MAPK and nuclear translocation of NF-κB p65. Emodin also activated the Nrf2 pathway, decreased ROS levels, increased GSH levelss and GSH/GSSG ratio, and upregulated the activities of SOD, GR, CAT and GSH-Px after IAV infection. Suppression of Nrf2 via siRNA markedly blocked the inhibitory effects of emodin on IAV-induced activations of TLR4, p38/JNK, and NF-κB pathways and on IAV-induced production of IL-1β, IL-6 and expression of IAV M2 protein. Emodin also dramatically increased the survival rate of mice, reduced lung edema, pulmonary viral titer and inflammatory cytokines, and improved lung histopathological changes. In conclusion, emodin can inhibit IAV replication and influenza viral pneumonia, at least in part, by activating Nrf2 signaling and inhibiting IAV-induced activations of the TLR4, p38/JNK MAPK and NF-κB pathways.

p38 MAP kinase is required for Wnt3a-mediated osterix expression independently of Wnt-LRP5/6-GSK3β signaling axis in dental follicle cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakisaka, Yukihiko; Kanaya, Sousuke; Liason Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575

Wnt3a is a secreted glycoprotein that activates the glycogen synthase kinase-3β (GSK3β)/β-catenin signaling pathway through low-density-lipoprotein receptor-related protein (LRP)5/6 co-receptors. Wnt3a has been implicated in periodontal development and homeostasis, as well as in cementum formation. Recently, we have reported that Wnt3a increases alkaline phosphatase expression through the induction of osterix (Osx) expression in dental follicle cells, a precursor of cementoblasts. However, the molecular mechanism by which Wnt3a induces Osx expression is still unknown. In this study, we show that Wnt3a-induced Osx expression was inhibited in the presence of p38 mitogen-activated protein kinase (MAPK) inhibitors (SB203580 and SB202190) at gene andmore » protein levels, as assessed by real-time PCR and immunocytohistochemistry, respectively. Pretreatment of cells with Dickkopf-1, a potent canonical Wnt antagonist binding to LRP5/6 co-receptors, did not influence Wnt3a-mediated p38 MAPK phosphorylation, suggesting that Wnt3a activates p38 MAPK through LRP5/6-independent signaling. On the other hand, pretreatment with p38 MAPK inhibitors had no effects on the phosphorylated status of GSK3β and β-catenin as well as β-catenin nuclear translocation, but inhibited Wnt3a-mediated β-catenin transcriptional activity. These findings suggest that p38 MAPK modulates canonical Wnt signaling at the β-catenin transcriptional level without any crosstalk with the Wnt3a-mediated LRP5/6-GSK3β signaling axis and subsequent β-catenin nuclear translocation. These findings expand our knowledge of the mechanisms controlling periodontal development and regeneration. - Highlights: • Wnt3a induces Osx expression via p38 MAPK signaling in dental follicle cells. • p38 MAPK has no crosstalk with Wnt3a-mediated LRP5/6 and GSK3β signaling. • p38 MAPK is required for Wnt signaling at the β-catenin transcriptional level.« less

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hao, Yuhui; Liu, Cong; Huang, Jiawei

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

p38α MAPK Is Required for Tooth Morphogenesis and Enamel Secretion*

PubMed Central

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

2015-01-01

An improved understanding of the molecular pathways that drive tooth morphogenesis and enamel secretion is needed to generate teeth from organ cultures for therapeutic implantation or to determine the pathogenesis of primary disorders of dentition (Abdollah, S., Macias-Silva, M., Tsukazaki, T., Hayashi, H., Attisano, L., and Wrana, J. L. (1997) J. Biol. Chem. 272, 27678–27685). Here we present a novel ectodermal dysplasia phenotype associated with conditional deletion of p38α MAPK in ectodermal appendages using K14-cre mice (p38αK14 mice). These mice display impaired patterning of dental cusps and a profound defect in the production and biomechanical strength of dental enamel because of defects in ameloblast differentiation and activity. In the absence of p38α, expression of amelogenin and β4-integrin in ameloblasts and p21 in the enamel knot was significantly reduced. Mice lacking the MAP2K MKK6, but not mice lacking MAP2K MKK3, also show the enamel defects, implying that MKK6 functions as an upstream kinase of p38α in ectodermal appendages. Lastly, stimulation with BMP2/7 in both explant culture and an ameloblast cell line confirm that p38α functions downstream of BMPs in this context. Thus, BMP-induced activation of the p38α MAPK pathway is critical for the morphogenesis of tooth cusps and the secretion of dental enamel. PMID:25406311

Helicobacter pylori neutrophil-activating protein induces release of histamine and interleukin-6 through G protein-mediated MAPKs and PI3K/Akt pathways in HMC-1 cells.

PubMed

Tsai, Chung-Che; Kuo, Ting-Yu; Hong, Zhi-Wei; Yeh, Ying-Chieh; Shih, Kuo-Shun; Du, Shin-Yi; Fu, Hua-Wen

2015-01-01

Helicobacter pylori neutrophil-activating protein (HP-NAP) activates several innate leukocytes including neutrophils, monocytes, and mast cells. It has been reported that HP-NAP induces degranulation and interleukin-6 (IL-6) secretion of rat peritoneal mast cells. However, the molecular mechanism is not very clear. Here, we show that HP-NAP activates human mast cell line-1 (HMC-1) cells to secrete histamine and IL-6. The secretion depends on pertussis toxin (PTX)-sensitive heterotrimeric G proteins but not on Toll-like receptor 2. Moreover, HP-NAP induces PTX-sensitive G protein-mediated activation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38-mitogen-activated protein kinase (p38 MAPK), and Akt in HMC-1 cells. Inhibition of ERK1/2, p38 MAPK, or phosphatidylinositol 3-kinase (PI3K) suppresses HP-NAP-induced release of histamine and IL-6 from HMC-1 cells. Thus, the activation of HMC-1 cells by HP-NAP is through Gi-linked G protein-coupled receptor-mediated MAPKs and PI3K/Akt pathways.

Comparative study of the efficacy of pulsed electromagnetic field and low level laser therapy on mitogen-activated protein kinases.

PubMed

El-Makakey, Ayman M; El-Sharaby, Radwa M; Hassan, Mohammed H; Balbaa, Alaa

2017-03-01

Mitogen-Activated Protein Kinases (MAPKs) consist of three major signaling members: extracellular signal-regulated kinase (ERK), p38 and C-JUN N-terminal kinase (JNK). We investigated physiological effects of Pulsed Electromagnetic Field Therapy (PEMFT) and Low Level Laser Therapy (LLLT) on human body, adopting the expression level of mitogen-activated protein kinases as an indicator via assessment of the activation levels of three major families of MAPKS, ERK, p38 and JNK in the peripheral lymphocytes of patients before and after the therapies. Assessment for the expression levels of MAPKs families' were done, in the peripheral lymphocytes of patients recently have appendectomy, using flow cytometric analysis of multiple signaling pathways, pre and post LLLT and PEMFT application (twice daily for 6 successive days) on the appendectomy wound. There were non-significant differences in the expression levels of MAPKs families' pre- therapies application. But there were significant increase in the ERK expression levels post application of LLLT compared to its pre application (p<0.01). Also, there was significant increase in the ERK, p38 and C-Jun N terminal expression level values post application of PEMFT compared to its pre application expression levels (p<0.01 for each). The present study demonstrates that PEMFT has a powerful healing effect more than LLLT as it increase the activation of ERK, P38 and C-Jun-N Terminal while LLLT only increase the activation of ERK. LLLT has more potent pain decreasing effect than PEMFT as it does not activate P38 pathway like PEMFT.

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

PubMed

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

2002-05-01

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

Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats.

PubMed

Chang, Xue-Ying; Cui, Lei; Wang, Xing-Zhi; Zhang, Lei; Zhu, Dan; Zhou, Xiao-Rong; Hao, Li-Rong

2017-01-01

This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d), 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS)/p38 mitogen activated protein kinase (p38MAPK) pathway was determined to explore the potential mechanism. Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA) and creatinine levels, malonaldehyde (MDA) content, and superoxide dismutase (SOD) activity in serum and the increases of calcium and alkaline phosphatase (ALP) activity in the aorta ( P < 0.05) and attenuated calcification and calcium accumulation in the medial layer of vasculature in histopathology. Western blot analysis showed that iNOS/p38MAPK pathway was normalized by the quercetin supplementation. Quercetin exerted a protective effect on vascular calcification in adenine-induced chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

PubMed Central

Chang, Xue-ying; Cui, Lei; Wang, Xing-zhi; Zhang, Lei; Zhu, Dan

2017-01-01

Background This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. Methods 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d), 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS)/p38 mitogen activated protein kinase (p38MAPK) pathway was determined to explore the potential mechanism. Results Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA) and creatinine levels, malonaldehyde (MDA) content, and superoxide dismutase (SOD) activity in serum and the increases of calcium and alkaline phosphatase (ALP) activity in the aorta (P < 0.05) and attenuated calcification and calcium accumulation in the medial layer of vasculature in histopathology. Western blot analysis showed that iNOS/p38MAPK pathway was normalized by the quercetin supplementation. Conclusions Quercetin exerted a protective effect on vascular calcification in adenine-induced chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway. PMID:28691026

Arsenic trioxide inhibits Ewing's sarcoma cell invasiveness by targeting p38(MAPK) and c-Jun N-terminal kinase.

PubMed

Zhang, Shuai; Guo, Wei; Ren, Ting-Ting; Lu, Xin-Chang; Tang, Guo-Qing; Zhao, Fu-Long

2012-01-01

Ewing's sarcoma is the second most frequent primary malignant bone tumor, mainly affecting children and young adults. The notorious metastatic capability of this tumor aggravates patient mortality and remains a problem to be overcome. We investigated the effect of arsenic trioxide (As₂O₃) on the metastasis capability of Ewing's sarcoma cells. We performed 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide assays to choose appropriate concentrations of As₂O₃ for the experiments. Migration, invasion, and adhesion assays were performed to assess the effect of As₂O₃ on the metastasis of Ewing's sarcoma. Immunofluorescent staining was used to observe cytoskeleton reorganization in Ewing's sarcoma cells treated with As₂O₃. Changes in matrix metalloproteinase-9 expression and the mitogen-activated protein kinase (MAPK) pathway were investigated using western blot. Inhibitors of p38(MAPK) (sb202190) and c-Jun NH₂-terminal kinase (JNK, sp600125) were used in invasion assays to determine the effect of p38(MAPK) and JNK. We found that As₂O₃ may markedly inhibit the migration and invasion capacity of Ewing's sarcoma cells with structural rearrangements of the actin cytoskeleton. The expressions of matrix metalloproteinase-9, phosphor-p38(MAPK), and phosphor-JNK were suppressed by As₂O₃ treatment in a dose-dependent manner. The inhibitors of p38(MAPK) (sb202190) and JNK (sp600125) enhanced the inhibition induced by As₂O₃, which was counteracted by anisomycin, an activating agent of p38(MAPK) and JNK. Taken together, our results demonstrate that As₂O₃ can inhibit the metastasis capability of RD-ES and A-673 cells and may have new therapeutic value for Ewing's sarcoma.

Tissue Factor Inflammatory Response Regulated by Promoter Genotype and p38 MAPK in Neonatal vs. Adult Microvascular Endothelial Cells

PubMed Central

Buzby, Jeffrey S.; Williams, Shirley A.; Imfeld, Karen L.; Kunicki, Thomas J.; Nugent, Diane J.

2014-01-01

Objective and design Variable tissue factor (TF) expression by human microvascular endothelial cells (HMVEC) may be regulated by two promoter haplotypes, distinguished by an 18 base pair deletion (D) or insertion (I) at -1208. We sought to determine the relationship between these haplotypes and interleukin-1 (IL-1α)-induced TF expression in neonatal versus adult HMVEC. Results IL-1-stimulated TF mRNA, protein, and activity were significantly higher in neonatal compared to adult D/D donors. IL-1-stimulated HMVEC from neonatal D/D donors expressed 3-fold higher levels of TF mRNA, 2-fold higher TF protein, and 4-fold increased TF activity compared to HMVEC from adult D/D donors. These results indicate that homozygosity for the D haplotype is characterized by increased response to IL-1 in neonates but not adults. IL-1 induced increased phosphorylation of p38 mitogen-activated protein kinase (MAPK), which was significantly greater in neonatal compared to adult HMVEC. Moreover, inhibition of the p38 MAPK pathway reduced IL-1-stimulated TF mRNA expression in D/D neonatal but not adult HMVEC. Conclusions Up-regulation of D/D neonatal HMVEC TF expression by IL-1 is mediated through the p38 MAPK pathway. This heightened response of D/D neonatal HMVEC to inflammatory stimuli may contribute to increased microvascular coagulopathies in susceptible newborn infants. PMID:24385191

Mitogen-activated protein kinase pathway mediates DBP-maf-induced apoptosis in RAW 264.7 macrophages.

PubMed

Gumireddy, Kiranmai; Reddy, C Damodar; Swamy, Narasimha

2003-09-01

Vitamin D-binding protein-macrophage-activating factor (DBP-maf) is derived from serum vitamin D binding protein (DBP) by selective deglycosylation during inflammation. In the present study, we investigated the effect of DBP-maf on RAW 264.7 macrophages and the underlying intracellular signal transduction pathways. DBP-maf increased proapoptotic caspase-3, -8, and -9 activities and induced apoptosis in RAW 264.7 cells. However, DBP, the precursor to DBP-maf did not induce apoptosis in these cells. Cell cycle analysis of DBP-maf-treated RAW 264.7 cells revealed growth arrest with accumulation of cells in sub-G(0)/G(1) phase. We also investigated the role of mitogen-activated protein kinase (MAPK) pathways in the DBP-maf-induced apoptosis of RAW264.7 cells. DBP-maf increased the phosphorylation of p38 and JNK1/2, while it decreased the ERK1/2 phosphorylation. Treatment with the p38 MAPK inhibitor, SB202190, attenuated DBP-maf-induced apoptosis. PD98059, a MEK specific inhibitor, did not show a significant inhibition of apoptosis induced by DBP-maf. Taken together, these results suggest that the p38 MAPK pathway plays a crucial role in DBP-maf-mediated apoptosis of macrophages. Our studies indicate that, during inflammation DBP-maf may function positively by causing death of the macrophages when activated macrophages are no longer needed at the site of inflammation. In summary, we report for the first time that DBP-maf induces apoptosis in macrophages via p38 and JNK1/2 pathway. Copyright 2003 Wiley-Liss, Inc.

(+)-Nootkatone inhibits tumor necrosis factor α/interferon γ-induced production of chemokines in HaCaT cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Hyeon-Jae; Lee, Jin-Hwee; Jung, Yi-Sook, E-mail: yisjung@ajou.ac.kr

Highlights: • (+)-Nootkatone inhibits TNF-α/IFN-γ-induced TARC and MDC expression in HaCaT cells. • PKCζ, p38 MAPK, or NF-κB mediate TNF-α/IFN-γ-induced TARC and MDC expression. • (+)-Nootkatone inhibits TNF-α/IFN-γ-induced activation of PKCζ, p38 MAPK, or NF-κB. • (+)-Nootkatone suppresses chemokine expression by inhibiting of PKCζ and p38 pathways. - Abstract: Chemokines are important mediators of cell migration, and thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) are well-known typical inflammatory chemokines involved in atopic dermatitis (AD). (+)-Nootkatone is the major component of Cyperus rotundus. (+)-Nootkatone has antiallergic, anti-inflammatory, and antiplatelet activities. The purpose of this study was to investigate themore » effect of (+)-nootkatone on tumor necrosis factor α (TNF-α)/interferon γ (IFN-γ)-induced expression of Th2 chemokines in HaCaT cells. We found that (+)-nootkatone inhibited the TNF-α/IFN-γ-induced expression of TARC/CCL17 and MDC/CCL22 mRNA in HaCaT cells. It also significantly inhibited TNF-α/IFN-γ-induced activation of nuclear factor kappa B (NF-κB), p38 mitogen-activated protein kinase (MAPK), and protein kinase Cζ (PKCζ). Furthermore, we showed that PKCζ and p38 MAPK contributed to the inhibition of TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression by blocking IκBα degradation in HaCaT cells. Taken together, these results suggest that (+)-nootkatone may suppress TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression in HaCaT cells by inhibiting of PKCζ and p38 MAPK signaling pathways that lead to activation of NF-κB. We propose that (+)-nootkatone may be a useful therapeutic candidate for inflammatory skin diseases such as AD.« less

Ebselen suppresses inflammation induced by Helicobacter pylori lipopolysaccharide via the p38 mitogen-activated protein kinase signaling pathway.

PubMed

Xu, Ling; Gong, Changguo; Li, Guangming; Wei, Jue; Wang, Ting; Meng, Wenying; Shi, Min; Wang, Yugang

2018-05-01

Ebselen is a seleno-organic compound that has been demonstrated to have antioxidant and anti-inflammatory properties. A previous study determined that ebselen inhibits airway inflammation induced by inhalational lipopolysaccharide (LPS), however, the underlying molecular mechanism remains to be elucidated. The present study investigated the effect of ebselen on the glutathione peroxidase (GPX)‑reactive oxygen species (ROS) pathway and interleukin‑8 (IL‑8) expression induced by Helicobacter pylori LPS in gastric cancer (GC) cells. Cells were treated with 200 ng/ml H. pylori‑LPS in the presence or absence of ebselen for various durations and concentrations (µmol/l). The expression of toll‑like receptor 4 (TLR4), GPX2, GPX4, p38 mitogen‑activated protein kinase (p38 MAPK), phosphorylated‑p38 MAPK, ROS production and IL‑8 expression were detected with western blotting or ELISA. The present study revealed that TLR4 expression was upregulated; however, GPX2 and GPX4 expression was reduced following treatment with H. pylori LPS, which led to increased ROS production, subsequently altering the IL‑8 expression level in GC cells. Additionally, it was determined that ebselen prevented the reduction in GPX2/4 levels induced by H. pylori LPS, however, TLR4 expression was not affected. Ebselen may also block the expression of IL‑8 by inhibiting phosphorylation of p38 MAPK. These data suggest ebselen may inhibit ROS production triggered by H. pylori LPS treatment via GPX2/4 instead of TLR4 signaling and reduce phosphorylation of p38 MAPK, resulting in altered production of IL‑8. Ebselen may, therefore, be a potential therapeutic agent to mediate H. pylori LPS-induced cell damage.

Extremely low-level microwaves attenuate immune imbalance induced by inhalation exposure to low-level toluene in mice.

PubMed

Novoselova, Elena G; Glushkova, Olga V; Khrenov, Maxim O; Novoselova, Tatyana V; Lunin, Sergey M; Fesenko, Eugeny E

2017-05-01

To clarify whether extremely low-level microwaves (MW) alone or in combination with p38 inhibitor affect immune cell responses to inhalation exposure of mice to low-level toluene. The cytokine profile, heat shock proteins expression, and the activity of several signal cascades, namely, NF-κB, SAPK/JNK, IRF-3, p38 MAPK, and TLR4 were measured in spleen lymphocytes of mice treated to air-delivered toluene (0.6 mg/m 3 ) or extremely low-level microwaves (8.15-18 GHz, 1μW/cm 2 , 1 Hz swinging frequency) or combined action of these two factors. A single exposure to air-delivered low-level toluene induced activation of NF-κB, SAPK/JNK, IFR-3, p38 MAPK and TLR4 pathways. Furthermore, air toluene induced the expression of Hsp72 and enhanced IL-1, IL-6, and TNF-α in blood plasma, which is indicative of a pro-inflammatory response. Exposure to MW alone also resulted in the enhancement of the plasma cytokine values (e.g. IL-6, TNF-α, and IFN-γ) and activation of the NF-κB, MAPK p38, and especially the TLR4 pathways in splenic lymphocytes. Paradoxically, pre-exposure to MW partially recovered or normalized the lymphocyte parameters in the toluene-exposed mice, while the p38 inhibitor XI additionally increased protective activity of microwaves by down regulating MAPKs (JNK and p38), IKK, as well as expression of TLR4 and Hsp90-α. The results suggest that exposure to low-intensity MW at specific conditions may recover immune parameters in mice undergoing inhalation exposure to low-level toluene via mechanisms involving cellular signaling.

Anti-cancer effects of CME-1, a novel polysaccharide, purified from the mycelia of Cordyceps sinensis against B16-F10 melanoma cells.

PubMed

Jayakumar, Thanasekaran; Chiu, Chong-Chi; Wang, Shwu-Huey; Chou, Duen-Suey; Huang, Yung-Kai; Sheu, Joen-Rong

2014-01-01

Matrix metalloproteinases (MMPs) play important roles in the invasion and migration of cancer cells. In melanoma, several signaling pathways are constitutively activated. Among these, the mitogen-activated protein kinase (MAPKs) signaling pathways are activated through multiple signal transduction molecules and appear to play major roles in melanoma progression. Therefore, the inhibition of MAPK signaling might be a crucial role for the treatment of melanoma cancer. We examined the anticancer effect of CME-1, a novel water-soluble polysaccharide fraction, isolated from Cordyceps sinensis mycelia on B16-F10 melanoma cells. B16-F10 cells were exposed to different concentrations of CME-1 (250, 500 and 800 μg/ml) for 24 h in 5% CO² incubator at 37°C. Western blot analysis was performed to detect the expression of MMP-1, p-p38 MAPK, p-ERK1/2, and IkB-α in B16-F10 cells. Cell migration test was performed by wound healing migration assay. CME-1 suppresses cell migration in a concentration-dependent manner. Western blotting analysis revealed that CME-1 led to the reduction on the expression levels of MMP-1 and down regulated the expression of phosphorylated extracellular signal-regulated kinase (ERK1/2 and p38 mitogen-activated protein kinase (p38 MAPK). CME-1 restored the IkB-degradation in B16F10 cells. These results indicate that CME-1 inhibited MMP-1 expressions in B16F10 melanoma cells through either NF-kB or ERK/p38 MAPK down regulation thereby inhibiting B16F10 cell migration. Therefore, we proposed that CME-1 might be developed as a therapeutic potential candidate for the treatment of cancer metastasis.

Cell-free extracts of Propionibacterium acnes stimulate cytokine production through activation of p38 MAPK and Toll-like receptor in SZ95 sebocytes.

PubMed

Huang, Yu-Chun; Yang, Chao-Hsun; Li, Ting-Ting; Zouboulis, Christos C; Hsu, Han-Chi

2015-10-15

Propionibacterium acnes has been considered to influence the acne lesions. The present study intended to elucidate the underlying signaling pathways of P. acnes in human sebaceous gland cells relative to the generation of proinflammatory cytokines. Cell-free extracts of P. acnes under stationary growth phase were co-incubated with human immortalized SZ95 sebocytes. Then, cell-free P. acnes extracts-induced cytokine expression was evaluated by measuring mRNA and protein levels using quantitative RT-PCR and ELISA. Changes of phosphorylated cell signaling proteins and transcription factors were measured by Western blots and Milliplex assay. The interactive molecular mechanisms of P. acnes and sebocytes were examined through use of shRNA and the specific inhibitors of signaling pathways. Cell-free extracts of P. acnes significantly stimulated secretion of interleukin (IL)-8 and IL-6 in SZ95 sebocytes. The degradation of IκB-α and increased phosphorylation of IκB-α, p38 mitogen activated protein kinase (MAPK), CREB, and STAT3 were demonstrated. Quantitative RT-PCR measurements revealed that gene expression of IL-8 and Toll-like receptor 2 (TLR2) was enhanced by cell-free extracts of P. acnes. In addition, the NF-κB inhibitor BMS345541, p38 MAPK inhibitor SB203580, or anti-TLR2 neutralizing antibody prevented cell-free P. acnes extracts-induced secretion of IL-8. Knockdown of TLR2 using shRNA exerted similar inhibitory effects on IL-8 expression. Moreover, inhibition of STAT3 activity by STA-21 enhanced P. acnes-mediated secretion of IL-8. Cell-free extracts of P. acnes are capable to activate NF-κB and p38 MAPK pathways and up-regulate secretion of IL-8 through TLR2-dependent signaling in human SZ95 sebocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

Amino-modified polystyrene nanoparticles affect signalling pathways of the sea urchin (Paracentrotus lividus) embryos.

PubMed

Pinsino, Annalisa; Bergami, Elisa; Della Torre, Camilla; Vannuccini, Maria Luisa; Addis, Piero; Secci, Marco; Dawson, Kenneth A; Matranga, Valeria; Corsi, Ilaria

2017-03-01

Polystyrene nanoparticles have been shown to pose serious risk to marine organisms including sea urchin embryos based on their surface properties and consequently behaviour in natural sea water. The aim of this study is to investigate the toxicity pathways of amino polystyrene nanoparticles (PS-NH 2 , 50 nm) in Paracentrotus lividus embryos in terms of development and signalling at both protein and gene levels. Two sub-lethal concentrations of 3 and 4 μg/mL of PS-NH 2 were used to expose sea urchin embryos in natural sea water (PS-NH 2 as aggregates of 143 ± 5 nm). At 24 and 48 h post-fertilisation (hpf) embryonic development was monitored and variations in the levels of key proteins involved in stress response and development (Hsp70, Hsp60, MnSOD, Phospho-p38 Mapk) as well as the modulation of target genes (Pl-Hsp70, Pl-Hsp60, Pl-Cytochrome b, Pl-p38 Mapk, Pl-Caspase 8, Pl-Univin) were measured. At 48 hpf various striking teratogenic effects were observed such as the occurrence of cells/masses randomly distributed, severe skeletal defects and delayed development. At 24 hpf a significant up-regulation of Pl-Hsp70, Pl-p38 Mapk, Pl-Univin and Pl-Cas8 genes was found, while at 48 hpf only for Pl-Univin was observed. Protein profile showed different patterns as a significant increase of Hsp70 and Hsp60 only after 48 hpf compared to controls. Conversely, P-p38 Mapk protein significantly increased at 24 hpf and decreased at 48 hpf. Our findings highlight that PS-NH 2 are able to disrupt sea urchin embryos development by modulating protein and gene profile providing new understandings into the signalling pathways involved.

MicroRNA-761 regulates mitochondrial biogenesis in mouse skeletal muscle in response to exercise

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yanli; Zhao, Chaoxian; Sun, Xuewen

MicroRNAs (miRNAs) have been suggested to play critical roles in skeletal muscle in response to exercise. Previous study has shown that miR-761 was involved in a novel model regulating the mitochondrial network. However, its role in mitochondrial biogenesis remains poorly understood. Therefore, the current study was aimed to examine the effect of miR-761 on mitochondrial biogenesis in skeletal muscle. Real-time quantitative PCR analysis demonstrated that aberrantly expressed miR-761 is involved in exercise activity and miR-761 is decreased by exercise training compared with the sedentary control mice. miR-761 suppresses mitochondrial biogenesis of C{sub 2}C{sub 12} myocytes by targeting the 3′-UTR ofmore » peroxisome proliferator-activated receptor gamma (PPARγ) coactivator-1 (PGC-1α). Overexpression of miR-761 was capable of inhibiting the protein expression levels of PGC-1α. Moreover, miR-761 overexpression suppressed the p38 MAPK signaling pathway and down-regulated the expression of phosphorylated MAPK-activated protein kinase-2 (P-MK2), a downstream kinase of p38 MAPK. The phosphorylation of activating transcription factors 2 (ATF2) that plays a functional role in linking the activation of the p38 MAPK pathway to enhanced transcription of the PGC-1α was also inhibited by the overexpression of miR-761. These findings revealed a novel regulation mechanism for miR-761 in skeletal myocytes, and contributed to a better understanding of the modulation of skeletal muscle in response to exercise. - Highlights: • Endurance exercise decreases miR-761 expression in skeletal muscle. • MiR-761 suppresses mitochondrial biogenesis in C{sub 2}C{sub 12} myocytes. • MiR-761 directly targeted PGC-1α expression. • MiR-761 suppresses p38 MAPK signaling pathways in C{sub 2}C{sub 12} myocytes. • A novel mechanism for miR-761 in skeletal myocytes is demonstrated.« less

Aclacinomycin A Sensitizes K562 Chronic Myeloid Leukemia Cells to Imatinib through p38MAPK-Mediated Erythroid Differentiation

PubMed Central

Liu, Fu-Hwa; Huang, Yu-Wen; Huang, Huei-Mei

2013-01-01

Expression of oncogenic Bcr-Abl inhibits cell differentiation of hematopoietic stem/progenitor cells in chronic myeloid leukemia (CML). Differentiation therapy is considered to be a new strategy for treating this type of leukemia. Aclacinomycin A (ACM) is an antitumor antibiotic. Previous studies have shown that ACM induced erythroid differentiation of CML cells. In this study, we investigate the effect of ACM on the sensitivity of human CML cell line K562 to Bcr-Abl specific inhibitor imatinib (STI571, Gleevec). We first determined the optimal concentration of ACM for erythroid differentiation but not growth inhibition and apoptosis in K562 cells. Then, pretreatment with this optimal concentration of ACM followed by a minimally toxic concentration of imatinib strongly induced growth inhibition and apoptosis compared to that with simultaneous co-treatment, indicating that ACM-induced erythroid differentiation sensitizes K562 cells to imatinib. Sequential treatment with ACM and imatinib induced Bcr-Abl down-regulation, cytochrome c release into the cytosol, and caspase-3 activation, as well as decreased Mcl-1 and Bcl-xL expressions, but did not affect Fas ligand/Fas death receptor and procaspase-8 expressions. ACM/imatinib sequential treatment-induced apoptosis was suppressed by a caspase-9 inhibitor and a caspase-3 inhibitor, indicating that the caspase cascade is involved in this apoptosis. Furthermore, we demonstrated that ACM induced erythroid differentiation through the p38 mitogen-activated protein kinase (MAPK) pathway. The inhibition of erythroid differentiation by p38MAPK inhibitor SB202190, p38MAPK dominant negative mutant or p38MAPK shRNA knockdown, reduced the ACM/imatinib sequential treatment-mediated growth inhibition and apoptosis. These results suggest that differentiated K562 cells induced by ACM-mediated p38MAPK pathway become more sensitive to imatinib and result in down-regulations of Bcr-Abl and anti-apoptotic proteins, growth inhibition and apoptosis. These results provided a potential management by which ACM might have a crucial impact on increasing sensitivity of CML cells to imatinib in the differentiation therapeutic approaches. PMID:23613979

Aclacinomycin A sensitizes K562 chronic myeloid leukemia cells to imatinib through p38MAPK-mediated erythroid differentiation.

PubMed

Lee, Yueh-Lun; Chen, Chih-Wei; Liu, Fu-Hwa; Huang, Yu-Wen; Huang, Huei-Mei

2013-01-01

Expression of oncogenic Bcr-Abl inhibits cell differentiation of hematopoietic stem/progenitor cells in chronic myeloid leukemia (CML). Differentiation therapy is considered to be a new strategy for treating this type of leukemia. Aclacinomycin A (ACM) is an antitumor antibiotic. Previous studies have shown that ACM induced erythroid differentiation of CML cells. In this study, we investigate the effect of ACM on the sensitivity of human CML cell line K562 to Bcr-Abl specific inhibitor imatinib (STI571, Gleevec). We first determined the optimal concentration of ACM for erythroid differentiation but not growth inhibition and apoptosis in K562 cells. Then, pretreatment with this optimal concentration of ACM followed by a minimally toxic concentration of imatinib strongly induced growth inhibition and apoptosis compared to that with simultaneous co-treatment, indicating that ACM-induced erythroid differentiation sensitizes K562 cells to imatinib. Sequential treatment with ACM and imatinib induced Bcr-Abl down-regulation, cytochrome c release into the cytosol, and caspase-3 activation, as well as decreased Mcl-1 and Bcl-xL expressions, but did not affect Fas ligand/Fas death receptor and procaspase-8 expressions. ACM/imatinib sequential treatment-induced apoptosis was suppressed by a caspase-9 inhibitor and a caspase-3 inhibitor, indicating that the caspase cascade is involved in this apoptosis. Furthermore, we demonstrated that ACM induced erythroid differentiation through the p38 mitogen-activated protein kinase (MAPK) pathway. The inhibition of erythroid differentiation by p38MAPK inhibitor SB202190, p38MAPK dominant negative mutant or p38MAPK shRNA knockdown, reduced the ACM/imatinib sequential treatment-mediated growth inhibition and apoptosis. These results suggest that differentiated K562 cells induced by ACM-mediated p38MAPK pathway become more sensitive to imatinib and result in down-regulations of Bcr-Abl and anti-apoptotic proteins, growth inhibition and apoptosis. These results provided a potential management by which ACM might have a crucial impact on increasing sensitivity of CML cells to imatinib in the differentiation therapeutic approaches.

Inhibition of curcumin on influenza A virus infection and influenzal pneumonia via oxidative stress, TLR2/4, p38/JNK MAPK and NF-κB pathways.

PubMed

Dai, Jianping; Gu, Liming; Su, Yun; Wang, Qianwen; Zhao, Ying; Chen, Xiaoxua; Deng, Huixiong; Li, Weizhong; Wang, Gefei; Li, Kangsheng

2018-01-01

Oxidative stress, Nrf2-HO-1 and TLR-MAPK/NF-κB signaling pathways have been proved to be involved in influenza A virus (IAV) replication and influenzal pneumonia. In the previous studies, we have performed several high-throughput drug screenings based on the TLR pathways. In the present study, through plaque inhibition test, luciferase reporter assay, TCID 50 , qRT-PCR, western blotting, ELISA and siRNA assays, we investigated the effect and mechanism of action of curcumin against IAV infection in vitro and in vivo. The results showed that curcumin could directly inactivate IAV, blocked IAV adsorption and inhibited IAV proliferation. As for the underlying mechanisms, we found that curcumin could significantly inhibit IAV-induced oxidative stress, increased Nrf2, HO-1, NQO1, GSTA3 and IFN-β production, and suppressed IAV-induced activation of TLR2/4/7, Akt, p38/JNK MAPK and NF-κB pathways. Suppression of Nrf2 via siRNA significantly abolished the stimulatory effect of curcumin on HO-1, NQO1, GSTA3 and IFN-β production and meanwhile blocked the inhibitory effect of curcumin on IAV M2 production. Oxidant H 2 O 2 and TLR2/4, p38/JNK and NF-κB agonists could significantly antagonize the anti-IAV activity of curcumin in vitro. Additionally, curcumin significantly increased the survival rate of mice, reduced lung index, inflammatory cytokines and lung IAV titer, and finally improved pulmonary histopathological changes after IAV infection. In conclusion, curcumin can directly inactivate IAV, inhibits IAV adsorption and replication; and its inhibition on IAV replication may be via activating Nrf2 signal and inhibiting IAV-induced activation of TLR2/4, p38/JNK MAPK and NF-κB pathways. Copyright © 2017 Elsevier B.V. All rights reserved.

Vitamin D protects endothelial cells from irradiation-induced senescence and apoptosis by modulating MAPK/SirT1 axis.

PubMed

Marampon, F; Gravina, G L; Festuccia, C; Popov, V M; Colapietro, E A; Sanità, P; Musio, D; De Felice, F; Lenzi, A; Jannini, E A; Di Cesare, E; Tombolini, V

2016-04-01

Radiotherapy toxicity is related to oxidative stress-mediated endothelial dysfunction. Here, we investigated on radioprotective properties of Vitamin D (Vit.D) on human endothelial cells (HUVEC). HUVEC, pre-treated with Vit.D, were exposed to ionizing radiation (IR): ROS production, cellular viability, apoptosis, senescence and western blot for protein detection were performed. The role of MAPKs pathway was investigated by using U0126 (10 μM) MEKs/ERKs-, SB203580 (2.5 μM) p38-inhibitor or by over/expressing MKK6 p38-upstream activator. Vit.D reduced IR-induced ROS production protecting proliferating and quiescent HUVEC from cellular apoptosis or senescence, respectively, by regulating MAPKs pathways. In proliferating HUVEC, Vit.D prevented IR-induced apoptosis by activating ERKs while in quiescent HUVEC counteracted IR-induced senescence by inhibiting the p38-IR-induced activation. MEKs&ERKs inhibition in proliferating or MKK6/mediated p38 activation in quiescent HUVEC, respectively, reverted anti-apoptotic or anti-senescent Vit.D properties. SirT1 protein expression levels were up-regulated by Vit.D. ERKs inhibition blocked Vit.D-induced SirT1 protein up-regulation in proliferating cells. In quiescent HUVEC cells, p38 inhibition counteracted the IR-induced SirT1 protein down-regulation, while MKK6 transfection abrogated the Vit.D positive effects on SirT1 protein levels after irradiation. SirT1 inhibition by sirtinol blocked the Vit.D radioprotective effects. Vit.D protects HUVEC from IR induced/oxidative stress by positively regulating the MAPKs/SirT1 axis.

Pirfenidone Induces G1 Arrest in Human Tenon's Fibroblasts In Vitro Involving AKT and MAPK Signaling Pathways.

PubMed

Guo, Xiujuan; Yang, Yangfan; Liu, Liling; Liu, Xiaoan; Xu, Jiangang; Wu, Kaili; Yu, Minbin

2017-06-01

To investigate the underlying mechanism by which pirfenidone blocks the transition from the G1 to S phase in primary human Tenon's fibroblasts. Primary human Tenon's fibroblasts were characterized by immunocytofluorescence staining with vimentin, fibroblast surface protein, and cytokeratin. After treating Tenon's fibroblasts with pirfenidone under proliferation conditions (10% fetal bovine serum), cell proliferation was measured using a WST-1 assay. Progression through the cell cycle was analyzed by flow cytometry. The expression of CDK2, CDK6, cyclinD1, cyclinD3, and cyclinE and the phosphorylation of AKT, ERK1/2/MAPK, JNK/MAPK, and p38 MAPK were estimated using western blot analysis. Under proliferative conditions, pirfenidone inhibited Tenon's fibroblasts proliferation and arrested the cell cycle at the G1 phase; decreased the phosphorylation of AKT, GSK3β, ERK1/2/MAPK, and JNK/MAPK; increased the phosphorylation of p38 MAPK; and inhibited CDK2, CDK6, cyclin D1, cyclin D3, and cyclin E in a dose-dependent manner. Inhibitors of AKT (LY294002), ERK1/2 (U0126), and JNK (SP600125) arrested the G1/S transition, similar to the effect of pirfenidone. The p38 inhibitor (SB202190) decreased the G1-blocking effect of pirfenidone. The expression of CDK2, CDK6, cyclin D1, and cyclin D3 were inhibited by LY294002, U0126, and SP600125. SB202190 attenuated the pirfenidone-induced reduction of CDK2, CDK6, cyclin D1, cyclin D3, and cyclin E. Pirfenidone inhibited HTFs proliferation and induced G1 arrest by downregulating CDKs and cyclins involving the AKT/GSK3β and MAPK signaling pathways.

B7-H3 Augments Inflammatory Responses and Exacerbates Brain Damage via Amplifying NF-κB p65 and MAPK p38 Activation during Experimental Pneumococcal Meningitis

PubMed Central

Chen, Xuqin; Li, Yan; Blankson, Siobhan; Liu, Min; Huang, Danping; Redmond, H. Paul; Huang, Jing; Wang, Jiang Huai; Wang, Jian

2017-01-01

The costimulatory protein B7-H3 has been shown to play a contributory role in the development and progression of experimental pneumococcal meningitis by augmentation of the innate immunity-associated inflammatory response via a TLR2-dependent manner. This study aimed to clarify the component(s) of TLR2-mediated signal transduction pathways responsible for B7-H3-augmented inflammatory response and subsequent brain damage during experimental pneumococcal meningitis. Administration of B7-H3 did not augment expression of TLR2 and other TLR2 upstream components, but led to an enhanced formation of MyD88-IRAK immunocomplex in the brain of S. pneumoniae-infected mice. Furthermore, B7-H3 substantially augmented S. pneumoniae-induced activation of TLR2 downstream NF-κB p65 and MAPK p38 pathways in the brain of S. pneumoniae-infected mice. Notably, blockage of NF-κB p65 and/or MAPK p38 with their specific inhibitors strongly attenuated B7-H3-amplified inflammatory response with significantly reduced proinflammatory cytokine and chemokine production, and markedly ameliorated B7-H3-exacerbated disruption of blood-brain barrier and severity of disease status in S. pneumoniae-infected mice. These results indicate that targeting NF-κB p65 and/or MAPK p38 may represent a promising therapeutic option for amelioration of overwhelming inflammatory response-associated brain injury frequently observed during pneumococcal meningitis. PMID:28141831

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimura, Hideki, E-mail: hkimura@u-fukui.ac.jp; Department of Clinical Laboratories and Nephrology, University of Fukui Hospital, Fukui; Mikami, Daisuke

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

Double-Stranded RNA-Dependent Protein Kinase Regulates the Motility of Breast Cancer Cells

PubMed Central

Xu, Mei; Chen, Gang; Wang, Siying; Liao, Mingjun; Frank, Jacqueline A.; Bower, Kimberly A.; Zhang, Zhuo; Shi, Xianglin; Luo, Jia

2012-01-01

Double-stranded RNA (dsRNA)-dependent protein kinase (PKR) is an interferon-induced protein kinase that plays a central role in the anti-viral process. Due to its pro-apoptotic and anti-proliferative action, there is an increased interest in PKR modulation as an anti-tumor strategy. PKR is overexpressed in breast cancer cells; however, the role of PKR in breast cancer cells is unclear. The expression/activity of PKR appears inversely related to the aggressiveness of breast cancer cells. The current study investigated the role of PKR in the motility/migration of breast cancer cells. The activation of PKR by a synthesized dsRNA (PIC) significantly decreased the motility of several breast cancer cell lines (BT474, MDA-MB231 and SKBR3). PIC inhibited cell migration and blocked cell membrane ruffling without affecting cell viability. PIC also induced the reorganization of the actin cytoskeleton and impaired the formation of lamellipodia. These effects of PIC were reversed by the pretreatment of a selective PKR inhibitor. PIC also activated p38 mitogen-activated protein kinase (MAPK) and its downstream MAPK-activated protein kinase 2 (MK2). PIC-induced activation of p38 MAPK and MK2 was attenuated by the PKR inhibitor and the PKR siRNA, but a selective p38 MAPK inhibitor (SB203580) or other MAPK inhibitors did not affect PKR activity, indicating that PKR is upstream of p38 MAPK/MK2. Cofilin is an actin severing protein and regulates membrane ruffling, lamellipodia formation and cell migration. PIC inhibited cofilin activity by enhancing its phosphorylation at Ser3. PIC activated LIM kinase 1 (LIMK1), an upstream kinase of cofilin in a p38 MAPK-dependent manner. We concluded that the activation of PKR suppressed cell motility by regulating the p38 MAPK/MK2/LIMK/cofilin pathway. PMID:23112838

PLCγ2 promotes apoptosis while inhibits proliferation in rat hepatocytes through PKCD/JNK MAPK and PKCD/p38 MAPK signalling.

PubMed

Chen, Xiaoguang; Lv, Qiongxia; Ma, Jun; Liu, Yumei

2018-02-11

The PLCG2 (PLCγ2) gene is a member of PLC gene family encoding transmembrane signalling enzymes involved in various biological processes including cell proliferation and apoptosis. Our earlier study indicated that PLCγ2 may be involved in the termination of regeneration of the liver which is mainly composed of hepatocytes, but its exact biological function and molecular mechanism in liver regeneration termination remains unclear. This study aims to examine the role of PLCγ2 in the growth of hepatocytes. A recombinant adenovirus expressing PLCγ2 was used to infect primary rat hepatocytes. PLCγ2 mRNA and protein levels were detected by qRT-PCR and Western blot. The subcellular location of PLCγ2 protein was tested by an immunofluorescence assay. The proliferation of hepatocytes was measured by MTT assay. The cell cycle and apoptosis were analysed by flow cytometry. Caspase-3, -8 and -9 activities were measured by a spectrophotometry method. Phosphorylation levels of PKCD, JNK and p38 in the infected cells were detected by Western blot. The possible mechanism underlying the role of PLCγ2 in hepatocyte growth was also explored by adding a signalling pathway inhibitor. Hepatocyte proliferation was dramatically reduced, while cell apoptosis was remarkably increased. The results demonstrated that PLCγ2 increased the phosphorylation of PKCD, p38 and JNK in rat hepatocytes. After PKCD activity was inhibited by the inhibitor Go 6983, the levels of both p-p38 and p-JNK MAPKs significantly decreased, and PLCγ2-induced cell proliferation inhibition and cell apoptosis were obviously reversed. This study showed that PLCγ2 regulates hepatocyte growth through PKCD-dependently activating p38 MAPK and JNK MAPK pathways; this result was experimentally based on the further exploration of the effect of PLCγ2 on hepatocyte growth in vivo. © 2018 John Wiley & Sons Ltd.

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

PubMed

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

2014-07-01

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

Down-Regulation of AQP4 Expression via p38 MAPK Signaling in Temozolomide-Induced Glioma Cells Growth Inhibition and Invasion Impairment.

PubMed

Chen, Yuqin; Gao, Fei; Jiang, Rong; Liu, Hui; Hou, Jiaojiao; Yi, Yaoxing; Kang, Lili; Liu, Xueyuan; Li, Yuan; Yang, Mei

2017-12-01

Glioma is the most common and lethal central nervous system tumors. Temozolomide (TMZ) is an effective drug for malignant glioma, however, the intracellular and molecular mechanisms behind this anti-cancer effect have yet to be fully understood. The aim of the present study was to determine whether TMZ inhibits proliferation, invasion of glioma cells in vitro and whether these effects can be mediated through modulation of aquaporin 4 (AQP4) and phosphorylation of the MAPK pathway. The viability of U87 and U251 human glioma cells was evaluated using MTT assay. The cell cycle distribution was detected with flow cytometry. Migration ability and invasion ability were tested by scratch assays and transwell assays, respectively. The levels of AQP4 and MAPK were measured using immunoblot analyses. Our results showed that TMZ inhibited proliferation, migration and invasion, and induced G2/M arrest in U87 and U251 glioma cell lines. These changes were associated with a decrease in the levels of AQP4 expression as well as activation phosphorylated level of p38. Treatment with a p38 chemical activator (anisomycin) resulted in similar effects as TMZ treatment on glioma cells. And p38 chemical inhibitor (SB203580) could block these effects in glioma treated with TMZ, suggesting a direct up-regulation of the p38 signaling pathway. Therefore, we identified that TMZ might have therapeutic potential for controlling proliferation, invasion of malignant glioma by inhibiting AQP4 expression through activation of p38 signal transduction pathway. J. Cell. Biochem. 118: 4905-4913, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

A coordinated phosphorylation cascade initiated by p38MAPK/MSK1 directs RARα to target promoters

PubMed Central

Bruck, Nathalie; Vitoux, Dominique; Ferry, Christine; Duong, Vanessa; Bauer, Annie; de Thé, Hughes; Rochette-Egly, Cécile

2009-01-01

The nuclear retinoic acid (RA) receptor alpha (RARα) is a transcriptional transregulator that controls the expression of specific gene subsets through binding at response elements and dynamic interactions with coregulators, which are coordinated by the ligand. Here, we highlighted a novel paradigm in which the transcription of RARα target genes is controlled by phosphorylation cascades initiated by the rapid RA activation of the p38MAPK/MSK1 pathway. We demonstrate that MSK1 phosphorylates RARα at S369 located in the ligand-binding domain, allowing the binding of TFIIH and thereby phosphorylation of the N-terminal domain at S77 by cdk7/cyclin H. MSK1 also phosphorylates histone H3 at S10. Finally, the phosphorylation cascade initiated by MSK1 controls the recruitment of RARα/TFIIH complexes to response elements and subsequently RARα target gene activation. Cancer cells characterized by a deregulated p38MAPK/MSK1 pathway, do not respond to RA, outlining the essential contribution of the RA-triggered phosphorylation cascade in RA signalling. PMID:19078967

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

CXCL1 inhibits airway smooth muscle cell migration through the decoy receptor Duffy antigen receptor for chemokines.

PubMed

Al-Alwan, Laila A; Chang, Ying; Rousseau, Simon; Martin, James G; Eidelman, David H; Hamid, Qutayba

2014-08-01

Airway smooth muscle cell (ASMC) migration is an important mechanism postulated to play a role in airway remodeling in asthma. CXCL1 chemokine has been linked to tissue growth and metastasis. In this study, we present a detailed examination of the inhibitory effect of CXCL1 on human primary ASMC migration and the role of the decoy receptor, Duffy AgR for chemokines (DARC), in this inhibition. Western blots and pathway inhibitors showed that this phenomenon was mediated by activation of the ERK-1/2 MAPK pathway, but not p38 MAPK or PI3K, suggesting a biased selection in the signaling mechanism. Despite being known as a nonsignaling receptor, small interference RNA knockdown of DARC showed that ERK-1/2 MAPK activation was significantly dependent on DARC functionality, which, in turn, was dependent on the presence of heat shock protein 90 subunit α. Interestingly, DARC- or heat shock protein 90 subunit α-deficient ASMCs responded to CXCL1 stimulation by enhancing p38 MAPK activation and ASMC migration through the CXCR2 receptor. In conclusion, we demonstrated DARC's ability to facilitate CXCL1 inhibition of ASMC migration through modulation of the ERK-1/2 MAPK-signaling pathway. Copyright © 2014 by The American Association of Immunologists, Inc.

Tanshinone IIA inhibits AGEs-induced proliferation and migration of cultured vascular smooth muscle cells by suppressing ERK1/2 MAPK signaling.

PubMed

Lu, Ming; Luo, Ying; Hu, Pengfei; Dou, Liping; Huang, Shuwei

2018-01-01

Vascular smooth muscle cells (VSMCs) play a key role in the pathogenesis of diabetic vascular disease. Our current study sought to explore the effects of tanshinone IIA on the proliferation and migration of VSMCs induced by advanced glycation end products (AGEs). In this study, we examined the effects of tanshinone IIA by cell proliferation assay and cell migration assay. And we explored the underlying mechanism by Western blotting. AGEs significantly induced the proliferation and migration of VSMCs, but treatment with tanshinone IIA attenuated these effects. AGEs could increase the activity of the ERK1/2 and p38 pathways but not the JNK pathway. Treatment with tanshinone IIA inhibited the AGEs-induced activation of the ERK1/2 pathway but not the p38 pathway. Tanshinone IIA inhibits AGEs-induced proliferation and migration of VSMCs by suppressing the ERK1/2 MAPK signaling pathway.

Ghrelin accelerates wound healing through GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways in combined radiation and burn injury in rats.

PubMed

Liu, Cong; Huang, Jiawei; Li, Hong; Yang, Zhangyou; Zeng, Yiping; Liu, Jing; Hao, Yuhui; Li, Rong

2016-06-07

The therapeutic effect of ghrelin on wound healing was assessed using a rat model of combined radiation and burn injury (CRBI). Rat ghrelin, anti-rat tumor necrosis factor (TNF) α polyclonal antibody (PcAb), or selective antagonists of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), and growth hormone secretagogue receptor (GHS-R) 1a (SB203580, SP600125, and [D-Lys3]-GHRP-6, respectively), were administered for seven consecutive days. Levels of various signaling molecules were assessed in isolated rat peritoneal macrophages. The results showed that serum ghrelin levels and levels of macrophage glucocorticoid receptor (GR) decreased, while phosphorylation of p38MAPK, JNK, and p65 nuclear factor (NF) κB increased. Ghrelin inhibited the serum induction of proinflammatory mediators, especially TNF-α, and promoted wound healing in a dose-dependent manner. Ghrelin treatment decreased phosphorylation of p38MAPK, JNK, and p65NF-κB, and increased GR levels in the presence of GHS-R1a. SB203580 or co-administration of SB203580 and SP600125 decreased TNF-α level, which may have contributed to the inactivation of p65NF-κB and increase in GR expression, as confirmed by western blotting. In conclusion, ghrelin enhances wound recovery in CRBI rats, possibly by decreasing the induction of TNF-α or other proinflammatory mediators that are involved in the regulation of GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways.

Targeting p38 Mitogen-Activated Protein Kinase Signaling Restores Subventricular Zone Neural Stem Cells and Corrects Neuromotor Deficits in Atm Knockout Mouse

PubMed Central

Kim, Jeesun

2012-01-01

Ataxia-telangiectasia (A-T) is a progressive degenerative disorder that results in major neurological disability. In A-T patients, necropsy has revealed atrophy of cerebellar cortical layers along with Purkinje and granular cell loss. We have previously identified an oxidative stress-mediated increase in phospho-p38 mitogen-activated protein kinase (MAPK) and the resultant downregulation of Bmi-1 and upregulation of p21 as key components of the mechanism causing defective proliferation of neural stem cells (NSCs) isolated from the subventricular zone (SVZ) of Atm−/− mice. However, the in vivo aspect of alteration in SVZ tissue and the functional significance of p38MAPK activation in NSCs for neuropathogenesis of ATM deficiency remain unknown. Here we show that the NSC population was abnormally decreased in the SVZ of 3-month-old Atm−/− mice; this decrease was accompanied by p38MAPK activation. However, after a 2-month treatment with the p38MAPK inhibitor SB203580, starting at 1 month old, Atm−/− mice showed restoration of normal levels of Bmi-1 and p21 with the rescue of NSC population in the SVZ. In addition, treated Atm−/− mice exhibited more Purkinje cells in the cerebellum. Most importantly, motor coordination of Atm−/− mice was significantly improved in the treatment group. Our results show for the first time in vivo evidence of depleted NSCs in the SVZ of Atm−/− mice and also demonstrate that pharmacologic inhibition of p38MAPK signaling has the potential to treat neurological defects of A-T. This study provides a promising approach targeting the oxidative stress-dependent p38 signaling pathway not only for A-T but also for other neurodegenerative disorders. PMID:23197859

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. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Serk In, E-mail: serkin@korea.edu; The BK21 Plus Program for Biomedical Sciences, Korea University College of Medicine, Seoul; Department of Medicine and Center for Bone Biology, Vanderbilt University School of Medicine, Nashville, TN

The radiation stress induces cytotoxic responses of cell death as well as cytoprotective responses of cell survival. Understanding exact cellular mechanism and signal transduction pathways is important in improving cancer radiotherapy. Increasing evidence suggests that cyclic AMP response element binding protein (CREB)/activating transcription factor (ATF) family proteins act as a survival factor and a signaling molecule in response to stress. We postulated that CREB inhibition via CRE decoy oligonucleotide increases tumor cell sensitization to γ-irradiation-induced cytotoxic stress. In the present study, we demonstrate that CREB phosphorylation and CREB DNA-protein complex formation increased in time- and radiation dose-dependent manners, while theremore » was no significant change in total protein level of CREB. In addition, CREB was phosphorylated in response to γ-irradiation through p38 MAPK pathway. Further investigation revealed that CREB blockade by decoy oligonucleotides functionally inhibited transactivation of CREB, and significantly increased radiosensitivity of multiple human cancer cell lines including TP53- and/or RB-mutated cells with minimal effects on normal cells. We also demonstrate that tumor cells ectopically expressing dominant negative mutant CREB (KCREB) and the cells treated with p38 MAPK inhibitors were more sensitive to γ-irradiation than wild type parental cells or control-treated cells. Taken together, we conclude that CREB protects tumor cells from γ-irradiation, and combination of CREB inhibition plus ionizing radiation will be a promising radiotherapeutic approach. - Highlights: • γ-Irradiation induced CREB phosphorylation and CRE-directed transcription in tumor. • γ-Irradiation-induced transcriptional activation of CREB was via p38 MAPK pathway. • CRE blockade increased radiosensitivity of tumor cells but not of normal cells. • CRE decoy oligonucleotides or p38 MAPK inhibitors can be used as radiosensitizers.« less

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

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.

Mitogen-activated protein kinase signaling pathways promote low-density lipoprotein receptor-related protein 1-mediated internalization of beta-amyloid protein in primary cortical neurons.

PubMed

Yang, Wei-Na; Ma, Kai-Ge; Qian, Yi-Hua; Zhang, Jian-Shui; Feng, Gai-Feng; Shi, Li-Li; Zhang, Zhi-Chao; Liu, Zhao-Hui

2015-07-01

Mounting evidence suggests that the pathological hallmarks of Alzheimer's disease (AD) are caused by the intraneuronal accumulation of beta-amyloid protein (Aβ). Reuptake of extracellular Aβ is believed to contribute significantly to the intraneuronal Aβ pool in the early stages of AD. Published reports have claimed that the low-density lipoprotein receptor-related protein 1 (LRP1) mediates Aβ1-42 uptake and lysosomal trafficking in GT1-7 neuronal cells and mouse embryonic fibroblast non-neuronal cells. However, there is no direct evidence supporting the role of LRP1 in Aβ internalization in primary neurons. Our recent study indicated that p38 MAPK and ERK1/2 signaling pathways are involved in regulating α7 nicotinic acetylcholine receptor (α7nAChR)-mediated Aβ1-42 uptake in SH-SY5Y cells. This study was designed to explore the regulation of MAPK signaling pathways on LRP1-mediated Aβ internalization in neurons. We found that extracellular Aβ1-42 oligomers could be internalized into endosomes/lysosomes and mitochondria in cortical neurons. Aβ1-42 and LRP1 were also found co-localized in neurons during Aβ1-42 internalization, and they could form Aβ1-42-LRP1 complex. Knockdown of LRP1 expression significantly decreased neuronal Aβ1-42 internalization. Finally, we identified that p38 MAPK and ERK1/2 signaling pathways regulated the internalization of Aβ1-42 via LRP1. Therefore, these results demonstrated that LRP1, p38 MAPK and ERK1/2 mediated the internalization of Aβ1-42 in neurons and provided evidence that blockade of LRP1 or inhibitions of MAPK signaling pathways might be a potential approach to lowering brain Aβ levels and served a potential therapeutic target for AD. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kook, Sung-Ho; Lim, Shin-Saeng; Cho, Eui-Sic

2014-12-12

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

p38 mitogen-activated protein kinase up-regulates NF-{kappa}B transcriptional activation through RelA phosphorylation during stretch-induced myogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ji, Guoping; Liu, Dongxu; Liu, Jing

2010-01-01

p38 MAPK and nuclear factor-B (NF-B) signaling pathways play an indispensable role in the control of skeletal myogenesis. The specific contribution of these signaling pathways to the response of myoblast to the mechanical stimulation and the molecular mechanisms underlying this response remain unresolved. Using an established in vitro model, we now show that p38 MAP kinase activity regulates the transcriptional activation of NF-{kappa}B in response to mechanical stimulation of myoblasts. Furthermore, SB203580 blocked stretch-induced NF-{kappa}B activation during myogenesis, not through down-regulation of degradation of I{kappa}B-{alpha}, and consequent translocation of the p65 subunit of NF-{kappa}B to the nucleus. It is likelymore » that stretch-induced NF-{kappa}B activation by phosphorylation of p65 NF-{kappa}B. Moreover, depletion of p38{alpha} using siRNA significantly reduces stretch-induced phosphorylation of RelA and NF-{kappa}B activity. These results provides the first evidence of a cross-talk between p38 MAPK and NF-{kappa}B signaling pathways during stretch-induced myogenesis, with phosphorylation of RelA being one of the effectors of this promyogenic mechanism. The {alpha} isoform of p38MAP kinase regulates the transcriptional activation of NF-{kappa}B following stimulation with cyclic stretch.« less

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

PubMed

Min, Jie; Huang, Kenan; Tang, Hua; Ding, Xinyu; Qi, Chen; Qin, Xiong; Xu, Zhifei

2015-12-01

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

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

PubMed Central

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

2015-01-01

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

Carprofen induction of p75NTR-dependent apoptosis via the p38 mitogen-activated protein kinase pathway in prostate cancer cells.

PubMed

Khwaja, Fatima S; Quann, Emily J; Pattabiraman, Nagarajan; Wynne, Shehla; Djakiew, Daniel

2008-11-01

The p75 neurotrophin receptor (p75(NTR)) functions as a tumor suppressor in prostate epithelial cells, where its expression declines with progression to malignant cancer. Previously, we showed that treatment with R-flurbiprofen or ibuprofen induced p75(NTR) expression in several prostate cancer cell lines leading to p75(NTR)-mediated decreased survival. Using the 2-phenyl propionic acid moiety of these profens as a pharmacophore, we screened an in silico database of 30 million compounds and identified carprofen as having an order of magnitude greater activity for induction of p75(NTR) levels and inhibition of cell survival. Prostate (PC-3 and DU-145) and bladder (T24) cancer cells were more sensitive to carprofen induction of p75(NTR)-associated loss of survival than breast (MCF-7) and fibroblast (3T3) cells. Transfection of prostate cell lines with a dominant-negative form of p75(NTR) before carprofen treatment partially rescued cell survival, showing a cause-and-effect relationship between carprofen induction of p75(NTR) levels and inhibition of survival. Carprofen induced apoptotic nuclear fragmentation in prostate but not in MCF-7 and 3T3 cells. Furthermore, small interfering RNA knockdown of the p38 mitogen-activated protein kinase (MAPK) protein prevented induction of p75(NTR) by carprofen in both prostate cell lines. Carprofen treatment induced phosphorylation of p38 MAPK as early as within 1 min. Expression of a dominant-negative form of MK2, the kinase downstream of p38 MAPK frequently associated with signaling cascades leading to apoptosis, prevented carprofen induction of the p75(NTR) protein. Collectively, we identify carprofen as a highly potent profen capable of inducing p75(NTR)-dependent apoptosis via the p38 MAPK pathway in prostate cancer cells.

Non-Smad signaling pathways.

PubMed

Mu, Yabing; Gudey, Shyam Kumar; Landström, Maréne

2012-01-01

Transforming growth factor-beta (TGFβ) is a key regulator of cell fate during embryogenesis and has also emerged as a potent driver of the epithelial-mesenchymal transition during tumor progression. TGFβ signals are transduced by transmembrane type I and type II serine/threonine kinase receptors (TβRI and TβRII, respectively). The activated TβR complex phosphorylates Smad2 and Smad3, converting them into transcriptional regulators that complex with Smad4. TGFβ also uses non-Smad signaling pathways such as the p38 and Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathways to convey its signals. Ubiquitin ligase tumor necrosis factor (TNF)-receptor-associated factor 6 (TRAF6) and TGFβ-associated kinase 1 (TAK1) have recently been shown to be crucial for the activation of the p38 and JNK MAPK pathways. Other TGFβ-induced non-Smad signaling pathways include the phosphoinositide 3-kinase-Akt-mTOR pathway, the small GTPases Rho, Rac, and Cdc42, and the Ras-Erk-MAPK pathway. Signals induced by TGFβ are tightly regulated and specified by post-translational modifications of the signaling components, since they dictate the subcellular localization, activity, and duration of the signal. In this review, we discuss recent findings in the field of TGFβ-induced responses by non-Smad signaling pathways.

Evidence for the Involvement of p38 MAPK Activation in Barnacle Larval Settlement

PubMed Central

He, Li-Sheng; Xu, Ying; Matsumura, Kiyotaka; Zhang, Yu; Zhang, Gen; Qi, Shu-Hua; Qian, Pei-Yuan

2012-01-01

The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila and humans. The activation of p38 MAPK was detected by an antibody that recognizes the conserved dual phosphorylation sites of TGY. The results showed that phospho-p38 MAPK (pp38 MAPK) was more highly expressed at the cyprid stage, particularly in aged cyprids, in comparison to other stages, including the nauplius and juvenile stages. Immunostaining showed that Bar-p38 MAPK and pp38 MAPK were mainly located at the cyprid antennules, and especially the third and fourth segments, which are responsible for substratum exploration during settlement. The expression and localization patterns of Bar-p38 MAPK suggest its involvement in larval settlement. This postulation was also supported by the larval settlement bioassay with the p38 MAPK inhibitor SB203580. Behavioral analysis by live imaging revealed that the larvae were still capable of exploring the surface of the substratum after SB203580 treatment. This shows that the effect of p38 MAPK on larval settlement might be by regulating the secretion of permanent proteinaceous substances. Furthermore, the level of pp38 MAPK dramatically decreased after full settlement, suggesting that Bar-p38 MAPK maybe plays a role in larval settlement rather than metamorphosis. Finally, we found that Bar-p38 MAPK was highly activated when larvae confronted extracts of adult barnacle containing settlement cues, whereas larvae pre-treated with SB203580 failed to respond to the crude adult extracts. PMID:23115639

Mechanisms of TNFalpha-induced cardiac dysfunction in cholestatic bile duct-ligated mice: interaction between TNFalpha and endocannabinoids.

PubMed

Yang, Ying-Ying; Liu, Hongqun; Nam, Soon Woo; Kunos, George; Lee, Samuel S

2010-08-01

Chronic liver disease is associated with endotoxemia, oxidative stress, increased endocannabinoids and decreased cardiac responsiveness. Endocannabinoids activate the tumor necrosis factor-alpha (TNFalpha)-nuclear factor kappaB (NFkappaB) pathway. However, how they interact with each other remains obscure. We therefore aimed to clarify the relationship between the TNFalpha-NFkappaB pathway and endocannabinoids in the pathogenesis of cardiodepression of cholestatic bile duct ligated (BDL) mice. BDL mice with TNFalpha knockout (TNFalpha-/-) and infusion of anti-TNFalpha antibody were used. Cardiac mRNA and protein expression of NFkappaBp65, c-Jun-N-terminal kinases (JNK), p38 mitogen-activated protein kinase (p38MAPK), extracelullar-signal- regulated kinase (ERK), inducible nitric oxide synthase (iNOS), Copper/Zinc and Magnesium-superoxide dismutase (Cu/ Zn- and Mn-SOD), cardiac anandamide, 2-arachidonoylglycerol (2-AG), nitric oxide (NOx) and glutathione, and plasma TNFalpha were measured. The effects of TNFalpha, cannabinoid receptor (CB1) antagonist AM251 and the endocannabinoid reuptake inhibitor UCM707, on the contractility of isolated cardiomyocytes, were assessed. In BDL mice, cardiac mRNA and protein expression of NFkappaBp65, p38MAPK, iNOS, NOx, anandamide, and plasma TNFa were increased, whereas glutathione, Cu/Zn-SOD, and Mn-SOD were decreased. Cardiac contractility was blunted in BDL mice. Anti-TNFa treatment in BDL mice decreased cardiac anandamide and NOx, reduced expression of NFkappaBp65, p38MAPK, and iNOS, enhanced expression of Cu/Zn-SOD and Mn-SOD, increased reductive glutathione and restored cardiomyocyte contractility. TNFa-depressed contractility was worsened by UCM707, whereas AM251 improved contractility. Increased TNFalpha, acting via NFkappaB-iNOS and p38MAPK signaling pathways, plays an important role in the pathogenesis of cardiodepression in BDL mice. TNFalpha also suppressed contractility by increasing oxidative stress and endocannabinoid activity.

Curcumin attenuates chronic intermittent hypoxia-induced brain injuries by inhibiting AQP4 and p38 MAPK pathway.

PubMed

Wang, Bo; Li, Wenyang; Jin, Hongyu; Nie, Xinshi; Shen, Hui; Li, Erran; Wang, Wei

2018-09-01

Chronic intermittent hypoxia (CIH) is one of the main features of obstructive sleep apnea (OSA), which is also commonly associated with neurocognitive impairments. The present study aimed to elucidate the beneficial effect of curcumin on CIH-induced brain injuries. Male balb/c mice (6 ∼ 8 weeks) were exposed to normoxia or a pattern of CIH (8 h/day, cycles of 180 s each, hypoxia: 5% O 2 for 50 s, reoxygenation: 21% O 2 for 50 s) for 10 weeks, along with daily curcumin treatment (50, 100, or 200 mg/kg, intragastrically) or its vehicle. The results showed that CIH induced significant brain edema, as well as neuronal apoptosis and astrogliosis in the cerebral cortex, brainstem, and cerebellum regions of brain. In addition, increased astrocytic AQP4 expression and activation of p38 MAPK pathway were observed after CIH exposure. Curcumin dose-dependently mitigated the brain edema and relevant cell alterations, showing a neuroprotective effect in CIH-induced brain injury. Together, these results suggest curcumin ameliorates the CIH-induced brain injuries, including brain edema, neuronal death and astrogliosis. The beneficial role of curcumin is mediated partially by regulating AQP4 and p38 MAPK pathway. Copyright © 2018 Elsevier B.V. All rights reserved.

p38 MAPK mediates fibrogenic signal through Smad3 phosphorylation in rat myofibroblasts.

PubMed

Furukawa, Fukiko; Matsuzaki, Koichi; Mori, Shigeo; Tahashi, Yoshiya; Yoshida, Katsunori; Sugano, Yasushi; Yamagata, Hideo; Matsushita, Masanori; Seki, Toshihito; Inagaki, Yutaka; Nishizawa, Mikio; Fujisawa, Junichi; Inoue, Kyoichi

2003-10-01

Hepatic stellate cells (HSCs) spontaneously transdifferentiate into myofibroblast (MFB)-phenotype on plastic dishes. This response recapitulates the features of activation in vivo. Transforming growth factor beta (TGF-beta) plays a prominent role in stimulating liver fibrogenesis by MFBs. In quiescent HSCs, TGF-beta signaling involves TGF-beta type I receptor (TbetaRI)-mediated phosphorylation of serine residues within the conserved SSXS motif at the C-terminus of Smad2 and Smad3. The middle linker regions of Smad2 and Smad3 also are phosphorylated by mitogen-activated protein kinase (MAPK). This study elucidates the change of Smad3-mediated signals during the transdifferentiation process. By using antibodies highly specific to the phosphorylated C-terminal region and the phosphorylated linker region of Smad3, we found that TGF-beta-dependent Smad3 phosphorylation at the C-terminal region decreased, but that the phosphorylation at the linker region increased in the process of transdifferentiation. TGF-beta activated the p38 MAPK pathway, further leading to Smad3 phosphorylation at the linker region in the cultured MFBs, irrespective of Smad2. The phosphorylation promoted hetero-complex formation and nuclear translocation of Smad3 and Smad4. Once combined with TbetaRI-phosphorylated Smad2, the Smad3 and Smad4 complex bound to plasminogen activator inhibitor-type I promoter could enhance the transcription. In addition, Smad3 phosphorylation mediated by the activated TbetaRI was impaired severely in MFBs during chronic liver injury, whereas Smad3 phosphorylation at the linker region was remarkably induced by p38 MAPK pathway. In conclusion, p38 MAPK-dependent Smad3 phosphorylation promoted extracellular matrix production in MFBs both in vitro and in vivo.

NMDA receptor dependent PGC-1alpha up-regulation protects the cortical neuron against oxygen-glucose deprivation/reperfusion injury.

PubMed

Luo, Yun; Zhu, Wenjing; Jia, Jia; Zhang, Chenyu; Xu, Yun

2009-09-01

The peroxisome proliferator activated receptor coactivator 1 alpha (PGC-1alpha) is a nuclear transcriptional coactivator that is widely expressed in the brain areas. Over-expression of PGC-1alpha can protect neuronal cells from oxidant-induced injury. The purpose of the current study is to investigate the role of PGC-1alpha in the oxygen (anoxia) deprivation (OGD) neurons. The PGC-1alpha mRNA and protein level between control and OGD neurons were examined by real-time PCR and Western blot. More PGC-1alpha expression was found in the OGD neurons compared with the normal group. Over-expression of PGC-1alpha suppressed cell apoptosis while inhibition of the PGC-1alpha expression induced cell apoptosis in OGD neurons. Furthermore, increase of PGC-1alpha resulted in activation of N-methyl-D-aspartate (NMDA) receptor, p38, and ERK mitogen-activated protein kinase (MAPK) pathway. The blocking of the NMDA receptor by its antagonists MK-801 reduced PGC-1alpha mRNA expression in OGD neurons, while NMDA itself can directly induce the expression of PGC-1alpha in neuronal cells. At the same time, PD98059 (ERK MAPK inhibitor) and SB203580 (P38 MAPK inhibitor) also prevented the up-regulation of PGC-1alpha in OGD neurons and MK801 can inhibit the expression of P38 and ERK MAPK. These data suggested that the expression of PGC-1alpha was up-regulated in OGD mice cortical neurons, which protected the neurons against OGD injury. Moreover, this effect was correlated to the NMDA receptor and the ERK and P38 MAPK pathway. The protective effect of PGC-1alpha on OGD cortical neurons may be useful for stroke therapy.

Chronic ethanol exposure enhances the aggressiveness of breast cancer: the role of p38γ

PubMed Central

Xu, Mei; Wang, Siying; Ren, Zhenhua; Frank, Jacqueline A.; Yang, Xiuwei H.; Zhang, Zhuo; Ke, Zun-ji; Shi, Xianglin; Luo, Jia

2016-01-01

Both epidemiological and experimental studies suggest that ethanol may enhance aggressiveness of breast cancer. We have previously demonstrated that short term exposure to ethanol (12–48 hours) increased migration/invasion in breast cancer cells overexpressing ErbB2, but not in breast cancer cells with low expression of ErbB2, such as MCF7, BT20 and T47D breast cancer cells. In this study, we showed that chronic ethanol exposure transformed breast cancer cells that were not responsive to short term ethanol treatment to a more aggressive phenotype. Chronic ethanol exposure (10 days - 2 months) at 100 (22 mM) or 200 mg/dl (44 mM) caused the scattering of MCF7, BT20 and T47D cell colonies in a 3-dimension culture system. Chronic ethanol exposure also increased colony formation in an anchorage-independent condition and stimulated cell invasion/migration. Chronic ethanol exposure increased cancer stem-like cell (CSC) population by more than 20 folds. Breast cancer cells exposed to ethanol in vitro displayed a much higher growth rate and metastasis in mice. Ethanol selectively activated p38γ MAPK and RhoC but not p38α/β in a concentration-dependent manner. SP-MCF7 cells, a derivative of MCF7 cells which compose mainly CSC expressed high levels of phosphorylated p38γ MAPK. Knocking-down p38γ MAPK blocked ethanol-induced RhoC activation, cell scattering, invasion/migration and ethanol-increased CSC population. Furthermore, knocking-down p38γ MAPK mitigated ethanol-induced tumor growth and metastasis in mice. These results suggest that chronic ethanol exposure can enhance the aggressiveness of breast cancer by activating p38γ MAPK/RhoC pathway. PMID:26655092

Angiotensin II increases CTGF expression via MAPKs/TGF-{beta}1/TRAF6 pathway in atrial fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Jun; Liu, Xu, E-mail: xkliuxu@yahoo.cn; Wang, Quan-xing, E-mail: shmywqx@126.com

2012-10-01

The activation of transforming growth factor-{beta}1(TGF-{beta}1)/Smad signaling pathway and increased expression of connective tissue growth factor (CTGF) induced by angiotensin II (AngII) have been proposed as a mechanism for atrial fibrosis. However, whether TGF{beta}1/non-Smad signaling pathways involved in AngII-induced fibrogenetic factor expression remained unknown. Recently tumor necrosis factor receptor associated factor 6 (TRAF6)/TGF{beta}-associated kinase 1 (TAK1) has been shown to be crucial for the activation of TGF-{beta}1/non-Smad signaling pathways. In the present study, we explored the role of TGF-{beta}1/TRAF6 pathway in AngII-induced CTGF expression in cultured adult atrial fibroblasts. AngII (1 {mu}M) provoked the activation of P38 mitogen activated proteinmore » kinase (P38 MAPK), extracellular signal-regulated kinase 1/2(ERK1/2) and c-Jun NH(2)-terminal kinase (JNK). AngII (1 {mu}M) also promoted TGF{beta}1, TRAF6, CTGF expression and TAK1 phosphorylation, which were suppressed by angiotensin type I receptor antagonist (Losartan) as well as p38 MAPK inhibitor (SB202190), ERK1/2 inhibitor (PD98059) and JNK inhibitor (SP600125). Meanwhile, both TGF{beta}1 antibody and TRAF6 siRNA decreased the stimulatory effect of AngII on TRAF6, CTGF expression and TAK1 phosphorylation, which also attenuated AngII-induced atrial fibroblasts proliferation. In summary, the MAPKs/TGF{beta}1/TRAF6 pathway is an important signaling pathway in AngII-induced CTGF expression, and inhibition of TRAF6 may therefore represent a new target for reversing Ang II-induced atrial fibrosis. -- Highlights: Black-Right-Pointing-Pointer MAPKs/TGF{beta}1/TRAF6 participates in AngII-induced CTGF expression in atrial fibroblasts. Black-Right-Pointing-Pointer TGF{beta}1/TRAF6 participates in AngII-induced atrial fibroblasts proliferation. Black-Right-Pointing-Pointer TRAF6 may represent a new target for reversing Ang II-induced atrial fibrosis.« less

Effect of baicalin on GLUT4 expression and glucose uptake in myotubes of rats.

PubMed

Fang, Penghua; Yu, Mei; Min, Wen; Wan, Dan; Han, Shiyu; Shan, Yizhi; Wang, Rui; Shi, Mingyi; Zhang, Zhenwen; Bo, Ping

2018-03-01

Although baicalin could attenuate obesity-induced insulin resistance, the detailed mechanism of baicalin on glucose uptake has not been sufficiently explored as yet. The aim of this study was to survey if baicalin might facilitate glucose uptake and to explore its signal mechanisms in L6 myotubes. L6 myotubes were treated with 100, 200, 400 μM baicalin for 6 h, 12 h and 24 h in this study. Then 2-NBDG and insulin signal protein levels in myotubes of L6 cells were examined. We discovered that administration of baicalin enhanced GLUT4, PGC-1α, pP38MAPK, pAKT and pAS160 contents, as well as GLUT4 mRNA and PGC-1α mRNA levels in L6 myotubes. The beneficial metabolic changes elicited by baicalin were abrogated in myotubes of L6 by P38MAPK or AKT inhibitors. These results suggest that baicalin promoted glucose uptake in myotubes by differential regulation on P38MAPK and AKT activity. In conclusion, these data provide insight that baicalin is a powerful and promising agent for the treament of hyperglycemia via AKT/AS160/GLUT4 and P38MAPK/PGC1α/GLUT4 pathway. Copyright © 2018 Elsevier Inc. All rights reserved.

Cross-talk between Smad and p38 MAPK signalling in transforming growth factor {beta} signal transduction in human glioblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dziembowska, Magdalena; Danilkiewicz, Malgorzata; Wesolowska, Aleksandra

2007-03-23

Transforming growth factor-beta (TGF-{beta}) is a multifunctional cytokine involved in the regulation of cell proliferation, differentiation, and survival. Malignant tumour cells often do not respond to TGF-{beta} by growth inhibition, but retain responsiveness to cytokine in regulating extracellular matrix deposition, cell adhesion, and migration. We demonstrated that TGF-{beta}1 does not affect viability or proliferation of human glioblastoma T98G, but increases transcriptional responses exemplified by induction of MMP-9 expression. TGF-{beta} receptors were functional in T98G glioblastoma cells leading to SMAD3/SMAD4 nuclear translocation and activation of SMAD-dependent promoter. In parallel, a selective activation of p38 MAPK, and phosphorylation of its substrates: ATF2more » and c-Jun proteins were followed by a transient activation of AP-1 transcription factor. Surprisingly, an inhibition of p38 MAPK with a specific inhibitor, SB202190, abolished TGF-inducible activation of Smad-dependent promoter and decreased Smad2 phosphorylation. It suggests an unexpected interaction between Smad and p38 MAPK pathways in TGF-{beta}1-induced signalling.« less

Nox4 NADPH oxidase-derived reactive oxygen species, via endogenous carbon monoxide, promote survival of brain endothelial cells during TNF-α-induced apoptosis

PubMed Central

Basuroy, Shyamali; Tcheranova, Dilyara; Bhattacharya, Sujoy; Leffler, Charles W.

2011-01-01

We investigated the role of reactive oxygen species (ROS) in promoting cell survival during oxidative stress induced by the inflammatory mediator tumor necrosis factor-α (TNF-α) in cerebral microvascular endothelial cells (CMVEC) from newborn piglets. Nox4 is the major isoform of NADPH oxidase responsible for TNF-α-induced oxidative stress and apoptosis in CMVEC. We present novel data that Nox4 NADPH oxidase-derived ROS also initiate a cell survival mechanism by increasing production of a gaseous antioxidant mediator carbon monoxide (CO) by constitutive heme oxygenase-2 (HO-2). TNF-α rapidly enhanced endogenous CO production in a superoxide- and NADPH oxidase-dependent manner in CMVEC with innate, but not with small interfering RNA (siRNA)-downregulated Nox4 activity. CORM-A1, a CO-releasing compound, inhibited Nox4-mediated ROS production and enhanced cell survival in TNF-α-challenged CMVEC. The ROS-induced CO-mediated survival mechanism requires functional interactions between the protein kinase B/Akt and extracellular signal-related kinase (ERK)/p38 MAPK signaling pathways activated by TNF-α. In Akt siRNA-transfected CMVEC and in cells with pharmacologically inhibited Akt, Erk1/2, and p38 mitogen-activated protein kinase (MAPK) activities, CORM-A1 was no longer capable of blocking Nox4 activation and apoptosis caused by TNF-α. Overall, Nox4 NADPH oxidase-derived ROS initiate both death and survival pathways in TNF-α-challenged CMVEC. The ROS-dependent cell survival pathway is mediated by an endogenous antioxidant CO, which inhibits Nox4 activation via a mechanism that includes Akt, ERK1/2, and p38 MAPK signaling pathways. The ability of CO to inhibit TNF-α-induced ERK1/2 and p38 MAPK activities in an Akt-dependent manner appears to be the key element in ROS-dependent survival of endothelial cells during TNF-α-mediated brain inflammatory disease. PMID:21123734

Coal-induced interleukin-6 gene expression is mediated through ERKs and p38 MAPK pathways.

PubMed

Huang, X; Zhang, Q

2003-08-15

In the present study, we have tested the ability of coal dust to stimulate kinase phosphorylation of activator protein-1 (AP-1) signal transduction pathways and production of interleukin-6 (IL-6) in both mouse epidermal JB6 and human lung epithelial A549 cells. Seven coal samples from three coalmine regions of Pennsylvania (PA), West Virginia (WV), and Utah (UT) with high, medium, and low prevalence of coal workers' pneumoconiosis (CWP), respectively, were investigated. Results from the present study indicate that three PA coals stimulated the mitogen-activated protein kinase (MAPK) family of extracellular signal-regulated kinases (ERKs) and p38 MAPK, but not c-Jun-NH2-terminal kinases (JNKs) in human lung A549 cells. The effects of three UT coals on the kinase phosphorylation were less as compared to those of the PA coals. Coal dusts from three coalmine regions induced IL-6 in a dose-dependent manner in both JB6 and A549 cells. Interestingly, levels of IL-6 in both cells treated with coals from three coalmine regions correlated well with CWP prevalence from that region. To assess the role of AP-1 pathways in coal-mediated transcriptional activation of IL-6, various inhibitors were used in cells treated with one PA coal, which induced a maximal response. It was found that the increase in IL-6 protein and mRNA by the PA coal was completely eliminated by the pretreatment of both cell types with PD98059, a specific MEK1 inhibitor, and SB202190, a p38 kinase inhibitor. Our results indicate that coal dust can stimulate IL-6 release from mouse epidermal JB6 cells and human lung epithelial A549 cells, and the coal-induced IL-6 increase may involve ERKs and p38 MAPK pathways.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, Caiyan; Laboratory of Signal Transduction, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi; Clinical Medicine Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Hohhot, Inner Mongolia

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

Leptin regulates MMP-2, TIMP-1 and collagen synthesis via p38 MAPK in HL-1 murine cardiomyocytes.

PubMed

Schram, Kristin; De Girolamo, Sabrina; Madani, Siham; Munoz, Diana; Thong, Farah; Sweeney, Gary

2010-12-01

A clear association between obesity and heart failure exists and a significant role for leptin, the product of the obese gene, has been suggested. One aspect of myocardial remodeling which characterizes heart failure is a disruption in the balance of extracellular matrix synthesis and degradation. Here we investigated the effects of leptin on matrix metalloproteinase (MMP) activity, tissue inhibitor of metalloproteinase (TIMP) expression, as well as collagen synthesis in HL-1 cardiac muscle cells. Gelatin zymographic analysis of MMP activity in conditioned media showed that leptin enhanced MMP-2 activity in a dose- and time-dependent manner. Leptin is known to stimulate phosphorylation of p38 MAPK in cardiac cells and utilization of the p38 MAPK inhibitor, SB203580, demonstrated that this kinase also plays a role in regulating several extracellular matrix components, such that inhibition of p38 MAPK signaling prevented the leptin-induced increase in MMP-2 activation. We also observed that leptin enhanced collagen synthesis determined by both proline incorporation and picrosirius red staining of conditioned media. Pro-collagen type-I and pro-collagen type-III expression, measured by real-time PCR and Western blotting were also increased by leptin, effects which were again attenuated by SB203580. In summary, these results demonstrate the potential for leptin to play a role in mediating myocardial ECM remodeling and that the p38 MAPK pathway plays an important role in mediating these effects.

Involvement of p38 MAPK- and JNK-modulated expression of Bcl-2 and Bax in Naja nigricollis CMS-9-induced apoptosis of human leukemia K562 cells.

PubMed

Chen, Ying-Jung; Liu, Wen-Hsin; Kao, Pei-Hsiu; Wang, Jeh-Jeng; Chang, Long-Sen

2010-06-15

CMS-9, a phospholipase A(2) (PLA(2)) isolated from Naja nigricollis venom, induced apoptosis of human leukemia K562 cells, characterized by mitochondrial depolarization, modulation of Bcl-2 family members, cytochrome c release and activation of caspases 9 and 3. Moreover, an increase in intracellular Ca2+ concentration and the production of reactive oxygen species (ROS) was noted. Pretreatment with BAPTA-AM (Ca2+ chelator) and N-acetylcysteine (NAC, ROS scavenger) proved that Ca2+ was an upstream event in inducing ROS generation. Upon exposure to CMS-9, activation of p38 MAPK and JNK was observed in K562 cells. BAPTA-AM or NAC abrogated CMS-9-elicited p38 MAPK and JNK activation, and rescued viability of CMS-9-treated K562 cells. SB202190 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor) suppressed CMS-9-induced dissipation of mitochondrial membrane potential, Bcl-2 down-regulation, Bax up-regulation and increased mitochondrial translocation of Bax. Inactivation of PLA(2) activity reduced drastically the cytotoxicity of CMS-9, and a combination of lysophosphatidylcholine and stearic acid mimicked the cytotoxic effects of CMS-9. Taken together, our data suggest that CMS-9-induced apoptosis of K562 cells is catalytic activity-dependent and is mediated through mitochondria-mediated death pathway triggered by Ca2+/ROS-evoked p38 MAPK and JNK activation. 2010 Elsevier Ltd. All rights reserved.

Protective Effect of Tropisetron on Rodent Hepatic Injury after Trauma-Hemorrhagic Shock through P38 MAPK-Dependent Hemeoxygenase-1 Expression

PubMed Central

Hwang, Tsong-Long; Tsai, Yung-Fong

2012-01-01

Tropisetron can decrease inflammatory cell responses and alleviate organ damage caused by trauma-hemorrhage, but the mechanism of these effects remains unknown. The p38 mitogen-activated protein kinase/hemeoxygenase-1 (p38 MAPK/HO-1) pathway exerts anti-inflammatory effects on different tissues. The aim of this study was to investigate whether p38 MAPK/HO-1 plays any role in the tropisetron-mediated attenuation of hepatic injury after trauma-hemorrhage. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure maintained at approximately 35–40 mmHg for 90 min), followed by fluid resuscitation. During resuscitation, several treatment regimens were administered: four doses of tropisetron alone (0.1, 0.3, 1, 3 mg/kg body weight), or a single dose of tropisetron (1 mg/kg body weight) with and without a p38 MAPK inhibitor (SB-203580, 2 mg/kg body weight) or HO antagonist (chromium-mesoporphyrin, 2.5 mg/kg body weight). Various parameters were measured, and the animals were sacrificed at 24 h post-resuscitation. The results showed that trauma-hemorrhage increased the following parameters: plasma concentrations of aspartate (AST) and alanine aminotransferases (ALT), hepatic myeloperoxidase (MPO) activity, and levels of cytokine-induced neutrophil chemoattractant-1 and -3 (CINC-1 and CINC-3), intercellular adhesion molecule-1 (ICAM-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and macrophage inflammatory protein-1α (MIP-1α). These parameters were significantly improved in the tropisetron-treated rats subjected to trauma-hemorrhage. Tropisetron treatment also increased hepatic p38 MAPK and HO-1 expression compared with vehicle-treated trauma-hemorrhaged rats. Co-administration of SB-203580 or chromium-mesoporphyrin with tropisetron abolished the tropisetron-induced beneficial effects on the above parameters and hepatic injury. These results suggest that the protective effect of tropisetron administration on alleviation of hepatic injury after trauma-hemorrhage is likely mediated through p38 MAPK-dependent HO-1 expression. PMID:23285267

Protective effect of tropisetron on rodent hepatic injury after trauma-hemorrhagic shock through P38 MAPK-dependent hemeoxygenase-1 expression.

PubMed

Liu, Fu-Chao; Yu, Huang-Ping; Hwang, Tsong-Long; Tsai, Yung-Fong

2012-01-01

Tropisetron can decrease inflammatory cell responses and alleviate organ damage caused by trauma-hemorrhage, but the mechanism of these effects remains unknown. The p38 mitogen-activated protein kinase/hemeoxygenase-1 (p38 MAPK/HO-1) pathway exerts anti-inflammatory effects on different tissues. The aim of this study was to investigate whether p38 MAPK/HO-1 plays any role in the tropisetron-mediated attenuation of hepatic injury after trauma-hemorrhage. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure maintained at approximately 35-40 mmHg for 90 min), followed by fluid resuscitation. During resuscitation, several treatment regimens were administered: four doses of tropisetron alone (0.1, 0.3, 1, 3 mg/kg body weight), or a single dose of tropisetron (1 mg/kg body weight) with and without a p38 MAPK inhibitor (SB-203580, 2 mg/kg body weight) or HO antagonist (chromium-mesoporphyrin, 2.5 mg/kg body weight). Various parameters were measured, and the animals were sacrificed at 24 h post-resuscitation. The results showed that trauma-hemorrhage increased the following parameters: plasma concentrations of aspartate (AST) and alanine aminotransferases (ALT), hepatic myeloperoxidase (MPO) activity, and levels of cytokine-induced neutrophil chemoattractant-1 and -3 (CINC-1 and CINC-3), intercellular adhesion molecule-1 (ICAM-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and macrophage inflammatory protein-1α (MIP-1α). These parameters were significantly improved in the tropisetron-treated rats subjected to trauma-hemorrhage. Tropisetron treatment also increased hepatic p38 MAPK and HO-1 expression compared with vehicle-treated trauma-hemorrhaged rats. Co-administration of SB-203580 or chromium-mesoporphyrin with tropisetron abolished the tropisetron-induced beneficial effects on the above parameters and hepatic injury. These results suggest that the protective effect of tropisetron administration on alleviation of hepatic injury after trauma-hemorrhage is likely mediated through p38 MAPK-dependent HO-1 expression.

Mitogen activated protein kinase (MAPK) pathway regulates heme oxygenase-1 gene expression by hypoxia in vascular cells.

PubMed

Ryter, Stefan W; Xi, Sichuan; Hartsfield, Cynthia L; Choi, Augustine M K

2002-08-01

Hypoxia induces the stress protein heme oxygenase-1 (HO-1), which participates in cellular adaptation. The molecular pathways that regulate ho-1 gene expression under hypoxia may involve mitogen activated protein kinase (MAPK) signaling and reactive oxygen. Hypoxia (8 h) increased HO-1 mRNA in rat pulmonary aortic endothelial cells (PAEC), and also activated both extracellular signal-regulated kinase 1 (ERK1)/ERK2 and p38 MAPK pathways. The role of these kinases in hypoxia-induced ho-1 gene expression was examined using chemical inhibitors of these pathways. Surprisingly, SB203580, an inhibitor of p38 MAPK, and PD98059, an inhibitor of mitogen-activated protein kinase kinase (MEK1), strongly enhanced hypoxia-induced HO-1 mRNA expression in PAEC. UO126, a MEK1/2 inhibitor, enhanced HO-1 expression in PAEC under normoxia, but not hypoxia. Diphenylene iodonium, an inhibitor of NADPH oxidase, also induced the expression of HO-1 in PAEC under both normoxia and hypoxia. Similar results were observed in aortic vascular smooth muscle cells. Furthermore, hypoxia induced activator protein (AP-1) DNA-binding activity in PAEC. Pretreatment with SB203580 and PD98059 enhanced AP-1 binding activity under hypoxia in PAEC; UO126 stimulated AP-1 binding under normoxia, whereas diphenylene iodonium stimulated AP-1 binding under normoxia and hypoxia. These results suggest a relationship between MAPK and hypoxic regulation of ho-1 in vascular cells, involving AP-1.

Intracellular Networks of the PI3K/AKT and MAPK Pathways for Regulating Toxoplasma gondii-Induced IL-23 and IL-12 Production in Human THP-1 Cells

PubMed Central

Choi, In-Wook; Ismail, Hassan Ahmed Hassan Ahmed; Zhou, Wei; Cha, Guang-Ho; Zhou, Yu; Yuk, Jae-Min; Jo, Eun-Kyeong; Lee, Young-Ha

2015-01-01

Interleukin (IL)-23 and IL-12 are closely related in structure, and these cytokines regulate both innate and adaptive immunity. However, the precise signaling networks that regulate the production of each in Toxoplasma gondii-infected THP-1 monocytic cells, particularly the PI3K/AKT and MAPK signaling pathways, remain unknown. In the present study, T. gondii infection upregulated the expression of IL-23 and IL-12 in THP-1 cells, and both cytokines increased with parasite dose. IL-23 secretion was strongly inhibited by TLR2 monoclonal antibody (mAb) treatment in a dose-dependent manner and by TLR2 siRNA transfection, whereas IL-12 secretion was strongly inhibited by TLR4 mAb treatment dose-dependently and by TLR4 siRNA transfection. IL-23 production was dose-dependently inhibited by the PI3K inhibitors LY294002 and wortmannin, whereas IL-12 production increased dose-dependently. THP-1 cells exposed to live T. gondii tachyzoites underwent rapid p38 MAPK, ERK1/2 and JNK activation. IL-23 production was significantly upregulated by the p38 MAPK inhibitor SB203580 dose-dependently, whereas pretreatment with 10 μM SB203580 significantly downregulated IL-12 production. ERK1/2 inhibition by PD98059 was significantly downregulated IL-23 production but upregulated IL-12 production. JNK inhibition by SP600125 upregulated IL-23 production, but IL-12 production was significantly downregulated dose-dependently. T. gondii infection resulted in AKT activation, and AKT phosphorylation was inhibited dose-dependently after pretreatment with PI3K inhibitors. In T. gondii-infected THP-1 cells, ERK1/2 activation was regulated by PI3K; however, the phosphorylation of p38 MAPK and JNK was negatively modulated by the PI3K signaling pathway. Collectively, these results indicate that IL-23 production in T. gondii-infected THP-1 cells was regulated mainly by TLR2 and then by PI3K and ERK1/2; however, IL-12 production was mainly regulated by TLR4 and then by p38 MAPK and JNK. Our findings provide new insight concerning the intracellular networks of the PI3K/AKT and MAPK signaling cascades for regulating T. gondii-induced IL-23 and IL-12 secretion in human monocytic cells. PMID:26528819

MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simões, Maylla Ronacher, E-mail: yllars@hotmail.com; Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz; Aguado, Andrea

Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and didmore » not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by MAPK in lead exposure • Relationship between vascular ROS and COX-2 products in lead exposure.« less

Fragment-based drug discovery of potent and selective MKK3/6 inhibitors.

PubMed

Adams, Mark; Kobayashi, Toshitake; Lawson, J David; Saitoh, Morihisa; Shimokawa, Kenichiro; Bigi, Simone V; Hixon, Mark S; Smith, Christopher R; Tatamiya, Takayuki; Goto, Masayuki; Russo, Joseph; Grimshaw, Charles E; Swann, Steven

2016-02-01

The MAPK signaling cascade, comprised of several linear and intersecting pathways, propagates signaling into the nucleus resulting in cytokine and chemokine release. The Map Kinase Kinase isoforms 3 and 6 (MKK3 and MKK6) are responsible for the phosphorylation and activation of p38, and are hypothesized to play a key role in regulating this pathway without the redundancy seen in downstream effectors. Using FBDD, we have discovered efficient and selective inhibitors of MKK3 and MKK6 that can serve as tool molecules to help further understand the role of these kinases in MAPK signaling, and the potential impact of inhibiting kinases upstream of p38. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yanyan; Gao, Chao; Shi, Yanru

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.more » 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.« less

Hsa-let-7c controls the committed differentiation of IGF-1-treated mesenchymal stem cells derived from dental pulps by targeting IGF-1R via the MAPK pathways.

PubMed

Liu, Gen-Xia; Ma, Shu; Li, Yao; Yu, Yan; Zhou, Yi-Xiang; Lu, Ya-Die; Jin, Lin; Wang, Zi-Lu; Yu, Jin-Hua

2018-04-13

The putative tumor suppressor microRNA let-7c is extensively associated with the biological properties of cancer cells. However, the potential involvement of let-7c in the differentiation of mesenchymal stem cells has not been fully explored. In this study, we investigated the influence of hsa-let-7c (let-7c) on the proliferation and differentiation of human dental pulp-derived mesenchymal stem cells (DPMSCs) treated with insulin-like growth factor 1 (IGF-1) via flow cytometry, CCK-8 assays, alizarin red staining, real-time RT-PCR, and western blotting. In general, the proliferative capabilities and cell viability of DPMSCs were not significantly affected by the overexpression or deletion of let-7c. However, overexpression of let-7c significantly inhibited the expression of IGF-1 receptor (IGF-1R) and downregulated the osteo/odontogenic differentiation of DPMSCs, as indicated by decreased levels of several osteo/odontogenic markers (osteocalcin, osterix, runt-related transcription factor 2, dentin sialophosphoprotein, dentin sialoprotein, alkaline phosphatase, type 1 collagen, and dentin matrix protein 1) in IGF-1-treated DPMSCs. Inversely, deletion of let-7c resulted in increased IGF-1R levels and enhanced osteo/odontogenic differentiation. Furthermore, the ERK, JNK, and P38 MAPK pathways were significantly inhibited following the overexpression of let-7c in DPMSCs. Deletion of let-7c promoted the activation of the JNK and P38 MAPK pathways. Our cumulative findings indicate that Let-7c can inhibit the osteo/odontogenic differentiation of IGF-1-treated DPMSCs by targeting IGF-1R via the JNK/P38 MAPK signaling pathways.

The protective effect of Rhizoma Dioscoreae extract against alveolar bone loss in ovariectomized rats via regulating Wnt and p38 MAPK signaling.

PubMed

Zhang, Zhiguo; Xiang, Lihua; Bai, Dong; Wang, Wenlai; Li, Yan; Pan, Jinghua; Liu, Hong; Wang, Shaojun; Xiao, Gary Guishan; Ju, Dahong

2014-12-12

The aim of this study was to evaluate the osteoprotective effect of aqueous Rhizoma Dioscoreae extract (RDE) on the alveolar bone of rats with ovariectomy-induced bone loss. Female Wistar rats were subjected to either ovariectomy or a sham operation (SHAM). The ovariectomized (OVX) rats were treated with vehicle (OVX) or RDE by oral gavage or with 17β-estradiol (E2) subcutaneously. After treatments, the bone mineral density (BMD), the three-dimensional bone architecture of the alveolar bone and the plasma biomarkers of bone turnover were analyzed to assess bone metabolism, and the histomorphometry of the alveolar bone was observed. Microarrays were used to evaluate gene expression profiles in alveolar bone from RDE-treated and OVX rats. The differential expression of genes was further analyzed using Ingenuity Pathway Analysis (IPA). The key findings were verified using real-time quantitative RT-PCR (qRT-PCR). Our results showed that RDE inhibited alveolar bone loss in OVX rats. Compared to the OVX rats, the RDE-treated rats showed upregulated expression levels of 207 genes and downregulated expression levels of 176 genes in the alveolar bone. The IPA showed that several genes had the potential to code for proteins that were involved in the Wnt/β-catenin signaling pathway (Wnt7a, Fzd2, Tcf3, Spp1, Frzb, Sfrp2 and Sfrp4) and the p38 MAPK signaling pathway (Il1rn and Mapk14). These experiments revealed that RDE could inhibit ovariectomy-induced alveolar bone loss in rats. The mechanism of this anti-osteopenic effect in alveolar bone may be involved in the reduced abnormal bone remodeling, which is associated with the modulation of the Wnt/β-catenin and the p38 MAPK signaling pathways via gene regulation.

Signaling pathways activation by primary endodontic infectious contents and production of inflammatory mediators.

PubMed

Martinho, Frederico C; Leite, Fabio R M; Chiesa, Wanderson M M; Nascimento, Gustavo G; Feres, Magda; Gomes, Brenda P F A

2014-04-01

This study investigated the bacterial community involved in primary endodontic diseases, evaluated its ability to activate the macrophage Toll-like receptor 4 receptor through p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways, and determined the levels of endotoxins and interleukins (interleukin [IL]-6 and -10) produced by endodontic content-stimulated macrophages. Samples were taken from 21 root canals by using sterile/apyrogenic paper points. Raw 264.7 macrophages were stimulated with root canal contents. Checkerboard DNA-DNA hybridization was used for bacterial analysis and the limulus amebocyte lysate assay for endotoxin measurement; p38 MAPK and NF-κB activation was determined by Western blot analysis. IL-6 and IL-10 were measured using the enzyme-linked immunosorbent assay. Bacteria and endotoxins were detected in 100% of the samples (21/21). The most frequently observed species were Parvimonas micra (16/21, 76%), Fusobacterium nucleatum ssp. nucleatum (15/21, 71%), and Porphyromonas endodontalis (14/21, 66%). Correlations were found between endotoxins and IL-6 and IL-10 (P < .05); p38 phosphorylation had a peak at 60 minutes, and NF-κB was quickly activated after 10 minutes of stimulation. It was concluded that the complex bacterial community was shown to be a potent activator of TLR-4 determined by the p38 MAPK and NF-κB signaling pathways, culminating in a high antigenicity against macrophages through the levels of IL-6 and IL-10, all significantly affected by endotoxin levels. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Tumorigenicity of MCF-7 human breast cancer cells lacking the p38α mitogen-activated protein kinase.

PubMed

Mendoza, Rhone A; Moody, Emily E; Enriquez, Marlene I; Mejia, Sylvia M; Thordarson, Gudmundur

2011-01-01

We have generated cell lines with significantly reduced expression of the p38 mitogen-activated protein kinase (p38 MAPK), Min-p38 MAPK cells, and used these cells to investigate p38 MAPK's role in tumorigenesis of breast cancer cells. MCF-7 cells were stably transfected with a plasmid producing small interfering RNA that inhibited the expression of p38 MAPK. Control cells were stably transfected with the same plasmid producing non-interfering RNA. The reduction in the p38 MAPK activity caused a significant increase in the expressions of estrogen receptor-α (ERα) and the progesterone receptor, but eliminated the expression of ERβ. Min-p38 MAPK cells showed an enhanced overall growth response to 17β-estradiol (E₂), whereas GH plus epidermal growth factor were largely ineffective growth stimulators in these cells compared to controls. Although the long-term net growth rate of the Min-p38 MAPK cells was increased in response to E₂, their proliferation rate was lower compared to controls in short-term cultures. However, the Min-p38 MAPK cells did show a significant decreased rate of apoptosis after E₂ treatment and a reduction in the basal phosphorylation of p53 tumor suppressor protein compared to controls. When the Min-p38 MAPK cells were xenografted into E₂-treated athymic nude mice, their tumorigenicity was enhanced compared to control cells. Increased tumorigenicity of Min-p38 MAPK cells was caused mainly by a decrease in the apoptosis rate indicating that the lack of the p38 MAPK caused an imbalance to increase the ERα:ERβ ratio and a reduction in the activity of the p53 tumor suppressor protein.

Plumbagin induces cell cycle arrest and autophagy and suppresses epithelial to mesenchymal transition involving PI3K/Akt/mTOR-mediated pathway in human pancreatic cancer cells

PubMed Central

Wang, Feng; Wang, Qi; Zhou, Zhi-Wei; Yu, Song-Ning; Pan, Shu-Ting; He, Zhi-Xu; Zhang, Xueji; Wang, Dong; Yang, Yin-Xue; Yang, Tianxing; Sun, Tao; Li, Min; Qiu, Jia-Xuan; Zhou, Shu-Feng

2015-01-01

Plumbagin (PLB), an active naphthoquinone compound, has shown potent anticancer effects in preclinical studies; however, the effect and underlying mechanism of PLB for the treatment of pancreatic cancer is unclear. This study aimed to examine the pancreatic cancer cell killing effect of PLB and investigate the underlying mechanism in human pancreatic cancer PANC-1 and BxPC-3 cells. The results showed that PLB exhibited potent inducing effects on cell cycle arrest in PANC-1 and BxPC-3 cells via the modulation of cell cycle regulators including CDK1/CDC2, cyclin B1, cyclin D1, p21 Waf1/Cip1, p27 Kip1, and p53. PLB treatment concentration- and time-dependently increased the percentage of autophagic cells and significantly increased the expression level of phosphatase and tensin homolog, beclin 1, and the ratio of LC3-II over LC3-I in both PANC-1 and BxPC-3 cells. PLB induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin and p38 mitogen-activated protein kinase (p38 MAPK) pathways and activation of 5′-AMP-dependent kinase as indicated by their altered phosphorylation, contributing to the proautophagic activities of PLB in both cell lines. Furthermore, SB202190, a selective inhibitor of p38 MAPK, and wortmannin, a potent, irreversible, and selective PI3K inhibitor, remarkably enhanced PLB-induced autophagy in PANC-1 and BxPC-3 cells, indicating the roles of PI3K and p38 MAPK mediated signaling pathways in PLB-induced autophagic cell death in both cell lines. In addition, PLB significantly inhibited epithelial to mesenchymal transition phenotype in both cell lines with an increase in the expression level of E-cadherin and a decrease in N-cadherin. Moreover, PLB treatment significantly suppressed the expression of Sirt1 in both cell lines. These findings show that PLB promotes cell cycle arrest and autophagy but inhibits epithelial to mesenchymal transition phenotype in pancreatic cancer cells with the involvement of PI3K/protein kinase B/mammalian target of rapamycin and p38 MAPK mediated pathways. PMID:25632222

The FGL2/fibroleukin prothrombinase is involved in alveolar macrophage activation in COPD through the MAPK pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yanling; Xu, Sanpeng; Xiao, Fei

2010-05-28

Fibrinogen-like protein 2 (FGL2)/fibroleukin has been reported to play a vital role in the pathogenesis of some critical inflammatory diseases by possessing immunomodulatory activity through the mediation of 'immune coagulation' and the regulation of maturation and proliferation of immune cells. We observed upregulated FGL2 expression in alveolar macrophages from peripheral lungs of chronic obstructive pulmonary disease (COPD) patients and found a correlation between FGL2 expression and increased macrophage activation markers (CD11b and CD14). The role of FGL2 in the activation of macrophages was confirmed by the detection of significantly decreased macrophage activation marker (CD11b, CD11c, and CD71) expression as wellmore » as the inhibition of cell migration and inflammatory cytokine (IL-8 and MMP-9) production in an LPS-induced FGL2 knockdown human monocytic leukemia cell line (THP-1). Increased FGL2 expression co-localized with upregulated phosphorylated p38 mitogen-activated protein kinase (p38-MAPK) in the lung tissues from COPD patients. Moreover, FGL2 knockdown in THP-1 cells significantly downregulated LPS-induced phosphorylation of p38-MAPK while upregulating phosphorylation of c-Jun N-terminal kinase (JNK). Thus, we demonstrate that FGL2 plays an important role in macrophage activation in the lungs of COPD patients through MAPK pathway modulation.« less

Tumor p38MAPK signaling enhances breast carcinoma vascularization and growth by promoting expression and deposition of pro-tumorigenic factors.

PubMed

Limoge, Michelle; Safina, Alfiya; Truskinovsky, Alexander M; Aljahdali, Ieman; Zonneville, Justin; Gruevski, Aleksandar; Arteaga, Carlos L; Bakin, Andrei V

2017-09-22

The breast carcinoma microenvironment strikingly influences cancer progression and response to therapy. Various cell types in the carcinoma microenvironment show significant activity of p38 mitogen-activated protein kinase (MAPK), although the role of p38MAPK in breast cancer progression is still poorly understood. The present study examined the contribution of tumor p38MAPK to breast carcinoma microenvironment and metastatic capacity. Inactivation of p38MAPK signaling in metastatic breast carcinoma cells was achieved by forced expression of the kinase-inactive mutant of p38/MAPK14 (a dominant-negative p38, dn-p38). Disruption of tumor p38MAPK signaling reduced growth and metastases of breast carcinoma xenografts. Importantly, dn-p38 markedly decreased tumor blood-vessel density and lumen sizes. Mechanistic studies revealed that p38 controls expression of pro-angiogenic extracellular factors such as matrix protein Fibronectin and cytokines VEGFA, IL8, and HBEGF. Tumor-associated fibroblasts enhanced tumor growth and vasculature as well as increased expression of the pro-angiogenic factors. These effects were blunted by dn-p38. Metadata analysis showed elevated expression of p38 target genes in breast cancers and this was an unfavorable marker of disease recurrence and poor-outcome. Thus, our study demonstrates that tumor p38MAPK signaling promotes breast carcinoma growth, invasive and metastatic capacities. Importantly, p38 enhances carcinoma vascularization by facilitating expression and deposition of pro-angiogenic factors. These results argue that p38MAPK is a valuable target for anticancer therapy affecting tumor vasculature. Anti-p38 drugs may provide new therapeutic strategies against breast cancer, including metastatic disease.

Tumor p38MAPK signaling enhances breast carcinoma vascularization and growth by promoting expression and deposition of pro-tumorigenic factors

PubMed Central

Limoge, Michelle; Safina, Alfiya; Truskinovsky, Alexander M.; Aljahdali, Ieman; Zonneville, Justin; Gruevski, Aleksandar; Arteaga, Carlos L.; Bakin, Andrei V.

2017-01-01

The breast carcinoma microenvironment strikingly influences cancer progression and response to therapy. Various cell types in the carcinoma microenvironment show significant activity of p38 mitogen-activated protein kinase (MAPK), although the role of p38MAPK in breast cancer progression is still poorly understood. The present study examined the contribution of tumor p38MAPK to breast carcinoma microenvironment and metastatic capacity. Inactivation of p38MAPK signaling in metastatic breast carcinoma cells was achieved by forced expression of the kinase-inactive mutant of p38/MAPK14 (a dominant-negative p38, dn-p38). Disruption of tumor p38MAPK signaling reduced growth and metastases of breast carcinoma xenografts. Importantly, dn-p38 markedly decreased tumor blood-vessel density and lumen sizes. Mechanistic studies revealed that p38 controls expression of pro-angiogenic extracellular factors such as matrix protein Fibronectin and cytokines VEGFA, IL8, and HBEGF. Tumor-associated fibroblasts enhanced tumor growth and vasculature as well as increased expression of the pro-angiogenic factors. These effects were blunted by dn-p38. Metadata analysis showed elevated expression of p38 target genes in breast cancers and this was an unfavorable marker of disease recurrence and poor-outcome. Thus, our study demonstrates that tumor p38MAPK signaling promotes breast carcinoma growth, invasive and metastatic capacities. Importantly, p38 enhances carcinoma vascularization by facilitating expression and deposition of pro-angiogenic factors. These results argue that p38MAPK is a valuable target for anticancer therapy affecting tumor vasculature. Anti-p38 drugs may provide new therapeutic strategies against breast cancer, including metastatic disease. PMID:28977919

Thrombin-induced glucose transport via Src–p38 MAPK pathway in vascular smooth muscle cells

PubMed Central

Kanda, Yasunari; Watanabe, Yasuhiro

2005-01-01

Thrombin is a mitogen for vascular smooth muscle cells (VSMC) and has been implicated in the development in atherosclerosis. However, little is known about the role of thrombin in glucose transport in VSMC. In this study, we examined the effect of thrombin on glucose uptake in rat A10 VSMC. We found that thrombin induced glucose uptake in a dose-dependent manner while hirudin, a potent thrombin inhibitor, prevented glucose uptake in the cells. PP2, a selective inhibitor of Src, prevented the thrombin-induced glucose uptake, but did not affect insulin-induced uptake. We also examined whether mitogen-activated protein kinase (MAPK) inhibitors influenced thrombin-induced glucose uptake. The p38 MAPK inhibitor (SB203580) inhibited thrombin-induced glucose uptake, but the MEK inhibitor (PD98059) did not. In contrast to thrombin, SB203580 did not affect insulin-induced glucose uptake. Furthermore, thrombin failed to translocate the insulin-sensitive glucose transporter GLUT4. These findings suggest that thrombin stimulates glucose transport via Src and subsequent p38 MAPK activation in VSMC. PMID:15951827

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

PubMed

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

2014-08-25

A series of functionalized biaryl-4-carbonitriles was synthesized in three steps and evaluated for PTP-1B inhibitory activity. Among the synthesized compounds, four biaryls 6a-d showed inhibition (IC50 58-75 μM) against in vitro PTP-1B assay possibly due to interaction with amino acid residues Lys120, Tyr46 through hydrogen bonding and aromatic-aromatic interactions, respectively. Two biaryl-4-carbonitriles 6b and 6c showed improved glucose tolerance, fasting as well as postprandial blood glucose, serum total triglycerides, and increased high-density lipoprotein-cholesterol in SLM, STZ, STZ-S and C57BL/KsJ-db/db animal models. The bioanalysis of 4'-bromo-2,3-dimethyl-5-(piperidin-1-yl)biphenyl-4-carbonitrile (6b) revealed that like insulin, it increased 2-deoxyglucose uptake in skeletal muscle cells (L6 and C2C12 myotubes). The compound 6b significantly up-regulated the genes related to the insulin signaling pathways like AMPK, MAPK including glucose transporter-4 (GLUT-4) gene in muscle tissue of C57BL/KsJ-db/db mice. Furthermore, it was observed that the compound 6b up-regulated PPARα, UCP2 and HNF4α, which are key regulator of glucose, lipid, and fatty acid metabolism. Western blot analysis of the compound 6b showed that it significantly increased the phosphorylation of AMPK and p38 MAPK and ameliorated glucose uptake in C57BL/KsJ-db/db mice through the AMPK-p38 MAPK pathway. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Tanshinone IIA inhibits AGEs-induced proliferation and migration of cultured vascular smooth muscle cells by suppressing ERK1/2 MAPK signaling

PubMed Central

Lu, Ming; Luo, Ying; Hu, Pengfei; Dou, Liping; Huang, Shuwei

2018-01-01

Objective(s): Vascular smooth muscle cells (VSMCs) play a key role in the pathogenesis of diabetic vascular disease. Our current study sought to explore the effects of tanshinone IIA on the proliferation and migration of VSMCs induced by advanced glycation end products (AGEs). Materials and Methods: In this study, we examined the effects of tanshinone IIA by cell proliferation assay and cell migration assay. And we explored the underlying mechanism by Western blotting. Results: AGEs significantly induced the proliferation and migration of VSMCs, but treatment with tanshinone IIA attenuated these effects. AGEs could increase the activity of the ERK1/2 and p38 pathways but not the JNK pathway. Treatment with tanshinone IIA inhibited the AGEs-induced activation of the ERK1/2 pathway but not the p38 pathway. Conclusion: Tanshinone IIA inhibits AGEs-induced proliferation and migration of VSMCs by suppressing the ERK1/2 MAPK signaling pathway. PMID:29372041

Caffeine Inhibits the Activation of Hepatic Stellate Cells Induced by Acetaldehyde via Adenosine A2A Receptor Mediated by the cAMP/PKA/SRC/ERK1/2/P38 MAPK Signal Pathway

PubMed Central

Yang, Wanzhi; Wang, Qi; Zhao, Han; Yang, Feng; Lv, Xiongwen; Li, Jun

2014-01-01

Hepatic stellate cell (HSC) activation is an essential event during alcoholic liver fibrosis. Evidence suggests that adenosine aggravates liver fibrosis via the adenosine A2A receptor (A2AR). Caffeine, which is being widely consumed during daily life, inhibits the action of adenosine. In this study, we attempted to validate the hypothesis that caffeine influences acetaldehyde-induced HSC activation by acting on A2AR. Acetaldehyde at 50, 100, 200, and 400 μM significantly increased HSC-T6 cells proliferation, and cell proliferation reached a maximum at 48 h after exposure to 200 μM acetaldehyde. Caffeine and the A2AR antagonist ZM241385 decreased the cell viability and inhibited the expression of procollagen type I and type III in acetaldehyde-induced HSC-T6 cells. In addition, the inhibitory effect of caffeine on the expression of procollagen type I was regulated by A2AR-mediated signal pathway involving cAMP, PKA, SRC, and ERK1/2. Interestingly, caffeine’s inhibitory effect on the expression of procollagen type III may depend upon the A2AR-mediated P38 MAPK-dependent pathway. Conclusions: Caffeine significantly inhibited acetaldehyde-induced HSC-T6 cells activation by distinct A2AR mediated signal pathway via inhibition of cAMP-PKA-SRC-ERK1/2 for procollagen type I and via P38 MAPK for procollagen type III. PMID:24682220

p75 Neurotrophin Receptor Signaling Activates Sterol Regulatory Element-binding Protein-2 in Hepatocyte Cells via p38 Mitogen-activated Protein Kinase and Caspase-3.

PubMed

Pham, Dan Duc; Do, Hai Thi; Bruelle, Céline; Kukkonen, Jyrki P; Eriksson, Ove; Mogollón, Isabel; Korhonen, Laura T; Arumäe, Urmas; Lindholm, Dan

2016-05-13

Nerve growth factor (NGF) influences the survival and differentiation of a specific population of neurons during development, but its role in non-neuronal cells has been less studied. We observed here that NGF and its pro-form, pro-NGF, are elevated in fatty livers from leptin-deficient mice compared with controls, concomitant with an increase in low density lipoprotein receptors (LDLRs). Stimulation of mouse primary hepatocytes with NGF or pro-NGF increased LDLR expression through the p75 neurotrophin receptor (p75NTR). Studies using Huh7 human hepatocyte cells showed that the neurotrophins activate the sterol regulatory element-binding protein-2 (SREBP2) that regulates genes involved in lipid metabolism. The mechanisms for this were related to stimulation of p38 mitogen-activated protein kinase (p38 MAPK) and activation of caspase-3 and SREBP2 cleavage following NGF and pro-NGF stimulations. Cell fractionation experiments showed that caspase-3 activity was increased particularly in the membrane fraction that harbors SREBP2 and caspase-2. Experiments showed further that caspase-2 interacts with pro-caspase-3 and that p38 MAPK reduced this interaction and caused caspase-3 activation. Because of the increased caspase-3 activity, the cells did not undergo cell death following p75NTR stimulation, possibly due to concomitant activation of nuclear factor-κB (NF-κB) pathway by the neurotrophins. These results identify a novel signaling pathway triggered by ligand-activated p75NTR that via p38 MAPK and caspase-3 mediate the activation of SREBP2. This pathway may regulate LDLRs and lipid uptake particularly after injury or during tissue inflammation accompanied by an increased production of growth factors, including NGF and pro-NGF. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Meta-Analysis of Global Transcriptomics Suggests that Conserved Genetic Pathways are Responsible for Quercetin and Tannic Acid Mediated Longevity in C. elegans

PubMed Central

Pietsch, Kerstin; Saul, Nadine; Swain, Suresh C.; Menzel, Ralph; Steinberg, Christian E. W.; Stürzenbaum, Stephen R.

2012-01-01

Recent research has highlighted that the polyphenols Quercetin and Tannic acid are capable of extending the lifespan of Caenorhabditis elegans. To gain a deep understanding of the underlying molecular genetics, we analyzed the global transcriptional patterns of nematodes exposed to three concentrations of Quercetin or Tannic acid, respectively. By means of an intricate meta-analysis it was possible to compare the transcriptomes of polyphenol exposure to recently published datasets derived from (i) longevity mutants or (ii) infection. This detailed comparative in silico analysis facilitated the identification of compound specific and overlapping transcriptional profiles and allowed the prediction of putative mechanistic models of Quercetin and Tannic acid mediated longevity. Lifespan extension due to Quercetin was predominantly driven by the metabolome, TGF-beta signaling, Insulin-like signaling, and the p38 MAPK pathway and Tannic acid’s impact involved, in part, the amino acid metabolism and was modulated by the TGF-beta and the p38 MAPK pathways. DAF-12, which integrates TGF-beta and Insulin-like downstream signaling, and genetic players of the p38 MAPK pathway therefore seem to be crucial regulators for both polyphenols. Taken together, this study underlines how meta-analyses can provide an insight of molecular events that go beyond the traditional categorization into gene ontology-terms and Kyoto encyclopedia of genes and genomes-pathways. It also supports the call to expand the generation of comparative and integrative databases, an effort that is currently still in its infancy. PMID:22493606

Tunicamycin promotes apoptosis in leukemia cells through ROS generation and downregulation of survivin expression.

PubMed

Lim, Eun Jin; Heo, Jeonghoon; Kim, Young-Ho

2015-08-01

Tunicamycin (TN), one of the endoplasmic reticulum stress inducers, has been reported to inhibit tumor cell growth and exhibit anticarcinogenic activity. However, the mechanism by which TN initiates apoptosis remains poorly understood. In the present study, we investigated the effect of TN on the apoptotic pathway in U937 cells. We show that TN induces apoptosis in association with caspase-3 activation, generation of reactive oxygen species (ROS), and downregulation of survivin expression. P38 MAPK (mitogen-activated protein kinase) and the generation of ROS signaling pathway play crucial roles in TN-induced apoptosis in U937 cells. We hypothesized that TN-induced activation of p38 MAPK signaling pathway is responsible for cell death. To test this hypothesis, we selectively inhibited MAPK during treatment with TN. Our data demonstrated that inhibitor of p38 (SB), but not ERK (PD) or JNK (SP), partially maintained apoptosis during treatment with TN. Pre-treatment with NAC and GSH markedly prevented cell death, suggesting a role for ROS in this process. Ectopic expression of survivin in U937 cells attenuated TN-induced apoptosis by suppression of caspase-3 cleavage, mitochondrial membrane potential, and cytochrome c release in U937 cells. Taken together, our results show that TN modulates multiple components of the apoptotic response of human leukemia cells and raise the possibility of a novel therapeutic strategy for hematological malignancies.

The PDZ-Binding Motif of Severe Acute Respiratory Syndrome Coronavirus Envelope Protein Is a Determinant of Viral Pathogenesis

PubMed Central

Jimenez-Guardeño, Jose M.; Nieto-Torres, Jose L.; DeDiego, Marta L.; Regla-Nava, Jose A.; Fernandez-Delgado, Raul; Castaño-Rodriguez, Carlos; Enjuanes, Luis

2014-01-01

A recombinant severe acute respiratory syndrome coronavirus (SARS-CoV) lacking the envelope (E) protein is attenuated in vivo. Here we report that E protein PDZ-binding motif (PBM), a domain involved in protein-protein interactions, is a major determinant of virulence. Elimination of SARS-CoV E protein PBM by using reverse genetics caused a reduction in the deleterious exacerbation of the immune response triggered during infection with the parental virus and virus attenuation. Cellular protein syntenin was identified to bind the E protein PBM during SARS-CoV infection by using three complementary strategies, yeast two-hybrid, reciprocal coimmunoprecipitation and confocal microscopy assays. Syntenin redistributed from the nucleus to the cell cytoplasm during infection with viruses containing the E protein PBM, activating p38 MAPK and leading to the overexpression of inflammatory cytokines. Silencing of syntenin using siRNAs led to a decrease in p38 MAPK activation in SARS-CoV infected cells, further reinforcing their functional relationship. Active p38 MAPK was reduced in lungs of mice infected with SARS-CoVs lacking E protein PBM as compared with the parental virus, leading to a decreased expression of inflammatory cytokines and to virus attenuation. Interestingly, administration of a p38 MAPK inhibitor led to an increase in mice survival after infection with SARS-CoV, confirming the relevance of this pathway in SARS-CoV virulence. Therefore, the E protein PBM is a virulence domain that activates immunopathology most likely by using syntenin as a mediator of p38 MAPK induced inflammation. PMID:25122212

Opposite Roles for p38MAPK-Driven Responses and Reactive Oxygen Species in the Persistence and Resolution of Radiation-Induced Genomic Instability

PubMed Central

Werner, Erica; Wang, Huichen; Doetsch, Paul W.

2014-01-01

We report the functional and temporal relationship between cellular phenotypes such as oxidative stress, p38MAPK-dependent responses and genomic instability persisting in the progeny of cells exposed to sparsely ionizing low-Linear Energy Transfer (LET) radiation such as X-rays or high-charge and high-energy (HZE) particle high-LET radiation such as 56Fe ions. We found that exposure to low and high-LET radiation increased reactive oxygen species (ROS) levels as a threshold-like response induced independently of radiation quality and dose. This response was sustained for two weeks, which is the period of time when genomic instability is evidenced by increased micronucleus formation frequency and DNA damage associated foci. Indicators for another persisting response sharing phenotypes with stress-induced senescence, including beta galactosidase induction, increased nuclear size, p38MAPK activation and IL-8 production, were induced in the absence of cell proliferation arrest during the first, but not the second week following exposure to high-LET radiation. This response was driven by a p38MAPK-dependent mechanism and was affected by radiation quality and dose. This stress response and elevation of ROS affected genomic instability by distinct pathways. Through interference with p38MAPK activity, we show that radiation-induced stress phenotypes promote genomic instability. In contrast, exposure to physiologically relevant doses of hydrogen peroxide or increasing endogenous ROS levels with a catalase inhibitor reduced the level of genomic instability. Our results implicate persistently elevated ROS following exposure to radiation as a factor contributing to genome stabilization. PMID:25271419

SB203580 enhances the RV-induced loss of mitochondrial membrane potential and apoptosis in A549 cells

NASA Astrophysics Data System (ADS)

Li, Hai-yang; Zhuang, Cai-ping; Wang, Xiao-ping; Chen, Tong-sheng

2012-03-01

Resveratrol (RV), a naturally occurring phytoalexin, is known to possess a wide spectrum of chemopreventive and chemotherapeutic effects in various stages of human tumors. p38, a member of the mitogen-activated protein kinase (MAPK) superfamily, is always activated by some extracellular stimulus to regulate many cellular signal transduction pathways, such as apoptosis, proliferation, and inflammation and so on. In this report, we assessed the effect of SB203580, a specific inhibitor of p38 MAPK signaling pathway, on the RV-induced apoptosis in human lung adenocarcinoma (A549) cells. CCK-8 assay showed that pretreatment with SB203580 significantly enhanced the cytotoxicity of RV, which was further verified by analyzing the phosphatidylserine externalization using flow cytometry. In order to further confirm whether SB203580 accelerated apoptosis via the intrinsic apoptosis pathway, we analyzed the dysfunction of mitochondrial membrane potential (Δψm) of cells stained with rhodamine 123 by using flow cytometry after treatment with RV in the absence and presence of SB203580. Our data for the first time reported that p38 inhibitor SB203580 enhanced the RV-induced apoptosis via a mitochondrial pathway.

A prenylated flavonoid, 10-oxomornigrol F, exhibits anti-inflammatory effects by activating the Nrf2/heme oxygenase-1 pathway in macrophage cells.

PubMed

Tran, Phi-Long; Tran, Phuong Thao; Tran, Huynh Nguyen Khanh; Lee, Suhyun; Kim, Okwha; Min, Buyng-Sun; Lee, Jeong-Hyung

2018-02-01

Prenylated flavonoids are a unique class of naturally occurring flavonoids that have various pharmacological activities. In the present study, we investigated the anti-inflammatory effect in murine macrophages of a prenylated flavonoid, 10-oxomornigrol F (OMF), which was isolated from the twigs of Morus alba (Moraceae). OMF inhibited the lipopolysaccharide (LPS)-induced production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 in RAW264.7 cells, as well as in mouse bone marrow-derived macrophages (BMMs). OMF also rescued LPS-induced septic mortality in ICR mice. LPS-induced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α and IL-6 was also significantly suppressed by OMF treatment in RAW264.7 cells. Treatment of RAW264.7 cells with OMF induced heme oxygenase (HO)-1 mRNA and protein expression and increased the nuclear translocation of the nuclear factor-E2-related factor 2 (Nrf2) as well as the expression of Nrf2 target genes, such as NAD(P)H:quinone oxidoreductase 1 (NQO1). Treatment of RAW264.7 cells with OMF increased the intracellular level of reactive oxygen species (ROS) and the phosphorylation levels of p38 mitogen-activated protein kinase (MAPK); co-treatment with the antioxidant N-acetyl-cysteine (NAC) blocked this OMF-induced p38 MAPK phosphorylation. Moreover, NAC, or SB203580 (a p38 MAPK inhibitor), blocked the OMF-induced nuclear translocation of Nrf2 and HO-1 expression, suggesting that OMF induces HO-1 expression by activating Nrf2 through the p38 MAPK pathway. Consistent with the notion that the Nrf2/HO-1 pathway has anti-inflammatory properties, inhibiting HO-1 significantly abrogated the anti-inflammatory effects of OMF in LPS-stimulated RAW264.7 cells. Taken together, these findings suggest that OMF exerts its anti-inflammatory effect by activating the Nrf2/HO-1 pathway, and may be a potential Nrf2 activator to prevent or treat inflammatory diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of the anti-inflammatory actions of various functional food materials including glucosamine on synovial cells.

PubMed

Yamagishi, Yoshie; Someya, Akimasa; Imai, Kensuke; Nagao, Junji; Nagaoka, Isao

2017-08-01

The anti-inflammatory actions of glucosamine (GlcN) on arthritic disorders involve the suppression of inflammatory mediator production from synovial cells. GlcN has also been reported to inhibit the activation of the p38 mitogen-activated protein kinase (MAPK) pathway. The present study aimed to determine the cooperative and anti‑inflammatory actions of functional food materials and evaluated the production of interleukin (IL)‑8 and phosphorylation of p38 MAPK in IL-1β-activated synovial cells, incubated with the combination of GlcN and various functional food materials containing L‑methionine (Met), undenatured type II collagen (UC‑II), chondroitin sulfate (CS), methylsulfonylmethane (MSM) and agaro-oligosaccharide (AO). The results indicated that Met, UC‑II, CS, MSM and AO slightly or moderately suppressed the IL-1β-stimulated IL‑8 production by human synovial MH7A cells. The same compounds further decreased the IL‑8 level lowered by GlcN. Similarly, they slightly suppressed the phosphorylation level of p38 MAPK and further reduced the phosphorylation level lowered by GlcN. These observations suggest a possibility that these functional food materials exert an anti‑inflammatory action (inhibition of IL‑8 production) in combination with GlcN by cooperatively suppressing the p38 MAPK signaling (phosphorylation).

Tumorigenicity of MCF-7 human breast cancer cells lacking the p38α mitogen-activated protein kinase

PubMed Central

Mendoza, Rhone A; Moody, Emily E; Enriquez, Marlene I; Mejia, Sylvia M; Thordarson, Gudmundur

2011-01-01

We have generated cell lines with significantly reduced expression of the p38 mitogen-activated protein kinase (p38 MAPK), Min-p38 MAPK cells, and used these cells to investigate its role in tumorigenesis of breast cancer cells. MCF-7 cells were stably transfected with a plasmid producing small interfering RNA that inhibited the expression of p38 MAPK. Control cells were stably transfected with the same plasmid producing non-interfering RNA. The reduction in the p38 MAPK activity caused a significant increase in the expressions of the estrogen receptor-α (ERα) and the progesterone receptor, but eliminated the expression of the ERβ. Min-p38 MAPK cells showed an enhanced overall growth response to 17β-estradiol (E2), whereas growth hormone plus epidermal growth factor were largely ineffective growth stimulators in these cells compared to controls. Although the long-term net growth rate of the Min-p38 MAPK cells was increased in response to E2, their proliferation rate was not different from controls in short-term cultures. However, the Min-p38 MAPK cells did show a significant decreased rate of apoptosis after E2 treatment and a reduction in the basal phosphorylation of p53 tumor suppressor protein compared to controls. When the Min-p38 MAPK cells were xenografted into E2-treated athymic nude mice, their tumorigenicity was enhanced compared to control cells. Conclusions: increased tumorigenicity of Min-p38 MAPK cells was caused mainly by a decrease in apoptosis rate indicating that the lack of the p38 MAPK caused an imbalance to increase the ERα:ERβ ratio and a reduction in the activity of the p53 tumor suppressor protein. PMID:20974639

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Qin; Han, Fei; Peng, Shi

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 inducedmore » 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 expression. • Nur77 overexpression inhibited oxLDL-induced cell viability, production of apoptotic bodies and restored DNA synthesis. • Cell viability, CyclinA2 and PCNA expression and cell apoptosis were mediated through the p38 MAPK signaling pathway. • Nur77 overexpression mediated the expression of genes PCNA, p21, and caspase-3.« less

Anti-inflammatory effect of cannabinoid agonist WIN55, 212 on mouse experimental colitis is related to inhibition of p38MAPK

PubMed Central

Feng, Ya-Jing; Li, Yong-Yu; Lin, Xu-Hong; Li, Kun; Cao, Ming-Hua

2016-01-01

AIM To investigate the anti-inflammatory effect and the possible mechanisms of an agonist of cannabinoid (CB) receptors, WIN55-212-2 (WIN55), in mice with experimental colitis, so as to supply experimental evidence for its clinical use in future. METHODS We established the colitis model in C57BL/6 mice by replacing the animals’ water supply with 4% dextran sulfate sodium (DSS) for 7 consecutive days. A colitis scoring system was used to evaluate the severity of colon local lesion. The plasma levels of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), and the myeloperoxidase (MPO) activity in colon tissue were measured. The expressions of cannabinoid receptors, claudin-1 protein, p38 mitogen-activated protein kinase (p38MAPK) and its phosphorylated form (p-p38) in colon tissue were determined by immunohistochemistry and Western blot. In addition, the effect of SB203580 (SB), an inhibitor of p38, was investigated in parallel experiments, and the data were compared with those from intervention groups of WIN55 and SB alone or used together. RESULTS The results demonstrated that WIN55 or SB treatment alone or together improved the pathological changes in mice with DSS colitis, decreased the plasma levels of TNF-α, and IL-6, and MPO activity in colon. The enhanced expression of claudin-1 and the inhibited expression of p-p38 in colon tissues were found in the WIN55-treated group. Besides, the expression of CB1 and CB2 receptors was enhanced in the colon after the induction of DSS colitis, but reduced when p38MAPK was inhibited. CONCLUSION These results confirmed the anti-inflammatory effect and protective role of WIN55 on the mice with experimental colitis, and revealed that this agent exercises its action at least partially by inhibiting p38MAPK. Furthermore, the results showed that SB203580, affected the expression of CB1 and CB2 receptors in the mouse colon, suggesting a close linkage and cross-talk between the p38MAPK signaling pathway and the endogenous CB system. PMID:27920472

Iron overload may promote alteration of NK cells and hematopoietic stem/progenitor cells by JNK and P38 pathway in myelodysplastic syndromes.

PubMed

Hua, Yanni; Wang, Chaomeng; Jiang, Huijuan; Wang, Yihao; Liu, Chunyan; Li, Lijuan; Liu, Hui; Shao, Zonghong; Fu, Rong

2017-08-01

The objective of the study was to examine levels of intracellular iron, reactive oxygen species (ROS) and the expression of JNK and p38MAPK in NK cells and hematopoietic stem/progenitor cells (HSPCs) in MDS patients, and explore potential mechanisms by which iron overload (IOL) promotes MDS progression. Thirty-four cases of MDS and six cases of AML transformed from MDS (MDS/AML) were included. HSPCs and NK cells were isolated by magnetic absorption cell sorting. We used flow cytometry to detect the levels of ROS and intracellular JNK and P38 in NK cells and HSPCs. Total RNA and protein were extracted from NK cells and CD34 + cells to examine the expression of JNK and p38MAPK using RT-PCR and Western blotting. Intracellular iron concentration was detected. Data were analyzed by SPSS 21 statistical software. Intracellular iron concentration and ROS were increased in both NK cells and HSPCs in MDS patients with iron overload (P < 0.05). MDS patients with iron overload had higher JNK expression and lower p38 expression in NK cells, and higher p38 expression in HSPCs compared with non-iron overload group. IOL may cause alterations in NK cells and HSPCs through the JNK and p38 pathways, and play a role in the transformation to AML from MDS.

Anti-Proliferative Effects of Rutin on OLETF Rat Vascular Smooth Muscle Cells Stimulated by Glucose Variability

PubMed Central

Yu, Sung Hoon; Yu, Jae Myung; Lee, Seong Jin; Kang, Dong Hyun; Cho, Young Jung; Kim, Doo Man

2016-01-01

Purpose Proliferation of vascular smooth muscle cells (VSMCs) plays a crucial role in atherosclerosis. Rutin is a major representative of the flavonol subclass of flavonoids and has various pharmacological activities. Currently, data are lacking regarding its effects on VSMC proliferation induced by intermittent hyperglycemia. Here, we demonstrate the effects of rutin on VSMC proliferation and migration according to fluctuating glucose levels. Materials and Methods Primary cultures of male Otsuka Long-Evans Tokushima Fatty (OLETF) rat VSMCs were obtained from enzymatically dissociated rat thoracic aortas. VSMCs were incubated for 72 h with alternating normal (5.5 mmol/L) and high (25.0 mmol/L) glucose media every 12 h. Proliferation and migration of VSMCs, the proliferative molecular pathway [including p44/42 mitogen-activated protein kinases (MAPK), mitogen-activated protein kinase kinase 1/2 (MEK1/2), p38 MAPK, phosphoinositide 3-kinase (PI3K), c-Jun N-terminal protein kinase (JNK), nuclear factor kappa B (NF-κB), and Akt], the migratory pathway (big MAPK 1, BMK1), reactive oxygen species (ROS), and apoptotic pathway were analyzed. Results We found enhanced proliferation and migration of VSMCs when cells were incubated in intermittent high glucose conditions, compared to normal glucose. These effects were lowered upon rutin treatment. Intermittent treatment with high glucose for 72 h increased the expression of phospho-p44/42 MAPK (extracellular signal regulated kinase 1/2, ERK1/2), phospho-MEK1/2, phospho-PI3K, phospho-NF-κB, phospho-BMK1, and ROS, compared to treatment with normal glucose. These effects were suppressed by rutin. Phospho-p38 MAPK, phospho-Akt, JNK, and apoptotic pathways [B-cell lymphoma (Bcl)-xL, Bcl-2, phospho-Bad, and caspase-3] were not affected by fluctuations in glucose levels. Conclusion Fluctuating glucose levels increased proliferation and migration of OLETF rat VSMCs via MAPK (ERK1/2), BMK1, PI3K, and NF-κB pathways. These effects were inhibited by the antioxidant rutin. PMID:26847289

Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis.

PubMed

Yang, Jung-Bo; Quan, Juan-Hua; Kim, Ye-Eun; Rhee, Yun-Ee; Kang, Byung-Hyun; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min; Lee, Young-Ha

2015-08-01

Trichomonas vaginalis; induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in TNF-α production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased TNF-α production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, TNF-α production was significantly decreased compared to the control; however, TNF-α reduction patterns were different depending on the type of PI3K/MAPK inhibitors. TNF-α production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of TNF-α production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.

Role of Phosphatidylinositol-3 Kinase Pathway in NMDA Preconditioning: Different Mechanisms for Seizures and Hippocampal Neuronal Degeneration Induced by Quinolinic Acid.

PubMed

Constantino, Leandra C; Binder, Luisa B; Vandresen-Filho, Samuel; Viola, Giordano G; Ludka, Fabiana K; Lopes, Mark W; Leal, Rodrigo B; Tasca, Carla I

2018-04-20

N-methyl D-aspartate (NMDA) preconditioning is evoked by the administration of a subtoxic dose of NMDA and is protective against neuronal excitotoxicity. This effect may involve a diversity of targets and cell signaling cascades associated to neuroprotection. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt) and mitogen-activated protein kinases (MAPKs) such as extracellular regulated protein kinase 1/2 (ERK1/2) and p38 MAPK pathways play a major role in neuroprotective mechanisms. However, their involvement in NMDA preconditioning was not yet fully investigated. The present study aimed to evaluate the effect of NMDA preconditioning on PI3K/Akt, ERK1/2, and p38 MAPK pathways in the hippocampus of mice and characterize the involvement of PI3K on NMDA preconditioning-evoked prevention of seizures and hippocampal cell damage induced by quinolinic acid (QA). Thus, mice received wortmannin (a PI3K inhibitor) and 15 min later a subconvulsant dose of NMDA (preconditioning) or saline. After 24 h of this treatment, an intracerebroventricular QA infusion was administered. Phosphorylation levels and total content of Akt, glycogen synthase protein kinase-3β (GSK-3β), ERK1/2, and p38 MAPK were not altered after 24 h of NMDA preconditioning with or without wortmmanin pretreatment. Moreover, after QA administration, behavioral seizures, hippocampal neuronal degeneration, and Akt activation were evaluated. Inhibition of PI3K pathway was effective in abolishing the protective effect of NMDA preconditioning against QA-induced seizures, but did not modify neuronal protection promoted by preconditioning as evaluated by Fluoro-Jade B staining. The study confirms that PI3K participates in the mechanism of protection induced by NMDA preconditioning against QA-induced seizures. Conversely, NMDA preconditioning-evoked protection against neuronal degeneration is not altered by PI3K signaling pathway inhibition. These results point to differential mechanisms regarding protection against a behavioral and cellular manifestation of neural damage.

An intracellular signaling hierarchy determines direction of migration in opposing chemotactic gradients.

PubMed

Heit, Bryan; Tavener, Samantha; Raharjo, Eko; Kubes, Paul

2002-10-14

Neutrophils must follow both endogenous and bacterial chemoattractant signals out of the vasculature and through the interstitium to arrive at a site of infection. By necessity, in the setting of multiple chemoattractants, the neutrophils must prioritize, favoring end target chemoattractants (e.g., fMLP and C5a) emanating from the site of infection over intermediary endogenous chemoattractants (e.g., IL-8 and LTB4) encountered en route to sites of infection. In this study, we propose a hierarchical model of two signaling pathways mediating the decision-making process of the neutrophils, which allows end target molecules to dominate over intermediary chemoattractants. In an under agarose assay, neutrophils predominantly migrated toward end target chemoattractants via p38 MAPK, whereas intermediary chemoattractant-induced migration was phosphoinositide 3-kinase (PI3K)/Akt dependent. When faced with competing gradients of end target and intermediary chemoattractants, Akt activation was significantly reduced within neutrophils, and the cells migrated preferentially toward end target chemoattractants even at 1/1,000th that of intermediary chemoattractants. End target molecules did not require chemotactic properties, since the p38 MAPK activator, LPS, also inhibited Akt and prevented migration to intermediary chemoattractants. p38 MAPK inhibitors not only reversed this hierarchy, such that neutrophils migrated preferentially toward intermediary chemoattractants, but also allowed neutrophils to be drawn out of a local end target chemoattractant environment and toward intermediary chemoattractants unexpectedly in an exaggerated (two- to fivefold) fashion. This was entirely related to significantly increased magnitude and duration of Akt activation. Finally, end target chemoattractant responses were predominantly Mac-1 dependent, whereas nondominant chemoattractants used primarily LFA-1. These data provide support for a two pathway signaling model wherein the end target chemoattractants activate p38 MAPK, which inhibits intermediary chemoattractant-induced PI3K/Akt pathway, establishing an intracellular signaling hierarchy.

TES inhibits colorectal cancer progression through activation of p38.

PubMed

Li, Huili; Huang, Kun; Gao, Lu; Wang, Lixia; Niu, Yanfeng; Liu, Hongli; Wang, Zheng; Wang, Lin; Wang, Guobin; Wang, Jiliang

2016-07-19

The human TESTIN (TES) gene has been identified as a candidate tumor suppressor based on its location at a common fragile site - a region where loss of heterozygosity has been detected in numerous types of tumors. To investigate its role in colorectal cancer (CRC), we examined TES protein levels in CRC tissue samples and cell lines. We observed that TES was markedly reduced in both CRC tissue and cell lines. Additionally, overexpression of TES significantly inhibited cell proliferation, migration, and invasion, while increasing cell apoptosis in colon cancer cells. By contrast, shRNA-mediated TES knockdown elicited the opposite effects. TES inhibited the progression of CRC by up-regulating pro-apoptotic proteins, down-regulating anti-apoptotic proteins, and simultaneously activating p38 mitogen-activated protein kinase (MAPK) signaling pathways. Collectively, these data indicate that TES functions as a necessary suppressor of CRC progression by activating p38-MAPK signaling pathways. This suggests that TES may have a potential application in CRC diagnosis and targeted gene therapy.

TES inhibits colorectal cancer progression through activation of p38

PubMed Central

Gao, Lu; Wang, Lixia; Niu, Yanfeng; Liu, Hongli; Wang, Zheng; Wang, Lin; Wang, Guobin; Wang, Jiliang

2016-01-01

The human TESTIN (TES) gene has been identified as a candidate tumor suppressor based on its location at a common fragile site – a region where loss of heterozygosity has been detected in numerous types of tumors. To investigate its role in colorectal cancer (CRC), we examined TES protein levels in CRC tissue samples and cell lines. We observed that TES was markedly reduced in both CRC tissue and cell lines. Additionally, overexpression of TES significantly inhibited cell proliferation, migration, and invasion, while increasing cell apoptosis in colon cancer cells. By contrast, shRNA-mediated TES knockdown elicited the opposite effects. TES inhibited the progression of CRC by up-regulating pro-apoptotic proteins, down-regulating anti-apoptotic proteins, and simultaneously activating p38 mitogen-activated protein kinase (MAPK) signaling pathways. Collectively, these data indicate that TES functions as a necessary suppressor of CRC progression by activating p38-MAPK signaling pathways. This suggests that TES may have a potential application in CRC diagnosis and targeted gene therapy. PMID:27323777

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

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

PubMed

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

2014-03-01

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

p38 MAPK activation and H3K4 trimethylation is decreased by lactate in vitro and high intensity resistance training in human skeletal muscle.

PubMed

Willkomm, Lena; Gehlert, Sebastian; Jacko, Daniel; Schiffer, Thorsten; Bloch, Wilhelm

2017-01-01

Exercise induces adaptation of skeletal muscle by acutely modulating intracellular signaling, gene expression, protein turnover and myogenic activation of skeletal muscle stem cells (Satellite cells, SCs). Lactate (La)-induced metabolic stimulation alone has been shown to modify SC proliferation and differentiation. Although the mechanistic basis remains elusive, it was demonstrated that La affects signaling via p38 mitogen activated protein kinase (p38 MAPK) which might contribute to trimethylation of histone 3 lysine 4 (H3K4me3) known to regulate satellite cell proliferation and differentiation. We investigated the effects of La on p38 MAPK and H3K4me3 in a model of activated SCs. Differentiating C2C12 myoblasts were treated with La (20 mM) and samples analysed using qRT-PCR, immunofluorescence, and western blotting. We determined a reduction of p38 MAPK phosphorylation, decreased H3K4me3 and reduced expression of Myf5, myogenin, and myosin heavy chain (MHC) leading to decreased differentiation of La-treated C2C12 cells after 5 days of repeated La treatment. We further investigated whether this regulatory pathway would be affected in human skeletal muscle by the application of two different resistance exercise regimes (RE) associated with distinct metabolic demands and blood La accumulation. Muscle biopsies were obtained 15, 30 min, 1, 4, and 24 h post exercise after moderate intensity RE (STD) vs. high intensity RE (HIT). Consistent with in vitro results, reduced p38 phosphorylation and blunted H3K4me3 were also observed upon metabolically demanding HIT RE in human skeletal muscle. Our data provide evidence that La-accumulation acutely affects p38 MAPK signaling, gene expression and thereby cell differentiation and adaptation in vitro, and likely in vivo.

p38 MAPK-Mediated Bmi-1 Down-Regulation and Defective Proliferation in ATM-Deficient Neural Stem Cells Can Be Restored by Akt Activation

PubMed Central

Kim, Jeesun; Hwangbo, Jeon; Wong, Paul K. Y.

2011-01-01

A-T (ataxia telangiectasia) is a genetic disease caused by a mutation in the Atm (A-T mutated) gene that leads to neurodegeneration. Despite an increase in the numbers of studies in this area in recent years, the mechanisms underlying neurodegeneration in human A-T are still poorly understood. Previous studies demonstrated that neural stem cells (NSCs) isolated from the subventricular zone (SVZ) of Atm -/- mouse brains show defective self-renewal and proliferation, which is accompanied by activation of chronic p38 mitogen-activated protein kinase (MAPK) and a lower level of the polycomb protein Bmi-1. However, the mechanism underlying Bmi-1 down-regulation and its relevance to defective proliferation in Atm-/- NSCs remained unclear. Here, we show that over-expression of Bmi-1 increases self-renewal and proliferation of Atm-/- NSCs to normal, indicating that defective proliferation in Atm-/- NSCs is a consequence of down-regulation of Bmi-1. We also demonstrate that epidermal growth factor (EGF)-induced Akt phosphorylation renders Bmi-1 resistant to the proteasomal degradation, leading to its stabilization and accumulation in the nucleus. However, inhibition of the Akt-dependent Bmi-1 stabilizing process by p38 MAPK signaling reduces the levels of Bmi-1. Treatment of the Atm-/- NSCs with a specific p38 MAPK inhibitor SB203580 extended Bmi-1 posttranscriptional turnover and H2A ubiquitination in Atm-/- NSCs. Our observations demonstrate the molecular basis underlying the impairment of self-renewal and proliferation in Atm-/- NSCs through the p38 MAPK-Akt-Bmi-1-p21 signaling pathway. PMID:21305053

Metadherin facilitates podocyte apoptosis in diabetic nephropathy

PubMed Central

Liu, Wen-Ting; Peng, Fen-Fen; Li, Hong-Yu; Chen, Xiao-Wen; Gong, Wang-Qiu; Chen, Wen-Jing; Chen, Yi-Hua; Li, Pei-Lin; Li, Shu-Ting; Xu, Zhao-Zhong; Long, Hai-Bo

2016-01-01

Apoptosis, one of the major causes of podocyte loss, has been reported to have a vital role in diabetic nephropathy (DN) pathogenesis, and understanding the mechanisms underlying the regulation of podocyte apoptosis is crucial. Metadherin (MTDH) is an important oncogene, which is overexpressed in most cancers and responsible for apoptosis, metastasis, and poor patient survival. Here we show that the expression levels of Mtdh and phosphorylated p38 mitogen-activated protein kinase (MAPK) are significantly increased, whereas those of the microRNA-30 family members (miR-30s) are considerably reduced in the glomeruli of DN rat model and in high glucose (HG)-induced conditionally immortalized mouse podocytes (MPC5). These levels are positively correlated with podocyte apoptosis rate. The inhibition of Mtdh expression, using small interfering RNA, but not Mtdh overexpression, was shown to inhibit HG-induced MPC5 apoptosis and p38 MAPK pathway, and Bax and cleaved caspase 3 expression. This was shown to be similar to the effects of p38 MAPK inhibitor (SB203580). Furthermore, luciferase assay results demonstrated that Mtdh represents the target of miR-30s. Transient transfection experiments, using miR-30 microRNA (miRNA) inhibitors, led to the increase in Mtdh expression and induced the apoptosis of MPC5, whereas the treatment with miR-30 miRNA mimics led to the reduction in Mtdh expression and apoptosis of HG-induced MPC5 cells in comparison with their respective controls. Our results demonstrate that Mtdh is a potent modulator of podocyte apoptosis, and that it represents the target of miR-30 miRNAs, facilitating podocyte apoptosis through the activation of HG-induced p38 MAPK-dependent pathway. PMID:27882943

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.

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

PubMed

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

2017-03-15

Adipose tissue inflammation and oxidative stress are key components in the development of obesity and insulin resistance. Heme oxygenase (HO)-1 in adipocytes protects against obesity and adipose dysfunction. In this study, we report the identification of butein, a flavonoid chalcone, as a novel inducer of HO-1 expression in adipocytes in vitro and in vivo. Butein upregulated HO-1 mRNA and protein expression in 3T3-L1 adipocytes, accompanied by Kelch-Like ECH-Associated Protein (Keap) 1 degradation and increase in the nuclear level of nuclear factor erythroid 2-related factor 2 (Nrf2). Butein modulation of Keap1 and Nrf2 as well as HO-1 upregulation was reversed by pretreatment with p38 MAPK inhibitor SB203580, indicating the involvement of p38 MAPK in butein activation of Nrf2 in adipocytes. In addition, HO-1 activation by butein led to the inhibitions of reactive oxygen species and adipocyte differentiation, as evidenced by the fact that butein repression of reactive oxygen species and adipogenesis was reversed by pretreatment with HO-1 inhibitor SnPP. Induction of HO-1 expression by butein was also demonstrated in the adipose tissue of C57BL/6 mice fed a high-fat diet administered along with butein for three weeks, and correlated with the inhibitions of adiposity and adipose tissue inflammation, which were reversed by co-administration of SnPP. Altogether, our results demonstrate that butein activates the p38 MAPK/Nrf2/HO-1 pathway to act as a potent inhibitor of adipose hypertrophy and inflammation in a diet-induced obesity model and thus has potential for suppressing obesity-linked metabolic syndrome. Copyright © 2017 Elsevier B.V. All rights reserved.

Ischemic time impacts biological integrity of phospho-proteins in PI3K/Akt, Erk/MAPK, and p38 MAPK signaling networks.

PubMed

Holzer, Timothy R; Fulford, Angie D; Arkins, Austin M; Grondin, Janet M; Mundy, Christopher W; Nasir, Aejaz; Schade, Andrew E

2011-06-01

Post-translational modifications of proteins, such as phosphorylation, are labile events dynamically regulated by opposing kinase and phosphatase activities. Preanalytical factors, such as ischemic time before fixation, affect these activities and can have a significant impact on the ability to elucidate signaling pathways in tissue. Immunohistochemical analysis of phosphorylated proteins involved in PI3K/Akt, Erk/MAPK, and p38 MAPK signaling networks was performed in human cell line xenografts from lung, brain, ovary, and prostate tumors. In order to replicate real-world practices, the tissues were subjected to ischemic times of 0 (baseline), 1, 4, and 24 hours before fixation in formalin. Two key concepts emerge from this analysis: (1) the stability of different phospho-epitopes within a given tumor type is variable (e.g. phospho-PRAS40 is more labile than phospho-S6 ribosomal protein) and (2) the stability of a given phospho-epitope (e.g. phospho-MAPKAPK2) varies significantly across different tumor types. These results highlight the importance of proper tissue acquisition and rapid fixation to preserve the biological integrity of signal transduction pathways that may guide therapeutic decision making.

Early Secreted Antigenic Target of 6 kDa of Mycobacterium tuberculosis Stimulates Macrophage Chemoattractant Protein-1 Production by Macrophages and Its Regulation by p38 Mitogen-Activated Protein Kinases and Interleukin-4.

PubMed

Ma, J; Jung, B-G; Yi, N; Samten, B

2016-07-01

Early secreted antigenic target of 6 kDa (ESAT-6), the major virulence factor of Mycobacterium tuberculosis, affects host immunity and the formation of granulomas likely through inflammatory cytokines. To understand its role in this regard further, we investigated the effect of ESAT-6 on macrophages by determining the production of macrophage chemoattractant protein (MCP)-1, a major chemokine associated with tuberculosis pathogenesis, by murine bone marrow-derived macrophages (BMDMs) and its regulation by protein kinases and cytokines. The results revealed that ESAT-6, but not Ag85A and culture filtrate protein 10 kDa (CFP10), induced MCP-1 production by BMDMs dose and time dependently. Inhibition of p38 but not other mitogen-activated protein kinases (MAPK) and PI3K further enhanced ESAT-6-induced MCP-1 production by BMDMs. Inhibition of p38 MAPK enhanced ESAT-6-induced MCP-1 mRNA accumulation without affecting mRNA stability. ESAT-6 also induced TNF-α from BMDMs and MCP-1 from mouse lung epithelial cells, and these were suppressed by p38 MAPK inhibition, implying cytokine- and cell-specific effect of p38 MAPK inhibition on ESAT-6-induced MCP-1 by macrophages. Pretreatment of BMDMs with IL-4, but not other cytokines (IL-2, IL-10, TNF-α, IFN-γ and IL-1α) further elevated ESAT-6-stimulated MCP-1 production although IL-4 did not induce MCP-1 without ESAT-6. Both p38 MAPK inhibitor and IL-4 did not show additive effect on ESAT-6-induced MCP-1 protein level despite such effect on MCP-1 mRNA level was evident. In conclusion, these results indicate a specific role for both p38 MAPK and IL-4 in ESAT-6-induced MCP-1 production by macrophages and suggest a pathway with significance in tuberculosis pathogenesis. © 2016 The Foundation for the Scandinavian Journal of Immunology.

IL-17A induces eotaxin-1/CC chemokine ligand 11 expression in human airway smooth muscle cells: role of MAPK (Erk1/2, JNK, and p38) pathways.

PubMed

Rahman, Muhammad Shahidur; Yamasaki, Akira; Yang, Jie; Shan, Lianyu; Halayko, Andrew J; Gounni, Abdelilah Soussi

2006-09-15

Recently, IL-17A has been shown to be expressed in higher levels in respiratory secretions from asthmatics and correlated with airway hyperresponsiveness. Although these studies raise the possibility that IL-17A may influence allergic disease, the mechanisms remain unknown. In this study, we investigated the molecular mechanisms involved in IL-17A-mediated CC chemokine (eotaxin-1/CCL11) production from human airway smooth muscle (ASM) cells. We found that incubation of human ASM cells with rIL-17A resulted in a significant increase of eotaxin-1/CCL11 release from ASM cells that was reduced by neutralizing anti-IL-17A mAb. Moreover, IL-17A significantly induced eotaxin-1/CCL11 release and mRNA expression, an effect that was abrogated with cycloheximide and actinomycin D treatment. Furthermore, transfection studies using a luciferase-driven reporter construct containing eotaxin-1/CCL11 proximal promoter showed that IL-17A induced eotaxin-1/CCL11 at the transcriptional level. IL-17A also enhanced significantly IL-1beta-mediated eotaxin-1/CCL11 mRNA, protein release, and promoter activity in ASM cells. Primary human ASM cells pretreated with inhibitors of MAPK p38, p42/p44 ERK, JNK, or JAK but not PI3K, showed a significant decrease in eotaxin-1/CCL11 release upon IL-17A treatment. In addition, IL-17A mediated rapid phosphorylation of MAPK (p38, JNK, and p42/44 ERK) and STAT-3 but not STAT-6 or STAT-5 in ASM cells. Taken together, our data provide the first evidence of IL-17A-induced eotaxin-1/CCL11 expression in ASM cells via MAPK (p38, p42/p44 ERK, JNK) signaling pathways. Our results raise the possibility that IL-17A may play a role in allergic asthma by inducing eotaxin-1/CCL11 production.

Constitutive activation of MAPK cascade in acute quadriplegic myopathy.

PubMed

Di Giovanni, Simone; Molon, Annamaria; Broccolini, Aldobrando; Melcon, Gisela; Mirabella, Massimiliano; Hoffman, Eric P; Servidei, Serenella

2004-02-01

Acute quadriplegic myopathy (AQM; also called "critical illness myopathy") shows acute muscle wasting and weakness and is experienced by some patients with severe systemic illness, often associated with administration of corticosteroids and/or neuroblocking agents. Key aspects of AQM include muscle atrophy and myofilament loss. Although these features are shared with neurogenic atrophy, myogenic atrophy in AQM appears mechanistically distinct from neurogenic atrophy. Using muscle biopsies from AQM, neurogenic atrophy, and normal controls, we show that both myogenic and neurogenic atrophy share induction of myofiber-specific ubiquitin/proteosome pathways (eg, atrogin-1). However, AQM patient muscle showed a specific strong induction of transforming growth factor (TGF)-beta/MAPK pathways. Atrophic AQM myofibers showed coexpression of TGF-beta receptors, p38 MAPK, c-jun, and c-myc, including phosphorylated active forms, and these same fibers showed apoptotic features. Our data suggest a model of AQM pathogenesis in which stress stimuli (sepsis, corticosteroids, pH imbalance, osmotic imbalance) converge on the TGF-beta pathway in myofibers. The acute stimulation of the TGF-beta/MAPK pathway, coupled with the inactivity-induced atrogin-1/proteosome pathway, leads to the acute muscle loss seen in AQM patients.

Cloning and characterization of microbial activated Aedes aegypti MEK4 (AaMEK4): influences of noncatalytic domains on enzymatic activity.

PubMed

Wu, R C-C; Cho, W-L

2014-10-01

Protein kinases are known to be involved in a number of signal transduction cascades. Both the stress-activated Jun N-terminal kinase (JNK) and mitogen-activated protein kinase (MAPK) p38 pathways have been shown to correlate with the insect immune response to microbial infection. MAP kinase kinase 4 (MEK4) is an upstream kinase of JNK and p38 kinase. The cDNA of AaMEK4 was cloned and characterized. AaMEK4 was activated by microbial lysates of Gram-positive, Gram-negative bacteria and yeast. The conserved lysine (K112 ) and the putative phosphorylation sites (S238 and T242 ) were shown to be important for kinase activity by site-directed mutagenesis. A common MAPK docking site (MAPK_dsA) was found and in addition, a new nearby docking site, MAPK_dsB, was identified in the N-terminal noncatalytic domain of AaMEK4. MAPK_dsB was shown to be a unique element in the MEK4 family. In this study, both MAPK_dsA and _dsB were demonstrated to be important to AaMEK4 enzymatic activity for the downstream protein kinase, Aap38. © 2014 The Royal Entomological Society.

Naja nigricollis CMS-9 enhances the mitochondria-mediated death pathway in adaphostin-treated human leukaemia U937 cells.

PubMed

Chen, Ying-Jung; Wang, Jeh-Jeng; Chang, Long-Sen

2011-11-01

1. The aim of the present study was to explore the effect of the Naja nigricollis phospholipase A(2) CMS-9 on adaphostin-induced death of human leukaemia U937 cells. 2. Leukaemia U937 cells (Bcr/Abl-negative cells) were treated with adaphostin (0-10 μmol/L) and CMS-9 (0-1 μmol/L). The effects of CMS-9, adaphostin and their combination on cell viability, the generation reactive oxygen species (ROS), [Ca(2+) ](i) , p38 mitogen-activated protein kinase (MAPK) activation, Akt and extracellular signal-regulated kinase (ERK) inactivation, mitochondrial membrane potential (ΔΨ(m) ) and Bcl-2 family proteins were analysed. 3. Both adaphostin and CMS-9 induced U937 cell apoptosis, characterized by dissipation of ΔΨ(m) and ROS generation. Combined treatment further increased ΔΨ(m) loss and reduced the viability of adaphostin-treated cells. Unlike in CMS-9-treated cells, in adaphostin-treated cells ROS-induced increases in [Ca(2+) ](i) were observed. CMS-9-induced ROS generation resulted in p38 MAPK activation, whereas adaphostin treatment elicited ROS/Ca(2+) -mediated inactivation of Akt and ERK. Moreover, Akt was found to be involved in ERK phosphorylation. Suppression of p38 MAPK activation blocked CMS-9-induced ΔΨ(m) loss and Bcl-xL downregulation. Overexpression of constitutively active Akt and mitogen-activated protein kinase kinase (MEK) 1 rescued adaphostin-induced ΔΨ(m) loss and Bcl-2 downregulation. Similarly, CMS-9 augmented adaphostin toxicity in human leukaemia K562 cells via increased mitochondrial alterations. 4. The results suggest that two distinct pathways mediate adaphostin- and CMS-9-induced mitochondrial damage (i.e. the ROS-Ca(2+) -Akt-ERK and ROS-p38 MAPK pathways, respectively). These distinct pathway explain the augmentation by CMS-9 of ΔΨ(m) loss and apoptosis in adaphostin-treated U937 cells. © 2011 The Authors. Clinical and Experimental Pharmacology and Physiology © 2011 Blackwell Publishing Asia Pty Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Seung J.; Kim, Chae E.; Yun, Mi R.

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

A Conditional Knockout Mouse Model Reveals a Critical Role of PKD1 in Osteoblast Differentiation and Bone Development

PubMed Central

Li, Shao; Xu, Wanfu; Xing, Zhe; Qian, Jiabi; Chen, Liping; Gu, Ruonan; Guo, Wenjing; Lai, Xiaoju; Zhao, Wanlu; Li, Songyu; Wang, Yaodong; Wang, Q. Jane; Deng, Fan

2017-01-01

The protein kinase D family of serine/threonine kinases, particularly PKD1, has been implicated in the regulation of a complex array of fundamental biological processes. However, its function and mechanism underlying PKD1-mediated the bone development and osteoblast differentiation are not fully understood. Here we demonstrate that loss of PKD1 function led to impaired bone development and osteoblast differentiation through STAT3 and p38 MAPK signaling using in vitro and in vivo bone-specific conditional PKD1-knockout (PKD1-KO) mice models. These mice developed markedly craniofacial dysplasia, scapula dysplasia, long bone length shortage and body weight decrease compared with wild-type littermates. Moreover, deletion of PKD1 in vivo reduced trabecular development and activity of osteoblast development, confirmed by Micro-CT and histological staining as well as expression of osteoblastic marker (OPN, Runx2 and OSX). Mechanistically, loss of PKD1 mediated the downregulation of osteoblast markers and impaired osteoblast differentiation through STAT3 and p38 MAPK signaling pathways. Taken together, these results demonstrated that PKD1 contributes to the osteoblast differentiation and bone development via elevation of osteoblast markers through activation of STAT3 and p38 MAPK signaling pathways. PMID:28084409

Lysyl Oxidase Induces Vascular Oxidative Stress and Contributes to Arterial Stiffness and Abnormal Elastin Structure in Hypertension: Role of p38MAPK.

PubMed

Martínez-Revelles, Sonia; García-Redondo, Ana B; Avendaño, María S; Varona, Saray; Palao, Teresa; Orriols, Mar; Roque, Fernanda R; Fortuño, Ana; Touyz, Rhian M; Martínez-González, Jose; Salaices, Mercedes; Rodríguez, Cristina; Briones, Ana M

2017-09-01

Vascular stiffness, structural elastin abnormalities, and increased oxidative stress are hallmarks of hypertension. Lysyl oxidase (LOX) is an elastin crosslinking enzyme that produces H 2 O 2 as a by-product. We addressed the interplay between LOX, oxidative stress, vessel stiffness, and elastin. Angiotensin II (Ang II)-infused hypertensive mice and spontaneously hypertensive rats (SHR) showed increased vascular LOX expression and stiffness and an abnormal elastin structure. Mice over-expressing LOX in vascular smooth muscle cells (TgLOX) exhibited similar mechanical and elastin alterations to those of hypertensive models. LOX inhibition with β-aminopropionitrile (BAPN) attenuated mechanical and elastin alterations in TgLOX mice, Ang II-infused mice, and SHR. Arteries from TgLOX mice, Ang II-infused mice, and/or SHR exhibited increased vascular H 2 O 2 and O 2 .- levels, NADPH oxidase activity, and/or mitochondrial dysfunction. BAPN prevented the higher oxidative stress in hypertensive models. Treatment of TgLOX and Ang II-infused mice and SHR with the mitochondrial-targeted superoxide dismutase mimetic mito-TEMPO, the antioxidant apocynin, or the H 2 O 2 scavenger polyethylene glycol-conjugated catalase (PEG-catalase) reduced oxidative stress, vascular stiffness, and elastin alterations. Vascular p38 mitogen-activated protein kinase (p38MAPK) activation was increased in Ang II-infused and TgLOX mice and this effect was prevented by BAPN, mito-TEMPO, or PEG-catalase. SB203580, the p38MAPK inhibitor, normalized vessel stiffness and elastin structure in TgLOX mice. We identify LOX as a novel source of vascular reactive oxygen species and a new pathway involved in vascular stiffness and elastin remodeling in hypertension. LOX up-regulation is associated with enhanced oxidative stress that promotes p38MAPK activation, elastin structural alterations, and vascular stiffness. This pathway contributes to vascular abnormalities in hypertension. Antioxid. Redox Signal. 27, 379-397.

Lysyl Oxidase Induces Vascular Oxidative Stress and Contributes to Arterial Stiffness and Abnormal Elastin Structure in Hypertension: Role of p38MAPK

PubMed Central

Martínez-Revelles, Sonia; García-Redondo, Ana B.; Avendaño, María S.; Varona, Saray; Palao, Teresa; Orriols, Mar; Roque, Fernanda R.; Fortuño, Ana; Touyz, Rhian M.; Martínez-González, Jose; Salaices, Mercedes

2017-01-01

Abstract Aims: Vascular stiffness, structural elastin abnormalities, and increased oxidative stress are hallmarks of hypertension. Lysyl oxidase (LOX) is an elastin crosslinking enzyme that produces H2O2 as a by-product. We addressed the interplay between LOX, oxidative stress, vessel stiffness, and elastin. Results: Angiotensin II (Ang II)-infused hypertensive mice and spontaneously hypertensive rats (SHR) showed increased vascular LOX expression and stiffness and an abnormal elastin structure. Mice over-expressing LOX in vascular smooth muscle cells (TgLOX) exhibited similar mechanical and elastin alterations to those of hypertensive models. LOX inhibition with β-aminopropionitrile (BAPN) attenuated mechanical and elastin alterations in TgLOX mice, Ang II-infused mice, and SHR. Arteries from TgLOX mice, Ang II-infused mice, and/or SHR exhibited increased vascular H2O2 and O2.− levels, NADPH oxidase activity, and/or mitochondrial dysfunction. BAPN prevented the higher oxidative stress in hypertensive models. Treatment of TgLOX and Ang II-infused mice and SHR with the mitochondrial-targeted superoxide dismutase mimetic mito-TEMPO, the antioxidant apocynin, or the H2O2 scavenger polyethylene glycol-conjugated catalase (PEG-catalase) reduced oxidative stress, vascular stiffness, and elastin alterations. Vascular p38 mitogen-activated protein kinase (p38MAPK) activation was increased in Ang II-infused and TgLOX mice and this effect was prevented by BAPN, mito-TEMPO, or PEG-catalase. SB203580, the p38MAPK inhibitor, normalized vessel stiffness and elastin structure in TgLOX mice. Innovation: We identify LOX as a novel source of vascular reactive oxygen species and a new pathway involved in vascular stiffness and elastin remodeling in hypertension. Conclusion: LOX up-regulation is associated with enhanced oxidative stress that promotes p38MAPK activation, elastin structural alterations, and vascular stiffness. This pathway contributes to vascular abnormalities in hypertension. Antioxid. Redox Signal. 27, 379–397. PMID:28010122

Aqueous extract of Taxus chinensis (Pilger) Rehd inhibits lung carcinoma A549 cells through the epidermal growth factor receptor/mitogen-activated protein kinase pathway in vitro and in vivo.

PubMed

Shu, Qijin; Shen, Minhe; Wang, Binbin; Cui, Qingli; Zhou, Xiaoying; Zhu, Luming

2014-06-01

To explore the anticancer mechanism of aqueous extract of Taxus Chinensis (Pilger) Rehd (AETC). The serum pharmacological method was used to avoid interference from administration of the crude medicinal herbs. Eight purebred New Zealand rabbits were used for preparation of serum containing various concentrations of AETC. Forty-eight Balb/c-nu mice were used for in vivo experiments. The effects of serum containing AETC on the proliferation of A549 cells and expression levels of the epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) pathway-related proteins in vitro were investigated. Additionally, the effects on the growth of A549 xenografts in nude mice, and expression levels of the EGFR/MAPK pathway-related proteins in the xenografts, were investigated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that the serum containing AETC significantly decreased the viability of A549 cells in a dose-dependent manner. Western blot showed that the serum containing various concentrations of AETC strongly reduced the levels of phospho-Jun N-terminal kinase (p-JNK) and phospho-extracellular signal-regulated kinasel/2 (ERK1/2) while it increased the level of p-p38. However, no significant effects on the expression levels of JNK, ERK1/2, and p38 MAPK were found. In addition, an anticancer effect from AETC was observed in vivo in the Balb/c-nu mice bearing A549 xenografts. AETC has significant effects on the growth of A549 xenografts and on the activity of the EGFR/MAPK pathway. Therefore, AETC may be beneficial in lung carcinoma treatment.

Promotion of osteointegration under diabetic conditions by tantalum coating-based surface modification on 3-dimensional printed porous titanium implants.

PubMed

Wang, Lin; Hu, Xiaofan; Ma, Xiangyu; Ma, Zhensheng; Zhang, Yang; Lu, Yizhao; Li, Xiang; Lei, Wei; Feng, Yafei

2016-12-01

Clinical evidence indicates a high failure rate for titanium implants (TiI) in diabetic patients, involving the overproduction of reactive oxygen species (ROS) at the implant/bone interface. Tantalum coating on titanium (TaTi) has exerted better tissue integration properties than TiI, but its biological performance under diabetic conditions remains elusive. To investigate whether TaTi may ameliorate diabetes-induced implant destabilization and the underlying mechanisms, primary rabbit osteoblasts cultured on 3-dimensional printed TiI and TaTi were exposed to normal serum (NS), diabetic serum (DS), DS+NAC (a potent ROS inhibitor), and DS+SB203580 (a specific p38 MAPK inhibitor). An in vivo study was performed on diabetic sheep implanted with TiI or TaTi. Diabetes induced mitochondrial-derived ROS overproduction and caused cellular dysfunction and apoptosis, together with the activation of p38 MAPK in osteoblasts on TiI surface. Importantly, TaTi significantly attenuated ROS production and p38 MAPK phosphorylation and exerted more osseointegrative cell behavior than TiI, as shown by improved osteoblast adhesion, increased cell proliferation and differentiation and decreased apoptosis. These results were confirmed in vivo by the enhanced bone healing efficacy of TaTi. Moreover, treatment with NAC or SB203580 on TiI not only inhibited the activation of p38 MAPK but also improved cell function and alleviated apoptotic injury, whereas TaTi combined with NAC or SB203580 failed to further improve osteoblast functional recovery compared with TaTi alone. These results demonstrated that the tantalum coating markedly improved diabetes-induced impaired osteogenesis of TiI, which may be attributed to the suppression of the ROS-mediated p38 MAPK pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

Phospholipase D1 increases Bcl-2 expression during neuronal differentiation of rat neural stem cells.

PubMed

Park, Shin-Young; Ma, Weina; Yoon, Sung Nyo; Kang, Min Jeong; Han, Joong-Soo

2015-01-01

We studied the possible role of phospholipase D1 (PLD1) in the neuronal differentiation, including neurite formation of neural stem cells. PLD1 protein and PLD activity increased during neuronal differentiation. Bcl-2 also increased. Downregulation of PLD1 by transfection with PLD1 siRNA or a dominant-negative form of PLD1 (DN-PLD1) inhibited both neurite outgrowth and Bcl-2 expression. PLD activity was dramatically reduced by a PLCγ (phospholipase Cγ) inhibitor (U73122), a Ca(2+)chelator (BAPTA-AM), and a PKCα (protein kinase Cα) inhibitor (RO320432). Furthermore, treatment with arachidonic acid (AA) which is generated by the action of PLA2 (phospholipase A2) on phosphatidic acid (a PLD1 product), increased the phosphorylation of p38 MAPK and CREB, as well as Bcl-2 expression, indicating that PLA2 is involved in the differentiation process resulting from PLD1 activation. PGE2 (prostaglandin E2), a cyclooxygenase product of AA, also increased during neuronal differentiation. Moreover, treatment with PGE2 increased the phosphorylation of p38 MAPK and CREB, as well as Bcl-2 expression, and this effect was inhibited by a PKA inhibitor (Rp-cAMP). As expected, inhibition of p38 MAPK resulted in loss of CREB activity, and when CREB activity was blocked with CREB siRNA, Bcl-2 production also decreased. We also showed that the EP4 receptor was required for the PKA/p38MAPK/CREB/Bcl-2 pathway. Taken together, these observations indicate that PLD1 is activated by PLCγ/PKCα signaling and stimulate Bcl-2 expression through PLA2/Cox2/EP4/PKA/p38MAPK/CREB during neuronal differentiation of rat neural stem cells.

Vascular Endothelial Growth Factor Receptor-2 Couples Cyclo-Oxygenase-2 with Pro-Angiogenic Actions of Leptin on Human Endothelial Cells

PubMed Central

Garonna, Elena; Botham, Kathleen M.; Birdsey, Graeme M.; Randi, Anna M.; Gonzalez-Perez, Ruben R.; Wheeler-Jones, Caroline P. D.

2011-01-01

Background The adipocyte-derived hormone leptin influences the behaviour of a wide range of cell types and is now recognised as a pro-angiogenic and pro-inflammatory factor. In the vasculature, these effects are mediated in part through its direct leptin receptor (ObRb)-driven actions on endothelial cells (ECs) but the mechanisms responsible for these activities have not been established. In this study we sought to more fully define the molecular links between inflammatory and angiogenic responses of leptin-stimulated human ECs. Methodology/Principal Findings Immunoblotting studies showed that leptin increased cyclo-oxygenase-2 (COX-2) expression (but not COX-1) in cultured human umbilical vein ECs (HUVEC) through pathways that depend upon activation of both p38 mitogen-activated protein kinase (p38MAPK) and Akt, and stimulated rapid phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2) on Tyr1175. Phosphorylation of VEGFR2, p38MAPK and Akt, and COX-2 induction in cells challenged with leptin were blocked by a specific leptin peptide receptor antagonist. Pharmacological inhibitors of COX-2, the phosphatidylinositol 3-kinase (PI3K)/Akt pathway and p38MAPK abrogated leptin-induced EC proliferation (assessed by quantifying 5-bromo-2′-deoxyuridine incorporation, calcein fluorescence and propidium iodide staining), slowed the increased migration rate of leptin-stimulated cells (in vitro wound healing assay) and inhibited leptin-induced capillary-like tube formation by HUVEC on Matrigel. Inhibition of VEGFR2 tyrosine kinase activity reduced leptin-stimulated p38MAPK and Akt activation, COX-2 induction, and pro-angiogenic EC responses, and blockade of VEGFR2 or COX-2 activities abolished leptin-driven neo-angiogenesis in a chick chorioallantoic membrane vascularisation assay in vivo. Conclusions/Significance We conclude that a functional endothelial p38MAPK/Akt/COX-2 signalling axis is required for leptin's pro-angiogenic actions and that this is regulated upstream by ObRb-dependent activation of VEGFR2. These studies identify a new function for VEGFR2 as a mediator of leptin-stimulated COX-2 expression and angiogenesis and have implications for understanding leptin's regulation of the vasculature in both non-obese and obese individuals. PMID:21533119

Early activation of nSMase2/ceramide pathway in astrocytes is involved in ischemia-associated neuronal damage via inflammation in rat hippocampi

PubMed Central

2013-01-01

Background Ceramide accumulation is considered a contributing factor to neuronal dysfunction and damage. However, the underlying mechanisms that occur following ischemic insult are still unclear. Methods In the present study, we established cerebral ischemia models using four-vessel occlusion and oxygen-glucose deprivation methods. The hippocampus neural cells were subjected to immunohistochemistry and immunofluorescence staining for ceramide and neutral sphingomyelinase 2 (nSMase2) levels; immunoprecipitation and immunoblot analysis for nSMase2, receptor for activated C kinase 1 (RACK1), embryonic ectoderm development (EED), p38 mitogen-activated protein kinase (p38MAPK) and phosphorylated p38MAPK expression; SMase assay for nSMase and acid sphingomyelinase (aSMase) activity; real-time reverse transcription polymerase chain reaction for cytokine expression; and Nissl, microtubule-associated protein 2 and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling staining. Results We found considerable production of ceramide in astrocytes, but not in neurons, during early cerebral ischemia. This was accompanied by the induction of nSMase (but not aSMase) activity in the rat hippocampi. The inhibition of nSMase2 activity effectively reduced ceramide accumulation in astrocytes and alleviated neuronal damage to some extent. Meanwhile, the expression levels of proinflammatory cytokines, including tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and IL-6, were found to be upregulated, which may have played an import role in neuronal damage mediated by the nSMase2/ceramide pathway. Although enhanced binding of nSMase2 with RACK1 and EED were also observed after cerebral ischemia, nSMase2 activity was not blocked by the TNF-α receptor inhibitor through RACK1/EED signaling. p38MAPK, but not protein kinase Cζ or protein phosphatase 2B, was able to induce nSMase2 activation after ischemia. p38MAPK can be induced by A2B adenosine receptor (A2BAR) activity. Conclusions These results indicate that the inhibition of ceramide production in astrocytes by targeting A2BAR/p38MAPK/nSMase2 signaling may represent a viable approach for attenuating inflammatory responses and neuronal damage after cerebral ischemia. PMID:24007266

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

PubMed Central

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

2015-01-01

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

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

PubMed

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

2015-11-01

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

The p38/CYLD Pathway is Involved in Necroptosis Induced by Oxygen-glucose Deprivation Combined with ZVAD in Primary Cortical Neurons.

PubMed

Feng, Tao; Chen, WeiWei; Zhang, CaiYi; Xiang, Jie; Ding, HongMei; Wu, LianLian; Geng, DeQin

2017-08-01

Recently, necroptosis, a form of programmed necrosis, has been widely studied. It has previously been shown that knockout of lysine 63 deubiquitinase CYLD significantly inhibits necroptosis in other cell lines, and serum response factor (SRF) could regulate CYLD gene expression through p38 mitogen-activated protein kinase (p38 MAPK). In the following study, we show oxygen-glucose deprivation (OGD) combined with a caspase inhibitor, ZVAD (OGD/ZVAD), induced CYLD protein expression in a time-dependent manner. Immunofluorescence studies showed that CYLD was localized strongly to the nucleus and weakly to the cytoplasm of neurons. The expression of CYLD in the cytoplasm, but not in the nucleus, was increased significantly upon OGD treatment. SB203580 (a p38 MAPK inhibitor) protected against neuronal injury induced by OGD/ZVAD treatment. More importantly, SB203580 decreased CYLD protein levels by inhibiting SRF phosphorylation and indirectly prevented SRF from binding to a CYLD promoter. We also found that cells with knockdown of SRF by short interfering RNA in a lentivirus vector tolerated OGD/ZVAD-induced necroptosis, when the expression of CYLD protein decreased. The results show that SB203580 prevented necroptosis induced by OGD/ZVAD injury by blocking a p38/CYLD dependent pathway.

CXCR3 chemokine receptor-induced chemotaxis in human airway epithelial cells: role of p38 MAPK and PI3K signaling pathways.

PubMed

Shahabuddin, Syed; Ji, Rong; Wang, Ping; Brailoiu, Eugene; Dun, Na; Yang, Yi; Aksoy, Mark O; Kelsen, Steven G

2006-07-01

Human airway epithelial cells (HAEC) constitutively express the CXC chemokine receptor CXCR3, which regulates epithelial cell movement. In diseases such as chronic obstructive pulmonary disease and asthma, characterized by denudation of the epithelial lining, epithelial cell migration may contribute to airway repair and reconstitution. This study compared the potency and efficacy of three CXCR3 ligands, I-TAC/CXCL11, IP-10/CXCL10, and Mig/CXCL9, as inducers of chemotaxis in HAEC and examined the underlying signaling pathways involved. Studies were performed in cultured HAEC from normal subjects and the 16-HBE cell line. In normal HAEC, the efficacy of I-TAC-induced chemotaxis was 349 +/- 88% (mean +/- SE) of the medium control and approximately one-half the response to epidermal growth factor, a highly potent chemoattractant. In normal HAEC, Mig, IP-10, and I-TAC induced chemotaxis with similar potency and a rank order of efficacy of I-TAC = IP-10 > Mig. Preincubation with pertussis toxin completely blocked CXCR3-induced migration. Of interest, intracellular [Ca(2+)] did not rise in response to I-TAC, IP-10, or Mig. I-TAC induced a rapid phosphorylation (5-10 min) of two of the three MAPKs, i.e., p38 and ERK1/2. Pretreatment of HAEC with the p38 inhibitor SB 20358 or the PI3K inhibitor wortmannin dose-dependently inhibited the chemotactic response to I-TAC. In contrast, the ERK1/2 inhibitor U0126 had no effect on chemotaxis. These data indicate that in HAEC, CXCR3-mediated chemotaxis involves a G protein, which activates both the p38 MAPK and PI3K pathways in a calcium-independent fashion.

Geraniol ameliorates TNBS-induced colitis: Involvement of Wnt/β-catenin, p38MAPK, NFκB, and PPARγ signaling pathways.

PubMed

Soubh, Ayman A; Abdallah, Dalaal M; El-Abhar, Hanan S

2015-09-01

Geraniol, a natural component of plant essential oils, exhibits potent chemopreventive effects in the colon; however, its possible role/mechanisms in experimental colitis have not been elucidated, which is the aim of this study. To fulfill this goal, rats were treated for 11days with geraniol and/or sulfasalazine using a TNBS-induced colitis model. Geraniol significantly hindered the colitis-clinical signs (weight loss, colon edema,ulcerative area, colon/spleen mass indices) and opposed the altered oxidative/nitrosative stress. It restored the depleted total antioxidant capacity and lessened the elevated levels of nitric oxide and lipid peroxide. TNBS induced apoptosis and inflammatory cell infiltration, whereas geraniol curtailed these effects by diminishing the levels of caspase-3, intercellular adhesion molecule-1, and myeloperoxidase. The anti-inflammatory effect was documented by inhibiting the colon contents of prostaglandin E2 and interleukin-1β. In order to delve into the anti-colitic signaling pathways, geraniol inhibited the content/expression of glycogen synthase kinase (GSK)-3β, β-catenin, p38 mitogen activated protein kinase (p38MAPK), and nuclear factor kappa B (NFκB), but upregulated that of peroxisome proliferator activated receptor γ (PPARγ). These effects were comparable to those of sulfasalazine, the standard drug, whereas its combination with geraniol mediated effects that surpassed either treatment alone. Geraniol in the current study improved experimental colitis partly via its antioxidant, anti-inflammatory, and immunosuppressive potentials, possibly by modulating the Wnt/GSK-3β/β-catenin, p38MAPK, NFκB, and PPARγ signaling pathways. The study also revealed that geraniol represents a valuable asset against colitis alone or in combination with the conventional anti-colitic therapies. Copyright © 2015 Elsevier Inc. All rights reserved.

Non-thermal plasma inhibits human cervical cancer HeLa cells invasiveness by suppressing the MAPK pathway and decreasing matrix metalloproteinase-9 expression

NASA Astrophysics Data System (ADS)

Li, Wei; Yu, K. N.; Bao, Lingzhi; Shen, Jie; Cheng, Cheng; Han, Wei

2016-01-01

Non-thermal plasma (NTP) has been proposed as a novel therapeutic method for anticancer treatment. However, the mechanism underlying its biological effects remains unclear. In this study, we investigated the inhibitory effect of NTP on the invasion of HeLa cells, and explored the possible mechanism. Our results showed that NTP exposure for 20 or 40 s significantly suppressed the migration and invasion of HeLa cells on the basis of matrigel invasion assay and wound healing assay, respectively. Moreover, NTP reduced the activity and protein expression of the matrix metalloproteinase (MMP)-9 enzyme. Western blot analysis indicated that NTP exposure effectively decreased phosphorylation level of both ERK1/2 and JNK, but not p38 MAPK. Furthermore, treatment with MAPK signal pathway inhibitors or NTP all exhibited significant depression of HeLa cells migration and MMP-9 expression. The result showed that NTP synergistically suppressed migration and MMP-9 expression in the presence of ERK1/2 inhibitor and JNK inhibitor, but not p38 MAPK inhibitor. Taken together, these findings suggested that NTP exposure inhibited the migration and invasion of HeLa cells via down-regulating MMP-9 expression in ERK1/2 and JNK signaling pathways dependent manner. These findings provide hints to the potential clinical research and therapy of NTP on cervical cancer metastasis.

Naproxen Induces Type X Collagen Expression in Human Bone-Marrow-Derived Mesenchymal Stem Cells Through the Upregulation of 5-Lipoxygenase

PubMed Central

Alaseem, Abdulrahman M.; Madiraju, Padma; Aldebeyan, Sultan A.; Noorwali, Hussain; Antoniou, John

2015-01-01

Several studies have shown that type X collagen (COL X), a marker of late-stage chondrocyte hypertrophy, is expressed in mesenchymal stem cells (MSCs) from osteoarthritis (OA) patients. We recently found that Naproxen, but not other nonsteroidal anti-inflammatory drugs (NSAIDs) (Ibuprofen, Celebrex, Diclofenac), can induce type X collagen gene (COL10A1) expression in bone-marrow-derived MSCs from healthy and OA donors. In this study we determined the effect of Naproxen on COL X protein expression and investigated the intracellular signaling pathways that mediate Naproxen-induced COL10A1 expression in normal and OA hMSCs. MSCs of OA patients were isolated from aspirates from the intramedullary canal of donors (50–80 years of age) undergoing hip replacement surgery for OA and were treated with or without Naproxen (100 μg/mL). Protein expression and phosphorylation were determined by immunoblotting using specific antibodies (COL X, p38 mitogen-activated protein kinase [p38], phosphorylated-p38, c-Jun N-terminal kinase [JNK], phosphorylated-JNK, extracellular signal-regulated kinase [ERK], and phosphorylated-ERK). Real-time reverse transcription polymerase chain reaction (RT-PCR) was performed to determine the expression of COL10A1 and Runt-related transcription factor 2 gene (Runx2). Our results show that Naproxen significantly stimulated COL X protein expression after 72 h of exposure both in normal and OA hMSCs. The basal phosphorylation of mitogen-activated protein kinases (MAPKs) (ERK, JNK, and p38) in OA hMSCs was significantly higher than in normal. Naproxen significantly increased the MAPK phosphorylation in normal and OA hMSCs. NSAID cellular effects include cyclooxygenase, 5-lipoxygenase, and p38 MAPK signaling pathways. To investigate the involvement of these pathways in the Naproxen-induced COL10A1 expression, we incubated normal and OA hMSCs with Naproxen with and without inhibitors of ERK (U0126), JNK (BI-78D3), p38 (SB203580), and 5-lipoxygenase (MK-886). Our results showed that increased basal COL10A1 expression in OA hMSCs was significantly suppressed in the presence of JNK and p38 inhibitors, whereas Naproxen-induced COL10A1 expression was suppressed by 5-lipoxygenase inhibitor. This study shows that Naproxen induces COL X both at transcriptional and translational levels in normal and OA hMSCs. Elevated basal COL10A1 expression in OA hMSCs is probably through the activation of MAPK pathway and Naproxen-induced COL10A1 expression is through the increased 5-lipoxygenase signaling. PMID:25091567

Effects of 17β-estradiol on the release of monocyte chemotactic protein-1 and MAPK activity in monocytes stimulated with peritoneal fluid from endometriosis patients.

PubMed

Lee, Dong-Hyung; Kim, Seung-Chul; Joo, Jong-Kil; Kim, Hwi-Gon; Na, Young-Jin; Kwak, Jong-Young; Lee, Kyu-Sup

2012-03-01

Hormones and inflammation have been implicated in the pathological process of endometriosis; therefore, we investigated the combined effects of 17β-estradiol (E2) and peritoneal fluid obtained from patients with endometriosis (ePF) or a control peritoneal fluid (cPF) obtained from patients without endometriosis on the release of monocyte chemotactic protein-1 (MCP-1) by monocytes and the role of signaling pathways. Monocytes were cultured with ePF and cPF in the presence of E2; the MCP-1 levels in the supernatants were then measured by ELISA. In addition, mitogen activated protein kinase (MAPK) activation was measured by Western blotting of phosphorylated proteins. E2 down-regulated MCP-1 release by lipopolysaccharide- or cPF-treated monocytes, but failed to suppress its release by ePF-treated monocytes. The release of MCP-1 by ePF- and cPF-treated monocytes was efficiently abrogated by p38 mitogen activated protein kinase (MAPK) inhibitors; however, the MCP-1 release by cPF-treated monocytes, but not by ePF-treated monocytes, was blocked by a MAPK kinase inhibitor. In addition, ePF and cPF induced the phosphorylation of extracellular stress regulated kinase (ERK)1/2, p38 MAPK and c-Jun N-terminal kinase (JNK). E2 decreased the phosphorylation of p38 MAPK, but not ERK1/2 in ePF-treated monocytes; however, E2 decreased the phosphorylation of p38 MAPK, ERK1/2 and JNK in cPF-treated monocytes. The ability of E2 to modulate MCP-1 production is impaired in ePF-treated monocytes, which may be related to regulation of MAPK activity. These findings suggest that the failure of E2 to suppress ePF-treated production of MCP-1 may be involved in the pathogenesis of endometriosis. © 2012 The Authors. Journal of Obstetrics and Gynaecology Research © 2012 Japan Society of Obstetrics and Gynecology.

Anti-influenza A virus activity of rhein through regulating oxidative stress, TLR4, Akt, MAPK, and NF-κB signal pathways

PubMed Central

Wang, Qian-Wen; Su, Yun; Sheng, Jiang-Tao; Gu, Li-Ming; Zhao, Ying; Chen, Xiao-Xuan; Chen, Cheng; Li, Wei-Zhong; Li, Kang-Sheng

2018-01-01

Rhein, an anthraquinone compound existing in many traditional herbal medicines, has anti-inflammatory, antioxidant, antitumor, antiviral, hepatoprotective, and nephroprotective activities, but its anti-influenza A virus (IAV) activity is ambiguous. In the present study, through plaque inhibition assay, time-of-addition assay, antioxidant assay, qRT-PCR, ELISA, and western blotting assays, we investigated the anti-IAV effect and mechanism of action of rhein in vitro and in vivo. The results showed that rhein could significantly inhibit IAV adsorption and replication, decrease IAV-induced oxidative stress, activations of TLR4, Akt, p38, JNK MAPK, and NF-κB pathways, and production of inflammatory cytokines and matrix metalloproteinases in vitro. Oxidant H2O2 and agonists of TLR4, Akt, p38/JNK and IKK/NF-κB could significantly antagonize the inhibitory effects of rhein on IAV-induced cytopathic effect (CPE) and IAV replication. Through an in vivo test in mice, we also found that rhein could significantly improve the survival rate, lung index, pulmonary cytokines, and pulmonary histopathological changes. Rhein also significantly decreased pulmonary viral load at a high dose. In conclusion, rhein can inhibit IAV adsorption and replication, and the mechanism of action to inhibit IAV replication may be due to its ability to suppress IAV-induced oxidative stress and activations of TLR4, Akt, p38, JNK MAPK, and NF-κB signal pathways. PMID:29385192

Anti-influenza A virus activity of rhein through regulating oxidative stress, TLR4, Akt, MAPK, and NF-κB signal pathways.

PubMed

Wang, Qian-Wen; Su, Yun; Sheng, Jiang-Tao; Gu, Li-Ming; Zhao, Ying; Chen, Xiao-Xuan; Chen, Cheng; Li, Wei-Zhong; Li, Kang-Sheng; Dai, Jian-Ping

2018-01-01

Rhein, an anthraquinone compound existing in many traditional herbal medicines, has anti-inflammatory, antioxidant, antitumor, antiviral, hepatoprotective, and nephroprotective activities, but its anti-influenza A virus (IAV) activity is ambiguous. In the present study, through plaque inhibition assay, time-of-addition assay, antioxidant assay, qRT-PCR, ELISA, and western blotting assays, we investigated the anti-IAV effect and mechanism of action of rhein in vitro and in vivo. The results showed that rhein could significantly inhibit IAV adsorption and replication, decrease IAV-induced oxidative stress, activations of TLR4, Akt, p38, JNK MAPK, and NF-κB pathways, and production of inflammatory cytokines and matrix metalloproteinases in vitro. Oxidant H2O2 and agonists of TLR4, Akt, p38/JNK and IKK/NF-κB could significantly antagonize the inhibitory effects of rhein on IAV-induced cytopathic effect (CPE) and IAV replication. Through an in vivo test in mice, we also found that rhein could significantly improve the survival rate, lung index, pulmonary cytokines, and pulmonary histopathological changes. Rhein also significantly decreased pulmonary viral load at a high dose. In conclusion, rhein can inhibit IAV adsorption and replication, and the mechanism of action to inhibit IAV replication may be due to its ability to suppress IAV-induced oxidative stress and activations of TLR4, Akt, p38, JNK MAPK, and NF-κB signal pathways.

Curcumin suppresses JNK pathway to attenuate BPA-induced insulin resistance in LO2 cells.

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; Zhong, Caiyun

2018-01-01

To examine whether curcumin has protective effect on insulin resistance induced by bisphenol A (BPA) in LO2 cells and whether this effect was mediated by inhibiting the inflammatory mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) pathways. LO2 cells were stimulated with BPA in the presence or absence of curcumin for 5 days. Glucose consumption, activation of insulin signaling, MAPKs and NF-κB pathways, levels of inflammatory cytokines and MDA production were analyzed. Curcumin prevented BPA-induced reduction of glucose consumption and suppression of insulin signaling pathway, indicating curcumin alleviated BPA-triggered insulin resistance in LO2 cells. mRNA and proteins levels of TNF-α and IL-6, as well as MDA level in LO2 cells treated with BPA were decreased by curcumin. Furthermore, curcumin downregulated the activation of p38, JNK, and NF-κB pathways upon stimulation with BPA. Inhibition of JNK pathway, but not p38 nor NF-κB pathway, improved glucose consumption and insulin signaling in BPA-treated LO2 cells. Curcumin inhibits BPA-induced insulin resistance by suppressing JNK pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Diagnostic Significance of p38 Isoforms (p38α, p38β, p38γ, p38δ) in Head and Neck Squamous Cell Carcinoma: Comparative Serum Level Evaluation and Design of Novel Peptide Inhibitor Targeting the Same.

PubMed

Sahu, Vishal; Nigam, Lokesh; Agnihotri, Vertica; Gupta, Abhishek; Shekhar, Shashank; Subbarao, Naidu; Bhaskar, Suman; Dey, Sharmistha

2018-05-09

The p38 mitogen-activated protein kinase (MAPKs) play a crucial role in the production of pro-inflammatory cytokines and over-expression of it increase cytokines which promote cancer. Among four isoforms, p38α has been well studied in head and neck squamous cell carcinoma (HNSCC) and other cancers as a therapeutic target.p38δ has recently emerged as a potential disease-specific drug target. Elevated serum p38α level in HNSCC was reported earlier from our lab. This study aims to estimate the levels of p38 MAPK-isoforms in the serum of HNSCC and design peptide inhibitor targeting the same. Levels of p38 MAPK isoforms in the serum of HNSCC and healthy controls were quantified by surface plasmon resonance technology. The peptide inhibitor for p38 MAPK was designed by molecular modeling using Grid-based Ligand Docking with Energetics tools and compared with known specific inhibitors. We have observed highly elevated levels of all four isoforms of p38 MAPK in serum of HNSCC patients compared to the control group. Further, serum p38α, p38β, and p38δ levels were down regulated after therapy in follow up patients, while p38γ showed no response to the therapy. Present study screened designed peptide WFYH as a specific inhibitor against p38δ. The specific inhibitor of p38δ was found to have no effect on p38α due to great structural difference at ATP binding pocket. In this study, first time estimated the levels of p38 MAPK isoforms in the serum of HNSCC. It can be concluded that p38 MAPK isoforms can be a diagnostic and prognostic marker for HNSCC and p38δ as a therapeutic target.

Dermal fibroblasts from long-lived Ames dwarf mice maintain their in vivo resistance to mitochondrial generated reactive oxygen species (ROS)

PubMed Central

Hsieh, Ching-Chyuan; Papaconstantinou, John

2009-01-01

Activation of p38 MAPK by ROS involves dissociation of an inactive, reduced thioredoxin-ASK1 complex [(SH)2Trx-ASK1]. Release of ASK1 activates its kinase activity thus stimulating the p38 MAPK pathway. The level of p38 MAPK activity is, therefore, regulated by the balance of free vs. bound ASK1. Longevity of Ames dwarf mice is attributed to their resistance to oxidative stress. The levels of (SH)2 Trx-ASK1 are more abundant in young and old dwarf mice compared to their age-matched controls suggesting that the levels of this complex may play a role in their resistance to oxidative stress. In these studies we demonstrate that dermal fibroblasts from these long-lived mice exhibit (a) higher levels of (SH)2Trx-ASK1 that correlate with their resistance to ROS generated by inhibitors of electron transport chain complexes CI (rotenone), CII (3-nitropropionic acid), CIII, (antimycin A), and H2O2-mediated activation of p38 MAPK, and (b) maintain their in vivo resistance to ROS generated by 3NPA. We propose that elevated levels of (SH)2Trx-ASK1 play a role in conferring resistance to mitochondrial generated oxidative stress and decreased endogenous ROS which are characteristics of longevity determination. PMID:20157567

Fluorophore Labeled Kinase Detects Ligands That Bind within the MAPK Insert of p38α Kinase

PubMed Central

Termathe, Martin; Grütter, Christian; Rabiller, Matthias; van Otterlo, Willem A. L.; Rauh, Daniel

2012-01-01

The vast majority of small molecules known to modulate kinase activity, target the highly conserved ATP-pocket. Consequently, such ligands are often less specific and in case of inhibitors, this leads to the inhibition of multiple kinases. Thus, selective modulation of kinase function remains a major hurdle. One of the next great challenges in kinase research is the identification of ligands which bind to less conserved sites and target the non-catalytic functions of protein kinases. However, approaches that allow for the unambiguous identification of molecules that bind to these less conserved sites are few in number. We have previously reported the use of fluorescent labels in kinases (FLiK) to develop direct kinase binding assays that exclusively detect ligands which stabilize inactive (DFG-out) kinase conformations. Here, we present the successful application of the FLiK approach to develop a high-throughput binding assay capable of directly monitoring ligand binding to a remote site within the MAPK insert of p38α mitogen-activated protein kinase (MAPK). Guided by the crystal structure of an initially identified hit molecule in complex with p38α, we developed a tight binding ligand which may serve as an ideal starting point for further investigations of the biological function of the MAPK insert in regulating the p38α signaling pathway. PMID:22768308

Role of human amnion-derived mesenchymal stem cells in promoting osteogenic differentiation by influencing p38 MAPK signaling in lipopolysaccharide -induced human bone marrow mesenchymal stem cells.

PubMed

Wang, Yuli; Wu, Hongxia; Shen, Ming; Ding, Siyang; Miao, Jing; Chen, Ning

2017-01-01

Periodontitis is a chronic inflammatory disease induced by bacterial pathogens, which not only affect connective tissue attachments but also cause alveolar bone loss. In this study, we investigated the anti-inflammatory effects of Human amnion-derived mesenchymal stem cells (HAMSCs) on human bone marrow mesenchymal stem cells (HBMSCs) under lipopolysaccharide (LPS)-induced inflammatory conditions. Proliferation levels were measured by flow cytometry and immunofluorescence staining of 5-ethynyl-2'-deoxyuridine (EdU). Osteoblastic differentiation and mineralization were investigated using chromogenic alkaline phosphatase activity (ALP) activity substrate assays, Alizarin red S staining, and RT-PCR analysis of HBMSCs osteogenic marker expression. Oxidative stress induced by LPS was investigated by assaying reactive oxygen species (ROS) level and superoxide dismutase (SOD) activity. Here, we demonstrated that HAMSCs increased the proliferation, osteoblastic differentiation, and SOD activity of LPS-induced HBMSCs, and down-regulated the ROS level. Moreover, our results suggested that the activation of p38 MAPK signal transduction pathway is essential for reversing the LPS-induced bone-destructive processes. SB203580, a selective inhibitor of p38 MAPK signaling, significantly suppressed the anti-inflammatory effects in HAMSCs. In conclusion, HAMSCs show a strong potential in treating inflammation-induced bone loss by influencing p38 MAPK signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

SIRT1 protects rat lung tissue against severe burn-induced remote ALI by attenuating the apoptosis of PMVECs via p38 MAPK signaling

PubMed Central

Bai, Xiaozhi; Fan, Lei; He, Ting; Jia, Wenbin; Yang, Longlong; Zhang, Jun; Liu, Yang; Shi, Jihong; Su, Linlin; Hu, Dahai

2015-01-01

Silent information regulator type-1 (SIRT1) has been reported to be involved in the cardiopulmonary protection. However, its role in the pathogenesis of burn-induced remote acute lung injury (ALI) is currently unknown. The present study aims to investigate the role of SIRT1 in burn-induced remote ALI and the involved signaling pathway. We observed that SIRT1 expression in rat lung tissue after burn injury appeared an increasing trend after a short period of suppression. The upregulation of SIRT1 stimulated by resveratrol exhibited remission of histopathologic changes, reduction of cell apoptosis, and downregulation of pro-inflammatory cytokines in rat pulmonary tissues suffering from severe burn. We next used primary pulmonary microvascular endothelial cells (PMVECs) challenged by burn serum (BS) to simulate in vivo rat lung tissue after burn injury, and found that BS significantly suppressed SIRT1 expression, increased cell apoptosis, and activated p38 MAPK signaling. The use of resveratrol reversed these effects, while knockdown of SIRT1 by shRNA further augmented BS-induced increase of cell apoptosis and activation of p38 MAPK. Taken together, these results indicate that SIRT1 might protect lung tissue against burn-induced remote ALI by attenuating PMVEC apoptosis via p38 MAPK signaling, suggesting its potential therapeutic effects on the treatment of ALI. PMID:25992481

Stress-induced interaction between p38 MAPK and HSP70

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, Xiaowei, E-mail: gongxw@fimmu.com; Luo, Tingting; Deng, Peng

2012-08-24

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

Slack sodium-activated potassium channel membrane expression requires p38 mitogen-activated protein kinase phosphorylation.

PubMed

Gururaj, Sushmitha; Fleites, John; Bhattacharjee, Arin

2016-04-01

p38 MAPK has long been understood as an inducible kinase under conditions of cellular stress, but there is now increasing evidence to support its role in the regulation of neuronal function. Several phosphorylation targets have been identified, an appreciable number of which are ion channels, implicating the possible involvement of p38 MAPK in neuronal excitability. The KNa channel Slack is an important protein to be studied as it is highly and ubiquitously expressed in DRG neurons and is important in the maintenance of their firing accommodation. We sought to examine if the Slack channel could be a substrate of p38 MAPK activity. First, we found that the Slack C-terminus contains two putative p38 MAPK phosphorylation sites that are highly conserved across species. Second, we show via electrophysiology experiments that KNa currents and further, Slack currents, are subject to tonic modulation by p38 MAPK. Third, biochemical approaches revealed that Slack channel regulation by p38 MAPK occurs through direct phosphorylation at the two putative sites of interaction, and mutating both sites prevented surface expression of Slack channels. Based on these results, we conclude that p38 MAPK is an obligate regulator of Slack channel function via the trafficking of channels into the membrane. The present study identifies Slack KNa channels as p38 MAPK substrates. Copyright © 2015 Elsevier Ltd. All rights reserved.

Slack Sodium-activated Potassium Channel Membrane Expression Requires p38 Mitogen-Activated Protein Kinase Phosphorylation

PubMed Central

Gururaj, Sushmitha; Fleites, John; Bhattacharjee, Arin

2016-01-01

p38 MAPK has long been understood as an inducible kinase under conditions of cellular stress, but there is now increasing evidence to support its role in the regulation of neuronal function. Several phosphorylation targets have been identified, an appreciable number of which are ion channels, implicating the possible involvement of p38 MAPK in neuronal excitability. The KNa channel Slack is an important protein to be studied as it is highly and ubiquitously expressed in DRG neurons and is important in the maintenance of their firing accommodation. We sought to examine if the Slack channel could be a substrate of p38 MAPK activity. First, we found that the Slack C-terminus contains two putative p38 MAPK phosphorylation sites that are highly conserved across species. Second, we show via electrophysiology experiments that KNa currents and further, Slack currents, are subject to tonic modulation by p38 MAPK. Third, biochemical approaches revealed that Slack channel regulation by p38 MAPK occurs through direct phosphorylation at the two putative sites of interaction, and mutating both sites prevented surface expression of Slack channels. Based on these results, we conclude that p38 MAPK is an obligate regulator of Slack channel function via the trafficking of channels into the membrane. The present study identifies Slack KNa channels as p38 MAPK substrates. PMID:26721627

TGF-β and BMP Signaling in Osteoblast Differentiation and Bone Formation

PubMed Central

Chen, Guiqian; Deng, Chuxia; Li, Yi-Ping

2012-01-01

Transforming growth factor-beta (TGF-β)/bone morphogenic protein (BMP) signaling is involved in a vast majority of cellular processes and is fundamentally important throughout life. TGF-β/BMPs have widely recognized roles in bone formation during mammalian development and exhibit versatile regulatory functions in the body. Signaling transduction by TGF-β/BMPs is specifically through both canonical Smad-dependent pathways (TGF-β/BMP ligands, receptors and Smads) and non-canonical Smad-independent signaling pathway (e.g. p38 mitogen-activated protein kinase pathway, MAPK). Following TGF-β/BMP induction, both the Smad and p38 MAPK pathways converge at the Runx2 gene to control mesenchymal precursor cell differentiation. The coordinated activity of Runx2 and TGF-β/BMP-activated Smads is critical for formation of the skeleton. Recent advances in molecular and genetic studies using gene targeting in mice enable a better understanding of TGF-β/BMP signaling in bone and in the signaling networks underlying osteoblast differentiation and bone formation. This review summarizes the recent advances in our understanding of TGF-β/BMP signaling in bone from studies of genetic mouse models and human diseases caused by the disruption of TGF-β/BMP signaling. This review also highlights the different modes of cross-talk between TGF-β/BMP signaling and the signaling pathways of MAPK, Wnt, Hedgehog, Notch, and FGF in osteoblast differentiation and bone formation. PMID:22298955

Schisandrin B elicits a glutathione antioxidant response and protects against apoptosis via the redox-sensitive ERK/Nrf2 pathway in H9c2 cells.

PubMed

Chiu, Po Yee; Chen, Na; Leong, Po Kuan; Leung, Hoi Yan; Ko, Kam Ming

2011-04-01

This study investigated the signal transduction pathway involved in the cytoprotective action of (-)schisandrin B [(-)Sch B, a stereoisomer of Sch B]. Using H9c2 cells, the authors examined the effects of (-)Sch B on MAPK and Nrf2 activation, as well as the subsequent eliciting of glutathione response and protection against apoptosis. Pharmacological tools, such as cytochrome P-450 (CYP) inhibitor, antioxidant, MAPK inhibitor, and Nrf2 RNAi, were used to delineate the signaling pathway. (-)Sch B caused a time-dependent activation of MAPK in H9c2 cells, with the degree of ERK activation being much larger than that of p38 or JNK. The MAPK activation was followed by an increase in the level of nuclear Nrf2, an indirect measure of Nrf2 activation, and the eliciting of a glutathione antioxidant response. The activation of MAPK and Nrf2 seemed to involve oxidants generated from a CYP-catalyzed reaction with (-)Sch B. Both ERK inhibition by U0126 and Nrf2 suppression by Nrf2 RNAi transfection largely abolished the cytoprotection against hypoxia/reoxygenation-induced apoptosis in (-)Sch B-pretreated cells. (-)Sch B pretreatment potentiated the reoxygenation-induced ERK activation, whereas both p38 and JNK activations were suppressed. Under the condition of ERK inhibition, Sch B treatment did not protect against ischemia/reperfusion injury in an ex vivo rat heart model. The results indicate that (-)Sch B triggers a redox-sensitive ERK/Nrf2 signaling, which then elicits a cellular glutathione antioxidant response and protects against hypoxia/reoxygenation-induced apoptosis in H9c2 cells. The ERK-mediated signaling is also likely involved in the cardioprotection afforded by Sch B in vivo.

N-n-butyl Haloperidol Iodide Protects against Hypoxia/Reoxygenation Injury in Cardiac Microvascular Endothelial Cells by Regulating the ROS/MAPK/Egr-1 Pathway

PubMed Central

Lu, Shishi; Zhang, Yanmei; Zhong, Shuping; Gao, Fenfei; Chen, Yicun; Li, Weiqiu; Zheng, Fuchun; Shi, Ganggang

2017-01-01

Endothelium dysfunction induced by reactive oxygen species (ROS) is an important initial event at the onset of myocardial ischemia/reperfusion in which the Egr-1 transcription factor often serves as a master switch for various damage pathways following reperfusion injury. We hypothesized that an intracellular ROS/MAPK/Egr-1 signaling pathway is activated in cardiac microvascular endothelial cells (CMECs) following hypoxia/reoxygenation (H/R). ROS generation, by either H/R or the ROS donor xanthine oxidase-hypoxanthine (XO/HX) activated all three MAPKs (ERK1/2, JNK, p38), and induced Egr-1 expression and Egr-1 DNA-binding activity in CMECs, whereas ROS scavengers (EDA and NAC) had the opposite effect following H/R. Inhibitors of all three MAPKs individually inhibited induction of Egr-1 expression by H/R in CMECs. Moreover, N-n-butyl haloperidol (F2), previously shown to protect cardiomyocytes subjected to I/R, dose-dependently downregulated H/R-induced ROS generation, MAPK activation, and Egr-1 expression and activity in CMECs, whereas XO/HX and MAPK activators (EGF, anisomycin) antagonized the effects of F2. Inhibition of the ROS/MAPK/Egr-1 signaling pathway, by either F2, NAC, or inhibition of MAPK, increased CMEC viability and the GSH/GSSG ratio, and decreased Egr-1 nuclear translocation. These results show that the ROS/MAPK/Egr-1 signaling pathway mediates H/R injury in CMECs, and F2 blocks this pathway to protect against H/R injury and further alleviate myocardial I/R injury. PMID:28111550

Effects of chromium picolinate on glucose uptake in insulin-resistant 3T3-L1 adipocytes involve activation of p38 MAPK.

PubMed

Wang, Yi-qun; Yao, Ming-hui

2009-12-01

Chromium picolinate (CrPic) has been discovered as a supplemental or alternative medication for type 2 diabetes, but its mechanism of action is not well understood. The purpose of this study was to explore the possible anti-diabetic mechanisms of CrPic in insulin-resistant 3T3-L1 adipocytes; the insulin resistance was induced by treatment with high glucose and insulin for 24 h. The effects of CrPic on glucose metabolism and the glucose uptake-inducing activity of CrPic were investigated. Meanwhile, the effects of CrPic on glucose transporter 4 (GLUT4) translocation were visualized by immonofluorescence microscopy. In addition, its effects on insulin signaling pathways and mitogen-activated protein kinase (MAPK) signaling cascades were assessed by immunoblotting analysis and real-time PCR. The results showed that CrPic induced glucose metabolism and uptake, as well as GLUT4 translocation to plasma membrane (PM) in both control and insulin-resistant 3T3-L1 adipocytes without any changes in insulin receptor beta (IR-beta), protein kinase B (AKt), c-Cbl, extracellular signal-regulated kinase (ERK), c-Jun phosphorylation and c-Cbl-associated protein (CAP) mRNA levels. Interestingly, CrPic was able to increase the basal and insulin-stimulated levels of p38 MAPK activation in the control and insulin-resistant cells. Pretreatment with the specific p38 MAPK inhibitor SB203580 partially inhibited the CrPic-induced glucose transport, but CrPic-activated translocation of GLUT4 was not inhibited by SB203580. This study provides an experimental evidence of the effects of CrPic on glucose uptake through the activation of p38 MAPK and it is independent of the effect on GLUT4 translocation. The findings also suggest exciting new insights into the role of p38 MAPK in glucose uptake and GLUT4 translocation.

The Protective Effect of Rhizoma Dioscoreae Extract against Alveolar Bone Loss in Ovariectomized Rats via Regulating Wnt and p38 MAPK Signaling

PubMed Central

Zhang, Zhiguo; Xiang, Lihua; Bai, Dong; Wang, Wenlai; Li, Yan; Pan, Jinghua; Liu, Hong; Wang, Shaojun; Xiao, Gary Guishan; Ju, Dahong

2014-01-01

Aim: The aim of this study was to evaluate the osteoprotective effect of aqueous Rhizoma Dioscoreae extract (RDE) on the alveolar bone of rats with ovariectomy-induced bone loss. Methods: Female Wistar rats were subjected to either ovariectomy or a sham operation (SHAM). The ovariectomized (OVX) rats were treated with vehicle (OVX) or RDE by oral gavage or with 17β-estradiol (E2) subcutaneously. After treatments, the bone mineral density (BMD), the three-dimensional bone architecture of the alveolar bone and the plasma biomarkers of bone turnover were analyzed to assess bone metabolism, and the histomorphometry of the alveolar bone was observed. Microarrays were used to evaluate gene expression profiles in alveolar bone from RDE-treated and OVX rats. The differential expression of genes was further analyzed using Ingenuity Pathway Analysis (IPA). The key findings were verified using real-time quantitative RT-PCR (qRT-PCR). Results: Our results showed that RDE inhibited alveolar bone loss in OVX rats. Compared to the OVX rats, the RDE-treated rats showed upregulated expression levels of 207 genes and downregulated expression levels of 176 genes in the alveolar bone. The IPA showed that several genes had the potential to code for proteins that were involved in the Wnt/β-catenin signaling pathway (Wnt7a, Fzd2, Tcf3, Spp1, Frzb, Sfrp2 and Sfrp4) and the p38 MAPK signaling pathway (Il1rn and Mapk14). Conclusion: These experiments revealed that RDE could inhibit ovariectomy-induced alveolar bone loss in rats. The mechanism of this anti-osteopenic effect in alveolar bone may be involved in the reduced abnormal bone remodeling, which is associated with the modulation of the Wnt/β-catenin and the p38 MAPK signaling pathways via gene regulation. PMID:25514564

Betalactam antibiotics affect human dendritic cells maturation through MAPK/NF-kB systems. Role in allergic reactions to drugs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, Soledad; Department of Medical Biochemistry, Molecular Biology and Immunology, The University of Seville Medical School, Seville; Gomez, Enrique

The mechanisms leading to drug allergy in predisposed patients, especially those related to T-cell-mediated drug hypersensitivity, are not well understood. A key event in allergic reactions to drugs is the maturation process undergone by dendritic cells (DCs). Although amoxicillin (AX) has been reported to interact and maturate DCs from patients with AX-induced delayed-type hypersensitivity, the cell signaling pathways related to AX-mediated DC maturation have not been elucidated. We sought to determine the role of the MAPK and NF-κΒ pathways on AX-induced DC maturation and functional status. For that purpose, in monocyte-derived-DCs from AX-delayed allergic patients and tolerant subjects, we analyzedmore » the activation pattern of p38MAPK, JNK, and ERK signaling and the NF-κB, maturation markers as well as endocytosis and allostimulatory capacities driven by AX-stimulated-DCs. Our data reveal that AX induces an increase in the phosphorylation levels of the three MAPKsand activated NF-κB in DCs from allergic patients. Moreover, the inhibition of these pathways prevents the up-regulation of surface molecules induced by AX. Additionally, we observed that the allostimulatory capacity and the endocytosis down-regulation in AX-stimulated-DCs from allergic patients depend on JNK and NF-κB activities. Taken together, our data shed light for the first time on the main signaling pathways involved in DC maturation from AX-delayed allergic patient. - Highlights: • The cell signaling pathways related to drug-mediated DC maturation were tested. • Amoxicillin induces activation of MAPK and NF-κB in DCs from allergic patients. • The inhibition of these pathways prevents the up-regulation of DC surface molecules. • Their allostimulatory and endocytosis capacities depend on JNK and NF-κB activities. • The low involvement of p38-MAPK could be the cause of an incomplete DC maturation.« less

Sika pilose antler type I collagen promotes BMSC differentiation via the ERK1/2 and p38-MAPK signal pathways.

PubMed

Wang, Yanshuang; Luo, Su; Zhang, Dafang; Qu, Xiaobo; Tan, Yinfeng

2017-12-01

Sika pilose antler type I collagen (SPC-I) have been reported to promote bone marrow mesenchymal stem cell (BMSC) proliferation and differentiation. However, the underlying mechanism is still unclear. This study investigates the molecular mechanisms of SPC-I on the BMSC proliferation and differentiation of osteoblast (OB) in vitro. The primary rat BMSC was cultured and exposed to SPC-I at different concentrations (2.5, 5.0 and 10.0 mg/mL) for 20 days. The effect of SPC-I on the differentiation of BMSCs was evaluated through detecting the activity of alkaline phosphatase (ALP), ALP staining, collagen I (Col-I) content, and calcified nodules. The markers of osteoblastic differentiation were evaluated using RT-PCR and Western-blot analysis. SPC-I treatment (2.5 mg/mL) significantly increased the proliferation of BMSCs (p < 0.01), whereas, SPC-I (5.0 and 10.0 mg/mL) significantly inhibited the proliferation of BMSCs (p < 0.01). SPC-I (2.5 mg/mL) significantly increased ALP activity and Col-I content (p < 0.01), and increased positive cells in ALP staining and the formation of calcified nodules. Additionally, the gene expression of ALP, Col-I, Osteocalcin (OC), Runx2, Osterix (Osx), ERK1/2, BMP2 and p38-MAPK, along with the protein expression of ERK1/2, p-ERK1/2, p-p38 MAPK were markedly increased in the SPC-I (5.0 mg/mL) treatment group (p < 0.01) compared to the control group. SPC-I can induce BMSC differentiation into OBs and enhance the function of osteogenesis through ERK1/2 and p38-MAPK signal transduction pathways and regulating the gene expression of osteogenesis-specific transcription factors.

IL-17A acts via p38 MAPK to increase stability of TNF-alpha-induced IL-8 mRNA in human ASM.

PubMed

Henness, Sheridan; van Thoor, Eveline; Ge, Qi; Armour, Carol L; Hughes, J Margaret; Ammit, Alaina J

2006-06-01

Human airway smooth muscle (ASM) plays an immunomodulatory role in asthma. Recently, IL-17A has become of increasing interest in asthma, being found at elevated levels in asthmatic airways and emerging as playing an important role in airway neutrophilia. IL-17A predominantly exerts its neutrophil orchestrating role indirectly via the induction of cytokines by resident airway structural cells. Here, we perform an in vitro study to show that although IL-17A did not induce secretion of the CXC chemokine IL-8 from ASM cells, IL-17A significantly potentiates TNF-alpha-induced IL-8 protein secretion and gene expression in a concentration- and time-dependent manner (P < 0.05). Levels of IL-8 protein produced after 24 h of incubation with TNF-alpha were enhanced 2.7-fold in the presence of IL-17A, and conditioned media significantly enhanced neutrophil chemotaxis in vitro. As IL-17A had no effect on the activity of NF-kappaB, a key transcriptional regulator of IL-8 gene expression, we then examined whether IL-17A acts at the posttranscriptional level. We found that IL-17A significantly augmented TNF-alpha-induced IL-8 mRNA stability. Interestingly, this enhanced stability occurred via a p38 MAPK-dependent pathway. The decay of IL-8 mRNA transcripts proceeded at a significantly faster rate when cells were pretreated with the p38 MAPK inhibitor SB-203580 (-0.05763 +/- 0.01964, t(1/2) = 12.0 h), compared with vehicle (-0.01030 +/- 0.007963, t(1/2) = 67.3 h) [results are expressed as decay constant (means +/- SE) and half-life (t(1/2) in h): P < 0.05]. Collectively, these results demonstrate that IL-17A amplifies the synthetic function of ASM cells, acting via a p38 MAPK-dependent posttranscriptional pathway to augment TNF-alpha-induced secretion of the potent neutrophil chemoattractant IL-8 from ASM cells.

A Chemically Modified Curcumin (CMC 2.24) Inhibits Nuclear Factor κB Activation and Inflammatory Bone Loss in Murine Models of LPS-Induced Experimental Periodontitis and Diabetes-Associated Natural Periodontitis.

PubMed

Elburki, Muna S; Rossa, Carlos; Guimarães-Stabili, Morgana R; Lee, Hsi-Ming; Curylofo-Zotti, Fabiana A; Johnson, Francis; Golub, Lorne M

2017-08-01

The purpose of this study was to assess the effect of a novel chemically modified curcumin (CMC 2.24) on NF-κB and MAPK signaling and inflammatory cytokine production in two experimental models of periodontal disease in rats. Experimental model I: Periodontitis was induced by repeated injections of LPS into the gingiva (3×/week, 3 weeks); control rats received vehicle injections. CMC 2.24, or the vehicle, was administered by daily oral gavage for 4 weeks. Experimental model II: Diabetes was induced in adult male rats by streptozotocin injection; periodontal breakdown then results as a complication of uncontrolled hyperglycemia. Non-diabetic rats served as controls. CMC 2.24, or the vehicle, was administered by oral gavage daily for 3 weeks to the diabetics. Hemimaxillae and gingival tissues were harvested, and bone loss was assessed radiographically. Gingival tissues were pooled according to the experimental conditions and processed for the analysis of matrix metalloproteinases (MMPs) and bone-resorptive cytokines. Activation of p38 MAPK and NF-κB signaling pathways was assessed by western blot. Both LPS and diabetes induced an inflammatory process in the gingival tissues associated with excessive alveolar bone resorption and increased activation of p65 (NF-κB) and p38 MAPK. In both models, the administration of CMC 2.24 produced a marked reduction of inflammatory cytokines and MMPs in the gingival tissues, decreased bone loss, and decreased activation of p65 (NF-κB) and p38 MAPK. Inhibition of these cell signaling pathways by this novel tri-ketonic curcuminoid (natural curcumin is di-ketonic) may play a role in its therapeutic efficacy in locally and systemically associated periodontitis.

The calcineurin pathway links hyperpolarization (Kir2.1)-induced Ca2+ signals to human myoblast differentiation and fusion.

PubMed

Konig, Stéphane; Béguet, Anne; Bader, Charles R; Bernheim, Laurent

2006-08-01

In human myoblasts triggered to differentiate, a hyperpolarization, resulting from K+ channel (Kir2.1) activation, allows the generation of an intracellular Ca2+ signal. This signal induces an increase in expression/activity of two key transcription factors of the differentiation process, myogenin and MEF2. Blocking hyperpolarization inhibits myoblast differentiation. The link between hyperpolarization-induced Ca2+ signals and the four main regulatory pathways involved in myoblast differentiation was the object of this study. Of the calcineurin, p38-MAPK, PI3K and CaMK pathways, only the calcineurin pathway was inhibited when Kir2.1-linked hyperpolarization was blocked. The CaMK pathway, although Ca2+ dependent, is unaffected by changes in membrane potential or block of Kir2.1 channels. Concerning the p38-MAPK and PI3K pathways, their activity is present already in proliferating myoblasts and they are unaffected by hyperpolarization or Kir2.1 channel block. We conclude that the Kir2.1-induced hyperpolarization triggers human myoblast differentiation via the activation of the calcineurin pathway, which, in turn, induces expression/activity of myogenin and MEF2.

[MAPK signaling pathways involved in aluminum-induced apoptosis and necroptosis in SH-SY5Y cells].

PubMed

Jia, Xiaofang; Zhang, Qinli; Niu, Qiao

2014-11-01

To explore the role of MAPK signaling pathway in apoptosis and necroptosis induced by aluminum in SH-SY5Y cells. To imitate neural cell death induced by aluminium, AlCl3 x 6H2O (4 mmol/L) was used to treat SH-SY5Y cells. Necrostatin-1 (Nec-1,60 μmol/L), the specific inhibitor for necroptosis, and zVAD-fmk (20 μmol/L), the specific inhibitor for apoptosis, were added into cultures for inhibiting the occurrence of necroptosis and apoptosis. CCK-8 was performed to measure cell viability, flow cytometry was used to test the difference of apoptosis rate and necrosis rate between groups, and western-blot was used to detect the change of MAPK protein. Compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group, cell viabiligy of Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group decreaced (P < 0.05). Compared with Al(3+) exposed group, cell viability of Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group increased (P < 0.05). Necrotic rate and apoptotic rate in Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group obviously increased compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group (P < 0.05). Compared with Al(3+) exposed group, necrotic and apaptotic rate of Al(3+) plus zVAD-fmk group and Al(3+) plus Nec-1 group were statistically significant decreased (P < 0.05). Compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group, expression of p-p38 in Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group increased obviously (P < 0.05), and expression of p-ERK decreased significantly (P < 0.05). Compared with Al(3+) exposed group, expression of p-p38 decreased (P < 0.05), but p-ERK increased in Al(3+) plus Nec-1 group (P < 0.05). The ERK and p38 MAPK signaling pathways are involved in aluminum-induced necroptosis in SH-SY5Y cells, but only ERK signaling pathway is involved in aluminum-induced apoptosis, and JNK signaling pathway is not involved in aluminum-induced cell death.

Cigarette smoke-induced cell cycle arrest in spermatocytes [GC-2spd(ts)] is mediated through crosstalk between Ahr-Nrf2 pathway and MAPK signaling.

PubMed

Esakky, Prabagaran; Hansen, Deborah A; Drury, Andrea M; Moley, Kelle H

2015-02-01

Our earlier studies have demonstrated that the cigarette smoke in the form of cigarette smoke condensate (CSC) causes growth arrest of a mouse spermatocyte cell line [GC-2spd(ts)] through activation of the AHR-NRF2 pathway. The present study demonstrates the CSC-activated p38 and ERK MAPK signaling in GC-2spd(ts) via arylhydrocarbon receptor (AHR). Pharmacological inhibition by using AHR-antagonist, or p38 MAPK and ERK (MEK1) inhibitors significantly abrogates CSC-induced growth arrest by AHR and MAPK inactivation. QRT-PCR, western blot, and immunofluorescence of Ahr-target of Nrf2, and stress-inducible growth suppressive Atf3 and E2f4 following treatments indicate a crosstalk among these pathways. Regulation of Atf3 by Nrf2 and Ahr through RNA interference suggests the existence of a cross-regulatory loop between the targets. CSC induction of E2f4 via Atf3 and its regulation by pharmacological inhibitors reveal a possible regulatory mechanism of growth inhibitory CSC. SiRNA silencing of Ahr, Nrf2, Atf3, and E2f4 genes and downregulation of cyclins by CSC corroborate the growth inhibitory effect of cigarette smoke. Thus, the data obtained suggest that the CSC-mediated MAPKs and AHR-NRF2 crosstalks lay the molecular basis for the growth arrest and cell death of spermatocytes. © The Author (2014). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

p38 inhibitor inhibits the apoptosis of cowanin-treated human colorectal adenocarcinoma cells.

PubMed

Chowchaikong, Nittiya; Nilwarangkoon, Sirinun; Laphookhieo, Surat; Tanunyutthawongse, Chantra; Watanapokasin, Ramida

2018-06-01

Colorectal cancer, which is the third most common type of cancer diagnosed in both men and women, is the leading cause of cancer-related deaths worldwide. Cowanin is a pure compound extracted from Garcinia cowa Roxb., a tree species present in Thailand, Malaysia and Myanmar. The crude extract has been demonstrated to have antitumor activity, inflammation induction, antibacterial activity, anti-inflammatory activity and antimalarial activity. In the present study, the effects of cowanin on apoptosis induction and on the apoptosis-related and mitogen-activated protein kinase (MAPK) pathways were investigated in the LoVo human colorectal cancer cell line. The cytotoxicity of cowanin in LoVo cells was determined by MTT assay. Hoechst 33342 and JC‑1 staining were used to determine nuclear morphological changes and mitochondrial membrane potential, respectively. The expression levels of BCL2 apoptosis regulator (Bcl‑2) family, MAPK and AKT serine/threonine kinase 1 (Akt) pathway proteins following cowanin treatment were determined by western blot analysis. The results demonstrated that cowanin inhibited cell proliferation and induced cell death via the apoptosis pathway. Cowanin treatment increased BCL2 associated X (Bax) and decreased Bcl‑2 expression. In addition, cowanin activated caspase‑9, -7 and poly-ADP-ribose-polymerase expression. Furthermore, cowanin decreased the levels of phosphorylated extracellular signal-regulated kinase (p‑ERK), p‑Akt, p‑3‑phosphoinositide‑dependent protein kinase‑1, while it increased p‑p38 expression, thus resulting in the induction of apoptosis. In conclusion, cowanin inhibited cell proliferation and induced apoptosis of LoVo cells via the MAPK and Akt signaling pathways. Notably, inhibition of p38 by using a p38 inhibitor (SB203580) prevented the cowanin-induced apoptosis in LoVo cells. These results suggested that cowanin may be a potential candidate for the treatment of colorectal cancer and provided important information on the molecular mechanisms underlying its antitumor activity.

Shigella flexneri type III secreted effector OspF reveals new crosstalks of proinflammatory signaling pathways during bacterial infection.

PubMed

Reiterer, Veronika; Grossniklaus, Lars; Tschon, Therese; Kasper, Christoph Alexander; Sorg, Isabel; Arrieumerlou, Cécile

2011-07-01

Shigella flexneri type III secreted effector OspF harbors a phosphothreonine lyase activity that irreversibly dephosphorylates MAP kinases (MAPKs) p38 and ERK in infected epithelial cells and thereby, dampens innate immunity. Whereas this activity has been well characterized, the impact of OspF on other host signaling pathways that control inflammation was unknown. Here we report that OspF potentiates the activation of the MAPK JNK and the transcription factor NF-κB during S. flexneri infection. This unexpected effect of OspF was dependent on the phosphothreonine lyase activity of OspF on p38, and resulted from the disruption of a negative feedback loop regulation between p38 and TGF-beta activated kinase 1 (TAK1), mediated via the phosphorylation of TAK1-binding protein 1. Interestingly, potentiated JNK activation was not associated with enhanced c-Jun signaling as OspF also inhibits c-Jun expression at the transcriptional level. Altogether, our data reveal the impact of OspF on the activation of NF-κB, JNK and c-Jun, and demonstrate the existence of a negative feedback loop regulation between p38 and TAK1 during S. flexneri infection. Furthermore, this study validates the use of bacterial effectors as molecular tools to identify the crosstalks that connect important host signaling pathways induced upon bacterial infection. Copyright © 2011 Elsevier Inc. All rights reserved.

Sulforaphane, a natural constituent of broccoli, prevents cell death and inflammation in nephropathy.

PubMed

Guerrero-Beltrán, Carlos Enrique; Mukhopadhyay, Partha; Horváth, Béla; Rajesh, Mohanraj; Tapia, Edilia; García-Torres, Itzhel; Pedraza-Chaverri, José; Pacher, Pál

2012-05-01

Cisplatin (cis-diamminedichloroplatinum II, CIS) is a potent and widely used chemotherapeutic agent to treat various malignancies, but its therapeutic use is limited because of dose-dependent nephrotoxicity. Cell death and inflammation play a key role in the development and progression of CIS-induced nephropathy. Sulforaphane (SFN), a natural constituent of cruciferous vegetables such as broccoli, Brussels sprouts, etc., has been shown to exert various protective effects in models of tissue injury and cancer. In this study, we have investigated the role of prosurvival, cell death and inflammatory signaling pathways using a rodent model of CIS-induced nephropathy, and explored the effects of SFN on these processes. Cisplatin triggered marked activation of stress signaling pathways [p53, Jun N-terminal kinase (JNK), and p38-α mitogen-activated protein kinase (MAPK)] and promoted cell death in the kidneys (increased DNA fragmentation, caspases-3/7 activity, terminal deoxynucleotidyl transferase-mediated uridine triphosphate nick-end labeling), associated with attenuation of various prosurvival signaling pathways [e.g., extracellular signal-regulated kinase (ERK) and p38-β MAPK]. Cisplatin also markedly enhanced inflammation in the kidneys [promoted NF-κB activation, increased expression of adhesion molecules ICAM and VCAM, enhanced tumor necrosis factor-α (TNF-α) levels and inflammatory cell infiltration]. These effects were significantly attenuated by pretreatment of rodents with SFN. Thus, the cisplatin-induced nephropathy is associated with activation of various cell death and proinflammatory pathways (p53, JNK, p38-α, TNF-α and NF-κB) and impairments of key prosurvival signaling mechanisms (ERK and p38-β). SFN is able to prevent the CIS-induced renal injury by modulating these pathways, providing a novel approach for preventing this devastating complication of chemotherapy. Published by Elsevier Inc.

Sulforaphane, a natural constituent of broccoli, prevents cell death and inflammation in nephropathy

PubMed Central

Guerrero-Beltrán, Carlos Enrique; Mukhopadhyay, Partha; Horváth, Béla; Rajesh, Mohanraj; Tapia, Edilia; García-Torres, Itzhel; Pedraza-Chaverri, José; Pacher, Pál

2011-01-01

Cisplatin (cis-diamminedichloroplatinum II, CIS) is a potent and widely used chemotherapeutic agent to treat various malignancies, but its therapeutic use is limited because of the dose-dependent nephrotoxicity. Cell death and inflammation play key role in the development and progression of CIS-induced nephropathy. Sulforaphane (SFN), a natural constituent of cruciferous vegetables such as broccoli, Brussels sprouts, etc., has been shown to exert various protective effects in models of tissue injury and cancer. In this study, we have investigated the role of pro-survival, cell death and inflammatory signaling pathways using a rodent model of CIS-induced nephropathy, and explored the effects of SFN on these processes. Cisplatin triggered marked activation of stress signaling pathways (p53, Jun N-terminal kinase (JNK), and p38-α MAPK) and promoted cell death in the kidneys (increased DNA fragmentation, caspases-3/7 activity, TUNEL), associated with attenuation of various pro-survival signaling pathways (e.g. extracellular signal-regulated kinase (ERK) and p38-β MAPK). Cisplatin also markedly enhanced inflammation in the kidneys (promoted NF-κB activation, increased expression of adhesion molecules ICAM and VCAM, enhanced tumor necrosis factor-alpha (TNF-α) levels, and inflammatory cell infiltration). These effects were significantly attenuated by pre-treatment of rodents with SFN. Cisplatin-induced nephropathy is associated with activation of various cell death and pro-inflammatory pathways (p53, JNK, p38-α, TNF-α, and NF-κB) and impairments of key pro-survival signaling mechanisms (ERK and p38-β). SFN is able to prevent the CIS-induced renal injury by modulating these pathways, providing a novel approach for preventing this devastating complication of the chemotherapy. PMID:21684138

Phyllanthus Suppresses Prostate Cancer Cell, PC-3, Proliferation and Induces Apoptosis through Multiple Signalling Pathways (MAPKs, PI3K/Akt, NFκB, and Hypoxia).

PubMed

Tang, Yin-Quan; Jaganath, Indubala; Manikam, Rishya; Sekaran, Shamala Devi

2013-01-01

Phyllanthus is a traditional medicinal plant that has been found to have antihepatitis, antibacterial, and anticancer properties. The present studies were to investigate the in vitro molecular mechanisms of anticancer effects of Phyllanthus (P. amarus, P. niruri, P. urinaria, and P. watsonii) plant extracts in human prostate adenocarcinoma. The cancer ten-pathway reporter array was performed and revealed that the expression of six pathway reporters were significantly decreased (Wnt, NFκB, Myc/Max, hypoxia, MAPK/ERK, and MAPK/JNK) in PC-3 cells after treatment with Phyllanthus extracts. Western blot was conducted and identified several signalling molecules that were affected in the signalling pathways including pan-Ras, c-Raf, RSK, Elk1, c-Jun, JNK1/2, p38 MAPK, c-myc, DSH, β-catenin, Akt, HIF-1α, GSK3β, NFκB p50 and p52, Bcl-2, Bax, and VEGF, in treated PC-3 cells. A proteomics-based approach, 2D gel electrophoresis, was performed, and mass spectrometry (MS/MS) results revealed that there were 72 differentially expressed proteins identified in treated PC-3 cells and were involved in tumour cell adhesion, apoptosis, glycogenesis and glycolysis, metastasis, angiogenesis, and protein synthesis and energy metabolism. Overall, these findings suggest that Phyllanthus can interfere with multiple signalling cascades involved in tumorigenesis and be used as a potential therapeutic candidate for treatment of cancer.

Effects of Cyclic Mechanical Stretch on the Proliferation of L6 Myoblasts and Its Mechanisms: PI3K/Akt and MAPK Signal Pathways Regulated by IGF-1 Receptor.

PubMed

Fu, Shaoting; Yin, Lijun; Lin, Xiaojing; Lu, Jianqiang; Wang, Xiaohui

2018-06-02

Myoblast proliferation is crucial to skeletal muscle hypertrophy and regeneration. Our previous study indicated that mechanical stretch altered the proliferation of C2C12 myoblasts, associated with insulin growth factor 1 (IGF-1)-mediated phosphoinositide 3-kinase (PI3K)/Akt (also known as protein kinase B) and mitogen-activated protein kinase (MAPK) pathways through IGF-1 receptor (IGF-1R). The purpose of this study was to explore the same stretches on the proliferation of L6 myoblasts and its association with IGF-1-regulated PI3K/Akt and MAPK activations. L6 myoblasts were divided into three groups: control, 15% stretch, and 20% stretch. Stretches were achieved using FlexCell Strain Unit. Cell proliferation and IGF-1 concentration were detected by CCK8 and ELISA, respectively. IGF-1R expression, and expressions and activities of PI3K, Akt, and MAPKs (including extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38) were determined by Western blot. We found that 15% stretch promoted, while 20% stretch inhibited L6 myoblast proliferation. A 15% stretch increased IGF-1R level, although had no effect on IGF-1 secretion of L6 myoblasts, and PI3K/Akt and ERK1/2 (not p38) inhibitors attenuated 15% stretch-induced pro-proliferation. Exogenous IGF-1 reversed 20% stretch-induced anti-proliferation, accompanied with increases in IGF-1R level as well as PI3K/Akt and MAPK (ERK1/2 and p38) activations. In conclusion, stretch regulated L6 myoblasts proliferation, which may be mediated by the changes in PI3K/Akt and MAPK activations regulated by IGF-1R, despite no detectable IGF-1 from stretched L6 myoblasts.

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

Substance P activates both contractile and inflammatory pathways in lymphatics through the neurokinin receptors NK1R and NK3R.

PubMed

Chakraborty, Sanjukta; Nepiyushchikh, Zhanna; Davis, Michael J; Zawieja, David C; Muthuchamy, Mariappan

2011-01-01

The aim of this study was to elucidate the molecular signaling mechanisms by which substance P (SP) modulates lymphatic muscle contraction and to determine whether SP stimulates both contractile as well as inflammatory pathways in the lymphatics. A rat mesenteric lymphatic muscle cell culture model (RMLMCs) and known specific pharmacological inhibitors were utilized to delineate SP-mediated signaling pathways in lymphatics. We detected expression of neurokinin receptor 1 (NK1R) and neurokinin receptor 3 (NK3R) in RMLMCs. SP stimulation increased phosphorylation of myosin light chain 20 (MLC₂₀) as well as p38 mitogen associated protein kinase (p38-MAPK) and extracellular signal regulated kinase (ERK1/2) indicating activation of both a contractile and a pro-inflammatory MAPK pathway. Pharmacological inhibition of both NK1R and NK3R significantly affected the downstream SP signaling. We further examined whether there was any crosstalk between the two pathways upon SP stimulation. Inhibition of ERK1/2 decreased levels of p-MLC₂₀ after SP activation, in a PKC dependent manner, indicating a potential crosstalk between these two pathways. These data provide the first evidence that SP-mediated crosstalk between pro-inflammatory and contractile signaling mechanisms exists in the lymphatic system and may be an important bridge between lymphatic function modulation and inflammation. © 2010 John Wiley & Sons Ltd.

Substance P activates both contractile and inflammatory pathways in lymphatics through the neurokinin receptors NK1R and NK3R

PubMed Central

Chakraborty, Sanjukta; Nepiyushchikh, Zhanna; Davis, Michael J.; Zawieja, David C.; Muthuchamy, Mariappan

2010-01-01

Objective The aim of this study was to elucidate the molecular signaling mechanisms by which substance P (SP) modulates lymphatic muscle contraction and to determine whether SP stimulates both contractile as well as inflammatory pathways in the lymphatics. Methods A rat mesenteric lymphatic muscle cell culture model (RMLMCs) and known specific pharmacological inhibitors were utilized to delineate SP mediated signaling pathways in lymphatics. Results We detected expression of neurokinin receptor 1 (NK1R) and neurokinin receptor 3 (NK3R) in RMLMCs. SP stimulation increased phosphorylation of myosin light chain 20 (MLC20) as well as p38 mitogen associated protein kinase (p38-MAPK) and extracellular signal regulated kinase (ERK1/2) indicating activation of both a contractile and a pro-inflammatory MAPK pathway. Pharmacological inhibition of both NK1R and NK3R significantly affected the downstream SP signaling. We further examined whether there was any crosstalk between the two pathways upon SP stimulation. Inhibition of ERK1/2 decreased levels of p-MLC20 after SP activation, in a PKC dependent manner, indicating a potential crosstalk between these two pathways. Conclusions These data provide the first evidence that SP mediated crosstalk between pro-inflammatory and contractile signaling mechanisms exists in the lymphatic system and may be an important bridge between lymphatic function modulation and inflammation. PMID:21166923

Neuroprotective Effect of Curcumin Against Cerebral Ischemia-Reperfusion Via Mediating Autophagy and Inflammation.

PubMed

Huang, Lifa; Chen, Chengwei; Zhang, Xin; Li, Xu; Chen, Zupeng; Yang, Chao; Liang, Xiaolong; Zhu, Guochong; Xu, Zhen

2018-01-01

Curcumin, a polyphenolic compound extracted from Curcuma longa, has drawn attention for its effective bioactivities against ischemia-induced injury. This study aimed to evaluate the neuroprotective effect of curcumin and investigate the underlying mechanism that mediates autophagy and inflammation in an animal model of middle cerebral artery occlusion (MCAO) in rats. Curcumin was delivered to Sprague Dawley male rats at a dose of 200 mg/kg curcumin by intraperitoneal injection 30 min after ischemia-reperfusion (I/R). LY294002, a specific inhibitor of the PI3K/Akt/mTOR pathway, as well as anisomycin, an activator of TLR4/p38/MAPK, was administered by ventricle injection 30 min before MCAO. The same volume of saline was given as a control. Brain infarction and neurological function were determined 24 h post-MCAO. Immunoblotting and immunofluorescence were used to detect alterations in autophagy-relevant proteins Akt, p-Akt, mTOR, p-mTOR, LC3-II, and LC3-I, and inflammation-related proteins TLR4, p-38, p-p38, and IL-1 in the ipsilateral hemisphere. Cerebral I/R injury resulted in significant alterations of LC3-II/LC3-I, IL-1, TLR4, and p-p38. Curcumin in MCAO rats significantly improved brain damage and neurological function by upregulating p-Akt and p-mTOR and downregulating LC3-II/LC3-I, IL-1, TLR4, p-38, and p-p38. However, these protective effects against ischemia could be suppressed when LY294002 or anisomycin was included. Curcumin exerts neuroprotective effects by attenuating autophagic activities through mediating the PI3K/Akt/mTOR pathway, while also suppressing an inflammatory reaction by regulating the TLR4/p38/MAPK pathway. Furthermore, this study indicates that curcumin could be an effective therapy for patients afflicted with ischemia.

Estrogen suppresses breast cancer proliferation through GPER / p38 MAPK axis during hypoxia.

PubMed

Sathya, S; Sudhagar, S; Lakshmi, B S

2015-12-05

Breast cancer cells frequently experience hypoxia which is associated with resistance to hormonal therapy and poor clinical prognosis, making it important to understand the function of estrogen under hypoxic condition. Here, we demonstrate that estrogen suppresses breast cancer cell growth under hypoxia, through inhibition at G1/S phase of cell cycle, by elevation of p21 expression. The involvement of GPER in estrogen mediated growth arrest was elucidated using specific ligands and siRNA. Although, estrogen was observed to activate both p44/42 and p38 MAPK signaling, pharmacological inhibition and silencing of p38 MAPK abrogated the induction of p21 expression and growth arrest, during hypoxia. The involvement of estrogen induced ROS in the p38 MAPK mediated p21 expression and cell growth arrest was established by observing that scavenging of ROS by NAC abrogated p38 MAPK activation and p21 expression during hypoxia. In conclusion, Estrogen suppresses breast cancer growth by inhibiting G1/S phase transition through GPER/ROS/p38 MAPK/p21 mediated signaling during hypoxic condition. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Lidocaine attenuates lipopolysaccharide-induced inflammatory responses in microglia.

PubMed

Yuan, Tong; Li, Zhiwen; Li, Xinbai; Yu, Gaoqi; Wang, Na; Yang, Xige

2014-11-01

Lidocaine has been used as a local anesthetic with anti-inflammatory properties, but its effects on neuroinflammation have not been well defined. In the present study, we investigated the prophylactic effects of lidocaine on lipopolysaccharide (LPS)-activated microglia and explored the underlying mechanisms. Microglial cells were incubated with or without 1 μg/mL LPS in the presence or absence of lidocaine, a p38 mitogen-activated protein kinase (p38 MAPK) inhibitor (SB203580), a nuclear factor-kappa B (NF-κB) inhibitor (pyrrolidine dithiocarbamate), or small interfering RNA. The protein and expression levels of inflammatory mediators, such as monocyte chemotactic protein 1, nitric oxide, prostaglandin E2, interleukin 1β, and tumor necrosis factor α were measured using enzyme-linked immunosorbent assays and real-time polymerase chain reaction. The effect of lidocaine on NF-κB and p38 MAPK activation was evaluated using enzyme-linked immunosorbent assays, Western blot analysis, and electrophoretic mobility shift assay. Lidocaine (≥2 μg/mL) significantly inhibited the release and expression of nitric oxide, monocyte chemotactic protein 1, prostaglandin E2, interleukin 1β, and tumor necrosis factor α in LPS-activated microglia. Treatment with lidocaine also significantly inhibited the phosphorylation of p38 MAPK and the nuclear translocation of NF-κB p50/p65, increased the protein levels of inhibitor kappa B-α. Furthermore, our study shows that the LPS-induced release of inflammatory mediators was suppressed by SB203580, pyrrolidine dithiocarbamate, and small interfering RNA. Prophylactic treatment with lidocaine inhibits LPS-induced release of inflammatory mediators from microglia, and these effects may be mediated by blockade of p38 MAPK and NF-κB signaling pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

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/beta inhibitor, inhibited the secretion of inflammatory cytokines induced by TNF-α/IFN-γ in cultured HaCaT cells. The differential expression of TNF-α-R1 and IFN-γ-R1 was also observed after the stimulation of TNF-α/IFN-γ, which was significantly normalized after the icariin treatment. Collectively, we illustrated the anti-inflammatory property of icariin in human keratinocytes. These effects were mediated, at least partially, via the inhibition of substance P and the p38-MAPK signaling pathway, as well as by the regulation of the TNF-α-R1 and IFN-γ-R1 signals. Copyright © 2015 Elsevier B.V. All rights reserved.

Flavonoids from Orostachys japonicus A. Berger induces caspase-dependent apoptosis at least partly through activation of p38 MAPK pathway in U937 human leukemic cells.

PubMed

Lee, Won Sup; Yun, Jeong Won; Nagappan, Arulkumar; Jung, Ji Hyun; Yi, Sang Mi; Kim, Dong Hoon; Kim, Hye Jung; Kim, GonSup; Ryu, Chung Ho; Shin, Sung Chul; Hong, Soon Chan; Choi, Yung Hyun; Jung, Jin-Myung

2015-01-01

Orostachys japonicus A. Berger (A. Berger) is commonly used as a folk remedy for cancer therapy. However, the mechanisms of its anti-cancer activity are poorly investigated in human cancer cells. In this study, we investigated whether flavonoids extracted from Orostachys japonicus A. Berger (FEOJ) might have anticancer effects in human leukemia cells, focusing on cell death mechanisms. U937 human leukemic cancer cells were used. FEOJ induced apoptosis in a dose-dependent manner in human U937 cancer cells. Flow cytometry revealed significant accumulation of cells with sub-G1 DNA content at the concentrations of 200 μg/mL and 400 μg/mL. FEOJ-induced apoptosis was caspase-dependent through loss of mitochondrial membrane potential (MMP, ΔΨm) in human U937 cancer cells, which might be associated with suppression of Bcl-2 and XIAP proteins. FEOJ induced the p38 MAPK signaling pathway, playing at least in part an important role in FEOJ-induced apoptosis. This study suggested that FEOJ may induce caspase-dependent apoptosis in human leukemic cells by regulating MMP (ΔΨm) through suppressing Bcl-2 and X-IAP. In addition, the results indicated that upstream p38 MAPK signaling regulates the apoptotic effect of FEOJ. This study provides evidence that FEOJ might have anti-cancer potential for human leukemic cells.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chou, C.-T.; Department of Biological Sciences, National Sun Yat-sen University, 804, Taiwan; He Shiping

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 p38more » 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.« less

EETs Attenuate Ox-LDL-Induced LTB4 Production and Activity by Inhibiting p38 MAPK Phosphorylation and 5-LO/BLT1 Receptor Expression in Rat Pulmonary Arterial Endothelial Cells.

PubMed

Jiang, Jun-xia; Zhang, Shui-juan; Xiong, Yao-kang; Jia, Yong-liang; Sun, Yan-hong; Lin, Xi-xi; Shen, Hui-juan; Xie, Qiang-min; Yan, Xiao-feng

2015-01-01

Cytochrome P-450 epoxygenase (EPOX)-derived epoxyeicosatrienoic acids (EETs), 5-lipoxygenase (5-LO), and leukotriene B4 (LTB4), the product of 5-LO, all play a pivotal role in the vascular inflammatory process. We have previously shown that EETs can alleviate oxidized low-density lipoprotein (ox-LDL)-induced endothelial inflammation in primary rat pulmonary artery endothelial cells (RPAECs). Here, we investigated whether ox-LDL can promote LTB4 production through the 5-LO pathway. We further explored how exogenous EETs influence ox-LDL-induced LTB4 production and activity. We found that treatment with ox-LDL increased the production of LTB4 and further led to the expression and release of both monocyte chemoattractant protein-1 (MCP-1/CCL2) and intercellular adhesion molecule-1 (ICAM-1). All of the above ox-LDL-induced changes were attenuated by the presence of 11,12-EET and 14,15-EET, as these molecules inhibited the 5-LO pathway. Furthermore, the LTB4 receptor 1 (BLT1 receptor) antagonist U75302 attenuated ox-LDL-induced ICAM-1 and MCP-1/CCL2 expression and production, whereas LY255283, a LTB4 receptor 2 (BLT2 receptor) antagonist, produced no such effects. Moreover, in RPAECs, we demonstrated that the increased expression of 5-LO and BLT1 following ox-LDL treatment resulted from the activation of nuclear factor-κB (NF-κB) via the p38 mitogen-activated protein kinase (MAPK) pathway. Our results indicated that EETs suppress ox-LDL-induced LTB4 production and subsequent inflammatory responses by downregulating the 5-LO/BLT1 receptor pathway, in which p38 MAPK phosphorylation activates NF-κB. These results suggest that the metabolism of arachidonic acid via the 5-LO and EPOX pathways may present a mutual constraint on the physiological regulation of vascular endothelial cells.

EETs Attenuate Ox-LDL-Induced LTB4 Production and Activity by Inhibiting p38 MAPK Phosphorylation and 5-LO/BLT1 Receptor Expression in Rat Pulmonary Arterial Endothelial Cells

PubMed Central

Xiong, Yao-kang; Jia, Yong-liang; Sun, Yan-hong; Lin, Xi-xi; Shen, Hui-juan; Xie, Qiang-min; Yan, Xiao-feng

2015-01-01

Cytochrome P-450 epoxygenase (EPOX)-derived epoxyeicosatrienoic acids (EETs), 5-lipoxygenase (5-LO), and leukotriene B4 (LTB4), the product of 5-LO, all play a pivotal role in the vascular inflammatory process. We have previously shown that EETs can alleviate oxidized low-density lipoprotein (ox-LDL)-induced endothelial inflammation in primary rat pulmonary artery endothelial cells (RPAECs). Here, we investigated whether ox-LDL can promote LTB4 production through the 5-LO pathway. We further explored how exogenous EETs influence ox-LDL-induced LTB4 production and activity. We found that treatment with ox-LDL increased the production of LTB4 and further led to the expression and release of both monocyte chemoattractant protein-1 (MCP-1/CCL2) and intercellular adhesion molecule-1 (ICAM-1). All of the above ox-LDL-induced changes were attenuated by the presence of 11,12-EET and 14,15-EET, as these molecules inhibited the 5-LO pathway. Furthermore, the LTB4 receptor 1 (BLT1 receptor) antagonist U75302 attenuated ox-LDL-induced ICAM-1 and MCP-1/CCL2 expression and production, whereas LY255283, a LTB4 receptor 2 (BLT2 receptor) antagonist, produced no such effects. Moreover, in RPAECs, we demonstrated that the increased expression of 5-LO and BLT1 following ox-LDL treatment resulted from the activation of nuclear factor-κB (NF-κB) via the p38 mitogen-activated protein kinase (MAPK) pathway. Our results indicated that EETs suppress ox-LDL-induced LTB4 production and subsequent inflammatory responses by downregulating the 5-LO/BLT1 receptor pathway, in which p38 MAPK phosphorylation activates NF-κB. These results suggest that the metabolism of arachidonic acid via the 5-LO and EPOX pathways may present a mutual constraint on the physiological regulation of vascular endothelial cells. PMID:26035589

Chronic intermittent hypoxia induces liver fibrosis in mice with diet-induced obesity via TLR4/MyD88/MAPK/NF-kB signaling pathways.

PubMed

Kang, Hyeon Hui; Kim, In Kyoung; Lee, Hye In; Joo, Hyonsoo; Lim, Jeong Uk; Lee, Jongmin; Lee, Sang Haak; Moon, Hwa Sik

2017-08-19

Obstructive sleep apnea (OSA) is associated with nonalcoholic fatty liver disease (NAFLD), and causes chronic intermittent hypoxia (CIH) during sleep. Inflammation is associated with the development of metabolic complications induced by CIH. Research suggests that innate immune mechanisms are involved in the pro-inflammatory pathways of liver fibrosis. The purpose of this study was to investigate whether innate immune responses induce liver fibrosis, and to evaluate mechanisms underlying hepatic inflammation related to CIH in a murine diet-induced obesity (DIO) model. Inflammatory and oxidative stress markers, TLR4, MyD88, Toll/interleukin-1-receptor-domain-containing adaptor-inducing interferon-β (TRIF), I-κB, NF-κB, p38 MAPK, c-JNK, and ERK activation, were measured in the serum and liver. As a result, α1(I)-collagen mRNA was significantly higher in DIO mice exposed to CIH than in the control groups. CIH mice exhibited liver fibrosis and significantly higher protein expression of TLR4, MyD88, phosphorylated (phospho-) I-κB, and phospho-ERK1/2 activation in the liver, and higher expression of NF-κB than that in the controls. TRIF, p38 MAPK, and JNK activation did not differ significantly between groups. We conclude that CIH in DIO mice leads to liver fibrosis via TLR4/MyD88/MAPK/NF-kB signaling pathways. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

MAPK/p38 regulation of cytoskeleton rearrangement accelerates induction of macrophage activation by TLR4, but not TLR3.

PubMed

Bian, Hongjun; Li, Feifei; Wang, Wenwen; Zhao, Qi; Gao, Shanshan; Ma, Jincai; Li, Xiao; Ren, Wanhua; Qin, Chengyong; Qi, Jianni

2017-11-01

Toll-like receptor 3 (TLR3) and TLR4 utilize adaptor proteins to activate mitogen‑activated protein kinase (MAPK), resulting in the acute but transient inflammatory response aimed at the clearance of pathogens. In the present study, it was demonstrated that macrophage activation by lipopolysaccharide (LPS) or poly(I:C), leading to changes in cell morphology, differed significantly between the mouse macrophage cell line RAW264.7 and mouse primary peritoneal macrophages. Moreover, the expression of α- and β-tubulin was markedly decreased following LPS stimulation. By contrast, α- and β-tubulin expression were only mildly increased following poly(I:C) treatment. However, the expression of β-actin and GAPDH was not significantly affected. Furthermore, it was verified that vincristine pretreatment abrogated the cytoskeleton rearrangement and decreased the synthesis and secretion of proinflammatory cytokines and migration of macrophages caused by LPS. Finally, it was observed that the MAPK/p38 signaling pathway regulating cytoskeleton rearrangement may participate in LPS‑induced macrophage cytokine production and migration. Overall, the findings of the present study indicated that MAPK/p38 regulation of the cytoskeleton, particularly tubulin proteins, plays an important role in LPS-induced inflammatory responses via alleviating the synthesis and secretion of proinflammatory cytokines and inhibiting the migration of macrophages.

Complete inhibition of anisomycin and UV radiation but not cytokine induced JNK and p38 activation by an aryl-substituted dihydropyrrolopyrazole quinoline and mixed lineage kinase 7 small interfering RNA.

PubMed

Wang, Xushan; Mader, Mary M; Toth, John E; Yu, Xiaohong; Jin, Najia; Campbell, Robert M; Smallwood, Jeffrey K; Christe, Michael E; Chatterjee, Arindam; Goodson, Theodore; Vlahos, Chris J; Matter, William F; Bloem, Laura J

2005-05-13

Mixed lineage kinase 7 (MLK7) is a mitogen-activated protein kinase kinase kinase (MAPKKK) that activates the pro-apoptotic signaling pathways p38 and JNK. A library of potential kinase inhibitors was screened, and a series of dihydropyrrolopyrazole quinolines was identified as highly potent inhibitors of MLK7 in vitro catalytic activity. Of this series, an aryl-substituted dihydropyrrolopyrazole quinoline (DHP-2) demonstrated an IC50 of 70 nM for inhibition of pJNK formation in COS-7 cell MLK7/JNK co-transfection assays. In stimulated cells, DHP-2 at 200 nM or MLK7 small interfering RNA completely blocked anisomycin and UV induced but had no effect on interleukin-1beta or tumor necrosis factor-alpha-induced p38 and JNK activation. Additionally, the compound blocked anisomycin and UV-induced apoptosis in COS-7 cells. Heart tissue homogenates from MLK7 transgenic mice treated with DHP-2 at 30 mg/kg had reduced JNK and p38 activation with no apparent effect on ERK activation, demonstrating that this compound can be used to block MLK7-driven MAPK pathway activation in vivo. Taken together, these data demonstrate that MLK7 is the MAPKKK required for modulation of the stress-activated MAPKs downstream of anisomycin and UV stimulation and that DHP-2 can be used to block MLK7 pathway activation in cells as well as in vivo.

MAPK Usage in Periodontal Disease Progression

PubMed Central

Li, Qiyan; Valerio, Michael S.; Kirkwood, Keith L.

2012-01-01

In periodontal disease, host recognition of bacterial constituents, including lipopolysaccharide (LPS), induces p38 MAPK activation and subsequent inflammatory cytokine expression, favoring osteoclastogenesis and increased net bone resorption in the local periodontal environment. In this paper, we discuss evidence that the p38/MAPK-activated protein kinase-2 (MK2) signaling axis is needed for periodontal disease progression: an orally administered p38α inhibitor reduced the progression of experimental periodontal bone loss by reducing inflammation and cytokine expression. Subsequently, the significance of p38 signaling was confirmed with RNA interference to attenuate MK2-reduced cytokine expression and LPS-induced alveolar bone loss. MAPK phosphatase-1 (MKP-1), a negative regulator of MAPK activation, was also critical for periodontal disease progression. In MPK-1-deficient mice, p38-sustained activation increased osteoclast formation and bone loss, whereas MKP-1 overexpression dampened p38 signaling and subsequent cytokine expression. Finally, overexpression of the p38/MK2 target RNA-binding tristetraprolin (TTP) decreased mRNA stability of key inflammatory cytokines at the posttranscriptional level, thereby protecting against periodontal inflammation. Collectively, these studies highlight the importance of p38 MAPK signaling in immune cytokine production and periodontal disease progression. PMID:22315682

Formononetin-induced apoptosis by activation of Ras/p38 mitogen-activated protein kinase in estrogen receptor-positive human breast cancer cells.

PubMed

Chen, J; Sun, L

2012-12-01

Formononetin is one of the main active components of red clover plants, and considered as a phytoestrogen. Its pharmacological effects in vivo may be either estrogenic or anti-estrogenic, mainly depending upon the estrogen levels. Our recent studies suggested that formononetin inactivated IGF1/IGF1R-PI3K/Akt pathways and decreased cyclin D1 mRNA and protein expression in human breast cancer cells in vitro and in vivo. In the present study, we further investigated the molecular mechanisms involved in the induced apoptosis effect of formononetin on breast cancer cells. Our results suggested that formononetin inhibited the proliferation of ER-positive MCF-7 cells and T47D cells. In contrast, formononetin could not inhibit the cell of growth of ER-negative breast cancer cells such as MDA-MB-435 S cells. We further found that formononetin activated MAPK signaling pathway in a dose-dependent manner, which resulted in the increased ratio of Bax/Bcl-2, and induced apoptosis on MCF-7 cells. However, when MCF-7 cells were pretreated with p38MAPK inhibitor SB203580 before formononetin, apoptosis induced by formononetin was significantly attenuated. Thus, we conclude that the induced apoptosis effect of formononetin on human breast cancer cells were related to Ras-p38MAPK pathway. Considering that red clover plants are widely used clinically, our results provide the foundation for future development of formononetin for treatment of ER-positive breast cancer. © Georg Thieme Verlag KG Stuttgart · New York.

Sulforaphane attenuates microglia-mediated neuronal necroptosis through down-regulation of MAPK/NF-κB signaling pathways in LPS-activated BV-2 microglia.

PubMed

Qin, Sisi; Yang, Canhong; Huang, Weihua; Du, Shuhua; Mai, Hantao; Xiao, Jijie; Lü, Tianming

2018-01-31

Sulforaphane (SFN), a natural dietary isothiocyanate in cruciferous vegetables such as broccoli and cabbage, has very strong anti-inflammatory activity. Activation of microglia leads to overexpression of a series of pro-inflammatory mediators, which play a vital role in neuronal damage. SFN may have neuroprotective effects in different neurodegenerative diseases related to inflammation. However, the mechanisms underlying SFN's protection of neurons against microglia-mediated neuronal damage are not fully understood. Here, we investigated how SFN attenuated microglia-mediated neuronal damage. Our results showed that SFN could not directly protect the viability of neurons following pro-inflammatory mediators, but increased the viability of BV-2 microglia and down-regulated the mRNA and protein levels of pro-inflammatory mediators including TNF-α, IL-1β, IL-6 and iNOS in a concentration-dependent manner in BV-2 cells. SFN also significantly blocked the phosphorylation of MAPKs (p38, JNK, and ERK1/2) and NF-κB p65, both by itself and with MAPK inhibitors (SB203580, SP 600125, and U0126) or an NF-κB inhibitor (PDTC). The expression of pro-inflammatory proteins was also blocked by SFN with or without inhibitors. Further, SFN indirectly increased the viability and maintained the morphology of neurons, and the protein expression of RIPK3 and MLKL was significantly suppressed by SFN in neuronal necroptosis through p38, JNK, and NF-κB p65 but not ERK1/2 signaling pathways. Together, our results demonstrate that SFN attenuates LPS-induced pro-inflammatory responses through down-regulation of MAPK/NF-κB signaling pathway in BV-2 microglia and thus indirectly suppresses microglia-mediated neuronal damage. Copyright © 2018 Elsevier Ltd. All rights reserved.

Differential roles of PKC isoforms (PKCs) and Ca2+ in GnRH and phorbol 12-myristate 13-acetate (PMA) stimulation of p38MAPK phosphorylation in immortalized gonadotrope cells.

PubMed

Mugami, Shany; Kravchook, Shani; Rahamim-Ben Navi, Liat; Seger, Rony; Naor, Zvi

2017-01-05

We examined the role of PKCs and Ca 2+ in GnRH-stimulated p38MAPK phosphorylation in the gonadotrope derived αT3-1 and LβT2 cell lines. GnRH induced a slow and rapid increase in p38MAPK phosphorylation in αT3-1 and LβT2 cells respectively, while PMA gave a slow response. The use of dominant negatives for PKCs and peptide inhibitors for the receptors for activated C kinase (RACKs), has revealed differential role for PKCα, PKCβII, PKCδ and PKCε in p38MAPK phosphorylation in a ligand-and cell context-dependent manner. The paradoxical findings that PKCs activated by GnRH and PMA play a differential role in p38MAPK phosphorylation may be explained by differential localization of the PKCs. Basal, GnRH- and PMA- stimulation of p38MAPK phosphorylation in αT3-1 cells is mediated by Ca 2+ influx via voltage-gated Ca 2+ channels and Ca 2+ mobilization, while in the differentiated LβT2 gonadotrope cells it is mediated only by Ca 2+ mobilization. p38MAPK resides in the cell membrane and is relocated to the nucleus by GnRH (∼5 min). Thus, we have identified the PKCs and the Ca 2+ pools involved in GnRH stimulated p38MAPK phosphorylation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Serine 209 resides within a putative p38(MAPK) consensus motif and regulates monoamine oxidase-A activity.

PubMed

Cao, Xia; Rui, Lewei; Pennington, Paul R; Chlan-Fourney, Jennifer; Jiang, Zhongjian; Wei, Zelan; Li, Xin-Min; Edmondson, Dale E; Mousseau, Darrell D

2009-10-01

The p38 mitogen-activated protein kinase (MAPK) cascade as well as the enzyme monoamine oxidase-A (MAO-A) have both been associated with oxidative stress. We observed that the specific inhibition of the p38(MAPK) protein [using either a chemical inhibitor or a dominant-negative p38(MAPK) clone] selectively induces MAO-A activity and MAO-A-sensitive toxicity in several neuronal cell lines, including primary cortical neurons. Over-expression of a constitutively active p38(MAPK) results in the phosphorylation of the MAO-A protein and inhibition of MAO-A activity. The MAO-A(Ser209Glu) phosphomimic - bearing a targeted substitution within a putative p38(MAPK) consensus motif - is neither active nor neurotoxic. In contrast, the MAO-A(Ser209Ala) variant (mimics dephosphorylation) does not associate with p38(MAPK), and is both very active and very toxic. Substitution of the homologous serine in the MAO-B isoform, i.e. Ser200, with either Glu or Ala does not affect the catalytic activity of the corresponding over-expressed proteins. These combined in vitro data strongly suggest a direct p38(MAPK)-dependent inhibition of MAO-A function. Based on published observations, this endogenous means of selectively regulating MAO-A function could provide for an adaptive response to oxidative stress associated with disorders as diverse as depression, reperfusion/ischemia, and the early stages of Alzheimer's disease.

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

2017-05-01

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Guang-Lin; Department of Pharmacology, University of Michigan, Ann Arbor; Du, Yi-Fang

KYKZL-1, a newly synthesized compound with COX/5-LOX dual inhibition, was subjected to the anti-inflammatory activity test focusing on its modulation of inflammatory mediators as well as intracellular MAPK and NF-κB signaling pathways. In acute ear edema model, pretreatment with KYKZL-1 (p.o.) dose-dependently inhibited the xylene-induced ear edema in mice with a higher inhibition than diclofenac. In a three-day TPA-induced inflammation, KYKZL-1 also showed significant anti-inflammatory activity with inhibition ranging between 20% and 64%. In gastric lesion test, KYKZL-1 elicited markedly fewer stomach lesions with a low index of ulcer as compared to diclofenac in rats. In further studies, KYKZL-1 wasmore » found to significantly inhibit the production of NO, PGE{sub 2}, LTB{sub 4} in LPS challenged RAW264.7, which is parallel to its attenuation of the expression of iNOS, COX-2, 5-LOX mRNAs or proteins and inhibition of phosphorylation of p38 and ERK MAPKs and activation of NF-κB. Taken together, our data indicate that KYKZL-1 comprises dual inhibition of COX and 5-LOX and exerts an obvious anti-inflammatory activity with an enhanced gastric safety profile via simultaneous inhibition of phosphorylation of p38 and ERK MAPKs and activation of NF-κB. - Highlights: • KYKZL-1 is designed to exhibit COX/5-LOX dual inhibition. • KYKZL-1 inhibits NO, PGE{sub 2} and LTB{sub 4} and iNOS, COX-2 and 5-LOX mRNAs and MAPKs. • KYKZL-1 inhibits phosphorylation of MAPKs. • KYKZL-1 inactivates NF-κB pathway.« less

Src Family Kinases and p38 Mitogen-Activated Protein Kinases Regulate Pluripotent Cell Differentiation in Culture

PubMed Central

Tan, Boon Siang Nicholas; Kwek, Joly; Wong, Chong Kum Edwin; Saner, Nicholas J.; Yap, Charlotte; Felquer, Fernando; Morris, Michael B.; Gardner, David K.; Rathjen, Peter D.; Rathjen, Joy

2016-01-01

Multiple pluripotent cell populations, which together comprise the pluripotent cell lineage, have been identified. The mechanisms that control the progression between these populations are still poorly understood. The formation of early primitive ectoderm-like (EPL) cells from mouse embryonic stem (mES) cells provides a model to understand how one such transition is regulated. EPL cells form from mES cells in response to l-proline uptake through the transporter Slc38a2. Using inhibitors of cell signaling we have shown that Src family kinases, p38 MAPK, ERK1/2 and GSK3β are required for the transition between mES and EPL cells. ERK1/2, c-Src and GSK3β are likely to be enforcing a receptive, primed state in mES cells, while Src family kinases and p38 MAPK are involved in the establishment of EPL cells. Inhibition of these pathways prevented the acquisition of most, but not all, features of EPL cells, suggesting that other pathways are required. L-proline activation of differentiation is mediated through metabolism and changes to intracellular metabolite levels, specifically reactive oxygen species. The implication of multiple signaling pathways in the process suggests a model in which the context of Src family kinase activation determines the outcomes of pluripotent cell differentiation. PMID:27723793

L-Ascorbate Attenuates the Endotoxin-Induced Production of Inflammatory Mediators by Inhibiting MAPK Activation and NF-κB Translocation in Cortical Neurons/Glia Cocultures

PubMed Central

Huang, Ya-Ni; Lai, Chien-Cheng; Chiu, Chien-Tsai; Lin, Jhen-Jhe; Wang, Jia-Yi

2014-01-01

In response to acute insults to the central nervous system, such as pathogen invasion or neuronal injuries, glial cells become activated and secrete inflammatory mediators such as nitric oxide (NO), cytokines, and chemokines. This neuroinflammation plays a crucial role in the pathophysiology of chronic neurodegenerative diseases. Endogenous ascorbate levels are significantly decreased among patients with septic encephalopathy. Using the bacterial endotoxin lipopolysaccharide (LPS) to induce neuroinflammation in primary neuron/glia cocultures, we investigated how L-ascorbate (vitamin C; Vit. C) affected neuroinflammation. LPS (100 ng/ml) induced the expression of inducible NO synthase (iNOS) and the production of NO, interleukin (IL)-6, and macrophage inflammatory protein-2 (MIP-2/CXCL2) in a time-dependent manner; however, cotreatment with Vit. C (5 or 10 mM) attenuated the LPS-induced iNOS expression and production of NO, IL-6, and MIP-2 production. The morphological features revealed after immunocytochemical staining confirmed that Vit. C suppressed LPS-induced astrocytic and microglial activation. Because Vit. C can be transported into neurons and glia via the sodium-dependent Vit. C transporter-2, we examined how Vit. C affected LPS-activated intracellular signaling in neuron/glia cocultures. The results indicated the increased activation (caused by phosphorylation) of mitogen-activated protein kinases (MAPKs), such as p38 at 30 min and extracellular signal-regulated kinases (ERKs) at 180 min after LPS treatment. The inhibition of p38 and ERK MAPK suppressed the LPS-induced production of inflammatory mediators. Vit. C also inhibited the LPS-induced activation of p38 and ERK. Combined treatments of Vit. C and the inhibitors of p38 and ERK yielded no additional inhibition compared with using the inhibitors alone, suggesting that Vit. C functions through the same signaling pathway (i.e., MAPK) as these inhibitors. Vit. C also reduced LPS-induced IκB-α degradation and NF-κB translocation. Thus, Vit. C suppressed the LPS-stimulated production of inflammatory mediators in neuron/glia cocultures by inhibiting the MAPK and NF-κB signaling pathways. PMID:24983461

Induction of Apoptosis and Nonsteroidal Antiinflammatory Drug-Activated Gene 1 in Pancreatic Cancer Cells By A Glycyrrhetinic Acid Derivative

PubMed Central

Jutooru, Indira; Chadalapaka, Gayathri; Chintharlapalli, Sudhakar; Papineni, Sabitha; Safe, Stephen

2009-01-01

Methyl 2-cyano-3,11-dioxo-18β-olean-1,12-dien-30-oate (CDODA-Me) is a synthetic triterpenoid derived from glycyrrhetinic acid, a bioactive phytochemical in licorice, CDODA-Me inhibits growth of Panc1 and Panc28 pancreatic cancer cell lines and activates peroxisome proliferator-activated receptor γ (PPARγ)-dependent transactivation in these cells. CDODA-Me also induced p21 and p27 protein expression and downregulates cyclin D1; however, these responses were receptor-independent. CDODA-Me induced apoptosis in Panc1 and Panc28 cells, and this was accompanied by receptor-independent induction of the proapoptotic proteins early growth response-1 (Egr-1), nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1), and activating transcription factor-3 (ATF3). Induction of NAG-1 and Egr-1 by CDODA-Me was dependent on activation of phosphatidylinositol-3-kinase (PI3-K) and/or p42 and p38 mitogen-activated protein kinase (MAPK) pathways but there were differences between Panc28 and Panc1 cells. Induction of NAG-1 in Panc28 cells was p38-MAPK- and PI3-K-dependent but Egr-1-independent, whereas induction in Panc1 cells was associated with activation of p38-MAPK, PI3-K and p42-MAPK and was only partially Egr-1-dependent. This is the first report of the induction of the proapoptotic protein NAG-1 in pancreatic cancer cells. PMID:19125423

The chalcone flavokawain B induces G2/M cell-cycle arrest and apoptosis in human oral carcinoma HSC-3 cells through the intracellular ROS generation and downregulation of the Akt/p38 MAPK signaling pathway.

PubMed

Hseu, You-Cheng; Lee, Meng-Shiou; Wu, Chi-Rei; Cho, Hsin-Ju; Lin, Kai-Yuan; Lai, Guan-Hua; Wang, Sheng-Yang; Kuo, Yueh-Hsiung; Kumar, K J Senthil; Yang, Hsin-Ling

2012-03-07

Chalcones have been described to represent cancer chemopreventive food components that are rich in fruits and vegetables. In this study, we examined the anti-oral cancer effect of flavokawain B (FKB), a naturally occurring chalcone isolated from Alpinia pricei (shell gingers), and revealed its molecular mechanism of action. Treatment of human oral carcinoma (HSC-3) cells with FKB (1.25-10 μg/mL; 4.4-35.2 μM) inhibited cell viability and caused G(2)/M arrest through reductions in cyclin A/B1, Cdc2, and Cdc25C levels. Moreover, FKB treatment resulted in the induction of apoptosis, which was associated with DNA fragmentation, mitochondria dysfunction, cytochrome c and AIF release, caspase-3 and caspase-9 activation, and Bcl-2/Bax dysregulation. Furthermore, increased Fas activity and procaspase-8, procaspase-4, and procaspase-12 cleavages were accompanied by death receptor and ER-stress, indicating the involvement of mitochondria, death-receptor, and ER-stress signaling pathways. FKB induces apoptosis through ROS generation as evidenced by the upregulation of oxidative-stress markers HO-1/Nrf2. This mechanism was further confirmed by the finding that the antioxidant N-acetylcysteine (NAC) significantly blocked ROS generation and consequently inhibited FKB-induced apoptosis. Moreover, FKB downregulated the phosphorylation of Akt and p38 MAPK, while their inhibitors LY294002 and SB203580, respectively, induced G(2)/M arrest and apoptosis. The profound reduction in cell number was observed in combination treatment with FKB and Akt/p38 MAPK inhibitors, indicating that the disruption of Akt and p38 MAPK cascades plays a functional role in FKB-induced G(2)/M arrest and apoptosis in HSC-3 cells.

The inhibitory effect of dexamethasone on platelet-derived growth factor-induced vascular smooth muscle cell migration through up-regulating PGC-1{alpha} expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Wei; Department of cardiology, the Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, Harbin 150081; Guo, Ting

2011-05-01

Dexamethasone has been shown to inhibit vascular smooth muscle cell (VSMC) migration, which is required for preventing restenosis. However, the mechanism underlying effect of dexamethasone remains unknown. We have previously demonstrated that peroxisome proliferator-activated receptor gamma (PPAR{gamma}) coactivator-1 alpha (PGC-1{alpha}) can inhibit VSMC migration and proliferation. Here, we investigated the role of PGC-1{alpha} in dexamethasone-reduced VSMC migration and explored the possible mechanism. We first examined PGC-1{alpha} expression in cultured rat aortic VSMCs. The results revealed that incubation of VSMCs with dexamethasone could significantly elevate PGC-1{alpha} mRNA expression. In contrast, platelet-derived growth factor (PDGF) decreased PGC-1{alpha} expression while stimulating VSMC migration.more » Mechanistic study showed that suppression of PGC-1{alpha} by small interfering RNA strongly abrogated the inhibitory effect of dexamethasone on VSMC migration, whereas overexpression of PGC-1{alpha} had the opposite effect. Furthermore, an analysis of MAPK signal pathways showed that dexamethasone inhibited ERK and p38 MAPK phosphorylation in VSMCs. Overexpression of PGC-1{alpha} decreased both basal and PDGF-induced p38 MAPK phosphorylation, but it had no effect on ERK phosphorylation. Finally, inhibition of PPAR{gamma} activation by a PPAR{gamma} antagonist GW9662 abolished the suppressive effects of PGC-1{alpha} on p38 MAPK phosphorylation and VSMC migration. These effects of PGC-1{alpha} were enhanced by a PPAR{gamma} agonist troglitazone. Collectively, our data indicated for the first time that one of the anti-migrated mechanisms of dexamethasone is due to the induction of PGC-1{alpha} expression. PGC-1{alpha} suppresses PDGF-induced VSMC migration through PPAR{gamma} coactivation and, consequently, p38 MAPK inhibition.« less

Curcumin, a Curcuma longa constituent, acts on MAPK p38 pathway modulating COX-2 and iNOS expression in chronic experimental colitis.

PubMed

Camacho-Barquero, Laura; Villegas, Isabel; Sánchez-Calvo, Juan Manuel; Talero, Elena; Sánchez-Fidalgo, Susana; Motilva, Virginia; Alarcón de la Lastra, Catalina

2007-03-01

Ulcerative colitis (UC) is a nonspecific inflammatory disorder characterized by oxidative and nitrosative stress, leucocyte infiltration and up-regulation of pro-inflammatory cytokines. Mitogen-activated protein kinases (MAPKs), such as the p38 and the c-Jun N-terminal kinase (JNK) modulate the transcription of many genes involved in the inflammatory process. Curcumin is a polyphenol derived from Curcuma longa, which is known to have anti-inflammatory activity. The aim of this study was to study the effects and mechanisms of action of curcumin, on chronic colitis in rats. Inflammation response was assessed by histology and myeloperoxidase activity (MPO). We determined the production of Th1 and Th2 cytokines and nitrites in colon mucosa, as well as the expression of inducible nitric oxide synthase (iNOS), cyclo-oxygenase(COX)-1 and-2 by western blotting and inmmunohistochemistry. Finally, we studied the involvement of MAPKs signaling in the protective effect of curcumin in chronic colonic inflammation. Curcumin (50-100 mg/kg/day) were administered by oral gavage 24 h after trinitrobenzensulfonic acid (TNBS) instillation, and daily during 2 weeks before sacrifice. Curcumin significantly attenuated the damage and caused substantial reductions of the rise in MPO activity and tumour necrosis factor alpha (TNF)-alpha. Also curcumine was able to reduce nitrites colonic levels and induced down-regulation of COX-2 and iNOS expression, and a reduction in the activation of p38 MAPK; however, no changes in the activation of JNK could be observed. In conclusion, we suggest that inhibition of p38 MAPK signaling by curcumin could explain the reduced COX-2 and iNOS immunosignals and the nitrite production in colonic mucosa reducing the development of chronic experimental colitis.

Long-term low-dose α-particle enhanced the potential of malignant transformation in human bronchial epithelial cells through MAPK/Akt pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Weili; Xiao, Linlin; Dong, Chen

2014-05-09

Highlights: • Multi-exposures of 25 mGy α-ray enhanced cell proliferation, adhesion, and invasion. • MAPK/Akt but not JNK/P66 was positively correlated with cell invasive phenotypes. • LDR of α-irradiation triggers cell malignant transformation through MAPK/Akt. - Abstract: Since the wide usage of ionizing radiation, the cancer risk of low dose radiation (LDR) (<0.1 Gy) has become attractive for a long time. However, most results are derived from epidemiologic studies on atomic-bomb survivors and nuclear accidents surrounding population, and the molecular mechanism of this risk is elusive. To explore the potential of a long-term LDR-induced malignant transformation, human bronchial epithelial cellsmore » Beas-2B were fractionally irradiated with 0.025 Gy α-particles for 8 times in total and then further cultured for 1–2 months. It was found that the cell proliferation, the abilities of adhesion and invasion, and the protein expressions of p-ERK, p-Akt, especially p-P38 were not only increased in the multiply-irradiated cells but also in their offspring 1–2 months after the final exposure, indicating high potentiality of cell malignant transformation. On opposite, the expressions of p-JNK and p-P66 were diminished in the subcultures of irradiated cells and thus may play a role of negative regulation in canceration. When the cells were transferred with p38 siRNA, the LDR-induced enhancements of cell adhesion and invasion were significantly reduced. These findings suggest that long-term LDR of α-particles could enhance the potential of malignant transformation incidence in human bronchial epithelial cells through MAPK/Akt pathway.« less

Arctigenin induces the apoptosis of primary effusion lymphoma cells under conditions of glucose deprivation.

PubMed

Baba, Yusuke; Shigemi, Zenpei; Hara, Naoko; Moriguchi, Misato; Ikeda, Marina; Watanabe, Tadashi; Fujimuro, Masahiro

2018-02-01

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of primary effusion lymphoma (PEL) and Kaposi's sarcoma. PEL is a type of non-Hodgkin's B-cell lymphoma, affecting immunosuppressed individuals, such as post-transplant or AIDS patients. However, since PEL is resistant to chemotherapeutic regimens, new effective treatment strategies are required. Arctigenin, a natural lignan compound found in the plant Arctium lappa, has been widely investigated as a potential anticancer agent in the clinical setting. In the present study, we examined the cytotoxic effects of arctigenin by cell viability assay and found that arctigenin markedly inhibited the proliferation of PEL cells compared with KSHV-uninfected B-lymphoma cells under conditions of glucose deprivation. Arctigenin decreased cellular ATP levels, disrupted mitochondrial membrane potential and triggered caspase-9-mediated apoptosis in the glucose-deprived PEL cells. In addition, western blot analysis using phospho-specific antibodies were used to evaluate activity changes in the signaling pathways of interest. As a result, arctigenin suppressed the activation of the extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (p38 MAPK) signaling pathways by inhibiting ERK and p38 MAPK phosphorylation in the glucose-deprived PEL cells. We confirmed that an inhibitor of ERK (U0126) or p38 MAPK (SB202190 and SB203580) suppressed the proliferation of the BC3 PEL cells compared with the KSHV-negative DG75 cells. Moreover, RT-PCR and luciferase reporter assay revealed that arctigenin and p38 MAPK inhibition by SB202190 or SB203580 downregulated the transcriptional expression of unfolded protein response (UPR)‑related molecules, including GRP78 and ATF6α under conditions of glucose deprivation. Finally, we confirmed that arctigenin did not affect KSHV replication in PEL cells, suggesting that arctigenin treatment for PEL does not contribute to the risk of de novo KSHV production. These data thus indicate that arctigenin may serve as a lead compound for the development of novel and effective drugs for the treatment of PEL.

Trichomonas vaginalis Induces Production of Proinflammatory Cytokines in Mouse Macrophages Through Activation of MAPK and NF-κB Pathways Partially Mediated by TLR2

PubMed Central

Li, Ling; Li, Xin; Gong, Pengtao; Zhang, Xichen; Yang, Zhengtao; Yang, Ju; Li, Jianhua

2018-01-01

Trichomoniasis, caused by Trichomonas vaginalis infection, is the most prevalent sexually transmitted disease in female and male globally. However, the mechanisms by innate immunity against T. vaginalis infection have not been fully elucidated. Toll-like receptor2 (TLR2) has been shown to be involved in pathogen recognition, innate immunity activation, and inflammatory response to the pathogens. Nonetheless, the function of TLR2 against T. vaginalis remains unclear. In the present study, we investigated the role of TLR2 in mouse macrophages against T. vaginalis. RT-qPCR analysis revealed that T. vaginalis stimulation increased the gene expression of TLR2 in wild-type (WT) mouse macrophages. T. vaginalis also induced the secretion of IL-6, TNF-α, and IFN-γ in WT mouse macrophages, and the expression of these cytokines significantly decreased in TLR2-/- mouse macrophages and in WT mouse macrophages pretreated with MAPK inhibitors SB203580 (p38) and PD98059 (ERK). Western blot analysis demonstrated that T. vaginalis stimulation induced the activation of p38, ERK, and p65 NF-κB signal pathways in WT mouse macrophages, and the phosphorylation of p38, ERK, and p65 NF-κB significantly decreased in TLR2-/- mouse macrophages. Taken together, our data suggested that T. vaginalis may regulates proinflammatory cytokines production by activation of p38, ERK, and NF-κB p65 signal pathways via TLR2 in mouse macrophages. TLR2 might be involved in the defense and elimination of T. vaginalis infection. PMID:29692771

Trichomonas vaginalis Induces Production of Proinflammatory Cytokines in Mouse Macrophages Through Activation of MAPK and NF-κB Pathways Partially Mediated by TLR2.

PubMed

Li, Ling; Li, Xin; Gong, Pengtao; Zhang, Xichen; Yang, Zhengtao; Yang, Ju; Li, Jianhua

2018-01-01

Trichomoniasis, caused by Trichomonas vaginalis infection, is the most prevalent sexually transmitted disease in female and male globally. However, the mechanisms by innate immunity against T. vaginalis infection have not been fully elucidated. Toll-like receptor2 (TLR2) has been shown to be involved in pathogen recognition, innate immunity activation, and inflammatory response to the pathogens. Nonetheless, the function of TLR2 against T. vaginalis remains unclear. In the present study, we investigated the role of TLR2 in mouse macrophages against T. vaginalis . RT-qPCR analysis revealed that T. vaginalis stimulation increased the gene expression of TLR2 in wild-type (WT) mouse macrophages. T. vaginalis also induced the secretion of IL-6, TNF-α, and IFN-γ in WT mouse macrophages, and the expression of these cytokines significantly decreased in TLR 2-/- mouse macrophages and in WT mouse macrophages pretreated with MAPK inhibitors SB203580 (p38) and PD98059 (ERK). Western blot analysis demonstrated that T. vaginalis stimulation induced the activation of p38, ERK, and p65 NF-κB signal pathways in WT mouse macrophages, and the phosphorylation of p38, ERK, and p65 NF-κB significantly decreased in TLR2 -/- mouse macrophages. Taken together, our data suggested that T. vaginalis may regulates proinflammatory cytokines production by activation of p38, ERK, and NF-κB p65 signal pathways via TLR2 in mouse macrophages. TLR2 might be involved in the defense and elimination of T. vaginalis infection.

[Inhibitory effect of exogenous insulin-like growth factor binding protein 7 on proliferation of human breast cancer cell line MDA-MB-453 and its mechanism].

PubMed

Yuan, Lei; Fan, Wen-Juan; Yang, Xu-Guang; Rao, Shu-Mei; Song, Jin-Ling; Song, Guo-Hua

2013-10-25

The present study was to investigate the effects of exogenous insulin-like growth factor binding protein 7 (IGFBP7) on the proliferation of human breast cancer cell line MDA-MB-453 and its possible mechanism. By means of MTT method in vitro, the results showed exogenous IGFBP7 inhibited the growth of MDA-MB-453 cells (IC50 of IGFBP7 = 8.49 μg/mL) in time- and concentration-dependent manner. SB203580, p38(MAPK) inhibitor, blocked the anti-proliferative effect of exogenous IGFBP7. The flow cytometry assay showed that exogenous IGFBP7 remarkably induced G0/G1 arrest in MDA-MB-453 cells. The Western blot showed that exogenous IGFBP7 promoted phosphorylation of p38(MAPK), up-regulated expression of p21(CIP1/WAF1), and inhibited phosphorylation of Rb. SB203580 restrained exogenous IGFBP7-induced regulation of p21(CIP1/WAF1) and p-Rb in MDA-MB-453 cells. In conclusion, the present study suggests that exogenous IGFBP7 could activate the p38(MAPK) signaling pathway, upregulate p21(CIP1/WAF1) expression, inhibit phosphorylation of Rb, and finally induce G0/G1 arrest in MDA-MB-453 cells.

Cigarette smoke exposure reveals a novel role for the MEK/ERK1/2 MAPK pathway in regulation of CFTR

PubMed Central

Xu, Xiaohua; Balsiger, Robert; Tyrrell, Jean; Boyaka, Prosper N.; Tarran, Robert; Cormet-Boyaka, Estelle

2015-01-01

Background CFTR plays a key role in maintenance of lung fluid homeostasis. Cigarette smoke decreases CFTR expression in the lung but neither the mechanisms leading to CFTR loss, nor potential ways to prevent its loss have been identified to date. Methods The molecular mechanisms leading to down-regulation of CFTR by cigarette smoke were determined using pharmacologic inhibitors and silencing RNAs. Results Using human bronchial epithelial cells, here we show that cigarette smoke induces degradation of CFTR that is attenuated by the lysosomal inhibitors, but not proteasome inhibitors. Cigarette smoke can activate multiple signaling pathways in airway epithelial cells, including the MEK/Erk1/2 MAPK pathway regulating cell survival. Interestingly, pharmacological inhibition of the MEK/Erk1/2 MAPK pathway prevented the loss of plasma membrane CFTR upon cigarette smoke exposure. Similarly, decreased expression of Erk1/2 using silencing RNAs prevented the suppression of CFTR protein by cigarette smoke. Conversely, specific inhibitors of the JNK or p38 MAPK pathways had no effect on CFTR decrease after cigarette smoke exposure. In addition, inhibition of the MEK/Erk1/2 MAPK pathway prevented the reduction of the airway surface liquid observed upon cigarette smoke exposure of primary human airway epithelial cells. Finally, addition of the antioxidant NAC inhibited activation of Erk1/2 by cigarette smoke and precluded the cigarette smoke-induced decrease of CFTR. Conclusions These results show that the MEK/Erk1/2 MAPK pathway regulates plasma membrane CFTR in human airway cells. General Significance The MEK/Erk1/2 MAPK pathway should be considered as a target for strategies to maintain/restore CFTR expression in the lung of smokers. PMID:25697727

Neuroprotective Effects of a Novel Single Compound 1-Methoxyoctadecan-1-ol Isolated from Uncaria sinensis in Primary Cortical Neurons and a Photothrombotic Ischemia Model

PubMed Central

Kim, Ha Neui; Kim, Yu Ri; Hong, Jin Woo; Bae, Dong Won; Park, Se Jin; Shin, Hwa Kyoung; Choi, Byung Tae

2014-01-01

We identified a novel neuroprotective compound, 1-methoxyoctadecan-1-ol, from Uncaria sinensis (Oliv.) Havil and investigated its effects and mechanisms in primary cortical neurons and in a photothrombotic ischemic model. In primary rat cortical neurons against glutamate-induced neurotoxicity, pretreatment with 1-methoxyoctadecan-1-ol resulted in significantly reduced neuronal death in a dose-dependent manner. In addition, treatment with 1-methoxyoctadecan-1-ol resulted in decreased neuronal apoptotic death, as assessed by nuclear morphological approaches. To clarify the neuroprotective mechanism of 1-methoxyoctadecan-1-ol, we explored the downstream signaling pathways of N-methyl-D-aspartate receptor (NMDAR) with calpain activation. Treatment with glutamate leads to early activation of NMDAR, which in turn leads to calpain-mediated cleavage of striatal-enriched protein tyrosine phosphatase (STEP) and subsequent activation of p38 mitogen activated protein kinase (MAPK). However, pretreatment with 1-methoxyoctadecan-1-ol resulted in significantly attenuated activation of GluN2B-NMDAR and a decrease in calpain-mediated STEP cleavage, leading to subsequent attenuation of p38 MAPK activation. We confirmed the critical role of p38 MAPK in neuroprotective effects of 1-methoxyoctadecan-1-ol using specific inhibitor SB203580. In the photothrombotic ischemic injury in mice, treatment with 1-methoxyoctadecan-1-ol resulted in significantly reduced infarct volume, edema size, and improved neurological function. 1-methoxyoctadecan-1-ol effectively prevents cerebral ischemic damage through down-regulation of calpain-mediated STEP cleavage and activation of p38 MAPK. These results suggest that 1-methoxyoctadecan-1-ol showed neuroprotective effects through down-regulation of calpain-mediated STEP cleavage with activation of GluN2B-NMDAR, and subsequent alleviation of p38 MAPK activation. In addition, 1-methoxyoctadecan-1-ol might be a useful therapeutic agent for brain disorder such as ischemic stroke. PMID:24416390

Blockade of p38 Mitogen-Activated Protein Kinase Inhibits Murine Sclerodermatous Chronic Graft-versus-Host Disease.

PubMed

Matsushita, Takashi; Date, Mutsumi; Kano, Miyu; Mizumaki, Kie; Tennichi, Momoko; Kobayashi, Tadahiro; Hamaguchi, Yasuhito; Hasegawa, Minoru; Fujimoto, Manabu; Takehara, Kazuhiko

2017-04-01

Bone marrow transplantation (BMT) of B10.D2 mice into sublethally irradiated BALB/c mice across minor histocompatibility loci is a well-established animal model for human sclerodermatous chronic graft-versus-host disease (Scl-cGVHD) and systemic sclerosis (SSc). The p38 mitogen-activated protein kinase (MAPK) pathway is a key regulator of inflammation and cytokine production. Furthermore, the activation of p38 MAPK plays an important role in collagen production in SSc. We investigated the effects of p38 MAPK inhibitor, VX-702, on Scl-cGVHD mice. VX-702 was orally administered to Scl-cGVHD mice from day 7 to 35 after BMT. We compared skin fibrosis of Scl-cGVHD mice between the VX-702-treated group and control group. Allogeneic BMT increased the phosphorylation of p38 MAPK in the skin. The administration of VX-702 attenuated the skin fibrosis of Scl-cGVHD compared to the control mice. Immunohistochemical staining showed that VX-702 suppressed the infiltration of CD4 + T cells, CD8 + T cells, and CD11b + cells into the dermis of Scl-cGVHD mice compared to the control mice. VX-702 attenuated the mRNA expression of extracellular matrix and fibrogenic cytokines, such as IL-6 and IL-13, in the skin of Scl-cGVHD mice. In addition, VX-702 directly inhibited collagen production from fibroblasts in vitro. VX-702 was shown to be a promising candidate for use in treating patients with Scl-cGVHD and SSc. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Melatonin prevents secondary intra-abdominal hypertension in rats possibly through inhibition of the p38 MAPK pathway.

PubMed

Chang, Mingtao; Li, Yang; Liu, Dong; Zhang, Lianyang; Zhang, Hongguang; Tang, Hao; Zhang, Huayu

2016-08-01

Exogenous administration of melatonin has been demonstrated to down-regulate inflammatory responses and attenuate organ damage in various models. However, the salutary effect of melatonin against secondary intra-abdominal hypertension (IAH) remains unclear. This study sought to test the influence of melatonin on secondary IAH in a pathophysiological rat model and the underlying mechanisms involved. Before resuscitation, male rats underwent a combination of induced portal hypertension, applying an abdominal restraint device, and hemorrhaging to mean arterial pressure (MAP) of 40mmHg for 2h. After blood reinfusion, the rats were treated with lactated Ringer solution (LR) (30mL/h), melatonin (50mg/kg) +LR, and SB-203580 (10μmol/kg)+LR. LR was continuously infused for 6h. MAP, the inferior vena cava pressure and urine output were monitored. Histopathological examination, immunofluorescence of tight junction proteins, and transmission electron microscopy were administered. Intestinal permeability, myeloperoxidase activity, malondialdehyde, glutathione peroxidase, and levels of TNF-a, IL-2, and IL-6, were assessed. The expression of extracellular signal-regulated kinase, p38, c-Jun NH2-terminal kinase, translocation of nuclear factor kappa B subunit, signal transducers and activators of transcription and tight junction proteins were detected by Western blot. We found that melatonin inhibited the inflammatory responses, decreased expression of p38 MAPK, attenuated intestinal injury, and prevented secondary IAH. Moreover, administration of SB203580 abolished the increase in p38 MAPK and also attenuated intestinal injury. These data indicate that melatonin exerts a protective effect in intestine in secondary IAH primarily by attenuating the inflammatory responses which are in part attributable to p38 MAPK inhibition. Copyright © 2016 Elsevier Inc. All rights reserved.

Primate Torpor: Regulation of Stress-activated Protein Kinases During Daily Torpor in the Gray Mouse Lemur, Microcebus murinus.

PubMed

Biggar, Kyle K; Wu, Cheng-Wei; Tessier, Shannon N; Zhang, Jing; Pifferi, Fabien; Perret, Martine; Storey, Kenneth B

2015-04-01

Very few selected species of primates are known to be capable of entering torpor. This exciting discovery means that the ability to enter a natural state of dormancy is an ancestral trait among primates and, in phylogenetic terms, is very close to the human lineage. To explore the regulatory mechanisms that underlie primate torpor, we analyzed signal transduction cascades to discover those involved in coordinating tissue responses during torpor. The responses of mitogen-activated protein kinase (MAPK) family members to primate torpor were compared in six organs of control (aroused) versus torpid gray mouse lemurs, Microcebus murinus. The proteins examined include extracellular signal-regulated kinases (ERKs), c-jun NH2-terminal kinases (JNKs), MAPK kinase (MEK), and p38, in addition to stress-related proteins p53 and heat shock protein 27 (HSP27). The activation of specific MAPK signal transduction pathways may provide a mechanism to regulate the expression of torpor-responsive genes or the regulation of selected downstream cellular processes. In response to torpor, each MAPK subfamily responded differently during torpor and each showed organ-specific patterns of response. For example, skeletal muscle displayed elevated relative phosphorylation of ERK1/2 during torpor. Interestingly, adipose tissues showed the highest degree of MAPK activation. Brown adipose tissue displayed an activation of ERK1/2 and p38, whereas white adipose tissue showed activation of ERK1/2, p38, MEK, and JNK during torpor. Importantly, both adipose tissues possess specialized functions that are critical for torpor, with brown adipose required for non-shivering thermogenesis and white adipose utilized as the primary source of lipid fuel for torpor. Overall, these data indicate crucial roles of MAPKs in the regulation of primate organs during torpor. Copyright © 2015. Production and hosting by Elsevier Ltd.

Regulation of human glioblastoma cell death by combined treatment of cannabidiol, γ-radiation and small molecule inhibitors of cell signaling pathways

PubMed Central

Ivanov, Vladimir N.; Wu, Jinhua; Hei, Tom K.

2017-01-01

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. The challenging problem in cancer treatment is to find a way to upregulate radiosensitivity of GBM while protecting neurons and neural stem/progenitor cells in the brain. The goal of the present study was upregulation of the cytotoxic effect of γ-irradiation in GBM by non-psychotropic and non-toxic cannabinoid, cannabidiol (CBD). We emphasized three main aspects of signaling mechanisms induced by CBD treatment (alone or in combination with γ-irradiation) in human GBM that govern cell death: 1) CBD significantly upregulated the active (phosphorylated) JNK1/2 and MAPK p38 levels with the subsequent downregulation of the active phospho-ERK1/2 and phospho-AKT1 levels. MAPK p38 was one of the main drivers of CBD-induced cell death, while death levels after combined treatment of CBD and radiation were dependent on both MAPK p38 and JNK. Both MAPK p38 and JNK regulate the endogenous TRAIL expression. 2) NF-κB p65-P(Ser536) was not the main target of CBD treatment and this transcription factor was found at high levels in CBD-treated GBM cells. Additional suppression of p65-P(Ser536) levels using specific small molecule inhibitors significantly increased CBD-induced apoptosis. 3) CBD treatment substantially upregulated TNF/TNFR1 and TRAIL/TRAIL-R2 signaling by modulation of both ligand and receptor levels followed by apoptosis. Our results demonstrate that radiation-induced death in GBM could be enhanced by CBD-mediated signaling in concert with its marginal effects for neural stem/progenitor cells and astrocytes. It will allow selecting efficient targets for sensitization of GBM and overcoming cancer therapy-induced severe adverse sequelae. PMID:29088769

Macrophages produce IL-33 by activating MAPK signaling pathway during RSV infection.

PubMed

Qi, Feifei; Bai, Song; Wang, Dandan; Xu, Lei; Hu, Haiyan; Zeng, Sheng; Chai, Ruonan; Liu, Beixing

2017-07-01

It has been reported that RSV infection can enhance IL-33 production in lung macrophages. However, little is known about specific signaling pathways for activation of macrophages during RSV infection. In the present study, by using real-time RT-PCR as well as western blot assay, it became clear that RSV infection can enhance not only the expression of mRNAs for MAPK molecules (including p38, JNK1/2, and ERK1/2), but also the levels of MAPK proteins in lung macrophages as well as RAW264.7 cells. Furthermore, infection with RSV resulted in an increased level of phosphorylated MAPK proteins in RAW264.7 cells, suggesting that MAPK signaling pathway may participate in the process of RSV-induced IL-33 secretion by macrophages. In fact, the elevated production of IL-33 in RAW264.7 was attenuated significantly by pretreatment of the cells with special MAPK inhibitor before RSV infection, further confirming the function of MAPKs pathway in RSV-induced IL-33 production in macrophages. In contrast, the expression of NF-κB mRNA as well as the production of NF-κB protein in lung macrophages and RAW264.7 cells was not enhanced markedly after RSV infection. Moreover, RSV infection failed to induce the phosphorylation of NF-κB in RAW264.7 cells, suggesting that NF-κB signaling pathway may be not involved in RSV-induced IL-33 production in macrophages. Conclusion, these results indicate that RSV-induced production of IL-33 in macrophages is dependent on the activation of MAPK signaling pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

Role of Spm-Cer-S1P signalling pathway in MMP-2 mediated U46619-induced proliferation of pulmonary artery smooth muscle cells: protective role of epigallocatechin-3-gallate.

PubMed

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

2015-10-01

During remodelling of pulmonary artery, marked proliferation of pulmonary artery smooth muscle cells (PASMCs) occurs, which contributes to pulmonary hypertension. Thromboxane A2 (TxA2) has been shown to produce pulmonary hypertension. The present study investigates the inhibitory effect of epigallocatechin-3-gallate (EGCG) on the TxA2 mimetic, U46619-induced proliferation of PASMCs. U46619 at a concentration of 10 nM induces maximum proliferation of bovine PASMCs. Both pharmacological and genetic inhibitors of p(38)MAPK, NF-κB and MMP-2 significantly inhibit U46619-induced cell proliferation. EGCG markedly abrogate U46619-induced p(38)MAPK phosphorylation, NF-κB activation, proMMP-2 expression and activation, and also the cell proliferation. U46619 causes an increase in the activation of sphingomyelinase (SMase) and sphingosine kinase (SPHK) and also increase sphingosine 1 phosphate (S1P) level. U46619 also induces phosphorylation of ERK1/2, which phosphorylates SPHK leading to an increase in S1P level. Both pharmacological and genetic inhibitors of SMase and SPHK markedly inhibit U46619-induced cell proliferation. Additionally, pharmacological and genetic inhibitors of MMP-2 markedly abrogate U46619-induced SMase activity and S1P level. EGCG markedly inhibit U46619-induced SMase activity, ERK1/2 and SPHK phosphorylation and S1P level in the cells. Overall, Sphingomyeline-Ceramide-Sphingosine-1-phosphate (Spm-Cer-S1P) signalling axis plays an important role in MMP-2 mediated U46619-induced proliferation of PASMCs. Importantly, EGCG inhibits U46619 induced increase in MMP-2 activation by modulating p(38)MAPK-NFκB pathway and subsequently prevents the cell proliferation. Copyright © 2015 John Wiley & Sons, Ltd.

Proton induces apoptosis of hypoxic tumor cells by the p53-dependent and p38/JNK MAPK signaling pathways.

PubMed

Lee, Kheun Byeol; Kim, Kye-Ryung; Huh, Tae-Lin; Lee, You Mie

2008-12-01

Tumor hypoxia is a main obstacle for radiation therapy. To investigate whether exposure to a proton beam can overcome radioresistance in hypoxic tumor cells, three kinds of cancer cells, Lewis lung carcinoma (LLC) cells, hepatoma HepG2 and Molt-4 leukemia cells, were treated with a proton beam (35 MeV, 1, 2, 5, 10 Gy) in the presence or absence of hypoxia. Cell death rates were determined 72 h after irradiation. Hypoxic cells exposed to the proton beam underwent a typical apoptotic program, showing condensed nuclei, fragmented DNA ladders, and poly-ADP-ribose polymerase (PARP) cleavage. Fluorescence-activated cell sorter analysis revealed a significant increase in Annexin-V-positive cells. Cells treated with the proton beam and hypoxia displayed increased expression of p53, p21 and Bax, but decreased levels of phospho-Rb, Bcl-2 and XIAP, as well as activated caspase-9 and -3. The proton beam with hypoxia induced cell death in wild-type HCT116 cells, but not in a p53 knockout cell line, demonstrating a requirement for p53. As reactive oxygen species (ROS) were also significantly increased, apoptosis could also be abolished by treatment with the anti-oxidant N-acetyl cysteine (NAC). P38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) were activated by the treatment, and their respective DN mutants restored the cell death induced by either proton therapy alone or with hypoxia. In conclusion, proton beam treatment did not differently regulate cancer cell apoptosis either in normoxic or hypoxic conditions via a p53-dependent mechanism and by the activation of p38/JNK MAPK pathways through ROS.

Oestrogen exerts anti-inflammation via p38 MAPK/NF-κB cascade in adipocytes.

PubMed

Mu, Pan-Wei; Jiang, Ping; Wang, Man-Man; Chen, Yan-Ming; Zheng, Shu-Hui; Tan, Zhi; Jiang, Wei; Zeng, Long-Yi; Wang, Ting-Huai

Oestrogen has anti-inflammatory property in obesity. However, the mechanism is still not defined. To investigate the effect of oestrogen on LPS-induced monocyte chemoattractant protein-1 (MCP-1) production in adipocytes. Lipopolysaccharides (LPS) was used to imitate inflammatory responses and monocyte chemotactic protein-1 (MCP-1) was selected as an inflammatory marker to observe. 17β-Estradiol (E 2 ), SB203580 (SB), pyrrolidine dithiocarbamate (PDTC), pertussis toxin (PTX), wortmannin (WM), p65 siRNA and p38 MAPK siRNA were pre-treated respectively or together in LPS-induced MCP-1. Then p38 MAPK and NF-κB cascade were silenced successively to observe the change of each other. Lastly, oestrogen receptor (ER) α agonist, ERβ agonist and ER antagonist were utilised. LPS-induced MCP-1 largely impaired by pre-treatment with E 2 , SB, PDTC or silencing NF-κB subunit. E 2 inhibited LPS-induced MCP-1 in a time- and dose-dependent manner, which was related to the suppression of p65 translocation to nucleus. Furthermore, LPS rapidly activated p38 MAPK, while E 2 markedly inhibited this activation. It markedly attenuated LPS-stimulated p65 translocation to nucleus and MCP-1 production by transfecting with p38 MAPK siRNA or using p38 MAPK inhibitor. The oestrogen's inhibitory effect was mimicked by the ERα agonist, but not by the ERβ agonist. The inhibition of E 2 on p38 MAPK phosphorylation was prevented by ER antagonist. E 2 inhibits LPS-stimulated MCP-1 in adipocytes. This effect is related to the inhibition of p38 MAPK/NF-κB cascade, and ERα appears to be the dominant ER subtype in these events. Copyright © 2016 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Interleukin-1 Receptor Activation by Systemic Lipopolysaccharide Induces Behavioral Despair Linked to MAPK Regulation of CNS Serotonin Transporters

PubMed Central

Zhu, Chong-Bin; Lindler, Kathryn M; Owens, Anthony W; Daws, Lynette C; Blakely, Randy D; Hewlett, William A

2010-01-01

Serotonin (5-hydroxytryptamine, 5-HT) has long been implicated in regulation of mood. Medications that block the neuronal 5-HT transporter (SERT) are used as major pharmacological treatment for mood disorders. Conversely, stimuli that enhance SERT activity might be predicted to diminish synaptic 5-HT availability and increase the risk for 5-HT-related CNS disorders. We have shown that the inflammatory cytokines enhance brain SERT activity in cultured serotonergic cells and nerve terminal preparations in vitro. In this study, we establish that intraperitoneal injection of the cytokine-inducer lipopolysaccharide (LPS) stimulates brain SERT activity, acting at doses below those required to induce overt motor suppression. SERT stimulation by LPS is paralleled by increased immobility in both the tail suspension test (TST) and the forced swim test (FST); antidepressant-sensitive alterations are thought to model aspects of behavioral despair. Both the stimulation of SERT activity and induced immobility are absent when LPS is administered to interleukin-1 receptor (IL-1R)-deficient mice and in the presence of SB203580, an inhibitor of IL-1R-stimulated p38 MAPK. Moreover, the ability of LPS to enhance immobility in TST is lost in SERT knockout mice. These findings reveal an ability of peripheral inflammatory stimuli to enhance brain SERT activity through IL-1R and p38 MAPK pathways in vivo and identify a requirement for SERT expression in immune-system-modulated despair behaviors. Our studies identify IL-1R- and p38 MAPK-dependent regulation of SERT as one of the mechanisms by which environmentally driven immune system activation can trigger despair-like behavior in an animal model, encouraging future analysis of the pathway for risk factors in neuropsychiatric disorders. PMID:20827273

Substance P Receptor Antagonist Suppresses Inflammatory Cytokine Expression in Human Disc Cells.

PubMed

Kepler, Christopher K; Markova, Dessislava Z; Koerner, John D; Mendelis, Joseph; Chen, Chiu-Ming; Vaccaro, Alexander R; Risbud, Makarand V; Albert, Todd J; Anderson, D Greg

2015-08-15

Laboratory study. To evaluate whether blockade of the Substance P (SP) NK1R attenuates its proinflammatory effect on human intervertebral disc cells (IVD), and to evaluate the signaling pathways associated with SP. SP and its receptors are expressed in human IVD cells, and cause upregulation of inflammatory mediators; however, the effects of blocking these receptors have not been studied in human IVD cells. Human annulus fibrosus (AF) and nucleus pulposus (NP) cells were expanded in monolayer, and then suspended in alginate beads. The alginate beads were treated with culture medium first containing a high affinity NK1R antagonist (L-760735) at different concentrations, and then with medium containing both NK1R antagonist and SP at 2 concentrations. Ribonucleic acid was isolated and transcribed into cDNA. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to evaluate expression of interleukin (IL)-1β, IL-6, and IL-8. Western blot analysis was performed to examine levels of the phosphorylated p38 mitogen-activated protein kinase (MAPK), extracellular signal regulated kinase 1/2 (ERK1/2) and nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB p65). The cells were pretreated with specific inhibitors of p38 (SB203580), ERK1/2 (PD98059), and p65 (SM7368) and then stimulated with SP. We detected expression of NK1R, neurokinin receptor 2 (NK2R), and neurokinin receptor 3 (NK3R) in AF and NP cells. Treatment of disc cells with the NK1R antagonist was able to suppress expression of IL-1β, IL-6, and IL-8 in a dose-dependent manner. SP stimulation increased phosphorylation of p38-MAPK and ERK1/2, but not of NFκB p65. This indicates that p38-MAPK and ERK1/2 control SP-induced cytokine expression independently from NF-kB p65. Inhibition of p38 and ERK1/2 activation reduced SP-induced IL-6 production in human disc cells. NK1R is responsible for the proinflammatory effect of SP on IVD cells and this effect can be blocked by preventing binding of SP to NK1R. This study shows for the first time that SP mediates signaling in disc cells through NK1R and that SP activates the proinflammatory p38-MAPK and ERK1/2 pathways. 4.

A low dose lipid infusion is sufficient to induce insulin resistance and a pro-inflammatory response in human subjects

PubMed Central

Lum, Helen; Alvarez, Andrea; Garduno-Garcia, Jose de Jesus; Daniel, Benjamin J.; Musi, Nicolas

2018-01-01

Objective The root cause behind the low-grade inflammatory state seen in insulin resistant (obesity and type 2 diabetes) states is unclear. Insulin resistant subjects have elevations in plasma free fatty acids (FFA), which are ligands for the pro-inflammatory toll-like receptor (TLR)4 pathway. We tested the hypothesis that an experimental elevation in plasma FFA (within physiological levels) in lean individuals would upregulate TLR4 and activate downstream pathways (e.g., MAPK) in circulating monocytes. Research design and methods Twelve lean, normal glucose-tolerant subjects received a low dose (30 ml/h) 48 h lipid or saline infusion on two different occasions. Monocyte TLR4 protein level, MAPK phosphorylation, and expression of genes in the TLR pathway were determined before and after each infusion. Results The lipid infusion significantly increased monocyte TLR4 protein and phosphorylation of JNK and p38 MAPK. Lipid-mediated increases in TLR4 and p38 phosphorylation directly correlated with reduced peripheral insulin sensitivity (M value). Lipid increased levels of multiple genes linked to inflammation, including several TLRs, CD180, MAP3K7, and CXCL10. Monocytes exposed in vivo to lipid infusion exhibited enhanced in vitro basal and LPS-stimulated IL-1β secretion. Conclusions In lean subjects, a small increase in plasma FFA (as seen in insulin resistant subjects) is sufficient to upregulate TLR4 and stimulate inflammatory pathways (MAPK) in monocytes. Moreover, lipids prime monocytes to endotoxin. We provide proof-of-concept data in humans indicating that the low-grade inflammatory state characteristic of obesity and type 2 diabetes could be caused (at least partially) by pro-inflammatory monocytes activated by excess lipids present in these individuals. PMID:29649324

A low dose lipid infusion is sufficient to induce insulin resistance and a pro-inflammatory response in human subjects.

PubMed

Liang, Hanyu; Lum, Helen; Alvarez, Andrea; Garduno-Garcia, Jose de Jesus; Daniel, Benjamin J; Musi, Nicolas

2018-01-01

The root cause behind the low-grade inflammatory state seen in insulin resistant (obesity and type 2 diabetes) states is unclear. Insulin resistant subjects have elevations in plasma free fatty acids (FFA), which are ligands for the pro-inflammatory toll-like receptor (TLR)4 pathway. We tested the hypothesis that an experimental elevation in plasma FFA (within physiological levels) in lean individuals would upregulate TLR4 and activate downstream pathways (e.g., MAPK) in circulating monocytes. Twelve lean, normal glucose-tolerant subjects received a low dose (30 ml/h) 48 h lipid or saline infusion on two different occasions. Monocyte TLR4 protein level, MAPK phosphorylation, and expression of genes in the TLR pathway were determined before and after each infusion. The lipid infusion significantly increased monocyte TLR4 protein and phosphorylation of JNK and p38 MAPK. Lipid-mediated increases in TLR4 and p38 phosphorylation directly correlated with reduced peripheral insulin sensitivity (M value). Lipid increased levels of multiple genes linked to inflammation, including several TLRs, CD180, MAP3K7, and CXCL10. Monocytes exposed in vivo to lipid infusion exhibited enhanced in vitro basal and LPS-stimulated IL-1β secretion. In lean subjects, a small increase in plasma FFA (as seen in insulin resistant subjects) is sufficient to upregulate TLR4 and stimulate inflammatory pathways (MAPK) in monocytes. Moreover, lipids prime monocytes to endotoxin. We provide proof-of-concept data in humans indicating that the low-grade inflammatory state characteristic of obesity and type 2 diabetes could be caused (at least partially) by pro-inflammatory monocytes activated by excess lipids present in these individuals.

Overactivation of Mitogen-Activated Protein Kinase and Suppression of Mitofusin-2 Expression Are Two Independent Events in High Mobility Group Box 1 Protein–Mediated T Cell Immune Dysfunction

PubMed Central

Tang, Lu-ming; Zhao, Guang-ju; Zhu, Xiao-mei; Dong, Ning; Yu, Yan

2013-01-01

High mobility group box 1 protein (HMGB1), a critical proinflammatory cytokine, has recently been identified to be an immunostimulatory signal involved in sepsis-related immune dysfunction when released extracellularly, but the potential mechanism involved remains elusive. Here, we showed that the treatment with HMGB1 in vitro inhibited T lymphocyte immune response and expression of mitofusin-2 (Mfn-2; a member of the mitofusin family) in a dose- and time-dependent manner. Upregulation of Mfn-2 expression attenuated the suppressive effect of HMGB1 on T cell immune function. The phosphorylation of both extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) was markedly upregulated by treating with high amount of HMGB1, while pretreatment with ERK1/2 and p38 MAPK-specific inhibitors (U0126 and SB203580) could attenuate suppression of T cell immune function and nuclear factor of activated T cell (NFAT) activation induced by HMGB1, respectively. HMGB1-induced activity of ERK1/2 and p38 was not fully inhibited in the presence of U0126 or SB203580. Interestingly, overexpression of Mfn-2 had no marked effect on HMGB1-mediated activation of MAPK, but could attenuate the suppressive effect of HMGB1 on the activity of NFAT. Thus, the mechanisms involved in HMGB1-induced T cell immune dysfunction in vitro at least partly include suppression of Mfn-2 expression, overactivation of ERK1/2, p38 MAPK, and intervention of NFAT activation, while the protective effect of Mfn-2 on T cell immune dysfunction induced by HMGB1 is dependent on other signaling pathway associated with NFAT, but not MAPK. Taken together, we conclude that overactivation of MAPK and suppression of Mfn-2 expression are two independent events in HMGB1-mediated T cell immune dysfunction. PMID:23697559

ERK and p38 MAPK-Activated Protein Kinases: a Family of Protein Kinases with Diverse Biological Functions

PubMed Central

Roux, Philippe P.; Blenis, John

2004-01-01

Conserved signaling pathways that activate the mitogen-activated protein kinases (MAPKs) are involved in relaying extracellular stimulations to intracellular responses. The MAPKs coordinately regulate cell proliferation, differentiation, motility, and survival, which are functions also known to be mediated by members of a growing family of MAPK-activated protein kinases (MKs; formerly known as MAPKAP kinases). The MKs are related serine/threonine kinases that respond to mitogenic and stress stimuli through proline-directed phosphorylation and activation of the kinase domain by extracellular signal-regulated kinases 1 and 2 and p38 MAPKs. There are currently 11 vertebrate MKs in five subfamilies based on primary sequence homology: the ribosomal S6 kinases, the mitogen- and stress-activated kinases, the MAPK-interacting kinases, MAPK-activated protein kinases 2 and 3, and MK5. In the last 5 years, several MK substrates have been identified, which has helped tremendously to identify the biological role of the members of this family. Together with data from the study of MK-knockout mice, the identities of the MK substrates indicate that they play important roles in diverse biological processes, including mRNA translation, cell proliferation and survival, and the nuclear genomic response to mitogens and cellular stresses. In this article, we review the existing data on the MKs and discuss their physiological functions based on recent discoveries. PMID:15187187

6-Gingerol protects intestinal barrier from ischemia/reperfusion-induced damage via inhibition of p38 MAPK to NF-κB signalling.

PubMed

Li, Yanli; Xu, Bin; Xu, Ming; Chen, Dapeng; Xiong, Yongjian; Lian, Mengqiao; Sun, Yuchao; Tang, Zeyao; Wang, Li; Jiang, Chunling; Lin, Yuan

2017-05-01

Intestinal ischemia reperfusion (I/R) injury caused by severe trauma, intestinal obstruction, and operation is one of the tough challenges in clinic. 6-Gingerol (6G), a main active ingredient of ginger, is found to have anti-microbial, anti-inflammatory, anti-oxidative, and anti-cancer activities. The present study was designed to characterize the potential protective effects of 6G on rat intestinal I/R injury and reveal the correlated mechanisms. Rat intestinal I/R model was established with clamping the superior mesenteric artery (SMA) and 6G was intragastrically administered for three consecutive days before I/R injury. Caco-2 and IEC-6 cells were incubated under hypoxia/reoxygenation (H/R) conditions to simulate I/R injury in vitro. The results showed that 6G significantly alleviated intestinal injury in I/R injured rats by reducing the generation of oxidative stress and inhibiting p38 MAPK signaling pathway. 6G significantly reduced MDA level and increased the levels of SOD, GSH, and GSH-Px in I/R injured intestinal tissues. 6G significantly decreased the production of proinflammatory cytokines including TNF-α, IL-1β, and IL-6, and inhibited the expression of inflammatory mediators iNOS/NO in I/R injured intestinal tissues. The impaired intestinal barrier function was restored by using 6G in I/R injured rats and in both Caco-2 and IEC-6 cells characterized by inhibiting p38 MAPK phosphorylation, nuclear translocation of NF-κB, and expression of myosin light chain kinase (MLCK) protein. 6G also reduced the generation of reactive oxygen species (ROS) in both Caco-2 and IEC-6 cells. In vitro transfection of p38 MAPK siRNA mitigated the impact of 6G on NF-κB and MLCK expression, and the results further corroborated the protective effects of 6G on intestinal I/R injury by repressing p38 MAPK signaling. In conclusion, the present study suggests that 6G exerts protective effects against I/R-induced intestinal mucosa injury by inhibiting the formation of ROS and p38 MAPK activation, providing novel insights into the mechanisms of this therapeutic candidate for the treatment of intestinal injury. Copyright © 2017 Elsevier Ltd. All rights reserved.

Role of androgen receptor on cyclic mechanical stretch-regulated proliferation of C2C12 myoblasts and its upstream signals: IGF-1-mediated PI3K/Akt and MAPKs pathways.

PubMed

Ma, Yiming; Fu, Shaoting; Lu, Lin; Wang, Xiaohui

2017-07-15

To detect the effects of androgen receptor (AR) on cyclic mechanical stretch-modulated proliferation of C2C12 myoblasts and its pathways: roles of IGF-1, PI3K and MAPK. C2C12 were randomly divided into five groups: un-stretched control, six or 8 h of fifteen percent stretch, and six or 8 h of twenty percent stretch. Cyclic mechanical stretch of C2C12 were completed using a computer-controlled FlexCell Strain Unit. Cell proliferation and IGF-1 concentration in medium were detected by CCK8 and ELISA, respectively. Expressions of AR and IGF-1R, and expressions and activities of PI3K, p38 and ERK1/2 in stretched C2C12 cells were determined by Western blot. ①The proliferation of C2C12 cells, IGF-1 concentration in medium, expressions of AR and IGF-1R, and activities of PI3K, p38 and ERK1/2 were increased by 6 h of fifteen percent stretch, while decreased by twenty percent stretch for six or 8 h ②The fifteen percent stretch-increased proliferation of C2C12 cells was reversed by AR inhibitor, Flutamide. ③The increases of AR expression, activities of PI3K, p38 and ERK1/2 resulted from fifteen percent stretch were attenuated by IGF-1 neutralizing antibody, while twenty percent stretch-induced decreases of the above indicators were enhanced by recombinant IGF-1. ④Specific inhibitors of p38, ERK1/2 and PI3K all decreased the expression of AR in fifteen percent and twenty percent of stretched C2C12 cells. Cyclic mechanical stretch modulated the proliferation of C2C12 cells, which may be attributed to the alterations of AR via IGF-1-PI3K/Akt and IGF-1-MAPK (p38, ERK1/2) pathways in C2C12 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Time course of the MAPK and PI3-kinase response within 24 h of skeletal muscle overload

NASA Technical Reports Server (NTRS)

Carlson, C. J.; Fan, Z.; Gordon, S. E.; Booth, F. W.

2001-01-01

Knowledge of the molecular mechanisms by which skeletal muscle hypertrophies in response to increased mechanical loading may lead to the discovery of novel treatment strategies for muscle wasting and frailty. To gain insight into potential early signaling mechanisms associated with skeletal muscle hypertrophy, the temporal pattern of mitogen-activated protein kinase (MAPK) phosphorylation and phosphatidylinositol 3-kinase (PI3-kinase) activity during the first 24 h of muscle overload was determined in the rat slow-twitch soleus and fast-twitch plantaris muscles after ablation of the gastrocnemius muscle. p38alpha MAPK phosphorylation was elevated for the entire 24-h overload period in both muscles. In contrast, Erk 2 and p54 JNK phosphorylation were transiently increased by overload, returning to the levels of sham-operated controls by 24 h. PI3-kinase activity was increased by muscle overload only at 12 h of overload and only in the plantaris muscle. In summary, sustained elevation of p38alpha MAPK phosphorylation occurred early in response to muscle overload, identifying this pathway as a potential candidate for mediating early hypertrophic signals in response to skeletal muscle overload.

Cardiac fibrosis and dysfunction in experimental diabetic cardiomyopathy are ameliorated by alpha-lipoic acid.

PubMed

Li, Chun-jun; Lv, Lin; Li, Hui; Yu, De-min

2012-06-19

Alpha-lipoic acid (ALA), a naturally occurring compound, exerts powerful protective effects in various cardiovascular disease models. However, its role in protecting against diabetic cardiomyopathy (DCM) has not been elucidated. In this study, we have investigated the effects of ALA on cardiac dysfunction, mitochondrial oxidative stress (MOS), extracellular matrix (ECM) remodeling and interrelated signaling pathways in a diabetic rat model. Diabetes was induced in rats by I.V. injection of streptozotocin (STZ) at 45 mg/kg. The animals were randomly divided into 4 groups: normal groups with or without ALA treatment, and diabetes groups with or without ALA treatment. All studies were carried out 11 weeks after induction of diabetes. Cardiac catheterization was performed to evaluate cardiac function. Mitochondrial oxidative biochemical parameters were measured by spectophotometeric assays. Extracellular matrix content (total collagen, type I and III collagen) was assessed by staining with Sirius Red. Gelatinolytic activity of Pro- and active matrix metalloproteinase-2 (MMP-2) levels were analyzed by a zymogram. Cardiac fibroblasts differentiation to myofibroblasts was evaluated by Western blot measuring smooth muscle actin (α-SMA) and transforming growth factor-β (TGF-β). Key components of underlying signaling pathways including the phosphorylation of c-Jun N-terminal kinase (JNK), p38 MAPK and ERK were also assayed by Western blot. DCM was successfully induced by the injection of STZ as evidenced by abnormal heart mass and cardiac function, as well as the imbalance of ECM homeostasis. After administration of ALA, left ventricular dysfunction greatly improved; interstitial fibrosis also notably ameliorated indicated by decreased collagen deposition, ECM synthesis as well as enhanced ECM degradation. To further assess the underlying mechanism of improved DCM by ALA, redox status and cardiac remodeling associated signaling pathway components were evaluated. It was shown that redox homeostasis was disturbed and MAPK signaling pathway components activated in STZ-induced DCM animals. While ALA treatment favorably shifted redox homeostasis and suppressed JNK and p38 MAPK activation. These results, coupled with the excellent safety and tolerability profile of ALA in humans, demonstrate that ALA may have therapeutic potential in the treatment of DCM by attenuating MOS, ECM remodeling and JNK, p38 MAPK activation.

The integrity of PRRSV nucleocapsid protein is necessary for up-regulation of optimal interleukin-10 through NF-κB and p38 MAPK pathways in porcine alveolar macrophages.

PubMed

Yu, Jiang; Liu, Yanyan; Zhang, Yuyu; Zhu, Xiwang; Ren, Sufang; Guo, Lihui; Liu, Xing; Sun, Wenbo; Chen, Zhi; Cong, Xiaoyan; Chen, Lei; Shi, Jianli; Du, Yijun; Li, Jun; Wu, Jiaqiang; Wang, Jinbao

2017-08-01

Porcine reproductive and respiratory syndrome (PRRS), a highly contagious disease, has been constantly causing huge economic losses all over the world. PRRS virus (PRRSV) infection results in immunosuppression and IL-10 up-regulation. The relationship between them is still in dispute. Previous studies demonstrated the protein of PRRSV nucleocapsid (N) protein is able to up-regulate IL-10, yet the underlying molecular mechanisms remain unknown. In this study, the expression kinetics of IL-10 up-regulation induced by PRRSV N protein were analyzed in immortalized porcine alveolar macrophages (PAMs). N protein induced IL-10 expression in a time- and dose-dependent manner. Inhibition experiments of signaling pathways suggested NF-κB and p38 MAPK pathways are both involved in N protein-induced IL-10 up-regulation. Besides, the integrity of N protein is essential for significant IL-10 up-regulation. This research is beneficial for further understanding of the interplay between PRRSV and host immune system. Copyright © 2017. Published by Elsevier Ltd.

Cpg-ODN, a TLR9 Agonist, Aggravates Myocardial Ischemia/Reperfusion Injury by Activation of TLR9-P38 MAPK Signaling.

PubMed

Xie, Liang; He, Songqing; Kong, Na; Zhu, Ying; Tang, Yi; Li, Jianhua; Liu, Zhengbing; Liu, Jing; Gong, Jianbin

2018-06-19

Toll-like receptors (TLRs) have been implicated in myocardial ischemia/ reperfusion (I/R) injury. We examined the effect of CpG-oligodeoxynucleotide (ODN) on myocardial I/R injury. Male Sprague-Dawley rats were treated with either CpG-ODN or control ODN 1 h prior to myocardial ischemia (30 min) followed by reperfusion. Rats treated with phosphate-buffered saline (PBS) served as I/R controls (n = 8/group). Infarct size was determined by 2,3,5-triphenyltetrazolium chloride and Evans blue straining. Cardiac function was examined by echocardiography before and up to 14 days after myocardial I/R. CpG-ODN administration significantly increased infarct size and reduced cardiac function and survival rate after myocardial I/R, compared to the PBS-treated I/R group. Control-ODN did not alter I/R-induced myocardial infarct size, cardiac dysfunction, and survival rate. Additionally, CpG-ODN promoted I/R-induced myocardial apoptosis and cleaved caspase-3 levels in the myocardium. CpG-ODN increased TLR9 activation and p38 phosphorylation in the myocardium. In vitro data also suggested that CpG-ODN treatment induced TLR9 activation and p38 phosphorylation. Importantly, p38 mitogen-activated protein kinase (MAPK) inhibition abolished CpG-ODN-induced cardiac injury. CpG-ODN, the TLR9 ligand, accelerates myocardial I/R injury. The mechanisms involve activation of the TLR9-p38 MAPK signaling pathway. © 2018 The Author(s). Published by S. Karger AG, Basel.

Possible role of ginsenoside Rb1 in skin wound healing via regulating senescent skin dermal fibroblast.

PubMed

Hou, Jingang; Kim, Sunchang

2018-05-05

Cellular senescence suppresses cancer by inducing irreversible cell growth arrest. Nevertheless, senescent cells is proposed as causal link with aging and aging-related pathologies. The physiological beneficial functions of senescent cells are still of paucity. Here we show that senescent human dermal fibroblast accelerates keratinocytes scratch wound healing and stimulates differentiation of fibroblast. Using oxidative stress (100 μM H 2 O 2 exposure for 1 h) induction, we successfully triggered fibroblast senescence and developed senescence associated secretory phenotype (SASP). The induction of SASP was regulated by p38MAPK/MSK2/NF-κB pathway. Interestingly, inhibition of p38MAPK activation only partially suppressed SASP. However, SASP was significantly inhibited by SB747651A, a specific MSK inhibitor. Additionally, we demonstrate that SASP stimulates migration of keratinocytes and myofibroblast transition of fibroblast, through fold-increased secretion of growth factors, platelet-derived growth factor AA (PDGF-AA) and AB (PDGF-AB), transforming growth factor beta 1 (TGF-β1) and beta 2 (TGF-β2), vascular endothelial growth factor A (VEGF-A) and D (VEGF-D), vascular endothelial growth factor receptor 2 (VEGFR2) and 3 (VEGFR3). Importantly, we also confirmed ginsenoside Rb1 promoted SASP-mediated healing process via p38MAPK/MSK2/NF-κB pathway. The results pointed to senescent fibroblast as a potential mechanism of wound healing control in human skin. Further, it provided a candidate targeted for wound therapy. Copyright © 2018 Elsevier Inc. All rights reserved.

Changes in mycelia growth, sporulation, and virulence of Phytophthora capsici when challenged by heavy metals (Cu2+, Cr2+ and Hg2+) under acid pH stress.

PubMed

Liu, Peiqing; Wei, Mengyao; Zhang, Jinzhu; Wang, Rongbo; Li, Benjin; Chen, Qinghe; Weng, Qiyong

2018-04-01

Phytophthora capsici, an economically devastating oomycete pathogen, causes devastating disease epidemics on a wide range of vegetable plants and pose a grave threat to global vegetables production. Heavy metals and acid pH are newly co-occurring stresses to soil micro-organisms, but what can be expected for mycelia growth and virulence and how they injure the oomycetes (especially P. capsici) remains unknown. Here, the effects of different heavy metals (Cu 2+ , Cr 2+ , and Hg 2+ ) on mycelia growth and virulence were investigated at different pHs (4.0 vs. 7.0) and the plausible molecular and physiological mechanisms were analyzed. In the present study, we compared the effective inhibition of different heavy metals (Cu 2+ , Cr 2+ , and Hg 2+ ) and acid pH on a previously genome sequenced P. capsici virulent strain LT1534. Both stress factors independently affected its mycelia growth and sporulation. Next, we investigated whether ROS participated in the pH-inhibited mycelial growth, finding that the ROS scavenger, catalase (CAT), significantly inhibited the acid pH-induced ROS in mycelia. Additionally, because MAPK specially transmits different stress responsive signals in environment into cells, we employed CAT and a p38-MAPK pathway inhibitor to investigate ROS and p38-MAPK roles in heavy metal-inhibited mycelia growth at different pHs (4.0 vs. 7.0), finding that they significantly inhibited growth. Furthermore, ROS and p38-MAPK influenced the heavy metal-induced TBARS content, total antioxidant capacity (TAC), and CAT activity at different pHs, and also reduced the expression of infection-related laccases (PcLAC2) and an effector-related protein (PcNLP14). We propose that acid pH stress accelerates how heavy metals inhibit mycelium growth, sporulation, and virulence change in P. capsici, and posit that ROS and p38-MAPK function to regulate the molecular and physiological mechanisms underlying this toxicity. Although these stresses induce molecular and physiological challenges to oomycetes, much remains to be known the mechanisms dedicated to resolve these environmental stresses. Copyright © 2018 Elsevier Ltd. All rights reserved.

Uridine 5′-Triphosphate Promotes In Vitro Schwannoma Cell Migration through Matrix Metalloproteinase-2 Activation

PubMed Central

Martiañez, Tania; Segura, Mònica; Figueiro-Silva, Joana; Grijota-Martinez, Carmen; Trullas, Ramón; Casals, Núria

2014-01-01

In response to peripheral nerve injury, Schwann cells adopt a migratory phenotype and modify the extracellular matrix to make it permissive for cell migration and axonal re-growth. Uridine 5′-triphosphate (UTP) and other nucleotides are released during nerve injury and activate purinergic receptors expressed on the Schwann cell surface, but little is known about the involvement of purine signalling in wound healing. We studied the effect of UTP on Schwannoma cell migration and wound closure and the intracellular signaling pathways involved. We found that UTP treatment induced Schwannoma cell migration through activation of P2Y2 receptors and through the increase of extracellular matrix metalloproteinase-2 (MMP-2) activation and expression. Knockdown P2Y2 receptor or MMP-2 expression greatly reduced wound closure and MMP-2 activation induced by UTP. MMP-2 activation evoked by injury or UTP was also mediated by phosphorylation of all 3 major mitogen-activated protein kinases (MAPKs): JNK, ERK1/2, and p38. Inhibition of these MAPK pathways decreased both MMP-2 activation and cell migration. Interestingly, MAPK phosphorylation evoked by UTP exhibited a biphasic pattern, with an early transient phosphorylation 5 min after treatment, and a late and sustained phosphorylation that appeared at 6 h and lasted up to 24 h. Inhibition of MMP-2 activity selectively blocked the late, but not the transient, phase of MAPK activation. These results suggest that MMP-2 activation and late MAPK phosphorylation are part of a positive feedback mechanism to maintain the migratory phenotype for wound healing. In conclusion, our findings show that treatment with UTP stimulates in vitro Schwannoma cell migration and wound repair through a MMP-2-dependent mechanism via P2Y2 receptors and MAPK pathway activation. PMID:24905332

Regulation of RAW 264.7 cell-mediated immunity by polysaccharides from Agaricus blazei Murill via the MAPK signal transduction pathway.

PubMed

Cheng, Feier; Yan, Xiaoyan; Zhang, Miaoqing; Chang, Mingchang; Yun, Shaojun; Meng, Junlong; Liu, Jingyu; Feng, Cui-Ping

2017-04-19

Agaricus blazei Murill (ABM) is a common anticancer folk remedy. Its active ingredients, i.e., polysaccharides, have been isolated and exhibit indirect tumor-suppressing activity via immunological activation. The effects of polysaccharides derived from A. blazei Murill (ABMP) on RAW 264.7 cells were examined by western blotting and real-time reverse transcription polymerase chain reaction (RT-PCR). The effects of 500, 1000, and 2000 μg mL -1 ABMP on the growth of RAW 264.7 cells were evaluated by measuring the OD 490 value; the optimum concentration was found to be 1000 μg mL -1 . Based on the RT-PCR results, the expression levels of JNK, ERK, and p38 decreased substantially in lipopolysaccharide (LPS)-induced RAW 264.7 cells treated with ABMP. In RAW 264.7 cells treated with LPS, the protein expression levels of JNK, ERK, and p38 were decreased, as were the levels of phosphorylated JNK, ERK, and p38. These results indicate that the MAPK signal transduction pathway is a potential mechanism by which ABMP regulates the cell-mediated immunity of RAW 264.7 cells.

Up-regulation of IL-23 expression in human dental pulp fibroblasts by IL-17 via activation of the NF-κB and MAPK pathways.

PubMed

Wei, L; Liu, M; Xiong, H; Peng, B

2017-11-06

To investigate the effects of the pro-inflammatory and Th17-polarizing mediator IL-17 on HDPFs-mediated IL-23 production and the molecular mechanism involved. Interleukin (IL)-17R expression was determined by semi-quantitative reverse transcriptase-polymerase chain reaction and Western blot in cultured human dental pulp fibroblasts (HDPFs). Quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay were used to determine IL-23 mRNA and protein levels in IL-17-stimulated HDPFs, respectively. The nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) signalling pathways that mediate the IL-17-stimulated production of IL-23 was investigated using Western blot and specific signalling inhibitor analyses. Statistical analyses were performed using Kruskal-Wallis tests followed by the Mann-Whitney U-test. Statistical significance was considered when the P value < 0.05. Primary HDPFs steadily expressed IL-17R mRNA and surface-bound protein. IL-17 stimulated the expression of IL-23 mRNA and protein in cultured human dental pulp fibroblasts, which was attenuated by IL-17 or IL-17R neutralizing antibodies. In accordance with the enhanced expression of IL-23, IL-17 stimulation resulted in rapid activation of p38 MAPK, extracellular signal-regulated kinase (ERK) 1/2, c-Jun-N-terminal kinase (JNK) and NF-κB in HDPFs. Inhibitors of p38 MAPK, ERK 1/2 or NF-κB significantly suppressed, whereas blocking JNK substantially augmented IL-23 production from IL-17-stimulated HDPFs. HDPFs expressed IL-17R and responded to IL-17 to produce IL-23 via the activation of the NF-κB and MAPK signalling pathways. The findings provide insights into the cellular mechanisms of the participation of IL-17 in the activation of HDPFs in inflamed pulp tissue. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

MAPK signaling pathways and HDAC3 activity are disrupted during differentiation of emerin-null myogenic progenitor cells

PubMed Central

Collins, Carol M.; Ellis, Joseph A.

2017-01-01

ABSTRACT Mutations in the gene encoding emerin cause Emery–Dreifuss muscular dystrophy (EDMD). Emerin is an integral inner nuclear membrane protein and a component of the nuclear lamina. EDMD is characterized by skeletal muscle wasting, cardiac conduction defects and tendon contractures. The failure to regenerate skeletal muscle is predicted to contribute to the skeletal muscle pathology of EDMD. We hypothesize that muscle regeneration defects are caused by impaired muscle stem cell differentiation. Myogenic progenitors derived from emerin-null mice were used to confirm their impaired differentiation and analyze selected myogenic molecular pathways. Emerin-null progenitors were delayed in their cell cycle exit, had decreased myosin heavy chain (MyHC) expression and formed fewer myotubes. Emerin binds to and activates histone deacetylase 3 (HDAC3). Here, we show that theophylline, an HDAC3-specific activator, improved myotube formation in emerin-null cells. Addition of the HDAC3-specific inhibitor RGFP966 blocked myotube formation and MyHC expression in wild-type and emerin-null myogenic progenitors, but did not affect cell cycle exit. Downregulation of emerin was previously shown to affect the p38 MAPK and ERK/MAPK pathways in C2C12 myoblast differentiation. Using a pure population of myogenic progenitors completely lacking emerin expression, we show that these pathways are also disrupted. ERK inhibition improved MyHC expression in emerin-null cells, but failed to rescue myotube formation or cell cycle exit. Inhibition of p38 MAPK prevented differentiation in both wild-type and emerin-null progenitors. These results show that each of these molecular pathways specifically regulates a particular stage of myogenic differentiation in an emerin-dependent manner. Thus, pharmacological targeting of multiple pathways acting at specific differentiation stages may be a better therapeutic approach in the future to rescue muscle regeneration in vivo. PMID:28188262

Induction of expression of iNOS by N-nitrosodimethylamine (NDMA) in human leukocytes.

PubMed

Ratajczak-Wrona, Wioletta; Jablonska, Ewa; Jablonski, Jakub; Marcinczyk, Magdalena

2009-01-01

The aim of this study was to assess the influence of N-nitrosodimethylamine (NDMA) on expression of inducible nitric oxide synthase (iNOS), as well as production of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) by human neutrophils (PMN) and peripheral blood mononuclear cells (PBMC), and the participation of the p38 MAPK kinase in this process. Furthermore, the ability of neutrophils to release superoxide anion was determined. The influence of N-nitrosodimethylamine on iNOS expression was determined in isolated PMN and PBMC cells from peripheral blood of healthy individuals. The mononuclear cells showed higher sensitivity to NDMA. Moreover, cytotoxic effect of NDMA can be influenced in some way by the impact of this xenobiotic on nitric oxide and superoxide anion release from human leukocytes. Furthermore, increased generation of these radicals by human leukocytes suggest that neutrophils and mononuclear cells that are exposed to NDMA activity can play a key role in endogenous NDMA generation. However the relationship between iNOS expression and phospho-p38 MAPK in neutrophils and mononuclear cells shows that p38 MAPK pathway participates in induction of iNOS expression in the presence of NDMA.

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

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.

Naringin protects ultraviolet B-induced skin damage by regulating p38 MAPK signal pathway.

PubMed

Ren, Xiaolin; Shi, Yuling; Zhao, Di; Xu, Mengyu; Li, Xiaolong; Dang, Yongyan; Ye, Xiyun

2016-05-01

Naringin is a bioflavonoid and has free radical scavenging and anti-inflammatory properties. We examined the effects of naringin on skin after ultraviolet radiation B (UVB) irradiation and the signal pathways by in vitro and in vivo assay. HaCaT cells pretreated with naringin significantly inhibited UVB induced-cell apoptosis and production of intracellular reactive oxygen species (ROS). The expressions of interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2) in HaCaT cells pretreated with naringin were decreased compared with the only UVB group. Also, the activation of p38 induced by UVB in HaCaT cells was reversed by naringin treatments. The inhibition function of naringin on p38 activity was more obvious than JNK. In vivo, topical treatments with naringin prevented the increase of epidermal thickness, IL-6 production, cell apoptosis and the overexpression of COX-2 in BALB/c mice skin irradiated with UVB. Naringin treatment also markedly blocked the activation of p38 in response to UVB stimulation in the mouse skin. Naringin can effectively protect against UVB-induced keratinocyte apoptosis and skin damage by inhibiting ROS production, COX-2 overexpression and strong inflammation reactions. It seemed that naringin played its role against UVB-induced skin damage through inhibition of mitogen-activated protein kinase (MAPK)/p38 activation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Piper betle leaf extracts induced human hepatocellular carcinoma Hep3B cell death via MAPKs regulating the p73 pathway in vitro and in vivo.

PubMed

Wu, Pei-Fang; Tseng, Hsien-Chun; Chyau, Charng-Cherng; Chen, Jing-Hsien; Chou, Fen-Pi

2014-12-01

Extracts of Piper betle leaf (PBLs) are rich in bioactive compounds with potential chemopreventive ability. In this study, Hep3B cells which are p53 null were used to investigate the anti-tumor effect of PBLs in the cell and in the xenograft model. The results revealed that PBLs (0.1 to 1 mg mL(-1)) induced a dose- and time-dependent increase of cell toxicity. The underlying mechanisms as evidenced by flow cytometry and western blot analysis showed that PBLs triggered ATM, cAbl, and p73 expressions and activated JNK and p38 pathways that subsequently led to cell cycle arrest and mitochondria-dependent apoptosis. PBLs also inhibited tumor growth in Hep3B-bearing mice via inducing the MAPK-p73 pathway. Our results demonstrated the in vitro and in vivo anti-tumor potential of PBLs, supporting their application as a novel chemopreventive agent for the treatment of human hepatocellular carcinoma (HCC) in the future via targeting the p73 pathway.

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

PubMed

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

2016-04-01

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

Jinlida reduces insulin resistance and ameliorates liver oxidative stress in high-fat fed rats.

PubMed

Liu, Yixuan; Song, An; Zang, Shasha; Wang, Chao; Song, Guangyao; Li, Xiaoling; Zhu, Yajun; Yu, Xian; Li, Ling; Wang, Yun; Duan, Liyuan

2015-03-13

Jinlida (JLD) is a compound preparation formulated on the basis of traditional Chinese medicine and is officially approved for the treatment of type 2 diabetes (T2DM) in China. We aimed to elucidate the mechanism of JLD treatment, in comparison to metformin treatment, on ameliorating insulin sensitivity in insulin resistant rats and to reveal its anti-oxidant properties. Rats were fed with standard or high-fat diet for 6 weeks. After 6 weeks, the high-fat fed rats were subdivided into five groups and orally fed with JLD or metformin for 8 weeks. Fasting blood glucose (FBG), fasting blood insulin, blood lipid and antioxidant enzymes were measured. Intraperitoneal glucose tolerance test (IPGTT) and hyperinsulinemic euglycemic clamp technique were carried out to measure insulin sensitivity. Gene expression of the major signaling pathway molecules that regulate glucose uptake, including insulin receptor (INSR), insulin receptor substrate-1 (IRS-1), phosphoinositide-3-kinase (PI3K), protein kinase beta (AKT), and glucose transporter type 2 (GLUT2), were assessed by quantitative RT-PCR. The totle and phosphorylation expression of IRS-1, AKT, JNK and p38MAPK were determined by Western blot. Treatment with JLD effectively ameliorated the high-fat induced hyperglycemia, hyperinsulinemia and hyperlipidemia. Similar to metformin, the high insulin resistance in high-fat fed rats was significantly decreased by JLD treatment. JLD displayed anti-oxidant effects, coupled with up-regulation of the insulin signaling pathway. The attenuation of hepatic oxidative stress by JLD treatment was associated with reduced phosphorylation protein levels of JNK and p38MAPK. Treatment with JLD could moderate glucose and lipid metabolism as well as reduce hepatic oxidative stress, most likely through the JNK and p38MAPK pathways. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Amelioration of lesions associated with 24-hour suboptimal platelet storage at 16 °C by a p38MAPK inhibitor, VX-702.

PubMed

Wagner, S J; Skripchenko, A; Seetharaman, S; Kurtz, J

2015-04-01

Previous studies with p38MAPK inhibitors at room temperature demonstrated that they improve a large number of platelet storage parameters, but cannot substantially inhibit p38MAPK activation nor protect against widespread decrements in platelet quality parameters during 4 °C storage. In this study, platelet quality parameters and inhibition of p38MAPK by VX-702 were studied after incubation of platelets at 16 °C without agitation, suboptimal storage conditions which produce moderate platelet decrements. Trima apheresis units were collected and aliquoted into three 60-ml CLX storage bags: (i) a control aliquot which was held at 20-24 °C with constant agitation; (ii) a test aliquot which was held at 20-24 °C with agitation until Day 2, when it was reincubated at 16 ± 1 °C for 24 ± 0·5 h without agitation and then returned 20-24 °C with agitation; (iii) a test aliquot containing 1 μm VX-702 stored in an identical fashion as aliquot 2. Aliquots were tested for an array of platelet storage parameters and p38MAPK activation on Days 1, 4 and 7. Many platelet storage parameters and p38MAPK activation were adversely affected by 24-h incubation at 16 °C without agitation. With the exception of ESC, addition of VX-702 prevented p38MAPK activation and the decrements in most observed parameters. Unlike 4 °C storage, VX-702 prevents activation of p38MAPK and decrements in many platelet storage parameters after exposure to 16 °C without agitation for 24 h. © 2014 International Society of Blood Transfusion.

Adult-onset hyperthyroidism impairs spatial learning: possible involvement of mitogen-activated protein kinase signaling pathways.

PubMed

Bitiktaş, Soner; Kandemir, Başak; Tan, Burak; Kavraal, Şehrazat; Liman, Narin; Dursun, Nurcan; Dönmez-Altuntaş, Hamiyet; Aksan-Kurnaz, Işil; Suer, Cem

2016-08-03

Given evidence that mitogen-activated protein kinase (MAPK) activation is part of the nongenomic actions of thyroid hormones, we investigated the possible consequences of hyperthyroidism for the cognitive functioning of adult rats. Young adult rats were treated with L-thyroxine or saline. Twenty rats in each group were exposed to Morris water maze testing, measuring their performance in a hidden-platform spatial task. In a separate set of rats not exposed to Morris water maze testing (untrained rats), the expression and phosphorylated levels of p38-MAPK and of its two downstream effectors, Elk-1 and cAMP response element-binding protein, were evaluated using quantitative reverse transcriptase-PCR and western blotting. Rats with hyperthyroidism showed delayed acquisition of learning compared with their wild-type counterparts, as shown by increased escape latencies and distance moved on the last two trials of daily training in the water maze. The hyperthyroid rats, however, showed no difference during probe trials. Western blot analyses of the hippocampus showed that hyperthyroidism increased phosphorylated p38-MAPK levels in untrained rats. Although our study is correlative in nature and does not exclude the contribution of other molecular targets, our findings suggest that the observed impairments in acquisition during actual learning in rats with hyperthyroidism may result from the increased phosphorylation of p38-MAPK.

INTRACELLULAR SIGNALING BY BILE ACIDS

PubMed Central

Anwer, Mohammed Sawkat

2014-01-01

Bile acids, synthesized from cholesterol, are known to produce beneficial as well as toxic effects in the liver. The beneficial effects include choleresis, immunomodulation, cell survival, while the toxic effects include cholestasis, apoptosis and cellular toxicity. It is believed that bile acids produce many of these effects by activating intracellular signaling pathways. However, it has been a challenge to relate intracellular signaling to specific and at times opposing effects of bile acids. It is becoming evident that bile acids produce different effects by activating different isoforms of phosphoinositide 3-kinase (PI3K), Protein kinase Cs (PKCs), and mitogen activated protein kinases (MAPK). Thus, the apoptotic effect of bile acids may be mediated via PI3K-110γ, while cytoprotection induce by cAMP-GEF pathway involves activation of PI3K-p110α/β isoforms. Atypical PKCζ may mediate beneficial effects and nPKCε may mediate toxic effects, while cPKCα and nPKCδ may be involved in both beneficial and toxic effects of bile acids. The opposing effects of nPKCδ activation may depend on nPKCδ phosphorylation site(s). Activation of ERK1/2 and JNK1/2 pathway appears to mediate beneficial and toxic effects, respectively, of bile acids. Activation of p38α MAPK and p38β MAPK may mediate choleretic and cholestatic effects, respectively, of bile acids. Future studies clarifying the isoform specific effects on bile formation should allow us to define potential therapeutic targets in the treatment of cholestatic disorders. PMID:25378891

VEGF isoforms have differential effects on permeability of human pulmonary microvascular endothelial cells.

PubMed

Ourradi, Khadija; Blythe, Thomas; Jarrett, Caroline; Barratt, Shaney L; Welsh, Gavin I; Millar, Ann B

2017-06-02

Alternative splicing of Vascular endothelial growth factor-A mRNA transcripts (commonly referred as VEGF) leads to the generation of functionally differing isoforms, the relative amounts of which have potentially significant physiological outcomes in conditions such as acute respiratory distress syndrome (ARDS). The effect of such isoforms on pulmonary vascular permeability is unknown. We hypothesised that VEGF 165 a and VEGF 165 b isoforms would have differing effects on pulmonary vascular permeability caused by differential activation of intercellular signal transduction pathways. To test this hypothesis we investigated the physiological effect of VEGF 165 a and VEGF 165 b on Human Pulmonary Microvascular Endothelial Cell (HPMEC) permeability using three different methods: trans-endothelial electrical resistance (TEER), Electric cell-substrate impedance sensing (ECIS) and FITC-BSA passage. In addition, potential downstream signalling pathways of the VEGF isoforms were investigated by Western blotting and the use of specific signalling inhibitors. VEGF 165 a increased HPMEC permeability using all three methods (paracellular and transcellular) and led to associated VE-cadherin and actin stress fibre changes. In contrast, VEGF 165 b decreased paracellular permeability and did not induce changes in VE-cadherin cell distribution. Furthermore, VEGF 165 a and VEGF 165 b had differing effects on both the phosphorylation of VEGF receptors and downstream signalling proteins pMEK, p42/44MAPK, p38 MAPK, pAKT and peNOS. Interestingly specific inhibition of the pMEK, p38 MAPK, PI3 kinase and eNOS pathways blocked the effects of both VEGF 165 a and VEGF 165 b on paracellular permeability and the effect of VEGF 165 a on proliferation/migration, suggesting that this difference in cellular response is mediated by an as yet unidentified signalling pathway(s). This study demonstrates that the novel isoform VEGF 165 a and VEGF 165 b induce differing effects on permeability in pulmonary microvascular endothelial cells.

[The effect of edaravone on MAPKs signal pathway associated with Abeta(25-35) treatment in PC12 cells].

PubMed

Zhang, Gui-lian; Guo, Ying-ying; Zhang, Lei; Li, Ting-ting; Du, Yun; Yao, Li; Zhang, Wang-gang; Wu, Hai-qin; Ma, Zhu-lin

2015-03-01

To explore whether edaravone protects cells damage via mitogen-activated protein kinases (MAPKs) signal pathway, and which procedure of p38 be affected so as to add theories for AD pathogenesis and treatments. According to different drugs treated, PC12 cells in vitro were divided into four groups. Negative control group: cells were treated with media alone. AD model group: cells were treated with 30 pmol/L Abeta(25-35). Inhibitor control group: cells were treated with 10 micromol/L SB203580 Cp38 mitogen-activated protein kinase (p38) inhibitor], 10 micromol/L SP600125 [c-Jun NH2 terminal kinase (JNK) inhibitor], or 10 micromol/L PD98059 extracelular signal regulated kinase (ERK) inhibitor]. Low-dose, middle-dose and high-dose edaravone group: cells plated for 24 hours treated with 30 micromol/L Abeta(25-35) and co-treated with 20, 40, 80 micromol/L edaravone 3 hours, respectively. The morphology of the treated cells were observed, the p-p38, p-JNK and p-ERK proteins in each group were tested by the Western blot. The p38 mRNA were tested in each group above (only add SB203580 10 micromol/L in third group) by the real time PCR. (1) The p-p38 protein was significantly increased in model control group compared with that in negative control group (P<0.05). The p-p38 protein in the inhibitor group and edaravone groups was decreased significantly (P<0.05) when compared with that in model control group. The p-p38 proteins were significantly increased in the three edaravone groups compared with that in inhibiter control group (P<0.05). The p-p38 protein in middle-dose edaravone group was decreased compared with that in low-dose edaravone group (P<0.05). There was no relationship in dose-dependent manner about edaravone. Compared with three edaravone groups, the p-p38 protein was lower than it in high-dose edaravone & inhibiter group (P<0.05). (2) The p-JNK protein was significantly increased in model control group compared with that in negative control group (P<0.05). The p-JNK protein in the inhibitor group was decreased compared with that in model control group (P<0.05). (3) No significantly difference of p-ERK protein concentration was observed in other groups when compared with that in negative control group (P>0.05 each). (4) Compared with negative control group, the p38 mRNA in model control group was significantly increased, and it was significantly decreased in inhibitor control group (P<0.05 each). In 40 micromol/L and 80 micromol/L edaravone groups, the p38 mRNA was significantly decreased compared with that in model control group, and it still was decreased compared with that in inhibitor control group (P<0.05). The p38 mRNA in 40 micromol/L edaravone group was the lowest among three edaravone groups, and it was obviously different from that in 20 micromol/L and 80 micromol/L edaravone groups (P<0.05). Abeta(25-35) could increase the p-p38 and p-JNK protein expression in cultured PC12 cells, but there was no obviously expression of p-ERK protein. These indicated that Abeta(25-35) might activate MAPKs signal pathway, especially p38 and JNK, and lead to PC12 cell damage. Edaravone could decrease p38 mRNA induced-Abeta(25-35), which indicated edaravone could protect PC12 cell damage via blocking p38 signal pathway in mRNA stage and protein stage simultaneously. Hence, it is promising that edaravone would be a new medicine for AD.

Functional Roles of p38 Mitogen-Activated Protein Kinase in Macrophage-Mediated Inflammatory Responses

PubMed Central

Yang, Yanyan; Yu, Tao; Sung, Gi-Ho; Yoo, Byong Chul

2014-01-01

Inflammation is a natural host defensive process that is largely regulated by macrophages during the innate immune response. Mitogen-activated protein kinases (MAPKs) are proline-directed serine and threonine protein kinases that regulate many physiological and pathophysiological cell responses. p38 MAPKs are key MAPKs involved in the production of inflammatory mediators, including tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2). p38 MAPK signaling plays an essential role in regulating cellular processes, especially inflammation. In this paper, we summarize the characteristics of p38 signaling in macrophage-mediated inflammation. In addition, we discuss the potential of using inhibitors targeting p38 expression in macrophages to treat inflammatory diseases. PMID:24771982

Secondhand Smoke-Prevalent Polycyclic Aromatic Hydrocarbon Binary Mixture-Induced Specific Mitogenic and Pro-inflammatory Cell Signaling Events in Lung Epithelial Cells.

PubMed

Osgood, Ross S; Upham, Brad L; Bushel, Pierre R; Velmurugan, Kalpana; Xiong, Ka-Na; Bauer, Alison K

2017-05-01

Low molecular weight polycyclic aromatic hydrocarbons (LMW PAHs; < 206.3 g/mol) are prevalent and ubiquitous environmental contaminants, presenting a human health concern, and have not been as thoroughly studied as the high MW PAHs. LMW PAHs exert their pulmonary effects, in part, through P38-dependent and -independent mechanisms involving cell-cell communication and the production of pro-inflammatory mediators known to contribute to lung disease. Specifically, we determined the effects of two representative LMW PAHs, 1-methylanthracene (1-MeA) and fluoranthene (Flthn), individually and as a binary PAH mixture on the dysregulation of gap junctional intercellular communication (GJIC) and connexin 43 (Cx43), activation of mitogen activated protein kinases (MAPK), and induction of inflammatory mediators in a mouse non-tumorigenic alveolar type II cell line (C10). Both 1-MeA, Flthn, and the binary PAH mixture of 1-MeA and Flthn dysregulated GJIC in a dose and time-dependent manner, reduced Cx43 protein, and activated the following MAPKs: P38, ERK1/2, and JNK. Inhibition of P38 MAPK prevented PAH-induced dysregulation of GJIC, whereas inhibiting ERK and JNK did not prevent these PAHs from dysregulating GJIC indicating a P38-dependent mechanism. A toxicogenomic approach revealed significant P38-dependent and -independent pathways involved in inflammation, steroid synthesis, metabolism, and oxidative responses. Genes in these pathways were significantly altered by the binary PAH mixture when compared with 1-MeA and Flthn alone suggesting interactive effects. Exposure to the binary PAH mixture induced the production and release of cytokines and metalloproteinases from the C10 cells. Our findings with a binary mixture of PAHs suggest that combinations of LMW PAHs may elicit synergistic or additive inflammatory responses which warrant further investigation and confirmation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Secondhand Smoke-Prevalent Polycyclic Aromatic Hydrocarbon Binary Mixture-Induced Specific Mitogenic and Pro-inflammatory Cell Signaling Events in Lung Epithelial Cells

PubMed Central

Osgood, Ross S.; Upham, Brad L.; Bushel, Pierre R.; Velmurugan, Kalpana; Xiong, Ka-Na

2017-01-01

Abstract Low molecular weight polycyclic aromatic hydrocarbons (LMW PAHs; < 206.3 g/mol) are prevalent and ubiquitous environmental contaminants, presenting a human health concern, and have not been as thoroughly studied as the high MW PAHs. LMW PAHs exert their pulmonary effects, in part, through P38-dependent and -independent mechanisms involving cell-cell communication and the production of pro-inflammatory mediators known to contribute to lung disease. Specifically, we determined the effects of two representative LMW PAHs, 1-methylanthracene (1-MeA) and fluoranthene (Flthn), individually and as a binary PAH mixture on the dysregulation of gap junctional intercellular communication (GJIC) and connexin 43 (Cx43), activation of mitogen activated protein kinases (MAPK), and induction of inflammatory mediators in a mouse non-tumorigenic alveolar type II cell line (C10). Both 1-MeA, Flthn, and the binary PAH mixture of 1-MeA and Flthn dysregulated GJIC in a dose and time-dependent manner, reduced Cx43 protein, and activated the following MAPKs: P38, ERK1/2, and JNK. Inhibition of P38 MAPK prevented PAH-induced dysregulation of GJIC, whereas inhibiting ERK and JNK did not prevent these PAHs from dysregulating GJIC indicating a P38-dependent mechanism. A toxicogenomic approach revealed significant P38-dependent and -independent pathways involved in inflammation, steroid synthesis, metabolism, and oxidative responses. Genes in these pathways were significantly altered by the binary PAH mixture when compared with 1-MeA and Flthn alone suggesting interactive effects. Exposure to the binary PAH mixture induced the production and release of cytokines and metalloproteinases from the C10 cells. Our findings with a binary mixture of PAHs suggest that combinations of LMW PAHs may elicit synergistic or additive inflammatory responses which warrant further investigation and confirmation. PMID:28329830

Andrographolide Antagonizes TNF-α-Induced IL-8 via Inhibition of NADPH Oxidase/ROS/NF-κB and Src/MAPKs/AP-1 Axis in Human Colorectal Cancer HCT116 Cells.

PubMed

Yuan, Miaomiao; Meng, Wei; Liao, Wenzhen; Lian, Sen

2018-05-14

Andrographis paniculata Nees is used as a functional food in Japan, Korea, India, and China. Andrographolide, a naturally occurring phytochemical identified in Andrographis paniculata, has been discovered to present anti-inflammatory and anticancer activities. Highly expressed interleukin (IL-8) has been detected in colorectal cancer and is implicated in angiogenesis. However, the effect and molecular mechanisms of IL-8 expression by andrographolide remain obscure in human colorectal cancer cells. The present study was aimed to investigate the effects of andrographolide on TNF-α-induced IL-8 expression and its underlying mechanisms. We found that andrographolide concentration-dependently inhibited TNF-α-induced IL-8 mRNA (2.23 ± 0.15 fold at 20 μM) and protein expression (4.78 ± 0.31 fold at 20 μM) and reduced the IL-8 transcriptional activity (2.59 ± 0.25 fold at 20 μM). TNF-α stimulated the membrane translocation of p47 phox to activate reactive oxygen species (ROS)-producing NADPH oxidase (NOX). Furthermore, TNF-α induced Src and MAPKs (Erk1/2, p38 MAPK) phosphorylation, as well as NF-κB and AP-1 binding activities. We found that NF-κB and AP-1 were the critical transcription factors for TNF-α-induced IL-8 expression. Specific inhibitors and mutagenesis studies indicated that Src, Erk1/2, and p38 MAPK are related to TNF-α-induced IL-8. NOX-derived ROS and Src/MAPKs (Erk1/2 and p38 MAPK) functioned as upstream activators of NF-κB and AP-1, respectively. Taken together, andrographolide antagonizes TNF-α-induced IL-8 via inhibition of NADPH oxidase/ROS/NF-κB and Src/MAPKs/AP-1 signaling pathways in HCT116 colorectal cancer cells and then suppresses angiogenesis in the tumor microenvironment.

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.

Red ginseng marc oil inhibits iNOS and COX-2 via NFκB and p38 pathways in LPS-stimulated RAW 264.7 macrophages.

PubMed

Bak, Min-Ji; Hong, Soon-Gi; Lee, Jong-Won; Jeong, Woo-Sik

2012-11-22

In this study, we investigated the anti-inflammatory effects of red ginseng marc oil (RMO) in the RAW 264.7 macrophage cell line. RMO was prepared by a supercritical CO(2) extraction of waste product generated after hot water extraction of red ginseng. RMO significantly inhibited the production of oxidative stress molecules such as nitric oxide and reactive oxygen species in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Levels of inflammatory targets including prostaglandin E2, tumor necrosis factor-α, interleukin (IL)-1β and IL-6 were also reduced after the treatment with RMO. In addition, RMO diminished the expressions of inducible nitric oxide synthase and cyclooxygenase 2 at both mRNA and protein levels. Blockade of nuclear translocation of the p65 subunit of nuclear factor κB (NFκB) was also observed after the treatment of RMO. Furthermore, RMO decreased the phosphorylations of p38 mitogen-activated protein kinase (MAPK) and its upstream kinases including MAPK kinases 3/6 (MKK3/6) and TAK 1 (TGF-β activated kinase 1). Gas chromatographic analysis on RMO revealed that RMO contained about 10% phytosterols including sitosterol, stigmasterol and campesterol which may contribute to the anti-inflammatory properties of RMO. Taken together, these results suggest that the anti-inflammatory effect of RMO in LPS-induced RAW 264.7 macrophages could be associated with the inhibition of NFκB transcriptional activity, possibly via blocking the p38 MAPK pathway.

Two distinct roles of mitogen-activated protein kinases in platelets and a novel Rac1-MAPK–dependent integrin outside-in retractile signaling pathway

PubMed Central

Flevaris, Panagiotis; Li, Zhenyu; Zhang, Guoying; Zheng, Yi; Liu, Junling

2009-01-01

Mitogen-activated protein kinases (MAPK), p38, and extracellular stimuli-responsive kinase (ERK), are acutely but transiently activated in platelets by platelet agonists, and the agonist-induced platelet MAPK activation is inhibited by ligand binding to the integrin αIIbβ3. Here we show that, although the activation of MAPK, as indicated by MAPK phosphorylation, is initially inhibited after ligand binding to integrin αIIbβ3, integrin outside-insignaling results in a late but sustained activation of MAPKs in platelets. Furthermore, we show that the early agonist-induced MAPK activation and the late integrin-mediated MAPK activation play distinct roles in different stages of platelet activation. Agonist-induced MAPK activation primarily plays an important role in stimulating secretion of platelet granules, while integrin-mediated MAPK activation is important in facilitating clot retraction. The stimulatory role of MAPK in clot retraction is mediated by stimulating myosin light chain (MLC) phosphorylation. Importantly, integrin-dependent MAPK activation, MAPK-dependent MLC phosphorylation, and clot retraction are inhibited by a Rac1 inhibitor and in Rac1 knockout platelets, indicating that integrin-induced activation of MAPK and MLC and subsequent clot retraction is Rac1-dependent. Thus, our results reveal 2 different activation mechanisms of MAPKs that are involved in distinct aspects of platelet function and a novel Rac1-MAPK–dependent cell retractile signaling pathway. PMID:18957688

Activation of p38 MAP Kinase is Involved in Central Neuropathic Pain Following Spinal Cord Injury

PubMed Central

Crown, Eric D; Gwak, Young Seob; Ye, Zaiming; Johnson, Kathia M; Hulsebosch, Claire E

2008-01-01

Recent work regarding chronic central neuropathic pain (CNP) following spinal cord injury (SCI) suggests that activation of key signaling molecules such as members of the mitogen activated protein kinase (MAPK) family play a role in the expression of at-level mechanical allodynia. Specifically, Crown and colleagues (2005, 2006) have shown that the development of at-level CNP following moderate spinal cord injury is correlated with increased expression of the activated (and thus phosphorylated) forms of the MAPKs extracellular signal related kinase and p38 MAPK. The current study extends this work by directly examining the role of p38 MAPK in the maintenance of at-level CNP following spinal cord injury. Using a combination of behavioral, immunocytochemical, and electrophysiological measures we demonstrate that increased activation of p38 MAPK occurs in the spinal cord just rostral to the site of injury in rats that develop at-level mechanical allodynia after moderate SCI. Immunocytochemical analyses indicate that the increases in p38 MAPK activation occurred in astrocytes, microglia, and dorsal horn neurons in the spinal cord rostral to the site of injury. Inhibiting the enzymatic activity of p38 MAPK dose dependently reverses the behavioral expression of at-level mechanical allodynia and also decreases the hyperexcitability seen in thoracic dorsal horn neurons after moderate SCI. Taken together, these novel data are the first to demonstrate causality that increased activation of p38 MAPK in multiple cell types play an important role in the maintenance of at-level CNP following spinal cord injury. PMID:18590729

MCP-1-mediated activation of microglia promotes white matter lesions and cognitive deficits by chronic cerebral hypoperfusion in mice.

PubMed

Yuan, Bangqing; Shi, Hui; Zheng, Kuang; Su, Zulu; Su, Hai; Zhong, Ming; He, Xuenong; Zhou, Changlong; Chen, Hao; Xiong, Qijiang; Zhang, Yi; Yang, Zhao

2017-01-01

Microglia activation played a vital role in the pathogenesis of white matter lesions (WMLs) by chronic cerebral hypoperfusion. In addition, hypoxia induced up-regulated expression of MCP-1, promotes the activation of microglia. However, the role of MCP-1-mediated microglia activation in chronic cerebral ischemia is still unknown. To explore that, chronic cerebral hypoperfusion model was established by permanent stenosis of bilateral common carotid artery in mice. The activation of microglia and the related signal pathway p38MAPK/PKC in white matter, and working memory of mice were observed. We found that stenosis of common carotid arteries could induce MCP-1-mediated activation of microglia through p38MAPK/PKC pathway and white matter lesions. Taken together, our findings represent a novel mechanism of MCP-1 involved in activation of microglia and provide a novel therapeutical strategy for chronic cerebral hypoperfusion. Copyright © 2016 Elsevier Inc. All rights reserved.

Pertussis Toxin Exploits Host Cell Signaling Pathways Induced by Meningitis-Causing E. coli K1-RS218 and Enhances Adherence of Monocytic THP-1 Cells to Human Cerebral Endothelial Cells.

PubMed

Starost, Laura Julia; Karassek, Sascha; Sano, Yasuteru; Kanda, Takashi; Kim, Kwang Sik; Dobrindt, Ulrich; Rüter, Christian; Schmidt, Marcus Alexander

2016-10-13

Pertussis toxin (PTx), the major virulence factor of the whooping cough-causing bacterial pathogen Bordetella pertussis , permeabilizes the blood-brain barrier (BBB) in vitro and in vivo. Breaking barriers might promote translocation of meningitis-causing bacteria across the BBB, thereby facilitating infection. PTx activates several host cell signaling pathways exploited by the neonatal meningitis-causing Escherichia coli K1-RS218 for invasion and translocation across the BBB. Here, we investigated whether PTx and E. coli K1-RS218 exert similar effects on MAPK p38, NF-κB activation and transcription of downstream targets in human cerebral endothelial TY10 cells using qRT-PCR, Western blotting, and ELISA in combination with specific inhibitors. PTx and E. coli K1-RS218 activate MAPK p38, but only E. coli K1-RS218 activates the NF-κB pathway. mRNA and protein levels of p38 and NF-κB downstream targets including IL-6, IL-8, CxCL-1, CxCL-2 and ICAM-1 were increased. The p38 specific inhibitor SB203590 blocked PTx-enhanced activity, whereas E. coli K1-RS218's effects were inhibited by the NF-κB inhibitor Bay 11-7082. Further, we found that PTx enhances the adherence of human monocytic THP-1 cells to human cerebral endothelial TY10 cells, thereby contributing to enhanced translocation. These modulations of host cell signaling pathways by PTx and meningitis-causing E. coli support their contributions to pathogen and monocytic THP-1 cells translocation across the BBB.

Pertussis Toxin Exploits Host Cell Signaling Pathways Induced by Meningitis-Causing E. coli K1-RS218 and Enhances Adherence of Monocytic THP-1 Cells to Human Cerebral Endothelial Cells

PubMed Central

Starost, Laura Julia; Karassek, Sascha; Sano, Yasuteru; Kanda, Takashi; Kim, Kwang Sik; Dobrindt, Ulrich; Rüter, Christian; Schmidt, Marcus Alexander

2016-01-01

Pertussis toxin (PTx), the major virulence factor of the whooping cough-causing bacterial pathogen Bordetella pertussis, permeabilizes the blood–brain barrier (BBB) in vitro and in vivo. Breaking barriers might promote translocation of meningitis-causing bacteria across the BBB, thereby facilitating infection. PTx activates several host cell signaling pathways exploited by the neonatal meningitis-causing Escherichia coli K1-RS218 for invasion and translocation across the BBB. Here, we investigated whether PTx and E. coli K1-RS218 exert similar effects on MAPK p38, NF-κB activation and transcription of downstream targets in human cerebral endothelial TY10 cells using qRT-PCR, Western blotting, and ELISA in combination with specific inhibitors. PTx and E. coli K1-RS218 activate MAPK p38, but only E. coli K1-RS218 activates the NF-κB pathway. mRNA and protein levels of p38 and NF-κB downstream targets including IL-6, IL-8, CxCL-1, CxCL-2 and ICAM-1 were increased. The p38 specific inhibitor SB203590 blocked PTx-enhanced activity, whereas E. coli K1-RS218’s effects were inhibited by the NF-κB inhibitor Bay 11-7082. Further, we found that PTx enhances the adherence of human monocytic THP-1 cells to human cerebral endothelial TY10 cells, thereby contributing to enhanced translocation. These modulations of host cell signaling pathways by PTx and meningitis-causing E. coli support their contributions to pathogen and monocytic THP-1 cells translocation across the BBB. PMID:27754355

Signal transduction involved in lipoxin A4-induced protection of tubular epithelial cells against hypoxia/reoxygenation injury

PubMed Central

Wu, Sheng-Hua; Wang, Ming-Jie; Lü, Jing; Chen, Xiao-Qing

2017-01-01

Previous studies have reported that lipoxin A4 (LXA4) may exert a renoprotective effect on ischemia/reperfusion injury in various animal models. The underlying mechanism of LXA4-induced renoprotection during ischemia/reperfusion injury remains to be elucidated. The present study investigated LXA4-induced protection on renal tubular cells subjected to hypoxia/reoxygenation (H/R) injury, and determined the effects of peroxisome proliferator-activated receptor-γ (PPARγ) and heme oxygenase-1 (HO-1) on LXA4 treatment. HK-2 human tubular epithelial cells exposed to H/R injury were pretreated with LXA4, signal molecule inhibitors or the HO-1 inhibitor zinc protoporphyrin-IX, or were transfected with PPARγ small interfering RNA (siRNA) or nuclear factor E2-related factor 2 (Nrf2) siRNA. The protein and mRNA expression levels of PPARγ and HO-1 were analyzed using western blotting and reverse transcription-quantitative polymerase chain reaction. Binding activity of Nrf2 to the HO-1 E1 enhancer was determined using chromatin immunoprecipitation. Nrf2 binding to the HO-1 antioxidant responsive element (ARE) was assessed using electrophoretic mobility shift assay. Preincubation of cells with LXA4 exposed to H/R injury led to a decreased production of inducible nitrogen oxide synthase, malondialdehyde, γ-glutamyl transpeptidase, leucine aminopeptidase and N-acetyl-β-glucosaminidase. In addition, LXA4 pretreatment increased cell viability, protein and mRNA expression levels of PPARγ and HO-1 and PPARγ and HO-1 promoter activity. SB20358 is a p38 mitogen-activated protein kinase (p38 MAPK) pathway inhibitor, which reduced LXA4-induced PPARγ expression levels. LXA4 treatment upregulated p38 MAPK activation, Nrf2 nuclear translocation and increased binding activity of Nrf2 to HO-1 ARE and E1 enhancer in cells exposed to H/R injury. Transfection of the cells with PPARγ siRNA reduced the LXA4-induced Nrf2 translocation. Transfection of the cells with PPARγ siRNA or Nrf2 siRNA also reduced the LXA4-induced increase in HO-1 expression. In conclusion, LXA4-induced protection of renal tubular cells against H/R injury was associated with the induction of PPARγ and HO-1, via activation of the p38 MAPK pathway, as well as Nrf2 nuclear translocation and binding to HO-1 ARE and E1 enhancer. Therefore, LXA4-induced renoprotection is associated with activation of the p38 MAPK/PPARγ/Nrf2-ARE/HO-1 pathway. PMID:28259922

Lipopolysaccharide-regulated production of bone sialoprotein and interleukin-8 in human periodontal ligament fibroblasts: the role of toll-like receptors 2 and 4 and the MAPK pathway.

PubMed

Zhang, Y; Li, X

2015-04-01

Lipopolysaccharide (LPS) on the cell wall of periodontal pathogens is a major mediator of the inflammatory response and can enhance alveolar bone resorption in periodontitis. Bone sialoprotein is an early marker of osteoblast differentiation. The proinflammatory cytokine, interleukin-8 (IL-8), induces osteoclast differentiation, maturation and maintenance of bone resorption activity. However, the effects of LPS from periodontal pathogens on the expression of bone sialoprotein and IL-8 in human osteoblasts and the mechanism of periodontal bone metabolism regulation are rather unclear. The objectives of this study were to determine the effects of Porphyromonas gingivalis LPS on the production of bone sialoprotein and IL-8 in human periodontal ligament fibroblasts (hPDLFs), and to investigate whether toll-like receptor (TLR) 2, TLR4 and MAPKs pathways are involved in the regulation of production of bone sialoprotein and IL-8 by P. gingivalis LPS. The third-generation of hPDLFs were cultured with mineralization-inducing culture medium. After hPDLFs were treated with P. gingivalis LPS, bone sialoprotein and IL-8 mRNA expression were detected using Real time PCR. Then hPDLFs were transiently transfected with siTLR2 or siTLR4 (20 nm) or inhibited by MAPK signaling pathways inhibitors, and then bone sialoprotein and IL-8 mRNA and protein expression were also detected using Real time PCR and western blotting. Treatments with 0.01 and 0.1 mg/L of P. gingivalis LPS for 8 h up-regulated bone sialoprotein mRNA expression, whereas 10 and 100 mg/L of P. gingivalis LPS induced a significant decrease in the expression of bone sialoprotein mRNA. In contrast, IL8 mRNA levels were increased significantly by 10 mg/L of P. gingivalis LPS. Interestingly, small interfering RNA (siRNA) knock down of the TLR2 and ERK1/2 inhibitor, PD98059, abolished the effects of P. gingivalis LPS on the bone sialoprotein mRNA level, whereas siRNA knock down of the TLR2 and p38 MAPK inhibitor, SB203580, blocked the effect of P. gingivalis LPS on IL-8 in hPDLFs. This study suggests that in hPDLFs, P. gingivalis LPS suppresses bone sialoprotein and enhances IL-8 gene and protein expression via TLR2 and ERK1/2 or the p38 MAPK signaling pathway, respectively. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

miR-218 is involved in the negative regulation of osteoclastogenesis and bone resorption by partial suppression of p38MAPK-c-Fos-NFATc1 signaling: Potential role for osteopenic diseases.

PubMed

Qu, Bo; Xia, Xun; Yan, Ming; Gong, Kai; Deng, Shaolin; Huang, Gang; Ma, Zehui; Pan, Xianming

2015-10-15

The increased osteoclastic activity accounts for pathological bone loss in diseases including osteoporosis. MicroRNAs are widely accepted to be involved in the regulation of osteopenic diseases. Recently, the low expression of miR-218 was demonstrated in CD14(+) peripheral blood mononuclear cells (PBMCs) from patients with postmenopausal osteoporosis. However, its role and the underlying mechanism in osteoporosis are still undefined. Here, an obvious decrease in miR-218 expression was observed during osteoclastogenesis under receptor activator of nuclear factor κB ligand (RANKL) stimulation, in both osteoclast precursors of bone marrow macrophages (BMMs) and RAW 264.7. Further analysis confirmed that overexpression of miR-218 obviously attenuated the formation of multinuclear mature osteoclasts, concomitant with the decrease in Trap and Cathepsin K levels, both the master regulators of osteoclastogenesis. Moreover, miR-218 up-regulation dramatically inhibited osteoclast precursor migration, actin ring formation and bone resorption. Mechanism assay demonstrated that miR-218 overexpression attenuated the expression of p38MAPK, c-Fos and NFATc1 signaling molecules. Following preconditioning with P79350, an agonist of p38MAPK, the inhibitor effect of miR-218 on osteoclastogenesis and bone-resorbing activity was strikingly ameliorated. Together, this study revealed a crucial role of miR-218 as a negative regulator for osteoclastogenesis and bone resorption by suppressing the p38MAPK-c-Fos-NFATc1 pathway. Accordingly, this research will provide a promising therapeutic agent against osteopenic diseases including osteoporosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Resveratrol Protects against TNF-α-Induced Injury in Human Umbilical Endothelial Cells through Promoting Sirtuin-1-Induced Repression of NF-KB and p38 MAPK

PubMed Central

Huang, Shujie; Zhu, Pengli

2016-01-01

Inflammation and reactive oxygen species (ROS) play important roles in the pathogenesis of atherosclerosis. Resveratrol has been shown to possess anti-inflammatory and antioxidative stress activities, but the underlying mechanisms are not fully understood. In the present study, we investigated the molecular basis associated with the protective effects of resveratrol on tumor necrosis factor-alpha (TNF-α)-induced injury in human umbilical endothelial cells (HUVECs) using a variety of approaches including a cell viability assay, reverse transcription and quantitative polymerase chain reaction, western blot, and immunofluorescence staining. We showed that TNF-α induced CD40 expression and ROS production in cultured HUVECs, which were attenuated by resveratrol treatment. Also, resveratrol increased the expression of sirtuin 1 (SIRT1); and repression of SIRT1 by small-interfering RNA (siRNA) and the SIRT1 inhibitor Ex527 reduced the inhibitory effects of resveratrol on CD40 expression and ROS generation. In addition, resveratrol downregulated the levels of p65 and phospho-p38 MAPK, but this inhibitory effect was attenuated by the suppression of SIRT1 activity. Moreover, the p38 MAPK inhibitor SD203580 and the nuclear factor (NF)-κB inhibitor pyrrolidine dithiocarbamate (PDTC) achieved similar repressive effects as resveratrol on TNF-α-induced ROS generation and CD40 expression. Thus, our study provides a mechanistic link between resveratrol and the activation of SIRT1, the latter of which is involved in resveratrol-mediated repression of the p38 MAPK/NF-κB pathway and ROS production in TNF-α-treated HUVECs. PMID:26799794

Phosphorylated 4EBP1 is associated with tumor progression and poor prognosis in Xp11.2 translocation renal cell carcinoma.

PubMed

Qu, Yuanyuan; Zhao, Rui; Wang, Hongkai; Chang, Kun; Yang, Xiaoqun; Zhou, Xiaoyan; Dai, Bo; Zhu, Yao; Shi, Guohai; Zhang, Hailiang; Ye, Dingwei

2016-03-30

Two main signaling pathways, PI3K-AKT-mTOR and RAS-MAPK, are involved in transmitting the proliferative signals which play critical roles in human cancers. However, the functions of these pathways in Xp11.2 RCC remain undefined. This study aimed to explore the expression of mTOR and MAPK cascades in Xp11.2 RCC and to assess the prognostic significance of proteins evaluated. Immunohistochemistry was performed to evaluate the expression of 4EBP1, p-4EBP1, p-mTOR, p-S6K and p-MAPK in 36 adult Xp11.2 RCC patients who were confirmed by FISH assay. Cox regression models were used to evaluate the prognostic value of all covariates. Among 36 assessed patients, 14 (38.9%), 26 (72.2%), 16 (44.4%), 19 (52.8%), and 9 (25.0%) patients showed high expression of 4EBP1, p-4EBP1, p-mTOR, p-S6K, and p-MAPK, respectively. We noted that p-4EBP1 expression was significantly correlated with lymph node metastases (P = 0.027). Multivariate analysis showed that high p-4EBP1 expression was an independent adverse prognostic factor for both PFS (HR = 33.750, P = 0.017) and OS (HR = 56.111, P = 0.026). Our findings suggest that p-4EBP1 may serve as a funnel factor that converge the upstream proliferative oncogenic signals. Effective inhibition of the pathways responsible for 4E-BP1 phosphorylation might be a useful strategy to improve the outcome of Xp11.2 RCC patients.

Mycobacterium avium subspecies paratuberculosis recombinant proteins modulate antimycobacterial functions of bovine macrophages

USDA-ARS?s Scientific Manuscript database

It has been shown that Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) activates the Mitogen Activated Protein Kinase (MAPK) p38 pathway, yet it is unclear which components of M. paratuberculosis are involved in the process. Therefore, a set of 42 M. paratuberculosis recombinan...

Upregulation of Nicotinic Acetylcholine Receptor alph4+beta2 through a Ligand-Independent PI3Kbeta Mechanism That Is Enhanced by TNFalpha and the Jak2/p38Mapk Pathways.

PubMed

Rogers, Scott W; Gahring, Lorise C

2015-01-01

High affinity nicotine-binding sites in the mammalian brain are neuronal nicotinic acetylcholine receptors (nAChR) assembled from at least alpha4 and beta2 subunits into pentameric ion channels. When exposed to ligands such as nicotine, these receptors respond by undergoing upregulation, a correlate of nicotine addiction. Upregulation can be measured using HEK293 (293) cells that stably express alpha4 and beta2 subunits using quantification of [3H]epibatidine ([3H]Eb) binding to measure mature receptors. Treatment of these cells with choline also produces upregulation through a hemicholinium3 (HC3)-sensitive (choline kinase) and an HC3-insensitive pathway which are both independent of the mechanism used by nicotine for upregulation. In both cases, upregulation is significantly enhanced by the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) which signals through its receptor Tnfr1 to activate p38Mapk. Here we report that the inhibition of class1 phosphoinositide 3-kinases isoform PI3Kbeta using the selective antagonist PI828 is alone sufficient to produce upregulation and enhance both nicotine and choline HC3-sensitive mediated upregulation. Further, these processes are impacted upon by an AG-490 sensitive Jak2-associated pathway. Both PI3Kbeta (negative) and Jak2 (positive) modulation of upregulation converge through p38Mapk and both overlap with TNFalpha enhancement of this process. Upregulation through the PI3Kbeta pathway did not require Akt. Collectively these findings support upregulation of endogenous alpha4beta2 as a balance among cellular signaling networks that are highly responsive to multiple environmental, inflammatory and metabolic agents. The findings also suggest how illness and metabolic stress could alter the expression of this important nicotinic receptor and novel avenues to intercede in modifying its expression.

CD40 engagement on dendritic cells induces cyclooxygenase-2 and EP2 receptor via p38 and ERK MAPKs.

PubMed

Harizi, Hedi; Limem, Ilef; Gualde, Norbert

2011-02-01

We have previously reported that cyclooxygenase (COX)-2-derived prostaglandin (PG)E2 critically regulates dendritic cell (DC) inflammatory phenotype and function through EP2/EP4 receptor subtypes. As genes activated by CD40 engagement are directly relevant to inflammation, we examined the effects of CD40 activation on inflammatory PGs in murine bone marrow-derived DC (mBM-DC). We showed for the first time that activation of mBM-DC with agonist anti-CD40 monoclonal antibody (anti-CD40 mAb) dose dependently induces the synthesis of significant amounts of PGE2 via inducible expression of COX-2 enzyme, as NS-398, a COX-2-selective inhibitor reduces this upregulation. In contrast to lipopolysaccharide, which upregulates mBM-DC surface levels of EP2 and EP4 receptors, CD40 crosslinking on mBM-DC increases EP2, but not EP4, receptor expression. Flow cytometry analysis and radioligand-binding assay showed that EP2 was the major EP receptor subtype, which binds to PGE2 at the surface of anti-CD40-activated mBM-DC. Upregulation of COX-2 and EP2 levels by CD40 engagement was accompanied by dose-dependent phosphorylation of p38 and ERK1/2 mitogen-activated protein kinase (MAPK) and was abrogated by inhibitors of both pathways. Collectively, we demonstrated that CD40 engagement on mBM-DC upregulates COX-2 and EP2 receptor expression through activation of p38 and ERK1/2 MAPK signaling. Triggering the PGE2/EP2 pathway by anti-CD40 mAb resulted on the induction of Th2 immune response. Thus, CD40-induced production of PGE2 by mBM-DC could represent a negative feedback mechanism involving EP2 receptor and limiting the propagation of Th1 responses. Blocking CD40 pathway may represent a novel therapeutic pathway of inhibiting COX-2-derived prostanoids in chronically inflamed tissues (that is, arthritis).

Effects of Curcumin on Tobacco Smoke-induced Hepatic MAPK Pathway Activation and Epithelial-Mesenchymal Transition In Vivo.

PubMed

Liang, Zhaofeng; Wu, Rui; Xie, Wei; Xie, Chunfeng; Wu, Jieshu; Geng, Shanshan; Li, Xiaoting; Zhu, Mingming; Zhu, Weiwei; Zhu, Jianyun; Huang, Cong; Ma, Xiao; Xu, Wenrong; Zhong, Caiyun; Han, Hongyu

2017-08-01

Tobacco smoke is a major risk factor for hepatic cancer. Epithelial-mesenchymal transition (EMT) induced by tobacco smoke is crucially involved in the initiation and development of cancer. Mitogen-activated protein kinase (MAPK) pathways play important roles in tobacco smoke-associated carcinogenesis including EMT process. The chemopreventive effect of curcumin supplementation against cancers has been reported. In this study, we investigated the effects of tobacco smoke on MAPK pathway activation and EMT alterations, and then the preventive effect of curcumin was examined in the liver of BALB/c mice. Our results indicated that exposure of mice to tobacco smoke for 12 weeks led to activation of ERK1/2, JNK, p38 and ERK5 pathways as well as activator protein-1 (AP-1) proteins in liver tissue. Exposure of mice to tobacco smoke reduced the hepatic mRNA and protein expression of the epithelial markers, while the hepatic mRNA and protein levels of the mesenchymal markers were increased. Treatment of curcumin effectively attenuated tobacco smoke-induced activation of ERK1/2 and JNK MAPK pathways, AP-1 proteins and EMT alterations in the mice liver. Our data suggested the protective effect of curcumin in tobacco smoke-triggered MAPK pathway activation and EMT in the liver of BALB/c mice, thus providing new insights into the chemoprevention of tobacco smoke-associated hepatic cancer. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Global functional analyses of cellular responses to pore-forming toxins.

PubMed

Kao, Cheng-Yuan; Los, Ferdinand C O; Huffman, Danielle L; Wachi, Shinichiro; Kloft, Nicole; Husmann, Matthias; Karabrahimi, Valbona; Schwartz, Jean-Louis; Bellier, Audrey; Ha, Christine; Sagong, Youn; Fan, Hui; Ghosh, Partho; Hsieh, Mindy; Hsu, Chih-Shen; Chen, Li; Aroian, Raffi V

2011-03-01

Here we present the first global functional analysis of cellular responses to pore-forming toxins (PFTs). PFTs are uniquely important bacterial virulence factors, comprising the single largest class of bacterial protein toxins and being important for the pathogenesis in humans of many Gram positive and Gram negative bacteria. Their mode of action is deceptively simple, poking holes in the plasma membrane of cells. The scattered studies to date of PFT-host cell interactions indicate a handful of genes are involved in cellular defenses to PFTs. How many genes are involved in cellular defenses against PFTs and how cellular defenses are coordinated are unknown. To address these questions, we performed the first genome-wide RNA interference (RNAi) screen for genes that, when knocked down, result in hypersensitivity to a PFT. This screen identifies 106 genes (∼0.5% of genome) in seven functional groups that protect Caenorhabditis elegans from PFT attack. Interactome analyses of these 106 genes suggest that two previously identified mitogen-activated protein kinase (MAPK) pathways, one (p38) studied in detail and the other (JNK) not, form a core PFT defense network. Additional microarray, real-time PCR, and functional studies reveal that the JNK MAPK pathway, but not the p38 MAPK pathway, is a key central regulator of PFT-induced transcriptional and functional responses. We find C. elegans activator protein 1 (AP-1; c-jun, c-fos) is a downstream target of the JNK-mediated PFT protection pathway, protects C. elegans against both small-pore and large-pore PFTs and protects human cells against a large-pore PFT. This in vivo RNAi genomic study of PFT responses proves that cellular commitment to PFT defenses is enormous, demonstrates the JNK MAPK pathway as a key regulator of transcriptionally-induced PFT defenses, and identifies AP-1 as the first cellular component broadly important for defense against large- and small-pore PFTs.

c-Raf/MEK/ERK pathway controls protein kinase C-mediated p70S6K activation in adult cardiac muscle cells.

PubMed

Iijima, Yoshihiro; Laser, Martin; Shiraishi, Hirokazu; Willey, Christopher D; Sundaravadivel, Balasubramanian; Xu, Lin; McDermott, Paul J; Kuppuswamy, Dhandapani

2002-06-21

p70S6 kinase (S6K1) plays a pivotal role in hypertrophic cardiac growth via ribosomal biogenesis. In pressure-overloaded myocardium, we show S6K1 activation accompanied by activation of protein kinase C (PKC), c-Raf, and mitogen-activated protein kinases (MAPKs). To explore the importance of the c-Raf/MAPK kinase (MEK)/MAPK pathway, we stimulated adult feline cardiomyocytes with 12-O-tetradecanoylphorbol-13-acetate (TPA), insulin, or forskolin to activate PKC, phosphatidylinositol-3-OH kinase, or protein kinase A (PKA), respectively. These treatments resulted in S6K1 activation with Thr-389 phosphorylation as well as mammalian target of rapamycin (mTOR) and S6 protein phosphorylation. Thr-421/Ser-424 phosphorylation of S6K1 was observed predominantly in TPA-treated cells. Dominant negative c-Raf expression or a MEK1/2 inhibitor (U0126) treatment showed a profound blocking effect only on the TPA-stimulated phosphorylation of S6K1 and mTOR. Whereas p38 MAPK inhibitors exhibited only partial effect, MAPK-phosphatase-3 expression significantly blocked the TPA-stimulated S6K1 and mTOR phosphorylation. Inhibition of mTOR with rapamycin blocked the Thr-389 but not the Thr-421/Ser-424 phosphorylation of S6K1. Therefore, during PKC activation, the c-Raf/MEK/extracellular signal-regulated kinase-1/2 (ERK1/2) pathway mediates both the Thr-421/Ser-424 and the Thr-389 phosphorylation in an mTOR-independent and -dependent manner, respectively. Together, our in vivo and in vitro studies indicate that the PKC/c-Raf/MEK/ERK pathway plays a major role in the S6K1 activation in hypertrophic cardiac growth.

Dusuqing granules (DSQ) suppress inflammation in Klebsiella pneumonia rat via NF-κB/MAPK signaling.

PubMed

Mei, Xue; Wang, Hao-Xun; Li, Jian-Sheng; Liu, Xiao-Hui; Lu, Xiao-Fan; Li, Ya; Zhang, Wei-Yu; Tian, Yan-Ge

2017-04-17

Dusuqing granules (DSQ) have been used in the treatment of bacterial pneumonia clinically, with remarkable benefits. This study was initiated to explore the effects of DSQ on pulmonary inflammation by regulating nuclear factor (NF)-κB/mitogen-activated protein kinase (MAPK) signaling in bacterial pneumonia rats. Rat model was duplicated with Klebsiella pneumonia by a one-time intratracheal injection. Rats were randomized into control, model, DSQ and levofloxacin (LVX) groups. After administrated with appropriate medicines for 7 days, lung tissues were harvested and prepared for pathological analysis, and interleukin (IL)-1, IL-6, monocyte chemotactic protein (MCP)-1and macrophage inflammatory protein (MIP)-2 detections. NF-κB mRNA was measured by real-time qPCR, and the phosphorylation and total proteins of P38MAPK, JNK46/54, ERK42/44 were determined by Western blotting. Marked pathological impairments were observed in model rats, whereas were improved in DSQ group. The cytokines levels, NF-κB mRNA expression and the phosphorylation of P38MAPK, JNK46/54 and ERK42/44 proteins were significantly higher in model group, and were significantly depressed in DSQ group. The protective effects of DSQ on Klebsiella pneumonia might be attributed to its inactivative effects of NF-κB/ MAPK pathway.

Procyanidin B2 induces Nrf2 translocation and glutathione S-transferase P1 expression via ERKs and p38-MAPK pathways and protect human colonic cells against oxidative stress.

PubMed

Rodríguez-Ramiro, Ildefonso; Ramos, Sonia; Bravo, Laura; Goya, Luis; Martín, Maria Ángeles

2012-10-01

Procyanidin B2 (PB2) is a naturally occurring flavonoid widely found in cocoa, red wine and grape juice. Recent studies have suggested that PB2 could protect against oxidative stress- and chemical-induced injury in colonic cells by modulating the endogenous cellular defence. However, the precise mechanism for this protection is not fully understood. Herein, we examined the effect of PB2 on the expression of one of the major antioxidant/detoxificant enzymes related to intestinal protection, the glutathione S-transferase P1 (GSTP1), and the molecular mechanisms involved. Human colonic Caco-2 cells were treated with PB2 at different times and enzymatic activity, and mRNA and protein levels of GSTP1 were evaluated. The nuclear translocation of the transcription factor NF-erythroid 2-related factor (Nrf2) and the phosphorylation states of specific proteins central to intracellular signalling cascades were also investigated. PB2 induced the expression and activity of GSTP1 and the nuclear translocation of Nrf2. Interestingly, two important signalling proteins involved in Nrf2 translocation, the extracellular signal-regulated protein kinases (ERKs) and the p38 mitogen-activated protein kinase (MAPK) were also activated. Further experiments with specific inhibitors of both pathways confirmed their critical role in the beneficial effects induced by PB2. The present results show that PB2 protects against oxidative injury in colonic cells and up-regulate the expression of GSTP1 via a mechanism that involves ERK and p38 MAPK activation and Nrf2 translocation. These results provide a molecular basis for the potential contribution of PB2 in the prevention of oxidative stress-related intestinal injury and gut pathologies.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheon, Soyoung; Song, Seok Bean; Jung, Minkyung

2008-09-12

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

The dual-specificity phosphatase MKP-1 limits the cardiac hypertrophic response in vitro and in vivo.

PubMed

Bueno, O F; De Windt, L J; Lim, H W; Tymitz, K M; Witt, S A; Kimball, T R; Molkentin, J D

2001-01-19

Mitogen-activated protein kinase (MAPK) signaling pathways are important regulators of cell growth, proliferation, and stress responsiveness. A family of dual-specificity MAP kinase phosphatases (MKPs) act as critical counteracting factors that directly regulate the magnitude and duration of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) activation. Here we show that constitutive expression of MKP-1 in cultured primary cardiomyocytes using adenovirus-mediated gene transfer blocked the activation of p38, JNK1/2, and ERK1/2 and prevented agonist-induced hypertrophy. Transgenic mice expressing physiological levels of MKP-1 in the heart showed (1) no activation of p38, JNK1/2, or ERK1/2; (2) diminished developmental myocardial growth; and (3) attenuated hypertrophy in response to aortic banding and catecholamine infusion. These results provide further evidence implicating MAPK signaling factors as obligate regulators of cardiac growth and hypertrophy and demonstrate the importance of dual-specificity phosphatases as counterbalancing regulatory factors in the heart.

Phosphorylated 4EBP1 is associated with tumor progression and poor prognosis in Xp11.2 translocation renal cell carcinoma

PubMed Central

Qu, Yuanyuan; Zhao, Rui; Wang, Hongkai; Chang, Kun; Yang, Xiaoqun; Zhou, Xiaoyan; Dai, Bo; Zhu, Yao; Shi, Guohai; Zhang, Hailiang; Ye, Dingwei

2016-01-01

Two main signaling pathways, PI3K-AKT-mTOR and RAS-MAPK, are involved in transmitting the proliferative signals which play critical roles in human cancers. However, the functions of these pathways in Xp11.2 RCC remain undefined. This study aimed to explore the expression of mTOR and MAPK cascades in Xp11.2 RCC and to assess the prognostic significance of proteins evaluated. Immunohistochemistry was performed to evaluate the expression of 4EBP1, p-4EBP1, p-mTOR, p-S6K and p-MAPK in 36 adult Xp11.2 RCC patients who were confirmed by FISH assay. Cox regression models were used to evaluate the prognostic value of all covariates. Among 36 assessed patients, 14 (38.9%), 26 (72.2%), 16 (44.4%), 19 (52.8%), and 9 (25.0%) patients showed high expression of 4EBP1, p-4EBP1, p-mTOR, p-S6K, and p-MAPK, respectively. We noted that p-4EBP1 expression was significantly correlated with lymph node metastases (P = 0.027). Multivariate analysis showed that high p-4EBP1 expression was an independent adverse prognostic factor for both PFS (HR = 33.750, P = 0.017) and OS (HR = 56.111, P = 0.026). Our findings suggest that p-4EBP1 may serve as a funnel factor that converge the upstream proliferative oncogenic signals. Effective inhibition of the pathways responsible for 4E-BP1 phosphorylation might be a useful strategy to improve the outcome of Xp11.2 RCC patients. PMID:27026382

Galectin-9 exhibits anti-myeloma activity through JNK and p38 MAP kinase pathways.

PubMed

Kobayashi, T; Kuroda, J; Ashihara, E; Oomizu, S; Terui, Y; Taniyama, A; Adachi, S; Takagi, T; Yamamoto, M; Sasaki, N; Horiike, S; Hatake, K; Yamauchi, A; Hirashima, M; Taniwaki, M

2010-04-01

Galectins constitute a family of lectins that specifically exhibit the affinity for beta-galactosides and modulate various biological events. Galectin-9 is a tandem-repeat type galectin with two carbohydrate recognition domains and has recently been shown to have an anti-proliferative effect on cancer cells. We investigated the effect of recombinant protease-resistant galectin-9 (hGal9) on multiple myeloma (MM). In vitro, hGal9 inhibited the cell proliferation of five myeloma cell lines examined, including a bortezomib-resistant subcell line, with IC(50) between 75.1 and 280.0 nM, and this effect was mediated by the induction of apoptosis with the activation of caspase-8, -9, and -3. hGal9-activated Jun NH(2)-terminal kinase (JNK) and p38 MAPK signaling pathways followed by H2AX phosphorylation. Importantly, the inhibition of either JNK or p38 MAPK partly inhibited the anti-proliferative effect of hGal9, indicating the crucial role of these pathways in the anti-MM effect of hGal9. hGal9 also induced cell death in patient-derived myeloma cells, some with poor-risk factors, such as chromosomal deletion of 13q or translocation t(4;14)(p16;q32). Finally, hGal9 potently inhibited the growth of human myeloma cells xenografted in nude mice. These suggest that hGal9 is a new therapeutic target for MM that may overcome resistance to conventional chemotherapy.

Pseudomonas aeruginosa elastase causes transient disruption of tight junctions and downregulation of PAR-2 in human nasal epithelial cells.

PubMed

Nomura, Kazuaki; Obata, Kazufumi; Keira, Takashi; Miyata, Ryo; Hirakawa, Satoshi; Takano, Ken-ichi; Kohno, Takayuki; Sawada, Norimasa; Himi, Tetsuo; Kojima, Takashi

2014-02-18

Pseudomonas aeruginosa causes chronic respiratory disease, and the elastase enzyme that it produces increases the permeability of airway epithelial cells owing to the disruption of tight junctions. P. aeruginosa is also implicated in prolonged chronic rhinosinusitis. However, the effects of P. aeruginosa elastase (PE) against the barrier formed by human nasal epithelial cells (HNECs) remain unknown. To investigate the mechanisms involved in the disruption of tight junctions by PE in HNECs, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were used. The hTERT-HNECs were pretreated with inhibitors of various signal transduction pathways, PKC, MAPK, p38MAPK, PI3K, JNK, NF-κB, EGF receptor, proteasome, COX1 and COX2 before treatment with PE. Some cells were pretreated with siRNA and agonist of protease activated receptor-2 (PAR-2) before treatment with PE. Expression and structures of tight junctions were determined by Western blotting, real-time PCR, immunostaining and freeze-fracture. Transepithelial electrical resistance (TER) was examined as the epithelial barrier function. PE treatment transiently disrupted the epithelial barrier and downregulated the transmembrane proteins claudin-1 and -4, occludin, and tricellulin, but not the scaffold PDZ-expression proteins ZO-1 and -2 and adherens junction proteins E-cadherin and β-catenin. The transient downregulation of tight junction proteins was controlled via distinct signal transduction pathways such as the PKC, MAPK, PI3K, p38 MAPK, JNK, COX-1 and -2, and NF-κB pathways. Furthermore, treatment with PE transiently decreased PAR-2 expression, which also regulated the expression of the tight junction proteins. Treatment with a PAR-2 agonist prevented the downregulation of the tight junction proteins after PE treatment in HNECs. PE transiently disrupts tight junctions in HNECs and downregulates PAR-2. The transient disruption of tight junctions by PE might occur repeatedly during chronic rhinosinusitis.

Pseudomonas aeruginosa elastase causes transient disruption of tight junctions and downregulation of PAR-2 in human nasal epithelial cells

PubMed Central

2014-01-01

Background Pseudomonas aeruginosa causes chronic respiratory disease, and the elastase enzyme that it produces increases the permeability of airway epithelial cells owing to the disruption of tight junctions. P. aeruginosa is also implicated in prolonged chronic rhinosinusitis. However, the effects of P. aeruginosa elastase (PE) against the barrier formed by human nasal epithelial cells (HNECs) remain unknown. Methods To investigate the mechanisms involved in the disruption of tight junctions by PE in HNECs, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were used. The hTERT-HNECs were pretreated with inhibitors of various signal transduction pathways, PKC, MAPK, p38MAPK, PI3K, JNK, NF-κB, EGF receptor, proteasome, COX1 and COX2 before treatment with PE. Some cells were pretreated with siRNA and agonist of protease activated receptor-2 (PAR-2) before treatment with PE. Expression and structures of tight junctions were determined by Western blotting, real-time PCR, immunostaining and freeze-fracture. Transepithelial electrical resistance (TER) was examined as the epithelial barrier function. Results PE treatment transiently disrupted the epithelial barrier and downregulated the transmembrane proteins claudin-1 and -4, occludin, and tricellulin, but not the scaffold PDZ-expression proteins ZO-1 and -2 and adherens junction proteins E-cadherin and β-catenin. The transient downregulation of tight junction proteins was controlled via distinct signal transduction pathways such as the PKC, MAPK, PI3K, p38 MAPK, JNK, COX-1 and -2, and NF-κB pathways. Furthermore, treatment with PE transiently decreased PAR-2 expression, which also regulated the expression of the tight junction proteins. Treatment with a PAR-2 agonist prevented the downregulation of the tight junction proteins after PE treatment in HNECs. Conclusions PE transiently disrupts tight junctions in HNECs and downregulates PAR-2. The transient disruption of tight junctions by PE might occur repeatedly during chronic rhinosinusitis. PMID:24548792

Halofuginone inhibits Smad3 phosphorylation via the PI3K/Akt and MAPK/ERK pathways in muscle cells: Effect on myotube fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roffe, Suzy; Hagai, Yosey; Institute of Animal Sciences, Volcani Center, Bet Dagan 50250

2010-04-01

Halofuginone, a novel inhibitor of Smad3 phosphorylation, has been shown to inhibit muscle fibrosis and to improve cardiac and skeletal muscle functions in the mdx mouse model of Duchenne muscular dystrophy. Here, we demonstrate that halofuginone promotes the phosphorylation of Akt and mitogen-activated protein kinase (MAPK) family members in a C2 muscle cell line and in primary myoblasts derived from wild-type and mdx mice diaphragms. Halofuginone enhanced the association of phosphorylated Akt and MAPK/extracellular signal-regulated protein kinase (ERK) with the non-phosphorylated form of Smad3, accompanied by a reduction in Smad3 phosphorylation levels. This reduction was reversed by inhibitors of themore » phosphoinositide 3'-kinase/Akt (PI3K/Akt) and MAPK/ERK pathways, suggesting their specific role in mediating halofuginone's inhibitory effect on Smad3 phosphorylation. Halofuginone enhanced Akt, MAPK/ERK and p38 MAPK phosphorylation and inhibited Smad3 phosphorylation in myotubes, all of which are crucial for myotube fusion. In addition, halofuginone increased the association Akt and MAPK/ERK with Smad3. As a consequence, halofuginone promoted myotube fusion, as reflected by an increased percentage of C2 and mdx myotubes containing high numbers of nuclei, and this was reversed by specific inhibitors of the PI3K and MAPK/ERK pathways. Together, the data suggest a role, either direct or via inhibition of Smad3 phosphorylation, for Akt or MAPK/ERK in halofuginone-enhanced myotube fusion, a feature which is crucial to improving muscle function in muscular dystrophies.« less

The anti-inflammatory mechanism of heme oxygenase-1 induced by hemin in primary rat alveolar macrophages.

PubMed

Hualin, Chen; Wenli, Xu; Dapeng, Liu; Xijing, Li; Xiuhua, Pan; Qingfeng, Pang

2012-06-01

Alveolar macrophages (AMs) can initiate lung inflammation by producing pro-inflammatory cytokines and chemokines, but they participate actively in the prevention of inflammation during acute lung injury (ALI). Heme oxygenase-1 (HO-1) is mainly expressed in AMs and has anti-inflammatory properties in ALI, but the anti-inflammatory mechanisms of HO-1 are largely unknown. In this study, AMs were treated with saline, LPS (1 μg/ml), hemin (10 μM), zinc protoporphyrin (ZnPP; 10 μM, 1 h prior to LPS and hemin), SB203580 (10 μM, 1 h prior to LPS and hemin), or their combination up to 24 h. The specific HO-1 inhibitor ZnPP and SB203580 were used to inhibit the effects of HO-1 and the phosphorylated p38 mitogen-activated protein kinase (MAPK), respectively. The protein levels of HO-1 and p38 MAPK were analyzed by western blotting; arginase activity was measured in lysates obtained from cultured cells; nitric oxide production in the extracellular medium of AMs cultured for 24 h was monitored by assessing nitrite levels; the phagocytic ability of macrophage was measured by neutral red uptake. IL-10 of culture supernatants in AMs was determined by enzyme-linked immunosorbent assay. The results indicated that HO-1 induced by hemin increased arginase activity and phagocytic ability and decreased iNOS activity via p38 MAPK pathway in primary rat AMs. These changes and p38 MAPK may be the anti-inflammatory mechanism of HO-1 induced by hemin in primary rat AMs.

Recombinant tissue plasminogen activator enhances microparticle release from mouse brain-derived endothelial cells through plasmin.

PubMed

Garraud, Marie; Khacef, Kahina; Vion, Anne-Clémence; Leconte, Claire; Yin, Min; Renard, Jean-Marie; Marchand-Leroux, Catherine; Boulanger, Chantal M; Margaill, Isabelle; Beray-Berthat, Virginie

2016-11-15

Thrombolysis with recombinant tissue plasminogen activator (rt-PA) is currently the only approved pharmacological strategy for acute ischemic stroke. However, rt-PA exhibits vascular toxicity mainly due to endothelial damage. To investigate the mechanisms underlying rt-PA-induced endothelial alterations, we assessed the role of rt-PA in the generation of endothelial microparticles (EMPs), emerging biological markers and effectors of endothelial dysfunction. The mouse brain-derived endothelial cell line bEnd.3 was used. Cells were treated with rt-PA at 20, 40 or 80μg/ml for 15 or 24h, and EMPs were quantified in the culture media using Annexin-V staining coupled with flow cytometry. Rt-PA enhanced EMP release from bEnd.3 cells with a maximal increase at the 40μg/ml dose for 24h (+78% compared to controls). Using tranexamic acid and aprotinin we demonstrated that plasmin is responsible for rt-PA-induced EMP release. The p38 MAPK inhibitor SB203580 and the poly(ADP-ribose)polymerase (PARP) inhibitor PJ34 also reduced rt-PA-induced EMP production, suggesting that p38 MAPK and PARP are downstream intracellular effectors of rt-PA/plasmin. Rt-PA also altered through plasmin the morphology and the confluence of bEnd.3 cells. By contrast, these changes did not implicate p38 MAPK and PARP. This study demonstrates that rt-PA induces the production of microparticles by cerebral endothelial cells, through plasmin, p38 MAPK and PARP pathways. Determining the phenotype of these EMPs to clarify their role on the endothelium in ischemic conditions could thus be of particular interest. Copyright © 2016 Elsevier B.V. All rights reserved.

Protective effect of geraniol inhibits inflammatory response, oxidative stress and apoptosis in traumatic injury of the spinal cord through modulation of NF-κB and p38 MAPK.

PubMed

Wang, Jiansheng; Su, Baishan; Zhu, Hongbin; Chen, Chao; Zhao, Gang

2016-12-01

Geraniol is a type of monoterpenoid with a rose scent and a slightly sweet flavor. It is found in the volatile oil of various plants, and has anti-inflammatory and anti-oxidant effects. The present study aimed to investigate the protective effect of geraniol in inhibiting the inflammatory response, oxidative stress and apoptosis in traumatic spinal cord injury (SCI), as well as to analyze the mechanism underlying its effect. Adult male Sprague-Dawley rats were induced to traumatic SCI through a surgical procedure and were defined as the SCI model group. SCI or normal rats were then administered 250 mg/kg/day geraniol for 4 weeks. The Basso, Beattie and Bresnahan (BBB) test and the spinal cord water content were used to analyze the effect of geraniol against traumatic SCI in rats. The inflammatory response, oxidative stress, and caspase-9 and -3 activities were measured using commercial ELISA kits. In addition, the associated mechanism was analyzed, using western blot analysis to determine the protein expression levels of nuclear factor (NF)-κB and p38 mitogen-activated protein kinase (MAPK). The results of the present study demonstrated that BBB scores were significantly increased and the spinal cord water content was significantly inhibited in SCI rats after 3 weeks of geraniol treatment. Furthermore, the inflammatory response, oxidative stress, and the caspase-9 and -3 activities were significantly suppressed upon treatment with geraniol. Finally, the mechanism of geraniol against traumatic SCI downregulated the NF-κB and p38 MAPK pathways in SCI rats. Therefore, the protective effect of geraniol is suggested to inhibit the inflammatory response, oxidative stress and apoptosis in traumatic SCI through the modulation of NF-κB and p38 MAPK.

Cigarette smoke and α,β-unsaturated aldehydes elicit VEGF release through the p38 MAPK pathway in human airway smooth muscle cells and lung fibroblasts

PubMed Central

Volpi, Giorgia; Facchinetti, Fabrizio; Moretto, Nadia; Civelli, Maurizio; Patacchini, Riccardo

2011-01-01

BACKGROUND AND PURPOSE Vascular endothelial growth factor (VEGF) is an angiogenic factor known to be elevated in the sputum of asymptomatic smokers as well as smokers with bronchitis type of chronic obstructive pulmonary disease. The aim of this study was to investigate whether acute exposure to cigarette smoke extract altered VEGF production in lung parenchymal cells. EXPERIMENTAL APPROACH We exposed human airway smooth muscle cells (ASMC), normal human lung fibroblasts (NHLF) and small airways epithelial cells (SAEC) to aqueous cigarette smoke extract (CSE) in order to investigate the effect of cigarette smoke on VEGF expression and release. KEY RESULTS Vascular endothelial growth factor release was elevated by sub-toxic concentrations of CSE in both ASMC and NHLF, but not in SAEC. CSE-evoked VEGF release was mimicked by its component acrolein at concentrations (10–100 µM) found in CSE, and prevented by the antioxidant and α,β-unsaturated aldehyde scavenger, N-acetylcysteine (NAC). Both CSE and acrolein (30 µM) induced VEGF mRNA expression in ASMC cultures, suggesting an effect at transcriptional level. Crotonaldehyde and 4-hydroxy-2-nonenal, an endogenous α,β-unsaturated aldehyde, stimulated VEGF release, as did H2O2. CSE-evoked VEGF release was accompanied by rapid and lasting phosphorylation of p38 MAPK (mitogen-activated protein kinase), which was abolished by NAC and mimicked by acrolein. Both CSE- and acrolein-evoked VEGF release were blocked by selective inhibition of p38 MAPK signalling. CONCLUSIONS AND IMPLICATIONS α,β-Unsaturated aldehydes and possibly reactive oxygen species contained in cigarette smoke stimulate VEGF expression and release from pulmonary cells through p38 MAPK signalling. PMID:21306579

Involvement of nuclear factor {kappa}B in platelet CD40 signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hachem, Ahmed; Yacoub, Daniel; Centre Hospitalier Universite de Montreal, 264 boul. Rene-Levesque est, Montreal, Quebec, Canada H2X 1P1

Highlights: Black-Right-Pointing-Pointer sCD40L induces TRAF2 association to CD40 and NF-{kappa}B activation in platelets. Black-Right-Pointing-Pointer I{kappa}B{alpha} phosphorylation downstream of CD40L/CD40 signaling is independent of p38 MAPK phosphorylation. Black-Right-Pointing-Pointer I{kappa}B{alpha} is required for sCD40L-induced platelet activation and potentiation of aggregation. -- Abstract: CD40 ligand (CD40L) is a thrombo-inflammatory molecule that predicts cardiovascular events. Platelets constitute the major source of soluble CD40L (sCD40L), which has been shown to potentiate platelet activation and aggregation, in a CD40-dependent manner, via p38 mitogen activated protein kinase (MAPK) and Rac1 signaling. In many cells, the CD40L/CD40 dyad also induces activation of nuclear factor kappa B (NF-{kappa}B). Givenmore » that platelets contain NF-{kappa}B, we hypothesized that it may be involved in platelet CD40 signaling and function. In human platelets, sCD40L induces association of CD40 with its adaptor protein the tumor necrosis factor receptor associated factor 2 and triggers phosphorylation of I{kappa}B{alpha}, which are abolished by CD40L blockade. Inhibition of I{kappa}B{alpha} phosphorylation reverses sCD40L-induced I{kappa}B{alpha} phosphorylation without affecting p38 MAPK phosphorylation. On the other hand, inhibition of p38 MAPK phosphorylation has no effect on I{kappa}B{alpha} phosphorylation, indicating a divergence in the signaling pathway originating from CD40 upon its ligation. In functional studies, inhibition of I{kappa}B{alpha} phosphorylation reverses sCD40L-induced platelet activation and potentiation of platelet aggregation in response to a sub-threshold concentration of collagen. This study demonstrates that the sCD40L/CD40 axis triggers NF-{kappa}B activation in platelets. This signaling pathway plays a critical role in platelet activation and aggregation upon sCD40L stimulation and may represent an important target against thrombo-inflammatory disorders.« less

SL4, a chalcone-based compound, induces apoptosis in human cancer cells by activation of the ROS/MAPK signalling pathway.

PubMed

Wang, L-H; Li, H-H; Li, M; Wang, S; Jiang, X-R; Li, Y; Ping, G-F; Cao, Q; Liu, X; Fang, W-H; Chen, G-L; Yang, J-Y; Wu, C-F

2015-12-01

SL4, a chalcone-based compound, exhibits clearly inhibitory effects on HIF-1 and has been shown to effectively suppress tumour invasion and angiogenesis in vitro and in vivo. Here, studies were conducted to determine SL4's anti-apoptotic effects and its underlying mechanisms, in human cancer cells. Cytotoxicity, apoptotic induction and its involved mechanisms of SL4 were investigated using normal cells, cancer cells and mouse xenograft models. The role of reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK) signalling in SL4-induced apoptosis was explored by manipulating specific scavenger or signalling inhibitors, in cultured cells. SL4 significantly inhibited cell population growth of human cancer cell lines but exhibited lower cytotoxicity against normal cells. In addition, SL4 effectively induced apoptosis of Hep3B and MDA-MB-435 cells by activating procaspase-8, -9 and -3, and down-regulating expression levels of XIAP, but did not affect HIF-1 apoptosis-related targets, Survivin and Bcl-XL. Further study showed that SL4 also reduced mitochondrial membrane potential and promoted generation of ROS. ROS generation and apoptotic induction by SL4 were blocked by NAC, a scavenger of ROS, suggesting SL4-induced apoptosis via ROS accumulation. We also found that MAPKs, JNK and p38, but not ERK1/2, to be critical mediators in SL4-induced apoptosis. SP600125 and SB203580, specific inhibitors of JNK kinase and p38 kinase, significantly retarded apoptosis induced by SL4. Moreover, anti-oxidant NAC blocked activation of JNK and p38 induced by SL4, indicating that ROS may act as upstream signalling of JNK and p38 activation. It is noteworthy that animal studies revealed dramatic reduction (49%) in tumour volume after 11 days SL4 treatment. These data demonstrate that SL4 induced apoptosis in human cancer cells through activation of the ROS/MAPK signalling pathway, suggesting that it may be a novel lead compound, as a cancer drug candidate, with polypharmacological characteristics. © 2015 John Wiley & Sons Ltd.

Gypenoside IX Suppresses p38 MAPK/Akt/NFκB Signaling Pathway Activation and Inflammatory Responses in Astrocytes Stimulated by Proinflammatory Mediators.

PubMed

Wang, Xiaoshuang; Yang, Liu; Yang, Li; Xing, Faping; Yang, Hua; Qin, Liyue; Lan, Yunyi; Wu, Hui; Zhang, Beibei; Shi, Hailian; Lu, Cheng; Huang, Fei; Wu, Xiaojun; Wang, Zhengtao

2017-12-01

Gypenoside IX (GP IX) is a pure compound isolated from Panax notoginseng. Gypenosides have been implicated to benefit the recovery of enormous neurological disorders. By suppressing the activation of astrocytes, gypenosides can improve the cognitive impairment. However, so far, little is known about whether GP IX could restrain the inflammatory responses in astrocytes or reactive astrogliosis. In present study, the anti-inflammatory effects of GP IX were investigated in reactive astrocytes induced by proinflammatory mediators both in vitro and in vivo. GP IX significantly reduced the production of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) at either protein or mRNA level in glial cell line C6 cells stimulated by lipopolysaccharide (LPS)/TNF-α combination. It also alleviated the astrogliosis and decreased the production of inflammatory mediators in brain cortex of LPS-treated mice. Further study disclosed that GP IX inhibited nuclear translocation of nuclear factor kappa B (NFκB) and reduced its transcriptional activity. Meanwhile, GP IX significantly attenuated the phosphorylation of NFκB, inhibitor of kappa B (IκB), Akt, and p38 mitogen-activated protein kinase (MAPK) under inflammatory conditions both in vitro and in vivo. These findings indicated that GP IX might suppress reactive astrogliosis by suppressing Akt/p38 MAPK/NFκB signaling pathways. And GP IX might be a promising drug candidate or prodrug for the therapy of neuroinflammatory disorders characterized with reactive astrogliosis.

Cholesterol depletion in cell membranes of human airway epithelial cells suppresses MUC5AC gene expression.

PubMed

Song, Kee Jae; Kim, Na Hyun; Lee, Gi Bong; Kim, Ji Hoon; Kwon, Jin Ho; Kim, Kyung-Su

2013-05-01

If cholesterol in the cell membrane is depleted by treating cells with methyl-β-cyclodextrin (MβCD), the activities of transmembrane receptors are altered in a cell-specific and/or receptor-specific manner. The proinflammatory cytokines, IL-1β is potent inducers of MUC5AC mRNA and protein synthesis in human airway epithelial cells. Cells activated by IL-1β showed increased phosphorylation of extracellular signal regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK). Thus, we investigated the effects of cholesterol depletion on the expression of MUC5AC in human airway epithelial cells and whether these alterations to MUC5AC expression were related to MAPK activity. After NCI-H292 cells were pretreated with 1% MβCD before adding IL-1β for 24 hours, MUC5AC mRNA expression was determined by reverse transcription- polymerase chain reaction (RT-PCR) and real time-PCR. Cholesterol depletion by MβCD was measured by modified microenzymatic fluorescence assay and filipin staining. The phosphorylation of IL-1 receptor, ERK and p38 MAPK, was analyzed by western blot. Cholesterol in the cell membrane was significantly depleted by treatment with MβCD on cells. IL-1β-induced MUC5AC mRNA expression was decreased by MβCD and this decrease occurred IL-1-receptor- specifically. Moreover, we have shown that MβCD suppressed the activation of ERK1/2 and p38 MAPK in cells activated with IL-1β. This result suggests that MβCD-mediated suppression of IL-1β-induced MUC5AC mRNA operated via the ERK- and p38 MAPK-dependent pathway. Cholesterol depletion in NCI-H292 cell membrane may be considered an anti-hypersecretory method since it effectively inhibits mucus secretion of respiratory epithelial cells.

The synergistic antitumor activity of arsenic trioxide and vitamin K2 in HL-60 cells involves increased ROS generation and regulation of the ROS-dependent MAPK signaling pathway.

PubMed

Qu, Hui; Tong, Danan; Zhang, Yanqing; Kang, Kai; Zhang, Yuling; Chen, Lan; Ren, Lihong

2013-10-01

The aim of this study was to investigate the synergistic anticancer effects of arsenic trioxide (ATO) and vitamin K2 (VK2) in HL-60 cells, and elucidate the potential mechanisms. HL-60 cells were exposed to ATO and VK2, either alone or in combination. Cell proliferation and apoptosis were assessed. The combination index (CI) method was used to evaluate whether the action of the drug combination was synergistic, additive or antagonistic. Reactive oxygen species (ROS) and the mitogen-activated protein kinase (MAPK) signaling pathway were also studied, to provide insight into potential mechanisms. The results showed that combining ATO with VK2 significantly inhibited HL-60 cell growth more than either agent alone, indicating a synergistic effect with CI < 1. Annexin V staining demonstrated that the inhibition of cell growth by the drug combination was mediated through an increase in apoptosis; this was supported by examination of caspase-3 and caspase-9 with Western blot assays. Furthermore, induction of ROS, and phosphorylation and activation of the JNK and p38 (but not ERK1/2) pathways, was observed in cells administered the drug combination. Prior treatment with the antioxidant, N-acetylcysteine, partly blocked the apoptosis and expression of caspase-3 induced by the drug combination; apoptosis and expression of caspase-3 were also reversed by inhibitors of JNK or p38. These results suggest that ATO and VK2 act synergistically to increase HL-60 cell apoptosis, through ROS generation and regulation of the MAPK signaling pathway.

Effects of PTHrP on expression of MMP9 and MMP13 in sika deer antler chondrocytes.

PubMed

Wang, Shou-Tang; Gao, Ying-Jie; Duan, Cui-Cui; Li, Dang-Dang; Tian, Xue-Chao; Zhang, Qiao-Ling; Guo, Bin; Yue, Zhan-Peng

2013-12-01

Deer antlers are the only mammalian appendages to display an annual cycle of full regeneration. However, little is known about the molecular mechanisms of antler regeneration. Our previous study has demonstrated that parathyroid hormone-related peptide (PTHrP) can promote proliferation of antler chondrocytes and inhibit its differentiation, but the mechanism underlying such regulation is not fully understood. We have determined the role of PTHrP on the mRNA expression of matrix metalloproteinase-9 (MMP9) and MMP13 in the antler chondrocytes. The possible pathways that transduce PTHrP effects were examined. In situ hybridization showed that MMP9 and MMP13 were mainly localized in the dermal fibroblasts, perichondrium, and cartilage in the sika deer antler, of which MMP9 and MMP13 were highly expressed in the chondrocytes. Exogenous PTHrP could inhibit the expression of MMP9 and MMP13 in the antler chondrocytes. The inhibitory effect of PTHrP on MMP9 was abolished by JNK inhibitor, SP600125, while P38MAPK inhibitor SB203850 and PKC inhibitor GF109203X could rescue the inhibitory effect of PTHrP on MMP13. The results suggest that PTHrP can inhibit MMP9 expression by JNK signaling pathway and MMP13 expression by p38MAPK and PKC signaling pathways in the antler chondrocytes. Thus PTHrP is involved in the control of antler chondrocytes maturation and cartilage matrix degradation. © 2013 International Federation for Cell Biology.

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

Blockade of CD26 signaling inhibits human osteoclast development.

PubMed

Nishida, Hiroko; Suzuki, Hiroshi; Madokoro, Hiroko; Hayashi, Mutsumi; Morimoto, Chikao; Sakamoto, Michiie; Yamada, Taketo

2014-11-01

Bone remodeling is maintained by the delicate balance between osteoblasts (OBs) and osteoclasts (OCs). However, the role of CD26 in regulating bone remodeling has not yet been characterized. We herein show that CD26 is preferentially expressed on normal human OCs and is intensely expressed on activated human OCs in osteolytic bone alterations. Macrophage-colony stimulating factor (M-CSF) and soluble receptor activator of NF-κB ligand (sRANKL) induced human OC differentiation, in association with CD26 expression on monocyte-macrophage lineage cells. CD26 expression was accompanied by increased phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), which is crucial for early human OC differentiation. The humanized anti-CD26 monoclonal antibody, huCD26mAb, impaired the formation and function of tartrate-resistant acid phosphatase (TRAP)/CD26 positive multi-nucleated (nuclei > 3) OCs with maturation in the manner of dose-dependency. It was revealed that huCD26mAb inhibits early OC differentiation via the inactivation of MKK3/6, p38 MAPK and subsequent dephosphorylation of microphthalmia-associated transcription factor (mi/Mitf). These inhibitions occur immediately after RANKL binds to RANK on the human OC precursor cells and were demonstrated using the OC functional assays. huCD26mAb subsequently impaired OC maturation and bone resorption by suppressing the expression of TRAP and OC fusion proteins. In addition, p38 MAPK inhibitor also strongly inhibited OC formation and function. Our results suggest that the blockade of CD26 signaling impairs the development of human functional OCs by inhibiting p38 MAPK-mi/Mitf phosphorylation pathway and that targeting human OCs with huCD26mAb may have therapeutic potential for the treatment of osteolytic lesions following metastasis to alleviate bone destruction and reduce total skeletal-related events (SREs). © 2014 American Society for Bone and Mineral Research.

Trimethyltin-Induced Microglial Activation via NADPH Oxidase and MAPKs Pathway in BV-2 Microglial Cells.

PubMed

Kim, Da Jung; Kim, Yong Sik

2015-01-01

Trimethyltin (TMT) is known as a potent neurotoxicant that causes neuronal cell death and neuroinflammation, particularly in the hippocampus. Microglial activation is one of the prominent pathological features of TMT neurotoxicity. Nevertheless, it remains unclear how microglial activation occurs in TMT intoxication. In this study, we aimed to investigate the signaling pathways in TMT-induced microglial activation using BV-2 murine microglial cells. Our results revealed that TMT generates reactive oxygen species (ROS) and increases the expression of CD11b and nuclear factor-κB- (NF-κB-) mediated nitric oxide (NO) and tumor necrosis factor- (TNF-) α in BV-2 cells. We also observed that NF-κB activation was controlled by p38 and JNK phosphorylation. Moreover, TMT-induced ROS generation occurred via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in BV-2 cells. Interestingly, treatment with the NADPH oxidase inhibitor apocynin significantly suppressed p38 and JNK phosphorylation and NF-κB activation and ultimately the production of proinflammatory mediators upon TMT exposure. These findings indicate that NADPH oxidase-dependent ROS generation activated p38 and JNK mitogen-activated protein kinases (MAPKs), which then stimulated NF-κB to release proinflammatory mediators in the TMT-treated BV-2 cells.

Trimethyltin-Induced Microglial Activation via NADPH Oxidase and MAPKs Pathway in BV-2 Microglial Cells

PubMed Central

Kim, Da Jung; Kim, Yong Sik

2015-01-01

Trimethyltin (TMT) is known as a potent neurotoxicant that causes neuronal cell death and neuroinflammation, particularly in the hippocampus. Microglial activation is one of the prominent pathological features of TMT neurotoxicity. Nevertheless, it remains unclear how microglial activation occurs in TMT intoxication. In this study, we aimed to investigate the signaling pathways in TMT-induced microglial activation using BV-2 murine microglial cells. Our results revealed that TMT generates reactive oxygen species (ROS) and increases the expression of CD11b and nuclear factor-κB- (NF-κB-) mediated nitric oxide (NO) and tumor necrosis factor- (TNF-) α in BV-2 cells. We also observed that NF-κB activation was controlled by p38 and JNK phosphorylation. Moreover, TMT-induced ROS generation occurred via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in BV-2 cells. Interestingly, treatment with the NADPH oxidase inhibitor apocynin significantly suppressed p38 and JNK phosphorylation and NF-κB activation and ultimately the production of proinflammatory mediators upon TMT exposure. These findings indicate that NADPH oxidase-dependent ROS generation activated p38 and JNK mitogen-activated protein kinases (MAPKs), which then stimulated NF-κB to release proinflammatory mediators in the TMT-treated BV-2 cells. PMID:26221064

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.

Protective activity of salidroside against ethanol-induced gastric ulcer via the MAPK/NF-κB pathway in vivo and in vitro.

PubMed

Chang, Xiayun; Luo, Fen; Jiang, Wenjiao; Zhu, Lingpeng; Gao, Jin; He, He; Wei, Tingting; Gong, Shilin; Yan, Tianhua

2015-09-01

Salidroside (Sal) is a traditional Chinese medicine with various pharmacological effects. The present study aimed to investigate the protective effect of Sal on ethanol-induced acute gastric ulcer and H2O2-induced gastric epithelial cell damage. 0.2 ml ethanol and 400 μM H2O2 were applied to establish a gastric ulcer model in vivo and in vitro respectively. The production of interleukin (IL)-6, interleukin (IL)-1β and tumor necrosis factor (TNF)-α was analyzed, as well as myeloperoxidase (MPO), malondialdehyde (MDA) and superoxide dismutase (SOD). MTT assay was used to detect cell viability. In addition, MAPK/NF-κB signal pathway-related proteins p-ERK, p-JNK, p-p38, p-IκBα and p-NF-κBp65 were analyzed to determine the underlying protective mechanism. Downstream genes such as cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) and leukotrienes B4 (LTB4) were also measured. Obtained data indicated that Sal inhibited the overproduction of pro-inflammatory cytokines and enhanced antioxidant activity. Collectively, it is assumed that Sal could alleviate ethanol-induced acute gastric ulcer and H2O2-induced gastric epithelial cell damage through the MAPK/NF-κB pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

TWEAK promotes migration and invasion in MEFs through a mechanism dependent on ERKs activation and Fibulin 3 down-regulation.

PubMed

Sequera, Celia; Vázquez-Carballo, Ana; Arechederra, María; Fernández-Veledo, Sonia; Porras, Almudena

2018-02-01

TWEAK regulates multiple physio-pathological processes in fibroblasts such as fibrosis. It also induces migration and invasion in tumors and it can activate p38 MAPK in various cell types. Moreover, p38α MAPK promotes migration and invasion in several cancer cells types and in mouse embryonic fibroblasts (MEFs). However, it remains unknown if TWEAK could promote migration in fibroblasts and whether p38α MAPK might play a role. Our results reveal that TWEAK activates ERKs, Akt, and p38α/β MAPKs and reduces secreted Fibulin 3 in MEFs. TWEAK also increases migration and invasion in wt and p38α deficient MEFs, which indicates that p38α MAPK is not required to mediate these effects. In contrast, ERKs inhibition significantly decreases TWEAK-induced migration and Fibulin 3 knock-down mimics TWEAK effect. These results indicate that both ERKs activation and Fibulin 3 down-regulation would contribute to mediate TWEAK pro-migratory effect. In fact, the additional regulation of ERKs and/or p38β as a consequence of Fibulin 3 decrease might be also involved in the pro-migratory effect of TWEAK in MEFs. In conclusion, our studies uncover novel mechanisms by which TWEAK would favor tissue repair by promoting fibroblasts migration. © 2017 Wiley Periodicals, Inc.

JNK signaling pathway regulates sorbitol-induced Tau proteolysis and apoptosis in SH-SY5Y cells by targeting caspase-3.

PubMed

Olivera Santa-Catalina, Marta; Caballero Bermejo, Montaña; Argent, Ricardo; Alonso, Juan C; Centeno, Francisco; Lorenzo, María J

2017-12-15

Growing evidence suggests that Diabetes Mellitus increases the risk of developing Alzheimer's disease. It is well known that hyperglycemia, a key feature of Diabetes Mellitus, may induce plasma osmolarity disturbances. Both hyperglycemia and hyperosmolarity promote the altered post-translational regulation of microtubule-associated protein Tau. Interestingly, abnormal hyperphosphorylation and cleavage of Tau have been proven to lead to the genesis of filamentous structures referred to as neurofibrillary tangles, the main pathological hallmark of Alzheimer's disease. We have previously described that hyperosmotic stress induced by sorbitol promotes Tau proteolysis and apoptosis in SH-SY5Y cells via caspase-3 activation. In order to gain insights into the regulatory mechanisms of such processes, in this work we explored the intracellular signaling pathways that regulate these events. We found that sorbitol treatment significantly enhanced the activation of conventional families of MAPK in SH-SY5Y cells. Tau proteolysis was completely prevented by JNK inhibition but not affected by either ERK1/2 or p38 MAPK blockade. Moreover, inhibition of JNK, but not ERK1/2 or p38 MAPK, efficiently prevented sorbitol-induced apoptosis and caspase-3 activation. In summary, we provide evidence that JNK signaling pathway is an upstream regulator of hyperosmotic stress-induced Tau cleavage and apoptosis in SH-SY5Y through the control of caspase-3 activation. Copyright © 2017 Elsevier Inc. All rights reserved.

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

The Asian-American variant of human papillomavirus type 16 exhibits higher activation of MAPK and PI3K/AKT signaling pathways, transformation, migration and invasion of primary human keratinocytes.

PubMed

Hochmann, Jimena; Sobrinho, João S; Villa, Luisa L; Sichero, Laura

2016-05-01

Asian-American (AA) HPV-16 variants are associated with higher risk of cancer. Abnormal activation of intracellular signaling play a critical role in cancer development and progression. Our aim was to elucidate mechanisms underlying the higher oncogenic potential attributed to AA variant. We evaluated activation of MAPK and PI3K/AKT pathways in primary human keratinocytes (PHKs) transduced with E6/E7 of three HPV-16 variants: E-P, AA, E-350G. Phenotypes examined included migration, anchorage independent growth and invasion. AA PHKs presented the highest levels of active proteins involved in all cascades analyzed: MAPK-ERK, MAPK-p38 and PI3K-AKT. AA PHKs were more efficient in promoting anchorage independent growth, and in stimulating cell migration and invasion. MEK1 inhibition decreased migration. The mesenchymal phenotype marker vimentin was increased in AA PHKs. Our results suggest that MEK1, ERK2, AKT2 hyperactivation influence cellular behavior by means of GSK-3b inactivation and EMT induction prompting AA immortalized PHKs to more efficiently surpass carcinogenesis steps. Copyright © 2016 Elsevier Inc. All rights reserved.

Ampelopsin-induced reactive oxygen species enhance the apoptosis of colon cancer cells by activating endoplasmic reticulum stress-mediated AMPK/MAPK/XAF1 signaling

PubMed Central

Park, Ga Bin; Jeong, Jee-Yeong; Kim, Daejin

2017-01-01

Ampelopsin (Amp) is bioactive natural product and exerts anti-cancer effects against several cancer types. The present study investigated the anti-colon cancer activity of Amp and explored its mechanism of action. The treatment of colon cancer cells with Amp resulted in the dose- and time-dependent induction of apoptosis via the activation of endoplasmic reticulum (ER) stress, 5′ adenosine monophosphate-activated protein kinase (AMPK), and c-Jun N-terminal protein kinase (JNK)/p38 mitogen-activated protein kinases (MAPKs). Salubrinal, an ER stress inhibitor, prevented the upregulation of ER stress-associated proteins, including phosphorylated protein kinase RNA-like ER kinase, phosphorylated eukaryotic translation initiation factor 2α, glucose-regulated protein 78, and CCAAT/enhancer-binding protein homologous protein, as well as suppressing AMPK activation and the MAPK signaling pathway. Knockdown of AMPK by RNA interference failed to block ER stress. Additionally, SP600125 (a JNK inhibitor) and SB203580 (a p38-MAPK inhibitor) effectively inhibited apoptosis and attenuated the expression of X-linked IAP-associated factor 1 (XAF1) and apoptotic Bcl-2 family proteins (BCL2 antagonist/killer 1 and BCL2-associated X protein) in Amp-treated colon cancer cells. Furthermore, reactive oxygen species (ROS)-mediated ER stress/AMPK apoptotic signaling pathway in Amp-treated colon cancer cells were markedly inhibited by treatment with N-acetyl-L-cysteine, a ROS scavenger. These results demonstrate that treatment with Amp induces the apoptotic death of colon cancer cells through ER stress-initiated AMPK/MAPK/XAF1 signaling. These results also provide experimental information for developing Amp as therapeutic drug against colon cancer. PMID:29250183

Luteolin and Apigenin Attenuate 4-Hydroxy-2-Nonenal-Mediated Cell Death through Modulation of UPR, Nrf2-ARE and MAPK Pathways in PC12 Cells

PubMed Central

Wu, Pei-Shan; Yen, Jui-Hung; Kou, Mei-Chun; Wu, Ming-Jiuan

2015-01-01

Luteolin and apigenin are dietary flavones and exhibit a broad spectrum of biological activities including antioxidant, anti-inflammatory, anti-cancer and neuroprotective effects. The lipid peroxidation product 4-hydroxy-2-nonenal (4-HNE) has been implicated as a causative agent in the development of neurodegenerative disorders. This study investigates the cytoprotective effects of luteolin and apigenin against 4-HNE-mediated cytotoxicity in neuronal-like catecholaminergic PC12 cells. Both flavones restored cell viability and repressed caspase-3 and PARP-1 activation in 4-HNE-treated cells. Luteolin also mitigated 4-HNE-mediated LC3 conversion and reactive oxygen species (ROS) production. Luteolin and apigenin up-regulated 4-HNE-mediated unfolded protein response (UPR), leading to an increase in endoplasmic reticulum chaperone GRP78 and decrease in the expression of UPR-targeted pro-apoptotic genes. They also induced the expression of Nrf2-targeted HO-1 and xCT in the absence of 4-HNE, but counteracted their expression in the presence of 4-HNE. Moreover, we found that JNK and p38 MAPK inhibitors significantly antagonized the increase in cell viability induced by luteolin and apigenin. Consistently, enhanced phosphorylation of JNK and p38 MAPK was observed in luteolin- and apigenin-treated cells. In conclusion, this result shows that luteolin and apigenin activate MAPK and Nrf2 signaling, which elicit adaptive cellular stress response pathways, restore 4-HNE-induced ER homeostasis and inhibit cytotoxicity. Luteolin exerts a stronger cytoprotective effect than apigenin possibly due to its higher MAPK, Nrf2 and UPR activation, and ROS scavenging activity. PMID:26087007

INTERPLAY OF SORBITOL PATHWAY OF GLUCOSE METABOLISM, 12/15-LIPOXYGENASE, AND MITOGEN-ACTIVATED PROTEIN KINASES IN THE PATHOGENESIS OF DIABETIC PERIPHERAL NEUROPATHY

PubMed Central

Stavniichuk, Roman; Shevalye, Hanna; Hirooka, Hiroko; Nadler, Jerry L.; Obrosova, Irina G.

2012-01-01

The interactions among multiple pathogenetic mechanisms of diabetic peripheral neuropathy largely remain unexplored. Increased activity of aldose reductase, the first enzyme of the sorbitol pathway, leads to accumulation of cytosolic Ca++, essentially required for 12/15-lipoxygenase activation. The latter, in turn, causes oxidative-nitrosative stress, an important trigger of MAPK phosphorylation. This study therefore evaluated the interplay of aldose reductase, 12/15-lipoxygenase, and MAPKs in diabetic peripheral neuropathy. In experiment 1, male control and streptozotocin-diabetic mice were maintained with or without the aldose reductase inhibitor fidarestat, 16 mg kg−1 d−1, for 12 weeks. In experiment 2, male control and streptozotocin-diabetic wild-type (C57Bl6/J) and 12/15-lipoxygenase-deficient mice were used. Fidarestat treatment did not affect diabetes-induced increase in glucose concentrations, but normalized sorbitol and fructose concentrations (enzymatic spectrofluorometric assays) as well as 12(S) hydroxyeicosatetraenoic concentration (ELISA), a measure of 12/15-lipoxygenase activity, in the sciatic nerve and spinal cord. 12/15-lipoxygenase expression in these two tissues (Western blot analysis) as well as dorsal root ganglia (immunohistochemistry) was similarly elevated in untreated and fidarestat-treated diabetic mice. 12/15-lipoxygenase gene deficiency prevented diabetesassociated p38 MAPK and ERK, but not SAPK/JNK, activation in the sciatic nerve (Western blot analysis) and all three MAPK activation in the dorsal root ganglia (immunohistochemistry). In contrast, spinal cord p38 MAPK, ERK, and SAPK/JNK were similarly activated in diabetic wild-type and 12/15-lipoxygenase−/− mice. These findings identify the nature and tissue specificity of interactions among three major mechanisms of diabetic peripheral neuropathy, and suggest that combination treatments, rather than monotherapies, can sometimes be an optimal choice for its management. PMID:22285226

Regulation of Endothelial Permeability by Glutathione S-Transferase Pi Against Actin Polymerization.

PubMed

Yang, Yang; Yin, Fangyuan; Hang, Qiyun; Dong, Xiaoliang; Chen, Jiao; Li, Ling; Cao, Peng; Yin, Zhimin; Luo, Lan

2018-01-01

Inflammation-induced injury of the endothelial barrier occurs in several pathological conditions, including atherosclerosis, ischemia, and sepsis. Endothelial cytoskeleton rearrangement is an important pathological mechanism by which inflammatory stimulation triggers an increase of vascular endothelial permeability. However, the mechanism maintaining endothelial cell barrier function against inflammatory stress is not fully understood. Glutathione S-transferase pi (GSTpi) exists in various types of cells and protects them against different stresses. In our previous study, GSTpi was found to act as a negative regulator of inflammatory responses. We used a Transwell permeability assay to test the influence of GSTpi and its transferase activity on the increase of endothelial permeability induced by tumor necrosis factor alpha (TNF-α). TNF-α-induced actin remodeling and the influence of GSTpi were observed by using laser confocal microscopy. Western blotting was used to test the influence of GSTpi on TNF-α-activated p38 mitogen-activated protein kinase (MAPK)/MK2/heat shock protein 27 (HSP27). GSTpi reduced TNF-α-induced stress fiber formation and endothelial permeability increase by restraining actin cytoskeleton rearrangement, and this reduction was unrelated to its transferase activity. We found that GSTpi inhibited p38MAPK phosphorylation by directly binding p38 and influenced downstream substrate HSP27-induced actin remodeling. GSTpi inhibited TNF-α-induced actin remodeling, stress fiber formation and endothelial permeability increase by inhibiting the p38MAPK/HSP27 signaling pathway. © 2018 The Author(s). Published by S. Karger AG, Basel.

Aqueous fraction from Cuscuta japonica seed suppresses melanin synthesis through inhibition of the p38 mitogen-activated protein kinase signaling pathway in B16F10 cells.

PubMed

Jang, Ji Yeon; Kim, Ha Neui; Kim, Yu Ri; Choi, Yung Hyun; Kim, Byung Woo; Shin, Hwa Kyoung; Choi, Byung Tae

2012-05-07

Semen cuscutae has been used traditionally to treat pimples and alleviate freckles and melasma in Korea. The present study aimed to investigate the inhibitory effect of Cuscuta japonica Choisy seeds on alpha-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis. The aqueous fraction from Semen cuscutae (AFSC) was used to determine anti-melanogenic effects by examination of cellular melanin contents, tyrosinase activity assay, cAMP assay and Western blot analysis for melanin synthesis-related signaling proteins in B16F10 mouse melanoma cells. AFSC markedly inhibited α-MSH-induced melanin synthesis and tyrosinase activity, and also decreased α-MSH-induced expression of microphthalmia-associated transcription factor (MITF) and tyrosinase-related proteins (TRPs). Moreover, AFSC significantly decreased the level of phosphorylated p38 mitogen-activated protein kinase (MAPK) signaling through the down-regulation of α-MSH-induced cAMP. Furthermore, we confirmed that the specific inhibitor of p38 MAPK (SB203580)-mediated suppressed melanin synthesis and tyrosinase activity was further attenuated by AFSC. AFSC also further decreased SB203580-mediated suppression of MITF and TRP expression. These results indicate that AFSC inhibits p38 MAPK phosphorylation with suppressed cAMP levels and subsequently down-regulate MITF and TRP expression, which results in a marked reduction of melanin synthesis and tyrosinase activity in α-MSH-stimulated B16F10 cells. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Toll-like receptor 4 mediates lipopolysaccharide-induced muscle catabolism via coordinate activation of ubiquitin-proteasome and autophagy-lysosome pathways

PubMed Central

Doyle, Alexander; Zhang, Guohua; Abdel Fattah, Elmoataz A.; Eissa, N. Tony; Li, Yi-Ping

2011-01-01

Cachectic muscle wasting is a frequent complication of many inflammatory conditions, due primarily to excessive muscle catabolism. However, the pathogenesis and intervention strategies against it remain to be established. Here, we tested the hypothesis that Toll-like receptor 4 (TLR4) is a master regulator of inflammatory muscle catabolism. We demonstrate that TLR4 activation by lipopolysaccharide (LPS) induces C2C12 myotube atrophy via up-regulating autophagosome formation and the expression of ubiquitin ligase atrogin-1/MAFbx and MuRF1. TLR4-mediated activation of p38 MAPK is necessary and sufficient for the up-regulation of atrogin1/MAFbx and autophagosomes, resulting in myotube atrophy. Similarly, LPS up-regulates muscle autophagosome formation and ubiquitin ligase expression in mice. Importantly, autophagy inhibitor 3-methyladenine completely abolishes LPS-induced muscle proteolysis, while proteasome inhibitor lactacystin partially blocks it. Furthermore, TLR4 knockout or p38 MAPK inhibition abolishes LPS-induced muscle proteolysis. Thus, TLR4 mediates LPS-induced muscle catabolism via coordinate activation of the ubiquitin-proteasome and the autophagy-lysosomal pathways.—Doyle, A., Zhang, G., Abdel Fattah, E. A., Eissa, N. T., Li, Y.-P. Toll-like receptor 4 mediates lipopolysaccharide-induced muscle catabolism via coordinate activation of ubiquitin-proteasome and autophagy-lysosome pathways. PMID:20826541

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

PubMed

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

2011-01-01

Head kidney leukocytes isolated from Atlantic salmon fed either a diet based on fish oil (FO) or soy bean oil (VO) were used in order to evaluate if different lipid sources could contribute to cellular activation of the salmon innate immune system. A specific inhibitor of p38 MAPK, SB202190, was used to investigate the effect of lipopolysaccharide (LPS) signalling in the head kidney leukocytes. The results show that LPS up regulate IL-1β, TNF-α, Cox2 expression in leukocytes isolated from fish fed either diet. The p38 MAPK inhibitor, SB202190, reduced the LPS induced expression of these genes in both dietary groups. In LPS stimulated leukocytes isolated from VO fed fish, SB202190 showed a clear dose dependent inhibitory effect on IL-1β, TNF-α and Cox2 expression. This effect was also observed for Cox2 in leukocytes isolated from FO fed fish. Furthermore, there was a stronger mean induction of Cox2 in LPS stimulated leucocytes isolated from the VO-group compared to LPS stimulated leukocytes isolated from the FO-group. In both dietary groups, LPS stimulation of salmon head kidney leukocytes increased the induction of CD83, a dendrite cell marker, while the inhibitor reduced CD83 expression in the VO fed fish only. The inhibitor also clearly reduced hsp27 expression in VO fed fish. Indicating a p38 MAPK feedback loop, LPS significantly inhibited the expression of p38MAPK itself in both diets, while SB202190 increased p38MAPK expression especially in the VO diet group. hsp70 expression was not affected by any treatment or feed composition. There were also differences in p38MAPK protein phosphorylation comparing treatment groups but no obvious difference comparing the two dietary groups. The results indicate that dietary fatty acids have the ability to modify signalling through p38 MAPK which may have consequences for the fish's ability to handle infections and stress. Signalling through p38MAPK is ligand dependent and affects gene and protein expression differently. Copyright © 2010 Elsevier Ltd. All rights reserved.

Mini Bypass and Proinflammatory Leukocyte Activation: A Randomized Controlled Trial.

PubMed

Nguyen, Bao A V; Fiorentino, Francesca; Reeves, Barnaby C; Baig, Kamran; Athanasiou, Thanos; Anderson, Jon R; Haskard, Dorian O; Angelini, Gianni D; Evans, Paul C

2016-04-01

Coronary artery bypass grafting (CABG) with conventional cardiopulmonary bypass (CPB) induces systemic inflammation. Miniaturized CPB may attenuate systemic inflammatory activation. The intracellular signaling pathways promoting inflammation in cardiac operations and the relative effects of CPB on these processes are uncertain. In this study, induction of reactive oxygen species (ROS) and activation of nuclear factor (NF)-κB, p38 mitogen-activated protein kinase (MAPK) within leukocytes, and leukocyte accumulation in cantharidin-induced blisters was compared in patients exposed to miniaturized CPB (mCPB) and those who underwent conventional CPB (cCPB). Patients undergoing CABG were randomized to receive either cCPB (n = 13) or mCPB (n = 13). Blood samples were collected preoperatively and 5 times after initiating CPB (up to 5 hours) and analyzed by flow cytometry for intracellular markers of activation (ROS, p38-MAPK, and NF-κB phosphorylation). ROS in lymphocytes were elevated in cCPB compared with mCPB (p < 0.01), whereas ROS in granulocytes and monocytes were similar between groups. After initiation of CPB, p38-MAPK was higher in patients receiving cCPB compared with those receiving mCPB (p < 0.05). NF-κB phosphorylation in leukocyte subsets was similar in patients exposed to cCPB and those exposed to mCPB. Leukocyte accumulation in cantharidin-induced blisters, white cell counts, and serum C-reactive protein (CRP) was enhanced in response to cardiac operations, but no differences were observed between mCPB and cCPB groups. Postoperative serum creatinine levels were reduced in the mCPB group compared with the cCPB group (p < 0.05). Both p38-MAPK activation and ROS were attenuated with the use of mCPB compared with cCPB, providing a potential mechanism for reduced inflammation in association with CPB miniaturization. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Burns, inflammation, and intestinal injury: protective effects of an anti-inflammatory resuscitation strategy.

PubMed

Costantini, Todd W; Peterson, Carrie Y; Kroll, Lauren; Loomis, William H; Putnam, James G; Wolf, Paul; Eliceiri, Brian P; Baird, Andrew; Bansal, Vishal; Coimbra, Raul

2009-12-01

Intestinal barrier breakdown after severe burn can lead to intestinal inflammation, which may act as the source of the systemic inflammatory response. In vitro intestinal cell studies have shown that mitogen-activated protein kinase (MAPK) signaling is an important modulator of intestinal inflammation. We have previously observed that pentoxifylline (PTX) attenuates burn-induced intestinal permeability and tight junction breakdown. We hypothesized that PTX would limit intestinal barrier breakdown and attenuate inflammatory signaling via the MAPK pathway. Male balb/c mice underwent 30% total body surface area full-thickness steam burn. Immediately after burn, animals received an intraperitoneal injection of PTX (12.5 mg/kg) in normal saline or normal saline alone. In vivo intestinal permeability to 4 kDa fluorescein isothiocyanate-dextran was measured. Intestinal extracts were obtained to measure interleukin-6 by enzyme-linked immunosorbent assay, and phosphorylated p38 MAPK, p38 MAPK, phosphorylated extracellular signal-related kinase (1/2) (ERK (1/2)), and ERK (1/2) by immunoblotting. Acute lung injury was assessed by histology at 24 hours after burn. Administration of PTX immediately after injury attenuated burn-induced intestinal permeability. PTX also decreased the burn-induced phosphorylation of p38 MAPK and decreased phosphorylation of ERK (1/2) at 2 hours and 24 hours after injury. Animals given PTX had decreased intestinal interleukin-6 levels. A single dose of PTX also decreased histologic lung injury at 24 hours after burn. PTX attenuates burn-induced intestinal permeability and subsequent intestinal inflammation. Use of PTX after burn was also associated with decreased acute lung injury. Because of its compelling anti-inflammatory effects, PTX may be an ideal candidate for use as an immunomodulatory adjunct to resuscitation fluid.

Protein oxidative damage and heme oxygenase in sunlight-exposed human skin: roles of MAPK responses to oxidative stress.

PubMed

Akasaka, Emiko; Takekoshi, Susumu; Horikoshi, Yosuke; Toriumi, Kentarou; Ikoma, Norihiro; Mabuchi, Tomotaka; Tamiya, Shiho; Matsuyama, Takashi; Ozawa, Akira

2010-12-20

Oxidative stress derived from ultraviolet (UV) light in sunlight induces different hazardous effects in the skin, including sunburn, photo-aging and DNA mutagenesis. In this study, the protein-bound lipid peroxidation products 4-hydroxy-2-nonenal (HNE) and the oxidative DNA damage marker 8-hydroxy-2'-deoxyguanosine (8OHdG) were investigated in chronically sun-exposed and sun-protected human skins using immunohistochemistry. The levels of antioxidative enzymes, such as heme oxygenase 1 and 2, Cu/Zn-SOD, Mn-SOD and catalase, were also examined. Oxidative stress is also implicated in the activation of signal transduction pathways, such as mitogen-activated protein kinase (MAPK). Therefore, the expression and distribution of phosphorylated p38 MAPK, phosphorylated Jun N-terminal kinase (JNK) and phosphorylated extracellular signal-regulated kinase (ERK) were observed. Skin specimens were obtained from the surgical margins. Chronically sunlight-exposed skin samples were taken from the ante-auricular (n = 10) and sunlight-protected skin samples were taken from the post-auricular (n = 10). HNE was increased in the chronically sunlight-exposed skin but not in the sunlight-protected skin. The expression of heme oxygenase-2 was markedly increased in the sunlight-exposed skin compared with the sun-protected skin. In contrast, the intensity of immunostaining of Cu/Zn-SOD, Mn-SOD and catalase was not different between the two areas. Phosphorylated p38 MAPK and phosphorylated JNK accumulated in the ante-auricular dermis and epidermis, respectively. These data show that particular anti-oxidative enzymes function as protective factors in chronically sunlight-exposed human skin. Taken together, our results suggest (1) antioxidative effects of heme oxygenase-2 in chronically sunlight-exposed human skin, and that (2) activation of p38 MAPK may be responsible for oxidative stress.

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

PubMed Central

2015-01-01

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

Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Changchien, Jung-Jung; Chen, Ying-Jung; Huang, Chia-Hui

2015-04-01

Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressedmore » c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression.« less

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

PubMed Central

2013-01-01

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

Adverse effects of MWCNTs on life parameters, antioxidant systems, and activation of MAPK signaling pathways in the copepod Paracyclopina nana.

PubMed

Kim, Duck-Hyun; Puthumana, Jayesh; Kang, Hye-Min; Lee, Min-Chul; Jeong, Chang-Bum; Han, Jeonghoon; Hwang, Dae-Sik; Kim, Il-Chan; Lee, Jin Wuk; Lee, Jae-Seong

2016-10-01

Engineered multi-walled carbon nanotubes (MWCNTs) have received widespread applications in a broad variety of commercial products due to low production cost. Despite their significant commercial applications, CNTs are being discharged to aquatic ecosystem, leading a threat to aquatic life. Thus, we investigated the adverse effect of CNTs on the marine copepod Paracyclopina nana. Additional to the study on the uptake of CNTs and acute toxicity, adverse effects on life parameters (e.g. growth, fecundity, and size) were analyzed in response to various concentrations of CNTs. Also, as a measurement of cellular damage, oxidative stress-related markers were examined in a time-dependent manner. Moreover, activation of redox-sensitive mitogen-activated protein kinase (MAPK) signaling pathways along with the phosphorylation pattern of extracellular signal-regulated kinase (ERK), p38, and c-Jun-N-terminal kinases (JNK) were analyzed to obtain a better understanding of molecular mechanism of oxidative stress-induced toxicity in the copepod P. nana. As a result, significant inhibition on life parameters and evoked antioxidant systems were observed without ROS induction. In addition, CNTs activated MAPK signaling pathway via ERK, suggesting that phosphorylated ERK (p-ERK)-mediated adverse effects are the primary cause of in vitro and in vivo endpoints in response to CNTs exposure. Moreover, ROS-independent activation of MAPK signaling pathway was observed. These findings will provide a better understanding of the mode of action of CNTs on the copepod P. nana at cellular and molecular level and insight on possible ecotoxicological implications in the marine environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Multiple Transduction Pathways Mediate Thyrotropin Receptor Signaling in Preosteoblast-Like Cells

PubMed Central

Boutin, Alisa; Neumann, Susanne

2016-01-01

It has been shown that the TSH receptor (TSHR) couples to a number of different signaling pathways, although the Gs-cAMP pathway has been considered primary. Here, we measured the effects of TSH on bone marker mRNA and protein expression in preosteoblast-like U2OS cells stably expressing TSHRs. We determined which signaling cascades are involved in the regulation of IL-11, osteopontin (OPN), and alkaline phosphatase (ALPL). We demonstrated that TSH-induced up-regulation of IL-11 is primarily mediated via the Gs pathway as IL-11 was up-regulated by forskolin (FSK), an adenylyl cyclase activator, and inhibited by protein kinase A inhibitor H-89 and by silencing of Gαs by small interfering RNA. OPN levels were not affected by FSK, but its up-regulation was inhibited by TSHR/Gi-uncoupling by pertussis toxin. Pertussis toxin decreased p38 MAPK kinase phosphorylation, and a p38 inhibitor and small interfering RNA knockdown of p38α inhibited OPN induction by TSH. Up-regulation of ALPL expression required high doses of TSH (EC50 = 395nM), whereas low doses (EC50 = 19nM) were inhibitory. FSK-stimulated cAMP production decreased basal ALPL expression, whereas protein kinase A inhibition by H-89 and silencing of Gαs increased basal levels of ALPL. Knockdown of Gαq/11 and a protein kinase C inhibitor decreased TSH-stimulated up-regulation of ALPL, whereas a protein kinase C activator increased ALPL levels. A MAPK inhibitor and silencing of ERK1/2 inhibited TSH-stimulated ALPL expression. We conclude that TSH regulates expression of different bone markers via distinct signaling pathways. PMID:26950201

Thioredoxin-mimetic peptide CB3 lowers MAPKinase activity in the Zucker rat brain☆

PubMed Central

Cohen-Kutner, Moshe; Khomsky, Lena; Trus, Michael; Ben-Yehuda, Hila; Lenhard, James M.; Liang, Yin; Martin, Tonya; Atlas, Daphne

2014-01-01

Diabetes is a high risk factor for dementia. High glucose may be a risk factor for dementia even among persons without diabetes, and in transgenic animals it has been shown to cause a potentiation of indices that are pre-symptomatic of Alzheimer's disease. To further elucidate the underlying mechanisms linking inflammatory events elicited in the brain during oxidative stress and diabetes, we monitored the activation of mitogen-activated kinsase (MAPKs), c-jun NH2-terminal kinase (JNK), p38 MAP kinases (p38MAPK), and extracellular activating kinsae1/2 (ERK1/2) and the anti-inflammatory effects of the thioredoxin mimetic (TxM) peptides, Ac-Cys-Pro-Cys-amide (CB3) and Ac-Cys-Gly-Pro-Cys-amide (CB4) in the brain of male leptin-receptor-deficient Zucker diabetic fatty (ZDF) rats and human neuroblastoma SH-SY5Y cells. Daily i.p. injection of CB3 to ZDF rats inhibited the phosphorylation of JNK and p38MAPK, and prevented the expression of thioredoxin-interacting-protein (TXNIP/TBP-2) in ZDF rat brain. Although plasma glucose/insulin remained high, CB3 also increased the phosphorylation of AMP-ribose activating kinase (AMPK) and inhibited p70S6K kinase in the brain. Both CB3 and CB4 reversed apoptosis induced by inhibiting thioredoxin reductase as monitored by decreasing caspase 3 cleavage and PARP dissociation in SH-SY5Y cells. The decrease in JNK and p38MAPK activity in the absence of a change in plasma glucose implies a decrease in oxidative or neuroinflammatory stress in the ZDF rat brain. CB3 not only attenuated MAPK phosphorylation and activated AMPK in the brain, but it also diminished apoptotic markers, most likely acting via the MAPK–AMPK–mTOR pathway. These results were correlated with CB3 and CB4 inhibiting inflammation progression and protection from oxidative stress induced apoptosis in human neuronal cells. We suggest that by attenuating neuro-inflammatory processes in the brain Trx1 mimetic peptides could become beneficial for preventing neurological disorders associated with diabetes. PMID:24624334

Oxymatrine lightened the inflammatory response of LPS-induced mastitis in mice through affecting NF-κB and MAPKs signaling pathways.

PubMed

Yang, Zhengtao; Yin, Ronglan; Cong, Yunfeng; Yang, Zhanqing; Zhou, Ershun; Wei, Zhengkai; Liu, Zhicheng; Cao, Yongguo; Zhang, Naisheng

2014-12-01

Mastitis, an inflammatory reaction of the mammary gland, is recognized as one of the most costly diseases in dairy cattle. Oxymatrine, one of the alkaloids extracted from Chinese herb Sophora flavescens Ait, has been reported to have many biological activities, such as anti-inflammatory, anti-virus, and anti-hepatic fibrosis properties. The aim of this study was to investigate the protective effect and the anti-inflammatory mechanism of oxymatrine on lipopolysaccharide (LPS)-induced mastitis in mice. The mouse mastitis was induced by 10 μg of LPS for 24 h. Oxymatrine was intraperitoneally administered with the dose of 30, 60, and 120 mg/kg 1 h before and 12 h after LPS induction. The results showed that oxymatrine significantly attenuated the damage of the mammary gland induced by LPS. Oxymatrine inhibited the phosphorylation of NF-κB p65 and IκB in NF-κB signal pathway and reduced the phosphorylation of p38, ERK, and JNK in mitogen-activated protein kinase (MAPKs) signal pathway. The results showed that oxymatrine had a protective effect on LPS-induced mastitis, and the anti-inflammatory mechanism of oxymatrine was related to the inhibition of NF-κB and MAPKs signal pathways.

Anti-inflammatory Mechanism of Geniposide: Inhibiting the Hyperpermeability of Fibroblast-Like Synoviocytes via the RhoA/p38MAPK/NF-κB/F-Actin Signal Pathway

PubMed Central

Deng, Ran; Li, Feng; Wu, Hong; Wang, Wen-yu; Dai, Li; Zhang, Zheng-rong; Fu, Jun

2018-01-01

Geniposide (GE) is the extraction and purification of iridoid glycosides from the Gardenia jasminoides Ellis, which is a promising anti-inflammatory drug, but its mechanism of actions on rheumatoid arthritis (RA) has not been clarified. This study investigated the molecular mechanism behind GE reduced the high permeability of fibroblast-like synoviocytes (FLSs) derived from SD rats with adjuvant arthritis (AA), with the aims of observing the action of GE in AA rats and exploring new therapeutic strategies for RA treatment. The CCK-8 method was used to detect FLSs proliferation. The pro-inflammatory cytokines levels and anti-inflammatory cytokines levels in FLSs were determined by ELISA kits. FLSs permeability assay was performed on Transwell. Immunofluorescence was used to assay the arrangement and morphology of F-actin. The expression of the key molecules related to FLSs permeability (RhoA, p-p38MAPK, NF-κB p-p65 and F-actin) was detected by western blotting. After treatment with lipopolysaccharide (LPS), the proliferation and the permeability of the cells increased significantly (all P < 0.05). The expression of RhoA, p-p38MAPK, NF-κB p-p65 and F-actin in FLSs was higher compared with the control group, and F-actin was redistributed, with the formation of additional stress fibers. But, these conditions were moderated after treatment with GE. We demonstrated that the treatment of different concentrations of GE (25, 50, and 100 μg/mL) had a significant inhibitory effect on the proliferation and permeability of FLSs in vitro. Furthermore, the levels of interleukin (IL)-1β and IL-17 secreted by FLSs were decreased in different doses of GE groups, and the levels of anti-inflammatory cytokines (IL-4, TGF-β1) were increased. Under treatment with GE, low expression of RhoA downregulated expression of p-p38MAPK, NF-κB p-p65, and F-actin while compared with control group, and restored the hyperpermeability of FLSs due to LPS treatment. Taken together, GE might play its anti-inflammatory and immunoregulatory effects via regulating the relative equilibrium of pro-inflammatory cytokines and anti-inflammatory cytokines. GE attenuated the hyperpermeability of FLSs. The down-regulation of the conduction of RhoA/p38MAPK/NF-κB/F-actin signal may play a critical role in the mechanisms of GE on RA. GE could be an effective therapeutic agent for the treatment of RA. PMID:29497378

Flavonoid Naringenin: A Potential Immunomodulator for Chlamydia trachomatis Inflammation

PubMed Central

Yilma, Abebayehu N.; Singh, Shree R.; Morici, Lisa; Dennis, Vida A.

2013-01-01

Chlamydia trachomatis, the agent of bacterial sexually transmitted infections, can manifest itself as either acute cervicitis, pelvic inflammatory disease, or a chronic asymptomatic infection. Inflammation induced by C. trachomatis contributes greatly to the pathogenesis of disease. Here we evaluated the anti-inflammatory capacity of naringenin, a polyphenolic compound, to modulate inflammatory mediators produced by mouse J774 macrophages infected with live C. trachomatis. Infected macrophages produced a broad spectrum of inflammatory cytokines (GM-CSF, TNF, IL-1β, IL-1α, IL-6, IL-12p70, and IL-10) and chemokines (CCL4, CCL5, CXCL1, CXCL5, and CXCL10) which were downregulated by naringenin in a dose-dependent manner. Enhanced protein and mRNA gene transcript expressions of TLR2 and TLR4 in addition to the CD86 costimulatory molecule on infected macrophages were modulated by naringenin. Pathway-specific inhibition studies disclosed that p38 mitogen-activated-protein kinase (MAPK) is involved in the production of inflammatory mediators by infected macrophages. Notably, naringenin inhibited the ability of C. trachomatis to phosphorylate p38 in macrophages, suggesting a potential mechanism of its attenuation of concomitantly produced inflammatory mediators. Our data demonstrates that naringenin is an immunomodulator of inflammation triggered by C. trachomatis, which possibly may be mediated upstream by modulation of TLR2, TLR4, and CD86 receptors on infected macrophages and downstream via the p38 MAPK pathway. PMID:23766556

Molecular action mechanism against apoptosis by aqueous extract from guava budding leaves elucidated with human umbilical vein endothelial cell (HUVEC) model.

PubMed

Hsieh, Chiu-Lan; Huang, Chien-Ning; Lin, Yuh-Charn; Peng, Robert Y

2007-10-17

Chronic cardiovascular and neurodegenerative complications induced by hyperglycemia have been considered to be associated most relevantly with endothelial cell damages (ECD). The protective effects of the aqueous extract of Psidium guajava L. budding leaves (PE) on the ECD in human umbilical vein endothelial cell (HUVEC) model were investigated. Results revealed that glyoxal (GO) and methylglyoxal (MGO) resulting from the glycative and autoxidative reactions of the high blood sugar glucose (G) evoked a huge production of ROS and NO, which in turn increased the production of peroxynitrite, combined with the activation of the nuclear factor kappaB (NFkappaB), leading to cell apoptosis. High plasma glucose activated p38-MAPK, and high GO increased the expressions of p38-MAPK and JNK-MAPK, whereas high MGO levels induced the activity of ERK-MAPK. Glucose and dicarbonyl compounds were all found to be good inducers of intracellular PKCs, which together with MAPK acted as the upstream triggering factor to activate NFkappaB. Conclusively, high plasma glucose together with dicarbonyl compounds can trigger the signaling pathways of MAPK and PKC and induce cell apoptosis through ROS and peroxynitrite stimulation and finally by NFkappaB activation. Such effects of PE were ascribed to its high plant polyphenolic (PPP) contents, the latter being potent ROS inhibitors capable of blocking the glycation of proteins, which otherwise could have brought forth severe detrimental effects to the cells.

DIESEL EXHAUST PARTICLES SUPRESS LPS-STIMULATED PRODUCTION OF PGE2 IN HUMAN ALVEOLAR MACHROPHAGES: ROLE OF P38 MAPK AND ERK PATHWAYS

EPA Science Inventory

Numerous studies have reported association between exposure to ambient levels of particulate matter (PM) and adverse health effects, which include respiratory and cardiovascular effects. Diesel exhaust particles (DEP) compose a significant fraction of PM in some areas. Alveolar m...

Integrative analysis of signaling pathways and diseases associated with the miR-106b/25 cluster and their function study in berberine-induced multiple myeloma cells.

PubMed

Gu, Chunming; Li, Tianfu; Yin, Zhao; Chen, Shengting; Fei, Jia; Shen, Jianping; Zhang, Yuan

2017-05-01

Berberine (BBR), a traditional Chinese herbal medicine compound, has emerged as a novel class of anti-tumor agent. Our previous microRNA (miRNA) microarray demonstrated that miR-106b/25 was significantly down-regulated in BBR-treated multiple myeloma (MM) cells. Here, systematic integration showed that miR-106b/25 cluster is involved in multiple cancer-related signaling pathways and tumorigenesis. MiREnvironment database revealed that multiple environmental factors (drug, ionizing radiation, hypoxia) affected the miR-106b/25 cluster expression. By targeting the seed region in the miRNA, tiny anti-mir106b/25 cluster (t-anti-mir106b/25 cluster) significantly induced suppression in cell viability and colony formation. Western blot validated that t-anti-miR-106b/25 cluster effectively inhibited the expression of P38 MAPK and phospho-P38 MAPK in MM cells. These findings indicated the miR-106b/25 cluster functioned as oncogene and might provide a novel molecular insight into MM.

Synergetic topography and chemistry cues guiding osteogenic differentiation in bone marrow stromal cells through ERK1/2 and p38 MAPK signaling pathway.

PubMed

Zhang, Xinran; Li, Haotian; Lin, Chucheng; Ning, Congqin; Lin, Kaili

2018-01-30

Both the topographic surface and chemical composition modification can enhance rapid osteogenic differentiation and bone formation. Till now, the synergetic effects of topography and chemistry cues guiding biological responses have been rarely reported. Herein, the ordered micro-patterned topography and classically essential trace element of strontium (Sr) ion doping were selected to imitate topography and chemistry cues, respectively. The ordered micro-patterned topography on Sr ion-doped bioceramics was successfully duplicated using the nylon sieve as the template. Biological response results revealed that the micro-patterned topography design or Sr doping could promote cell attachment, ALP activity, and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Most importantly, the samples both with micro-patterned topography and Sr doping showed the highest promotion effects, and could synergistically activate the ERK1/2 and p38 MAPK signaling pathways. The results suggested that the grafts with both specific topography and chemistry cues have synergetic effects on osteogenic activity of BMSCs and provide an effective approach to design functional bone grafts and cell culture substrates.

Quercetin suppresses the chymotrypsin-like activity of proteasome via inhibition of MEK1/ERK1/2 signaling pathway in hepatocellular carcinoma HepG2 cells.

PubMed

Ding, Youming; Chen, Xiaoyan; Wang, Bin; Yu, Bin; Ge, Jianhui; Shi, Xiaokang

2018-05-01

The proteasomal system is a promising target for cancer treatment. Quercetin (Que), a flavonoid compound with antitumor ability, displays the inhibitory effect on proteasome activity. However, the underlying molecular mechanisms are ill defined. The present study found that Que treatment significantly reduced the chymotrypsin-like protease activity of proteasome whereas the trypsin- and caspase-like protease activities remained unchanged in HepG2 cancer cells, along with activation of p38 MAPK and JNK and reduction of ERK1/2 phosphorylation. Que-reduced proteasome activity could not be reverted by inhibition of p38 MAPK and JNK signaling pathway. In addition, MEK1 overexpression or knockdown upregulated or downregulated the chymotrypsin-like protease activity of proteasome, respectively. Both Que and MEK1/ERK1/2 inhibitor attenuated the expression levels of proteasome β subunits. These results indicate that Que-induced suppression of MEK1/ERK1/2 signaling and subsequent reduction of proteasome β subunits is responsible for its inhibitory impacts on proteasome activity.

Lipoxin A4-Induced Heme Oxygenase-1 Protects Cardiomyocytes against Hypoxia/Reoxygenation Injury via p38 MAPK Activation and Nrf2/ARE Complex

PubMed Central

Chen, Xiao-Qing; Wu, Sheng-Hua; Zhou, Yu; Tang, Yan-Rong

2013-01-01

Objective To investigate whether lipoxin A4 (LXA4) increases expression of heme oxygenase-1(HO-1) in cardiomyocytes, whether LXA4-induced HO-1 protects cardiomyocytes against hypoxia/reoxygenation (H/R) injury, and what are the mechanisms involved in the LXA4-induced HO-1 induction. Methods Rat cardiomyocytes were exposed to H/R injury with or without preincubation with LXA4 or HO-1 inhibitor ZnPP-IX or various signal molecule inhibitors. Expressions of HO-1 protein and mRNA were analyzed by using Western blot and RT-PCR respectively. Activity of nuclear factor E2-related factor 2 (Nrf2) binding to the HO-1 E1 enhancer was assessed by chromatin immunoprecipitation. Nrf2 binding to the HO-1 antioxidant responsive element (ARE) were measured by using electrophoretic mobility shift assay. Results Pretreatment of the cells undergoing H/R lesion with LXA4 significantly reduced the lactate dehydrogenase and creatine kinase productions, increased the cell viability, and increased the expressions of HO-1 protein and mRNA and HO-1 promoter activity. HO-1 inhibition abolished the protective role of LXA4 on the cells undergoing H/R lesion. LXA4 increased p38 mitogen-activated protein kinase (p38 MAPK) activation, nuclear translocation of Nrf2, Nrf2 binding to the HO-1 ARE and E1 enhancer in cardiomyocytes with or without H/R exposure. Conclusion The protection role of LXA4 against H/R injury of cardiomyocytes is related to upregulation of HO-1, via activation of p38 MAPK pathway and nuclear translocation of Nrf2 and Nrf2 binding to the HO-1 ARE and E1 enhancer, but not via activation of phosphatidyinositol-3-kinase or extracellular signal-regulated kinase pathway. PMID:23826208

Redox-Sensitive Induction of Src/PI3-kinase/Akt and MAPKs Pathways Activate eNOS in Response to EPA:DHA 6:1

PubMed Central

Zgheel, Faraj; Alhosin, Mahmoud; Rashid, Sherzad; Burban, Mélanie; Auger, Cyril; Schini-Kerth, Valérie B.

2014-01-01

Aims Omega-3 fatty acid products containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have vasoprotective effects, in part, by stimulating the endothelial formation of nitric oxide (NO). This study determined the role of the EPA:DHA ratio and amount, and characterized the mechanism leading to endothelial NO synthase (eNOS) activation. Methods and Results EPA:DHA 6∶1 and 9∶1 caused significantly greater endothelium-dependent relaxations in porcine coronary artery rings than EPA:DHA 3∶1, 1∶1, 1∶3, 1∶6, 1∶9, EPA and DHA alone, and EPA:DHA 6∶1 with a reduced EPA + DHA amount, which were inhibited by an eNOS inhibitor. Relaxations to EPA:DHA 6∶1 were insensitive to cyclooxygenase inhibition, and reduced by inhibitors of either oxidative stress, Src kinase, PI3-kinase, p38 MAPK, MEK, or JNK. EPA:DHA 6∶1 induced phosphorylation of Src, Akt, p38 MAPK, ERK, JNK and eNOS; these effects were inhibited by MnTMPyP. EPA:DHA 6∶1 induced the endothelial formation of ROS in coronary artery sections as assessed by dihydroethidium, and of superoxide anions and hydrogen peroxide in cultured endothelial cells as assessed by electron spin resonance with the spin probe CMH, and the Amplex Red based assay, respectively. Conclusion Omega-3 fatty acids cause endothelium-dependent NO-mediated relaxations in coronary artery rings, which are dependent on the EPA:DHA ratio and amount, and involve an intracellular activation of the redox-sensitive PI3-kinase/Akt and MAPKs pathways to activate eNOS. PMID:25133540

Redox-sensitive induction of Src/PI3-kinase/Akt and MAPKs pathways activate eNOS in response to EPA:DHA 6:1.

PubMed

Zgheel, Faraj; Alhosin, Mahmoud; Rashid, Sherzad; Burban, Mélanie; Auger, Cyril; Schini-Kerth, Valérie B

2014-01-01

Omega-3 fatty acid products containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have vasoprotective effects, in part, by stimulating the endothelial formation of nitric oxide (NO). This study determined the role of the EPA:DHA ratio and amount, and characterized the mechanism leading to endothelial NO synthase (eNOS) activation. EPA:DHA 6∶1 and 9∶1 caused significantly greater endothelium-dependent relaxations in porcine coronary artery rings than EPA:DHA 3∶1, 1∶1, 1∶3, 1∶6, 1∶9, EPA and DHA alone, and EPA:DHA 6∶1 with a reduced EPA + DHA amount, which were inhibited by an eNOS inhibitor. Relaxations to EPA:DHA 6∶1 were insensitive to cyclooxygenase inhibition, and reduced by inhibitors of either oxidative stress, Src kinase, PI3-kinase, p38 MAPK, MEK, or JNK. EPA:DHA 6∶1 induced phosphorylation of Src, Akt, p38 MAPK, ERK, JNK and eNOS; these effects were inhibited by MnTMPyP. EPA:DHA 6∶1 induced the endothelial formation of ROS in coronary artery sections as assessed by dihydroethidium, and of superoxide anions and hydrogen peroxide in cultured endothelial cells as assessed by electron spin resonance with the spin probe CMH, and the Amplex Red based assay, respectively. Omega-3 fatty acids cause endothelium-dependent NO-mediated relaxations in coronary artery rings, which are dependent on the EPA:DHA ratio and amount, and involve an intracellular activation of the redox-sensitive PI3-kinase/Akt and MAPKs pathways to activate eNOS.

Mitogen-activated protein kinases (MAPKs) regulate IL-6 over-production during concomitant influenza virus and Staphylococcus aureus infection.

PubMed

Klemm, Carolin; Bruchhagen, Christin; van Krüchten, Andre; Niemann, Silke; Löffler, Bettina; Peters, Georg; Ludwig, Stephan; Ehrhardt, Christina

2017-02-14

Bacterial super-infections are a major complication of influenza virus (IV) infections and often lead to severe pneumonia. One hallmark of IV-associated Staphylococcus aureus (S. aureus) infection is rapid progression to a serious disease outcome. Changes in immune and inflammatory host responses increase morbidity and complicate efficient therapy. A key player during inflammation is the multifunctional cytokine IL-6. Although increased IL-6 levels have been observed after severe disease upon IV and/or bacterial super-infection, the underlying molecular mechanisms still remain to be elucidated. In the present study, we focused on cellular signalling pathways regulating IL-6 production upon IV/S. aureus super-infection. Additionally, infection with viable bacteria was mimicked by lipoteichoic acid stimulation in this model. Analyses of cellular signalling mechanisms revealed synergistically increased activation of the MAPK p38 as well as enhanced phosphorylation of the MAPKs ERK1/2 and JNK in the presence of super-infecting bacteria. Interestingly, inhibition of MAPK activity indicated a strong dependence of IL-6 expression on p38 and ERK1/2, while the MAPK JNK seems not to be involved. Thus, our results provide new molecular insights into the regulation of IL-6, a marker of severe disease, which might contribute to the lethal synergism of IV and S. aureus.

The Nuclear Dbf2-Related Kinase COT1 and the Mitogen-Activated Protein Kinases MAK1 and MAK2 Genetically Interact to Regulate Filamentous Growth, Hyphal Fusion and Sexual Development in Neurospora crassa

PubMed Central

Maerz, Sabine; Ziv, Carmit; Vogt, Nico; Helmstaedt, Kerstin; Cohen, Nourit; Gorovits, Rena; Yarden, Oded; Seiler, Stephan

2008-01-01

Ndr kinases, such as Neurospora crassa COT1, are important for cell differentiation and polar morphogenesis, yet their input signals as well as their integration into a cellular signaling context are still elusive. Here, we identify the cot-1 suppressor gul-4 as mak-2 and show that mutants of the gul-4/mak-2 mitogen-activated protein (MAP) kinase pathway suppress cot-1 phenotypes along with a concomitant reduction in protein kinase A (PKA) activity. Furthermore, mak-2 pathway defects are partially overcome in a cot-1 background and are associated with increased MAK1 MAPK signaling. A comparative characterization of N. crassa MAPKs revealed that they act as three distinct modules during vegetative growth and asexual development. In addition, common functions of MAK1 and MAK2 signaling during maintenance of cell-wall integrity distinguished the two ERK-type pathways from the p38-type OS2 osmosensing pathway. In contrast to separate functions during vegetative growth, the concerted activity of the three MAPK pathways is essential for cell fusion and for the subsequent formation of multicellular structures that are required for sexual development. Taken together, our data indicate a functional link between COT1 and MAPK signaling in regulating filamentous growth, hyphal fusion, and sexual development. PMID:18562669

The effect of RO3201195 and a pyrazolyl ketone P38 MAPK inhibitor library on the proliferation of Werner syndrome cells.

PubMed

Bagley, Mark C; Dwyer, Jessica E; Baashen, Mohammed; Dix, Matthew C; Murziani, Paola G S; Rokicki, Michal J; Kipling, David; Davis, Terence

2016-01-21

Microwave-assisted synthesis of the pyrazolyl ketone p38 MAPK inhibitor RO3201195 in 7 steps and 15% overall yield, and the comparison of its effect upon the proliferation of Werner Syndrome cells with a library of pyrazolyl ketones, strengthens the evidence that p38 MAPK inhibition plays a critical role in modulating premature cellular senescence in this progeroid syndrome and the reversal of accelerated ageing observed in vitro on treatment with SB203580.

Hsf1 in Her2-Positive Breast Cancer

DTIC Science & Technology

2012-10-01

to heat shock proteins (Hsps) such as Hsp70, Hsp90, and Hsp27 , though besides Hsps, Hsf1 regulates hundreds of other targets (32). Initially, Hsps...phos- phorylation of p38MAPK and phosphorylation of its substrate Hsp27 (Fig. 2A). Activation of p38MAPK led to the activation of its down- stream...IR as demonstrated by suppression of Hsp27 phosphorylation and IL-6 and IL-8 transcription (Fig. 2A; Fig. S10B). Importantly, inhibition of p38MAPK

Second-generation inhibitors demonstrate the involvement of p38 mitogen-activated protein kinase in post-transcriptional modulation of inflammatory mediator production in human and rodent airways.

PubMed

Birrell, Mark A; Wong, Sissie; McCluskie, Kerryn; Catley, Matthew C; Hardaker, Elizabeth L; Haj-Yahia, Saleem; Belvisi, Maria G

2006-03-01

The exact role of p38 mitogen-activated protein kinase (MAPK) in the expression of inflammatory cytokines is not clear; it may regulate transcriptionally, post-transcriptionally, translationally, or post-translationally. The involvement of one or more of these mechanisms has been suggested to depend on the particular cytokine, the cell type studied, and the specific stimulus used. Interpretation of some of the published data is further complicated by the use of inhibitors such as 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole (SB 203580) used at single, high concentrations. The aim of this study was to determine the impact of two second-generation p38 MAPK inhibitors on the expression of a range of inflammatory cytokines at the gene and protein levels in human cultured cells. Similar assessment of the impact of these compounds on inflammatory cytokine expression in a preclinical in vivo model of airway inflammation was performed. The results in THP-1 cells and primary airway macrophages clearly show that protein expression is inhibited at much lower concentrations of inhibitor than are needed to impact on gene expression. In the rodent model, both compounds, at doses that cause maximal inhibition of cellular recruitment, inhibit tumor necrosis factor alpha (TNFalpha) protein production without impacting on nuclear factor kappaB pathway activation or TNFalpha gene expression. In summary, the data shown here demonstrate that, although at high compound concentrations there is some level of transcriptional regulation, the predominant role of p38 MAPK in cytokine production is at the translational level. These data question whether the effect of p38 inhibitors on gene transcription is related to their potential therapeutic role as anti-inflammatory compounds.

P38 delta MAPK promotes breast cancer progression and lung metastasis by enhancing cell proliferation and cell detachment.

PubMed

Wada, M; Canals, D; Adada, M; Coant, N; Salama, M F; Helke, K L; Arthur, J S; Shroyer, K R; Kitatani, K; Obeid, L M; Hannun, Y A

2017-11-23

The protein p38 mitogen-activated protein kinase (MAPK) delta isoform (p38δ) is a poorly studied member of the MAPK family. Data analysis from The Cancer Genome Atlas database revealed that p38δ is highly expressed in all types of human breast cancers. Using a human breast cancer tissue array, we confirmed elevation in cancer tissue. The breast cancer mouse model, MMTV-PyMT (PyMT), developed breast tumors with lung metastasis; however, mice deleted in p38δ (PyMT/p38δ -/- ) exhibited delayed primary tumor formation and highly reduced lung metastatic burden. At the cellular level, we demonstrate that targeting of p38δ in breast cancer cells, MCF-7 and MDA-MB-231 resulted in a reduced rate of cell proliferation. In addition, cells lacking p38δ also displayed an increased cell-matrix adhesion and reduced cell detachment. This effect on cell adhesion was molecularly supported by the regulation of the focal adhesion kinase by p38δ in the human breast cell lines. These studies define a previously unappreciated role for p38δ in breast cancer development and evolution by regulating tumor growth and altering metastatic properties. This study proposes MAPK p38δ protein as a key factor in breast cancer. Lack of p38δ resulted in reduced primary tumor size and blocked the metastatic potential to the lungs.

Ursolic acid inhibits proliferation and induces apoptosis of HT-29 colon cancer cells by inhibiting the EGFR/MAPK pathway*

PubMed Central

Shan, Jian-zhen; Xuan, Yan-yan; Zheng, Shu; Dong, Qi; Zhang, Su-zhan

2009-01-01

Objective: To investigate the effects of ursolic acid on the proliferation and apoptosis of human HT-29 colon cancer cells. Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays were performed to evaluate the effects of ursolic acid on the growth and apoptosis of HT-29 cells. Western blot analysis was applied to investigate the inhibitory effects of ursolic acid on the phosphorylation of the epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK), and the activity of B cell leukemia-2 (Bcl-2), B cell leukemia-xL (Bcl-xL), caspase-3, and caspase-9. Results: Ursolic acid inhibited the growth of HT-29 cells in dose- and time-dependent manners. The median inhibition concentration (IC50) values for 24, 48, and 72 h treatment were 26, 20, and 18 μmol/L, respectively. The apoptotic rates of 10, 20, and 40 μmol/L ursolic acid treatments for 24 h were 5.74%, 14.49%, and 33.05%, and for 48 h were 9%, 21.39%, and 40.49%, respectively. Ursolic acid suppressed the phosphorylation of EGFR, ERK1/2, p38 MAPK, and JNK, which is well correlated with its growth inhibitory effect. 10, 20, and 40 μmol/L ursolic acid significantly inhibited the proliferation of EGF-stimulated HT-29 cells (P<0.05). Cell proliferation was most significantly inhibited when treated with 10 and 20 μmol/L ursolic acid combined with 200 nmol/L AG 1478 or 10 μmol/L U0126 (P<0.01). Besides, it also down-regulated the expression of Bcl-2 and Bcl-xL and activated caspase-3 and caspase-9. Conclusion: Ursolic acid induces apoptosis in HT-29 cells by suppressing the EGFR/MAPK pathway, suggesting that it may be a potent agent for the treatment of colorectal cancer. PMID:19735099

Excessive L-cysteine induces vacuole-like cell death by activating endoplasmic reticulum stress and mitogen-activated protein kinase signaling in intestinal porcine epithelial cells.

PubMed

Ji, Yun; Wu, Zhenlong; Dai, Zhaolai; Sun, Kaiji; Zhang, Qing; Wu, Guoyao

2016-01-01

High intake of dietary cysteine is extremely toxic to animals and the underlying mechanism remains largely unknown. This study was conducted to test the hypothesis that excessive L-cysteine induces cell death by activating endoplasmic reticulum (ER) stress and mitogen-activated protein kinase (MAPK) signaling in intestinal porcine epithelial cells. Jejunal enterocytes were cultured in the presence of 0-10 mmol/L L-cysteine. Cell viability, morphologic alterations, mRNA levels for genes involved in ER stress, protein abundances for glucose-regulated protein 78, C/EBP homologous protein (CHOP), alpha subunit of eukaryotic initiation factor-2 (eIF2α), extracellular signal-regulated kinase (ERK1/2), p38 MAPK, and c-Jun N-terminal protein kinase (JNK1/2) were determined. The results showed that L-cysteine (5-10 mmol/L) reduced cell viability (P < 0.05) and led to vacuole-like cell death in intestinal porcine epithelial cells. These adverse effects of L-cysteine were not affected by the autophagy inhibitor 3-methyladenine. The protein abundances for CHOP, phosphorylated (p)-eIF2α, p-JNK1/2, p-p38 MAPK, and the spliced form of XBP-1 mRNA were enhanced (P < 0.05), whereas those for p-ERK1/2 were reduced (P < 0.05). Collectively, excessive L-cysteine induces vacuole-like cell death via the activation of ER stress and MAPK signaling in small intestinal epithelial cells. These signaling pathways may be potential targets for developing effective strategies to prevent the toxicity of dietary cysteine.

Paclitaxel suppresses proliferation and induces apoptosis through regulation of ROS and the AKT/MAPK signaling pathway in canine mammary gland tumor cells.

PubMed

Ren, Xiaoli; Zhao, Bingbing; Chang, Hongjian; Xiao, Min; Wu, Yuhong; Liu, Yun

2018-06-01

Paclitaxel is a diterpenoid compound, derived from the pacific yew (Taxus brevifolia) berry, which exhibits antineoplastic effects against various types of cancer. However, the antitumor effects and the molecular mechanisms of paclitaxel on canine CHMm cells remain to be elucidated. The aim of the present study was to investigate the antitumor effects of paclitaxel on CHMm cells and identify relevant signal transduction pathways modulated by paclitaxel using multiple methods including MTT assay, flow cytometry, acridine orange/ethidium bromide staining, transmission electron microscopy, determination of cellular reactive oxygen species (ROS), superoxide dismutase (SOD) and malondiadehyde (MDA) and western blotting, the data indicated that paclitaxel decreased cell viability, induced G2/M‑phase cell cycle arrest, suppressed the expression of cyclin B1 and induced apoptosis in a dose‑dependent manner. In addition, paclitaxel upregulated the expression of Bax and cytochrome c, but reduced expression of apoptosis regulator Bcl‑2, resulting in activation of caspase‑3, chromatin condensation, karyopyknosis, intracellular vacuolization, increased production of ROS and MDA, and decreased activity of SOD. However, these effects were inhibited when CHMm cells were treated with N‑acetyl‑L‑cysteine. Furthermore, treatment with paclitaxel inhibited the level of of phospho (p)‑RAC‑α serine/threonine‑protein kinase (AKT) and p‑ribosomal protein S6 kinase proteins, and promoted phosphorylation of P38 mitogen‑activated protein kinase (MAPK) and p‑90 kDa ribosomal protein S6 kinase 1 proteins in CHMm cells. It was observed that paclitaxel in combination with pharmacological inhibitors of the P38 and phosphatidylinositol‑4,5‑bisphosphate 3‑kinase (PI3K) signaling pathways (SB203580 and LY294002, respectively) exerted synergistic inhibitory effects on the proliferation of the CHMm cells. The results of the present study demonstrated that paclitaxel inhibited tumor cell proliferation by increasing intrinsic apoptosis through inhibition of the PI3K/AKT signaling pathway and activation of MAPK signaling pathway in CHMm cells.

A Role for p38 Mitogen-activated Protein Kinase-mediated Threonine 30-dependent Norepinephrine Transporter Regulation in Cocaine Sensitization and Conditioned Place Preference*

PubMed Central

Mannangatti, Padmanabhan; NarasimhaNaidu, Kamalakkannan; Damaj, Mohamad Imad; Ramamoorthy, Sammanda; Jayanthi, Lankupalle Damodara

2015-01-01

The noradrenergic and p38 mitogen-activated protein kinase (p38 MAPK) systems are implicated in cocaine-elicited behaviors. Previously, we demonstrated a role for p38 MAPK-mediated norepinephrine transporter (NET) Thr30 phosphorylation in cocaine-induced NET up-regulation (Mannangatti, P., Arapulisamy, O., Shippenberg, T. S., Ramamoorthy, S., and Jayanthi, L. D. (2011) J. Biol. Chem. 286, 20239–20250). The present study explored the functional interaction between p38 MAPK-mediated NET regulation and cocaine-induced behaviors. In vitro cocaine treatment of mouse prefrontal cortex synaptosomes resulted in enhanced NET function, surface expression, and phosphorylation. Pretreatment with PD169316, a p38 MAPK inhibitor, completely blocked cocaine-mediated NET up-regulation and phosphorylation. In mice, in vivo administration of p38 MAPK inhibitor SB203580 completely blocked cocaine-induced NET up-regulation and p38 MAPK activation in the prefrontal cortex and nucleus accumbens. When tested for cocaine-induced locomotor sensitization and conditioned place preference (CPP), mice receiving SB203580 on cocaine challenge day or on postconditioning test day exhibited significantly reduced cocaine sensitization and CPP. A transactivator of transcription (TAT) peptide strategy was utilized to test the involvement of the NET-Thr30 motif. In vitro treatment of synaptosomes with TAT-NET-Thr30 (wild-type peptide) completely blocked cocaine-mediated NET up-regulation and phosphorylation. In vivo administration of TAT-NET-Thr30 peptide but not TAT-NET-T30A (mutant peptide) completely blocked cocaine-mediated NET up-regulation and phosphorylation. In the cocaine CPP paradigm, mice receiving TAT-NET-Thr30 but not TAT-NET-T30A on postconditioning test day exhibited significantly reduced cocaine CPP. Following extinction, TAT-NET-Thr30 when given prior to cocaine challenge significantly reduced reinstatement of cocaine CPP. These results demonstrate that the direct inhibition of p38 MAPK or the manipulation of NET-Thr30 motif/phosphorylation via a TAT peptide strategy prevents cocaine-induced NET up-regulation, locomotor sensitization, and CPP, suggesting a role for Thr30-linked NET regulation in cocaine-elicited behaviors. PMID:25724654

KIR2DL4 differentially signals downstream functions in human NK cells through distinct structural modules.

PubMed

Miah, S M Shahjahan; Hughes, Tracey L; Campbell, Kerry S

2008-03-01

KIR2DL4 (2DL4) is a member of the killer cell Ig-like receptor (KIR) family in human NK cells. It can stimulate potent cytokine production and weak cytolytic activity in resting NK cells, but the mechanism for 2DL4-mediated signaling remains unclear. In this study we characterized the signaling pathways stimulated by 2DL4 engagement. In a human NK-like cell line, KHYG-1, cross-linking of 2DL4 activated MAPKs including JNK, ERK, and p38. Furthermore, 2DL4 cross-linking resulted in phosphorylation of IkappaB kinase beta (IKKbeta) and the phosphorylation and degradation of IkappaBalpha, which indicate activation of the classical NF-kappaB pathway. Engagement of 2DL4 was also shown to activate the transcription and translation of a variety of cytokine genes, including TNF-alpha, IFN-gamma, MIP1alpha, MIP1beta, and IL-8. Pharmacological inhibitors of JNK, MEK1/2 and p38, blocked IFN-gamma, IL-8, and MIP1alpha production, suggesting that MAPKs are regulating 2DL4-mediated cytokine production in a nonredundant manner. Activation of both p38 and ERK appear to be upstream of the stimulation of NF-kappaB. Mutation of a transmembrane arginine in 2DL4 to glycine (R/G mutant) abrogated FcepsilonRI-gamma association, as well as receptor-mediated cytolytic activity and calcium responses. Surprisingly, the R/G mutant still activated MAPKs and the NF-kappaB pathway and selectively stimulated the production of MIP1alpha, but not that of IFN-gamma or IL-8. In conclusion, we provide evidence that the activating functions of 2DL4 can be compartmentalized into two distinct structural modules: 1) through transmembrane association with FcepsilonRI-gamma; and 2) through another receptor domain independent of the transmembrane arginine.

The protective effect of lidocaine on lipopolysaccharide-induced acute lung injury in rats through NF-κB and p38 MAPK signaling pathway and excessive inflammatory responses.

PubMed

Chen, L-J; Ding, Y-B; Ma, P-L; Jiang, S-H; Li, K-Z; Li, A-Z; Li, M-C; Shi, C-X; Du, J; Zhou, H-D

2018-04-01

Acute lung injury is a severe disease with a high rate of mortality, leading to more important illness. We aimed at exploring the protective role and potential mechanisms of lidocaine on lipopolysaccharide (LPS)-induced acute lung injury (ALI). Sprague Dawley (SD) rats were randomly assigned to control group receiving 0.9% saline solution, LPS group treated with 4 mg/kg LPS i.p., LPS + lidocaine(treated with 4 mg/kg LPS i.p. followed by giving 1 mg/kg, 3 mg/kg, 5 mg/kg of lidocaine i.v.). Lung specimens and the bronchoalveolar lavage fluid (BALF) were collected for histopathological examination and biochemical analyze 12 h after LPS induction. The cytokines expression of TNF-α, IL-6 and MCP-1 was measured by ELISA. In addition, the malondialdehyde (MDA) content, the activities of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) in lung tissues were also detected using ELISA. The protein expressions of p38, p-p38, p65, p-p65 and IκB were analyzed by Western blot. The results indicated that after lidocaine treatment was able to decrease significantly wet-to-dry (W/D) ratio and ameliorate the histopathologic damage. Additionally, total protein content and the number of leukocytes in BALF significantly decreased. ELISA result indicated that the levels of TNF-α, IL-6 and MCP-1 in BALF were markedly suppressed. Meanwhile, the activities of T-AOC and SOD in lung tissues significantly increased, while the content of MDA significantly decreased after treatment with lidocaine. Moreover, Western blot suggested that lidocaine inhibited phosphorylation of NF-κB p65 and p38 MAPK. Therefore, lidocaine could ameliorate the LPS-induced lung injury via NF-κB/p38 MAPK signaling and excessive inflammatory responses, providing a potential for becoming the anti-inflammatory agent against lung injury.

Cinnamophilin isolated from Cinnamomum philippinense protects against collagen degradation in human chondrocytes.

PubMed

Lu, Yung-Chang; Hsiao, George; Lin, Kuan-Hung; Hsieh, Ming-Shium; Jayakumar, Thanasekaran; Wu, Tian-Shung; Sheu, Joen-Rong

2013-06-01

To investigate the therapeutic potential of naturally occurring cinnamophilin against cartilage degradation and its action mechanisms, its effects on matrix metalloproteinase (MMP)-1 and -13 induction were examined in the human SW1353 chondrocytic cell line. Human chondrocytes (SW1353) were stimulated with interleukin (IL)-1β, and then mitogen-activated protein kinase (MAPK) and c-Jun activations, inhibitory κB-α (IκB-α) degradation, and MMP-1, and 13 expressions were assayed by a Western blot analysis. Cinnamophilin strongly inhibited MMP-1 and -13 induction in IL-1β-treated (30 ng/mL) SW1353 cells in a concentration-dependent manner, and it also reduced MAPK family members including extracellular signal-regulated kinase (ERK), p38 MAPKs, and c-Jun N-terminal kinase. Moreover, nuclear factor (NF)-κB signaling activation through IκB-α degradation, IκB kinase (IKK)-α/β, and p-65 phosphorylation was restored by cinnamophilin upon IL-1β stimulation. Importantly, results showed that IL-1β-induced activation of phosphorylated (p)-c-Jun in chondrocytes was significantly inhibited by cinnamophilin. These results indicate that cinnamophilin inhibited MMP-1 and -13 expressions in IL-1β-treated chondrocytes through either NF-κB or ERK/p38 MAPK downregulation and/or suppressing p-c-Jun pathways. Furthermore, these findings suggest that cinnamophilin may have the potential for chondroprotection against collagen matrix breakdown in cartilage of diseased tissues such as those found in arthritic disorders. Copyright © 2012 John Wiley & Sons, Ltd.

Kinase cascades and ligand-directed signaling at the kappa opioid receptor.

PubMed

Bruchas, Michael R; Chavkin, Charles

2010-06-01

The dynorphin/kappa opioid receptor (KOR) system has been implicated as a critical component of the stress response. Stress-induced activation of dynorphin-KOR is well known to produce analgesia, and more recently, it has been implicated as a mediator of stress-induced responses including anxiety, depression, and reinstatement of drug seeking. Drugs selectively targeting specific KOR signaling pathways may prove potentially useful as therapeutic treatments for mood and addiction disorders. KOR is a member of the seven transmembrane spanning (7TM) G-protein coupled receptor (GPCR) superfamily. KOR activation of pertussis toxin-sensitive G proteins leads to Galphai/o inhibition of adenylyl cyclase production of cAMP and releases Gbetagamma, which modulates the conductances of Ca(+2) and K(+) channels. In addition, KOR agonists activate kinase cascades including G-protein coupled Receptor Kinases (GRK) and members of the mitogen-activated protein kinase (MAPK) family: ERK1/2, p38 and JNK. Recent pharmacological data suggests that GPCRs exist as dynamic, multi-conformational protein complexes that can be directed by specific ligands towards distinct signaling pathways. Ligand-induced conformations of KOR that evoke beta-arrestin-dependent p38 MAPK activation result in aversion; whereas ligand-induced conformations that activate JNK without activating arrestin produce long-lasting inactivation of KOR signaling. In this review, we discuss the current status of KOR signal transduction research and the data that support two novel hypotheses: (1) KOR selective partial agonists that do not efficiently activate p38 MAPK may be useful analgesics without producing the dysphoric or hallucinogenic effects of selective, highly efficacious KOR agonists and (2) KOR antagonists that do not activate JNK may be effective short-acting drugs that may promote stress-resilience.

Involvement of nuclear factor κB in platelet CD40 signaling.

PubMed

Hachem, Ahmed; Yacoub, Daniel; Zaid, Younes; Mourad, Walid; Merhi, Yahye

2012-08-17

CD40 ligand (CD40L) is a thrombo-inflammatory molecule that predicts cardiovascular events. Platelets constitute the major source of soluble CD40L (sCD40L), which has been shown to potentiate platelet activation and aggregation, in a CD40-dependent manner, via p38 mitogen activated protein kinase (MAPK) and Rac1 signaling. In many cells, the CD40L/CD40 dyad also induces activation of nuclear factor kappa B (NF-κB). Given that platelets contain NF-κB, we hypothesized that it may be involved in platelet CD40 signaling and function. In human platelets, sCD40L induces association of CD40 with its adaptor protein the tumor necrosis factor receptor associated factor 2 and triggers phosphorylation of IκBα, which are abolished by CD40L blockade. Inhibition of IκBα phosphorylation reverses sCD40L-induced IκBα phosphorylation without affecting p38 MAPK phosphorylation. On the other hand, inhibition of p38 MAPK phosphorylation has no effect on IκBα phosphorylation, indicating a divergence in the signaling pathway originating from CD40 upon its ligation. In functional studies, inhibition of IκBα phosphorylation reverses sCD40L-induced platelet activation and potentiation of platelet aggregation in response to a sub-threshold concentration of collagen. This study demonstrates that the sCD40L/CD40 axis triggers NF-κB activation in platelets. This signaling pathway plays a critical role in platelet activation and aggregation upon sCD40L stimulation and may represent an important target against thrombo-inflammatory disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

Arctigenin Induces an Activation Response in Porcine Alveolar Macrophage Through TLR6-NOX2-MAPKs Signaling Pathway.

PubMed

Lu, Zheng; Chang, Lingling; Du, Qian; Huang, Yong; Zhang, Xiujuan; Wu, Xingchen; Zhang, Jie; Li, Ruizhen; Zhang, Zelin; Zhang, Wenlong; Zhao, Xiaomin; Tong, Dewen

2018-01-01

Arctigenin (ARG), one of the most active ingredients abstracted from seeds of Arctium lappa L. , has been proved to exert promising biological activities such as immunomodulatory, anti-viral, and anti-cancer etc. However, the mechanism behind its immunomodulatory function still remains elusive to be further investigated. In this study, we found that ARG had no significant effects on the cell proliferation in both porcine alveolar macrophage cell line (3D4/21) and primary porcine derived alveolar macrophage. It remarkably increased the expression and secretion of the two cytokines including tumor necrosis factor-alpha (TNF-α) and transforming growth factor beta1 (TGF-β1) in a dose-dependent manner with the concomitant enhancement of phagocytosis, which are the indicators of macrophage activation. ARG also elevated the intracellular reactive oxygen species (ROS) production by activating NOX2-based NADPH oxidase. Furthermore, inhibition of ROS generation by diphenyliodonium and apocynin significantly suppressed ARG-induced cytokine secretion and phagocytosis increase, indicating the requirement of ROS for the porcine alveolar macrophage activation. In addition, TLR6-My88 excitation, p38 MAPK and ERK1/2 phosphorylation were all involved in the process. As blocking TLR6 receptor dramatically attenuated the NOX2 oxidase activation, cytokine secretion and phagocytosis increase. Inhibiting ROS generation almost abolished p38 and ERK1/2 phosphorylation, and the cytokine secretion could also be remarkably reduced by p38 and ERK1/2 inhibitors (SB203580 and UO126). Our finding gave a new insight of understanding that ARG could improve the immune-function of porcine alveolar macrophages through TLR6-NOX2 oxidase-MAPKs signaling pathway.

Arctigenin Induces an Activation Response in Porcine Alveolar Macrophage Through TLR6-NOX2-MAPKs Signaling Pathway

PubMed Central

Lu, Zheng; Chang, Lingling; Du, Qian; Huang, Yong; Zhang, Xiujuan; Wu, Xingchen; Zhang, Jie; Li, Ruizhen; Zhang, Zelin; Zhang, Wenlong; Zhao, Xiaomin; Tong, Dewen

2018-01-01

Arctigenin (ARG), one of the most active ingredients abstracted from seeds of Arctium lappa L., has been proved to exert promising biological activities such as immunomodulatory, anti-viral, and anti-cancer etc. However, the mechanism behind its immunomodulatory function still remains elusive to be further investigated. In this study, we found that ARG had no significant effects on the cell proliferation in both porcine alveolar macrophage cell line (3D4/21) and primary porcine derived alveolar macrophage. It remarkably increased the expression and secretion of the two cytokines including tumor necrosis factor-alpha (TNF-α) and transforming growth factor beta1 (TGF-β1) in a dose-dependent manner with the concomitant enhancement of phagocytosis, which are the indicators of macrophage activation. ARG also elevated the intracellular reactive oxygen species (ROS) production by activating NOX2-based NADPH oxidase. Furthermore, inhibition of ROS generation by diphenyliodonium and apocynin significantly suppressed ARG-induced cytokine secretion and phagocytosis increase, indicating the requirement of ROS for the porcine alveolar macrophage activation. In addition, TLR6-My88 excitation, p38 MAPK and ERK1/2 phosphorylation were all involved in the process. As blocking TLR6 receptor dramatically attenuated the NOX2 oxidase activation, cytokine secretion and phagocytosis increase. Inhibiting ROS generation almost abolished p38 and ERK1/2 phosphorylation, and the cytokine secretion could also be remarkably reduced by p38 and ERK1/2 inhibitors (SB203580 and UO126). Our finding gave a new insight of understanding that ARG could improve the immune-function of porcine alveolar macrophages through TLR6-NOX2 oxidase-MAPKs signaling pathway. PMID:29867481

Functional and molecular characterization of multiple K-Cl cotransporter isoforms in corneal epithelial cells

PubMed Central

Capó-Aponte, José E.; Wang, Zheng; Bildin, Victor N.; Iserovich, Pavel; Pan, Zan; Zhang, Fan; Pokorny, Kathryn S.; Reinach, Peter S.

2009-01-01

The dependence of regulatory volume decrease (RVD) activity on potassium–chloride cotransporter (KCC) isoform expression was characterized in corneal epithelial cells (CEC). During exposure to a 50% hypotonic challenge, the RVD response was larger in SV40-immortalized human CEC (HCEC) than in SV40-immortalized rabbit CEC (RCEC). A KCC inhibitor—[(dihydroindenyl)oxy] alkanoic acid (DIOA)—blocked RVD more in HCEC than RCEC. Under isotonic conditions, N-ethylmaleimide (NEM) produced KCC activation and transient cell shrinkage. Both of these changes were greater in HCEC than in RCEC. Immunoblot analysis of HCEC, RCEC, primary human CEC (pHCEC), and primary bovine CEC (BCEC) plasma membrane enriched fractions revealed KCC1, KCC3, and KCC4 isoform expression, whereas KCC2 was undetectable. During a hypotonic challenge, KCC1 membrane content increased more rapidly in HCEC than in RCEC. Such a challenge induced a larger increase and more transient p44/42MAPK activation in HCEC than RCEC. On the other hand, HCEC and RCEC p38MAPK phosphorylation reached peak activations at 2.5 and 15 min, respectively. Only in HCEC, pharmacological manipulation of KCC activity modified the hypotonicity-induced activation of p44/42MAPK, whereas p38MAPK phosphorylation was insensitive to such procedures in both cell lines. Larger increases in HCEC KCC1 membrane protein content correlate with their ability to undergo faster and more complete RVD. Furthermore, pharmacological activation of KCC increased p44/42MAPK phosphorylation in HCEC but not in RCEC, presumably a reflection of low KCC membrane expression in RCEC. These findings suggest that KCC1 plays a role in (i) maintaining isotonic steady-state cell volume homeostasis, (ii) recovery of isotonic cell volume after a hypotonic challenge through RVD, and (iii) regulating hypotonicity-induced activation of the p44/42MAPK signaling pathway required for cell proliferation. PMID:17418819

Diethylcarbamazine attenuates the expression of pro-fibrogenic markers and hepatic stellate cells activation in carbon tetrachloride-induced liver fibrosis.

PubMed

França, Maria Eduarda Rocha de; Rocha, Sura Wanessa Santos; Oliveira, Wilma Helena; Santos, Laise Aline; de Oliveira, Anne Gabrielle Vasconcelos; Barbosa, Karla Patrícia Sousa; Nunes, Ana Karolina Santana; Rodrigues, Gabriel Barros; Lós, Deniele Bezerra; Peixoto, Christina Alves

2018-04-01

While diethylcarbamazine citrate (DEC) displays important anti-inflammatory effects in experimental models of liver injury, the mechanisms of its action remain poorly understood. The aim of the present study was to investigate the fibrolytic potential of DEC. Mice receive two injections of carbon tetrachloride (CCl 4 ) per week for 8 weeks. DEC 50 mg/kg body weight was administered through drinking water during the last 12 days of liver injury. The expression of hepatic stellate cells (HSCs) activation markers, including smooth muscle α-actin (α-SMA), collagen I, transforming growth factor-β 1 (TGF-β1), matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) was assessed. The influence of DEC on the intracellular MAPK pathways of the HSCs (JNK and p38 MAPK) was also estimated. DEC inhibited HSCs activation measured as the production of α-SMA and collagen I. In addition, it down regulated the production of TGF-β1 and TIMP-1, and concomitantly increased MMP-2 activity. Furthermore, DEC significantly inhibited the activation of the JNK and p38 MAPK signaling pathways. In conclusion, DEC significantly attenuated the severity of CCl 4 -induced liver injury and the progression of liver fibrosis, exerting a potential fibrolytic effect in the CCl 4 -induced fibrosis model.

Induction of keratinocyte migration by ECa 233 is mediated through FAK/Akt, ERK, and p38 MAPK signaling.

PubMed

Singkhorn, Sawana; Tantisira, Mayuree H; Tanasawet, Supita; Hutamekalin, Pilaiwanwadee; Wongtawatchai, Tulaporn; Sukketsiri, Wanida

2018-03-13

Centella asiatica is widely considered the most important medicinal plant for treating and relieving skin diseases. Recently developed standardized extract of Centella asiatica ECa 233 has demonstrated positive effects on wound healing of incision and burn wound in rats. However, knowledge associated with wound healing mechanism of ECa 233 was scare. Therefore, this study aimed to investigate the effect and underlying molecular mechanisms of ECa 233 on the migration of a human keratinocyte cell line (HaCaT) using scratch wound healing assay. Formation of filopodia, a key protein in cell migration as well as signaling pathways possibly involved were subsequently assessed. It was found that HaCaT cell migration was significantly enhanced by ECa 233 in a concentration- and time-dependent manner. The filopodia formations were accordingly increased in exposure to ECa 233 at concentrations of 0.1-100 μg/ml. Furthermore, ECa 233 was found to significantly upregulate the expression of Rac1 and RhoA and to induce phosphorylation of FAK and Akt as well as ERK and p38 MAPK. Taken all together, it is suggestive that ECa 233 induces cell migration and subsequently promotes wound healing activity, through the activation of FAK, Akt, and MAPK signaling pathways thereby supporting the role of ECa 233 to be further developed for the clinical treatment of wound. Copyright © 2018 John Wiley & Sons, Ltd.

Immunomodulatory Activity of Ganoderma atrum Polysaccharide on Purified T Lymphocytes through Ca2+/CaN and Mitogen-Activated Protein Kinase Pathway Based on RNA Sequencing.

PubMed

Xiang, Quan-Dan; Yu, Qiang; Wang, Hui; Zhao, Ming-Ming; Liu, Shi-Yu; Nie, Shao-Ping; Xie, Ming-Yong

2017-07-05

Our previous study has demonstrated that Ganoderma atrum polysaccharide (PSG-1) has immunomodulatory activity on spleen lymphocytes. However, how PSG-1 exerts its effect on purified lymphocytes is still obscure. Thus, this study aimed to investigate the immunomodulatory activity of PSG-1 on purified T lymphocytes and further elucidate the underlying mechanism based on RNA sequencing (RNA-seq). Our results showed that PSG-1 promoted T lymphocytes proliferation and increased the production of IL-2, IFN-γ, and IL-12. Meanwhile, RNA-seq analysis found 394 differentially expressed genes. KEGG pathway analysis identified 20 significant canonical pathways and seven biological functions. Furthermore, PSG-1 elevated intracellular Ca 2+ concentration and calcineurin (CaN) activity and raised the p-ERK, p-JNK, and p-p38 expression levels. T lymphocytes proliferation and the production of IL-2, IFN-γ, and IL-12 were decreased by the inhibitors of calcium channel and mitogen-activated protein kinases (MAPKs). These results indicated that PSG-1 possesses immunomodulatory activity on purified T lymphocytes, in which Ca 2+ /CaN and MAPK pathways play essential roles.

Fluoxetine signature on hippocampal MAPK signalling in sex-dependent manner.

PubMed

Mitic, Milos; Lukic, Iva; Bozovic, Natalija; Djordjevic, Jelena; Adzic, Miroslav

2015-02-01

A growing body of evidence indicates that mitogen-activated protein kinase (MAPK) participates in various stress-induced responses and is considered to be one of the pathophysiological mechanisms in depression. Surprisingly, the effect of antidepressants on MAPKs is almost unexplored, particularly from the perspective of sexes. The present study investigates the cytoplasm-nuclear distribution of MAPK family, c-Jun N-terminal kinases (JNKs) 1, 2 and 3; extracellular signal-regulated kinases (ERKs) 1 and 2; and p38 kinases, as well as their phosphoisoforms in the hippocampus of chronically stressed female and male rats and upon chronic fluoxetine treatment. Additionally, we analysed crosstalk between MAPK signalling and depressive-like behaviour which correlated with brain-derived neurotrophic factor (BDNF) expression. Our results emphasize a gender-specific and compartment-dependent response of MAPKs to stress and fluoxetine. In females, stress decreased pp38 and pJNK and induced cytosolic retention of pERKs which reduced all nuclear pMAPKs. These changes correlated with altered BDNF expression and behaviour. Similarly, in males, stress decreased pp38 but promoted nuclear translocation of pJNKs and pERKs. These stress alterations of pMAPKs in males were not associated with BDNF expression and depressive-like behaviour. Fluoxetine treatment in stressed females upregulated whole pMAPK signalling particularly those in nucleus which was followed with BDNF expression and normalization of behaviour. In stressed males, fluoxetine affected only cytosolic pJNKs, while nuclear pMAPK signalling and BDNF expression were unaffected even though fluoxetine normalized behaviour. Overall, our results suggest existence of gender-specific mechanism of fluoxetine on nuclear pMAPK/BDNF signalling and depressive-like behaviour and reinforce the antidepressant dogma that females and males respond differently to certain antidepressants.

A sestrin-dependent Erk/Jnk/p38 MAPK activation complex inhibits immunity during ageing

PubMed Central

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

2016-01-01

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 co-ordinate 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 only allowed partial functional recovery. T cells from old humans and mice 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 ageing. PMID:28114291

Characterization of p38 MAPK isoforms for drug resistance study using systems biology approach.

PubMed

Peng, Huiming; Peng, Tao; Wen, Jianguo; Engler, David A; Matsunami, Risë K; Su, Jing; Zhang, Le; Chang, Chung-Che Jeff; Zhou, Xiaobo

2014-07-01

p38 mitogen-activated protein kinase activation plays an important role in resistance to chemotherapeutic cytotoxic drugs in treating multiple myeloma (MM). However, how the p38 mitogen-activated protein kinase signaling pathway is involved in drug resistance, in particular the roles that the various p38 isoforms play, remains largely unknown. To explore the underlying mechanisms, we developed a novel systems biology approach by integrating liquid chromatography-mass spectrometry and reverse phase protein array data from human MM cell lines with computational pathway models in which the unknown parameters were inferred using a proposed novel algorithm called modularized factor graph. New mechanisms predicted by our models suggest that combined activation of various p38 isoforms may result in drug resistance in MM via regulating the related pathways including extracellular signal-regulated kinase (ERK) pathway and NFкB pathway. ERK pathway regulating cell growth is synergistically regulated by p38δ isoform, whereas nuclear factor kappa B (NFкB) pathway regulating cell apoptosis is synergistically regulated by p38α isoform. This finding that p38δ isoform promotes the phosphorylation of ERK1/2 in MM cells treated with bortezomib was validated by western blotting. Based on the predicted mechanisms, we further screened drug combinations in silico and found that a promising drug combination targeting ERK1/2 and NFκB might reduce the effects of drug resistance in MM cells. This study provides a framework of a systems biology approach to studying drug resistance and drug combination selection. RPPA experimental Data and Matlab source codes of modularized factor graph for parameter estimation are freely available online at http://ctsb.is.wfubmc.edu/publications/modularized-factor-graph.php. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Molecular Cloning and Characterization of a P38-Like Mitogen-Activated Protein Kinase from Echinococcus granulosus.

PubMed

Lü, Guodong; Li, Jing; Zhang, Chuanshan; Li, Liang; Bi, Xiaojuan; Li, Chaowang; Fan, Jinliang; Lu, Xiaomei; Vuitton, Dominique A; Wen, Hao; Lin, Renyong

2016-12-01

Cystic echinococcosis (CE) treatment urgently requires a novel drug. The p38 mitogen-activated protein kinases (MAPKs) are a family of Ser/Thr protein kinases, but still have to be characterized in Echinococcus granulosus . We identified a 1,107 bp cDNA encoding a 368 amino acid MAPK protein (Egp38) in E. granulosus . Egp38 exhibits 2 distinguishing features of p38-like kinases: a highly conserved T-X-Y motif and an activation loop segment. Structural homology modeling indicated a conserved structure among Egp38, EmMPK2, and H. sapiens p38α, implying a common binding mechanism for the ligand domain and downstream signal transduction processing similar to that described for p38α. Egp38 and its phosphorylated form are expressed in the E. granulosus larval stages vesicle and protoscolices during intermediate host infection of an intermediate host. Treatment of in vitro cultivated protoscolices with the p38-MAPK inhibitor ML3403 effectively suppressed Egp38 activity and led to significant protoscolices death within 5 days. Treatment of in vitro-cultivated protoscolices with TGF-β1 effectively induced Egp38 phosphorylation. In summary, the MAPK, Egp38, was identified in E. granulosus , as an anti-CE drug target and participates in the interplay between the host and E. granulosus via human TGF-β1.

Phosphorylation of the Grb2- and phosphatidylinositol 3-kinase p85-binding p36/38 by Syk in Lck-negative T cells.

PubMed

von Willebrand, M; Williams, S; Tailor, P; Mustelin, T

1998-06-01

Activation of the mitogen-activated protein kinase (MAPK) pathway by the T-cell antigen receptor (TCR) in T cells involves a positive role for phosphatidylinositol 3-kinase (PI3K) activity. We recently reported that over-expression of the Syk protein tyrosine kinase in the Lck-negative JCaM1 cells enabled the TCR to induce a normal activation of the Erk2 MAPK and enhanced transcription of a reporter gene driven by the nuclear factor of activated T cells and AP-1. Because this system allows us to analyse the targets for Syk in receptor-mediated signalling, we examined the role of PI3K in signalling events between the TCR-regulated Syk and the downstream activation of Erk2. We report that inhibition of PI3K by wortmannin or an inhibitory p85 construct, p85deltaiSH2, reduced the TCR-induced Syk-dependent activation of Erk2, as well as the appearance of phospho-Erk and phospho-Mek. At the same time, expression of Syk resulted in the activation-dependent phosphorylation of three proteins that bound to the src homology 2 (SH2) domains of PI3K p85. The strongest of these bands had an apparent molecular mass of 36-38 kDa on SDS gels, and it was quantitatively removed from the lysates by adsorption to a fusion protein containing the SH2 domain of Grb2. The appearance of this band was Syk dependent, and it was seen only upon triggering of the TCR complex. Thus, p36/38 was phosphorylated by Syk or a Syk-regulated kinase, and this protein may provide a link to the recruitment and activation of PI3K, as well as to the Ras-MAPK pathway, in TCR-triggered T cells.

[Effect of limb ischemic preconditioning on the expression of p38 MAPK and HSP 70 in CA3 and DG regions of the hippocampus of rats].

PubMed

Sun, Xiao-Cai; Li, Wen-Bin; Zhao, Li; Jia, Hui-Xian; Wang, Fang; Zhang, Min; Li, Shu-Qin

2013-01-01

To observe the expression of p38 MAPK and HSP 70 in CA3 and dentate gyrus (DG) regions of the hippocampus of rats induced by limb ischemic preconditioning (LIP). Ninety-six rats were randomly divided into sham and LIP groups. And the animals in the LIP group were further divided into LIP 6 h, LIP 12 h, LIP 1 d, LIP 2 d, LIP 3 d, LIP 4 d and LIP 5 d subgroups according to the time of reperfusion after LIP. Immunohistochemical staining and Western blot were used to observe the expression of p38 MAPK and HSP 70 in CA3 and DG regions of the hippocampus. The results of the immunohistochemical staining and Western blot were consistent, which indicated that there were fluctuation in the p-p38 MAPK and HSP 70 expression in CA3 and DG regions after LIP compared with those of the sham group. The expression of p-p38 MAPK began to be up-regulated 1d after LIP and reached its peak at 3 d and lasted for 4 d after LIP. However, the expression of HSP 70 was significantly up-regulated 2 d after LIP compared to the sham group, reached its peak at 3 d and lasted until the 4 d after LIP. LIP up-regulates the expression of p38 MAPK and HSP 70 in the CA3 and DG regions of the hippocampus of rats.

Edaravone Prevents Retinal Degeneration in Adult Mice Following Optic Nerve Injury.

PubMed

Akiyama, Goichi; Azuchi, Yuriko; Guo, Xiaoli; Noro, Takahiko; Kimura, Atsuko; Harada, Chikako; Namekata, Kazuhiko; Harada, Takayuki

2017-09-01

To assess the therapeutic potential of edaravone, a free radical scavenger that is used for the treatment of acute brain infarction and amyotrophic lateral sclerosis, in a mouse model of optic nerve injury (ONI). Two microliters of edaravone (7.2 mM) or vehicle were injected intraocularly 3 minutes after ONI. Optical coherence tomography, retrograde labeling of retinal ganglion cells (RGCs), histopathology, and immunohistochemical analyses of phosphorylated apoptosis signal-regulating kinase-1 (ASK1) and p38 mitogen-activated protein kinase (MAPK) in the retina were performed after ONI. Reactive oxygen species (ROS) levels were assessed with a CellROX Green Reagent. Edaravone ameliorated ONI-induced ROS production, RGC death, and inner retinal degeneration. Also, activation of the ASK1-p38 MAPK pathway that induces RGC death following ONI was suppressed with edaravone treatment. The results of this study suggest that intraocular administration of edaravone may be a useful treatment for posttraumatic complications.

Thrombomodulin exerts cytoprotective effect on low-dose UVB-irradiated HaCaT cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iwata, Masahiro; Laboratory of Vascular Medicine, Department of Cardiovascular and Respiratory Disorders Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520; Kawahara, Ko-ichi

Thrombomodulin (TM) is an endothelial cell surface anticoagulant glycoprotein that performs antimetastatic, angiogenic, adhesive, and anti-inflammatory functions in various tissues. It is also expressed in epidermal keratinocytes. We found that a physiological dose (10 mJ/cm{sup 2}) of mid-wavelength ultraviolet irradiation (UVB) significantly induced TM expression via the p38mitogen-activated protein kinase (MAPK)/cyclic AMP response element (CRE) signaling pathway in the epidermal keratinocyte cell line HaCaT; this shows that TM regulates the survival of HaCaT cells. SB203580, a p38MAPK inhibitor, significantly decreased TM expression and the viability of cells exposed to UVB. Furthermore, overexpression of TM markedly increased cell viability, and itmore » was abrogated by TM small interfering RNA (siRNA), suggesting that TM may play an important role in exerting cytoprotective effect on epidermal keratinocytes against low-dose UVB.« less

[Effect of Medicated-catgut Embedding at "Changqiang" (GV 1) on Mechanical Pain Threshold and P 38 MAPK Expression in Spinal Cord Tissue in Anus Incisional Pain Rats].

PubMed

Shu, Tao; Zhang, Shi-Ti; Yan, Feng; Ke, Yu-Pei; Wang, Jun

2017-10-25

To observe the effect of medicated-catgut embedding at "Changqiang"(GV 1) on regional pain reaction and expression of p 38 MAPK in the dorsal horn of spinal cord in anus incisional pain rats, so as to explore its analgesic mechanism. Forty male SD rats were randomly divided into control, model, GV 1-embedding and sham acupoint embedding groups ( n =10 rats in each group). The anus incisional pain model was established by making a radial incision (about 10 mm length) at the left lithotomy position of the anus with a surgical knife, and the mechanical pain threshold (PT) was measured by using a Von Frey before and 4, 8, 12, 24 h after operation. The medicated-catgut (about 12.5 mm length/kg body weight) was implanted in the subcutaneous tissue of GV 1 region. The immunoactivity of p 38 MAPK was determined by immunohistochemistry. Compared with the control group, the mechanical PTs were significantly decreased 4, 8, 12 and 24 h after operation both at the site of incision and about 15 mm proximal to the site of incision in the model group ( P <0.05), and the immunoactivity of phosphorylated (p)-p 38 MAPK in the superficial layer of dorsal horns of lumbar spinal cord was significantly increased(24 h)after operation( P <0.05). Compared with the model group, the PTs were significantly increased 8, 12 and 24 h after operation at the site of incision, and 12 h and 24 h at the site about 15 mm proximal to the incision region ( P <0.05), and the immunoactivity level of p-p 38 MAPK was significantly down-regulated in the GV 1-embedding group ( P <0.05). No significant changes were found in the PT and p-p 38 MAPK immunoactivity levels in the sham acupoint embedding group ( P <0.05). Medicated-catgut embedding at "Changqiang"(GV 1) has an analgesic effect in anus incisional pain model rats, which may be related to its effect in down-regulating the expression of p 38 MAPK in the dorsal horn of lumbar spinal cord.

N-hydroxycinnamide derivatives of osthole ameliorate hyperglycemia through activation of AMPK and p38 MAPK.

PubMed

Lee, Wei-Hwa; Wu, Hsueh-Hsia; Huang, Wei-Jan; Li, Yi-Ning; Lin, Ren-Jye; Lin, Shyr-Yi; Liang, Yu-Chih

2015-03-11

Our previous studies found that osthole markedly reduced blood glucose levels in both db/db and ob/ob mice. To improve the antidiabetic activity of osthole, a series of N-hydroxycinnamide derivatives of osthole were synthesized, and their hypoglycemia activities were examined in vitro and in vivo. Both N-hydroxycinnamide derivatives of osthole, OHC-4p and OHC-2m, had the greatest potential for activating AMPK and increasing glucose uptake by L6 skeletal muscle cells. In addition, OHC-4p and OHC-2m time- and dose-dependently increased phosphorylation levels of AMPK and p38 MAPK. The AMPK inhibitor, compound C, and the p38 MAPK inhibitor, SB203580, significantly reversed activation of AMPK and p38 MAPK, respectively, in OHC-4p- and OHC-2m-treated cells. Compound C and SB203580 also inhibited glucose uptake induced by OHC-4p and OHC-2m. Next, we found that OHC-4p and OHC-2m significantly increased glucose transporter 4 (GLUT4) translocation to plasma membranes and counteracted hyperglycemia in mice with streptozotocin-induced diabetes. These results suggest that activation of AMPK and p38 MAPK by OHC-4p and OHC-2m is associated with increased glucose uptake and GLUT4 translocation and subsequently led to amelioration of hyperglycemia. Therefore, OHC-4p and OHC-2m might have potential as antidiabetic agents for treating type 2 diabetes. Our previous studies found that osthole markedly reduced blood glucose levels in both db/db and ob/ob mice. To improve the antidiabetic activity of osthole, a series of N-hydroxycinnamide derivatives of osthole were synthesized, and their hypoglycemia activities were examined in vitro and in vivo. Both N-hydroxycinnamide derivatives of osthole, OHC-4p and OHC-2m, had the greatest potential for activating AMPK and increasing glucose uptake by L6 skeletal muscle cells. In addition, OHC-4p and OHC-2m time- and dose-dependently increased phosphorylation levels of AMPK and p38 MAPK. The AMPK inhibitor, compound C, and the p38 MAPK inhibitor, SB203580, significantly reversed activation of AMPK and p38 MAPK, respectively, in OHC-4p- and OHC-2m-treated cells. Compound C and SB203580 also inhibited glucose uptake induced by OHC-4p and OHC-2m. Next, we found that OHC-4p and OHC-2m significantly increased glucose transporter 4 (GLUT4) translocation to plasma membranes and counteracted hyperglycemia in mice with streptozotocin-induced diabetes. These results suggest that activation of AMPK and p38 MAPK by OHC-4p and OHC-2m is associated with increased glucose uptake and GLUT4 translocation and subsequently led to amelioration of hyperglycemia. Therefore, OHC-4p and OHC-2m might have potential as antidiabetic agents for treating type 2 diabetes.

Regulation of HtrA2 on WT1 gene expression under imatinib stimulation and its effects on the cell biology of K562 cells.

PubMed

Zhang, Lixia; Li, Yan; Li, Xiaoyan; Zhang, Qing; Qiu, Shaowei; Zhang, Qi; Wang, Min; Xing, Haiyan; Rao, Qing; Tian, Zheng; Tang, Kejing; Wang, Jianxiang; Mi, Yingchang

2017-09-01

The aim of the present study was to investigate the regulation of Wilms Tumor 1 (WT1) by serine protease high-temperature requirement protein A2 (HtrA2), a member of the Htr family, in K562 cells. In addition, the study aimed to observe the effect of this regulation on cell biological functions and its associated mechanisms. Expression of WT1 and HtrA2 mRNA, and proteins following imatinib and the HtrA2 inhibitor 5-[5-(2-nitrophenyl) furfuryl iodine]-1, 3-diphenyl-2-thiobarbituric acid (UCF-101) treatment was detected with reverse transcription-quantitative polymerase chain reaction and western blot analysis. Subsequent to treatment with drugs and UCF-101, the proliferative function of K562 cells was detected using MTT assays, and the rate of apoptosis was detected using Annexin V with propidium iodide flow cytometry in K562 cells. The protein levels in the signaling pathway were analyzed using western blotting following treatment with imatinib and UCF-101. In K562 cells, imatinib treatment activated HtrA2 gene at a transcription level, while the WT1 gene was simultaneously downregulated. Following HtrA2 inhibitor (UCF-101) treatment, the downregulation of WT1 increased gradually. At the protein level, imatinib induced the increase in HtrA2 protein level and concomitantly downregulated WT1 protein level. Subsequent to HtrA2 inhibition by UCF-101, the WT1 protein level decreased temporarily, but eventually increased. Imatinib induced apoptosis in K562 cells, but this effect was attenuated by the HtrA2 inhibitor UCF-101, resulting in the upregulation of the WT1 protein level. However; UCF-101 did not markedly change the proliferation inhibition caused by imatinib. Imatinib activated the p38 mitogen activated protein kinase (p38 MAPK) signaling pathway in K562 cells, and UCF-101 affected the activation of imatinib in the p38 MAPK signaling pathway. Imatinib inhibited the extracellular signal-related kinase (ERK1/2) pathway markedly and persistently, but UCF-101 exhibited no notable effect on the inhibition of the ERK1/2 pathway. HtrA2 and its regulatory effect on WT1 may affect the sensitivity of BCR/ABL(+) cell lines to target therapy drugs through different mechanisms. Regulation of WT1 by HtrA2 occurs in K562 cells, and the regulation may affect the apoptosis of K562 cells under the stress caused by chemotherapeutic treatment. The p38 MAPK signaling pathway, which serves an important role in cell apoptosis, is a downstream pathway of this regulation.

Effect of music therapy on pain behaviors in rats with bone cancer pain.

PubMed

Gao, Ji; Chen, Shaoqin; Lin, Suyong; Han, Hongjing

2016-01-01

To investigate the effects of music therapy on the pain behaviors and survival of rats with bone cancer pain and analyze the mediating mechanism of mitogen activated protein kinase (MAPK) signal transduction pathway. Male Wistar rats aged 5-8 weeks and weighing 160-200 g were collected. The rat models of colorectal cancer bone cancer pain was successfully established. Animals were divided into experimental and control group, each with 10 rats. The animals in the observation group were given Mozart K448 sonata, sound intensity of 60 db, played the sonata once every 1 hr in the daytime, stopped playing during the night, and this cycle was kept for 2 weeks. On the other hand, rats in the control group were kept under the same environment without music. Animals in the experimental group consumed more feed and gained significant weight in comparison to the control group. The tumor volume of the experimental group was significantly smaller than that of the control group (p<0.05). After 1-2 weeks of treatment, spontaneous foot withdrawal reflection caused by pain in the experimental group was significantly lower than that in the control group, heat pain threshold and free walking pain scoring in the experimental group were also significantly higher as compared with the control group (p<0.05). The expression of p38á and p38β in animals' spinal cord and dorsal root ganglion was significantly lower in the experimental group than in the control group (p< 0.05). Music therapy may improve the pain behaviors in rats with bone cancer pain, which might be related with low expression of p38á and p38β in the MAPK signal transduction pathway.

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

PubMed

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

2015-11-01

1,2-Diarachidonoyl-sn-glycero-3-phosphoethanolamine (DAPE) induces both necrosis/necroptosis and apoptosis of NCI-H28 malignant pleural mesothelioma (MPM) cells. The present study was conducted to understand the mechanism for DAPE-induced apoptosis of NCI-H28 cells. DAPE induced caspase-independent apoptosis of NCI-H28 malignant pleural mesothelioma (MPM) cells, and the effect of DAPE was prevented by antioxidants or an inhibitor of NADPH oxidase (NOX). DAPE generated reactive oxygen species (ROS) and inhibited activity of thioredoxin (Trx) reductase (TrxR). DAPE decreased an association of apoptosis signal-regulating kinase 1 (ASK1) with thioredoxin (Trx), thereby releasing ASK1. DAPE activated p38 mitogen-activated protein kinase (MAPK), which was inhibited by an antioxidant or knocking-down ASK1. In addition, DAPE-induced NCI-H28 cell death was also prevented by knocking-down ASK1. Taken together, the results of the present study indicate that DAPE stimulates NOX-mediated ROS production and suppresses TrxR activity, resulting in the decrease of reduced Trx and the dissociation of ASK1 from a complex with Trx, allowing sequential activation of ASK1 and p38 MAPK, to induce apoptosis of NCI-H28 MPM cells. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Lysosome trafficking is necessary for EGF-driven invasion and is regulated by p38 MAPK and Na+/H+ exchangers.

PubMed

Dykes, Samantha S; Steffan, Joshua J; Cardelli, James A

2017-10-04

Tumor invasion through a basement membrane is one of the earliest steps in metastasis, and growth factors, such as Epidermal Growth Factor (EGF) and Hepatocyte Growth Factor (HGF), stimulate this process in a majority of solid tumors. Basement membrane breakdown is one of the hallmarks of invasion; therefore, tumor cells secrete a variety of proteases to aid in this process, including lysosomal proteases. Previous studies demonstrated that peripheral lysosome distribution coincides with the release of lysosomal cathepsins. Immunofluorescence microscopy, western blot, and 2D and 3D cell culture techniques were performed to evaluate the effects of EGF on lysosome trafficking and cell motility and invasion. EGF-mediated lysosome trafficking, protease secretion, and invasion is regulated by the activity of p38 mitogen activated protein kinase (MAPK) and sodium hydrogen exchangers (NHEs). Interestingly, EGF stimulates anterograde lysosome trafficking through a different mechanism than previously reported for HGF, suggesting that there are redundant signaling pathways that control lysosome positioning and trafficking in tumor cells. These data suggest that EGF stimulation induces peripheral (anterograde) lysosome trafficking, which is critical for EGF-mediated invasion and protease release, through the activation of p38 MAPK and NHEs. Taken together, this report demonstrates that anterograde lysosome trafficking is necessary for EGF-mediated tumor invasion and begins to characterize the molecular mechanisms required for EGF-stimulated lysosome trafficking.

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

PubMed Central

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

2015-01-01

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