scholarly journals Stimulation of cardiac fibroblast Piezo1 channels opposes myofibroblast differentiation and induces IL-6 secretion via Ca2+-mediated p38 MAP kinase activation

2019 ◽  
Author(s):  
Nicola M. Blythe ◽  
Vasili Stylianidis ◽  
Melanie J. Ludlow ◽  
Hamish T. J. Gilbert ◽  
Elizabeth L. Evans ◽  
...  
Keyword(s):  
Map Kinase ◽  
Structural Integrity ◽  
Kinase Inhibitor ◽  
Cardiac Fibroblasts ◽  
Collagen Gel ◽  
Mechanical Stretch ◽  
Cardiac Fibroblast ◽  
Ruthenium Red ◽  
P38 Map Kinase ◽  
Dependent Manner

AbstractPiezo1 is a mechanosensitive cation channel with widespread physiological importance; however its role in the heart is poorly understood. Cardiac fibroblasts are responsible for preserving the structural integrity of the myocardium and play a key role in regulating its repair and remodeling following stress or injury. We investigated expression and function of Piezo1 in cultured human and mouse cardiac fibroblasts. RT-PCR studies confirmed expression ofPiezo1mRNA in cardiac fibroblasts at similar levels to endothelial cells. Fura-2 intracellular Ca2+measurements validated Piezo1 as a functional ion channel that was activated by the Piezo1 agonist, Yoda1. Yoda1-induced Ca2+entry was inhibited by Piezo1 blockers (gadolinium, ruthenium red) and the Ca2+response was reduced proportionally by Piezo1 siRNA knockdown or in cells fromPiezo1+/−mice. Investigation of Yoda1 effects on selected remodeling genes indicated that Piezo1 activation opposed cardiac fibroblast differentiation; data confirmed by functional collagen gel contraction assays. Piezo1 activation using Yoda1 or mechanical stretch also increased the expression of interleukin-6 (IL-6), a mechanosensitive pro-hypertrophic and pro-fibrotic cytokine, in a Piezo1-dependent manner. Multiplex kinase activity profiling combined with kinase inhibitor studies and phospho-specific western blotting, established that Piezo1 activation stimulated IL-6 secretion via a pathway involving p38 MAP kinase, downstream of Ca2+entry. In summary, this study reveals that cardiac fibroblasts express functional Piezo1 channels coupled to reduced myofibroblast activation and increased secretion of paracrine signaling molecules that can modulate cardiac remodeling.

scholarly journals Mechanisms underlying modulation of monocarboxylate transporter 1 (MCT1) by somatostatin in human intestinal epithelial cells

2009 ◽  
Vol 297 (5) ◽  
pp. G878-G885 ◽  
Author(s):  
Seema Saksena ◽  
Saritha Theegala ◽  
Nikhil Bansal ◽  
Ravinder K. Gill ◽  
Sangeeta Tyagi ◽  
...  
Keyword(s):  
Map Kinase ◽  
Kinase Inhibitor ◽  
Apical Membrane ◽  
P38 Map Kinase ◽  
Monocarboxylate Transporter ◽  
Maximal Velocity ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
Human Intestine ◽  
Monocarboxylate Transporter 1

Somatostatin (SST), an important neuropeptide of the gastrointestinal tract has been shown to stimulate sodium chloride absorption and inhibit chloride secretion in the intestine. However, the effects of SST on luminal butyrate absorption in the human intestine have not been investigated. Earlier studies from our group and others have shown that monocarboxylate transporter (MCT1) plays an important role in the transport of butyrate in the human intestine. The present studies were undertaken to examine the effects of SST on butyrate uptake utilizing postconfluent human intestinal epithelial Caco2 cells. Apical SST treatment of Caco-2 cells for 30–60 min significantly increased butyrate uptake in a dose-dependent manner with maximal increase at 50 nM (∼60%, P < 0.05). SST receptor 2 agonist, seglitide, mimicked the effects of SST on butyrate uptake. SST-mediated stimulation of butyrate uptake involved the p38 MAP kinase-dependent pathway. Kinetic studies demonstrated that SST increased the maximal velocity ( Vmax) of the transporter by approximately twofold without any change in apparent Michaelis-Menten constant ( Km). The higher butyrate uptake in response to SST was associated with an increase in the apical membrane levels of MCT1 protein parallel to a decrease in the intracellular MCT1 pool. MCT1 has been shown to interact specifically with CD147 glycoprotein/chaperone to facilitate proper expression and function of MCT1 at the cell surface. SST significantly enhanced the membrane levels of CD147 as well as its association with MCT1. This association was completely abolished by the specific p38 MAP kinase inhibitor, SB203580. Our findings demonstrate that increased MCT1 association with CD147 at the apical membrane in response to SST is p38 MAP kinase dependent and underlies the stimulatory effects of SST on butyrate uptake.

scholarly journals Inhibitory effects of adiponectin on platelet-derived growth factor-induced mesangial cell migration

2009 ◽  
Vol 202 (2) ◽  
pp. 309-316 ◽  
Author(s):  
Keisuke Ishizawa ◽  
Narantungalag Dorjsuren ◽  
Yuki Izawa-Ishizawa ◽  
Rika Sugimoto ◽  
Yasumasa Ikeda ◽  
...  
Keyword(s):  
Cell Migration ◽  
Growth Factor ◽  
Map Kinase ◽  
Intracellular Signaling ◽  
Mesangial Cell ◽  
Kinase Inhibitor ◽  
P38 Map Kinase ◽  
Platelet Derived Growth Factor ◽  
Dependent Manner ◽  
Plasma Adiponectin

Adiponectin, an adipocyte-derived hormone, has been involved in metabolic syndrome, a known risk factor for the development of chronic kidney disease (CKD). Recent studies have demonstrated that plasma adiponectin levels are elevated when kidney function declines in patients with CKD. Excessive mesangial cell (MC) turnover is one of the important features of CKD. The aim of the present study is to elucidate the effects of adiponectin on platelet-derived growth factor (PDGF)-induced cell migration and intracellular signaling pathways, in cultured rat MCs (RMCs). PDGF-induced RMC migration was significantly inhibited by the pretreatment of adiponectin. Adiponectin alone had no effect on RMC migration. Big mitogen-activated protein (MAP) kinase 1 (BMK1), p38 MAP kinase, and Akt were activated by PDGF stimulation in a time- and concentration-dependent manner in RMC. Adiponectin alone did not affect BMK1, p38 MAP kinase, and Akt phosphorylations in RMC. PDGF-induced BMK1 and p38 MAP kinase phosphorylations were significantly attenuated by the pretreatment of adiponectin in RMCs. On the other hand, the phosphorylation of Akt by PDGF was not diminished by the pretreatment of adiponectin. Adiponectin had no effects on PDGF-receptor autophosphorylation by PDGF. We also confirmed that PDGF-induced RMC migration was significantly suppressed by siBMK1 transfection or SB203580, a p38 MAP kinase inhibitor. From these findings, it is implied that the elevated plasma adiponectin levels in patients with CKD might play a compensatory role aimed at counteracting renal dysfunction related to MC disorders.

scholarly journals Cycloartenyl Ferulate downregulates lipopolysaccharide stimulated iNOS mRNA via NF-kB suppression in RAW 264.7 macrophages

2017 ◽  
Vol 2 (4) ◽  
pp. 523-531 ◽  
Author(s):  
Md Shafiqul Islam ◽  
Hideki Ushio ◽  
Masatoshi Hori ◽  
Hiroshi Ozaki
Keyword(s):  
Map Kinase ◽  
Nuclear Translocation ◽  
Kinase Inhibitor ◽  
P38 Map Kinase ◽  
Inos Mrna ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Raw 264.7 Macrophages ◽  
Cox 2 ◽  
Dose Dependent

Cycloartenyl ferulate (CAF) is a major bioactive phytosteryl ferulate purified from rice bran ?- oryzanol. Previously we reported that CAF ameliorates DSS-induced colitis in mice. The present study was undertaken to investigate the effects of CAF on LPS (lipopolysaccharide) stimulated murine RAW 264.7 macrophages. Immunohistochemistry analysis demonstrated that LPS (10ng/mL) treatment exhibited nuclear translocation of NF-?B-p65 in RAW macrophages, which was markedly inhibited CAF (30?M). LPS (10ng/mL) stimulation for 1-4 hours significantly upregulated iNOS and COX-2 mRNA in RAW 264.7 macrophages, but COX-2 mRNA was faster than that of iNOS mRNA. Macrophages pretreated with CAF greatly inhibited the LPS stimulated iNOS mRNA in a dose dependent manner (1-30?M), but CAF weakly inhibited COX-2 mRNA. Interestingly, CAY 10404 (COX-2 inhibitor) inhibited LPS stimulated iNOS mRNA, but not COX-2. In addition, PGE2 (1?M) upregulated iNOS mRNA but did not show any remarkable effects on NF-?B-p65 nuclear translocation in RAW macrophages. PD98059 (p44/42 MAP kinase inhibitor) inhibited iNOS mRNA, but not COX-2. On the other hand, PD169316 (p38 MAP kinase inhibitor) neither inhibited iNOS mRNA nor COX-2. Our results suggest that iNOS mRNA expression by LPS is mediated via p44/42 MAP kinase pathway in RAW 264.7 macrophages, which depends on the preceding expression of COX-2 expression. CAF downregulates iNOS mRNA via an inhibition of nuclear translocation of NF-?B with different mode of action on COX-2 gene expression.Asian J. Med. Biol. Res. December 2016, 2(4): 523-531

scholarly journals Mechanically activated Piezo1 channels of cardiac fibroblasts stimulate p38 mitogen-activated protein kinase activity and interleukin-6 secretion

2019 ◽  
Vol 294 (46) ◽  
pp. 17395-17408 ◽  
Author(s):  
Nicola M. Blythe ◽  
Katsuhiko Muraki ◽  
Melanie J. Ludlow ◽  
Vasili Stylianidis ◽  
Hamish T. J. Gilbert ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Kinase Inhibitor ◽  
Cardiac Fibroblasts ◽  
Ruthenium Red ◽  
Mitogen Activated Protein Kinase ◽  
Protein Kinase Activity ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Mitogen Activated Protein

Piezo1 is a mechanosensitive cation channel with widespread physiological importance; however, its role in the heart is poorly understood. Cardiac fibroblasts help preserve myocardial integrity and play a key role in regulating its repair and remodeling following stress or injury. Here we investigated Piezo1 expression and function in cultured human and mouse cardiac fibroblasts. RT-PCR experiments confirmed that Piezo1 mRNA in cardiac fibroblasts is expressed at levels similar to those in endothelial cells. The results of a Fura-2 intracellular Ca2+ assay validated Piezo1 as a functional ion channel that is activated by its agonist, Yoda1. Yoda1-induced Ca2+ entry was inhibited by Piezo1 blockers (gadolinium and ruthenium red) and was reduced proportionally by siRNA-mediated Piezo1 knockdown or in murine Piezo1+/− cells. Results from cell-attached patch clamp recordings on human cardiac fibroblasts established that they contain mechanically activated ion channels and that their pressure responses are reduced by Piezo1 knockdown. Investigation of Yoda1 effects on selected remodeling genes indicated that Piezo1 activation increases both mRNA levels and protein secretion of IL-6, a pro-hypertrophic and profibrotic cytokine, in a Piezo1-dependent manner. Moreover, Piezo1 knockdown reduced basal IL-6 expression from cells cultured on softer collagen-coated substrates. Multiplex kinase activity profiling combined with kinase inhibitor experiments and phosphospecific immunoblotting established that Piezo1 activation stimulates IL-6 secretion via the p38 mitogen-activated protein kinase downstream of Ca2+ entry. In summary, cardiac fibroblasts express mechanically activated Piezo1 channels coupled to secretion of the paracrine signaling molecule IL-6. Piezo1 may therefore be important in regulating cardiac remodeling.

Mitochondrial ROS initiate phosphorylation of p38 MAP kinase during hypoxia in cardiomyocytes

2002 ◽  
Vol 282 (6) ◽  
pp. L1324-L1329 ◽  
Author(s):  
Andre Kulisz ◽  
Ningfang Chen ◽  
Navdeep S. Chandel ◽  
Zuohui Shao ◽  
Paul T. Schumacker
Keyword(s):  
Kinase Inhibitor ◽  
Anion Channel ◽  
P38 Map Kinase ◽  
Proximal Region ◽  
Mitogen Activated Protein Kinase ◽  
Ros Generation ◽  
Dependent Manner ◽  
Adaptive Responses ◽  
Mitochondrial Ros ◽  
Mitogen Activated Protein

The p38 mitogen-activated protein kinase (MAPK) is phosphorylated in response to oxidative stress. Mitochondria in cardiomyocytes increase their generation of reactive oxygen species (ROS) during hypoxia (1–5% O2). These ROS participate in signal transduction pathways involved in adaptive responses, including ischemic preconditioning and gene transcription. The present study therefore tested the hypothesis that hypoxia induces p38 MAPK phosphorylation by augmenting mitochondrial ROS generation. In cardiomyocytes, phosphorylation of p38 was observed in a Po 2-dependent manner during hypoxia. This response was inhibited by rotenone, thenoyltrifluoroacetone, and myxothiazol, inhibitors of mitochondrial complexes I, II, and III, respectively. A similar inhibition was observed in the cells pretreated with anion channel inhibitor DIDS, which may block ROS release from mitochondria. During normoxia, increases in mitochondrial ROS elicited by azide (1–2 mM) or by the mitochondrial inhibitor antimycin A caused increased phosphorylation of p38. Brief treatment with exogenous H2O2 during normoxia also induced phosphorylation of p38 as hypoxia, but this effect was not abolished by myxothiazol or DIDS. The antioxidant N-acetyl-cysteine abolished the p38 response to hypoxia, presumably by scavenging H2O2, but the mitogen extracellular receptor kinase inhibitor PD-98059 did not inhibit p38 phosphorylation during hypoxia. Thus physiological hypoxia leads to p38 phosphorylation through a mechanism that requires electron flux in the proximal region of the mitochondrial electron transport chain, which suggests that either H2O2 or superoxide participates in activating that process.

Abstract 372: The Smad3 Pathway Critically Regulates Myofibroblast Proliferation And Synthetic Activity In Healing Myocardial Infarcts

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Marcin Dobaczewski ◽  
Marcin Bujak ◽  
Carlos Gonzalez ◽  
Na Li ◽  
Xiao-Fan Wang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Extracellular Matrix ◽  
Proliferative Activity ◽  
Essential Role ◽  
Cardiac Fibroblasts ◽  
Cardiac Fibroblast ◽  
Synthetic Activity ◽  
Dependent Manner ◽  
Tenascin C ◽  
Infarcted Heart

We have recently demonstrated that the Transforming Growth Factor (TGF)-β/Smad3 pathway is activated in healing infarcts and plays an essential role in the pathogenesis of cardiac remodeling. Smad3 −/− mice were protected from the development of ventricular dilation following infarction and exhibited markedly reduced fibrosis of the peri-infarct area and the remodeling non-infarcted heart. Accordingly, we hypothesized that Smad3 signaling plays an essential role in regulating cardiac fibroblast function and gene expression in myocardial infarction. Surprisingly, Smad3 −/− infarcts exhibited increased peak infiltration with myofibroblasts, associated with evidence of enhanced proliferative activity. Smad3 −/− mice had a higher density of Ki-67-positive proliferating myofibroblasts in the infarcted myocardium in comparison with wildtype (WT) animals (Smad3−/− 917±291 cells/mm 2 vs. WT 614±115 cells/mm 2 , p<0.05). In vitro experiments suggested that TGF-β inhibits murine cardiac fibroblast proliferation in a concentration-dependent manner and that the antiproliferative effects of TGF-β are abrogated in Smad3 −/− fibroblasts. On the other hand Smad3 signaling was essential for extracellular matrix protein synthesis by cardiac fibroblasts. TGF-β-mediated induction of procollagen type III and of the matricellular protein tenascin-C in cardiac fibroblasts was dependent on Smad3. In addition, TGF-β-induced Tissue Inhibitor of Metalloproteinases (TIMP)-1 and -2 upregulation was also abrogated in Smad3 −/− fibroblasts, suggesting that Smad3 signaling regulates matrix metabolism. In vivo, Smad3 −/− infarcts exhibited attenuated tenascin-C and collagen deposition in the infarct and in the remodeling non-infarcted heart. Our findings suggest that the Smad3 pathway critically regulates fibroblast function in healing myocardial infarction. In Smad3 −/− mice, the healing infarct contains abundant myofibroblasts that exhibit enhanced proliferative activity, but have markedly decreased ability to synthesize extracellular matrix proteins and to produce TIMPs. In the absence of Smad3, attenuated matrix deposition in the remodeling non-infarcted heart results in decreased dilation and ameliorated diastolic dysfunction. This research has received full or partial funding support from the American Heart Association, AHA South Central Affiliate (Arkansas, New Mexico, Oklahoma & Texas).

p38 MAP kinase inhibitor reverses stress-induced cardiac myocyte dysfunction

2005 ◽  
Vol 98 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Hong Kan ◽  
Dale Birkle ◽  
Abnash C. Jain ◽  
Conard Failinger ◽  
Sherry Xie ◽  
...  
Keyword(s):  
Map Kinase ◽  
Cardiac Myocyte ◽  
Kinase Inhibitor ◽  
Ventricular Myocytes ◽  
Myocardial Dysfunction ◽  
P38 Map Kinase ◽  
Border Detection ◽  
Rat Ventricular Myocytes ◽  
Adult Rat ◽  
Fractional Shortening

Stress is gaining increasing acceptance as an independent risk factor contributing to adverse cardiovascular outcomes. Potential mechanisms responsible for the deleterious effects of stress on the development and progression of cardiovascular disease remain to be elucidated. An established animal model of stress in humans is the prenatally stressed (PS) rat. We stressed rats in their third trimester of pregnancy by daily injections of saline and moving from cage to cage. Male offspring of these stressed dams (PS) and age-matched male control offspring (control) were further subjected to restraint stress (R) at 6 and 7 wk of age. Echocardiography revealed a significant decrease in fractional shortening in PS + R vs. controls + R (45.8 ± 3.9 vs. 61.9 ± 2.4%, PS + R vs. controls + R; P < 0.01; n = 12). Isolated adult rat ventricular myocytes from PS + R also revealed diminished fractional shortening (6.7 ± 0.8 vs. 12.7 ± 1.1%, PS + R vs. controls + R; P < 0.01; n = 24) and blunted inotropic responses to isoproterenol ( P < 0.01; n = 24) determined by automated border detection. The p38 mitogen-activated protein (MAP) kinase inhibitor SB-203580 blocked p38 MAP kinase phosphorylation, reversed the depression in fractional shortening, and partially ameliorated the blunted adrenergic signaling seen in adult rat ventricular myocytes from PS + R. Phosphorylation of p38 MAP kinase in cardiac myocytes by stress may be sufficient to lead to myocardial dysfunction in animal models and possibly humans.

Coupling of M2 muscarinic receptors to ERK MAP kinases and caldesmon phosphorylation in colonic smooth muscle

2000 ◽  
Vol 278 (3) ◽  
pp. G429-G437 ◽  
Author(s):  
Amy K. Cook ◽  
Michael Carty ◽  
Cherie A. Singer ◽  
Ilia A. Yamboliev ◽  
William T. Gerthoffer
Keyword(s):  
Smooth Muscle ◽  
Map Kinase ◽  
Muscarinic Receptors ◽  
Map Kinases ◽  
Kinase Inhibitor ◽  
Receptor Activation ◽  
Inhibitory Effect ◽  
Subsequent Treatment ◽  
P38 Map Kinase

Coupling of M2 and M3 muscarinic receptors to activation of mitogen-activated protein (MAP) kinases and phosphorylation of caldesmon was studied in canine colonic smooth muscle strips in which M3 receptors were selectively inactivated by N, N-dimethyl-4-piperidinyl diphenylacetate (4-DAMP) mustard (40 nM). ACh elicited activation of extracellular signal-regulated kinase (ERK) 1, ERK2, and p38 MAP kinases in control muscles and increased phosphorylation of caldesmon (Ser789), a putative downstream target of MAP kinases. Alkylation of M3 receptors with 4-DAMP had only a modest inhibitory effect on ERK activation, p38 MAP kinase activation, and caldesmon phosphorylation. Subsequent treatment with 1 μM AF-DX 116 completely prevented activation of ERK and p38 MAP kinase and prevented caldesmon phosphorylation. Caldesmon phosphorylation was blocked by the MAP kinase/ERK kinase inhibitor PD-98509 but not by the p38 MAP kinase inhibitor SB-203580. These results indicate that colonic smooth muscle M2 receptors are coupled to ERK and p38 MAP kinases. Activation of ERK, but not p38 MAP kinases, results in phosphorylation of caldesmon in vivo, which is a novel function for M2receptor activation in smooth muscle.

Sign in / Sign up

Export Citation Format

Share Document