SB 203580, an inhibitor of p38 MAPK, abolishes infarct-limiting effect of ischemic preconditioning in isolated rabbit hearts

2000 â—½  
Vol 95 (6) â—½  
pp. 466-471 â—½  
Author(s):  
Atsushi Nakano â—½  
Michael V. Cohen â—½  
Stuart Critz â—½  
James M. Downey
Keyword(s):  
P38 Mapk â—½  
Ischemic Preconditioning â—½  
Sb 203580

The p38 MAPK/NF-κB Pathway Mediates GLT-1 Up-regulation during Cerebral Ischemic Preconditioning-induced Brain Ischemic Tolerance in Rats

2021 â—½  
Author(s):  
Ya-Wei Sun â—½  
Ling-Yan Zhang â—½  
Shu-Juan Gong â—½  
Yu-Yan Hu â—½  
Jing-Ge Zhang â—½  
...  
Keyword(s):  
P38 Mapk â—½  
Ischemic Preconditioning â—½  
Ischemic Tolerance â—½  
Cerebral Ischemic â—½  
Cerebral Ischemic Preconditioning

Modification of ischemia/reperfusion induced infarct size by ischemic preconditioning in hypertrophied hearts

2021 â—½  
Vol 99 (2) â—½  
pp. 218-223
Author(s):  
Mohamad Nusier â—½  
Mohammad Alqudah â—½  
Vijayan Elimban â—½  
Naranjan S. Dhalla
Keyword(s):  
Protein Kinase â—½  
Cardiac Hypertrophy â—½  
Infarct Size â—½  
P38 Mapk â—½  
Ischemic Preconditioning â—½  
Creatine Phosphokinase â—½  
Ischemia Reperfusion â—½  
Mitogen Activated Protein Kinase â—½  
Normal Heart â—½  
Mitogen Activated Protein

This study examined the effects of ischemic preconditioning (IP) on the ischemia/reperfusion (I/R) induced injury in normal and hypertrophied hearts. Cardiac hypertrophy in rabbits was induced by L-thyroxine (0.5 mg/kg/day for 16 days). Hearts with or without IP (3 cycles of 5 min ischemia and 10 min reperfusion) were subjected to I/R (60 min ischemia followed by 60 min reperfusion). IP reduced the I/R-induced infarct size from 68% to 24% and 57% to 33% in the normal and hypertrophied hearts, respectively. Leakage of creatine phosphokinase in the perfusate from the hypertrophied hearts due to I/R was markedly less than that form the normal hearts; IP prevented these changes. Although IP augmented the increase in phosphorylated p38-mitogen-activated protein kinase (p38-MAPK) content due to I/R, this effect was less in the hypertrophied than in the normal heart. These results suggest that reduced cardioprotection by IP of the I/R-induced injury in hypertrophied hearts may be due to reduced activation of p38-MAPK in comparison with normal hearts.

Acute adenosine preconditioning is mediated by p38 MAPK activation in discrete subcellular compartments

2005 â—½  
Vol 288 (3) â—½  
pp. H1359-H1366 â—½  
Author(s):  
Cherry Ballard-Croft â—½  
Gentian Kristo â—½  
Yukihiro Yoshimura â—½  
Easton Reid â—½  
Byron J. Keith â—½  
...  
Keyword(s):  
P38 Mapk â—½  
Adenosine Receptor â—½  
Ischemia Reperfusion â—½  
Mitochondrial Fraction â—½  
Control Group â—½  
Mapk Activation â—½  
Subcellular Compartments â—½  
Sb 203580

Although acute adenosine preconditioning (PC) is well established, the signaling pathways mediating this cardioprotection remain unclear. Because adenosine receptor agonists activate p38 MAPK and this kinase has been implicated in ischemic and pharmacological PC, the purpose of this study was to determine the role of p38 MAPK in acute adenosine receptor PC. The role of p38 MAPK activation in discrete subcellular compartments during ischemia-reperfusion was also determined. The following groups were used in an in vivo rat ischemia-reperfusion model: 1) control (10% DMSO iv), 2) the A1/A2a adenosine receptor AMP-579 (50 μg/kg iv), 3) AMP-579 + the A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 100 μg/kg iv), 4) AMP-579 + the p38 MAPK inhibitor SB-203580 (1 mg/kg iv), and 5) SB-203580 alone. p38 MAPK activation was measured by Western blot analysis in cytosolic, mitochondrial, membrane, and nuclear/myofilament fractions obtained from hearts at preischemic, ischemic, and reperfusion time points. A significant reduction in infarct size was observed with AMP-579 PC, an effect blocked by DPCPX or SB-203580 pretreatment. AMP-579 treatment was associated with a significant increase in p38 MAPK activation in the nuclear/myofilament fraction before ischemia, whereas no activation of this kinase occurred during ischemia or reperfusion. In contrast, p38 MAPK was activated in the mitochondrial fraction by ischemia and in the cytosolic, mitochondrial, and membrane fractions by reperfusion in the control group. SB-203580 blocked the AMP-579-induced increase in phosphorylation of the downstream p38 substrate activating transcription factor-2. These results suggest a role for p38 MAPK activation in discrete subcellular compartments in acute adenosine A1 receptor PC.

Role of F-actin organization in p38 MAP kinase-mediated apoptosis and necrosis in neonatal rat cardiomyocytes subjected to simulated ischemia and reoxygenation

2005 â—½  
Vol 289 (6) â—½  
pp. H2310-H2318 â—½  
Author(s):  
Takayuki Okada â—½  
Hajime Otani â—½  
Yue Wu â—½  
Shiori Kyoi â—½  
Chiharu Enoki â—½  
...  
Keyword(s):  
Cytochrome C â—½  
Map Kinase â—½  
Dna Fragmentation â—½  
P38 Mapk â—½  
Caspase 3 â—½  
Neonatal Rat â—½  
Cytochrome C Release â—½  
Actin Reorganization â—½  
Ldh Release â—½  
Sb 203580

Activation of p38 mitogen-activated protein (MAP) kinase (MAPK) has been implicated in the mechanism of cardiomyocyte (CMC) protection and injury. The p38 MAPK controversy may be related to differential effects of this kinase on apoptosis and necrosis. We have hypothesized that p38 MAPK-mediated F-actin reorganization promotes apoptotic cell death, whereas it protects from osmotic stress-induced necrotic cell death. Cultured neonatal rat CMCs were subjected to 2 h of simulated ischemia followed by reoxygenation. p38 MAPK activity measured by phosphorylation of MAP kinase-activated protein (MAPKAP) kinase 2 was increased during simulated ischemia and reoxygenation. This was associated with translocation of heat shock protein 27 (HSP27) from the cytosolic to the cytoskeletal fraction and F-actin reorganization. Cytochrome c release from mitochondria, caspase-3 activation, and DNA fragmentation were increased during reoxygenation. Robust lactate dehydrogenase (LDH) release was observed under hyposmotic (140 mosM) reoxygenation. The p38 MAPK inhibitor SB-203580 abrogated activation of p38 MAPK, translocation of HSP27, and F-actin reorganization and prevented cytochrome c release, caspase-3 activation, and DNA fragmentation. Conversely, SB-203580 enhanced LDH release during hyposmotic reoxygenation. The F-actin disrupting agent cytochalasin D inhibited F-actin reorganization and prevented cytochrome c release, caspase-3 activation, and DNA fragmentation, whereas it enhanced LDH release during hyposmotic reoxygenation. When CMCs were incubated under the isosmotic condition for the first 15 min of reoxygenation, SB-203580 and cytochalasin D increased ATP content of CMCs and prevented LDH release after the conversion to the hyposmotic condition. These results suggest that F-actin reorganization mediated by activation of p38 MAPK plays a differential role in apoptosis and protection against osmotic stress-induced necrosis during reoxygenation in neonatal rat CMCs; however, the sarcolemmal fragility caused by p38 MAPK inhibition can be reversed during temporary blockade of physical stress during reoxygenation.

Acute p38 MAPK activation decreases force development in ventricular myocytes

2003 â—½  
Vol 285 (6) â—½  
pp. H2578-H2586 â—½  
Author(s):  
Yi Chen â—½  
Ravi Rajashree â—½  
Qinghang Liu â—½  
Polly Hofmann
Keyword(s):  
Protein Kinase â—½  
P38 Mapk â—½  
Ventricular Myocytes â—½  
Fold Increase â—½  
Isometric Tension â—½  
Mitogen Activated Protein Kinase â—½  
Independent Manner â—½  
Mapk Activation â—½  
Force Development â—½  
Sb 203580

Evidence suggests that p38 mitogen-activated protein kinase (MAPK) activation influences cardiac function on an acute basis. The characterization and mechanisms by which this occurs were investigated in the present study. Adult rat ventricular myocytes treated with 1 mM arsenite for 30 min had a 16-fold increase in p38 MAPK phosphorylation that was attenuated by SB-203580 (a p38 MAPK inhibitor). Extracellular signal-regulated protein kinase (ERK) and c-Jun NH2-terminal kinase (JNK) were also minimally activated, but this activation was not sensitive to SB-203580. In addition, arsenite caused a p38 MAPK-independent translocation/activation of protein phosphatase 2a (PP2a) and decrease in phosphorylation of myosin light chain 2 (LC2). Arsenite-p38 MAPK activation led to translocation of heat shock protein 27 but not αB-crystallin to the myofilaments. Using isolated cardiomyocytes, we determined that arsenite reduces isometric tension without a change in Ca2+ sensitivity of tension via p38 MAPK and lowers myofibrillar actomyosin Mg2+-ATPase activity in a p38 MAPK-independent manner. Thus arsenite induces a p38 MAPK-independent change in PP2a and LC2 that may account for the arsenite-dependent decrease in ATPase and a p38 MAPK-dependent modification of the myofilaments that decreases myocardial force development.

TLR5-mediated activation of p38 MAPK regulates epithelial IL-8 expression via posttranscriptional mechanism

2003 â—½  
Vol 285 (2) â—½  
pp. G282-G290 â—½  
Author(s):  
Yimin Yu â—½  
Hui Zeng â—½  
Sean Lyons â—½  
Adam Carlson â—½  
Didier Merlin â—½  
...  
Keyword(s):  
P38 Mapk â—½  
Mrna Stability â—½  
Mrna Translation â—½  
Mrna Levels â—½  
Dependent Manner â—½  
Maximal Inhibition â—½  
Mapk Activation â—½  
Intestinal Epithelia â—½  
Tnf Α â—½  
Sb 203580

Toll-like receptors (TLRs) activate antimicrobial gene expression in response to detection of specific bacterial products. Relatively little is known about TLR5, the only TLR thought to be preferentially expressed by epithelial cells, beyond that it confers activation of the transcription factor NF-κB in a MyD-88 dependent manner in response to flagellin. Because TLRs, in general, are also thought to signal through members of the MAPK family, we examined flagellin-induced MAPK activation (via examining its phosphorylation status) and its subsequent role in expression of the chemokine IL-8 in polarized intestinal epithelia. Flagellin, like other proinflammatory stimuli (TNF-α, Salmonella typhimurium), activated p38 MAPK in a TLR5-dependent manner, whereas aflagellate bacteria or EGF did not activate this kinase. Although ERK1 and -2 were also observed to be activated in response to flagellin, their activation was not restricted to proinflammatory stimuli because they were also potently activated by aflagellate bacteria ( S. typhimurium or Escherichia coli) and EGF (neither of which activate NF-κB in these cells). Pharmacological inhibition of p38 MAPK (by SB-203580) potently (IC50 = 10 nM) reduced expression of IL-8 protein (maximal inhibition, 75%) but had no effect on NF-κB activation, only slightly attenuated upregulation of IL-8 mRNA levels in response to flagellin, and did not effect IL-8 mRNA stability. Together, these results indicate that epithelial TLR5 mediates p38 activation and subsequently regulates flagellin-induced IL-8 expression independently of NF-κB, probably by influencing IL-8 mRNA translation.

p38 MAPK and NF-κB mediate COX-2 expression in human airway myocytes

2003 â—½  
Vol 285 (5) â—½  
pp. L1087-L1098 â—½  
Author(s):  
Cherie A. Singer â—½  
Kimberly J. Baker â—½  
Alan McCaffrey â—½  
David P. AuCoin â—½  
Melissa A. Dechert â—½  
...  
Keyword(s):  
P38 Mapk â—½  
Binding Activity â—½  
Dependent Manner â—½  
Human Airway â—½  
Mitogen Activated Protein â—½  
Steady State Levels â—½  
Cox 2 â—½  
P38 Mapk Inhibitor â—½  
Factor Α â—½  
Sb 203580

We have previously demonstrated that p38 and extracellular signal-regulated protein kinase (ERK) mitogen-activated protein kinases (MAPK) are components of proinflammatory induced cytokine expression in human airway myocytes. The experiments described here further these studies by examining p38 MAPK and NF-κB regulation of cyclooxygenase-2 (COX-2) expression in response to a complex inflammatory stimulus consisting of 10 ng/ml interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and interferon (IFN)-γ. COX-2 expression was induced with this stimulus in a time-dependent manner, with maximal expression seen 12-20 h after treatment. Semiquantitative RT-PCR and immunoblotting experiments demonstrate decreased COX-2 expression following treatment with the p38 MAPK inhibitor SB-203580 (25 μM) or the proteosome inhibitor MG-132 (1 μM). SB-203580 did not affect cytokine-stimulated IκBα degradation, NF-κB nuclear binding activity, or NF-κB-dependent signaling from the COX-2 promoter, indicating that p38 MAPK and NF-κB may affect COX-2 expression via separate signaling pathways. SB-203580, but not MG-132, also increased the initial rate of COX-2 mRNA decay, indicating p38 MAPK, but not NF-κB, participates in the regulation of COX-2 mRNA stability. These findings suggest that although p38 MAPK and NF-κB signaling regulate steady-state levels of COX-2 expression, p38 MAPK additionally affects stability of COX-2 mRNA in cytokine-stimulated human airway myocytes.

Menadione mimics the infarct-limiting effect of preconditioning in isolated rat hearts

2001 â—½  
Vol 281 (2) â—½  
pp. H590-H595 â—½  
Author(s):  
Yuankun Yue â—½  
Maike Krenz â—½  
Michael V. Cohen â—½  
James M. Downey â—½  
Stuart D. Critz
Keyword(s):  
Free Radicals â—½  
Infarct Size â—½  
P38 Mapk â—½  
Ischemic Preconditioning â—½  
Free Radical Scavenger â—½  
Mitogen Activated Protein Kinase â—½  
Radical Scavenger â—½  
Risk Zone â—½  
Regional Ischemia â—½  
Rat Hearts

The role of mitochondrial free radicals in the cardioprotective effect of ischemic preconditioning was examined in isolated buffer-perfused rat hearts. Infarct size in control rat hearts subjected to 30 min of regional ischemia and 120 min of reperfusion was 32.6 ± 3.4% of the risk zone. Ischemic preconditioning (3 cycles of 5-min global ischemia/5-min reperfusion) before the same regional ischemia and reperfusion protocol significantly reduced infarct size to 2.6 ± 0.8% of the risk zone. Perfusion with menadione (3.0 μM), a generator of mitochondrial free radicals, in lieu of preconditioning ischemia significantly reduced infarction to 10.9 ± 2.7%. N-2-mercaptopropionylglycine (1.0 mM), a free radical scavenger, blocked the protection of menadione, significantly increasing infarction to 23.5 ± 1.1%. Myxothiazol (0.6 μM), a site III mitochondrial inhibitor, blocked the protection of menadione and significantly increased infarction to 25.2 ± 3.8%. The infarct-limiting effect of menadione was attenuated to 19.7 ± 1.5% of the risk zone by 10 μM SB203580, a p38 mitogen-activated protein kinase (MAPK) inhibitor. Furthermore, menadione significantly increased p38 MAPK phosphorylation to a level 5.6-fold over basal. These results indicate that free radicals that originate within mitochondria can activate p38 MAPK and protect hearts against infarction.

IL-1β signaling in cat lower esophageal sphincter circular muscle

2006 â—½  
Vol 291 (4) â—½  
pp. G672-G680 â—½  
Author(s):  
Weibiao Cao â—½  
Ling Cheng â—½  
Jose Behar â—½  
Piero Biancani â—½  
Karen M. Harnett
Keyword(s):  
Lower Esophageal Sphincter â—½  
P38 Mapk â—½  
Circular Muscle â—½  
Circular Smooth Muscle â—½  
Sequential Activation â—½  
Cox 2 â—½  
Esophageal Sphincter â—½  
Sb 203580

In a cat model of acute experimental esophagitis, resting in vivo lower esophageal sphincter (LES) pressure and in vitro tone are lower than in normal LES, and the LES circular smooth muscle layer contains elevated levels of IL-1β that decrease the LES tone of normal cats. We now examined the mechanisms of IL-1β-induced reduction in LES tone. IL-1β significantly reduced acetylcholine-induced Ca2+ release in Ca2+-free medium, and this effect was partially reversed by catalase, demonstrating a role of H2O2 in these changes. IL-1β significantly increased the production of H2O2, and the increase was blocked by the p38 MAPK inhibitor SB-203580, by the cytosolic phospholipase A2 (cPLA2) inhibitor AACOCF3, and by the NADPH oxidase inhibitor apocynin, but not by the MEK1 inhibitor PD-98059. IL-1β significantly increased the phosphorylation of p38 MAPK and cPLA2. IL-1β-induced cPLA2 phosphorylation was blocked by SB-203580 but not by AACOCF3, suggesting sequential activation of p38 MAPK-phosphorylating cPLA2. The IL-1β-induced reduction in LES tone was partially reversed by AACOCF3 and by the Ca2+-insensitive PLA2 inhibitor bromoenol lactone (BEL). IL-1β significantly increased cyclooxygenase (COX)-2 and PGE2 levels. The increase in PGE2 was blocked by SB-203580, AACOCF3, BEL, and the COX-2 inhibitor NS-398 but not by PD-98059 or the COX-1 inhibitor valeryl salicylate. The data suggested that IL-1β reduces LES tone by producing H2O2, which may affect Ca2+-release mechanisms and increase the synthesis of COX-2 and PGE2. Both H2O2 and PGE2 production depend on sequential activation of p38 MAPK and cPLA2. cPLA2 activates NADPH oxidases, producing H2O2, and may produce arachidonic acid, converted to PGE2 via COX-2.

p38 mitogen-activated protein kinase inhibits calcium-dependent chloride secretion in T84 colonic epithelial cells

AJP Cell Physiology â—½  
2003 â—½  
Vol 284 (2) â—½  
pp. C339-C348 â—½  
Author(s):  
Stephen J. Keely â—½  
Kim E. Barrett
Keyword(s):  
Protein Kinase â—½  
Epithelial Cells â—½  
Signaling Pathway â—½  
P38 Mapk â—½  
Mitogen Activated Protein Kinase â—½  
Muscarinic Agonist â—½  
Colonic Epithelial Cells â—½  
Mitogen Activated Protein â—½  
Intracellular Ca â—½  
Sb 203580

We have previously shown that Ca2+-dependent Cl−secretion across intestinal epithelial cells is limited by a signaling pathway involving transactivation of the epidermal growth factor receptor (EGFR) and activation of ERK mitogen-activated protein kinase (MAPK). Here, we have investigated a possible role for p38 MAPK in regulation of Ca2+-dependent Cl− secretion. Western blot analysis of T84 colonic epithelial cells revealed that the muscarinic agonist carbachol (CCh; 100 μM) stimulated phosphorylation and activation of p38 MAPK. The p38 inhibitor SB-203580 (10 μM) potentiated and prolonged short-circuit current ( I sc) responses to CCh across voltage-clamped T84 cells to 157.4 ± 6.9% of those in control cells ( n = 21; P < 0.001). CCh-induced p38 phosphorylation was attenuated by the EGFR inhibitor tyrphostin AG-1478 (0.1 nM–10 μM) and by the Src family kinase inhibitor PP2 (20 nM–2 μM). The effects of CCh on p38 phosphorylation were mimicked by thapsigargin (TG; 2 μM), which specifically elevates intracellular Ca2+, and were abolished by the Ca2+ chelator BAPTA-AM (20 μM), implying a role for intracellular Ca2+ in mediating p38 activation. SB-203580 (10 μM) potentiated I sc responses to TG to 172.4 ± 18.1% of those in control cells ( n= 18; P < 0.001). When cells were pretreated with SB-203580 and PD-98059 to simultaneously inhibit p38 and ERK MAPKs, respectively, I sc responses to TG and CCh were significantly greater than those observed with either inhibitor alone. We conclude that Ca2+-dependent agonists stimulate p38 MAPK in T84 cells by a mechanism involving intracellular Ca2+, Src family kinases, and the EGFR. CCh-stimulated p38 activation constitutes a similar, but distinct and complementary, antisecretory signaling pathway to that of ERK MAPK.

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