TY - JOUR
T1 - Acute adenosine preconditioning is mediated by p38 MAPK activation in discrete subcellular compartments
AU - Ballard-Croft, Cherry
AU - Kristo, Gentian
AU - Yoshimura, Yukihiro
AU - Reid, Easton
AU - Keith, Byron J.
AU - Mentzer, Robert M.
AU - Lasley, Robert D.
PY - 2005/3
Y1 - 2005/3
N2 - 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 A 1/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.
AB - 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 A 1/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.
KW - A receptor
KW - Compartmentation
KW - In vivo rat model
KW - Ischemia-reperfusion
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U2 - 10.1152/ajpheart.01006.2004
DO - 10.1152/ajpheart.01006.2004
M3 - Article
C2 - 15539417
AN - SCOPUS:13944277694
SN - 0363-6135
VL - 288
SP - H1359-H1366
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 3 57-3
ER -