KR-32570, a novel Na+/H+ exchanger-1 inhibitor, attenuates hypoxia-induced cell death through inhibition of intracellular Ca2+ overload and mitochondrial death pathway in H9c2 cells.
A novel Na+/H+ exchanger-1 (NHE-1) inhibitor [5-(2-methoxy-5-chloro-5-phenyl)furan-2-ylcarbonyl]guanidine (KR-32570) has been previously demonstrated to elicit cardioprotective effect against ischemic injury in rat heart. In the present study, we examined the effects of KR-32570 on cell death induced by hypoxic insult in heart-derived H9c2 cells. Treatment with KR-32570 (1-10 microM) significantly reduced hypoxia-induced necrotic cell death (lactate dehydrogenase release) and apoptotic cell death (TUNEL-positivity, caspase-3 activity). KR-32570 also decreased the cytosolic and mitochondrial Ca2+ overload induced by hypoxia. Inhibition of mitochondrial Ca2+ overload by ruthenium red mimicked the anti-apoptotic effect of KR-32570. In addition, KR-32570 significantly recovered the large reduction in mitochondrial membrane potential (delta psi(m)) and cytochrome c release induced by hypoxia. Taken together, our results suggest that a new NHE-1 inhibitor KR-32570 elicits potent cardioprotective effects in H9c2 cells, and its effects may be mediated by inhibition of intracellular Ca2+ overload and mitochondrial death pathway during hypoxia.
Kim
Mi Jeong
MJ
Department of Physiology, Ajou University School of Medicine, #5 Woncheon-dong, Suwon 442-749, South Korea.
Moon
Chang-Hyun
CH
Kim
Mi-Young
MY
Lee
Sunkyung
S
Yi
Kyu Yang
KY
Yoo
Sung Eun
SE
Lee
Soo Hwan
SH
Baik
Eun Joo
EJ
Jung
Yi-Sook
YS
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002316:Cardiotonic Agents / Q000494:pharmacology*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects*; D002460:Cell Line; D006146:Guanidines / Q000494:pharmacology*; D000860:Hypoxia; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D051381:Rats; D017923:Sodium-Hydrogen Exchangers / Q000037:antagonists & inhibitors
D002316:Cardiotonic Agents; D006146:Guanidines; D017923:Sodium-Hydrogen Exchangers; C069139:growth factor-activatable Na-H exchanger NHE-1; C502305:(5-(2-methoxy-5-chloro-5-phenyl)furan-2-ylcarbonyl)guanidine; D007770:L-Lactate Dehydrogenase; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D002118:Calcium