H2S preconditioning-induced PKC activation regulates intracellular calcium handling in rat cardiomyocytes.
The present study was aimed to investigate the regulatory effect of protein kinase C (PKC) on intracellular Ca(2+) handling in hydrogen sulfide (H(2)S)-preconditioned cardiomyocytes and its consequent effects on ischemia challenge. Immunoblot analysis was used to assess PKC isoform translocation in the rat cardiomyocytes 20 h after NaHS (an H(2)S donor, 10(-4) M) preconditioning (SP, 30 min). Intracellular Ca(2+) was measured with a spectrofluorometric method using fura-2 ratio as an indicator. Cell length was compared before and after ischemia-reperfusion insults to indicate the extent of hypercontracture. SP motivated translocation of PKCalpha, PKCepsilon, and PKCdelta to membrane fraction but only translocation of PKCepsilon and PKCdelta was abolished by an ATP-sensitive potassium channel blocker glibenclamide. It was also found that SP significantly accelerated the decay of both electrically and caffeine-induced intracellular [Ca(2+)] transients, which were reversed by a selective PKC inhibitor chelerythrine. These data suggest that SP facilitated Ca(2+) removal via both accelerating uptake of Ca(2+) into sarcoplasmic reticulum and enhancing Ca(2+) extrusion through Na(+)/Ca(2+) exchanger in a PKC-dependent manner. Furthermore, blockade of PKC also attenuated the protective effects of SP against Ca(2+) overload during ischemia and against myocyte hypercontracture at the onset of reperfusion. We demonstrate for the first time that SP activates PKCalpha, PKCepsilon, and PKCdelta in cardiomyocytes via different signaling mechanisms. Such PKC activation, in turn, protects the heart against ischemia-reperfusion insults at least partly by ameliorating intracellular Ca(2+) handling.
Pan
Ting-Ting
TT
Cardiovascular Biology Research Group, Department of Pharmacology, National University of Singapore, Singapore.
Neo
Kay Li
KL
Hu
Li-Fang
LF
Yong
Qian Chen
QC
Bian
Jin-Song
JS
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D053119:Benzophenanthridines / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004558:Electric Stimulation; D004789:Enzyme Activation; D005905:Glyburide / Q000494:pharmacology; D054086:KATP Channels / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051571:Protein Kinase C-alpha / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000378:metabolism; D051744:Protein Kinase C-epsilon / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D051381:Rats; D017207:Rats, Sprague-Dawley; D012107:Research Design; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D019831:Sodium-Calcium Exchanger / Q000378:metabolism; D013440:Sulfides / Q000494:pharmacology*; D013997:Time Factors
D000470:Alkaloids; D053119:Benzophenanthridines; D054086:KATP Channels; D026902:Potassium Channel Blockers; D047428:Protein Kinase Inhibitors; D019831:Sodium-Calcium Exchanger; D013440:Sulfides; D002110:Caffeine; C016299:chelerythrine; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; C025451:sodium bisulfide; D005905:Glyburide; D002118:Calcium