Hydrogen Sulfide Protects Cardiomyocytes from Myocardial Ischemia-Reperfusion Injury by Enhancing Phosphorylation of Apoptosis Repressor with Caspase Recruitment Domain

Abstract

Hydrogen sulfide (H 2 S) displays an anti-apoptotic activity against myocardial ischemia reperfusion (MIR). Apoptosis repressor with caspase recruitment domain (ARC) is constitutively expressed in the heart and inhibits cell apoptosis when it is phosphorylated. Here, we investigated whether H 2 S could inhibit apoptosis by affecting ARC phosphorylation using cultured rat cardiomyocytes and a rat model of MIR. Primary cardiomyocytes were prepared from hearts of newborn rats and were pre-incubated with NaHS, a donor of H 2 S, for 60 min. Cardiomyocytes were subjected to hypoxia for 4 h, followed by reoxygenation for 2 h. The hypoxia and subsequent reoxygenation (H/R) significantly induced cell apoptosis, increased expression levels of Fas and FasL proteins, enhanced release of cytochrome c from mitochondria, and elevated caspase-3 activity, while H/R reduced ARC phosphorylation and increased the activity of calcineurin that dephosphorylates ARC. Pre-incubation with NaHS significantly attenuated the above effects through promoting ARC phosphorylation by reducing calcineurin activity and by increasing the activity of protein kinase casein kinase II (CK2) that phosphorylates ARC. In fact, TBB, a specific inhibitor of CK2, abolished the effects of NaHS. In rats undergoing MIR, NaHS significantly reduced the myocardial infarct size, cell apoptosis, calcineurin activity, and the expression levels of Fas, FasL and cleaved caspase-3 proteins, while NaHS increased ARC phosphorylation. In contrast, DL-propargylglycine, an inhibitor of cystathionine γ-lyase, the main enzyme for H 2 S production in hearts, showed opposite effects to NaHS. The results indicate that H 2 S inhibits apoptosis of cardiomyocytes induced by MIR through enhancing ARC phosphorylation.

The role of gasotransmitters NO, H2S and CO in myocardial ischaemia/reperfusion injury and cardioprotection by preconditioning, postconditioning and remote conditioning

“…H2S reduced calcineurin activity and the expression levels of Fas, FasL and cleaved caspase-3 proteins (Yao et al, 2012). More specifically, during the early PC period, H2S increased the nuclear localization of Nrf2, a transcription factor that regulates the gene expression of a number of antioxidants and increased the phosphorylation of PKCε and STAT-3.…”

“…NaHS administration before sustained ischaemia resulted in a remarkable reduction of the infarct size (Zhuo et al, 2009) and significantly reduced cell apoptosis (Sivarajah et al, 2009;Yao et al, 2012). Furthermore, a single bolus of NaHS administered 24 h before myocardial infarction produced a strong infarct-limiting effect and a time-course study demonstrated that the protection lasted for at least 3 days after the PC stimulus (Pan et al, 2009).…”

“…In contrast, PRG showed opposite effects to NaHS (Yao et al, 2012). PRG administration for 1 week and 2 days after I/R abolished the decrease of infarct size, compared with the group treated with NaHS, whereas a marked reduction of the infarct size and up-regulation of survivin was observed in the group treated with NaHS (Zhuo et al, 2009).…”

“…Reduced expression levels of Fas, FasL and cleaved caspase-3 proteins Yao et al (2012) In vivo (rats) PRG increased I/R Up-regulation of survivin Zhuo et al (2009) In vivo (mice overexpressing CSE in heart) Reduction of reperfusion injury Partial inhibition of mitochondrial respiration Elrod et al (2007) of natural origin, some synthetic H2S-releasing agents described. Among them, the phosphinodithioate derivative GYY4137 (morpholin-4-ium 4-methoxyphenyl-morpholinophosphinodithioate) represents an attractive example (Li et al, 2008).…”

“…H2S increases the open probability of KATP in cardiac myocytes Zhang et al (2007) Isolated hearts NaHS-PostC Reduction of infarct size Activation of the JAK2/STAT3 signalling pathway Luan et al (2012) Isolated hearts NaHS PostC Reduction of infarct size Activation of AKT, PKC, eNOS Yong et al (2008) In vivo (mice) NaHS PC Reduction of infarct size, decrease of troponin-I Decrease of oxidative stress, increase Nfr2, PKCε, STAT-3, HO-1, Trx1, HSP90, HSP70, Bcl-2, Bcl-xL, COX-2 and decrease of Bad Calvert et al (2009) In vivo (rats) NaHS PC Reduction of infarct size Up-regulation of survivin Zhuo et al (2009) In vivo (rats) NaHS PC Reduction of infarct size Reduction of calcineurin, Fas, Fas-L, caspase-3 and increase of ARC Yao et al (2012) In vivo (rats) NaHS PC Reduction of infarct size PKC-dependent mechanism Pan et al (2009) In vivo (rats) NaHS PC Reduction of infarct size Decrease in caspase-9, increase of Bcl-2, mitoKATP opening and increased phosphorylation of p38 Sivarajah et al (2009) In vivo rats S-allylcysteine (SAC) PC Reduction of infarct size SAC up-regulated CSE expression Chuah et al (2007) In vivo (pigs) Na2S PC Reduction of infarct size Lower lactate, improvement in noradrenaline response. No change in oxidative stress.…”