N-acetylcysteine blocked hypoxia-reoxygenation induced apoptosis through ROS-p38 MAPK signaling pathway in neonatal rat cardiomyocytes

Objective Previous investigations have shown that N-acetylcysteine (NAC) could regulate diverse cell type’s apoptosis. The purpose of this study was to evaluate the mechanism of NAC reversed apoptosis of cardiomyocytes induced by hypoxia-reoxygenation (H/R). Methods Cardiomyocytes were treated with hypoxia 6 h and reoxygenation 72 h in the absence and presence of NAC (100μmol/L). The ROS was assayed by using Image-iTTM LIVE green reactive oxygen species detection kit. The viability of cell was assayed with trypan blue. Early stages of apoptosis were assessed by flow cytometry using Annexin V, and late stages of apoptosis were assessed using TUNEL system. Bcl2 and bax mRNA levels were determined by real-time quantitative PCR. Bcl2, bax, p38 and pp38 protein levels were determined by western blot. Results We found that H/R could markedly increase ROS generation and induce the apoptosis of cardiomyocytes (P<0.01). NAC (100μmol/L) significantly reduced the generation of ROS and apoptosis (P all <0.01). NAC also significantly reduced the protein ratio of pp38 and p38 and increased the RNA and protein ratio of bcl2 and bax (P all <0.01). Conclusion The results showed that NAC significantly reduced apoptosis through inhibiting the phosphorylation of p38 signal pathway, which has potential value for clinical cardiac diseases