Knock-down of farnesyl pyrophosphate synthase protects heart-derived H9c2 cells against hypoxia/reoxygenation-induced injury

Farnesyl pyrophosphate synthase (FPPS) is a key enzyme in the mevalonate pathway. Our previous studies have indicated that cardiac-specific overexpression of FPPS induces cardiac hypertrophy and dysfunction in mice, and inhibition of FPPS prevents angiotensin (Ang) II-induced hypertrophy in cardiomyocytes. However, the role for FPPS in myocardial ischemia/reperfusion (MIR) injury is still not clear. The objective of this work was to investigate the effect of FPPS on MIR injury in H9c2 cells which were subjected to hypoxia/reoxygenation (HR) to mimic MIR. Prior to HR, cells were transfected with pE-mFPPS, shFPPS, or pE-GFP. Our results showed that the overexpression of FPPS reduced cell proliferation, increased cell injury and cell apoptosis, and knock-down of FPPS improved cell proliferation, decreased cell injury, and cell apoptosis after HR. Besides, overexpression of FPPS increased Rac1 activity and reactive oxygen species (ROS) generation, while FPPS silencing decreased Rac1 activity and ROS generation. Based on these findings, we propose that knock-down of FPPS reduces Rac1 activity and ROS production, and finally leads to the decrease of HR-induced injury in H9c2 cells. These findings point that FPPS might be a potential target in preventing H9c2 cells from HR-induced injury.