PHLDA1 is a new therapeutic target of oxidative stress and ischemia reperfusion-induced myocardial injury

Oxidative stress plays an important role in myocardial ischemia-reperfusion injury. Pleckstrin homology-like domain, family A, member 1 (PHLDA1) was first identified in apoptosis induced by T cell receptor activation, and was shown to play a different role in different cell types and under different stimuli. The role and mechanism of PHLDA1 in oxidative stress-induced cardiomyocyte injury and cardiac ischemia-reperfusion were therefore determined. Cell viability and apoptotic rate were measured by Cell Counting Kit-8 and flow cytometry, respectively. Mitochondrial membrane potential was measured using JC-1 test kit. Reactive oxygen species (ROS) production was detected using ROS kit. HE staining was used to detect histological morphology, 2,3,5-triphenyltetrazolium chloride staining to detect infarct size, terminal deoxynucleotidyl transferase dUTP nick end labeling staining to detect the apoptotic rate, and immunohistochemistry and western blot analysis to detect protein expression. The binding of PHLDA1 to Bcl-2 associated X (Bax) was detected by immunoprecipitation. The results indicated that PHLDA1 is highly expressed in oxidative stress-induced cardiomyocyte and myocardial ischemia-reperfusion injuries. PHLDA1 overexpression in cardiomyocytes promoted oxidative stress-induced cardiomyocyte injury. At the same time, PHLDA1 knockdown improved oxidative stress-induced cardiomyocyte and myocardial ischemia-reperfusion injuries. In addition, PHLDA1 binds to Bax and the interaction is enhanced under H2O2 stimulation. The present results indicated that PHLDA1 interacts with Bax to participate in oxidative stress-induced cardiomyocyte injury and myocardial ischemia reperfusion injury.