Ozone protects cardiomyocytes against ischemia/reperfusion injury: Regulating the heat shock protein 70 (HPS70) expression through activating the JAK2/STAT3 Pathway

Ischemia/reperfusion (I/R) injury causes complications in early coronary artery reperfusion for acute myocardial infarction (AMI). Ozone (O-3) has been reported to be applied for protecting I/R injury, but its detailed mechanism remains unclear. Our study focused on the protective effect of O-3 pretreatment on myocardial I/R injury and JAK2/STAT3 signaling and HSP70 regulation involving in the mediation. The rat hearts which were perfused and isolated as well as the cultured cardiomyocytes of neonatal rat were exposed to hypoxia/reoxygenation (H/R) and different concentrations of O-3 followed by heat shock protein 70 (HSP70) siRNA treatment. The results showed O-3 attenuated the suppression of cell viability induced by H/R and decreased the release of activity of creatine kinase (CK), lactate dehydrogenase (LDH) and apoptosis of cardiomyocytes in vitro. Moreover, O-3 also activated the JAK2/STAT3 signaling, upregulated the expression of HSP70 both in vitro and vivo, and decreased the index of apoptosis of cardiomyocytes caused by I/R as well as myocardial infarct area in vivo. In addition, HSP70 siRNA and JAK2 inhibitor AG490 inhibited the cardioprotective effect of O-3. And the expression of HSP70 increased by ozone was reduced by AG-490. In conclusion, our results demonstrated that ozone protects cardiomyocytes in I/R injury through regulation of the expression of HSP70 by activating the JAK2/STAT3 pathway.

Automated summary

Ozone can protect cardiomyocytes from I/R injury by activating the JAK2/STAT3 pathway and upregulating the expression of HSP70, reducing cell apoptosis and myocardial infarct area.