FrzA gene protects cardiomyocytes from H2O2-induced oxidative stress through restraining the Wnt/Frizzled pathway.

Background: Lately, there is accumulating evidence that the Wnt/Frizzled pathway is reactivated after myocardial infarction, the inhibition of the pathway is beneficial since it reduce of myocardial apoptosis and prevents heart failure. FrzA/Sfrp-1, a secreted frizzled-related protein and antagonist for the wnt/frizzled pathway. We assessed the hypothesis that FrzA protects cardiomyocytes from H2O2-Induced Oxidative damage through the inhibition of Wnt/Frizzled pathway activity.

Methods: We used a recombinant AAV9 vector to deliver FrzA gene into neonatal rat ventricle myocytes and developed an oxidative stress model using H2O2. The cell vitality was measured by MTT colorimetric assay. Western blot and RT-PCR were used to evaluate the expressions of Dvl-1, β-catenin, c-Myc, Bax and Bcl-2. Flow cytometry analysis of cardiomyocytes apoptosis.

Results: We confirmed that Wnt/frizzled pathway is involved in H2O2-induced apoptosis in cardiomyocytes. Compared with controls, H2O2 induced the upregulation of Dvl-1, β-catenin, and c-Myc. FrzA suppressed the expression of Dvl-1, β-catenin, c-Myc and the activity of the Wnt/frizzled pathway. Furthermore, FrzA over-expression decreased the apoptotic rate, and the Bax/Bcl-2 ratio in cardiomyocytes treated with H2O2.

Conclusions: FrzA, through the inhibition of Wnt/Frizzled pathway activity reduced H2O2-induced cardiomyocytes apoptosis and could be a potential therapeutic target for prevention of cardiac oxidative damage.