Downregulation of Circ-ZNF609 Reduces PM2.5-Induced Cardiomyocyte Injury Associated with Reduced YTHDF3 Expression

Cardiac injury resulting from exposure to fine particulate matter with aerodynamic diameter ≤2.5 μm (PM 2.5 ) has been observed. Circular RNAs (circRNAs) play diverse roles in cardiac pathophysiology. Circ-ZNF609 has been reported to play important roles in doxorubicin-induced cardiotoxicity and myocardial ischemia-reperfusion injury. However, its role in PM 2.5 -induced myocardial injury remains unknown. In our research, we reported that down-regulation of circ-ZNF609 significantly reduced PM 2.5 -induced cardiomyocytes apoptosis as evidenced by decreased TUNEL positive cardiomyocytes, Bax/Bcl-2, and cleaved caspase-3/caspase-3 ratio, and increased cell viability as determined by CCK8. Interestingly, down-regulation of circ-ZNF609 inhibited the expression of YTHDF3. Moreover, YTHDF3 knockdown can rescue the aggravating effects of circ-ZNF609 overexpression on PM 2.5 -induced cardiomyocytes injury via reducing cardiomyocytes apoptosis and promoting cell viability. Circ-ZNF609 knockdown may alleviate PM 2.5 -induced cardiomyocyte injury, at least partially, by regulating YTHDF3 expression and mRNA stability. These findings provide preliminary evidence supporting the involvement of circ-ZNF609 in PM 2.5 -induced cardiomyocyte injury and warrant further investigation in vivo .