Abstract 12581: The N6-Methyladenosine Methylase Wtap is Essential for Cardiac Homeostasis

• Published in: Circulation (New York, N.Y.) N.Y.), 2022-11, Vol.146 (Suppl_1), p.A12581-A12581
• Main Authors: Han, Ziqiang, Zou, Yubao, Li, Shuai, Lu, Minjie, Nie, Yu, song, lei, Wang, Jizheng
• Format: Article
• Language: English
• ISSN: 0009-7322
• DOI: 10.1161/circ.146.suppl_1.12581

IntroductionN6-methyladenosine (m6A) methylation is one of the most common internal modifications in mammalian mRNA, and WTAP is a critical regulatory subunit of the RNA N6-methyladenosine methyltransferase complex. However, the roles of WTAP in cardiac structure and function are rarely known. Methods and ResultsWe found that the levels of m6A RNA methylation and the expression of WTAP were both decreased in myocardial tissue of the patients with hypertrophic cardiomyopathy, as well as in pressure overload-induced cardiac hypertrophy in mice. To determine the regulatory roles of WTAP, a conditional cardiac-specific knockout mice of WTAP was generated through Tamoxifen-inducible αMHC-Cre/loxP system. Depletion of WTPA resulted in heart failure in five days after Tamoxifen treatment, shown by enlarged heart and decreased left ventricular ejection fraction. Furthermore, we found WTAP knockout aggravated the progress of pathogenic cardiac remodeling induced by pressure overload, and abrogated the compensated response cardiac hypertrophy to hypertrophic stimulation. We found MYLK4 was a direct target of WTAP through a methylated RNA immunoprecipitation (MeRIP) sequencing, and it was validated by MeRIP-qPCR, RT-qPCR and RIP-qPCR. RNA stability analysis and dual-luciferase assays showed that depression of WTAP decreased m6A level of MYLK4 mRNA and resulted in a down-regulation of MYLK4 by reducing its RNA-stability. Forced overexpression of MYLK4 adeno-associated virus was able to partly alleviate the cardiac dysfunction induced by WTAP deletion. Finally, it was surprising that overexpression of WTAP also promotes pathogenic cardiomyocyte hypertrophy both in vitro and in vivo, as well as exacerbated cardiac remolding induced by pressure overload. ConclusionsIn conclusion, our study demonstrates that WTAP is a critical regulator of cardiac function and indicates that appropriate m6A RNA methylation is required for cardiac homeostasis.