Journal Article

METTL3 mediates Ang-II-induced cardiac hypertrophy through accelerating pri-miR-221/222 maturation in an m6A-dependent manner

Yao, Yuyu, Chen, Xi, Hao, Chunshu, Ma, Genshan, Ji, Zhenjun, Zuo, Wenjie, Zhang, Rui, Qu, Yangyang, Yang, Mingming, Su, Yamin

2022

Overview

Background METTL3 is the core catalytic enzyme in m6A and is involved in a variety of cardiovascular diseases. However, whether and how METTL3 plays a role during angiotensin II (Ang-II)-induced myocardial hypertrophy is still unknown. Methods Neonatal rat cardiomyocytes (NRCMs) and C57BL/6J mice were treated with Ang-II to induce myocardial hypertrophy. qRT-PCR and western blots were used to detect the expression of RNAs and proteins. Gene function was verified by knockdown and/or overexpression, respectively. Luciferase and RNA immunoprecipitation (RIP) assays were used to verify interactions among multiple genes. Wheat germ agglutinin (WGA), hematoxylin and eosin (H&E), and immunofluorescence were used to examine myocardial size. m6A methylation was detected by a colorimetric kit. Results METTL3 and miR-221/222 expression and m6A levels were significantly increased in response to Ang-II stimulation. Knockdown of METTL3 or miR-221/222 could completely abolish the ability of NRCMs to undergo hypertrophy. The expression of miR-221/222 was positively regulated by METTL3, and the levels of pri-miR-221/222 that bind to DGCR8 or form m6A methylation were promoted by METTL3 in NRCMs. The effect of METTL3 knockdown on hypertrophy was antagonized by miR-221/222 overexpression. Mechanically, Wnt/β-catenin signaling was activated during hypertrophy and restrained by METTL3 or miR-221/222 inhibition. The Wnt/β-catenin antagonist DKK2 was directly targeted by miR-221/222, and the effect of miR-221/222 inhibitor on Wnt/β-catenin was abolished after inhibition of DKK2. Finally, AAV9-mediated cardiac METTL3 knockdown was able to attenuate Ang-II-induced cardiac hypertrophy in mouse model. Conclusions Our findings suggest that METTL3 positively modulates the pri-miR221/222 maturation process in an m6A-dependent manner and subsequently activates Wnt/β-catenin signaling by inhibiting DKK2, thus promoting Ang-II-induced cardiac hypertrophy. AAV9-mediated cardiac METTL3 knockdown could be a therapeutic for pathological myocardial hypertrophy.

• Publisher: BioMed Central,BMC
• Subject: Angiotensin II / Biochemistry / Biological and Medical Physics / Biomedical and Life Sciences / Biophysics / Biotechnology / Cardiac hypertrophy / Cell Biology / Life Sciences / METTL3 / miR-221/222 / Molecular Medicine / Wnt/β-catenin signaling