Long noncoding RNA Mhrt alleviates angiotensin II-induced cardiac hypertrophy phenotypes by mediating the miR-765/Wnt family member 7B pathway

Long noncoding RNAs (lncRNAs) are known to participate in the pathological process of cardiac hypertrophy. This study aimed to investigate the function of the lncRNA, myosin heavy-chain associated RNA transcript (Mhrt), in cardiac hypertrophy and its possible mechanism of action. Adult mouse cardiomyocytes were treated with angiotensin II (Ang II) and transfected with Mhrt; cardiac hypertrophy was evaluated by estimating atrial natriuretic peptide, brain natriuretic peptide, and beta-myosin heavy-chain levels, and cell surface area by reverse transcription-quantitative polymerase chain reaction, western blotting, and immunofluorescence staining. The interaction between the Mhrt/Wnt family member 7B (WNT7B) and miR-765 was assessed using a luciferase reporter assay. Rescue experiments were performed by analyzing the role of the miR-765/WNT7B pathway underlying the function of Mhrt. The results indicated that Ang II induced hypertrophy of cardiomyocytes; however, overexpression of Mhrt alleviated the Ang II-induced cardiac hypertrophy. Mhrt acted as a sponge for miR-765 to regulate the expression of WNT7B. Rescue experiments revealed that the inhibitory effect of Mhrt on myocardial hypertrophy was abolished by miR-765. Additionally, the knockdown of WNT7B reversed the suppression of myocardial hypertrophy induced by downregulating miR-765. Taken together, Mhrt alleviated cardiac hypertrophy by targeting the miR-765/WNT7B axis.