Long non-coding RNA CHRF facilitates cardiac hypertrophy through regulating Akt3 via miR-93

Background: Non-coding RNAs, including long non-coding RNAs (IncRNAs) and microRNAs (miRNAs), have been demonstrated as central mediators in cardiac hypertrophy responses. LncRNA cardiac hypertrophy related factor (CHRF) has been reported to be implicated in cardiac hypertrophy. However, the underlying mechanisms of CHRF have not been thoroughly elucidated. Methods: Expressions of CHRF and microRNA-93 (miR-93) in heart tissues and cardiomyocytes were detected by RT-ciPCR assay. Cell surface area, protein/DNA ratio, atrial natriuretic peptide (ANP) and beta-myosin heavy chain (beta-MHC) levels were examined as the indicators of cardiac hypertrophy responses. Luciferase reporter assay was used to validate the direct binding between miR-93 and CHRF or Akt3 3'UTR. RIP assay was performed to demonstrate the potential interaction between CHRF and miR-93. Akt3 protein level was determined by western blot assay. Results: CHRF expression was up-regulated and miR-93 expression was down-regulated in mice and cellular models of cardiac hypertrophy. CHRF knockdown attenuated isoproterenol (Iso)-induced hypertrophy responses through up-regulating miR-93 expression in cardiomyocytes. Moreover, CHRF acted as a competing endogenous RNA of miR-93 to sequester miR-93 from Akt3, resulting in the increase of Akt3 expression. Furthermore, miR-93 suppressed cardiac hypertrophy responses by targeting Akt3 in Iso-stimulated cardiomyocytes. Conclusions: CHRF induced cardiac hypertrophy by regulating miR-93/Ak1.3 axis in Iso-slimulated cardiomyocytes, deepening our understanding of the molecular mechanisms of IncRNAs in cardiac hypertrophy and providing a potential therapy target for cardiac hypertrophy. (C) 2018 Elsevier Inc. All rights reserved.