Department of Thoracic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China.
Department of Cardiology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China.
Cardiovasc Pathol. 2018 Jul-Aug;35:29-36. doi: 10.1016/j.carpath.2018.04.003. Epub 2018 Apr 11.
Non-coding RNAs, including long non-coding RNAs (lncRNAs) 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.
Expressions of CHRF and microRNA-93 (miR-93) in heart tissues and cardiomyocytes were detected by RT-qPCR assay. Cell surface area, protein/DNA ratio, atrial natriuretic peptide (ANP) and β-myosin heavy chain (β-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.
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.
CHRF induced cardiac hypertrophy by regulating miR-93/Akt3 axis in Iso-stimulated cardiomyocytes, deepening our understanding of the molecular mechanisms of lncRNAs in cardiac hypertrophy and providing a potential therapy target for cardiac hypertrophy.
非编码 RNA，包括长非编码 RNA（lncRNA）和 microRNA（miRNA），已被证明是心脏肥大反应的重要介质。lncRNA 心脏肥大相关因子（CHRF）已被报道与心脏肥大有关。然而，CHRF 的潜在机制尚未得到充分阐明。
通过 RT-qPCR 检测心脏组织和心肌细胞中 CHRF 和 microRNA-93（miR-93）的表达。细胞表面积、蛋白/DNA 比、心房利钠肽（ANP）和β-肌球蛋白重链（β-MHC）水平被检测为心脏肥大反应的指标。荧光素酶报告基因检测用于验证 miR-93 和 CHRF 或 Akt3 3'UTR 之间的直接结合。RIP 实验用于证明 CHRF 和 miR-93 之间的潜在相互作用。通过 Western blot 检测 Akt3 蛋白水平。
在心脏肥大的小鼠和细胞模型中，CHRF 表达上调，miR-93 表达下调。在心肌细胞中，CHRF 敲低通过上调 miR-93 表达来减弱异丙肾上腺素（Iso）诱导的肥大反应。此外，CHRF 作为 miR-93 的竞争性内源性 RNA，将 miR-93 从 Akt3 上隔离出来，导致 Akt3 表达增加。此外，miR-93 通过在 Iso 刺激的心肌细胞中靶向 Akt3 抑制心脏肥大反应。
CHRF 通过调节 Iso 刺激的心肌细胞中 miR-93/Akt3 轴诱导心脏肥大，加深了我们对 lncRNA 在心脏肥大中的分子机制的理解，并为心脏肥大提供了一个潜在的治疗靶点。
