Overexpression of long non-coding RNA ANRIL promotes post-ischaemic angiogenesis and improves cardiac functions by targeting Akt.

Angiogenesis is critical for re-establishing the blood supply to the surviving myocardium after myocardial infarction (MI). Long non-coding RNA ANRIL (lncRNA-ANRIL) has been reported to regulate endothelial functions in cardiovascular diseases. This study was to determine the role of lncRNA-ANRIL in Akt regulation and cardiac functions after MI. Human umbilical vein endothelial cells (HUVECs) were exposed to oxygen-glucose deprivation (OGD) to mimic in vivo ischaemia. The MI model in mice was induced by ligating left anterior descending coronary artery. OGD remarkably decreased lncRNA-ANRIL expression level, reduced the phosphorylated levels of Akt and eNOS proteins, and inhibited NO release and cell viability, which were duplicated by shRNA-mediated gene knockdown of lncRNA-ANRIL. Conversely, all these effects induced by OGD were abolished by adenovirus-mediated overexpression of lncRNA-ANRIL in HUVECs. Further, OGD impaired cell migrations and tube formations in HUVECs, which were reversed by lncRNA-ANRIL overexpression or Akt up-regulation. RNA immunoprecipitation analysis indicated that the affinity of lncRNA-ANRIL to Akt protein was increased in OGD-treated cells. In animal studies, adenovirus-mediated lncRNA-ANRIL overexpression increased the phosphorylated levels of Akt and eNOS, promoted post-ischaemic angiogenesis and improved heart functions in mice with MI surgery. LncRNA-ANRIL regulates Akt phosphorylation to improve endothelial functions, which promotes angiogenesis and improves cardiac functions in mice following MI. In this perspective, targeting lncRNA-ANRIL/Akt may be considered to develop a drug to treat angiogenesis-related diseases.