LncRNA GAS5 promotes abdominal aortic aneurysm formation through regulating the miR-185-5p/ADCY7 axis.

One of the causes of abdominal aortic aneurysm (AAA) is the apoptosis of vascular smooth muscle cells. Many long noncoding RNA (lncRNAs) have been implicated in AAA formation. However, the mechanism of growth arrest-specific 5 (GAS5) in AAA formation is not yet clear. The expression levels of GAS5, microRNA-185-5p (miR-185-5p) and adenylate cyclase 7 (ADCY7) were determined by quantitative real-time PCR. Angiotensin II (ANGII) was used to induce AAA cell models. Cell viability was detected by MTT assay, and cell apoptosis was assessed by flow cytometry. Western blot analysis was used to test the protein expression levels. Besides, a dual-luciferase reporter assay was used to identify the mechanism of GAS5. GAS5 was upregulated in AAA tissues and ANGII-induced human aortic smooth muscle cells (HASMCs). GAS5 overexpression inhibited proliferation and promoted apoptosis and inflammatory response in ANGII-induced HASMCs, while its knockdown had the opposite effects. MiR-185-5p could be absorbed by GAS5, and its inhibitor could invert the effects of GAS5 silencing on proliferation, apoptosis and inflammatory response in ANGII-induced HASMCs. ADCY7 was a target of miR-185-5p. ADCY7 knockdown increased proliferation, while decreased apoptosis and inflammatory response in ANGII-induced HASMCs. Also, overexpressed ADCY7 reversed the effect of miR-185-5p overexpression on proliferation, apoptosis and inflammatory response in ANGII-induced HASMCs. GAS5 positively regulated the ADCY7 expression to inhibit the activity of the AKT signaling pathway by sponging miR-185-5p. LncRNA GAS5 contributed to AAA formation through regulating HASMCs proliferation, apoptosis and inflammatory response, which might provide new ideas for the treatment of AAA.