Ma Ming, Yang Xiaofei, Han Feng, Wang Haidong
Department of Vascular Surgery, Shanxi Provincial People's Hospital, No. 29 Shuangta East Street, Taiyuan, 030012, Shanxi Province, China.
J Physiol Biochem. 2022 Feb;78(1):245-256. doi: 10.1007/s13105-021-00859-0. Epub 2022 Jan 8.
Abdominal aortic aneurysm (AAA) is a potentially fatal vascular disease, and the dysregulated circular RNAs (circRNAs) play key roles in AAA progression. Circ_0092291 was downregulated in AAA patients, but its function in AAA remains unclear. This research was performed for the functional analysis of circ_0092291 and its mechanism exploration with mircoRNA-626 (miR-626) and collagen type IV alpha1 chain (COL4A1) in AAA. Human aortic vascular smooth muscle cells (T/G HA-VSMC) were treated with angiotensin II (Ang II). Levels of circ_0092291, miR-626, and COL4A1 were determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Inflammatory cytokines were examined by enzyme-linked immunosorbent assay (ELISA). Cell apoptosis was measured using caspase3 activity assay and flow cytometry. Angiopoiesis was assessed via tube formation assay. The protein analysis was conducted by western blot. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP), and RNA pull-down assays were used to validate the molecular binding. Circ_0092291 downregulation was found in AAA samples and Ang II-treated cells. Inflammatory response and cell apoptosis were reduced while angiopoiesis and ECM level were facilitated after overexpression of circ_0092291 in Ang II-treated T/G HA-VSMC cells. MiR-626 was a miRNA target for circ_0092291, and miR-626 inhibition protected T/G HA-VSMC from Ang II-induced cell injury. Moreover, the regulation of circ_0092291 was achieved by serving as a miR-626 sponge in Ang II-treated cells. COL4A1 was affirmed as a target for miR-626 and circ_0092291 resulted in the level change of COL4A1 by sponging miR-626. Additionally, miR-626 downregulation inhibited the cell damages caused by Ang II through increasing the level of COL4A1 and the function of circ_0092291 was attributed to the upregulation of COL4A1. The evidence indicated that circ_0092291 could suppress the Ang II-induced cell dysfunction by targeting the miR-626/COL4A1 signaling axis. Circ_0092291 might improve the diagnosis and treatment of AAA.Key Points.Biological mechanism, Apoptosis, Molecular target.
腹主动脉瘤（AAA）是一种具有潜在致命性的血管疾病，环状RNA（circRNA）表达失调在AAA进展中起关键作用。Circ_0092291在AAA患者中表达下调，但其在AAA中的功能尚不清楚。本研究旨在对circ_0092291进行功能分析，并探讨其与微小RNA-626（miR-626）和IV型胶原α1链（COL4A1）在AAA中的作用机制。用人血管紧张素II（Ang II）处理人主动脉血管平滑肌细胞（T/G HA-VSMC）。采用逆转录定量聚合酶链反应（RT-qPCR）检测circ_0092291、miR-626和COL4A1的水平。通过酶联免疫吸附测定（ELISA）检测炎性细胞因子。使用半胱天冬酶3活性测定和流式细胞术检测细胞凋亡。通过管腔形成试验评估血管生成。通过蛋白质印迹法进行蛋白质分析。采用双荧光素酶报告基因测定、RNA免疫沉淀（RIP）和RNA下拉试验验证分子结合。在AAA样本和Ang II处理的细胞中发现circ_0092291表达下调。在Ang II处理的T/G HA-VSMC细胞中过表达circ_0092291后，炎症反应和细胞凋亡减少，而血管生成和细胞外基质水平升高。MiR-626是circ_0092291的微小RNA靶点，抑制miR-626可保护T/G HA-VSMC免受Ang II诱导的细胞损伤。此外，在Ang II处理的细胞中，circ_0092291通过作为miR-626海绵发挥调节作用。COL4A1被确认为miR-626的靶点，circ_0092291通过结合miR-626导致COL4A1水平改变。此外，下调miR-626可通过增加COL4A1水平抑制Ang II引起的细胞损伤，circ_0092291的功能归因于COL4A1的上调。证据表明，circ_0092291可通过靶向miR-626/COL4A1信号轴抑制Ang II诱导的细胞功能障碍。Circ_0092291可能改善AAA的诊断和治疗。关键点。生物学机制，细胞凋亡，分子靶点。
