Department of Cardiovascular, China-Japan Union Hospital of Jilin University, Changchun, China.
Veteran Cadre Department, Changchun Central Hospital, Changchun, China.
Genet Test Mol Biomarkers. 2020 Apr;24(4):204-211. doi: 10.1089/gtmb.2019.0241. Epub 2020 Mar 26.
Atherosclerosis is one of the leading causes of morbidity and mortality worldwide. A variety of long noncoding RNAs (lncRNAs) have been reported to be significantly involved in vascular smooth muscle cell (VSMC) proliferation, which is an essential process for atherosclerotic plaque formation. The aim of this study was to investigate the mechanism of lncRNA urothelial cancer associated 1 (UCA1) involvement in atherosclerosis. The effects of oxidized low-density lipoprotein (oxLDL) and UCA1 on VSMC proliferation and colony-forming ability was measured by 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyl-2H-tetrazolium bromide (MTT) assays, real-time polymerase chain reaction (PCR), and western blots, as well as to determine the effect that oxLDL has on UCA1 expression, and the effect of oxLDL and UCA1 on the expression of cyclin-dependent kinase 2 (CDK2). oxLDL treatment increased the proliferation rate of VSMCs in a concentration-dependent manner. Importantly, UCA1 apparently increased the viability of VSMCs as the VSMCs exhibited a significantly reduced growth rate when UCA1 expression was knocked down by specific small interfering RNAs (siRNAs). In conjunction with increasing cell viability, oxLDL also enhanced the colony-forming ability of VSMCs while UCA1 siRNA decreased the colony-forming ability of VSMCs. Furthermore, UCA1 significantly decreased the percentage of VSMCs in G1 phase, while increasing their percentage in S phase. In contract siRNA knockdown of UCA1 caused an increased percentage of cell in G1 phase, and a reduction in the percentage of cells in S phase. Using real-time PCR and western blot assays, we showed that oxLDL significantly increased the expression levels of UCA1 and CDK2. Furthermore, UCA1 siRNA and CDK2 siRNA almost abolished the positive effect of oxLDL on CDK2 expression. Finally, overexpression of UCA1 induced an increase in CDK2 levels, and knockdown of UCA1 caused inhibition of CDK2 expression. Upregulation of UCA1 enhances abnormal proliferation of VSMC by promoting G1/S transition through modulating the expression of CDK2.
动脉粥样硬化是全球发病率和死亡率的主要原因之一。多种长链非编码 RNA（lncRNA）已被报道与血管平滑肌细胞（VSMC）增殖显著相关，这是动脉粥样硬化斑块形成的一个重要过程。本研究旨在探讨 lncRNA 尿路上皮癌相关 1（UCA1）在动脉粥样硬化中的作用机制。通过 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基-2H-四唑溴盐（MTT）测定、实时聚合酶链反应（PCR）和 Western blot 测定，检测氧化型低密度脂蛋白（oxLDL）和 UCA1 对 VSMC 增殖和集落形成能力的影响，以及 oxLDL 对 UCA1 表达的影响，oxLDL 和 UCA1 对细胞周期蛋白依赖性激酶 2（CDK2）表达的影响。oxLDL 处理以浓度依赖性方式增加 VSMC 的增殖率。重要的是，UCA1 明显增加了 VSMC 的活力，因为当 UCA1 表达被特异性小干扰 RNA（siRNA）敲低时，VSMC 的生长速度明显降低。与增加细胞活力相结合，oxLDL 还增强了 VSMC 的集落形成能力，而 UCA1 siRNA 降低了 VSMC 的集落形成能力。此外，UCA1 显著降低了 G1 期 VSMC 的百分比，同时增加了 S 期的百分比。相反，siRNA 敲低 UCA1 导致 G1 期细胞百分比增加，S 期细胞百分比减少。通过实时 PCR 和 Western blot 测定，我们表明 oxLDL 显著增加了 UCA1 和 CDK2 的表达水平。此外，UCA1 siRNA 和 CDK2 siRNA 几乎消除了 oxLDL 对 CDK2 表达的正向作用。最后，UCA1 的过表达诱导 CDK2 水平升高，而 UCA1 的敲低导致 CDK2 表达抑制。UCA1 的上调通过调节 CDK2 的表达促进 G1/S 期转变，从而增强 VSMC 的异常增殖。
