Selli Cigdem, Erac Yasemin, Kosova Buket, Tosun Metiner
Department of Pharmacology, Faculty of Pharmacy, Ege University, 35100, Izmir, Turkey.
Vascul Pharmacol. 2009 Aug-Sep;51(2-3):96-100. doi: 10.1016/j.vph.2009.04.001. Epub 2009 Apr 20.
This study investigates functional consequences of TRPC1 ion channel downregulation observed in aging rat aorta by employing RNA interference in cultured vascular smooth muscle cells. For this purpose, A7r5 aortic smooth muscle cells were used in quantitative gene and protein expression as well as in functional analyses. According to quantitative RT-PCR results, TRPC3, TRPC4 and TRPC5 mRNAs were not at detectable levels. In siTRPC1-transfected cells, TRPC1 mRNA and protein levels were decreased by 40% and 64%; however, those of TRPC6 were drastically increased by 100% and 200%, respectively. In fura-2-loaded TRPC1 knockdown cells, despite the decreased TRPC1 levels, cyclopiazonic acid-induced Ca2+ entry and store-operated Ca2+ entry following Ca2+ addition were elevated by 77% and 135%, respectively. Results suggest that decrease in TRPC1 may be compensated by upregulated TRPC6 that possibly takes part in store-operated Ca2+ entry in vascular smooth muscle cells.
本研究通过在培养的血管平滑肌细胞中运用RNA干扰技术，调查了衰老大鼠主动脉中观察到的瞬时受体电位通道蛋白1（TRPC1）离子通道下调的功能后果。为此，在定量基因和蛋白质表达以及功能分析中使用了A7r5主动脉平滑肌细胞。根据定量逆转录聚合酶链反应（RT-PCR）结果，TRPC3、TRPC4和TRPC5信使核糖核酸（mRNA）未达到可检测水平。在转染小干扰RNA（siTRPC1）的细胞中，TRPC1 mRNA和蛋白质水平分别下降了40%和64%；然而，TRPC6的水平分别急剧增加了100%和200%。在装载了fura-2的TRPC1基因敲低细胞中，尽管TRPC1水平降低，但环匹阿尼酸诱导的钙离子内流以及添加钙离子后的储存操纵性钙离子内流分别升高了77%和135%。结果表明，TRPC1的减少可能由上调的TRPC6代偿，TRPC6可能参与了血管平滑肌细胞中的储存操纵性钙离子内流。
