增龄引起复制性衰老细胞胞内钙信号转导的变化

为了观察血管紧张素Ⅱ (AngⅡ )引起复制性衰老细胞胞内游离钙的变化以及衰老对其的影响 ,初步阐明衰老引起胞内游离钙变化的机制 .选用人胚肺二倍体成纤维细胞WI 38细胞株 ,利用逆转录PCR(RT PCR)技术及Northern杂交技术检测衰老细胞血管紧张素Ⅱ 1型受体 (AT1R)、血管紧张素Ⅱ 2型受体 (AT2R)mRNA水平的表达 ;利用激光共聚焦显微成像技术 (LSCM )观察WI 38细胞在AngⅡ刺激 ,Valsartan阻断条件下细胞内钙离子荧光强度的改变 .AngⅡ通过AT1受体介导增加WI 38细胞内游离钙的水平 ,并随着WI 38细胞传代增加至衰老状态 ,AT2受体高表达 ,AT1受体介导的钙离子信号转导的活性逐渐降低 .提示WI 38细胞衰老过程中钙离子信号的转导活性降低 ,并且AT1R和AT2R在血管紧张素Ⅱ介导的细胞内钙信号活性中具有不同的作用与机制 .为探讨WI 38衰老细胞内钙信号变化机制提供了实验依据

Aging Related Calcium Singal Transduction Change in Replicative Senescence Cells

The normal human fetal lung diploid fibroblast cell line, WI 38, was used to investigate aging related intercellular calcium singal transduction change with the stimulation of angiotensinⅡ (AngⅡ) for exploring the mechanism of the change with aging.AngiotensinⅡ 1 receptor (AT1R) and angiotensionⅡ 2 receptor (AT2R) subtypes messenger RNA (mRNA) levels were detected by RT PCR and Northern blotting.WI 38 cells were stained with Fluo 3/AM and the change of intensity was observed in the presence of stimulator(angiotensinⅡ) and inhibitor(valsartan) by laser scanning confocal microscopy.The result demonstrated that AngⅡ could increase the level of intercellular calcium via the AT1 receptor on the surface of WI 38 cells. As the culture passage increased the expression of AT2 receptor increased and the AT1 receptor mediated activity of calcium signal transduction was inhibited.