精甘天丝四肽对人肾小球系膜细胞肌动蛋白及凋亡的影响

观察精-甘-天-丝(RGDS)四肽对肾小球系膜细胞肌动蛋白及凋亡的影响,以探讨细胞外基质(ECM)-整合素-细胞骨架的相互作用机制。方法 共聚焦显微镜观察肾小球系膜细胞肌动蛋白微丝的变化;以流式细胞仪和DNA电泳方法检测细胞凋亡。结果 用RGDS肽处理2小时后,系膜细胞开始由梭形变为圆形或卵圆形,同时细胞质的肌动蛋白微丝亦由弥漫分布变为聚集成团,居于细胞质一侧,形成着边现象,这些细胞继而脱壁、悬浮于培养上清中,脱落细胞经碘化丙啶染色见细胞核固缩、破碎。至第10小时RGDS处理组的系膜细胞大都脱壁,脱落细胞的DNA电泳呈现梯形条带,流式细胞仪分析显示处理组系膜细胞中出现了低二倍体细胞群(A_0峰),证实处理组的脱落细胞发生了细胞凋亡。在实验观察期间对照组的系膜细胞始终呈贴壁状态生长,细胞质肌动蛋白微丝呈弥漫分布。结论 RGDS肽可以使肾小球系膜细胞细胞骨架肌动蛋白微丝分布异常,导致肾小球系膜细胞变形、脱壁和凋亡。

Effects of RGDS tetrapeptide on the actin and apoptosis in human glomerular mesangial cells

Observing the effects of Arg-Gly-Asp-Ser(RGDS) peptides on the actin organization and apoptosis in human glomerular mesangial cells, in order to explore the interaction mechanism of extracellular matrix (ECM)-integrin receptor-cy-toskeleton. Methods The alterations of actin microfilaments in glomerular mesangial cells were observed under laser scanning confocal microscope. And DNA electrophoresis and flowcytometry were used for assessing apoptosis. Results After two hours of incubation with RGDS peptides, some of the attached glomerular mesangial cells began to round up, with a prominent marginaliza-tion of the actin microfilaments which were bundled in thick aggergates to one edge of the cell. Later these cells detached and floated in the culture medium.The above sequently-occuring changes showed a time-dependent pattern. After ten hours of incubation with RGDS peptide, most of the cells had detached, and features of apoptosis appeared in them, such as inter-nucleo-somal DNA fragmentation and decreased DNA content. Conclusion RGDS tetrapeptide can disrupt the organization of cytoplasmic actin mi-crofilament, inhibit the attachment of the cultured glomerular mesangial cells and cause apoptosis in them.