Identification of Rack1, EF-Tu and Rhodanese as Aging-Related Proteins in Human Colonic Epithelium by Proteomic Analysis
Identification of Rack1, EF-Tu and Rhodanese as Aging-Related Proteins in Human Colonic Epithelium by Proteomic Analysis
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DOI：
10.1021/pr9009386
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发表时间：
2010-03-01
影响因子：
4.4
通讯作者：
Xiao, Zhi-Qiang
中科院分区：
文献类型：
--
作者：
Yi, Hong;Li, Xin-Hui;Xiao, Zhi-Qiang
人结肠上皮细胞的衰老过程包括生理活力的缓慢下降和对与年龄相关的疾病，特别是结肠癌的易感性增加，但其机制仍有待阐明。为了揭示结肠上皮衰老的分子基础，我们用蛋白质组学的方法从年轻人和老年人的正常结肠上皮组织中筛选差异蛋白质。结果用双向电泳法和质谱法鉴定了17个差异蛋白，并用免疫组织化学方法对部分差异蛋白进行了确认。进一步研究了Rack1、EF-Tu和Rhodanes这三种已被证实的差异蛋白在体外细胞衰老中的作用。Western印迹结果显示，D-半乳糖诱导的衰老NIH/3T3细胞中这三种蛋白的表达均较对照细胞下调。此外，siRNA下调Rack1基因可促进NIH/3T3细胞衰老。综上所述，Rack1、EF-Tu和Rhodanes是人结肠上皮细胞的衰老相关蛋白，线粒体功能损伤和抗氧化能力下降是人结肠上皮细胞衰老的重要原因。
The aging process of human colonic epithelium involves a slow decline in physiological vigor and an increasing susceptibility to age-related diseases, especially, colon cancer, but the mechanisms still remain to be elucidated. To reveal the molecular bases of colonic epithelial aging, a proteomic approach was used to screen for differential proteins in the human normal colonic epithelial tissues from young and old people. As a result, 17 differential proteins were identified by two-dimensional electrophoresis and mass spectrometry, and the partial differential proteins were confirmed by immunohistochemistry. Rack1, EF-Tu and Rhodanese, three validated differential proteins, were further investigated for their role in the in vitro cell senescence. Western blot showed that the expression of all the three proteins was downregulated in the senescent NIH/3T3 cells induced by D-galactose as compared to the control cells. Furthermore, knockdown of Rack1 by siRNA could promote NIH/3T3 cell senescence. Taken together, our results suggest that Rack1, EF-Tu and Rhodanese are aging-related proteins in human colonic epithelium, and injury of mitochondrial function and decline of antioxidant capability are important reasons for the aging of human colonic epithelium.