肾小管上皮细胞ATP耗竭再恢复时热休克蛋白72与Paxillin的相互作用  

HSP72 interacts with paxillin in ischemic renal tubular epithelial cells

作　　者：毛海萍[1] 李志坚[1] 余学清[1] J.H.Schwartz S.C.Borkan 汪一汗 

机构地区：[1]中山大学附属第一医院肾内科 [2]Renal Section,Department of Medicine,Boston Medical Center,Boston University,USA [3]72211 Little Rock Nephropathology Associates,USA

出　　处：《中华肾脏病杂志》2006年第7期411-415,共5页Chinese Journal of Nephrology

基　　金：广东省自然科学基金(5001708);广东省科技厅国际合作项目(2005850301008);教育部留学回国人员科研启动基金(2005383)

摘　　要：目的研究肾小管上皮细胞ATP耗竭再恢复时热休克蛋白(HSP)72与桩蛋白(Paxillin)的相互作用和意义。方法应用代谢抑制剂暂时性阻断肾小管上皮细胞ATP的生成,引起细胞内的ATP耗竭;换用含10 mmol／L葡萄糖的DMEM培养液,使细胞内ATP再恢复;以热处理细胞或编码HSP72 RNA的腺病毒感染细胞,诱导细胞高表达HSP72。Western印迹检测HSP72水平;间接免疫荧光和Western印迹检测Paxillin在细胞内的分布变化。免疫共沉淀观察HSP72与Paxillin的相互作用。结果肾小管上皮细胞ATP耗竭再恢复时,对照组细胞内的Paxillin由局部黏附结构区域向细胞浆内弥散分布;HSP72由细胞浆转移至细胞膜。细胞高表达HSP72后,HSP72在细胞浆和细胞膜中的蛋白含量均增加(P<0．05);Paxillin由细胞浆向细胞膜的转移明显减少(P<0．05);Paxillin在细胞内的正常分布改善;HSP72和Paxillin之间的相互作用显著增加(P<0．05)。结论肾小管上皮细胞ATP耗竭再恢复时,HSP72可保持Paxillin在细胞内的正常分布特点和区域,其机制可能是HSP72增加与Paxillin的相互作用,发挥分子伴侣的功能。Objective To study the significance and interaction between HSP72 and paxillin in ischemic renal tubular epithelial cells. Methods To induce cells injury, cells were transiently exposed to metabolic inhibitor for 60 rain followed by recovery. The over-expression of wild-type HSP72 was induced by transient heat stress or by infecting opssum kidney（OK） cells with adenovirus containing wild-type human HSP72. Cellular distribution of HSP72 was detected with Western blot. Paxillin distribution was evaluated by and by its solubility in Triton X-IO0 extraction solution. Interaction between HSP72 and paxillin was examined by co-immunoprecipitation. Results In controls, ischemia decreased paxillin staining in focal adhesion plaques. Ischemia also shifted both HSP72 and paxillin from the soluble Triton X-100 to the insoluble pool. In contrast, heat stress increased HSP72 content in the Triton X-100 soluble and Triton X-100 insoluble pools,and prevented paxinin redistribution from focal adhesion plaques. Heat stress or viral infection augmented the interaction between HSP72 and paxillin. Conclusion HSP72 as a molecular chaperone preserves cellular focal adhesion at least partially by increasing direct interaction between HSP72 and paxillin.

关 键 词：热休克蛋白 桩蛋白 细胞骨架 再灌注损伤 腺苷三磷酸 肾小管 上皮细胞 

分 类 号：R692.6[医药卫生—泌尿科学]