中文摘要：

目的：探讨哺乳动物雷帕霉素靶分子复合物（ mTORC）在糖尿病肾病（ DN）小鼠肾组织中的分布、表达。方法14只C57BL/6小鼠随机分成对照组和DN组，每组各7只。 DN组小鼠予以链脲菌素腹腔注射建立小鼠DN模型，采用生化技术检测小鼠血、尿肌酐以及白蛋白水平，组织学染色检测肾脏病理变化，免疫荧光以及免疫印迹技术检测肾组织中mTOR、mTOR 第2448位丝氨酸磷酸化修饰后mTOR （ p-mTOR ）、mTORC1（ Raptor ）、mTORC2（Rictor）以及mTOR信号通路下游的效应蛋白磷酸化 S6K1（p-S6K1）的分布和表达。结果 DN组小鼠血糖、尿白蛋白/肌酐比值明显增加（P＜0．01），肾小球明显增大（P＜0．05）。 mTOR、Raptor以及Rictor在正常以及DN小鼠肾皮质和髓质中均有表达，主要表达在肾小球系膜区、毛细血管袢、皮质近曲小管以及外髓和内髓集合管上皮细胞中。其中正常小鼠内髓肾组织中未见p-S6K1表达，正常以及DN小鼠肾小球中未见p-mTOR表达。免疫印迹检测表明，DN小鼠肾组织中mTOR、p-mTOR、Raptor、Rictor以及p-S6K1均明显上升（P＜0．05）。结论 mTORC广泛分布于小鼠肾组织且参与DN的发生发展，但mTOR第2448位丝氨酸磷酸化并不直接参与高血糖介导的肾小球损伤。

英文摘要：

Objective To investigate the different distribution and expression of mammalian target of rapamycin complex （mTORC） in the kidney of diabetic nephropathy （DN） mice.Methods Fourteen eight-week-old male C57BL/6 mice were assigned to 2 groups： the control group （ n=7 ） and the streptozotocin （ STZ ）-induced DN group （ n=7 ） . Blood and urinary variables including glucose , albumin, creatinine and albumin/creatinine ratio were assessed 2 weeks after STZ injection.Hematoxylin-eosin staining was performed for renal pathological analyses .The distributions of mTOR , phosph-ser2448-mTOR（p-mTOR）, mTORC1（Raptor）, mTORC2（Rictor） and phosph-ser240/244-S6K1 （p-S6K1） were determined by immunofluorescence.The expression levels of mTOR, p-mTOR, mTORC1（Raptor）, mTORC2（Rictor）, S6K1 and p-S6K1 were detected by Western blotting .Results Two weeks after STZ injection , the diabetic mice developed albuminuria （P＆lt;0.01） and renal hypertrophy （P＆lt;0.05）.The immunofluorescence positive staining for mTOR , Raptor, and Rictor was distributed in the epithelial cells of proximal tubules , glomerular mesangium and capillary loops as well as the medullary collecting ducts of the control mouse kidney .These positive signals increased in the DN mouse kidney （ P＆lt;0.05）.However, pS6K1 was not detected in the inner medulla of control mouse and p-mTOR was not found in the glomeruli of both control and DN mice .Conclusion mTORC is widely expessed in the mouse kidney and participates in the development of DN , whereas the 2448 serine phosphorylation of mTOR may be not implicated in the hyperglycemia mediated glomerular injury .