CAJ | 학술논문

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。
목적：탐토포유동물뢰파매소파분자복합물（ mTORC）재당뇨병신병（ DN）소서신조직중적분포、표체。방법14지C57BL/6소서수궤분성대조조화DN조，매조각7지。 DN조소서여이련뇨균소복강주사건립소서DN모형，채용생화기술검측소서혈、뇨기항이급백단백수평，조직학염색검측신장병리변화，면역형광이급면역인적기술검측신조직중mTOR、mTOR 제2448위사안산린산화수식후mTOR （ p-mTOR ）、mTORC1（ Raptor ）、mTORC2（Rictor）이급mTOR신호통로하유적효응단백린산화 S6K1（p-S6K1）적분포화표체。결과 DN조소서혈당、뇨백단백/기항비치명현증가（P＜0．01），신소구명현증대（P＜0．05）。 mTOR、Raptor이급Rictor재정상이급DN소서신피질화수질중균유표체，주요표체재신소구계막구、모세혈관번、피질근곡소관이급외수화내수집합관상피세포중。기중정상소서내수신조직중미견p-S6K1표체，정상이급DN소서신소구중미견p-mTOR표체。면역인적검측표명，DN소서신조직중mTOR、p-mTOR、Raptor、Rictor이급p-S6K1균명현상승（P＜0．05）。결론 mTORC엄범분포우소서신조직차삼여DN적발생발전，단mTOR제2448위사안산린산화병불직접삼여고혈당개도적신소구손상。
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<0.01) and renal hypertrophy (P<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<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 .