CAJ | 학술논문

目的研究血管紧张素Ⅱ(AngⅡ)输注对大鼠肾小球ras GTP酶活化蛋白(IQGAPl)表达及细胞凋亡的影响,探讨IQGAP1在AngⅡ诱导肾小球细胞凋亡中的作用.方法 36只雄性Wistar大鼠按随机数字法分为正常对照组、生理盐水输注组和AngⅡ输注组,每隔7d测量大鼠血压及尿蛋白量.分别于实验第14天、第28天处死动物取肾,PAS染色观察肾组织病理学改变；免疫组化、免疫荧光法观察IQGAP1在肾小球的表达及分布；Western印迹法检测肾组织IQGAP1、半胱氨酸蛋白酶3(caspase-3)及细胞外调节蛋白激酶1/2 (ERK1/2)蛋白表达；TUNEL法检测肾小球细胞凋亡.结果 AngⅡ输注组大鼠血压升高,实验第14天达峰值并维持在较高水平；第7天出现蛋白尿,且随时间的延长尿蛋白量持续增加,与对照组比较,差异有统计学意义(P＜0.05).AngⅡ输注组出现轻度系膜细胞增殖和系膜基质增加,生理盐水输注组和正常对照组均未见明显病理改变.TUNEL检测结果显示,AngⅡ输注后肾小球细胞凋亡显著增加；Western印迹发现,AngⅡ输注组大鼠肾小球caspase-3活化明显增加,与对照组比较,差异有统计学意义(P＜0.05).正常对照组IQGAP1呈低水平表达并沿毛细血管袢线性分布,AngⅡ输注后IQGAP1表达量显著增加(P＜0.05),且其蛋白表达量与caspase-3活化量呈正相关(r=0.689,P＜ 0.05).与对照组比较,AngⅡ输注组磷酸化的ERKl/2(p-ERKl/2)表达量显著增加(P＜ 0.05),且与IQGAP1蛋白表达呈正相关(r=0.658,P＜0.05).结论 IQGAP1表达上调可能通过激活ERKl/2信号通路参与AngⅡ诱导肾小球细胞凋亡的病理过程.
목적 연구혈관긴장소Ⅱ(AngⅡ)수주대대서신소구ras GTP매활화단백(IQGAPl)표체급세포조망적영향,탐토IQGAP1재AngⅡ유도신소구세포조망중적작용.방법 36지웅성Wistar대서안수궤수자법분위정상대조조、생리염수수주조화AngⅡ수주조,매격7d측량대서혈압급뇨단백량.분별우실험제14천、제28천처사동물취신,PAS염색관찰신조직병이학개변；면역조화、면역형광법관찰IQGAP1재신소구적표체급분포；Western인적법검측신조직IQGAP1、반광안산단백매3(caspase-3)급세포외조절단백격매1/2 (ERK1/2)단백표체；TUNEL법검측신소구세포조망.결과 AngⅡ수주조대서혈압승고,실험제14천체봉치병유지재교고수평；제7천출현단백뇨,차수시간적연장뇨단백량지속증가,여대조조비교,차이유통계학의의(P＜0.05).AngⅡ수주조출현경도계막세포증식화계막기질증가,생리염수수주조화정상대조조균미견명현병리개변.TUNEL검측결과현시,AngⅡ수주후신소구세포조망현저증가；Western인적발현,AngⅡ수주조대서신소구caspase-3활화명현증가,여대조조비교,차이유통계학의의(P＜0.05).정상대조조IQGAP1정저수평표체병연모세혈관번선성분포,AngⅡ수주후IQGAP1표체량현저증가(P＜0.05),차기단백표체량여caspase-3활화량정정상관(r=0.689,P＜ 0.05).여대조조비교,AngⅡ수주조린산화적ERKl/2(p-ERKl/2)표체량현저증가(P＜ 0.05),차여IQGAP1단백표체정정상관(r=0.658,P＜0.05).결론 IQGAP1표체상조가능통과격활ERKl/2신호통로삼여AngⅡ유도신소구세포조망적병리과정.
Objective To evaluate the effects of Ang Ⅱ on the expression of IQ domain GTPase-activating protein1 (IQGAP1) and apoptosis of glomerular cells,and to explore the role of IQGAP1 in Ang Ⅱ-induced apoptosis of glomerular cells.Methods Thirty-six male Wistar rats were randomly assigned to receive either saline or Ang Ⅱ by osmotic mini-pump,or be used as normal control.The systolic blood pressure and proteinuria were measured at day 7,14,21,28.After the animals were sacrificed at day 14,28 respectively,the kidneys were collected.Renal pathological change,glomerular cell apoptosis were observed.The expression of glomerular IQGAP1 was assessed by immunohistochemistry,immunofluorescence and Western blotting.The activation of caspase-3 and phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2) were determined by Western blotting.Results Ang Ⅱ-infused rats developed significant hypertension and marked proteinuria.Mild glomerular mesangial cell proliferation and mesangial matrix increase were also observed in Ang Ⅱ-infused rats.The number of apoptotic glomerular cells in Ang Ⅱ-infused rats was significantly more than that in normal control (P ＜ 0.05).The expression of IQGAP1 in glomeruli distributed linearly along the capillary loops.Ang Ⅱ infusion up-regulated the expression of glomerular IQGAP1,which had an significantly positive correlation with activation of caspase-3(r =0.689,P ＜ 0.05) and phosphorylation of ERK1/2 (r =0.658,P ＜ 0.05).Conclusion The enhanced expression of IQGAP1 may be involved in Ang Ⅱ-induced glomerular cells apoptosis via activation of ERK1/2 signaling pathway.