近端小管RAS功能轴在早期糖尿病小鼠肾脏中的变化  

Changes of RAS in mouse proximal tubules in early stage of diabetic kidney disease

作　　者：虎璇 杨一菲[1] 韦忠平[1] John S.D.CHAN 苏可[1,2] HU Xuan;YANG Yifei;WEI Zhongping;John S.D.CHAN;SU Ke(Department of Nephrology,Renmin Hospital of Wuhan University,Wuhan 430060,China;University of Montreal Hospital Research Centre(CRCHUM),Quebec H2X 0A9,Canada)

机构地区：[1]武汉大学人民医院肾内科,湖北武汉430060 [2]蒙特利尔大学医院研究中心(CRCHUM),加拿大魁北克省蒙特利尔市H2X 0A9

出　　处：《中国病理生理杂志》2023年第8期1373-1382,共10页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81700559);湖北省自然科学基金资助项目(No.2021CFB360);Canadian Insti⁃tutes of Health Research(PJ9-179813 to JSDC)。

摘　　要：目的:观察自发性糖尿病小鼠模型中,糖尿病肾病早期近端小管肾素-血管紧张素系统(RAS)两条轴[血管紧张素转换酶(ACE)-血管紧张素II(Ang II)-血管紧张素II 1型受体(AT1)经典轴和ACE2-Ang(1-7)-Mas受体(MasR)新轴]的变化特征及对肾脏结构和功能的影响。方法:应用雄性自发性1型糖尿病Akita小鼠(以C57BL/6背景的雄性非糖尿病小鼠为正常对照)和自发性2型糖尿病db/db小鼠(以C57BLKS/J背景的雄性db/m非糖尿病小鼠为正常对照),饲养至16周龄时处死小鼠,测定相应生理指标。收集尿液,检测尿液中Ang II和Ang(1-7)的含量;收取肾脏组织行病理切片染色观察肾脏结构变化;免疫组化法观察肾脏组织血管紧张素原(Agt)、ACE、ACE2和MasR的表达部位及变化;Western blot和RT-qPCR测定近端肾小管的上述蛋白及mRNA的变化。结果:两种糖尿病小鼠16周龄时,肾小球滤过率和尿白蛋白/肌酐比值显著增加(P<0.05),PAS染色可见近端肾小管细胞体积增加,管腔扩张,肾小管肥大,肾小管损伤分数显著增加(P<0.01)。RAS成分检测结果显示,与对照组相比,糖尿病小鼠近端小管Agt和ACE2的蛋白和mRNA表达水平显著升高(P<0.01),尿Ang II排泄显著增加(P<0.01),而ACE和MasR的蛋白和mRNA表达水平显著下调(P<0.01),尿Ang(1-7)含量显著减少(P<0.01)。结论:在自发性糖尿病小鼠中,近端小管RAS在糖尿病肾病早期被激活,激活的RAS可能参与糖尿病肾病早期肾小球高滤过、肾小球和肾小管肥大及近端小管损伤。AIM:To observe the changes of renin-angiotensin system(RAS),including the angiotensin-converting enzyme(ACE)-angiotensin II(Ang II)-Ang II type 1 receptor(AT1)classic axis and the ACE2-Ang(1-7)-Mas receptor(MasR)new axis,in the proximal tubule of diabetic mice,and their effects on kidney structure and function in the early stage of diabetic kidney disease(DKD).METHODS:Male spontaneous type 1 diabetic Akita mice and type 2 diabetic db/db mice were used,and male nondiabetic mice with C57BL/6 background and db/m nondiabetic mice with C57BLKS/J background were used as controls,respectively.At 16 weeks of age,the mice were sacrificed to measure corresponding physiological parameters.Urine was collected,and the levels of Ang II and Ang(1-7)were measured by ELISA.Kidney tissue was collected for pathological section staining to evaluate morphological changes in kidney structure.Immunohistochemistry was used to observe the localization and changes of angiotensinogen(Agt),ACE,ACE2 and MasR in kidney tissues.Western blot and RT-qPCR were used to measure the changes of these proteins and mRNA in isolated proximal renal tubules.RESULTS:The glomerular filtration rate,urinary albumin/creatinine ratio,proximal tubular cell volume,tubular luminal dilation,tubular hypertrophy and tubular injury score were increased in type 1 and type 2 diabetic mice(P<0.05).The Agt and ACE2 expression levels were increased in proximal tubules of diabetic mice compared with control mice(P<0.01),while the ACE and MasR expression levels in proximal tubules of diabetic mice were lower than those in control mice(P<0.01).Urinary Ang II excretion was increased,while urinary Ang(1-7)level was decreased in these 2 types of diabetic mice compared with control mice(P<0.01).CONCLUSION:The proximal tubular RAS in spontaneously diabetic mice is activated in the early stage of DKD.Activation of RAS leads to glomerular hyperfiltration,glomerular and tubular hypertrophy,and proximal tubular injury in the early stage of DKD.

关 键 词：肾素-血管紧张素系统 近端肾小管 糖尿病肾病 自发性糖尿病小鼠 

分 类 号：R587.2[医药卫生—内分泌] R363[医药卫生—内科学]