miR-21对早期糖尿病肾病db／db小鼠蛋白尿的影响  

Effect of miR-21 on albuminuria in db/db mouse with early stage of diabetic nephropathy

作　　者：张政[1] 彭惠民[1] 陈涛[2] 徐晓明[1] 何晓燕[1] 晏宁[1] 

机构地区：[1]重庆医科大学分子医学与肿瘤研究中心,400016 [2]重庆医科大学附属第一医院

出　　处：《中华内分泌代谢杂志》2010年第8期690-694,共5页Chinese Journal of Endocrinology and Metabolism

基　　金：国家自然科学基金（30800534）

摘　　要：目的了解miR-21对早期糖尿病肾病db／db小鼠24h尿白蛋白、肾小球形态学及其分子机制的影响。方法24只5周龄雄性小鼠分为4组：6只db／m小鼠作为对照组，18只5周龄高血糖且无蛋白尿的db／db小鼠分别随机分为pGenesil—miR-21质粒处理组、对照空质粒处理组及未处理组，每天尾静脉液压法注射质粒30mg·kg^-1·d^-1，直至未处理组db／db小鼠尿白蛋白排泄（UAE）显著高于db／m小鼠组。在光学显微镜下观察肾小球形态大小，计算机计算肾小球面积，实时RT—PCR检测肾脏组织miR-21的表达水平，Western印迹、免疫组化PTEN、p-Akt（Ser473）和P13Kp85d肾脏组织的蛋白质表达水平。结果5周龄db／db小鼠连续注射质粒4周后，未处理组db／db小鼠出现高血糖伴UAE显著增高，提示9周龄db／db小鼠进入早期糖尿病肾病阶段。实时RT-PCR结果显示，在注射pGenesil—miR-21重组质粒的db／db小鼠肾脏组织中，miR-21的表达显著增高（P〈0．01）。光镜观察和肾小球面积测量实验发现，pGenesil-miR-21重组质粒组肾小球显著减小。Western印迹和免疫细胞化学结果显示，miR-21处理组的db／db小鼠肾脏组织中PTEN蛋白较注射对照空质粒和未注射质粒的db／db小鼠组显著降低，而P13K p85α和磷酸化Akt（Ser473）蛋白显著增高（均P〈0．01）。结论miR-21通过特异性靶向调控PTEN／P13K信号传导途径，以抑制肾小球肥大，可能是一个新的糖尿病肾病的保护因子。Objective To explore the effect of miR-21 on 24 h urine albumin excretion （ UAE）, glomeruli morphology, and its molecular mechanism in db/db mouse with early stage of diabetic nephropathy. Methods Twenty-four 5-week-old male mice were randomized into 4 groups： control group （ untreated db/m mice, n = 6） , miR-21 -treated db/db group （ n = 6）, control empty plasmid treated db/db group （ n = 6 ）, and untreated db/db group （n = 6）. Mice were injected intraperitoneally using a hydrodynamics-based procedure with plasmids （30 mg·kg^-1·d^-1 of miR-21 or 30 mg·kg^-1·d^-1 of control plasmid） until albuminuria was detected in the untreated db/db mice. The glomeruli were observed under the light microscope, and measured by the software in the comput- er. The expression of miR-21 was tested by real-time RT-PCR, the expression of PTEN, p-Akt （Ser 473）, and phospbatidylinositol-3-kinase （P[3K） p85a protein levels were examined by western blot and immunohisto-chemistry. Results Male db/db mice of 9-week-old with hyperglycemia and significant elevation of urinary albumin excretion showed features similar to the early stage of diabetic nephropathy. Real-time RT-PCR showed that miR-21 was increased in the miR-21-treated group. By measurement of glomeruli acreage, the glomeruli were smaller in miR-21 -treated group than in the control empty plasmid treated and untreated groups （ all P〈0.01 ）. By Western blot and immunohistochemistry, PTEN were reduced in the miR-21-treated group, whereas PI3K p85α and phospho-Akt （ Ser 473 ） were increased in miR-21-treated group （ all P 〈 0. 01 ）. Conclusions miR-21 ameliorates glomerular hypertrophy in db/db mice with diabetic nephropathy, and it may be a novel protecting factor of diabetic nephropathy.

关 键 词：糖尿病肾病 微RNA PTEN 磷脂酰肌醇3激酶 

分 类 号：R587.2[医药卫生—内分泌]