【摘要】 目的探讨血管紧张素Ⅱ(AngⅡ)1A型(AT1A)受体基因对糖尿病嵌合体 (chimeric)小鼠肾脏细胞外基质的影响。方法嵌合体小鼠全身组织包括肾脏由AngⅡ1A型受体(AT1A)野生型细胞(AT1A+／+)和AngⅡ受体AT1A基因敲除细胞(AT1A-／-)两组不同克隆来源的细胞组成。在AT1A嵌合体小鼠腹腔内注射链尿佐菌素(STZ,300 mg／kg),诱导糖尿病模型 12周后,取肾脏组织作连续冰冻切片。β半乳糖苷酶(LacZ)染色区分不同基因型的肾小球。 PAS染色检测其细胞外基质的表达。免疫组化方法检测转化生长因子(TGF)β1、纤溶酶原激活物抑制物(PAI)1、终末糖基化产物(AGE)、硝基酪氨酸(nitrotyrosine)的表达。比较两种基因型肾小球细胞外基质和各细胞因子的表达变化。结果在糖尿病状态下,AT1A+／+和AT1A-／-小鼠肾小球细胞外基质均较对照组明显增多(P<0．05)。两种基因型相比,AT1A-／-基因型肾小球的表达绝对值显著高于AT1A+／+基因型肾小球(P<0．05)。但从正常状态到糖尿病形成过程中, 其升高幅度却显著低于AT1A+／+基因型肾小球(P<0．01)。各种细胞因子在糖尿病状态下的表达均显著增加(P<0．05),AT1A-／-基因型肾小球的绝对数值显著高于AT1A+／+基因型肾小球 (P<0．05),但AT1A-／-基因型肾小球细胞因子表达的变化幅度低于AT1A+／+基因型肾小球 (P<0.01)。结论 AT1A基因缺失使得部分肾小球代偿性上调TGF-β1、PAI-1、AGE和nitrotyrosine 的表达。AT1A受体在一定程度上影响了TGF-β1、PAI-1、AGE和nitrotyrosine的表达而参与了糖尿病小鼠肾脏细胞外基质的重塑,但并非独立决定因素。更多还原

【Abstract】 Objective To explore the effects of AT1A receptor on extracellular matrix remolding in diabetic mice. Methods Chimeric mice carried AT1A-deficient (Agtrla -/-) and intact cells. AT1A-intact cells within the kidney can be stained ubiquitously by β-galactosidase. Hyperglycemia was induced by peritoneal injection of streptozotocin in male chimeric mice at the age of 6 months. At week 12, kidneys were harvested and were frozen quickly in dry ice-acetone. LacZ staining and immunohistochemistry were performed on serial frozen section. Extracellular matrix index was measured by PAS staining. The expression levels of TGF-β1, PAI-1, AGE, andnitrotyrosine were semi-quantitated by immunohistochemical method in LacZ-positive (AT1A-intact cells) and LacZ-negative (AT1A-deficient) glomeruli respectively. Results The expression levels of ECM, TGF-β1, PAI-1, AGE, and nitrotyrosine in glomeruli of both kinds were increased significantly in diabetic mice compared with those in control mice(P<0.05). The expression levels of ECM , TGF-BBBBBBBBBBBBB1, PAI-1, AGE, and nitrotyrosine in AT1A-deficient glomerulus were higher than those in AT1A-intact glomeruli of normal chimeric mice(P<0.05), but the increasing extent in AT1A-deficient glomerulus was less obvious than that of AT1A -intact glomeruli (P<0.01). Conclusions The deficience of AT1A resulted in compensative upregulation of TGF-β1 , PAI-1, AGE, and nitrotyrosine in glomeruli. Although not being a predominantly independent factor, local RAS plays a certain role in extracellular matrix remolding by manipulation the expression of TGF-β1, PAI-1, AGE, and nitrotyrosine in the kidney of diabetic mice. Further studies are needed to explore the whole scenario.更多还原