Objective To investigate the expression and significance of Mannose - binding Lectin A ( MBL - A )in the renal tissuesof early - stage diabetic rats. Methods The Sprague - Dalwley ( SD ) rats were randomly divided into the diabetic and control groups. Streptozotocin ( STZ ) - induced diabetic rat model was established in diahetic group. The expression of MBL - A in renal tissue and apoptosis of renal cells were examined by immunohisochemistry and TUNEL assay, respectively, at 2, 4, 6 and 8 week. MBL - A expression and the renal index of apoptosis ( AI ) were quantified by computer image analysis. The correlations between MBL - A and the renal AI, kidney/body weight ( KI ), and urinary protein excretion were analyzed. Results Significant increase of MBL - A expression in glomeruli and renal AI were observed in diabetic group at 2, 4, 6 and 8 week, when comparing with those in control group ( P ＜ 0. 05 ). Significant correlations were revealed in diabetic group between MBL - A expression and KI or urine protein excretion; between AI and KI or urine protein; and hetween MBL - A expression and AI ( P ＜ 0. 05 ). Conclusion The up - regulated expression of MBL - A and the increased apoptosis of renal cell in early stage DN rats contribute to the development of DN. Their interaction promotes the renal injury of diabetes mellitus.%目的 探讨甘露聚糖结合凝集素-A(mannose-binding lectin A,MBL-A)在早期糖尿病大鼠肾脏中表达的变化规律及其与糖尿病肾病发生发展的关系.方法 将实验大鼠分为模型组和对照组.模型组采用链脲佐菌素诱导糖尿病大鼠模型,分别于造模成功后第2、4、6、8周,用免疫组织化学、TUNEL染色分析和计算机图像分析技术连续多时点观察肾脏MBL-A的表达变化和细胞凋亡情况,并分析两者之间的关系及其与肾脏病理变化指标的相关性.结果 模型组第2、4、6、8周MBL-A蛋白表达均强于对照组,各时间点比较差异有统计学意义;模型组第4、6、8周肾小球细胞凋亡指数(AI)均高于对照组,各时点间差异有统计学意义.模型组MBL-A与尿蛋白、肾脏肥大指数(KI)呈正相关;肾小球细胞AI与尿蛋白、KI呈正相关;MBL-A与细胞AI呈正相关.结论 MBL-A在早期糖尿病大鼠肾脏中表达上调,以肾小球表达上调为主,并随病程延长逐渐增强,其表达变化与糖尿病肾脏病变相关.细胞凋亡也参与了糖尿病早期肾脏病变的变化,激活MBL,两者相互作用,从而促进糖尿病肾病的发展.
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