葡萄子原花青素对糖尿病肾病大鼠非酶糖基化终产物和骨形态蛋白7表达的影响

   目的   研究葡萄子原花青素（GSPE）对糖尿病大鼠非酶糖基化终产物（AGEs）、肾组织结缔组织生长因子（CTGF）及骨形态蛋白7（BMP 7）表达的影响。  方法   将45只链脲佐菌素（STZ）诱导的糖尿病大鼠模型随机分为糖尿病组（DM组，n=15只）、GSPE小剂量［250mg/（kg·d）］治疗组（T1组，n=15只）和大剂量［500mg/（kg·d）］治疗组（T2组，n=15只），另以15只正常大鼠作为对照组（C组），15只正常大鼠给予GSPE 250mg/（kg·d）作为正常治疗组（CT组）。于24周末检测各组大鼠血糖、血清AGEs、血压、24?h尿蛋白定量、血肌酐（Scr）、尿肌酐（Ucr）、肾重/体重水平。以光镜PAS染色及电镜观察肾脏病理改变。用RT PCR、Western blot方法及免疫组化方法检测肾组织中CTGF、BMP-7mRNA及蛋白表达水平的改变。  结果   与C组相比，DM组血清AGEs、血压、24h尿蛋白定量、内生肌酐清除率（Ccr）、肾重/体重均显著升高（P＜0.01），肾病理改变加重，肾组织CTGF mRNA及蛋白表达增加（P＜0.01），而BMP-7mRNA及蛋白降低（P＜0.05）。与DM组相比，T1组和T2组血清AGEs、血压、24h尿蛋白定量、Ccr和肾重/体重显著降低（P＜0.05或P＜0.01），病理改变减轻， BMP-7mRNA及蛋白表达水平升高(P＜0.05或P＜0.01）,而CTGF mRNA及蛋白显著降低（P＜0.01）。T1组与T2组之间相比，Ccr、肾重/体重水平、CTGF mRNA及蛋白差异有统计学意义（P＜0.05或P＜0.01）。   结论    GSPE可以减轻糖尿病大鼠蛋白尿、改善肾脏病理，对其肾脏有明显保护作用，其机制与降低血清AGEs、抑制肾组织CTGF过高表达、上调BMP-7表达有关。

Effects of grape seed proanthocyanidin extracts on advanced glycation end products and expression of bone morphogenetic protein-7 in diabetic nephropathy rats

Objective   To explore the effects of grape seed proanthocyanidin extracts（GSPE） on advanced glycation end products（AGEs）, expression of connective tissue growth factor（CTGF）, and bone morphogenetic protein-7（BMP-7） in diabetic rats.   Methods  45 rats subjected to injection of streptozotocin(STZ) were randomly divided into the diabetic group(DM, n=15), the low dosage GSPE ［250mg/(kg·d)］ treatment group （T1, n=15）, and the high-dosage GSPE ［500mg/(kg·d)］ reatment group（T2, n=15）.　15 normal rats were used as the control group(C), and 15 normal rats were given 250mg/(kg·d)GSPE as the treatment control group(CT). Fasting plasma glucose(FPG), serum AGEs, systolic blood pressure, 24 h urinary protein and ratio of kidney weight to body weight were measured in each rat after 24 weeks. The renal pathological changes were examined with PAS staining and electron microscopy. mRNA and protein expressions of CTGF and BMP 7 in  the kidneys were determined by RT PCR, Western blot and immunohistochemical staining, respectively.   Results   AGEs, blood pressure, 24 h urinary protein, Ccr and ratio of kidney weight to body weight were significantly higher inKG*3] the DM KG*3]group KG*3]than KG*3]thoseKG*3] in KG*3]the C groupP＜0.01）. Renal pathology was heavily damaged in the DM group. Expressions of  mRNA  and protein of CTGF increased in the DM group compared with the C group (P＜0.01), whereas expressions of  mRNA  and protein of BMP-7 decreased (P＜0.05) in the DM group compared with the C group. Treated animals showed a reduction in serum AGEs, proteinuria and systolic blood pressure(P＜0.05 or P＜0.01).　GSPE reduced expressions of  mRNA and protein ofCTGFin the kidneys (P＜0.01),　which contributed to reversal of extracellular matrix(ECM) accumulation in diabetic nephropathy(DN). GSPE increased expressions of  mRNA  and protein of BMP-7 in the kidneys(P＜0.05 or P＜0.01).  Expressions of  mRNA and protein of CTGF, Ccr and ratio of kidney weight to body weight were significantly different between the T1 and T2 group (P＜0.05 or P＜0.01).    Conclusion  These findings suggest that GSPE holds substantial promise for the treatment of DN, and GSPE can decrease  proteinuria and attenuates the progression of nephropathy in diabetic rats. Reno protective effects of GSPE are correlated with its suppression of AGEs, down-regulating expression of CTGF, and up-regulating expression of BMP-7.