摘要
目的:观察2型糖尿病大鼠肾小管上皮细胞转分化过程中的标志蛋白α-平滑肌肌动蛋白、角蛋白18及转化生长因子β1表达变化,分析糖尿病肾病时肾小管病变、肾间质纤维化可能的发生、发展机制。方法:实验于2002-10/2003-05在河北医科大学第二医院完成。纳入二级8周龄雌性SD大鼠40只。随机分为正常对照组和糖尿病组,各20只。通过高糖、高脂饮食加腹腔注射小剂量链脲佐菌素的方法,制作2型糖尿病大鼠模型。分别动态观察12,24周时对照组,糖尿病组大鼠糖尿病肾病时,肾脏的病理改变及功能变化,并同时应用免疫组化技术及流式细胞学技术检测肾小管上皮细胞转分化过程中的标志蛋白:α-平滑肌肌动蛋白、角蛋白18及转化生长因子β1在肾小管上皮细胞中的表达。结果:糖尿病组共成模16只,血糖没有升高的大鼠未纳入结果分析,两组共纳入结果分析36只。①糖尿病组大鼠12周时光镜下可见部分肾小管轻度萎缩或管腔扩张,上皮细胞水肿,胞浆内可见小脂肪空泡,肾小管损伤指数增高;24周时上述变化程度加深,管腔内可见破碎脱落的细胞。24周电镜下可见线粒体部分水肿,嵴大部分消失,微绒毛显著减少,部分肾小管基底膜明显增厚,小管间可见大量胶原纤维。②免疫组化显示:糖尿病组大鼠肾小管上皮细胞胞浆中α-平滑肌肌动蛋白、转化生长因子β1表达增强,角蛋白18表达则下降,它们均随病程进展而加重。③流式测α-平滑肌肌动蛋白及转化生长因子β1表达与免疫组化结果一致,并且与三酰甘油、胆固醇、24h尿白蛋白排泄率明显正相关,与肌酐清除率负相关。结论:在2型糖尿病肾病的发展过程中确实存在小管上皮-肌成纤维细胞转分化,而且转化生长因子β1是其重要的促进因子。小管上皮-肌成纤维细胞转分化与肾功能下降的程度相平行。
AIM： To observe the expression changes of marked proteins： a-smooth muscle actin （α-SMA）, cyte-keratin （CK18） and transforming growth factor-β1 （TGF-β1） in renal tubular epithelial myofibroblast transdifferentiation （TEMT） in rats with Type-2 diabetes mellitus （DM）, and analyze the possible pathologic mechanisms for occurrence and development of renal tubular lesion and renal interstitial fibrosis in diabetic nephropathy （DN）.
METHODS： The experiment was conducted at the Second Hospital of Hebei Medical University between October 2002 and May 2003. Totally 40 female SD rats of 8-week old and Grade 2 were divided into 2 groups： control group and DM group, with 20 in each. Type-2 DM rat models were established by a combination of high-sugar and high-fat diets and small dose of streptozotocin intraperitoneal injection. The pathological and functional changes of DN rats were observed after 12, 24 weeks in both groups. The expressions of α-SMA, CK18, TGF-β1 in renal tubular epithelial cells were detected by immunohistochemical method and flow cytometry in the transforming process.
RESULTS： Totally 16 rats in DM group and 20 rats in the control group were involved in the result analysis, with other 4 rats were excluded because the blood sugar did not increase. ①After 12 weeks, the result of light microscope showed the renal tubules of DM rats atrophied lightly or tube cavity expanded, the epithelial cells presented edema, small fat vacuoles were found in plasma, the injured index of renal tubules increased; After 24 weeks, the above changes became more severer, the deciduous cells were found in the tubules. The result of electron microscope showed the mitochondrion presented edema partly, the cristae disappeared mostly, the microvilli reduced remarkably, part of renal tubular basement membrane thickened obviously, mass collagen fibres were seen between the tubules.②Immunohistochemical result： In the plasma of renal tubular epithelial cell of DM rats, the expressions of α-SMA, TGF-β1 enhanced and the expression of CK18 decreased, which all aggravated with the disease course. ③The detected results of α-SMA and TGF-β1 by flow cytometry were coincided with those by immunohistochemical method. Furthermore, the injured index of renal tubules had significantly positive correlation with triacylglycerol, cholesterol, urine albumin excretory rate, and negative correlation with creatinine clearance rate.
CONCLUSION： TEMT indeed exists in the process of DN in Type-2 DM, and TGF-α1 is a key cytokine of it. TEMT is also paralleled with the decreased level of the renal function.
出处
《中国临床康复》
CSCD
北大核心
2006年第16期57-60,i0003,共5页
Chinese Journal of Clinical Rehabilitation
基金
河北省科技攻关项目(03276196D80)~~
