目的观察整合素连接激酶(ILK)在单侧输尿管梗阻小鼠(UUO)肾脏中的表达,并探讨其在肾小管上皮细胞转化中的作用。方法将10周龄健康雄性 CD-1小鼠随机分为假手术组(C,n=20)和 UUO 组(n=40),分别于术后1、3、7、14 d 处死小鼠。采用 Masson 染色观察肾间质纤维化程度;用免疫组织化学(SP 法)的方法观察 ILK、E-钙黏蛋白(E-cadherin)和α-平滑肌肌动蛋白(α-SMA)的表达;Western blot 半定量分析梗阻侧肾组织 ILK 的蛋白水平;用即时荧光逆转录聚合酶链反应(RT-PCR)检测 ILK、E-cadherin 和α-SMA mRNA 的表达。结果免疫组织化学显示 ILK 在假手术组只有微量表达,主要位于肾小球脏层上皮细胞,UUO 术后1 d ILK 蛋白表达显著增多(t=16.5,P<0.01),7 d 达高峰。术后3 d 肾小管上皮细胞及肾间质α-SMA 阳性细胞数显著增多(t=21.0,P<0.01),肾小管上皮细胞表达 E-cadherin 明显减少(t=5.6,P<0.01)。根据免疫组织化学结果分析,术后1～7 d,ILK 蛋白表达与α-SMA 蛋白表达呈正相关(R=0.88,P<0.01),与 E-cadherin表达呈负相关(R=-0.87,P<0.01)。Western blot 结果显示 ILK 蛋白表达于术后1 d 明显增加,7 d达高峰,14 d 表达不再增加(P>0.05)。RT-PCR 结果显示术后1 d ILK mRNA 表达增多(t=141.6,P<0.01),E-cadherin mRNA 表达于术后3 d 显著减少(P<0.01),α-SMA mRNA 表达于术后3 d 开始增多(P<0.01)。结论 UUO 模型早期整合素连接激酶表达增高,可能通过介导肾小管上皮细胞-间充质转化而参与肾脏纤维化的发生发展。
Objective To review the mechanisms of epithelial to mesenchymal transition （EMT） and its role in the progression of tubulointerstitial fibrosis. Data sources The data used in this review were obtained mainly from the studies of EMT reported from 2000-2006. Study selection Relevant articles on studies of EMT in tubulointerstitial fibrosis were selected. Data were mainly extracted from the 45 articles listed in the reference section of this review. Results The process of EMT has gained wide recognition as candidate mechanism in progression of chronic fibrotic disorders. New markers were identified and facilitate the observation of EMT. EMT is regulated by many factors through activation of kinase-dependent signaling cascades. Recent findings suggest that EMT is a reversible process, which can be controlled by factors for their epithelial inducing activities. Conclusion Remarkable progresses of EMT research have been made recently. Preventing or reversing EMT is a promising strategy against renal fibrosis.
Background Renal hypertrophy has been regarded as the early feature of diabetic nephropathy （DN）, which may eventually lead to proteinuria and renal fibrosis. However, the exact mechanism of renal hypertrophy is still unclear. The aim of this study was to investigate the possible association of connective tissue growth factor （CTGF） with renal hypertrophy in uninephrectomized diabetic rats. Methods Seventy-two Sprague-Dawley （SD） rats were randomly divided into two groups： control group （group C, n=32） and diabetic nephropathy （group DN, n=40）. Each group was re-divided into 4 subgroups according to the experimental period. The rats were sacrificed at 1, 2, 4, and 8 weeks respectively after induction of diabetes. Diabetes was induced by intraperitoneal injection of streptozotocin （STZ） after rats had received uninephrectomy. Blood glucose （BG）, body weight （BW）, 24-h urinary albumin excretion （24hUalb）, kidney weight （KW）, KW/BW, glomerular tuft area （AG）, glomerular tuft volume （VG）, proximal tubular area （AT） at each time point, the width of glomerular basement membrane （GBM） and tubular basement membrane （TBM） at week 8 were measured when the rats were sacrificed. Renal expression of CTGF and p27kipl were detected by immnnohistochemical staining. The relationship between CTGF expression and increasing of VG and AT was analyzed. Results There was a significant increase of 24hUalb, KW, and KW/BW from week 1 onward in diabetic rats compared to those in group C （P〈0.05, respectively）, diabetic rats also had a significant increase of AG, VG, and AT from week 1 onward. It was also shown that diabetic rats had a thickening of GBM [（245.7±103.0） nm vs （121.8±19.1） nm, P〈0.01] and TBM [（767.7±331.1） nm vs （293.0±110.5） nm, P〈0.01] at week 8. There was a weak expression for CTGF and p27kipl in normal glomeruli and tubuli, while a significant increasing expression of CTGF and p27kipl was found in glomeruli and tubuli in diabetic k
LIU Bi-cheng HUANG Hai-quan LUO Dong-dong MA Kun-ling LIU Dian-ge LIU Hong
