鉴定尿可溶性E-钙黏蛋白作为糖尿病肾病的一种新型生物标志物。

Identification of urinary soluble E-cadherin as a novel biomarker for diabetic nephropathy.

作者信息

Jiang Hongjuan, Guan Guangju, Zhang Rui, Liu Gang, Cheng Jing, Hou Xianghua, Cui Yazhou

机构信息

Department of Nephrology, The Second Hospital of Shandong University, 247 Beiyuan Road, Jinan, Shandong, PR China.

出版信息

Diabetes Metab Res Rev. 2009 Mar;25(3):232-41. doi: 10.1002/dmrr.940.

DOI:10.1002/dmrr.940

PMID:19177462

Abstract

BACKGROUND

Currently, early diagnosis of diabetic nephropathy (DN) remains a major challenge. Thus, more investigations into new DN-related biomarkers are needed.

METHODS

We employed urinary proteomic approach of fluorescence-based difference gel electrophoresis (DIGE) and mass spectrometry to identify novel biomarkers in urine samples, which were from type 2 diabetes patients with normoalbuminuria (DM group), microalbuminuria (DN1 group), macroalbuminuria (DN2 group) and control group (n=8 in each group). The identified biomarker was further studied by western blot in urine samples (n=6 in each group) and immunohistochemistry in renal biopsies. Besides, the urinary level of biomarker was detected and analyzed using enzyme-linked immunosorbent assay(ELISA) method (n=40 in each group).

RESULTS

A novel DN-related biomarker, urinary E-cadherin, was identified by proteomic methods, which up-regulated 1.3-fold, 5.2-fold and 8.5-fold in DM, DN1 and DN2 groups compared with control group. Meanwhile, high expression of urinary soluble 80 kDa fragment of E-cadherin (sE-cadherin) was verified in DN groups by western blot. The ELISA data also demonstrated that urinary sE-cadherin-to-creatinine ratio was significantly increased in DN1 and DN2 groups versus DM group or control group (2751.5+/-164 and 5839.6+/-428 vs 721.9+/-93 or 652.7+/-87 microg/g; p<0.001). The sensitivity and specificity of urinary sE-cadherin for diagnosis of DN were calculated as 78.8% (95% CI, 74-83%) and 80% (95% CI, 65-91%). Besides, immunohistochemical stain showed that E-cadherin expression was markedly decreased in renal tubular epithelial cells of patients with DN versus healthy controls.

CONCLUSIONS

Urinary sE-cadherin has a potential clinical diagnostic value for DN and E-cadherin may participate in the pathogenesis of DN.

摘要

背景

目前，糖尿病肾病（DN）的早期诊断仍然是一项重大挑战。因此，需要对新的DN相关生物标志物进行更多研究。

方法

我们采用基于荧光的差异凝胶电泳（DIGE）和质谱的尿液蛋白质组学方法，在尿样中鉴定新的生物标志物，这些尿样来自2型糖尿病正常白蛋白尿患者（糖尿病组）、微量白蛋白尿患者（DN1组）、大量白蛋白尿患者（DN2组）和对照组（每组n = 8）。通过蛋白质印迹法在尿样（每组n = 6）中以及免疫组织化学法在肾活检组织中对鉴定出的生物标志物进行进一步研究。此外，使用酶联免疫吸附测定（ELISA）方法检测并分析生物标志物的尿水平（每组n = 40）。

结果

通过蛋白质组学方法鉴定出一种新的DN相关生物标志物——尿E-钙黏蛋白，与对照组相比，其在糖尿病组、DN1组和DN2组中分别上调了1.3倍、5.2倍和8.5倍。同时，通过蛋白质印迹法在DN组中证实了尿E-钙黏蛋白80 kDa可溶性片段（sE-钙黏蛋白）的高表达。ELISA数据还表明，与糖尿病组或对照组相比，DN1组和DN2组的尿sE-钙黏蛋白与肌酐比值显著升高（2751.5±164和5839.6±428 vs 721.9±93或652.7±87μg/g；p < 0.001）。计算得出尿sE-钙黏蛋白诊断DN的敏感性和特异性分别为78.8%（95%CI，74 - 83%）和80%（95%CI，65 - 91%）。此外，免疫组织化学染色显示，与健康对照相比，DN患者肾小管上皮细胞中E-钙黏蛋白表达明显降低。