Relationship between E - cadherin and diabetic nephropathy

Objective To identify novel biomarker for diabetic nephropathy (DN) by urinary proteomic methods, and to detect the expression of E-cadherin in urine and renal tissue of patients with DN. Methods Urine samples were collected from 12 cases of type 1 diabetic nephropathy patients (T1DN), 12 cases of type 2 diabetic nephropathy patients (T2DN), 12 cases of nephritic syndrome patients (NS), and 12 cases of healthy Controls. Comparative proteomic approach of two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were employed to identify DN-related biomarker in urine samples. The differential expression of the identified biomarker in urine samples and renal biopsy specimens were detected by Western blotting and immunohistochemistry method. Results E-cadherin was identified by 2DE/MS, which was significantly up-regulated in T1DN and T2DN groups (all P＜ 0.01). Western blotting confirmed the expression of E-cadherin was significantly higher in T1DN and T2DN groups than in NS and Control groups (all P＜0.01). Immunohistochemical stain showed E-cadherin was mainly expressed in the membrane and cytoplasm of renal tubular epithelial cell, and its expression was markedly decreased in DN kidneys compared with healthy Controls (P＜0.05). Conclusions E-cadherin is identified as a novel DN-related biomarker, which is specifically increased in urine of DN patients.