The Second Hospital of Shandong University, Ji'nan, Shandong, People's Republic of China.
Diab Vasc Dis Res. 2012 Oct;9(4):301-8. doi: 10.1177/1479164111434318. Epub 2012 Mar 2.
The present study was designed to identify the changes in microvesicle-dipeptidyl peptidase-IV (DPP IV) levels in human urine and serum, and to determine whether there were correlations with the severity of diabetic kidney disease (DKD). A total of 127 patients with type 2 diabetes mellitus (T2DM) were divided into three groups according to the urinary albumin/ creatinine ratio (UACR): microalbuminuria group (n = 50); macroalbuminuria group (n = 34) and normoalbuminuria group (n = 43), and 34 age- and sex-matched non-diabetic healthy subjects were selected as controls. Microvesicle-bound DPP IV and free urinary DPP IV were separated by a filtra-centrifugation method. The total microvesicles were captured by a specific monoclonal antibody, AD-1. DPP IV activity was determined by measuring the cleavage of chromogenic free 4-nitroaniline from Gly-Pro-p-nitroanilide at 405 nm with an ELISA plate reader. DPP IV protein levels were determined by ELISA and Western blot. Our results showed that the microvesicle-bound type was the major form of DPP IV in urine; the urinary microvesicle-DPP IV excretion of each T2DM group was significantly higher compared with controls. The urinary microvesicle-DPP IV level was positively correlated with UACR in patients with T2DM. These findings suggest that the urinary level of microvesicle-bound DPP IV is associated with the severity of DKD.
本研究旨在鉴定人尿液和血清中小微囊泡二肽基肽酶-IV（DPP IV）水平的变化，并确定其与糖尿病肾病（DKD）严重程度的相关性。共纳入 127 例 2 型糖尿病患者（T2DM），根据尿白蛋白/肌酐比值（UACR）分为三组：微量白蛋白尿组（n = 50）；大量白蛋白尿组（n = 34）和正常白蛋白尿组（n = 43），并选择 34 例年龄和性别匹配的非糖尿病健康受试者作为对照。采用超滤离心法分离微囊泡结合型 DPP IV 和游离型尿 DPP IV。用特异性单克隆抗体 AD-1 捕获总微囊泡。用酶联免疫吸附试验（ELISA）板阅读器测定色原性游离 4-硝基苯胺从 Gly-Pro-p-硝基苯胺的裂解，以测定 DPP IV 活性。用 ELISA 和 Western blot 法测定 DPP IV 蛋白水平。我们的结果表明，微囊泡结合型是尿中 DPP IV 的主要形式；各 T2DM 组的尿微囊泡-DPP IV 排泄量均明显高于对照组。T2DM 患者的尿微囊泡-DPP IV 水平与 UACR 呈正相关。这些发现表明，尿中小微囊泡结合型 DPP IV 的水平与 DKD 的严重程度相关。
