title: Dipeptidyl peptidase-IV is a potential molecular biomarker in diabetic kidney disease.
abstract: 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.
authors.affiliation: The Second Hospital of Shandong University, Ji'nan, Shandong, People's Republic of China.
authors.forename: Ai-li
authors.initials: AL
authors.lastname: Sun
authors.forename: Jing-ti
authors.initials: JT
authors.lastname: Deng
authors.forename: Guang-ju
authors.initials: GJ
authors.lastname: Guan
authors.forename: Shi-hong
authors.initials: SH
authors.lastname: Chen
authors.forename: Yuan-tao
authors.initials: YT
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Cheng
authors.forename: Zhen-wei
authors.initials: ZW
authors.lastname: Li
authors.forename: Xiang-hua
authors.initials: XH
authors.lastname: Zhuang
authors.forename: Fu-dun
authors.initials: FD
authors.lastname: Sun
authors.forename: Hao-ping
authors.initials: HP
authors.lastname: Deng
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000175:diagnosis / Q000201:enzymology / Q000209:etiology / Q000652:urine; D015415:Biomarkers / Q000097:blood / Q000652:urine; D015153:Blotting, Western; D016022:Case-Control Studies; D002498:Centrifugation; D003404:Creatinine / Q000652:urine; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003928:Diabetic Nephropathies / Q000097:blood / Q000175:diagnosis / Q000201:enzymology* / Q000209:etiology / Q000652:urine; D018819:Dipeptidyl Peptidase 4 / Q000097:blood / Q000652:urine*; D004797:Enzyme-Linked Immunosorbent Assay; D055354:Exosomes / Q000201:enzymology / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007677:Kidney Function Tests; D016014:Linear Models; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D016482:Urinalysis; D014556:Urine / Q000737:chemistry / Q000166:cytology
chemical_list: D015415:Biomarkers; D003404:Creatinine; C042807:DPP4 protein, human; D018819:Dipeptidyl Peptidase 4