Proteome analysis of serum from type 2 diabetics with nephropathy.
Diabetic nephropathy (DN) is a renal disease which develops as a consequence of diabetes mellitus. Microalbuminuria is the earliest clinical sign of DN. There are no specific diagnostic biomarkers for type 2 diabetics with nephropathy other than microalbuminuria and macroalbuminuria. However, microalbuminuria does not constitute a sole independent indicator for type 2 diabetics with nephropathy, and thus, another screening method, such as a biomarker assay, is required in order to diagnose it more correctly. Therefore, we have utilized two-dimensional electrophoresis (2-DE) to identify human serum protein markers for the more specific and accurate prediction of progressive nephropathy in type 2 diabetes patients, via comparisons of the serum proteome in three experimental groups: type 2 diabetes patients without microalbuminuria (DM, n = 30), with microalbuminuria (MA, n = 29), and with chronic renal failure (CRF, n = 31). As a result, proteins which were differentially expressed with statistical significance (p < 0.05) in MA and CRF groups as compared to those in DM group were selected and identified by ESI-Q-TOF MS/MS. Among these identified proteins, two proteins which might be useful as diagnostic biomarkers of type 2 diabetics with nephropathy were verified by Western blotting: extracellular glutathione peroxidase (eGPx) and apolipoprotein (ApoE) were found to exhibit a progressive reduction in MA and CRF groups. Notably, eGPx was further verified by ELISA using DM (n = 100) and MA (n = 96) patient samples. Collectively, our results show that the two proteins identified in this study may constitute potential biomarkers for the diagnosis of type 2 diabetics with nephropathy.
Kim
Hyun-Jung
HJ
School of Life Sciences and Biotechnology, Korea University, 1, 5 ka, Anam-dong, Sungbuk-ku, Seoul 136-701, Korea.
Cho
Eun-Hee
EH
Yoo
Ji-Hye
JH
Kim
Pan-Kyeom
PK
Shin
Jun-Seop
JS
Kim
Mi-Ryung
MR
Kim
Chan-Wha
CW
D001798:Blood Proteins / Q000737:chemistry* / Q000302:isolation & purification; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000201:enzymology; D003928:Diabetic Nephropathies / Q000097:blood* / Q000201:enzymology; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics
D001798:Blood Proteins; D020543:Proteome; D005979:Glutathione Peroxidase