Proteomics of renal disorders: Urinary proteome analysis by two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry [Review]

摘要

The proteomes of urinary samples from patients with different renal conditions were analysed by two-dimensional electrophoresis and MALDI-TOF technology. Samples from three different renal conditions, namely kidney failure, nephrotic syndrome and microalbuminuria, were included in the analysis. Apart from the presence of albumin, the profiles of protein spots found in these urine samples were quite distinct. While kidney failure patients showed predominantly low molecular weight proteins, the nephrotic syndrome patients showed an abundance of relatively high molecular weight proteins clustering in the acidic range of the 2-D gels. Two different protein spots from kidney failure patients, four from nephrotic syndrome patients and three from micro-albuminuria patients were identified by in-gel protease digestions and analysis of resulting peptides by MALDI-TOF. The proteins identified were albumin, alpha-1-antitrypsin, alpha-1-acid glycoprotein 2, Zn-alpha-2-glycoprotein and alpha-1-microglobulin. Among these, only one was common between the proteomes of renal failure and nephrotic syndrome patients. Among the limited proteins found in microalbuminuria patients, three were common with the proteome of nephrotic syndrome. Overall profiles were, however, quite different. Our study showed that urinary proteomes of different renal conditions were different and emphasized the potential of urinary proteome analysis to augment existing tools in the diagnosis of renal disorders.