Differential proteomic analysis of renal tissue in mesangial proliferative glomerulonephritis using iTRAQ technology

Mesangial proliferative glomerulonephritis (MePGN) is characterized by excessive mesangial cell proliferation and mesangial matrix expansion, which lead to glomerular sclerosis and obliteration and, in turn, to deteriorating renal function. To identify and quantify the total proteins in renal tissues of MePGN patients, we used isobaric tags for relative and absolute quantification (iTRAQ) technology, and then looked for differentially expressed proteome profiles in MePGN patients.

Eight-plex iTRAQ coupled with multiple chromatographic fractionation and tandem mass spectrometry was used to analyze total proteins in renal tissues of MePGN patients. Proteins were identified using Mascot, compared to show any differential expression.

Among 512 distinct proteins identified, 113 proteins were up-regulated or down-regulated with a onefold or more alteration in levels across groups. Among of them, there was significant variation in our present iTRAQ study, which contains lamin A, actin, profilin-1, annexin-A1 and A2 up-regulated, and antiquitin and aldolase B down-regulated.

iTRAQ-based quantitative proteomic technology is efficiently applicable for protein identification and relative quantitation of proteomes of renal tissue. Differentially expressed proteome profiles of MePGN patients are determined. Further investigation of the molecular mechanism of the involved proteins may help to better understand the pathogenesis of MePGN and to discover novel biomarker candidates, which may enable the development of new approaches to diagnosis of MePGN.