Bioinformatics Analysis of Proteomic Profiles During the Process of Anti-Thy1 Nephritis

Abstract

-Thy1 nephritis is a well-established experimental mesangial proliferative nephritis model. Exploring the molecular mechanisms of pathophysiology in anti-Thy1 nephritis may elucidate the pathogeneses of mesangial proliferation. We examined the roles and acting mechanisms of differentially expressed proteins (DEPs) by bioinformatics analysis of glomeruli proteomic profiles during the course of anti-Thy1 nephritis. In total, 108 DEPs were found by two-dimensional fluorescence difference gel electrophoresis (2D-DIGE), and 40 DEPs were identified by matrix-assisted laser desorption ionization/time of flight and liquid chromatography-MS. DEPs were classified into five clusters (Clusters 1-5), according to their expression trends using Cluster 3.0 software, involved in regulating biological processes such as the stress response, cell proliferation, apoptosis, energy metabolism, transport, and the actin cytoskeleton. The expression patterns of ten DEPs, distributed across five clusters, including AKR1A1, AGAT, ATP6V1B2, HIBADH, MDH1, MPST, NIT2, PRDX6, PSMB7, and TPI1, were validated by Western blotting. Based on Western blotting and immunohistochemistry, we also found that the DEP FHL2, which was primarily expressed in the mesangial region, was downregulated on days 3 and 5, and up-regulated on day 10. In vitro, we found that FHL2 overexpression induced mesangial cell proliferation by increasing the number of Sphase cells and decreasing G2/M-phase cells, whereas inhibiting FHL2 had the opposite effect. This study explored novel DEPs and their expression patterns during anti-Thy1 nephritis, and elucidated FHL2's effect on mesangial cell proliferation. These results will contribute to our understanding of the pathogenesis of mesangial proliferation. Molecular & Cellular Proteomics 11: 10.1074/mcp.M111.008755, 1-13, 2012. Mesangial proliferative glomerulonephritis (MesPGN) 1 is the most common chronic kidney disease and is characterized by pathological changes in mesangial cell proliferation and extracellular matrix accumulation. As an important cause of end-stage renal disease, MesPGN has been a major focus of renal disease research. Examining the molecular mechanisms of MesPGN may elucidate its pathogenesis and thereby facilitate the development of clinical treatments. Animal models, such as rat anti-Thy1 nephritis, provide a useful tool to explore these mechanisms.