Sublytic C5b-9 induces glomerular mesangial cell proliferation via ERK1/2-dependent SOX9 phosphorylation and acetylation by enhancing Cyclin D1 in rat Thy-1 nephritis

Abstract

Glomerular mesangial cell (GMC) proliferation is a histopathological alteration in human mesangioproliferative glomerulonephritis (MsPGN) or in animal models of MsPGN, e.g., the rat Thy‐1 nephritis (Thy-1N) model. Although sublytic C5b-9 assembly on the GMC membrane can trigger cell proliferation, the mechanisms are still undefined. We found that sublytic C5b-9-induced rat GMC proliferation was driven by extracellular signal‐regulated kinase 1/2 (ERK1/2), sry-related HMG-box 9 (SOX9), and Cyclin D1. Here, ERK1/2 phosphorylation was a result of the calcium influx-PKC-α-Raf-MEK1/2 axis activated by sublytic C5b-9, and Cyclin D1 gene transcription was enhanced by ERK1/2-dependent SOX9 binding to the Cyclin D1 promoter (−582 to −238 nt). In addition, ERK1/2 not only interacted with SOX9 in the cell nucleus to mediate its phosphorylation at serine residues 64 (a new site identified by mass spectrometry) and 181 (a known site), but also indirectly induced SOX9 acetylation by elevating the expression of general control non-repressed protein 5 (GCN5), which together resulted in Cyclin D1 synthesis and GMC proliferation. Moreover, our in vivo experiments confirmed that silencing these genes ameliorated the lesions of Thy‐1N rats and reduced SOX9 phosphorylation, acetylation and Cyclin D1 expression. Furthermore, the renal tissue sections of MsPGN patients also showed higher phosphorylation or expression of ERK1/2, SOX9, and Cyclin D1. In summary, these findings suggest that sublytic C5b-9-induced GMC proliferation in rat Thy-1N requires SOX9 phosphorylation and acetylation via enhanced Cyclin D1 gene transcription, which may provide a new insight into human MsPGN pathogenesis.

Global-feature of autoimmune glomerulonephritis using proteomic analysis of laser capture microdissected glomeruli

“…The protein abundance of MAPK3 (ERK1) in the four GNs were remarkable downregulated. It is known that the mis-localization and signaling imbalances of MAPKs ERK1/2 are closely correlated with cancer to inflammatory disease and may have a significant impact on the outcome of immune kidney diseases (14)(15)(16). The specific regulation to ERK1/2 activity appears to significantly ameliorate albuminuria and glomerulosclerosis in immune renal disease (17).…”

“…In podocytes, sublytic C5b-9 may activates downstream pathways including protein kinases, reactive oxygen species, growth factors/gene transcription, endoplasmic reticulum stress, and the ubiquitin-proteasome system, and further disrupt the integrity of the cytoskeleton and slit diaphragm, causing the appearance of massive proteinuria ( 31 , 32 ). In nephritis rat models, sublytic C5b-9 induces glomerular mesangial cell proliferation via activation of ERK1/2, SOX9, and Cyclin D1 ( 16 ). The expression of C5 was indeed upregulated in LN, IgAN, and MN groups, despite cannot distinguish the abundance of C5a and C5b from C5 is our study.…”

Sublytic C5b-9 Induces CCL3/4 Production and Macrophage Accumulation in Thy-1N Rats via PKC-α/p65/IRF-8 Axis

“…Many studies have demonstrated that complement system activation (i.e. C5b-9 formation), Mφ infiltration, pro-inflammatory cytokine and chemokine production all contribute to the renal pathological changes of MsPGN 1 - 3 , 6 , 34 - 36 . As a well-established animal model of MsPGN, Thy-1N pathogenesis is dependent on complement particularly sublytic C5b-9 8 - 12 .…”

“…Mesangioproliferative glomerulonephritis (MsPGN) is a chronic kidney disease in human 1 - 3 . The mechanism of MsPGN involves in complement activation, inflammatory cell (e.g.…”

Modulation of IL-6 Expression by KLF4-Mediated Transactivation and PCAF-Mediated Acetylation in Sublytic C5b-9-Induced Rat Glomerular Mesangial Cells

“…Renal inflammation, glomerular mesangial cell (GMC) proliferation, and matrix overproduction are key features of human mesangial proliferative glomerulonephritis (MsPGN), such as IgA nephropathy (1)(2)(3). Thy-1 nephritis (Thy-1N) as a popular experimental model for MsPGN is induced in the rat by injection of antibody to Thy-1, triggering activation of the complement system and subsequent formation of C5b-9 on the surface of GMC membranes (4)(5)(6). Previous studies have demonstrated that renal pathologic changes in Thy-1N rats are complement-dependent, especially sublytic C5b-9-dependent (7)(8)(9)(10).…”