Conclusion: Increasing the degradation of nucleosomes, reducing their immunogenicity, and preventing binding of nucleosome–IgG complexes in glomeruli together provide an alternative basis for the treatment of lupus nephritis.
Alterations in Wnt pathway activity in mouse serum and kidneys during lupus development. (Arthritis Rheum. 2011;63:513-522.)
Abstract
Objective: The canonical Wnt/β-catenin pathway was recently identified as a factor in the pathogenesis of several renal diseases. The aim of this study was to evaluate Wnt signaling activity during disease development in a murine model of lupus nephritis.
Methods: Wnt activity and Dkk-1 expression were serially assayed in the serum and kidneys of (NZB × NZW)F1 mice during progression of lupus nephritis. The effects of serum obtained from mice with lupus and serum-equivalent concentrations of Dkk-1 on mesangial cells were assessed in vitro.
Results: Gene expression analyses revealed increased canonical Wnt pathway activity in kidneys during development of lupus nephritis, paralleled by an increase in renal and serum levels of the Wnt inhibitor Dkk-1. Sera obtained from proteinuric-stage (NZB × NZW)F1 mice showed strong Wnt-inhibitory effects in vitro. Dkk-1 concentrations comparable to those observed in lupus-prone mice induced apoptosis in tubular and mesangial cells in vitro, whereas no such effect was seen for the range of concentrations observed in young prediseased mice and control BALB/c mice.
Conclusion: These data demonstrate that renal Wnt signaling activity is increased in lupus and is accompanied by an increase in renal and serum levels of Dkk-1. The Wnt pathway is involved in the turnover of extracellular matrix constituents and represents a potential mediator of the morphologic changes that occur within the glomerulus during the development of nephritis. Furthermore, increased levels of Dkk-1 serve as a potential proapoptotic stimulus in vitro and possibly in vivo and could be an important element in the initiation and progression of systemic and end-organ disease manifestations in systemic lupus erythematosus.
The NZM2410-derived lupus susceptibility locus Sle2c1 increases Th17 polarization and induces nephritis in fas-deficient mice. (Arthritis Rheum. 2011;63:764-774.)
Abstract
Objective: Sle2 is a lupus susceptibility locus that has been linked to glomerulonephritis in the NZM2410 mouse. By itself, Sle2 does not induce any autoimmune pathology but results in the accumulation of B-1a cells. This study was designed to assess the contribution of Sle2 to the pathogenesis of autoimmunity.
Methods: Sle2 or its subcongenic intervals (Sle2a, Sle2b, and Sle2c1) were bred to Fas-deficient B6.lpr mice. Lymphoid phenotypes, which were focused on T cells, were assessed by flow cytometry, and histopathologic changes were compared between cohorts of B6.Sle2.lpr congenic mice and B6.lpr mice of ages up to 6 months.
