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Abstract: Sinomenine has been used to treat autoimmune diseases for centuries. However, the mechanism underlying its therapeutic effects remains unknown. Increasing recognition of the importance of the Th1/Th2 imbalance in nephritis has raised the questions of whether there is a Th1/Th2 imbalance in patients with mesangial proliferative nephritis (MsPGN) and whether sinomenine can modulate the Th1/Th2 imbalance. In this study, 25 MsPGN patients were treated with sinomenine and followed for 3 months. The expression of T-bet and GATA-3 mRNA in peripheral blood mononuclear cells (PBMCs) and the serum levels of interferon-γ (IFN-γ), interleukin (IL)-4, and IL-10 were studied at month 0, month 1, and month 3. The intra-renal expression of T-bet and GATA-3 was studied via immunohistochemistry. Results reveal that PBMCs from MsPGN patients expressed high levels of T-bet mRNA and low levels of GATA-3 mRNA, and the T-bet/GATA-3 ratio in MsPGN patients was significantly higher than that in healthy donors. Meanwhile, MsPGN patients were found to have simultaneously elevated IFN-γ values and decreased IL-10 values. Immunohistochemistry revealed increased T-bet and decreased GATA-3 expression in renal tissues from MsPGN patients. Moreover, sinomenine was found to cause a decrease in T-bet mRNA expression, resulting in a drop in the T-bet/GATA-3 ratio. Sinomenine was also found to elicit a decrease in the serum levels of IFN-γ. These results suggest that a shift toward the Th1 pathway of Th cell activation occurs in MsPGN patients, and that sinomenine has the potential to counter this shift in the Th1/Th2 balance and thereby produce therapeutic effects. [Copyright &y& Elsevier]

Abstract: The co-inhibitory molecule B7-H1 has been broadly detectable on human inflammatory renal tubular epithelial cells (TECs) and is proposed to limit tubular damage through down-regulation of tubulointerstitial infiltration T cell activation. Nevertheless, factors that initiate B7-H1 expression on TECs remain unclarified. The terminal complement complex C5b-9, which deposits diffusely on tubules and glomerules of diseased kidneys, is now recognized as a mediator that triggers cellular activation rather than inducing cell death. Whether the up-regulation of B7-H1 on tubules is also induced by C5b-9 is uncertain. Here, after assembling functional sublytic C5b-9 on the membranes of TECs based on purified complement components, we found that B7-H1 gene transcription and protein synthesis was enhanced by C5b-9. Promoter constructs in a luciferase assay, site-directed mutagenesis and laser scanning confocal microscopy assay (LSCM) revealed that the transcription factor NF-κB is primarily responsible for C5b-9-mediated B7-H1 expression. To further detect the physiologic function of B7-H1, triggering B7-H1 with its agonist mAb (clone 5H1) profoundly enhanced Fas expression on C5b-9-treated TECs and thus induced TEC apoptosis. Interestingly, pretreatment of TECs with Fas blocking antibodies prevented this effect. Our results propose that C5b-9 regulates tubular pathogenesis in glomerulonephritis or other renal autoimmune diseases, possibly through enhances cell apoptosis mediated by B7-H1 signals, in addition to it directly promotes tubular damage. [Copyright &y& Elsevier]

Abstract: Previous studies have shown that sinomenine possesses potent immunoregulatory properties. However, little is known about its exact mechanisms of action. Increasing recognition of the importance of renal tubular epithelial cells (TECs) in renal diseases raises the question whether sinomenine can regulate TEC activity. In this study, cultured human TECs were exposed to proinflammatory factors interferon-γ (IFN-γ) and tumor necrotic factor-α (TNF-α) in presence or absence of sinomenine for 72 h, followed by analysis of surface expression of costimulatory molecules. Flow cytometric analysis revealed that various costimulatory molecules were expressed on TECs and that they were significantly up-regulated by the simulation of IFN-γ and TNF-α. However, sinomenine especially down-regulated B7-H1 and B7-DC expression on TECs at both mRNA and protein levels. Moreover, the significant damping effect of sinomenine on B7-H1 and B7-DC signals could promote IL-2 and IFN-γ production by co-cultured CD4+ T cell. Our results indicated that sinomenine could regulate TECs activity via B7-H1 and B7-DC, in addition to previously reported its effects on some pro-inflammatory factors production by macrophages and peripheral blood mononuclear cells. [Copyright &y& Elsevier]