背景:短链脂肪酸(SCFA),作为肠道微生物群和免疫系统之间的联系,据报道,通过调节T细胞分化在许多自身免疫性疾病中具有保护作用。自身反应性Th1和Th17细胞的致病作用以及Treg细胞在抗GBM疾病发病机制中的保护作用已得到充分证明。因此,本研究旨在探讨SCFAs在抗GBM疾病大鼠模型中的治疗作用。
方法:用肾源性T细胞表位α3127-148免疫Wistar京都大鼠,并以乙酸钠干预,构建实验性抗GBM病,丙酸钠,或者丁酸钠,从第0天到42天在饮用水中150mM。通过生化分析仪获取肾损伤,免疫荧光,和免疫组织化学。通过ELISA检测抗体应答。流式细胞术检测T细胞聚集和增殖。体外刺激人肾2(HK2)细胞,并通过定量实时PCR评估细胞因子。
结果:用乙酸钠处理,丙酸钠,或丁酸钠可改善抗GBM肾小球肾炎大鼠肾脏损害的严重程度。在丁酸钠治疗的大鼠中,尿蛋白,血清肌酐,和血尿素氮水平显着降低;肾小球中新月形成的百分比显着降低;肾脏显示IgG沉积减少,补体激活,T细胞,和巨噬细胞浸润以及抗抗α3(IV)NC1的循环抗体水平。丁酸钠的处理降低了α3127-148特异性T细胞活化,增加了Treg细胞分化和肠道有益菌菌群。它还减轻了炎症因子和补体处理的HK2细胞的损伤。
结论:SCFA治疗,尤其是丁酸,减轻大鼠模型的抗GBM肾炎,表明其在临床使用中的潜在治疗效果。
Short-chain fatty acids (SCFAs), as the link between gut microbiota and the immune system, had been reported to be protective in many autoimmune diseases by the modulation of T cell differentiation. The pathogenic role of autoreactive Th1 and Th17 cells and the protective role of Treg cells in the pathogenesis of anti-GBM disease have been fully demonstrated. Thus, the present study aimed to investigate the therapeutic effects of SCFAs in a rat model of anti-GBM disease.
Experimental anti-GBM disease was constructed by immunizing Wistar Kyoto rats with a nephrogenic T cell epitope α3127-148, and intervened by sodium acetate, sodium propionate, or sodium butyrate, 150 mM in the drinking water from day 0 to 42. Kidney injury was accessed by the biochemical analyzer, immunofluorescence, and immunohistochemistry. Antibody response was detected by ELISA. T cell clustering and proliferation were detected by flow cytometry. Human kidney 2 (HK2) cells were stimulated in vitro and cytokines were assessed by quantitative real-time PCR.
Treatment with sodium acetate, sodium propionate, or sodium butyrate ameliorated the severity of kidney impairment in rats with anti-GBM glomerulonephritis. In the sodium butyrate-treated rats, the urinary protein, serum creatinine, and blood urea nitrogen levels were significantly lower; the percentage of crescent formation in glomeruli was significantly reduced; and the kidneys showed reduced IgG deposition, complement activation, T cell, and macrophage infiltration as well as the level of circulating antibodies against anti-α3(IV)NC1. The treatment of sodium butyrate reduced the α3127-148-specific T cell activation and increased the Treg cells differentiation and the intestinal beneficial bacteria flora. It also alleviated the damage of HK2 cells treated with inflammatory factors and complement.
Treatment with SCFAs, especially butyrate, alleviated anti-GBM nephritis in rat model, indicating its potential therapeutic effects in clinical usage.