大黄素抑制IgG型抗双链DNA抗体诱导的系膜细胞表型转化的研究

Effect of emodin on phenotype transformation of mesangial cells induced by IgG subtype of anti-dsD-NA antibodies

目的探讨大黄素对IgG型抗双链DNA(dsDNA)抗体诱导的大鼠系膜细胞(MCs)表型转化的抑制作用。方法利用马疫锥虫动基体DNA诱导大鼠产生IgG型抗dsDNA抗体,小牛胸腺DNA纤维素层析法提纯抗体。体外培养正常MCs(空白组),或在培养上清中分别加入IgG型抗dsDNA抗体、25 mg/L大黄素(对照组),或同时加IgG型抗dsDNA抗体与大黄素(实验组),检测MCs合成转化生长因子-β_1(TGF-β_1)、α-平滑肌肌动蛋白(α-SMA)等水平,并在透视电镜下观察细胞显微结构的变化。结果与空白组比较,抗体对照组合成TGF-β_1等水平明显升高(P<0.05),并出现肌成纤维细胞样结构变化;而大黄素对照组的上述指标下降(P<0.05),且细胞显微结构基本正常。与抗体对照组比较,实验组合成TGF-β_1等水平降低,细胞显微结构大致正常。结论抑制IgG型抗dsDNA抗体诱导的系膜细胞表型转化可能是大黄素治疗狼疮肾炎的药理机制之一。

Objective To study the effect of emodin on the phenotype transformation of mesangial cells （MCs） cultured in vitro induced by IgG subtype of anti-double strands DNA （dsDNA） antibodies. Methods The purified kinetoplast DNA （kDNA） of Trypanosoma Equiperdum was subcutaneously injected into normal Wistar rats to establish animal models. The sera of these rats included IgG subtype of anti-dsDNA antibodies. The purified IgG antibodies were isolated from rat sera bovine thymus （CT） DNA-cellulose. The specificity of the antibodies to CT was determined by ELISA kit. The normal rat MCs were cultured in vitro, or co-cultured with IgG type anti-dsDNA antibodies, 25 mg/L emodin or a combination of them respectively. The levels of TGF-β1, α-smooth muscle actin （α-SMA） and laminin expressed by MCs were detected by ELISA or Western blotting. Their proliferations were measured by MTT assay. The electronic microcopy was used to observe the morphological changes of MCs. Results Compared with normal MCs, the group co-cultured with anti-dsDNA antibodies showed higher levels of TGF-β1, α-SMA and lami.nin （P〈0.05） and evident morphologic changes of myofibroblast including elongated shape and the appearance of smooth muscle actin under the electron-microscope. The MCs cultured with emodin had the reverse effects （P〈0.05）. The above parameters of the MCs group cultured with both emodin and antidsDNA antibodies were lower than that of the group of simple IgG antibodies （P〈0.05）. Conclusion The IgG subtype of anti-dsDNA antibodies can induce phenotype transformation of MCs in vitro, that may be inhibited by emodin.