甲基化修饰对IgA肾病外周血B淋巴细胞Cosmc基因表达的调节作用

Effect of Methylation Modification on the Expression of Cosmc Gene in Peripheral B Lymphocyte of IgA Nephropathy Patients

目的探讨甲基化修饰对IgA肾病患者外周血B淋巴细胞Cosmc基因mRNA表达水平的影响。方法用抗凝管采集22例IgA肾病患者和20例健康体检者(正常对照)静脉血,采用磁珠分离外周血B淋巴细胞,以RPMI1640、脂多糖(LPS 12.5μg/mL)和5-氮杂胞苷(5-AZA 0.1、0.5和1.0μmol/L)处理72h。采用实时荧光RT-PCR的方法测定Cosmc表达水平。结果 IgA肾病患者外周血B淋巴细胞Cosmc基因mRNA表达水平低于正常对照(31.3%,P<0.05)。经RPMI1640培养基处理后IgA肾病患者Cosmc基因的表达升高(为处理前的219%,P<0.05),但LPS能逆转Cosmc基因的表达上调(降低至RPMI1640组的60%)。采用5-AZA进行去甲基化修饰后Cosmc基因表达上调(5-AZA 0.1、0.5、1.0μmol/L处理后Cosmc基因表达上升至RPMI1640组的67%、82%和103%)。结论以LPS为代表的外源性抑制介质通过甲基化修饰抑制了Cosmc基因的表达,而去甲基化修饰则能有效的逆转Cosmc基因受抑情况。5-AZA可能具有治疗IgA肾病的潜力。

Objective To investigate the effect of methylation modification on the mRNA expression of Cosmc gene in peripheral B lymphocytes from IgA nephropathy（IgAN）.Methods Biopsy identified 22 cases of IgAN patients and 20 cases of normal control were included.Peripheral B lymphocytes were isolated and were cultured with RPMI1640 medium,with LPS（12.5 μg/mL） as well as demethylation agent（5-AZA 0.1 μmol/L,0.5 μmol/L and 1.0 μmol/L） for 72 hours,respectively.Expression level of Cosmc gene was measured using real-time PCR.Results The mRNA expression level of Cosmc gene in IgAN patients was significantly lower than that of control（P0.05）.The Cosmc gene expression level increased dramatically after RPMI1640 treatment（P0.05）,however,LPS could apparently reverse this effect（P0.05）.De-methylation modification up regulated the Cosmc gene expression significantly（P0.05）.Conclusion De-methylation modification could effectively reverse the repressed Comsc gene mRNA expression caused by external suppressors.