MicroRNA-29b contributes to DNA hypomethylation of CD4+T cells in systemic lupus erythematosus by indirectly targeting DNA methyltransferase 1
MicroRNA-29b contributes to DNA hypomethylation of CD4+T cells in systemic lupus erythematosus by indirectly targeting DNA methyltransferase 1
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DOI：
10.1016/j.jdermsci.2012.10.011
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发表时间：
2013-01-01
影响因子：
4.6
通讯作者：
Xu, Jinhua
中科院分区：
文献类型：
--
作者：
Qin, Haihong;Zhu, Xiaohua;Xu, Jinhua
背景：系统性红斑狼疮（SLE）中DNA低甲基化的机制尚未完全阐明。最近的研究表明miR-29 b可以通过靶向DNA甲基化机制来调控DNA甲基化。然而，miR-29 b在SLE T细胞异常DNA低甲基化中的作用仍不清楚。目的：本研究探讨miR-29 b是否调控狼疮CD 4 + T细胞DNA甲基化。方法：采用定量聚合酶链反应（OCR）分析miR-29 b的表达。分别采用qPCR、Western-blotting和流式细胞术检测Sp1、DNMT 1、CD 11 a和CD 70 mRNA和蛋白水平。通过Methyflash（TM）DNA甲基化定量试剂盒评价总体DNA甲基化水平。结果：SLE患者miR-29 b的表达水平较正常对照组明显上调，且其过表达程度分别与SP1和DNMT 1蛋白表达水平呈负相关。miR-29 b的过表达导致sp1和DNMT 1的表达显著降低。结论：miR-29 b通过靶向调节T细胞中的sp1，负性调节DNMT 1的表达，从而抑制SLE患者CD 4 + T细胞中miR-29 b的表达。miR-29 b的过表达有助于SLE中DNMT 1水平的降低，从而导致DNA低甲基化。这一发现为治疗干预提供了潜在的新策略。(C)2012年日本皮肤病研究学会。由Elsevier爱尔兰有限公司出版。保留所有权利。
Background: The mechanism of DNA hypomethylation in systemic lupus erythematosus (SLE) has not been fully elucidated. Recent studies showed that miR-29b could regulate DNA methylation by targeting the DNA methylation machinery. However, the role of miR-29b in T cell aberrant DNA hypomethylation of SLE still remains unclear. Objective: In this study, we asked whether miR-29b regulate DNA methylation in lupus CD4+ T cells.Methods: The miR-29b expression was analyzed by quantitative polymerase chain reaction (OCR). Sp1, DNMT1, CD11a and CD70 mRNA and protein levels were determined by qPCR, Western-blotting and flow cytometry, respectively. The global DNA methylation levels were evaluated by the Methyflash (TM) DNA Methylation Quantification Kit. CD11a and CD70 promoter methyaltion levels were detected by bisulfate modification and methylation-sensitive high resolution melting analysis.Results: In SLE patients, the miR-29b levels were up-regulated as compared to healthy donors and its degree of overexpression was negatively correlated with sp1 and DNMT1 protein levels, respectively. Overexpression of miR-29b resulted in significant reduction of sp1 and DNMT1 expression. Further analysis demonstrated that overexpression of miR-29b in CD4+ T cells from healthy donors led to the DNA hypomethylation and up-regulation of genes encoding CD11a and CD70, and inhibition of miR-29b expression in CD4+ T cells from patients with lupus caused reverse effects.Conclusion: Our study suggests that miR-29b negatively regulates DNMT1 expression by targeting sp1 in T cells. The overexpression of miR-29b contributes to the reduction of DNMT1 levels and thereby DNA hypomethylation in SLE. This finding provides potential novel strategies for therapeutic interventions. (C) 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.