Abstract：
Persistent and intense uterine contraction is a risk factor for preterm labor. We previously found that methyl-CpG-binding protein 2 (MeCP2), as a target of infection-related microRNA miR-212-3p, may play an inhibitory role in regulating myometrium contraction. However, the molecular mechanisms by which MeCP2 regulates myometrial contraction are still unknown. In this study, we found that MeCP2 protein expression was lower in myometrial specimens obtained from preterm labor cases, compared to those obtained from term labor cases. Herein, using RNA sequence analysis of global gene expression in human uterine smooth muscle cells (HUSMCs) following siMeCP2, we show that MeCP2 silencing caused dysregulation of the cholesterol metabolism pathway. Notably, MeCP2 silencing resulted in the upregulation of CYP27A1, the key enzyme involved in regulating cholesterol homeostasis, in HUSMCs. Methylation-specific PCR, chromatin immunoprecipitation, and dual luciferase reporter gene technology indicated that MeCP2 could bind to the methylated CYP27A1 promoter region and repress its transcription. Administration of siCYP27A1 in a lipopolysaccharide (LPS)-induced preterm labor mouse model delayed the onset of preterm labor. Human preterm myometrium and the LPS-induced preterm labor mouse model both showed lower expression of MeCP2 and increased expression of CYP27A1. These results demonstrated that aberrant upregulation of CYP27A1 induced by MeCP2 silencing is one of the mechanisms facilitating inappropriate myometrial contraction. CYP27A1 could be exploited as a novel therapeutic target for preterm birth.
摘要：
持续和强烈的子宫收缩是早产的危险因素。我们以前发现甲基-CpG结合蛋白2（MeCP2），作为感染相关微小RNAmiR-212-3p的靶标，可能在调节子宫肌层收缩中起抑制作用。然而,MeCP2调节子宫肌层收缩的分子机制尚不清楚.在这项研究中,我们发现MeCP2蛋白在早产病例中获得的子宫肌层标本中表达较低，与从足月劳动案件中获得的相比。在这里，使用siMeCP2后人类子宫平滑肌细胞（HUSMCs）中整体基因表达的RNA序列分析，我们表明MeCP2沉默导致胆固醇代谢途径失调。值得注意的是,MeCP2沉默导致CYP27A1上调,CYP27A1是调节胆固醇稳态的关键酶,在HUSMC中。甲基化特异性PCR（MSP），染色质免疫沉淀（ChIP）和双荧光素酶报告基因技术表明，MeCP2可以结合甲基化的CYP27A1启动子区域并抑制其转录。在LPS诱导的早产小鼠模型中施用siCYP27A1延迟了早产的开始。人早产子宫肌层和LPS诱导的早产小鼠模型均显示MeCP2表达降低和CYP27A1表达增加。这些结果表明，MeCP2沉默诱导的CYP27A1异常上调是促进子宫肌层不适当收缩的机制之一。CYP27A1可作为早产的新治疗靶点。
