MiR-212与MeCP2相互调控在早产子宫平滑肌收缩机制中的作用

Preterm birth leads to perinatal mortality and long-term prognosis, which is a heavy burden to society and family. Previous studies suggested that premature uterine smooth muscle contraction have specific regulatory mechanisms. We first found uterine smooth muscle (UtSM) of patients in preterm labor were expressed high levels of miR-212, in vitro overexpression of miR-212 causes UtSM cells contraction; we also first discovered in uterine smooth muscle the level of MeCP2(methylation in regulatory pretein 2), miR-212 target gene, significantly decreased in preterm patients. In vitro Inhibiting MeCP2 Expression by RNA Interference in UtSM cells can cause UtSM cells contraction. Therefore, this project is divided into three phases: in vitro cellular study, in vivo preterm animal model, knockout mice. The expression of miR-212 after activation/inhibition of NF-kB pathway and their likely signal transduction pathway; the mutually modulated relationships between miR-212 and MeCP2; and analysis MeCP2 downstream a series of molecular cascade reaction protein expression and regulation of UtSM cells contraction response capabilities. Aim to confirm: preterm uterine smooth muscle contraction via intracellular specific regulatory interactions: NF-kB activation which stimulate miR-212 overexpression and inhibit MeCP2. It is important to provide new ideas for the study of the pathogenesis of preterm labor. Provide clues for further molecular intervention in the future.

早产导致围产儿死亡且影响远期预后，对社会和家庭造成沉重负担。前期研究发现早产子宫平滑肌收缩调控机制存在特异性，首次发现早产临产患者子宫平滑肌细胞中存在miR-212表达且存在表达差异，体外上调miR-212引起子宫平滑肌细胞收缩；还首次发现miR-212的靶基因甲基化调节蛋白MeCP2在早产临产患者子宫平滑肌细胞中显著下降，体外siRNA抑制MeCP2也能引起子宫平滑肌收缩。因此本项目拟通过体外细胞水平及早产鼠模型、基因敲除小鼠三个层面研究NF-kB通路对miR-212影响及可能的分子机制；miR-212与靶基因mecp2之间的相互作用; MeCP2调控子宫平滑肌收缩的分子机制。目的在于证实：细胞内NF-kB通路活化，刺激miR-212过表达，与MeCP2相互作用特异性调控早产子宫平滑肌收缩。这对早产发病机制有重要意义；为未来进一步分子干预早产提供线索。

早产造成围产儿死亡且影响远期预后，对社会和家庭造成沉重的负担。目前研究认为 miRNA 调节在早产发病中有重要作用，但涉及 miRNA与早产子宫收缩的分子机制研究很少。.本课题拟通过体外细胞水平及早产鼠模型、基因敲除小鼠三个层面研究NF-kB通路对miR-212影响及可能的分子机制；miR-212与靶基因mecp2之间的相互作用; MeCP2调控子宫平滑肌收缩的分子机制。.研究发现.（1）miRNA-212-3p靶向MeCP2调控早产子宫平滑肌细胞异常收缩.体外研究发现炎症因子可以调控人类平滑肌细胞中miRNA-212-3p的表达；ICR小鼠LPS诱导早产模型建立，发现miRNA-212-3p与收缩相关蛋白在ICR小鼠LPS诱导早产模型的子宫平滑肌中表达失常；miRNA-212-3p是促进子宫平滑肌细胞收缩的分子表达；MeCP2作为miRNA-212-3p靶向分子也可以调控子宫平滑肌细胞收缩功能。做MeCP2过表达和干扰调控的RNAsequence研究分析，并验证发现MeCP2引起子宫平滑肌细胞胆固醇代谢酶表达差异。.（2）血清miRNAs作为早产的生物学标志物探索.按照准入及排除标准一共募集到74例孕妇自愿加入研究，其中包括42例先兆早产的孕妇（包括15例自发性早产、27例未足月胎膜早破）和32例无产兆的孕晚期产妇。发现循环miRNA-26b-5p，miRNA-4746-3p，miRNA-936异常升高与自发性早产和未足月胎膜早破有关。通过生物信息学分析循环异常表达的miRNA的可能作用靶点分析。miR-939, miR-4746-3p和miR-26b-5p靶向作用于细胞周期调控，miRNA介导的转录后调控和心脏肌细胞的细胞凋亡等生物学过程。.证实： IL-1β、IL-6和PMA刺激细胞内miR-212过表达，与MeCP2相互作用特异性调控早产子宫平滑肌收缩。上述研究为早产发病机制研究提供新的思路。为未来寻找更有效的早产干预手段奠定基础。