特定lncRNA在宫内生长受限引起心脏发育不成熟中的作用与调控机制

The negative intrauterine environment often results in fetal growth restriction (FGR) via causing epigenetic changes, leads to heart immaturity and increased risk of cardiac diseases in adulthood. But the functions and mechanisms of novel epigenetic member long non-coding RNA (lncRNA) in this process remain unexplored. Our recent study found that FGR could result in heart immaturity of offspring and decreased expression of lncRNA_CMAT in neonatal heart. Further study found that lncRNA_CMAT, specifically high-expressed in the heart, was significantly up-regulated during the heart development. Our preliminary data also showed that the expression level of lncRNA_CMAT exhibited significant difference in immature, neonatal, and adult cardiomyocytes, suggested that lncRNA_CMAT might be involved in the transcriptional regulation of cardiomyocytes maturation. Therefore, this project tried to systematically research on the molecular and epigenetic mechanisms of lncRNA_CMAT involved in the cardiomyocytes maturation with molecular techniques such as RNA-seq, RNA pull-down, RIP and ChIP. Furthermore, we would apply lncRNA into FGR model to determine whether lncRNA_CMAT could rescue the heart immaturity of FGR mice. Our research is not only conducive to develop a better understanding of lncRNA-involved regulatory network in the cardiomyocytes maturation, also provides more molecular cues and theoretical basis for the lncRNA-based therapy to FGR caused cardiac disease.

宫内不良环境常会通过改变表观遗传修饰引发胎儿生长受限（FGR），继而导致心脏发育不成熟，并增加罹患心脏疾病的风险，而表观调控新成员长链非编码RNA（lncRNA）在这一过程中的作用研究尚未见报道。我们前期研究显示FGR会造成子鼠心脏发育不成熟，且发现在心脏发育成熟过程中表达显著上调的lncRNA_CMAT在FGR子鼠心脏中显著低表达。已有结果还显示lncRNA_CMAT的表达水平与心肌细胞成熟度呈正相关。为此，本项目拟利用RNA-seq、RNA pull-down、RIP、ChIP等技术，研究lncRNA_CMAT调节心肌细胞成熟的分子和表观遗传机制，并将其介入FGR小鼠模型，进一步研究lncRNA_CMAT能否挽回FGR引起的心脏发育不成熟。本项目的研究将有助于理解心肌成熟中lncRNA参与的调控网络，也为以lncRNA作为靶标干预FGR引发的心脏疾病提供更多分子线索和理论基础。

胎儿生长受限导致罹患心脏疾病风险升高，但这一类胎源性成年心脏疾病的机理研究仍是当今该领域的研究难点，而ES细胞体外培养和定向心肌分化体系的成功构建极大促成了体外研究心脏器官的发生发育等生理和病理过程，将更有助于理解心肌细胞分化和心脏发育的分子机制、同时认识心脏疾病特别是胎源性心脏疾病的发生机理等。目前，对于心肌细胞分化和心脏发育成熟过程中是否还存在其他重要因素参与调控该过程的核心网络，并且如何从分子水平影响心肌分化和心脏发育成熟过程还有待更多的研究。LincRNA已被公认在调控ES细胞的命运中具有关键作用。但是到目前为止，绝大多数lincRNA的功能和作用机理仍然是未知的，有待进一步探究。在本项目执行期间，不仅顺利完成了项目任务书既定计划和任务，并在多个方面取得了重要的研究工作进展，具体成果总结如下：1）首次发现了lincRNA1405联合转录因子和表观修饰子调控心肌分化和心脏发育的重要表观遗传机制，同时鉴定发现了lincRNA 1281上的m6A修饰具有维持多能干细胞特性和合适心肌分化潜能的关键作用，拓展了对“RNA表观遗传”领域的认知；2）发现了lncRNA NORAD通过阻碍促生存因子FUBP1入核，从而调控细胞凋亡发生，还揭示了lncRNA LincU能通过介导ERK信号活性调控方式，维持ES细胞原始态全能性的重要机制；3）首次揭示了组蛋白修饰阅读蛋白TRIM66的特异性组蛋白修饰识别模式，并阐明了TRIM66在ES细胞的DNA损伤修复中的关键中介作用，还首次揭示辅助因子Sin3a可通过联合DNA羟甲基化酶Tet1形成转录激活机器，调控ES细胞的分化全能性，提出了Sin3a结合特定表观修饰分子促进基因转录表达的崭新模式。