MicroRNA30b/125b/133a1逆转心脏瓣膜成肌骨细胞分化阻止瓣膜纤维钙化的作用及机制研究

Recent studies have shown that valvular fibrocalcification occurs through highly regulated molecular processes characterized by transdifferentiation from valve interstitial cells to myofibroblasts and/or osteoblasts(myo/osteoblasts), and reversal of this process is expected to be an effective treatment for CAVD. In our previous study, we showed that microRNA30b/125b/133a1 could decrease the expression of phenotypic transcription factors and phenotypic protein of myo/osteoblasts, suggesting that microRNA30b/125b/133a1 may be phenotypic regulatory factors critical for myo/osteoblast differentiation. To further assess the potential value of microRNA30b/125b/133a1, we set out to examine the reversal effect of microRNA30b/125b/133a1 on myo/osteoblasts at various developmental stages , and to clarify the molecular mechanisms of microRNA30b/125b/133a1-mediated phenotypic transdifferentiation from myo/osteoblasts to valve interstitial cells. In addition, we will further examine the effect of phenotypic reversal of myo/osteoblasts on the regression of CAVD in vivo. Conceivably, elucidation of the effect and molecular pathways involved in the phenotypic transdifferentiation of myo/osteoblasts will provide important clues either for the development of novel prevention therapies in CAVD, or for the microRNAs-regulated adult cells direct transdifferentiation.

新近研究显示，钙化性主动脉瓣疾病(CAVD)瓣膜纤维钙化的核心为间质细胞向成肌骨细胞转分化,而将不同分化阶段的成肌骨细胞重新逆转为间质细胞有望成为CAVD防治的突破口。前期,我们证实microRNA30b/125b/133a1能抑制成肌骨细胞表型转录因子和表型蛋白的表达，提示其是启闭成肌骨细胞分化的关键表型调控因子。基于此，本项目旨在明确该组合对不同分化阶段的成肌骨细胞表型的逆转作用；同时，采用多种分子生物学技术逐步分析此组合启动和维持成肌骨细胞表型逆转的分子调控机制；此外我们还将在体内模型上验证成肌骨细胞表型逆转分化对瓣膜纤维钙化进展的延缓作用。总之，本项目的实施，不仅能为"microRNA调控成体细胞间直接转分化"这一细胞学领域的核心命题提供新的研究证据，而且对CAVD的防治提供新思路，具有一定的理论指导意义。

背景：microRNA30b/125b/133a1能抑制成肌骨细胞表型转录因子和表型蛋白的表达，是启闭成肌骨细胞分化的关键表型调控因子,但其具体分子调控机制有待明确。.目标及主要内容：明确此基因对不同分化阶段的成肌骨细胞表型的逆转作用；同时，采用多种分子生物学技术逐步分析其启动和维持成肌骨细胞表型逆转的分子调控机制；此外通过在体模型验证microRNA30b/125b/133a1在瓣膜纤维钙化早期的表达。重要结果及关键数据：我们运用BMP-2成功构建瓣膜钙化研究的体外模型，在此基础上行qPCR显示microRNA30b/125b/133a1在钙化培养基中表达下调，并通过在体模型验证。进而对这三个基因的功能进行研究，结果显示microRNA30b/125b/133a1分别通过直接的转录后抑制作用于Runx2、Osterix和SP1从而阻断了瓣膜间质细胞向成骨细胞转分化。科学意义：明确microRNA30b/125b/133a1对Runx2、Osterix和SP1的直接转录调控作用，证实其表达失调参与瓣膜间质细胞成骨分化,为今后CAVD的生物治疗提供理论依据及潜在靶点。