机械应力下环状RNA分子circ_002354靶向miR-470-5p调控RyR2参与心肌肥厚的分子机制

The sarcoplasmic reticulum calcium channel RyR2 promotes cardiac hypertrophy induced by pressure overload, however, the mechanism of RyR2 upstream regulationunder pressure overload remains to be elucidated. Our previous study found that the expression of circ_002354, a circular RNA, was increased in cardiac hypertrophy and the expression of RyR2 decreased after knockdown circ_002354. Bioinformatics found that miR-470-5p could target circ_002354 and RyR2. It is speculated that circ_002354 may affect myocardial hypertrophy by inhibited miR-470-5p to regulate RyR2. We will investigate the expression of circ_002354 on cardiac hypertrophy through the model of cardiac hypertrophy of in vivo and in vitro models, and study the effects of circ_002354 on cardiac hypertrophy by in vitro/in vivo knockdown/overexpression of circ_002354. Further investigate the effect and mechanism of circ_002354 on RyR2 though miR-470-5p by using bioinformatics, knockdown model, RIP and dual-luciferase reporter assay system; subsequently propose to further use our already constructed RyR2+/- mice to verify whether circ_002354 affects cardiac hypertrophy by regulating RyR2. This project is expected to further reveal the regulatory mechanism of circRNA on the key signals of cardiac hypertrophy.

肌质网钙离子释放通道RyR2促进压力超负荷诱导的心肌肥厚，然而其上游调控机制仍有待阐明。我们前期研究发现压力超负荷时环状RNA分子circ_002354表达上调，干扰circ_002354后RyR2表达降低。生信分析发现miR-470-5p可以靶向结合circ_002354和RyR2 3’UTR。据此推测circ_002354靶向miR-470-5p上调RyR2影响心肌肥厚。首先拟验证circ_002354的生物学特征；其次通过体内外干扰/过表达模型，研究其对RyR2及心肌肥厚的影响；然后使用敲减模型、RIP和Dual-Luciferase等手段，明确circ_002354通过miR-470-5p对RyR2的调控作用及机制；最后运用RyR2+/-小鼠从在体和离体两方面对circ_002354调控RyR2促进心肌肥厚进行验证。本项目有望揭示circRNA对心肌肥厚关键信号的调控机制。

肌质网钙离子释放通道RyR2促进压力超负荷诱导的心肌肥厚，然而其上游调控机制仍有待阐明。我们研究发现环状RNA分子mmu_circ_002354主要表达在细胞质中，压力超负荷时表达上调，干扰mmu_circ_002354后RyR2表达降低，心肌肥厚程度减缓，暗示mmu_circ_002354调控RyR2进而参与心肌肥厚。生信分析发现miR-470-5p可以靶向结合mmu_circ_002354和RyR2 3’UTR，随后通过RIP和过表达miR-470-5p明确mmu_circ_002354 与 miR-470-5p 直接相互作用，表明mmu_circ_002354通过吸附miR-470-5p的方式调控RyR2。使用RyR2+/-小鼠在体内外建立心肌肥厚模型，过表达mmu_circ_002354无法加重心肌肥厚，进一步说明mmu_circ_002354通过调控RyR2影响心肌肥厚。此外，我们使用数据库高通量分析人、大鼠和小鼠的心脏circRNA的异同及其在心肌肥大和心衰中的差异表达，随后对人心衰的差异circRNA构建circRNA-miRNA-mRNA调控网络，为进一步将mmu_circ_002354的研究成果转化到人心血管病奠定基础。本项目有望揭示circRNA对心肌肥厚关键信号的调控机制。本项目目前已发表标注本基金号的SCI文章5篇，接收待发表1篇，培养博士研究生3名，硕士研究生2名。