NSD2促进circ-Cmss1诱发的HuR核质易位在心室重构中的作用及分子机制

circRNA regulates myocardial apoptosis, necrosis, proliferation and regeneration by combining with RNA binding protein. Based on that the circ-Cmss1 whose parental gene is Cmss1 that binds to Human antigen R (HuR) and regulates ventricular remodeling was identified via NSD2 expression changes, we hypothesized that the circ-Cmss1 expression is up-regulated due to the H3K36me2 of Cmss1 promoter mediated by NSD2, which regulates ventricular remodeling by means of binding to HuR and inducing its nuclear-cytoplasmic shutting. The project will focus on NSD2→the H3K36me2 of Cmss1 promoter→circ-Cmss1 and make HuR as the entry point in the model of cardiac hypertrophy, based on the result of Cmss1 raising circ-Cmss1, Epigenetic research methods will be used to elaborated the mechanism of the circ-Cmss1 up-regulation owing to Cmss1 transcription driven by NSD2-mediated H3K36me2. RNA pull-down and RIP combined with FISH to explore the circ-Cmss1-HuR interaction at the subcellular level, which will contribute to demonstrated the mechanism of circ-Cmss1 activating HuR from its difference expression between nucleus and cytoplasm, NSD2 promote circ-Cmss1-induced HuR nuclear-cytoplasmic shutting will been consolidated in order to achieve ventricular remodeling individualized treatment.

circRNA可与RBP结合，调节心肌凋亡坏死及增殖再生。基于NSD2筛选与HuR结合且调控心室重构的circ-Cmss1（亲本基因为Cmss1），我们假设NSD2介导Cmss1启动子区H3K36me2，上调circ-Cmss1表达，诱发HuR核质易位，调控心室重构。拟在心肌肥厚模型中，以NSD2→Cmss1启动子区H3K36me2→circ-Cmss1为线索，HuR为切入点，在明确Cmss1上调circ-Cmss1基础上，利用表观遗传研究方法阐述NSD2介导H3K36me2促进Cmss1转录，调控circ-Cmss1之机制；应用RNA pull-down、RIP及FISH技术在亚细胞水平探讨circ-Cmss1-HuR相互作用，从HuR核质表达差异中探索circ-Cmss1激活HuR之机理，夯实NSD2促进circ-Cmss1诱导的HuR核质易位之效应，为实现心室重构个体化治疗不懈努力。

circRNA可与RBP结合，调节心肌凋亡坏死及增殖再生。我们以circRNA 基因芯片在心肌NSD2基因条件性敲除小鼠中筛选出差异表达显著的circCmss1，在体外实验中明确调circCmss1表达，减轻Angiotensin Ⅱ诱导的心肌肥厚后，以AAV9-shcircCmss1经尾静脉注射感染C57BL/6小鼠，发现下调circCmss1表达，减轻TAC诱导的心室重构。进一步探讨NSD2通过H3K36me2驱动Cmss1表达，上调circCmss1在心室重构中的作用。在circCmss1结合转录因子EIF4A3上调TfR1表达激活铁死亡的事件中，论述circCmss1促发心室重构的分子机制，充分阐述NSD2通过circCmss1/EIF4A3/TfR1信号促发心室重构的分子机理，有望为心室重构个体化治疗提供新靶点。