circ-Sirt6与Ets-1互作参与血管平滑肌细胞炎症表型转化的机制研究

The Inflammatory phenotypic switching of vascular smooth muscle cells(VSMCs) leads to vascular remodelling and cardiovascular disease.circRNA is a special class of endogenous lncRNAs,it can form protein-RNA complex to regulate downstream signaling pathways.We found that the SIRT6 host gene can produce circ-Sirt6. We validated that the expression of circ-Sirt6 was decreased in rat carotid artery tissue and TNF-α-treated VSMCs. Rip assay and RNA pull-down assay showed that the circ-Sirt6 and Ets-1 bind to each other.Therefore, we guess that circ-Sirt6 interact with Ets-1 to inhibit inflammatory phenotypic transformation of VSMCs. This study intends to use molecular biology technologies to reveal the key of circ-Sirt6 anti-inflammatory and clarify how circ-Sirt6 mediates nuclear translocation and deacetylation modification of Ets-1 in the inflammatory phenotypic transformation of VSMCs.In summary,our study will demonstrate that circ-Sirt6 inhibit the inflammatory phenotype of VSMCs, and provide novel molecular insight into the mechanisms of circRNAs in VSMC homeostasis and new therapeutic strategies for vascular diseases.

血管平滑肌细胞（VSMCs）的炎症表型转化是诸多心血管疾病的病理生理基础。circRNAs对血管炎症的作用及调控机制尚不清楚。预实验显示，SIRT6基因编码的circ-Sirt6在损伤后大鼠颈动脉组织中表达显著减少。对VSMCs敲低circ-Sirt6，炎症标志分子表达上调。进一步研究发现circ-Sirt6定位于VSMCs胞浆和胞核，与炎症相关转录因子Ets-1相互作用。据此进行科学假设：circ-Sirt6与Ets-1互作抑制VSMCs炎症表型转化。本课题拟通过对体外细胞和临床标本进行检测、动物实验进一步验证，揭示circ-Sirt6与血管炎症发生发展的关系；采用RIP等技术从分子水平揭示circ-Sirt6抑炎关键节点，阐明不同亚细胞定位的circ-Sirt6介导Ets-1核转位、去乙酰化修饰在VSMCs炎症表型转化中的作用。为系统阐明血管炎症调控机制、临床药物研发奠定理论基础。

本研究通过使用大鼠颈动脉球囊损伤动物模型和PDGF-BB诱导的血管平滑肌细胞增殖模型，试图从体内外证实circ-sirt6在VSMC增殖和血管损伤后内膜增生进程中的作用，并探讨其作用机制，以期为揭示血管重构相关心血管疾病的发生机制提供研究证据。. 我们发现，过表达circ-sirt6可抑制细胞增殖、迁移，促进VSMC收缩型标志物calponin等表达。机制研究显示，circ-Sirt6作为桥联分子，促进NEDD4和Grb10结合进而诱导表皮生长因子受体EGFR泛素化降解，EGFR表达下调，血管平滑肌细胞增殖受抑制。circ-sirt6-Grb10-NEDD4-EGFR轴可能是抑制VSMC增殖和血管内膜增生的新机制。.