KLF5苏素化在血管平滑肌细胞表型转化中的作用

In this study, we used human normal or vascular hyperplasia tissues, differentiation or dedifferentiation human aortic smooth muscle cells as target, to investigate the role of KLF5 SUMOylation and mechanism of KLF5 actions in regulating VSMC specific genes expression as well as histone acetylation using MiRNA arrays, ChIP sequencing, RNA interference, KLF5 modification sites mutation, Oligo pull down, EMSA and reporter gene assay, etc. The aim is to explore the relationship between KLF5 SUMOylation and acetylation/deacetylation, methylation/ demethylation of histone H3 and H4, identify the model and mechanism of MiRNA regulated the KLF5 SUMOylation and VSMC remodeling. These researches will further find out the molecular mechanism manipulating the VSMC phenotype from the epigenetic aspect and provide a new therapeutic basis and target of vascular remodeling diseases.

本项目以人正常血管、内膜增生的肾血管组织和分化型、去分化型主动脉平滑肌细胞(HASMC)为研究对象，应用MiRNA芯片、ChIP sequencing, RNA干扰、KLF5修饰位点突变、Oligo pull down、EMSA和报告基因分析等技术研究研究KLF5苏素化调节VSMC特异基因表达的分子机制，探明KLF5苏素化修饰与组蛋白乙酰化/去乙酰化以及甲基化/去甲基化等表观遗传学变化的关系，明确MiRNA调节KLF5苏素化及VSMC表型重塑的组合作用模式，从表观遗传学角度探讨VSMC表型转化的分子机制，为防治血管重塑性疾病提供新的治疗依据和药物靶点。

本项目主要研究KLF5苏素化调节VSMC特异基因表达的分子机制，探明KLF5苏素化修饰与组蛋白乙酰化/去乙酰化以及甲基化/去甲基化等表观遗传学变化的关系，明确miR-29a,miR-155调节KLF5苏素化及VSMC表型重塑的组合作用模式，从表观遗传学角度探讨VSMC表型转化的分子机制，为防治血管重塑性疾病提供新的治疗依据和药物靶点。研究发现(1) miR-200c-苏素化KLF4反馈环路是调控VSMC表型转化和增殖的重要开关。（2）苏素化KLF4通过逆转PDGF-BB诱导的p21表达调控平滑肌细胞增殖。（3）发现KLF5, MiR-29a 以及Fbw7/CDC4共同调控动脉粥样硬化的进程，其机制与KLF5的泛素化相关。（4）平滑肌源性KLF5通过诱导miR-155表达和分泌调控内皮细胞的屏障功能参与动脉粥样硬化的进程。（5）KLF4的磷酸化修饰通过调控内皮紧密连接蛋白的表达参与内皮细胞的拍屏障功能调控。（6）缺氧改变KLF4和KLF5的苏素化状态调控内皮功能。