VPO1/HOCl通路介导的氧化应激在高脂血症内皮祖细胞衰老中的作用及机制研究

The senescence of EPC in patients with hyperlipidemia is accelerated. But the underlying mechanisms are not fully understood. Our previous work has firstly demonstrated that VPO1/HOCl pathway -mediated oxidative stress is closely related to the development of multiple cardiovascular pathological phenomena. It is first time for this project to explore the role of VPO1/HOCl pathway-mediated oxidative stress in EPC senescence in patients with hyperlipidemia and the underlying mechanisms. First, clinical study will be carried out. The measurements, such as EPC senescent ratio in peripheral blood, HOCl level, VPO1 expression and β-catenin pathway, et al. well be finished and the correlation between EPC senescence and the expression of VPO1 or the activation of β-catenin pathway will be evaluated. Then, animal models of hyperlipidemia will be established. Through combining the strategies of drug interference, the role of VPO1/HOCl pathway-mediated oxidative stress in promotion of EPC senescence and the involvement of β-catenin pathway will be preliminary confirmed. Finally, a model of ox-LDL or HOCl-induced EPC senescence will be established. Through combining the strategies of RNA interference and gene over-expression, the role of VPO1/HOCl pathway in promotion of EPC senescence and the underlying mechanisms will be elucidated. The aims of this project are to provide theoretic foundation and new idea for seeking novel drug targets against EPC senescence.

高脂血症患者EPC衰老加速，但机制尚未完全阐明。我们前期工作首次发现VPO1/HOCl通路介导的氧化应激与多种心血管病理现象的发生密切相关。本项目率先探讨VPO1/HOCl通路介导的氧化应激在高脂血症EPC衰老中的作用及机制。首先，从临床研究入手，通过检测EPC衰老率、HOCl水平、VPO1表达及β-catenin信号途径等相关指标，初步评估高脂血症患者外周血EPC衰老加速与VPO1表达上调及β-catenin信号途径激活的正向关系；然后，利用高脂血症动物模型，结合药物干预，初步确定VPO1/HOCl通路介导的氧化应激促EPC衰老作用以及与β-catenin信号途径的关系；最后，建立ox-LDL或HOCl诱导的EPC细胞衰老模型，结合基因沉默、基因超表达等技术阐明VPO1/HOCl通路促EPC衰老的作用及机制。本项目将有助于阐明EPC 衰老机制，为开发保护血管内皮新药提供新思路。

高脂血症患者EC/EPC衰老加速，但机制尚未完全阐明。我们前期工作首次发现VPO1/HOCl通路介导的氧化应激与多种心血管病理现象的发生密切相关。本项探讨了VPO1/HOCl通路介导的氧化应激在高脂血症EC/EPC衰老中的作用及机制。本项目的主要发现包括：高脂血症大鼠及高脂血症患者外周血内皮祖细胞衰老率明显增加，VPO1、β-catenin和p-53蛋白表达水平上调；ox-LDL诱导的内皮祖细胞衰老组，VPO1上游途径分子Nox2，Nox4的蛋白表达均增高，VPO1的底物H2O2水平显著升高；VPO1上游途径分子Nox2，Nox4同样加速高脂血症内皮祖细胞的衰老，而nmMLC20磷酸化可抑制Nox2，和Nox4表达，延缓内皮祖细胞衰老；高脂血症大鼠血管内皮细胞VPO1同工酶MPO表达显著上调，伴随内皮细胞衰老明显加速，血管内皮依赖舒张功能显著降低；VPO1/HOCl通路还可促进高脂血症内皮细胞程序性坏死，而阿托伐他汀可通过抑制VPO1/HOCl通路延缓高脂血症诱导的内皮细胞衰老。这些结果表明VPO1/HOCl通路在促进高脂血症血管内皮衰老和死亡中发挥重要作用，其机制可能涉及β-catenin/p53途径。本项目为阐明高脂血症血管内皮损伤的机制提供新的实验依据，也为寻找血管内皮保护药物提供新的药物干预靶点和新思路。