MPO, HDL Dysfunction and Cardiovascular Disease

 描述(申请人提供)：氧化应激与动脉粥样硬化和斑块破裂有关--心肌梗死(MI)和猝死的主要原因。氧化应激源之一是髓过氧化物酶(MPO)，这是一种血红素酶，在人类动脉粥样硬化病变中与巨噬细胞共存。流行病学研究表明，在顺序接受心导管术的受试者中，MPO水平高的个体出现冠状动脉造影异常的可能性是处于最低四分位数的受试者的15-20倍。一直以来，MPO完全或次完全缺乏的个体似乎不太可能发生心血管疾病。重要的是，MPO选择性地修饰载脂蛋白A-1(ApoA-I)，产生功能失调的高密度脂蛋白。在此，我们假设抑制MPO有利于提高高密度脂蛋白的质量，从而对患者产生动脉粥样硬化保护作用。我们建议进行实验，以确定MPO是否是减少动脉粥样硬化的有效靶点，并确定MPO在动脉粥样硬化形成中对高密度脂蛋白功能的作用。我们使用CRISPR/Cas9技术成功地培育了MPO基因敲除(KO)兔。这些新颖的兔模型将在本研究中使用。我们期望为MPO生物学的研究建立一个有意义的动物模型，获得新的知识，并促进基于MPO的治疗学和诊断学的研发。具体地说，我们将1)确定MPO是否是减少兔动脉粥样硬化的有效靶点；2)利用新的兔模型确定MPO在高密度脂蛋白功能中的作用。已经有充分的证据表明，小鼠不适合研究MPO生物学。在小鼠的动脉粥样硬化组织中只能检测到微量的MPO，与人类的组织相比相形见绌。此外，MPO缺乏的小鼠表现出动脉粥样硬化的增加，这与在人类中观察到的情况相反。因此，该项目通过使用新颖的MPO基因敲除兔模型在解决此类争论(即MPO是致动脉粥样硬化还是抗动脉粥样硬化)方面具有独特的优势，该物种一直是研究人类脂质生物学和心血管疾病的经典模型。

 DESCRIPTION (provided by applicant): Oxidative stress is implicated in atherogenesis and plaque rupture-the major cause of myocardial infarction (MI) and sudden death. One of the well-characterized sources of oxidative stress is myeloperoxidase (MPO), a heme enzyme that co-localizes with macrophages in human atherosclerotic lesions. Epidemiology studies show that individuals possessing high MPO levels among sequential subjects undergoing diagnostic cardiac catheterization were 15- to 20-fold more likely to demonstrate abnormal coronary angiograms compared with subjects in the lowest quartile. Consistently, individuals with total or subtotal MPO deficiency appear less likely to have CVD development. Importantly, MPO selectively modifies apolipoprotein A-1 (ApoA-I), generating dysfunctional HDL. Here we hypothesize that inhibiting MPO is beneficial to the quality of HDL, which consequently exert atheroprotective effects on the patients. We propose experiments to determine whether MPO is an effective target for reducing atherosclerosis, and to define the roles of MPO on HDL functionality in atherogenesis. We have successfully generated MPO knockout (KO) rabbits using the CRISPR/Cas9 technology. These novel rabbit models will be employed in the present study. We expect establishing a meaningful animal model for the study of MPO biology, gaining novel knowledge, and facilitating the R&D of MPO based therapeutics and diagnostics. Specifically, we will 1) Determine whether MPO is an effective target for reducing atherosclerosis in rabbits; 2) Define the roles of MPO on HDL functionality in atherogenesis using novel rabbit models. It is well documented that mice are not appropriate for the study of MPO biology. Only trace amount of MPO can be detected in atherosclerotic tissues in mice, dwarf to that found in human counterpart. Moreover, mice deficient of MPO showed increased atherosclerosis, opposite to what is observed in humans. This project thus has a unique advantage in resolving such debate (i.e. MPO be atherogenic or anti-atherogenic) by using the novel MPO knockout rabbit models, a species that has been a classic model to study human lipid biology and CVD.