MPO, HDL Dysfunction and Cardiovascular Disease

 描述（由申请人提供）：氧化应激与动脉粥样硬化和斑块破裂有关，而动脉粥样硬化和斑块破裂是心肌梗死（MI）和猝死的主要原因。髓过氧化物酶（MPO）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定位，是氧化应激的一个良好特征来源。流行病学研究表明，在接受诊断性心导管插入术的连续受试者中，MPO水平较高的个体显示冠状动脉造影异常的可能性是最低四分位数受试者的15- 20倍。因此，MPO完全或部分缺乏的个体似乎不太可能发生CVD。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HDL。在此我们假设抑制MPO有利于HDL的质量，从而对患者发挥动脉粥样硬化保护作用。我们提出实验来确定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HDL功能的作用。我们已经使用CRISPR/Cas9技术成功地产生了MPO敲除（KO）兔。本研究将采用这些新的家兔模型。我们期望建立一个有意义的动物模型，用于MPO生物学的研究，获得新的知识，并促进基于MPO的治疗和诊断的研发。具体而言，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）使用新的兔模型确定MPO对HDL功能在动脉粥样硬化形成中的作用。有充分证据表明，小鼠不适合用于MPO生物学研究。在小鼠动脉粥样硬化组织中只能检测到微量的MPO，与人类相比相形见绌。此外，缺乏MPO的小鼠显示动脉粥样硬化增加，与在人类中观察到的相反。因此，该项目具有独特的优势，在解决这样的争论（即MPO是致动脉粥样硬化或抗动脉粥样硬化），通过使用新的MPO敲除兔模型，一个物种，一直是一个经典的模型，研究人类脂质生物学和CVD。

 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.