MOLECULAR BASIS OF OXIDATIVE MODIFICATION OF LDL

大量证据表明，氧化性物质的过度积累- 动脉巨噬细胞修饰的低密度脂蛋白 WALL参与了动脉粥样硬化性斑块的发病机制。 低密度脂蛋白的氧化修饰涉及其衍生化 通过脂质过氧化的分解产物组成载脂蛋白B， 很大程度上是由反式-4-羟基-2-壬烯醛(HNE)引起的。的许多属性 氧化低密度脂蛋白，如脂褐素样荧光的发展和 聚集的趋势，可以通过直接处理低密度脂蛋白来复制 和海妮在一起。HNE-蛋白质加合的化学非常复杂，是 异质性，部分服从可逆平衡，并与 与时间依赖和自氧化依赖的加合物“老化”和 分子间交联势。我们的总体工作假设是 可以确定HNE加合物结构中的这种进化 通过表位表达的变化和部分通过 用组特异性试剂和氚HNE进行生物化学研究 探测器。被巨噬细胞内化的氧化低密度脂蛋白似乎 在HNE加合物结构上经历类似的变化，就像OX-LDL存在于 人类动脉粥样硬化病变的细胞外间隙。 建议的工作，反映了汇集的多学科专业知识 在邻近研究机构的三名高级调查人员中， 涉及模型中HNE内收化学的详细表征 仿生学研究，随后是抗体的开发 识别个别类型的HNE-低密度脂蛋白修饰。这些抗体 然后将用于免疫化学检测特定的HNE加合物 低密度脂蛋白。和氧化低密度脂蛋白在体外，对氧化低密度脂蛋白已内化在 培养的巨噬细胞，以及在手术中获得的动脉粥样硬化病变中。 HNE-低密度脂蛋白加合物出现的时空模式将被关联 低密度脂蛋白修饰的功能后果是蓄积 巨噬细胞通过特异性受体摄取和易感性 溶酶体在其中降解。(一)明确的主要特点 加合物结构的测定和(Ii)抗体的特异性 被视为澄清哪些修改的关键要求 在氧化低密度脂蛋白中的出现与动脉粥样硬化的特性最相关，并且 它们是HNE所特有的。

Substantial evidence suggests that the over-accumulation of oxidatively- modified low density lipoprotein (ox-LDL) by macrophages in the arterial wall contributes to the pathogenesis of atherosclerotic.plaques. Oxidative modification of LDL involves the derivatization of its constituent apolipoprotein B by breakdown products of lipid peroxidation, to a large degree by trans-4-hydroxy-2-nonenal (HNE). Many properties of ox-LDL, such as development of lipofuscin-like fluorescence and the tendency toward aggregation, can be reproduced by direct treatment of LDL with HNE. The chemistry of HNE-protein adduction is highly complex, being heterogeneous, in part subject to reversible equilibria, and associated with time-dependent and autoxidation-dependent adduct "aging" and intermolecular crosslinking potential. Our overall working hypothesis is that such evolution in HNE adduct structure can be identified immunochemically by changes in epitope expression and, in part, through biochemical studies using group-specific reagents and tritiated HNE probes. Ox-LDL which has been internalized by macrophages appears to undergo a similar shift in HNE adduct structure, as does ox-LDL present in the extracellular space of human atherosclerotic lesions. The work proposed, which reflects the pooled multi-disciplinary expertise of three senior investigators at neighboring research institutions, involves a detailed characterization of HNE adduction chemistry in model physiomimetic studies, followed by the development of antibodies which recognize individual types of HNE-LDL modifications. These antibodies will then be used for immunochemical detection of specific HNE adducts on HNE-LDL. arid ox-LDL in vitro, on ox-LDL which has been internalized in cultured macrophages, and in atherosclerotic lesions obtained at surgery. The spatiotemporal pattern of HNE-LDL adduct appearance will be correlated with functional consequences of LDL modification in terms of accumulation in macrophages via specific receptor uptake and susceptibility to lysosomal degradation therein. The key features of (i) unambiguous determination of adduct structure and (ii) antibody specificity, are viewed as crucial requirements for clarifying which modifications occurring in ox-LDL are most associated with atherogenic properties, and which are specific to HNE.