Light & Heavy Alcohol, Paraoxonase & Oxidized LDL Status

描述(申请人提供)：低密度脂蛋白被氧化为氧化型低密度脂蛋白(OxLDL)，被巨噬细胞迅速摄取，导致冠状动脉疾病(CAD)。对氧磷酶(PON)是一种高密度脂蛋白结合的多态酶，可降低OxLDL水平，从而预防冠心病。PI假设，少量饮酒(13-40克/天)会增加血清PON水平，从而通过阻止其形成或破坏它来降低OxLDL，从而具有心脏保护作用，而大量饮酒(&gt；80克/天)则具有相反的效果。PI有以下新数据支持他的假设：1.与非饮酒者相比，少量饮酒者的SEWN PON活性增加3.95倍(P&lt；0.001)，而重度饮酒者的SEWN PON活性降低45%(P&lt；0.01)。2.高密度脂蛋白-PON可抑制低密度脂蛋白氧化，这一作用可通过预先将高密度脂蛋白与抗POP4抗体或EDTA孵育而阻止。3.高密度脂蛋白-PON还可破坏OxLDL，抑制巨噬细胞摄取OxLDL。4.与对照组相比，轻度酒精喂养的大鼠肝脏PON基因相对GAPDHmRNA的表达增加了59%(p&lt；0.001)，而重度酒精喂养的大鼠肝脏PON基因的相对含量降低了51%(p&lt；0.001)。因此，PI建议描述酒精对PON和OxLDL状态造成截然相反的影响的作用。人体研究：PI将测定无肝病的轻度、重度和非饮酒者在戒酒前和戒酒4-8周前后的血清PON活性和蛋白，并与合格心脏病专家的血浆氧化型LDI状态和冠心病发病率相关。PI将测试来自每个研究小组的血清样本的能力：(1)抑制低密度脂蛋白氧化；(2)破坏氧化低密度脂蛋白；(3)防止巨噬细胞摄取氧化低密度脂蛋白。PI还将对研究组中的PON基因进行基因分型，以关联他们对轻度和重度饮酒的易感性。最后，PI将测试少量或大量饮酒是否上调或下调PON3等位酶。在大鼠中的研究：由于PON只在肝脏表达(PON3除外)，酒精对PON的分子调控只能在像大鼠这样的动物系统中在明确的条件下进行研究，PI将分别通过Western Blot和Northern Blot分析确定乙醇剂量和暴露时间对肝脏PON浓度及其mRNA水平的影响。然后，PI将通过核运行和mRNA稳定性分析来确定乙醇是在转录水平还是在转录后水平调节PCImRNA。这些研究可能会在临床和分子水平上引导我们对UGH饮酒的心脏保护作用和大量饮酒的动脉粥样硬化前病变的理解的新见解。

DESCRIPTION (provided by applicant): LDL is oxidized to oxidized LDL (OxLDL) that is rapidly taken up by macrophages leading to coronary artery disease (CAD). Paraoxonase (PON), a HDL-bound polymorphic enzyme, lowers OxLDL level and thus prevents CAD. The PI hypothesizes that light drinking (13-40 g/day) increases serum PON level and thereby lowers OxLDL by preventing its formation or by destroying it and thus has a cardioprotective effect, whereas heavy drinking (>80 g/day) has the opposite effects. The PI has the following new data to support his hypothesis: 1. Sewn PON activity is increased 3.95-fold (p<0.0O1) in light drinkers, but decreased by 45 percent (p<0.001) in heavy drinkers compared to nondrinkers. 2. HDL-PON inhibited LDL oxidation that is prevented by prior incubation of HDL with either anti-POP4 or EDTA. 3. HDL-PON also destroyed OxLDL and inhibited OxLDL uptake by macrophages. 4. Hepatic PON mRNA relative to GAPDH mRNA is increased by 59 percent (p < 0.001) in light alcohol-fed and decreased by 51 percent (p < 0.001) in heavy alcohol-fed rats compared to controls. Therefore, the PI proposes to delineate the action of alcohol in causing diametrically opposite effects on PON and OxLDL status. Studies in humans: The PI will determine serum PON activity and protein in light, heavy and non-drinker without liver disease before and after 4- & 8-week abstinence and correlate with plasma oxidized LDI status and incidence of CAD by qualified cardiologists. The PI will test serum samples from each study group for their ability to (i) inhibit LDL oxidation (ii) destroy OxLDL and (iii) prevent OxLDL uptake by macrophages. The PI will also genotype PON genes in the study groups to correlate their susceptibility to light and heavy alcohol drinking. Finally, the PI will test whether light or heavy drinking up-regulated or down-regulates PON3 allozyme. Studies in rats: Since PON is expressed only in the liver (except PON3), molecular regulation of POT by alcohol can only be studied in an animal system like rat under well-defined conditions, the PI will determine the effects of ethanol dosage and duration of exposure on hepatic PON concentration and its mRNA level b Western Blot and Northern Blot analyses, respectively. The PI will then determine whether ethanol regulates PCI mRNA at transcriptional or post-transcriptional level by Nuclear-run-on and mRNA stability assays. These investigations are likely to lead to new insights in our understanding of the cardioprotective effects of Ugh drinking and proatherogenic effects of heavy drinking both at clinical and at molecular levels.