Light & Heavy Alcohol, Paraoxonase & Oxidized LDL Status

描述（由申请人提供）：LDL被氧化为氧化LDL (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hdl结合的多态酶，可降低OxLDL水平，从而预防CAD。PI假设，少量饮酒（13-40 g/天）可增加血清PON水平，从而通过阻止或破坏OxLDL的形成而降低其水平，从而具有心脏保护作用，而大量饮酒（80 g/天）则具有相反的效果。PI有以下新数据来支持他的假设：与不饮酒者相比，轻度饮酒者的Sewn PON活性增加了3.95倍（p< 0.01），而重度饮酒者的Sewn PON活性下降了45% （p<0.001）。2. HDL- pon抑制LDL氧化，这是由HDL事先与抗pop4或EDTA孵育所阻止的。3. HDL-PON也破坏OxLDL并抑制巨噬细胞对OxLDL的摄取。4. 与对照组相比，轻度酒精喂养的大鼠肝脏PON mRNA相对于GAPDH mRNA增加了59% (p < 0.001)，重度酒精喂养的大鼠减少了51% （p < 0.001）。因此，PI建议描述酒精对PON和OxLDL状态产生截然相反的作用。人类研究：PI将由合格的心脏病专家在4周和8周戒酒前后检测无肝病的轻度、重度和非饮酒者的血清PON活性和蛋白质，并与血浆氧化LDI状态和CAD发病率相关。PI将测试每个研究组的血清样本(i)抑制LDL氧化（ii）破坏OxLDL和（iii）阻止巨噬细胞摄取OxLDL的能力。PI还将对研究组的PON基因进行基因型分析，以确定它们对轻度和重度饮酒的易感性。最后，PI将测试轻度或重度饮酒是否上调或下调PON3等位酶。大鼠研究：由于PON仅在肝脏中表达（PON3除外），酒精对POT的分子调控只能在明确条件下的动物系统（如大鼠）中进行研究，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稳定性试验确定乙醇是否在转录或转录后水平调节PCI mRNA。这些研究可能会在临床和分子水平上为我们对饮酒的心脏保护作用和大量饮酒的动脉粥样硬化作用的理解带来新的见解。

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.