NOVEL MODULATORS OF ALCOHOL INDUCED METABOLIC AND LIVER INJURY

酒精引起的代谢和肝损伤的新型调节剂

• 批准号: 8203160
• 负责人: RAJ M LAKSHMAN
• 金额: $ 26.78万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8203160
• 关键词: Acetylation; Address; Affect; Alcoholic Fatty Liver; Alcohols; Attenuated; Biochemical; Books; Chemistry; Chronic; Data; Deacetylation; Down-Regulation; Enzymes; Ethanol; Experimental Models; Fatty Acids; Fatty Liver; Fatty acid glycerol esters; Genes; Gluconeogenesis; Goals; Hepatic; Histopathology; Homeostasis; Injury; Lipids; Lipoproteins; Liver; MAP Kinase Gene; MAPK14 gene; Mediating; Messenger RNA; Metabolic; Methods; Molecular Biology; Mus; Pathway interactions; Peroxisome Proliferator-Activated Receptors; Peroxisome Proliferators; Phosphorylation; Physiology; Plasma; Play; Property; Proteins; Publications; Publishing; Records; Regulator Genes; Rodent; Role; Serum; Signal Pathway; Signaling Pathway Gene; Soy Proteins; Specificity; Testing; Time; Transcription Coactivator; Up-Regulation; Western Blotting; abstracting; alcohol abuse therapy; base; clinically relevant; fatty acid oxidation; lipid biosynthesis; mouse model; novel; oxidation; oxidized lipid; prevent; problem drinker; receptor

DESCRIPTION (provided by applicant): Rationale: Chronic ethanol-induced down regulations of silence regulator gene 1 (SIRT1) and peroxisome proliferator receptor coactivator 1 alpha (PGC1alpha) and up-regulation of PGC12 affect hepatic lipid oxidation and lipogenesis leading to fatty liver and consequent injury. We show that dietary low omega3-fatty acids (omega3FA), but not high omega3FA, significantly decreased serum and liver lipids, while Soy Proteins (SP) had similar lipid lowering effects. Therefore, it is clinically relevant to prove that these two novel modulators attenuate alcohol-induced fatty liver and injury potentially by regulating these opposing PGC11 and PGC12 signaling pathway genes. Preliminary Studies: Our rationales are based on our publication records (12 Publications, 1 Review article, 1 book & 21 Abstracts in the past 5 years), and on strong preliminary data that are summarized below: Low omega3FA & SP opposed the actions of chronic alcohol by (a) Reducing serum lipids with concomitant decreased fatty liver; (b) Attenuating the up-regulation of hepatic mRNAs of PGC1beta, SREBP1c and their target lipogenic pathway genes; (c) Preventing the down-regulation of hepatic mRNAs of SIRT1 and PGC1alpha and their target fatty acid oxidation pathway genes; (d) Preventing the hepatic increase in acetyl-PGC1alpha, its inactive form; (e) Restoring impaired hepatic fatty acid oxidation and gluconeogenesis; And (f) Restoring the hepatic level of PO4AMPK that was decreased by chronic alcohol treatment. (g) By Western blots, we demonstrated concomitant changes in levels of mRNAs of PGC1alpha and PGC1beta signaling pathway genes and the corresponding enzyme proteins caused by chronic alcohol. (h) That PGC1alpha plays a critical role in alcohol- induced fatty liver was demonstrated by dramatic increase in hepatic lipid score in PGC1alpha-KO mice. (i) PGC1beta seems to play a secondary role because PGC1beta-KO mice still developed alcoholic fatty liver albeit less pronounced than in PGC1alpha-KO mice, presumably because of ethanol-mediated strong inhibition of PGC1alpha. Specific aims: Based on these rationales and preliminary findings we will address the following specific aims: Specific Aim 1. Effects of omega3FA and SP on Chronic Ethanol-induced Increases in Plasma and Hepatic Lipids and Lipoproteins, AST, ALT and Their Correlation with Liver Histopathology. Specific Aim 2. Mechanisms of Actions of omega3FA and SP on Ethanol-induced Up-regulation of Hepatic Lipid Anabolic Transcriptional Coactivators, Lipogenic Genes and de novo Lipid Synthetic Rates. Specific Aim 3. Mechanisms of Actions of omega3FA & SP on Ethanol-induced Down-regulation of Hepatic Lipid Catabolic Transcriptional Coactivators, Lipid Oxidizing Genes & Fatty Acid Oxidation Rates. Methods of Approach: PI and his team will accomplish these specific aims by using rodents as experimental models with their expertise in molecular biology, immuno- and histo-chemistry and biochemical approaches. PI will also use PGC1alpha-KO and PGC1beta-KOs mouse models to conclusively prove their specificities in the actions of ethanol, Low 3FA & SP via these signaling pathways in causing/preventing alcoholic fatty liver and injury.

描述（由申请人提供）：理由：慢性乙醇诱导沉默调节基因1 （SIRT1）和过氧化物酶体增殖体受体共激活因子1 α (pgc1α)的下调和PGC12的上调影响肝脏脂质氧化和脂肪生成，导致脂肪肝和随之而来的损伤。我们发现，饮食中低omega - 3脂肪酸（omega3FA），而不是高omega - 3fa，显著降低血清和肝脏脂质，而大豆蛋白（SP）具有类似的降脂效果。因此，证明这两种新型调节剂可能通过调节这些对立的PGC11和PGC12信号通路基因来减轻酒精诱导的脂肪肝和损伤具有临床意义。初步研究：我们的基本原理基于我们的发表记录（过去5年中12篇出版物，1篇综述文章，1本书和21篇摘要），以及强有力的初步数据，总结如下：低omega - 3fa和SP通过(a)降低血脂并伴随脂肪肝减少而反对慢性酒精的作用；(b)减弱肝脏pgc1 β、SREBP1c及其靶脂质途径基因mrna的上调；(c)防止肝脏SIRT1、pgc1 α及其靶脂肪酸氧化途径基因mrna下调；(d)防止乙酰- pgc1 α（其无活性形式）在肝脏中的增加；(e)恢复受损的肝脂肪酸氧化和糖异生；(f)恢复肝脏中因慢性酒精治疗而降低的PO4AMPK水平。(g)通过Western blots，我们发现慢性酒精引起的pgc1 α和pgc1 β信号通路基因mrna及相应酶蛋白水平的变化。(h) PGC1alpha- ko小鼠肝脂质评分显著升高，证明PGC1alpha在酒精性脂肪肝中起关键作用。(i) pgc1 - β似乎起次要作用，因为pgc1 - β - ko小鼠仍发展为酒精性脂肪肝，尽管不像pgc1 - α - ko小鼠那么明显，可能是因为乙醇介导的pgc1 - α的强烈抑制。具体目标：根据这些基本原理和初步调查结果，我们将解决以下具体目标：omega - 3fa和SP对慢性乙醇诱导的血浆和肝脏脂质、脂蛋白、AST、ALT升高的影响及其与肝脏组织病理学的相关性具体目标2。omega - 3fa和SP在乙醇诱导的肝脏脂质合成代谢转录辅激活因子、脂质生成基因和新生脂质合成率上调中的作用机制具体目标3。欧米茄3fa和SP在乙醇诱导的肝脏脂质分解代谢转录辅激活因子、脂质氧化基因和脂肪酸氧化速率下调中的作用机制方法：PI和他的团队将利用他们在分子生物学，免疫和组织化学以及生化方法方面的专业知识，以啮齿动物为实验模型来实现这些特定目标。PI还将使用pgc1 α - ko和pgc1 β - kos小鼠模型来最终证明它们在乙醇、低3FA和SP通过这些信号通路引起/预防酒精性脂肪肝和损伤中的特异性。