Dyslipidemia, Lipoic Acid and Diabetic Vascular Complications in Humanized

人源化血脂异常、硫辛酸和糖尿病血管并发症

• 批准号: 7148777
• 负责人: NOBUYO MAEDA
• 金额: $ 36.18万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-04 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7148777
• 关键词: antioxidants; apolipoprotein E; atherosclerosis; blood lipoprotein metabolism; cardiovascular disorder risk; cooperative study; diabetes mellitus genetics; diabetic angiopathy; disease /disorder model; fatty acid synthase; gene expression; genetic manipulation; genetic polymorphism; genetic regulation; genetic susceptibility; high density lipoproteins; human genetic material tag; hyperlipidemia; laboratory mouse; low density lipoprotein; low density lipoprotein receptor; medical complication; model design /development; oxidative stress; pathologic process; protein isoforms; short chain fatty acid; species difference

DESCRIPTION (provided by applicant): While diabetes mellitus can lead to serious damage to many organs, cardiovascular diseases are the major cause of death and morbidity in diabetic patients. Overall, patients with diabetes have a three to five fold increased risk of coronary artery diseases compared to non-diabetics. Our goal is to use mouse genetics for identifying genetic risk factors for the vascular complications of diabetes and for unraveling underlying mechanisms. Although a significant increase in atherosclerosis by diabetes has been demonstrated in atherogenic mouse models, none of these mouse models faithfully replicates the types of dyslipidemia associated with diabetes in humans. We postulate that this failure is due to differences in the relative levels of plasma low density lipoprotein (LDL) and plasma high density lipoprotein (HDL) that are controlled by genetic differences between the two species and genetic polymorphisms in humans. Thus our first hypothesis is that humanizing genes that are involved in lipoprotein metabolism in mice so that they develop a more human-like diabetic dyslipidemia will cause them to replicate better the cardiovascular problems of human diabetic patients. We will test this hypothesis in Specific Aim 1 by inducing diabetes in mice with humanized apoE of the three isoforms (E2, E3, and E4) and humanized LDL receptor (LDLR), with or without overexpression of human apoB. We predict that this will lead to diabetic dyslipidemia and accelerated atherosclerosis in an apoE isoform dependent manner. Our second hypothesis is that since diabetes is generally acknowledged to induce oxidative stress, genetically determined differences in the levels of endogenous anti-oxidants affect the development of cardiovascular complications,. To test this hypothesis, we propose in Specific Aim 2 to develop a new mouse model with a genetically controlled reduction in the production of the endogenous antioxidant lipoic acid (LA). We will modify the LA synthase (Lias) gene in such a way that the stability of Lias mRNA will be drastically reduced in a tissue specific fashion. Our hypothesis predicts that reduced production of LA will increase the oxidative stress already present in diabetic mice and enhance their development of vascular complications. In Specific Aim 3, we propose to combine human-like diabetic dyslipidemia with genetically reduced antioxidant capacity due to LA deficiency to test our overall thesis that interactions between genetic polymorphic differences affecting lipid profiles and genetic differences affecting endogenous antioxidant levels determine the degree to which diabetes enhances cardiovascular disease.

描述（由申请人提供）： 虽然糖尿病可导致许多器官的严重损害，但心血管疾病是糖尿病患者死亡和发病的主要原因。总的来说，糖尿病患者患冠状动脉疾病的风险比非糖尿病患者高出三到五倍。我们的目标是利用小鼠遗传学来确定糖尿病血管并发症的遗传风险因素，并揭示潜在的机制。虽然在致动脉粥样硬化小鼠模型中已经证明糖尿病导致的动脉粥样硬化显著增加，但是这些小鼠模型都没有忠实地复制与人类糖尿病相关的血脂异常类型。我们推测，这种失败是由于血浆低密度脂蛋白（LDL）和血浆高密度脂蛋白（HDL）的相对水平的差异，这是由两个物种之间的遗传差异和人类的遗传多态性控制。因此，我们的第一个假设是，人源化参与小鼠脂蛋白代谢的基因，使它们发展出更像人类的糖尿病血脂异常，将使它们更好地复制人类糖尿病患者的心血管问题。我们将在特异性目的1中通过用三种亚型（E2、E3和E4）的人源化apoE和人源化LDL受体（LDLR）诱导小鼠糖尿病，伴或不伴人apoB过表达来检验这一假设。我们预测，这将导致糖尿病血脂异常和加速动脉粥样硬化的apoE亚型依赖的方式。我们的第二个假设是，由于糖尿病通常被认为会诱导氧化应激，内源性抗氧化剂水平的遗传决定差异会影响心血管并发症的发展。为了验证这一假设，我们在特定目标2中提出开发一种新的小鼠模型，该模型具有内源性抗氧化剂硫辛酸（LA）产生的遗传控制减少。我们将修改LA合酶（Lias）基因，以这样的方式，Lias mRNA的稳定性将大大降低在组织特异性的方式。我们的假设预测，减少生产的LA将增加氧化应激已经存在于糖尿病小鼠，并提高他们的血管并发症的发展。在具体目标3中，我们建议将联合收割机类人糖尿病血脂异常与由于LA缺乏导致的遗传性抗氧化能力降低相结合，以检验我们的总体论点，即影响脂质谱的遗传多态性差异与影响内源性抗氧化水平的遗传差异之间的相互作用决定了糖尿病增强心血管疾病的程度。