QTL analysis of carotid atherosclerosis

描述（由申请人提供）：中风是美国第三大死亡原因和致残原因，很大一部分缺血性中风是由颈动脉粥样硬化引起的，颈动脉粥样硬化导致血管狭窄，阻断流向大脑的血液。本研究的目的是利用新型载脂蛋白e缺陷（apoE-/-）小鼠模型，确定促进颈动脉粥样硬化发展的遗传因素。具有C57BL/6 （B6）遗传背景的ApoE-/-小鼠在人类颈动脉中出现了所有阶段的动脉粥样硬化病变。我们最近的研究表明，通过与C3H/HeJ （C3H）小鼠杂交，病变可以显着减少，证明了小鼠疾病过程的遗传控制。在体外实验中，C3H小鼠内皮细胞对氧化LDL的反应不如B6内皮细胞。我们假设影响氧化LDL反应的基因改变有助于C3H小鼠对颈动脉粥样硬化的抵抗。为了验证这个假设，B6。apoE-/-小鼠将与C3H杂交。apoE-/-小鼠产生F1小鼠，随后交叉产生F2小鼠。从6周龄开始，F2小鼠与F1及两亲本品系一起饲喂西餐12周。通过光学显微镜测量颈动脉粥样硬化病变。采集血液检测空腹血脂和炎症指标。将使用微卫星标记进行全基因组扫描，以确定与B6和C3H菌株之间表型差异相关的遗传位点。将进行标记和表型的统计关联，以确定潜在性状的位点。在基因组筛选检测到与动脉粥样硬化病变相关的染色体区域后，我们将键入其他紧密间隔的多态性标记。通过基因菌株的构建，将分离出一到两个与动脉粥样硬化病变相关的主要qtl。

DESCRIPTION (provided by applicant): Stroke is the third leading cause of mortality and the leading cause of disability in the United States, and a significant fraction of ischemic strokes are caused by carotid atherosclerosis, which results in stenosis of the vessels and blocks the blood flow to the brain. The goal of this proposal is to identify genetic factors that contribute to the development of carotid atherosclerosis, using the novel apolipoprotein E-deficient (apoE-/-) mouse model. ApoE-/- mice on the C57BL/6 (B6) genetic background develop all phases of atherosclerotic lesions seen in humans in carotid arteries. Our recent studies show that the lesions can be dramatically diminished by outcross with C3H/HeJ (C3H) mice, demonstrating the genetic control of the disease process in the mice. In vitro, endothelial cells of C3H mice are not as responsive to oxidized LDL as B6 endothelial cells. We hypothesize that a genetic alteration that influences the response to oxidized LDL contributes to the resistance of C3H mice to carotid atherosclerosis. To test this hypothesis, B6.apoE-/- mice will be crossed with C3H.apoE-/- mice to generate F1 mice, which will be subsequently intercrossed to generate F2 mice. Starting at 6 weeks of age, the F2 mice, together with the F1 and the two parental strains, will be fed a Western diet for 12 weeks. Atherosclerotic lesions in carotid arteries will be measured by light microscopy. Blood will be collected for fasting lipid profiles and inflammatory markers. Genome wide scan will be performed using microsatellite markers to define the genetic loci that are linked to differences in phenotypes between B6 and C3H strains. Statistical associations of the markers and the phenotypes will be performed to identify loci underlying the traits. After the genome screen has detected chromosomal regions that show linkage with atherosclerotic lesions, we will type additional closely spaced polymorphic markers. One to two major QTLs for atherosclerotic lesions will be dissected through construction of congenic strains.