Genetic analysis of neointimal hyperplasia

描述（由申请人提供）：再狭窄仍然是限制血管成形术和/或支架置入术成功的最重要的临床挑战。内膜增生是支架内再狭窄的主要原因。本研究的目的是利用损伤诱导的新生内膜增生小鼠品系之间的差异来确定导致血管成形术/支架后再狭窄的遗传因素。在载脂蛋白e缺乏（apoE-/-）的背景下，近交系小鼠C57BL/6J （B6）和C3H/HeJ （C3H）在损伤性内膜增生方面存在显著差异。B6。apoE-/-小鼠易发生新生内膜增生，而CSH。apoE-/-小鼠完全抵抗病变的形成，尽管这两种菌株在饮食中具有相似的高脂血症。F1杂交种在表型上处于中间位置，表明小鼠的表型存在共显性控制。动脉损伤后立即在血管损伤部位沉积一层血小板。随后，白细胞聚集和浸润发生。募集的巨噬细胞和淋巴细胞以及受损的内皮细胞和血管平滑肌细胞（SMC）释放细胞因子、生长因子和基质金属蛋白酶（MMP），刺激内侧壁的SMC增殖并迁移到受损的内膜。我们推测，影响细胞因子和生长因子诱导或调节血管平滑肌细胞增殖的遗传因素导致了两种菌株新内膜增生的差异。为了验证这个假设，B6。apoE-/-小鼠将与CSH配对。apoE-/-小鼠产生F1小鼠，这些小鼠随后将交叉产生F2小鼠。雄性F2小鼠，以及雄性F1和两个亲本品系，将遭受左侧颈总动脉内皮剥落。新内膜增厚将在光镜下定量。将采集血液以评估空腹脂质和炎症标志物水平。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。在基因组筛选检测到与新内膜病变相关的染色体区域后，我们将输入额外的紧密间隔多态性标记以缩小区域。通过基因菌株的构建和分析，将剖析1 - 2个主要的内膜增生qtl。

DESCRIPTION (provided by applicant): Restenosis remains the most significant clinical challenge limiting the success of angioplasty and/or stenting. Neointimal hyperplasia is the primary reason for in-stent restenosis. The objective of this proposal is to use variations among mouse strains in injury-induced neointimal hyperplasia to identify genetic factors that contribute to the development of post-angioplasty/stent restenosis. On the apolipoprotein E-deficient (apoE-/-) background, inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) differ markedly in injury-induced neointimal hyperplasia. B6.apoE-/- mice readily develop neointimal hyperplasia whereas CSH.apoE-/- mice are totally resistant to lesion formation despite the fact that the two strains have comparable hyperlipidemia on a chow diet. The F1 hybrids are intermediate in the phenotype, indicating a codominant control of the phenotype in the mice. Immediately following arterial injury is deposition of a layer of platelets at sites of vascular injury. Subsequently, leukocyte recruitment and infiltration occur. Recruited macrophages and lymphocytes and damaged endothelial cells and vascular smooth muscle cells (SMC) release cytokines, growth factors, and matrix metalloproteinases (MMP) that stimulate SMC in the medial wall to proliferate and migrate into the damaged intima. We hypothesize that genetic factors that influence the induction of cytokines and growth factors or that modulate the proliferation of vascular smooth muscle cells contribute to the variation in neointimal hyperplasia of the two strains. To test this hypothesis, B6.apoE-/- mice will be mated with CSH.apoE-/- mice to generate F1 mice, which will be subsequently intercrossed to generate a cohort of F2 mice. The male F2 mice, together with male F1 and two parental strains, will be subject to endothelial denudation of the left common carotid artery. Neointimal thickening will be quantitated by light microscopy. Blood will be collected for assessment of fasting lipid and inflammatory marker levels. Genome-wide scans will be performed using microsatellite markers to define the genetic loci that are linked to differences in the phenotypes between B6 and C3H strains. After the genome screen has detected chromosomal regions that show linkage with neointimal lesions, we will type additional closely spaced polymorphic markers to narrow the regions. One to two major QTLs for neointimal hyperplasia will be dissected through construction and analysis of congenic strains.