Genetic analysis of neointimal hyperplasia

描述（由申请人提供）：呼吸困难仍然是限制血管成形术和/或支架植入术成功的最重要临床挑战。新生内膜增生是支架内再狭窄的主要原因。该提案的目的是利用损伤诱导的新生内膜增生中小鼠品系之间的差异来识别导致血管成形术/支架后再狭窄发展的遗传因素。在载脂蛋白E缺陷（apoE-/-）的背景下，近交系小鼠品系C57 BL/6 J（B6）和C3 H/HeJ（C3 H）在损伤诱导的新生内膜增生方面明显不同。B6.apoE-/-小鼠容易发生新生内膜增生，而CSH.apoE-/-小鼠完全抵抗损伤形成，尽管事实上这两种品系在食物饮食中具有相当的高脂血症。F1代杂种在表型上是中间型，表明小鼠表型的共显性控制。动脉损伤后，血管损伤部位立即沉积一层血小板。随后，发生白细胞募集和浸润。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），刺激中膜壁中的SMC增殖并迁移到受损内膜中。我们推测，影响细胞因子和生长因子的诱导或调节血管平滑肌细胞增殖的遗传因素有助于两种菌株的新生内膜增生的变化。为了检验这一假设，将B6.apoE-/-小鼠与CSH.apoE-/-小鼠交配以产生F1小鼠，随后将其交叉以产生F2小鼠队列。雄性F2小鼠以及雄性F1和两个亲本品系将经受左颈总动脉的内皮剥脱。新生内膜增厚将通过光学显微镜进行定量。将采集血液用于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C3 H菌株之间表型差异相关的遗传基因座。在基因组筛查检测到与新生内膜病变相关的染色体区域后，我们将对其他间隔紧密的多态性标记进行分型，以缩小区域范围。将通过构建和分析同源菌株来剖析新生内膜增生的一至两个主要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.