Genetic analysis of hyperoxia-induced acute lung injury

描述(申请人提供)：急性肺损伤，包括最严重的形式--急性呼吸窘迫综合征(ARDS)，是一种毁灭性的疾病，往往是致命的，可以由许多看似无关的直接或间接肺部侮辱引起。数以百计的与疾病开始或发展有关的蛋白质已被测试，以确定它们可能的作用(S)；然而，在确定导致其发病率和死亡率的关键因素方面进展甚微。由于使用候选基因方法，死亡率在过去十年中几乎没有变化，因此替代策略对于促进我们对急性肺损伤发生和发展的病理生物学的理解是必不可少的。本研究的目的是利用急性肺损伤的小鼠模型来确定与死亡率相关的主要数量性状基因座(QTL)。为了获得这一建议的初步数据，对18个普通近交系小鼠在高氧(&gt；95%O2)中的存活时间进行了筛选，高氧是一种用于诱导急性肺损伤和ARDS的原型药物。鉴定了两种不同存活时间的小鼠模型。首先，C57BL/6J(B)小鼠是敏感的，而129X1/SVJ(S)小鼠对高氧诱导的急性肺损伤死亡的抵抗力要强得多。其次，将抗性的S品系与129P3/J(P)品系进行杂交，129P3/J(P)是129P3/J(P)品系的一个亲缘关系密切但敏感的亚系。每个小鼠模型产生的后代的初步结果表明，存在一种复杂的特征遗传模式，包括多基因和其他遗传和表观遗传因素(例如，外显性降低、双亲印记和和/或线粒体遗传)。S和P衍生组合也提示有性连锁。根据这些初步数据，我们假设高氧诱导的急性肺损伤存活率是一个数量性状，可以用近交系小鼠来模拟人类疾病进行遗传分析。对于每个小鼠模型，提出了以下三个具体目标：(1)确定总体性状遗传的可能模式(分离分析)，并估计影响反应的基因座的数量；(2)确定与高氧诱导的回交和F2小鼠急性肺损伤存活相关的遗传区域(QTL分析)；以及(3)确定与品系存活差异相关的候选和位置候选基因(微阵列分析)。通过这种结合的方法，我们希望不仅能深入了解高氧诱导的急性肺损伤的病理，而且还能了解与其他氧化剂诱导的急性肺损伤可能的相似之处。拟议的研究为一个可伸缩的问题提供了不同的视角，并可能产生进一步评估人群中潜在的疾病风险和治疗结果的遗传差异所迫切需要的宝贵信息。

DESCRIPTION (provided by applicant): Acute lung injury, including the most severe form - acute respiratory distress syndrome (ARDS), is a devastating and, too often-times, lethal condition that can result from numerous seemingly unrelated direct or indirect pulmonary insults. Hundreds of proteins associated with the initiation or progression of the disease have been tested to delineate their possible role(s); however, little progress has been made to identify the key players responsible for its morbidity and mortality. Because mortality rates have changed little over the last decade using this candidate-gene approach, alternative strategies are essential to advance our understanding of the pathobiology of acute lung injury development and progression. The goal of this research is to use mouse models of acute lung injury to identify the major quantitative trait loci (QTLs) linked to mortality. To gain preliminary data for this proposal 18 common inbred mouse strains were screened for survival time in hyperoxia (>95% O2), a prototypic agent used to induce acute lung injury and ARDS. Two mouse models of differential survival time were identified. First, C57BL/6J (B) mice are sensitive, whereas 129X1/SvJ (S) mice are much more resistant to hyperoxia-induced acute lung injury mortality. Second, the resistant S strain was combined with 129P3/J (P), a closely related, but sensitive sub strain of the 129 line. Initial results with offspring generated for each mouse model suggested a complex mode of trait inheritance, including multiple genes and other genetic and epigenetic factor(s) (e.g., decreased penetrance, parental imprinting, and and/ or mitochondrial inheritance). S and P-derived crosses also suggested sex linkage. From these preliminary data, we hypothesize that hyperoxia-induced acute lung injury survival is a quantitative trait that is amenable to genetic analysis using inbred strains of mice to model the human disease. For each mouse model, the following three specific aims are proposed: (1) determine the likely mode of overall trait inheritance (segregation analysis) and estimate the number of loci contributing to the response; (2) identify genetic regions linked to hyperoxia-induced acute lung injury survival in backcross and F2 mice (QTL analysis) generated from strains of each model; and (3) identify candidate and positional candidate genes associated with the strain survival differences (microarray analysis). With this combined approach, we expect to gain insight into not only the pathology of hyperoxia-induced acute lung injury, but also the possible similarities to other oxidant-induced acute lung injuries. The proposed studies offer a different perspective to a retractable problem and could yield valuable information urgently needed to further assess genetic differences underlying disease risks and therapeutic outcomes in the population.