Mapping Murine Regeneation Genes

描述（由申请人提供）：伤口和组织损伤是常见的医疗问题，通常会导致过度瘢痕形成，随后丧失器官功能，而无需正常组织替代。了解控制无瘢痕再生愈合的分子可以提供一种调节愈合和减轻这些对公共健康的重大威胁的方法。我们以前已经证明，成年MRL小鼠显示出独特的无瘢痕和再生型愈合。在这些小鼠中，贯穿耳孔的伤口完全闭合，而其他小鼠的伤口则留下疤痕。MRL小鼠的耳部伤口显示软骨和毛囊的再生长。此外，在心脏右心室冷冻损伤后，我们已经证明愈合发生，没有疤痕，心肌细胞几乎完全替代，并恢复正常功能。我们还证明了耳孔闭合表型受多个遗传位点控制，是一个复杂的数量性状，并受到性别的深刻影响。基于这些观察结果，我们建议使用连锁图谱和基因表达谱的组合来确定调节小鼠再生愈合的基因。近交系MRL小鼠品系来源于LG小鼠品系，LG小鼠品系是唯一显示具有这种再生能力的其他品系。已经构建了LG/J（大）和SM/J（小）小鼠之间的高级互交系（AIL）和大量重组近交（RI）品系，其为我们提供了独特的手段来检查它们的再生愈合，探索它们的表型的全部范围，并绘制这些MRL祖细胞中的再生基因。在这个提议中，一个由四个实验室组成的联盟将进行表型分析、基因分型分析、基因表达研究和体外伤口愈合试验。具体目标是：1.产生500只用于初始QTL定位的LGXSM F2小鼠和1000只用于精细定位的LGXSM AIL小鼠; 2.使用成纤维细胞、内皮细胞和角质形成细胞对耳孔闭合进行亚表型分析并分析体外伤口愈合; 3.通过比较显示不同愈合特性的细胞和耳组织来研究基因表达。虽然这些具体目标是协同的，但可以相互独立地实现，以提供重要的信息。我们使用定义明确的LGXSM小鼠资源进行再生愈合的研究使我们能够实现这种遗传强大和独特的愈合模型系统的巨大潜力。

DESCRIPTION (provided by applicant): Wound and tissue injuries are common medical problems that often lead to excessive scar formation and subsequent loss of organ function without normal tissue replacement. Understanding the molecules that control scarless regenerative healing can provide a means to modulate healing and mitigate these significant threats to public health. We have demonstrated previously that adult MRL mice show unique scarless and regenerative-type healing. In these mice, through-and-through ear hole wounds close completely, whereas those in other mice scar. Ear wounds of MRL mice display re-growth of cartilage and hair follicles. In addition, following cryoinjury to the right ventricle of the heart, we have shown healing occurs without scarring, with nearly complete replacement of cardiomyocytes, and with return to normal function. We have also demonstrated that the ear hole closure phenotype is controlled by multiple genetic loci, is a complex quantitative trait, and is profoundly influenced by sex. Based on these observations, we propose to identify the genes that regulate regenerative healing in mice using a combination of linkage mapping and gene expression profiling. The inbred MRL mouse strain derives from the LG mouse strain, which is the only other strain shown to have this regenerative capacity. An advanced intercross line (AIL) and a large panel of recombinant inbred (Rl) strains between LG/J (Large) and SM/J (Small) mice has been constructed that provides us the unique means to examine their regenerative healing, to explore the full range of their phenotypes, and to map the regeneration genes in these MRL progenitors. In this proposal, a consortium of four, laboratories will carry out phenotyping, genotyping, gene expression studies, and in vitro wound healing assays. The specific aims are: 1. Generating 500 LGXSM F2 mice for initial QTL mapping and 1000 LGXSM AIL for fine mapping; 2. Sub-phenotyping ear hole closure and analyzing in vitro wound healing using fibroblasts, endothelial cells, and keratinocytes; 3. Studying gene expression by comparing cells and ear tissue that display differential healing properties. Although synergistic, these specific aims can be accomplished independently of each other to provide significant information. Our study of regenerative healing using the well-defined LGXSM mouse resource enables us to realize the promising potential of this genetically powerful and unique healing model system.