Mapping Murine Regeneation Genes

描述(申请人提供)：创伤和组织损伤是常见的医学问题，通常会导致过度的疤痕形成和随后的器官功能丧失，而不进行正常的组织置换。了解控制无疤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小鼠表现出独特的无疤痕和再生型愈合。在这些小鼠中，穿透的耳孔伤口完全闭合，而其他小鼠的耳孔伤口则会留下疤痕。MRL小鼠耳部伤口显示软骨和毛囊的再生。此外，在右心室冷冻损伤后，我们发现愈合过程中没有疤痕，几乎完全替换了心肌细胞，并恢复了正常功能。我们还证明了耳孔闭合表型受多个遗传座位控制，是一个复杂的数量性状，并且受性别的影响很大。基于这些观察，我们建议使用连锁图谱和基因表达谱相结合的方法来识别调节小鼠再生愈合的基因。近亲交配的MRL小鼠品系来自LG小鼠品系，这是唯一被证明具有这种再生能力的另一个品系。在LG/J(大)和SM/J(小)小鼠之间构建了一个高级异交系(AIL)和一大组重组近交系(RL)品系，为我们提供了独特的手段来检查它们的再生愈合，探索它们的全部表型，并定位这些MRL祖细胞的再生基因。在这项提议中，一个由四个实验室组成的联盟将进行表型鉴定、基因鉴定、基因表达研究和体外伤口愈合试验。其具体目标是：1.建立500只LGXSM F2小鼠用于初始QTL定位和1000只LGXSM AIL用于精细定位；2.利用成纤维细胞、内皮细胞和角质形成细胞对耳洞闭合进行亚型鉴定，并分析体外伤口愈合情况；3.通过比较具有不同愈合特性的细胞和耳朵组织来研究基因表达。虽然是协同的，但这些具体目标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小鼠资源对再生愈合进行的研究使我们能够实现这一遗传功能强大且独特的愈合模型系统的前景。

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.