Comparative analysis of genome-wide gene expression profiles in heart, liver, spleen, ears and bone marrow in the murine strains of MRL/MpJ, C57B/6J, and Balb/C

The MRL/MpJ mouse strain is known as a model of mammalian regeneration. The strain exhibits an unusual capacity in regenerative wound healing manifested by scarless ear-hole closure and enhanced regeneration response reported in other organs. A significant feature of the strain is that the adult MRL/MpJ mouse retains several embryonic biochemical characteristics, including increased expression of stem cell markers. As the regenerative response after injury is rather limited in mammals the MRL/MpJ mouse is a great model to study the molecular and cellular basis of scarless wound healing. We report here the analysis of genome-wide transcriptomic profiles in the heart, ear, spleen, liver and bone marrow of the MRL/MpJ mouse. We used gene expression microarray, which interrogates 44.170 of mouse transcripts, in order to identify the genes exhibiting remarkable differences in expression in the MRL/MpJ mouse compared to two reference strains: C57BL/6J and BALB/c. The comparison revealed hundreds of differentially expressed transcripts. Significant enrichments of genes engaged in retinol metabolism, peroxisome proliferator-activated receptor (PPAR), wound healing, and homeobox pathways distinguishes the differentially expressed transcripts up-regulated in the MRL/MpJ mouse, whereas the genes related to immune response, including including response to wounding are greatly enriched among those down-regulated. The same functional categories were associated with remarkable parallels between the transcriptomic patterns in murine neonates and the adult MRL/MpJ mouse. 15 samples, each sample is a poll representing three animalsMRL/MpJ小鼠品系是公认的哺乳动物再生模型。该品系具备非同寻常的再生性伤口愈合能力，具体表现为无疤痕耳孔闭合，以及在其他器官中观测到的增强型再生应答。该品系的核心特征之一为：成年MRL/MpJ小鼠保留了多种胚胎生化特性，其中包括干细胞标志物（stem cell markers）表达水平升高。鉴于哺乳动物损伤后的再生反应普遍较为有限，MRL/MpJ小鼠成为研究无疤痕伤口愈合的分子与细胞基础的理想模型。本研究针对MRL/MpJ小鼠的心脏、耳部、脾脏、肝脏及骨髓开展了全基因组转录组谱（genome-wide transcriptomic profiles）分析。我们采用可检测44170个小鼠转录本的基因表达微阵列（gene expression microarray），以鉴定相较于两个参考品系C57BL/6J与BALB/c，MRL/MpJ小鼠中表达存在显著差异的基因。对比分析共揭示了数百条差异表达转录本。在MRL/MpJ小鼠中上调的差异表达转录本，显著富集于视黄醇代谢、过氧化物酶体增殖物激活受体（peroxisome proliferator-activated receptor, PPAR）、伤口愈合及同源框通路；而在下调的转录本中，与免疫应答相关的基因（包括损伤应答相关基因）则呈现出显著富集现象。小鼠新生个体与成年MRL/MpJ小鼠的转录组模式之间存在显著共通性，且该共通性同样关联于上述功能类别。本研究共纳入15个样本，每个样本均为三只动物的混合样品。