生前伤和死后伤的鉴别是法医学鉴定工作的重要内容之一。但在实际鉴定过程中，特别是伤后短时间内发生死亡时，法医学传统的肉眼和组织学所能观察到的生活反应有时并不明显，因此缺乏有诊断价值的形态学改变来鉴别生前伤和死后伤。我们前期建立了小鼠皮肤挫伤和烧伤模型，发现多种功能分类和信号通路参与到损伤过程当中。通过对皮肤挫伤和烧伤后功能分类和信号通路比对分析，我们发现皮肤对两种损伤的反应并不一致，提示机体对不同损伤的反应并不相同。本研究拟建立几种常见的小鼠皮肤损伤模型，使用mRNA和RNA测序技术，筛选出损伤早期差异表达的mRNA和microRNA，用生物信息学方法对结果进行分析，探索其生物学功能，并观察不同死后时间对所选指标的影响，最后使用法医尸体解剖相应损伤的皮肤组织进行验证。从而筛选出能实际应用于法医学生前、死后伤鉴别的生物学指标，服务于法医实际鉴定工作。

To discriminate ante-mortem wounds from postmortem damage is one of the most important issues in forensic examinations. However, it is sometimes difficult to discriminate ante-mortem wounds from postmortem damage in forensic practices, because of the lack of macroscopic objective evidence, especially when the wounds are inflicted very close to the time of death. Our preliminary studies, using experimental models of contusion and burn, showed that, diverse functional categories and signaling pathways were involved in the process. However, genes from different functional categories and signaling pathways were enriched, indicating different kinds of injury evoke different responses. In the present study, we will make several models of injury, by using mRNA and small RNA sequence, to screen for differentially expressed mRNAs and microRNAs. Then we will use bioinformatics analysis to clarify the biological functions of those markers. The effects of postmortem intervals on selected mRNAs and microRNAs will also be evaluated. Finally, we will postmortem human skin tissues to validate these potential markers. The aims of the proposal are to reveal reliable markers to distinguish ante-mortem from post-mortem wounds and to serve forensic practice.