慢性伤口发病机制复杂，目前尚缺乏有效的治疗手段。已有研究表明，多种miRNA以高度协调的方式参与伤口愈合的各个阶段，前期工作发现，miR-31可通过上皮膜蛋白EMP-1促进角质形成细胞迁移，增生；miR-132通过HB-EGF抑制NF-κB，活化STAT3、ERK通路促进角质形成细胞增生，促进伤口炎症期向增殖期转化。但miRNA在伤口愈合中的作用仍存在许多未知，如miRNA在人正常的伤口愈合中的动态变化及正常miRNA组是否在慢性伤口中存在失调等。为深入研究慢性伤口愈合相关的miRNA及其功能，本课题研究内容包括：通过急、慢性伤口miRNA芯片谱差异，筛选目标miRNA，并确定其细胞来源；体外体内水平研究目标miRNA 在慢性伤口愈合中的关键生物学功能；确定与伤口愈合相关的miRNAs调控的新靶点；利用3-D 人皮肤伤口模型、人伤口体外模型、小鼠伤口愈合模型确定目标miRNA作为潜在治疗剂的疗效。本研究可明确慢性伤口愈合中起关键作用的miRNA及其调控机制，明确miRNA对慢性伤口愈合的治疗潜力，有望为慢性伤口的靶向治疗提供新的理论和实验基础。

The unclear pathogenesis of nonhealing chronic wounds impedes the development of effective treatment strategies. Accumulating evidence indicates that miRNAs play a key role in regulating several hubs that orchestrate the wound healing. Our research before revealed that miR-31 promoted skin wound healing by enhancing keratinocyte proliferation and migration through upregulation of epithelial membrane protein 1 (EMP-1). MiR-132 promoted keratinocyte proliferation by suppressing the NF-κB pathway and increasing activity of the STAT3 and ERK pathways, and enhanced transition from inflammation to proliferation during wound healing. However there is still much to be discovered about miRNA in wound healing, such as the dynamic change of miRNA in normal wound healing and whether there is dysregulation of miRNAome in chronic wound. The aim of this study is to further identify a candidate set of miRNAs targeting gene expression important for chronic wound healing. MiRNA expression profiles (miRNAome) of injured human skin biopsies are first screened during normal wound healing process and in chronic wounds. A bioinformatics approach is applied to identify differentially-expressed miRNAs and their target genes implicated in wound healing. The therapeutic potentials of miRNAs are determined in vitro with primary keratinocyte wound healing model and in vivo with 3D human skin equivalent wound model , human ex vivo wound model and mouse wound healing model through regulation of miRNA expression affecting the wound healing process. This study will identify the key miRNAs and their regulatory mechanism during chronic wound healing, and more importantly, offer us new potential molecular markers and targets for therapeutic intervention of chronic wound.

慢性伤口发病机制复杂，是目前世界范围内主要的健康和经济负担，目前尚缺乏有效的治疗手段。研究表明，MiRNA以高度协调的方式参与伤口愈合的各个阶段。为深入研究慢性伤口愈合相关的miRNA及其功能，本课题通过急、慢性伤口miRNA芯片谱差异，筛选出miR-132和miR-17~92，体外体内水平研究目标miRNA在慢性伤口愈合中的关键生物学功能，确定其调控的靶点，并利用3-D人皮肤伤口模型、人伤口体外模型、小鼠伤口愈合模型确定目标miRNA作为潜在治疗剂的疗效。我们发现，（1）糖尿病足部溃疡（DFU）中 的表达明显降低，瘦素缺陷的糖尿病（db/db）小鼠伤口中miR-132的表达较野生型小鼠也明显降低。db/db小鼠伤口局部外用miR-132可以促进伤口愈合，促进伤口边缘角质形成细胞增殖并减轻炎症，全转录组分析证实，miR-132 调控体内多种炎症相关信号通路，如NF-ΚB、NOD样受体，Toll样受体，TNF信号通路。miR-132 与尼克F-127凝胶混合外用于体外皮肤伤口模型可以促进上皮重塑。MiR-132对慢性伤口有治疗潜力。（2）MiR-17~92是抑制表皮角质形成细胞炎症反应的主要调控因子。人类静脉溃疡或DFU伤口边缘角质形成细胞中miR-17~92的表达较正常手术伤口明显减少。特异性敲除角质形成细胞中miR-17~92的小鼠的伤口愈合延迟，炎症反应增强，在糖尿病状态下则更加严重。糖尿病小鼠伤口局部外用miR-19b和miR-20a则能促进伤口愈合。治疗慢性伤口的生长因子PDGF-BB可上调角质形成细胞miR-19a/b和miR-20a的表达，这些miRNAs通过协同调节TLR3信号通路抑制角质形成细胞炎症反应。MiR-19a/b通过靶向结合SHCBP1抑制ERK和NF-κB信号活化，而miR-20a通过靶向miR-132结合SEMA7A因子ERK、NF-κB及p38信号通路。MiR-17~92是伤口炎症的负调控因子，在伤口愈合中发挥关键作用。本研究证实了miR-132和miR-17~92促进慢性伤口愈合的调控机制及其治疗潜力，为慢性伤口的靶向治疗提供了新的理论基础。MiR-132和miR-17~92治疗慢性伤口有光明的前景，可行临床对照试验进一步验证。