基于新型微流控小室探究Herpud1介导的极化巨噬细胞影响皮肤损伤修复的细胞和分子机制

Macrophage polarization is crucial in skin wound healing process, but the underlying mechanism remains largely unclear. Here we originally defined that Herpud1 both positively regulated skin repair in mice model and ERS-dependently promoted M2 macrophage polarization based on our previous project of National Natural Science Foundation of China (31401191). Combined with the data that Herpud1 up-regulated CHOP, the key regulator of UPR signaling pathway, these results implied that Herpud1 might positively control macrophage polarization via UPR-CHOP pathway and further impacted skin repair. In basis of the previous data and the advantages of microfluidic chamber, we are going to establish a microfluidic chamber, an innovative cell-culture system for skin wound healing analysis in vitro and use it to research how Herpud1 is involved in the process that polarized macrophage influence skin innate cell proliferation, migration and their interaction (paracrine/direct interaction). Based on these, the underlying mechanism is to be clarified about how Herpud1 modulates macrophage polarization through three UPR signaling pathways. In vivo, it is going to be explored that Herpud1 accelerates skin wound repair by increasing macrophage polarization in skin-wound mice model. Together, we aim to illustrate Herpud1 mediates macrophage polarization depending on UPR signaling pathway to facilitate skin repair through experiments in vivo and vitro. Thus, our study is expected to provide a new idea for the research and treatment of skin wound.

巨噬细胞极化在皮肤损伤修复过程中有重要作用，具体机制不清。基于我们自科项目（31401191），首次发现Herpud1促进M2型巨噬细胞极化与内质网应激（ERS）相关。我们预实验进一步证实Herpud1加速小鼠皮肤损伤修复，且上调ERS信号通路UPR关键分子CHOP表达，提示Herpud1可能通过UPR-CHOP介导巨噬细胞极化，促进皮肤损伤修复。鉴于微流控小室高通量、低消耗等优势，本项目拟建立适用于皮肤损伤修复体外分析的创新型细胞培养体系——微流控小室，研究Herpud1介导巨噬细胞极化以调控皮肤固有细胞增殖、迁移和互作（旁分泌和直接作用）；结合皮肤损伤小鼠模型，深入挖掘UPR-CHOP参与Herpud1介导的极化巨噬细胞促进皮肤损伤修复的细胞和分子机制。综上，利用微流控小室-细胞模型和动物模型阐明Herpud1促进皮肤损伤愈合的具体机制，将为皮肤损伤提供研究新工具和治疗新思路。

经过开展课题研究，发现Herpud1促进巨噬细胞向M2型极化，并且Herpud1能够促进M0和M2型巨噬细胞的迁移。证明了Herpud1影响巨噬细胞的内质网应激，且利用内质网应激抑制剂4-PBA处理巨噬细胞，可以抑制其对巨噬细胞极化的影响。成功构建基于气阀控制的微流控小室、基于基质胶的3D培养微流控小室和利用基于基质胶的3D培养微流控小室分析不同极化状态的巨噬细胞对于NIH3T3迁移的影响。该微流控小室为非接触细胞相互作用的研究提供了新平台和新范式。成功设计并构建了一种新型3D细胞培养芯片，模拟创面愈合微环境，证明了M2巨噬细胞对3T3成纤维细胞增值与分化的促进作用，为皮肤损伤修复研究和治疗提供了新工具和新思路。