张力预处理ASCs通过M-CSF调控巨噬细胞极化治疗难愈性创面的机制研究

脂肪干细胞ASCs可治疗难愈性创面，但移植效率低下，限制其临床应用。目前认为，导致难愈性创面的主要因素是以M1/M2型巨噬细胞极化失衡为特征的慢性炎症，将M1促炎型诱导为M2抗炎型是有效治疗途径。申请人前期发现，张力预处理显著促进ASCs增殖、迁移，抑制凋亡，提示其可提高细胞移植效率（JCMM，2019）。申请人进一步发现，张力预处理ASCs分泌M-CSF显著增加，且M-CSF是经典的M2型巨噬细胞诱导因子。据此提出：张力预处理ASCs通过上调M-CSF表达，诱导M2型巨噬细胞极化，缓解慢性炎症，促进难愈性创面愈合。拟构建难愈性创面动物模型，完成张力预处理ASCs移植的有效性评价；以巨噬细胞极化失衡为切入点，从体内外水平明确张力预处理ASCs对M2型巨噬细胞极化的诱导及潜在机制；并通过CRISPR/Cas9技术，验证M-CSF在其中的重要介导作用，为临床新方法的建立提供治疗思路和理论依据。

Adipose stem cells (ASCs) could improve impaired wound healing, but the low efficiency of ASCs transplantation limits its clinical application. At present, it is believed that the main factor leading to impaired wound healing is chronic inflammation characterized by the polarization imbalance of M1/M2 macrophages, and the induction of M1 pro-inflammatory type into M2 anti-inflammatory type is the key to its treatment. The applicant has previously reported that mechanical stretch significantly promoted the proliferation and migration of ASCs and inhibited cellular apoptosis, suggesting that it can be used to improve transplantation efficiency (JCMM, 2019). Pre-experiments showed that the mechanical stretch preconditioned significantly increased the M-CSF released from ASCs, and M-CSF was a classical M2 type macrophage inducing factor. Therefore, we suppose that mechanical stretch preconditioned ASCs induces macrophage M2 polarization by up-regulating M-CSF expression, alleviates chronic inflammation, and promotes healing of impaired wound. A mouse model of impaired wound healing was developed to evaluate the therapeutic effect of mechanical stretch preconditioned ASCs. Based on the imbalance of macrophage polarization, the induction effect of mechanical stretch preconditioned ASCs on macrophage M2 polarization and its potential mechanism were investigated in vitro and in vivo. The mediating effect of M-CSF was verified by CRISPR/Cas9 knockout technology, providing treatment thoughts and theoretical basis for clinical application.