Department of Plastic Surgery, Zhongshan Hospital, Fudan University, Shanghai 200032, PR China.
Centre for Precision Health, School of Medical and Health Sciences, Edith Cowan University, Joondalup 6027, Australia.
Burns. 2022 Dec;48(8):1893-1908. doi: 10.1016/j.burns.2021.12.010. Epub 2022 Jan 3.
Adipose-derived mesenchymal stem cells (adMSCs) are suggested as potential tools for the treatment of regenerative diseases, including tissue repair. This study aimed to explore the function of adMSC-derived apoptotic bodies in skin wound healing and the molecules of action.
The acquired adMSCs and their-derived apoptotic bodies were identified. A murine model of full-thickness skin wounds was treated with apoptotic bodies. The wound healing process of mice and the pathological changes in wound tissues were examined. Ana-1 macrophages were treated with lipopolysaccharide (LPS) and apoptotic bodies for in vitro experiments. Polarization of macrophages was examined by immunofluorescence staining of the specific biomarkers and ELISA kits. Dermal microvascular endothelial cells (DMECs) or dermal fibroblasts (DFs) were co-cultured with apoptotic bodies or the LPS- and apoptotic bodies-treated Ana-1 cells. Downstream molecules mediated by apoptotic bodies were screened by microarray and bioinformatic analyses.
Apoptotic bodies treatment accelerated skin wound healing in mice and promoted formation of granulation tissues and blood vessels in wound tissues. Apoptotic bodies treatment induced M2 polarization of macrophages. The angiogenesis ability of DMECs, and the viability and migration of DFs were increased when co-cultured with the apoptotic bodies-treated Ana-1 cells. MicroRNA (miR)-21-5p was abundantly expressed in ABs, and kruppel like factor 6 (KLF6) mRNA was confirmed as a target of miR-21-5p. Overexpression of KLF6 reduced M2 polarization of macrophages and blocked the promoting effect of apoptotic bodies on wound healing in vitro and in vivo.
miR-21-5p carried by adMSC-derived apoptotic bodies targets KLF6 to induce M2 polarization of macrophages and augment skin wound healing.
脂肪间充质干细胞（adMSCs）被认为是治疗再生疾病（包括组织修复）的潜在工具。本研究旨在探索 adMSC 来源的凋亡小体在皮肤伤口愈合中的作用机制和相关分子。
鉴定获得的 adMSCs 及其来源的凋亡小体。采用全层皮肤伤口小鼠模型，用凋亡小体处理。观察小鼠伤口愈合过程和伤口组织的病理变化。用脂多糖（LPS）和凋亡小体处理 Ana-1 巨噬细胞进行体外实验。通过免疫荧光染色特异性生物标志物和 ELISA 试剂盒检测巨噬细胞的极化。将凋亡小体或 LPS 和凋亡小体处理的 Ana-1 细胞与真皮微血管内皮细胞（DMECs）或真皮成纤维细胞（DFs）共培养。通过微阵列和生物信息学分析筛选凋亡小体介导的下游分子。
凋亡小体处理加速了小鼠皮肤伤口愈合，并促进了伤口组织中肉芽组织和血管的形成。凋亡小体处理诱导巨噬细胞向 M2 极化。与凋亡小体处理的 Ana-1 细胞共培养后，DMEC 的血管生成能力以及 DF 的活力和迁移均增加。凋亡小体中富含 microRNA（miR）-21-5p，且 kruppel 样因子 6（KLF6）mRNA 被证实是 miR-21-5p 的靶标。KLF6 的过表达降低了巨噬细胞的 M2 极化，并阻断了凋亡小体在体外和体内对伤口愈合的促进作用。
adMSC 来源的凋亡小体携带的 miR-21-5p 通过靶向 KLF6 诱导巨噬细胞 M2 极化，从而增强皮肤伤口愈合。
