Background Adipose mesenchymal stem cell-derived exosomes (ADSC-Exos) have great potential in the field of tissue repair and regenerative medicine, particularly in cases of refractory diabetic wounds. Interestingly, autophagy plays a role in wound healing, and recent research has demonstrated that exosomes are closely associated with intracellular autophagy in biogenesis and molecular signaling mechanisms. Therefore, this study aimed to investigate whether ADSC-Exos promote the repair of diabetic wounds by regulating autophagy to provide a new method and theoretical basis for the treatment of diabetic wounds. Methods Western blot analysis and autophagy double-labelled adenovirus were used to monitor changes in autophagy flow in human immortalized keratinocyte cell line (HaCaT) cells. ADSC-Exos were generated from ADSC supernatants via ultracentrifugation. The effectiveness of ADSC-Exos on HaCaT cells was assessed using a live-cell imaging system, cell counting kit-8 and cell scratch assays. The cells were treated with the autophagy inhibitor bafilomycin A1 to evaluate the effects of autophagy on cell function. The recovery of diabetic wounds after ADSC-Exo treatment was determined by calculating the healing rates and performing histological analysis. High-throughput transcriptome sequencing was used to analyze changes in mRNA expression after the treatment of HaCaT cells with ADSC-Exos. Results ADSC-Exos activated autophagy in HaCaT cells, which was inhibited by high glucose levels, and potentiated their cellular functions. Moreover, ADSC-Exos in combination with the autophagy inhibitor bafilomycin A1 showed that autophagy defects further impaired the biological function of epidermal cells under high-glucose conditions and partially weakened the healing effect of ADSC-Exos. Using a diabetes wound model, we found that ADSC-Exos promoted skin wound healing in diabetic mice, as evidenced by increased epidermal autophagy and rapid re-epithelialization. Finally, sequencing results showed that increased expression of autophagy-related genes nicotinamide phosphoribosyltransferase (NAMPT), CD46, vesicle-associated membrane protein 7 (VAMP7), VAMP3 and eukaryotic translation initiation factor 2 subunit alpha (EIF2S1) may contribute to the underlying mechanism of ADSC-Exo action. Conclusions This study elucidated the molecular mechanism through which ADCS-Exos regulate autophagy in skin epithelial cells, thereby providing a new theoretical basis for the treatment and repair of skin epithelial damage by ADSC-Exos.

中文翻译：

---

脂肪间充质干细胞来源的外泌体通过调节表皮自噬促进糖尿病小鼠皮肤伤口愈合

背景脂肪间充质干细胞衍生的外泌体（ADSC-Exos）在组织修复和再生医学领域具有巨大潜力，特别是在难治性糖尿病伤口的情况下。有趣的是，自噬在伤口愈合中发挥着重要作用，最近的研究表明，外泌体在生物发生和分子信号传导机制中与细胞内自噬密切相关。因此，本研究旨在探讨ADSC-Exos是否通过调节自噬促进糖尿病创面的修复，为糖尿病创面的治疗提供新的方法和理论依据。方法采用Western blot分析和自噬双标腺病毒检测人永生化角质形成细胞系（HaCaT）细胞自噬流的变化。ADSC-Exos 是通过超速离心从 ADSC 上清液中产生的。使用活细胞成像系统、细胞计数试剂盒 8 和细胞划痕测定评估 ADSC-Exos 对 HaCaT 细胞的有效性。用自噬抑制剂巴弗洛霉素 A1 处理细胞，以评估自噬对细胞功能的影响。通过计算愈合率并进行组织学分析来确定 ADSC-Exo 治疗后糖尿病伤口的恢复情况。采用高通量转录组测序分析ADSC-Exos处理HaCaT细胞后mRNA表达的变化。结果 ADSC-Exos 激活 HaCaT 细胞中被高葡萄糖水平抑制的自噬，并增强其细胞功能。此外，ADSC-Exos与自噬抑制剂巴弗洛霉素A1联合显示，自噬缺陷进一步损害了高糖条件下表皮细胞的生物学功能，并部分削弱了ADSC-Exos的愈合效果。使用糖尿病伤口模型，我们发现 ADSC-Exos 促进糖尿病小鼠的皮肤伤口愈合，表皮自噬增加和快速上皮再生就证明了这一点。最后，测序结果表明，自噬相关基因烟酰胺磷酸核糖转移酶（NAMPT）、CD46、囊泡相关膜蛋白7（VAMP7）、VAMP3和真核翻译起始因子2亚基α（EIF2S1）表达的增加可能有助于自噬的潜在机制。 ADSC-Exo 作用。结论 本研究阐明了ADCS-Exos调节皮肤上皮细胞自噬的分子机制，为ADSC-Exos治疗和修复皮肤上皮损伤提供新的理论依据。