Abstract：
Diabetic patients often experience impaired wound healing. Human cathelicidin LL-37 possesses various biological functions, such as anti-microbial, anti-inflammatory, and pro-wound healing activities. Autophagy has important effects on skin wound healing. However, little is known about whether LL-37 accelerates diabetic wound healing by regulating autophagy. In the study, we aimed to investigate the role of autophagy in LL-37-induced wound healing and uncover the underlying mechanisms involved. A full-thickness wound closure model was established in diabetic mice to evaluate the effects of LL-37 and an autophagy inhibitor (3-MA) on wound healing. The roles of LL-37 and 3-MA in regulating keratinocyte migration were assessed using transwell migration and wound healing assays. The activation of transcription factor EB (TFEB) was measured using western blotting and immunofluorescence (IF) assays of its nuclear translocation. The results showed that LL-37 treatment improved wound healing in diabetic mice, whereas these effects were reversed by 3-MA. In vitro, 3-MA decreased the effects of LL-37 on promoting HaCat keratinocyte migration in the presence of high glucose (HG). Mechanistically, LL-37 promoted TFEB activation and resulted in subsequent activation of autophagy, as evidenced by increased nuclear translocation of TFEB and increased expression of ATG5, ATG7, and beclin 1 (BECN1), whereas these changes were blocked by TFEB knockdown. As expected, TFEB knockdown damaged the effects of LL-37 on promoting keratinocyte migration. Collectively, these results suggest that LL-37 accelerates wound healing in diabetic mice by activating TFEB-dependent autophagy, providing new insights into the mechanism by which LL-37 promotes diabetic wound healing.
摘要：
糖尿病患者经常经历受损的伤口愈合。人cathelicidinLL-37具有多种生物学功能，如抗微生物，抗炎,和促进伤口愈合的活动。自噬对皮肤创面愈合有重要影响。然而,关于LL-37是否通过调节自噬来加速糖尿病伤口愈合知之甚少。在研究中,我们旨在研究自噬在LL-37诱导的伤口愈合中的作用,并揭示其相关机制.在糖尿病小鼠中建立了全层伤口闭合模型，以评估LL-37和自噬抑制剂（3-MA）对伤口愈合的影响。使用transwell迁移和伤口愈合测定法评估了LL-37和3-MA在调节角质形成细胞迁移中的作用。使用蛋白质印迹和免疫荧光（IF）测定其核易位来测量转录因子EB（TFEB）的激活。结果表明，LL-37治疗改善了糖尿病小鼠的伤口愈合，而这些效应被3-MA逆转。体外，3-MA降低了LL-37在高葡萄糖（HG）存在下促进HaCat角质形成细胞迁移的作用。机械上,LL-37促进TFEB激活并导致随后的自噬激活，如TFEB的核易位增加和ATG5，ATG7和beclin1（BECN1）的表达增加所证明的，而这些变化被TFEB敲低阻断。不出所料,TFEB敲低破坏了LL-37促进角质形成细胞迁移的作用。总的来说，这些结果表明，LL-37通过激活TFEB依赖性自噬加速糖尿病小鼠的伤口愈合，为LL-37促进糖尿病伤口愈合的机制提供了新的见解。
