Abstract：
Hypoxic preconditioning has been recognized as a promotive factor for accelerating cutaneous wound healing. Our previous study uncovered that exosomal lncRNA H19, derived from adipose-derived stem cells (ADSCs), plays a crucial role in orchestrating cutaneous wound healing. Herein, we aimed to explore whether there is a connection between hypoxia and ADSC-derived exosomes (ADSCs-exos) in cutaneous wound healing. Exosomes extracted from ADSCs under normoxic and hypoxic conditions were identified using transmission electron microscope (TEM) and particle size analysis. The effects of ADSCs-exos on the proliferation, migration, and angiogenesis of human umbilical vein endothelial cells (HUVECs) were evaluated by CCK-8, EdU, wound healing, and tube formation assays. Expression patterns of H19, HIF-1α, and USP22 were measured. Co-immunoprecipitation, chromatin immunoprecipitation, ubiquitination, and luciferase reporter assays were conducted to confirm the USP22/HIF-1α/H19 axis, which was further validated in a mice model of skin wound. Exosomes extracted from hypoxia-treated ADSCs (termed as H-ADSCs-exos) significantly increased cell proliferation, migration, and angiogenesis in H2O2-exposed HUVECs, and promoted cutaneous wound healing in vivo. Moreover, H-ADSCs and H-ADSCs-exos, which exhibited higher levels of H19, were found to be transcriptionally activated by HIF-1α. Mechanically, H-ADSCs carrying USP22 accounted for deubiquitinating and stabilizing HIF-1α. Additionally, H-ADSCs-exos improved cell proliferation, migration, and angiogenesis in H2O2-triggered HUVECs by activating USP22/HIF-1α axis and promoting H19 expression, which may provide a new clue for the clinical treatment of cutaneous wound healing.
摘要：
低氧预处理已被认为是加速皮肤伤口愈合的促进因素。我们之前的研究发现，外泌体lncRNAH19，来自脂肪干细胞（ADSCs），在协调皮肤伤口愈合中起着至关重要的作用。在这里，我们旨在探讨缺氧与ADSC来源的外泌体(ADSC-exos)在皮肤伤口愈合中是否存在联系.使用透射电子显微镜(TEM)和粒度分析鉴定在常氧和低氧条件下从ADSC提取的外泌体。ADSCs-exos对细胞增殖的影响,迁移,用CCK-8、EdU、伤口愈合，和试管形成测定。H19、HIF-1α的表达模式,和USP22进行测量。免疫共沉淀,染色质免疫沉淀，泛素化，和荧光素酶报告基因测定进行确认USP22/HIF-1α/H19轴，在小鼠皮肤创伤模型中进一步验证。从缺氧处理的ADSCs中提取的外泌体（称为H-ADSCs-exos）显着增加细胞增殖，迁移,和H2O2暴露的HUVECs中的血管生成，并促进体内皮肤伤口愈合。此外，H-ADSCs和H-ADSCs-exos,H19水平较高，被发现被HIF-1α转录激活。机械上,携带USP22的H-ADSCs可导致去泛素化和稳定HIF-1α。此外,H-ADSCs-exos促进细胞增殖，迁移,通过激活USP22/HIF-1α轴并促进H19表达，在H2O2触发的HUVECs中血管生成，为临床治疗皮肤创面愈合提供新的线索。
