Background. Human dermal fibroblasts (HDFs) are the primary cells in skin and are associated with UVB-induced skin photoaging. Adipose-derived stem cells (ASCs) have been proposed as a treatment for skin aging. The goal of this study was to investigate paracrine mechanisms by which ASCs repair HDFs damage from UVB exposure. Methods. ASCs were cocultured with UVB-irradiated and nonirradiated HDFs. We compared HDF senescence, proliferation, migration, oxidative stress, and cytokine expression. In a nude mouse UVB-induced photoaging model, ASCs were injected subcutaneously, and skin samples were collected weekly between postoperative weeks 3 through 7. Histological analysis, PCR, ELISA, and immunohistochemistry were used to analyze the effect of ASCs. Results. Compared with UVB-irradiated HDFs, nonirradiated HDFs showed higher proliferation and migration, reduced apoptosis, and fewer senescent cells when cocultured with ASCs. The expression of extracellular matrix-related cytokines was also regulated by ASCs. In addition, ASCs effectively reversed UVB-induced skin photoaging in vivo. We propose that ASCs more robustly coordinate healthy HDFs than UVB-damaged HDFs to repair aging skin. Conclusions. ASCs improved the function of both UVB-damaged and healthy HDFs through paracrine effects. However, the impact of ASCs on healthy HDFs was greater than UVB-damaged HDFs. These findings help to elucidate the underlying mechanisms of the skin rejuvenation effect of ASCs.

中文翻译：

---

脂肪源性干细胞的旁分泌作用协调不同受损真皮成纤维细胞之间的竞争以修复 UVB 诱导的皮肤老化

背景。人类真皮成纤维细胞 (HDF) 是皮肤中的主要细胞，与 UVB 诱导的皮肤光老化有关。脂肪源性干细胞 (ASCs) 已被提议作为皮肤老化的治疗方法。本研究的目的是研究 ASC 修复 UVB 暴露造成的 HDF 损伤的旁分泌机制。方法。ASC 与 UVB 照射和未照射的 HDF 共培养。我们比较了 HDF 的衰老、增殖、迁移、氧化应激和细胞因子表达。在裸鼠 UVB 诱导的光老化模型中，皮下注射 ASC，并在术后第 3 周至第 7 周之间每周收集皮肤样本。组织学分析、PCR、ELISA 和免疫组织化学用于分析 ASC 的作用。结果. 与 UVB 照射的 HDFs 相比，未照射的 HDFs 在与 ASCs 共培养时表现出更高的增殖和迁移、减少的细胞凋亡和更少的衰老细胞。细胞外基质相关细胞因子的表达也受 ASC 的调节。此外，ASCs 在体内有效地逆转了 UVB 诱导的皮肤光老化。我们建议 ASCs 比 UVB 损伤的 HDFs 更强大地协调健康的 HDFs 来修复老化的皮肤。结论。ASC 通过旁分泌作用改善了 UVB 损伤和健康 HDF 的功能。然而，ASCs 对健康 HDFs 的影响大于 UVB 损伤的 HDFs。这些发现有助于阐明 ASC 的皮肤年轻化作用的潜在机制。