Abstract
Umbilical cord mesenchymal stem cells (UCMSCs) have been identified as a potentially ideal cell type for use in regenerative therapeutic contexts owing to their excellent paracrine secretory abilities and other desirable properties. Previous work has shown that stem cell-derived exosomes can effectively reduce skin aging, but few studies have specifically focused on the role of UCMSC-derived exosomes in this context. In this study, we isolated exosomes derived from UCMSCs grown in a three-dimensional culture system and explored their ability to modulate the photo-aging of HaCaT keratinocytes. Cell viability and proliferation were assessed using CCK8 assay, whereas wound healing and transwell assays were used to assess cell migratory capabilities. UVB irradiation (60 mJ/cm2) was used to induce photo-aging of HaCaT cells. TUNEL and SA-β-Gal staining were used to explore HaCaT cell apoptosis and senescence, respectively, whereas real-time quantitative PCR was used to assess the expression of relevant genes at the mRNA level. We found that UCMSC-derived exosomes were able to enhance normal HaCaT cell proliferation and migration while also inhibiting UVB-induced damage to these cells. These exosomes also reduced HaCaT cell apoptosis and senescence, increasing collagen type I expression and reducing matrix metalloproteinase (MMP1) expression in photo-aged HaCaT cells. Together, these findings indicate that UCMSC-derived exosomes have the potential to be used therapeutically to suppress skin aging.