Umbilical cord mesenchymal stem cell-derived exosomes ameliorate HaCaT cell photo-aging.

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 effective reduce skin aging, but few studies have specifically focused on the role of UCMSC-derived exosomes in this context. In the present study, we isolated exosomes derived from UCMSCs grown in a 3D culture system and explored their ability to modulate the photo-aging of HaCaT keratinocytes. Cell viability and proliferation was assessed via CCK8 assay, whereas wound healing and transwell assays were used to assess cell migratory capabilities. UVB irradiation (60mJ/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, while qPCR 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.