Human amnion-derived mesenchymal stem cells protect against UVA irradiation-induced human dermal fibroblast senescence, in vitro.

The aim of the present study was to determine if human amnion‑derived mesenchymal stem cells (HAMSCs) exert a protective effect on ultraviolet A (UVA) irradiation-induced human dermal fibroblast (HDF) senescence. A senescence model was constructed as follows: HDFs (104‑106 cells/well) were cultured in a six‑well plate in vitro and then exposed to UVA irradiation at 9 J/cm2 for 30 min. Following the irradiation period, HDFs were co‑cultured with HAMSCs, which were seeded on transwells. A total of 72 h following the co‑culturing, senescence‑associated β‑galactosidase staining was performed and reactive oxygen species (ROS) content and mitochondrial membrane potential (Δψm) were detected in the HDFs via flow cytometric analysis. The results demonstrated that the percentage of HDFs, detected via staining with X‑gal, were markedly decreased when co‑cultured with human HAMSCs, compared with the group that were not co‑cultured. The ROS content was decreased and the mitochondrial membrane potential (Δψm) recovered in cells treated with UVA and HAMSCs, compared with that of cells treated with UVA alone. Reverse transcription‑quantitative polymerase chain reaction revealed the significant effects of HAMSCs on the HDF senescence marker genes p53 and matrix metalloproteinase‑1 mRNA expression. In addition to this, western blot analysis verified the effects of HAMSCs on UVA induced senescence, providing a foundation for novel regenerative therapeutic methods. Furthermore, the results suggested that activation of the extracellular‑signal regulated kinase 1/2 mitogen activated protein kinase signal transduction pathway, is essential for the HAMSC‑mediated UVA protective effects. The decrease in ROS content additionally indicated that HAMSCs may exhibit the potential to treat oxidative stress‑mediated UVA skin senescence in the future.