Research on the senescence of human skin fibroblasts induced by ultraviolet b and its mechanism

Objective: To discuss the effect of ultraviolet B (UVB) on inducing the senescence of human skin fibroblasts and investigate its mechanism. Methods: The tissue explants method was used to isolate and culture the primary human skin fibroblasts, and after the observation of changes in cell morphology and β-galactosidase (β-gal) cell senescence staining via irradiation with different doses of UVB, the single irradiation dose of UVB in the induction of senescence of skin fibroblasts in subsequent experiment was determined. The cells and supernatant were collected at different time points (12, 24, 48 and 72 h) after irradiation with established doses of UVB. Western blotting was performed to detect the expression of marker P16 protein in induced senescent cells, and the expression of type I collagen, type III collagen, matrix metalloproteinase (MMP)-1 and MMP-3 of senescent cells was detected via ELISA. Results: According to Western blotting analysis, the expression of P16 protein in induced senescent skin fibroblasts was increased with the prolongation of irradiation time of UVB. ELISA showed that the expression of type I and III collagen was significantly reduced with the prolongation of irradiation time of UVB, while the expression of MMP1 and MMP3 was significantly increased. Conclusion: UVB irradiation can induce the senescence of human skin fibroblasts, whose mechanism may be related to the decrease of collagen synthesis and the increase of collagen degradation.