Effect of miRNA-23a silencing on ultraviolet B-induced chronic photodamage to fibroblasts

Abstract

Objective To evaluate the effect of miRNA-23a silencing on ultraviolet B (UVB)-induced chronic photodamage to fibroblasts.Methods Fibroblasts from human foreskin were divided into four groups:blank control group receiving untreated,UVB group receiving UVB irradiation only,miRNA-23a group transfected with a miRNA-23a antagomir,UVB + miRNA-23a group receiving transfection with miRNA-23a antagomir followed by UVB irradiation.UVB irradiation was carried out once a day for five consecutive days at a dose of 10 mJ/cm2.Three days after the last irradiation,SA-β-galactosidase staining was performed to detect senescent cells,flow cytometry to analyze cell cycle,and real-time PCR and Western blot to measure the mRNA and protein expressions of p53,p16 and p21,respectively.Results Both the percentage of β-galactosidase-positive cells and proportion of G1-phase cells were significantly higher in the UVB group than in the UVB + miRNA-23a group ((94.60 ± 2.58)％ vs.(48.18 ± 3.70)％,(85.06 ± 1.52)％ vs.(57.48 ± 2.01)％,both P＜ 0.05).Significant differences were observed in the mRNA and protein expressions of p53,p16 and p21 between the UVB group and UVB + miRNA-23a group (all P ＜ 0.05).Conclusions The silencing of miRNA-23a may suppress UVB-induced chronic photodamage,which is likely to be associated with the inhibition of senescence-associated downstream signaling molecules. Key words: Ultraviolet rays; Fibroblasts; MicroRNAs; Cell aging