Effects of sirolimus on ultraviolet B irradiation-induced premature senescence of skin fibroblasts
10.3760/cma.j.issn.0412-4030.2013.08.012
- VernacularTitle:自噬促进剂西罗莫司对中波紫外线诱导成纤维细胞提早衰老的影响
- Author:
Xiaobo FANG
;
Bingrong ZHOU
;
Dan LUO
;
Ze GUO
;
Huibin YIN
;
Yanyan HU
- Publication Type:Journal Article
- Keywords:
Fibroblasts;
Cell aging;
Ultraviolet rays;
Sirolimus;
Autophagy
- From:Chinese Journal of Dermatology
2013;46(8):579-582
- CountryChina
- Language:Chinese
-
Abstract:
Objective To observe the effect of sirolimus,an autophagy enhancer,on premature senescence in fibroblasts induced by repeated exposure to a subtoxic dose of ultraviolet B (UVB).Methods Skin fibroblasts from foreskin tissue of healthy adolescents were classified into six groups:control group cultured in Dulbecco's modified Eagles' medium (DMEM) containing 1％ calf serum,UVB group receiving UVB irradiation only,sirolimus group treated with sirolimus of 10 mg/L (added after daily exchange of culture medium),and three combined groups receiving UVB irradiation immediately followed by overnight treatment with sirolimus of 0.1,1.0 and 10.0 mg/L respectively.UVB irradiation was given at a dose of 10 mJ/cm2 once a day for five successive days.After five days of treatment,cell counting kit-8 (CCK-8) was used to evaluate cell viability,β-galactosidase staining to detect senescent ceils,Western blot to quantify the expressions of p53,LC3-B and beclin 1 in these fibroblasts.Autophagy level was determined by acridine orange staining followed by fluorescence microscopy and transmission electron microscopy.Data were processed by the SPSS 16.0 software,and statistical analysis was done by one-way analysis of variance,t test and least significance difference.Results Sirolimus significantly increased the proliferative activity of fibroblasts in a dose-dependent manner,with the absorbance value at 450 nm being 0.27 ± 0.02,0.36 ± 0.04 and 0.39 ± 0.04 for fibroblasts irradiated with UVB followed by treatment with sirolimus of 0.1,1.0 and 10 mg/L respectively,compared to 0.26 + 0.01 for fibroblasts irradiated with UVB only (all P ＜ 0.05).Significant differences were also observed between the fibroblasts irradiated with UVB followed by treatment with sirolimus of 0.1,1.0 and 10 mg/L and those irradiated with UVB only in the percentage of β-galactosidasepositive fibroblasts (92.50％ ± 0.34％,42.40％ ± 0.53％ and 6.20％ ± 0.39％ vs.95.10％ ± 0.32％,all P ＜ 0.05)and intracellular intensity of acridine orange-induced fluorescence (36.43 ± 0.24,45.25 ± 0.33 and 48.69 ± 0.37 vs.33.99 ± 0.32,all P ＜ 0.05).Moreover,the expressions of p53,LC3-B and beclin 1 in the three combined groups differed significantly from those in the UVB group (all P ＜ 0.05).Conclusion Sirolimus can inhibit UVBinduced premature senescence likely via upregulation of autophagy in fibroblasts.
