Effects of β-catenin on the proliferative activity of and expressions of two apoptosis-related genes Bcl-2 and Bax by human skin fibroblasts induced by hydrogen peroxide / 中华皮肤科杂志

ABSTRACT

Objective To investigate the effect of highly expressed β-catenin on the proliferative activity of and expressions of two apoptosis-related genes Bcl-2 and Bax by human skin fibroblasts induced by hydrogen peroxide (H2O2).Methods Normal human skin fibroblasts (HSFs) from child foreskin were divided into three groups:empty vector group transfected with the empty vector pcDNA3.1,H2O2 group transfected with the empty vector pcDNA3.1 followed by treatment with H2O2 (150 μ mol/L) for 2 hours,β-catenin group transfected with pcDNA3.1-β-catenin followed by treatment with H2O2 (150 μ mol/L) for 2 hours.Subsequently,methyl thiazolyl tetrazolium (MTT) assay was conducted to estimate proliferative activity of fibroblasts,flow cytometry to detect cell apoptosis,and reverse transcription (RT)-PCR and Western blot were performed to measure the mRNA and protein expressions of Bcl-2 and Bax respectively.The relative expression levels of genes were expressed as the ratios between the targets and GAPDH.Results Significant differences were found between the empty vector group,H2O2 group and β-catenin group in cellular proliferative activity (expressed as absorbance value at 570 nm:0.792 ± 0.012 vs.0.462 ± 0.012 vs.0.521 ± 0.015,P＜ 0.01) and apoptosis rate (3.407％ ± 0.217％ vs.24.555％ ± 1.793％ vs.15.360％ ± 0.755％,P＜ 0.01).Both mRNA and protein expression levels of Bcl-2 were significantly lower in the H2O2 group (0.333 ± 0.003 and 0.336 ± 0.004 respectively) than in the empty vector group (0.507 ± 0.013 and 0.514 ± 0.021,respectively,both P ＜ 0.01) and β-catenin group (0.404 ± 0.006 and 0.411 ± 0.005,respectively,both P ＜ 0.01).Increased expression levels of Bax mRNA and protein were observed in the H2O2 group compared with the empty vector group and β-catenin group (mRNA:0.451 ± 0.002 vs.0.303 ± 0.005 and 0.339 ± 0.012,protein:0.460 ± 0.008 vs.0.320 ± 0.013 and 0.346 ± 0.013,all P＜ 0.01).Conclusion High expression of β-catenin can raise proliferative activity of aging HSFs.