DefinePK

Abstract

ABSTRACT This study aims at measuring expressions of β-catenin and senescence marker protein-30 (SMP30) after normal human skin fibroblasts (NHSFs) irradiated by different UVB doses as well as durations, thus unveiling mechanisms underlying HSF senescence induced by Ultraviolet B (UVB). NHSFs treated under different doses (100, 200, 300 mJ/cm2) of UVB with different durations (1, 2, 3 days) were case group, while those without UVB irradiation were control group. Expressions of gene/protein were obtained with real-time quantitative PCR (RT-qPCR) and western blot; cell proliferation inhibition rates (CPIR) of HSF were obtained by MTT, and HSF apoptosis was detected using Flow Cytometry (FCM). UVB irradiations significantly inhibit HSF growth, showing positive correlation with the increasing of CPIRs and apoptotic rates; The relative expression levels of β-catenin and Senescence marker protein-30 (SMP30) gene in UVB treated group were significantly lower than that of the control group; Gene expression levels also varied with different UVB doses and durations, indicating statistically significant dose- and time-dependent effects of UVB. UVB treatments inhibit cell growth and promote apoptosis in a dose-dependent and time-dependent manner, and high level as well as prolonged UVB irradiation lead to NHSFs senescence.