Effects Of UVB On Skin Fibroblasts And Its Mechanism

Objective: 1.To study the effect of UVB on skin fibroblasts and the potential medicinal value of Salubrinal against UVB irradiation.2.To investigate the mechanism of Salubrinal in skin fibroblasts death caused by UVB irradiation.Method: 1.Effects of UVB irradiation on skin fibroblasts and the effects of Salubrinal on UVB-induced skin fibroblast death: human foreskin fibroblasts(BJ cells)which were in vitro cultured were divided into four groups.The control group,the group treated with Salubrinal.,the group were pretreated with Salubrinal before UVB-irradiated,and UVB-irradiated groups.The proliferation and survival of the cells were detected by MTT method and trypan blue test.2.The effects of salubrinal on the death of skin fibroblasts induced by UVB irradiation were performed using in vitro cultured human foreskin fibroblasts(BJ cells),which were divided into experimental group and control group.The experimental group was pretreated with Salubrinal and the control group was not treated.Then,they were irradiated with 5 different intensity UVBs respectively,and cell proliferation and survival were detected by MTT assay.3.Salubrinal effective dose determination: human foreskin fibroblasts cultured in vitro were divided into experimental group and control group.The control group and experimental group were pretreated with 5 concentration gradients of Salubrinal,and then the experimental group was irradiated with UVB,the control group without UVB irradiation,the survival of cells in each group was detected by MTT assay.4.Effect of UVB irradiation on endoplasmic reticulum stress in skin fibroblasts: cells were divided into 4 groups,each group was irradiated with UVB with different intensity,and then the endoplasmic reticulum stress-related proteins p-PERK,PERK,CHOP,p-IRE1α and cleaved caspase3 were detected by Western blot.5.Effects of Salubrinal on endoplasmic reticulum stress in skin fibroblasts irradiated by UVB: the experiment was divided into 4 groups: control group,Salubrinal treatment group,UVB irradiation group,Salubrinal pretreatmentbefore UVB irradiation group,and then the endoplasmic reticulum stress-related proteins p-PERK,PERK,CHOP and p-IRE1αwere detected by Western blot.6.The effect of Salubrinal on the intracellular Ca2+ level in skin fibroblasts exposed to UVB:cells were divided into two groups,Salubrinal treatment group and control group.Then cells were irradiated by three different intensity UVBs,and the corresponding Ca2+ signal was observed by confocal fluorescence microscope.Result: 1.After UVB irradiation on skin fibroblasts,the survival rate of the cells decreased.After pretreatment with different concentrations of Salubrinal,the cell survival rate increased in a dose-dependent manner.2.After UVB exposure to human skin fibroblasts,the expression levels of intracellular endoplasmic reticulum stress-related proteins p-PERK,CHOP,p-IRE1α,and cleaved caspase3 were increased in a dose-dependent manner.3.Compared with Salubrinal untreated group,the expression of p-PERK,CHOP and p-IRE1α of endoplasmic reticulum stress-responsive proteins decreased after UVB irradiation on human skin fibroblasts.4.Salubrinal prevents UVB exposure from increasing levels of Ca2+ in human skin fibroblasts.Conclusion: 1.UVB irradiation can cause skin fibroblasts to die and Salubrinal has a protective effect.2.UVB irradiation induces skin fibroblast death through endoplasmic reticulum stress and imbalance of calcium homeostasis.Salubrinal protects it by blocking endoplasmic reticulum stress and regulating calcium homeostasis.