Resveratrol Protects HaCaT Cells From Ultraviolet B-induced Photoaging Via Upregulation Of HSP27 And Modulation Of Mitochondrial Caspase-dependent Apoptotic Pathway

Objectives: The skin is the outermost protective barrier between the internal and external environments in humans.Chronic exposure to ultraviolet(UV)radiation is a major cause of skin photoaging.Evidence suggests that resveratrol suppresses UVB-induced photoaging,whereas its mechanism is not clear.In this study,we aimed to investigate the protective effect of resveratrol against UVB-induced photoaging in HaCat cells and to determine the underlying mechanisms.Methods: Cell viability was measured by CCK-8.Apoptosis cells were analyzed by flow cytometry.The mRNA and protein expression levels were measured by quantitative real-time polymerase chain reaction(qRT-PCR)and western blot.Results: Resveratrol inhibited UVB-induced apoptosis by upregulating the expression of HSP27,reducing the production of proapoptotic proteins such as p65,Bax,and cleaved caspase-3,andpromoting the expression of anti-apoptotic protein Bcl-2.However,UVB irradiation on HaCaT cells pretreated with resveratrol led to the upregulation of Bax,downregulation of Bcl-2,and promotion of p65 and caspase-3 activation after silencing of HSP27 gene.These findings suggest that the inhibition of HSP27 expression can partially reverse the anti-apoptotic effect of resveratrol and confirm that resveratrol can regulate HSP27 and thuscontrol p65 and caspase-3 activation.Conclusions: Resveratrol plays a role in photoprotection by upregulating HSP27 expression,increasing Bcl-2/Bax ratio,and inhibiting caspase-3 activity and p65 expression.