Protection Of Tempol Against UVB Irradiation-Induced Damage On Hacat Cells

Objective:To study the protective effects of Tempol against UVB irradiation-induced damage on cultured HaCaT cells.Methods:HaCaT cells were irradiated with UVB for 4 second followed by 24 hours of incubation with fresh medium.Cell proliferation ability was studied with MTT asssy and early apoptosis was analyzed by flow cytometric method.Gene expressions of FoxO3a and BubR1 were detected by RT-PCR.HaCaT cells were cultured with different concentrations of Tempol(0.5,1,2,4,8mM). After 12 hours of incubation with Tempol,cell proliferation ability,early apoptosis,Gene expressions of FoxO3a and BubR1 were detected again.Results:After UVB irradiation,HaCaT cell proliferation ability was significantly suppressed and the apoptoic rate was significantly enhanced compared with the control group(P＜0.05).At the same time,the expression of FoxO3a mRNA was significantly increased and BubR1 mRNA was significantly decreased in the UVB irradiation group compared with the control group(P＜0.05). Pre-culturing with different concentrations of Tempol could significantly increase the proliferation ability and decrease the apoptotic rate of UVB-irradiated HaCaT cells(P＜0.05).Furthermore, Tempol could significantly down-regulate the mRNA expression of FoxO3a and significantly up-regulate the expression of BubR1 mRNA of UVB-irradiated HaCaT cells(P＜0.05).The protective effects of Tempol were gradually decreased along the increase of Tempol concentration applied.Conclusion:Tempol could protect HaCaT cells against UVB irradiation-induced cell damage.