Effects of ultraviolet on mitochondrial functions and apoptosis in HaCaT cells / 中国病理生理杂志

ABSTRACT

AIM: To study the effects of ultraviolet (UV) on mitochondrial functions and apoptosis in HaCaT cells.METHODS: After irradiation by UV at low dose(UVA 2 J/cm~2,UVB 10 mJ/cm~2) and high dose(UVA 6 J/cm~2,UVB(30 mJ/cm~2),) HaCaT cells were cultured for 15 hours.Flow cytometry was used to measure mitochondrial membrane potential,mitochondrial mass and apoptotic rate.Annexin V-FITC/PI staining of apoptotic cells was analyzed by laser confocal microscopy.RESULTS: After UV irradiation,cell proportion with low mitochondrial membrane potential increased with irradiation doses.The proportion of control group,low dose group and high dose group were 7.94%?1.02%,25.87%?4.55% and 39.27%?5.32%,respectively.Cells proportion with low mitochondrial mass increased with irradiation doses.The proportion of control group,low dose group and high dose group were 15.19%?1.58%,40.36%?4.41% and 68.79%?5.46%,respectively.The hypodiploid peaks of DNA content analysis represented the apoptotic rate of HaCaT cells.The apoptotic rate of control group,low dose group and high dose group were 1.82%?0.51%,30.16%?5.47% and 58.49%?5.98%,respectively.To analyze the cells apoptosis by staining with annexin V-FITC and PI,the results were consistent with those of DNA content analysis.Cells in control group showed almost no positive staining cells.Single annexin V-FITC positive cells in low dose group and double positive cells in high dose group were predominant,respectively.CONCLUSION: UV irradiation induces HaCaT cell mitochondrial depolarization,as well as mitochondrial mass loss.These changes are related to cell apoptosis.