Figure 4.

Effect of UVB irradiation on sebaceous lipogenesis and DGAT activity in DHS. DHS at the third passage were irradiated with UVB (0.62 kJ/m²) in serum-free conditions and then maintained for 24 h. (A) Harvested culture media and (B) cells were subjected to TLC analysis. (C) DHS at the third passage were irradiated with UVB at 0.12, 0.37 and 0.62 kJ/m². After the irradiation, the cells were maintained for 6 or 24 h, then DGAT activity was measured in the harvested cells. Data are presented as the mean ± standard deviation of three dishes. *P<0.05, **P<0.01 and ***P<0.01 vs. untreated controls. DHS, differentiated hamster sebocytes; TLC, thin-layer chromatography; DGAT, diglyceride acyltransferase; UVB, ultraviolet B; TG, triacylglycerol; FFAs, free fatty acids; Ch, cholesterol.