Abstract: Objective To investigate the effects of ultraviolet rays on the expression of haptoglobin mRNA in a human keratinocyte cell line, HaCaT cells. Methods RT-PCR was used to detect the expression of haptoglobin mRNA in UVA/UVB irradiated HaCaT cells at a time course. Results ①Following a dose of 12 J/cm² of UVA irradiation, the level of haptoglobin mRNA was significantly increased as compared with that of unirradiated control. The expression of haptolobin mRNA started to increase at 20 minutes after irradiation and reached the first peak at 6 h and the second peak at 48 h after irradiation. Significant statistical difference (P<0.05) in haptoglobin mRNA expression was observed between the unirradiated control and the irradiated groups (2 h, 4 h, 6 h, 24 h, 48 h after irradiation). ②Following 30 mJ/cm² of UVB irradiation, the expression of haptoglobin mRNA was significantly increased and came to the first peak at 4 h and the second peak at 48 h after irradiation. Significant statistical difference (P<0.05) in haptoglobin mRNA expression was observed between the unirradiated control and the irradiated groups (20 min, 2 h, 4 h, 6 h, 12 h, 48 h and 72 h after irradiation). Conclusions UVA and UVB are effective factors to upregulate the expression of haptoglobin mRNA in HaCaT cells, and the expression of haptoglobin mRNA varies with the progression of the time course after irradiation.

Key words: HaCaT cell, Globins, Ultraviolet rays