Abstract: Objective To investigate the effect of ultraviolet B(UVB)irradiation on the expression of transferrin receptor(TfR),and the underlying mechanism for such an expression,in HaCaT cells. Methods Cultured HaCaT cells were irradiated with different doses ofUVB(0,10,20,30 mJ/cm²),followed by another 24-hour culture.The epidermal growth factor receptor inhibitor PD153035,PI3K inhibitor LY294002,and wortmannin,respectively,were used to treat the cultured HaCaT cells before the irradiation. The expression of TfR mRNA was assessed by real-time reverse transcription PCR at 0,2,4,8,16 h after UVB irradiation.The expression of TfR protein was detected by flow cytometry using anti-human TfR-FITC monoclonal antibody at 0,6,12,and 24 h after the irradiation.Results Within a dose range of 10-30 mJ/cm², ultraviolet B irradiation upregulated the mRNA and protein expressions of TfR in a dose-dependent manner. This upregulation was significantly inhibited by PD153035,LY294002,or wortmannin(all P<0.01).Conclusion These results suggest that ultraviolet B irradiation upregulates the expression of TfR via the EGFR/PI3K/AKT signaling pathway in HaCaT cells.

Key words: Ultraviolet rays, Receptor, epidermal growth factor, 1-Phosphatidylinositol 3-kinase, Receptors, transferrin