ABSTRACT
BACKGROUND: Phototherapy with narrow-band ultraviolet B (narrow-band UVB) is clinically effective treatment for atopic dermatitis. In the present study, we examined the effects of intranasal irradiation with narrow-band UVB on nasal symptom, upregulation of histamine H1 receptor (H1R) gene expression and induction of DNA damage in the nasal mucosa of allergic rhinitis (AR) model rat. METHODS: AR model rats were intranasally irradiated with 310 nm of narrow-band UVB. Nasal mucosal levels of H1R mRNA were measured using real-time quantitative reverse transcriptase (RT)-PCR. DNA damage was evaluated using cyclobutane pyrimidine dimer (CPD) immunostaining. RESULTS: In toluene 2,4-diisocyanate (TDI)-sensitized rats, TDI provoked sneezes and H1R gene expression in the nasal mucosa. Intranasal pre-irradiation with 310 nm narrow-band UVB at doses of 600 and 1400, but not 200 mJ/cm2 significantly inhibited the number of sneezes and upregulation of H1R gene expression provoked by TDI. CPD-positive cells appeared in the nasal mucosa after intranasal narrow-band UVB irradiation at a dose of 1400, but not 200 and 600 mJ/cm2. The suppression of TDI-provoked sneezes and upregulation of H1R gene expression lasted 24 hours, but not 48 hours, after narrow-band UVB irradiation with a dose of 600 mJ/cm2. CONCLUSIONS: Intranasal pre-irradiation with narrow-band UVB dose-dependently inhibited sneezes and upregulation of H1R gene expression of the nasal mucosa in AR model rats, suggesting that the inhibition of nasal upregulation of H1R gene expression suppressed nasal symptom. The suppression after narrow-band UVB irradiation at a dose of 600 mJ/cm2 was reversible without induction of DNA damage. These findings indicated that low-dose narrow-band UVB phototherapy could be effectively and safely used for AR treatment in a clinical setting. LEVEL OF EVIDENCE: NA.
ABSTRACT
Narrowband-ultraviolet B (NB-UVB) phototherapy is used for the treatment of atopic dermatitis. Previously, we reported that irradiation with 200 mJ/cm2 of 310 nm NB-UVB suppressed phorbol-12-myristate-13-acetate (PMA)-induced up-regulation of histamine H1 receptor (H1R) gene expression without induction of apoptosis in HeLa cells. However, the effect of NB-UVB irradiation on nasal symptoms is still unclear. Here, we show that low dose irradiation with 310 nm NB-UVB alleviates nasal symptoms in toluene 2,4-diisocyanate (TDI)-sensitized allergy model rats. Irradiation with 310 nm NB-UVB suppressed PMA-induced H1R mRNA up-regulation in HeLa cells dose-dependently at doses of 75-200 mJ/cm2 and reversibly at a dose of 150 mJ/cm2 without induction of apoptosis. While, at doses of more than 200 mJ/cm2, irradiation with 310 nm NB-UVB induced apoptosis. Western blot analysis showed that the suppressive effect of NB-UVB irradiation on H1R gene expression was through the inhibition of ERK phosphorylation. In TDI-sensitized rat, intranasal irradiation with 310 nm NB-UVB at an estimated dose of 100 mJ/cm2 once a day for three days suppressed TDI-induced sneezes and up-regulation of H1R mRNA in nasal mucosa without induction of apoptosis. These findings suggest that repeated intranasal irradiation with low dose of NB-UVB could be clinically used as phototherapy of AR.
