RESUMEN
BACKGROUND: Transforming growth factor-beta (TGF-beta), a multifunctional growth factor, has three isoforms: TGF-beta1, TGF-beta2, and TGF-beta3. Different isoforms of TGF-beta are associated with different proliferation and differentiation states of the epidermis. Narrow band ultraviolet B (NBUVB) emits a concentrated UVB source of 311 nm. NBUVB 1,000 mJ/cm2 induces apoptosis in approximately 50% of keratinocytes. OBJECTIVE: The purpose of this study was to evaluate whether irradiation with NBUVB would alter the expression and production of TGF-beta1, 2, and 3. METHODS: We measured TGF-beta1, 2, and 3 mRNA and TGF-beta1 and 2 protein levels at 800, 1,000, and 1,200 mJ/cm2 for 24 hours and 48 hours. RESULTS: TGF-beta1 mRNA levels were increased at both 24 hr and 48 hr, TGF-beta2 mRNA levels were decreased at both 24 hr and 48 hr, and TGF-beta3 mRNA levels were increased at 24 hr and similar to control at 48 hr. TGF-beta1 protein levels were increased at 48 hr but decreased at 24 hr. TGF-beta2 protein levels were decreased at both 24 hr and 48 hr. CONCLUSION: The results suggest a possible role for TGF-beta1 after NBUVB irradiation and opposing roles for TGF-beta1 and TGF-beta2 isoforms in NBUVB irradiation.