title: Ultraviolet A irradiation inhibits thymus and activation-regulated chemokine (TARC/CCL17) production by a human keratinocyte HaCaT cell line.
abstract: Ultraviolet A (UVA) irradiation modulates the immunological functions of skin. We examined the effect of UVA irradiation on the basal and the IFN-gamma-and TNF-alpha-stimulation-induced production of thymus-and activation-regulated chemokine (TARC/CCL17) using HaCaT cells. UVA irradiation inhibited the basal levels of both TARC mRNA expression and TARC protein production. UVA irradiation also significantly inhibited TARC mRNA expression and TARC protein secretion that were induced by co-stimulation with IFN-y and TNF-alpha. A time course study showed that: the significant suppression of TARC mRNA expression was detected 8 hours after irradiation and continued for 36 hours; the strongest inhibition of TARC protein secretion occurred in the first 8 hours after UVA irradiation and continued for 36 hours. Our data provide the first evidence that UVA inhibits TARC mRNA expression and TARC protein production by keratinocytes in a dose-dependent manner. These results may suggest an explanation for the UV-induced therapeutic effect.
authors.affiliation: Department of Dermatology, Fukushima Medical University School of Medicine, Hikarigaoka 1, Fukushima 960-1295, Japan.
authors.forename: Xueyi
authors.initials: X
authors.lastname: Zheng
authors.forename: Koichiro
authors.initials: K
authors.lastname: Nakamura
authors.forename: Michiko
authors.initials: M
authors.lastname: Tojo
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Akiba
authors.forename: Noritaka
authors.initials: N
authors.lastname: Oyama
authors.forename: Akiko
authors.initials: A
authors.lastname: Nishibu
authors.forename: Fumio
authors.initials: F
authors.lastname: Kaneko
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Tsunemi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kakinuma
authors.forename: Hidehisa
authors.initials: H
authors.lastname: Saeki
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Tamaki
mesh_terms: D002460:Cell Line / Q000528:radiation effects; D054414:Chemokine CCL17; D019742:Chemokines, CC / Q000096:biosynthesis* / Q000235:genetics; D004307:Dose-Response Relationship, Radiation; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D015603:Keratinocytes / Q000166:cytology / Q000528:radiation effects*; D012333:RNA, Messenger / Q000528:radiation effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: C106230:CCL17 protein, human; D054414:Chemokine CCL17; D019742:Chemokines, CC; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma