title: The leukotriene B4 receptor BLT2 protects barrier function via actin polymerization with phosphorylation of myosin phosphatase target subunit 1 in human keratinocytes.
abstract: Leukotriene B4 (LTB4 ) receptor type 2 (BLT2) is a novel G-protein-coupled receptor, which selectively binds to 12(S)-hydroxyheptadeca-5Z,8E,10E-trienoic acid (12-HHT) with stronger affinity than to LTB4 . Recently, 12-HHT has been shown to have a protective effect on the epidermal barrier in human keratinocytes or transfectant cells overexpressing BLT2. Because the protective activity of BLT2 in high-calcium conditions, which occurs in well-differentiated cells, is exerted through increasing the integrity of tight junctions, we investigated the effects of 12-HHT on the barrier function of human keratinocytes in low-calcium conditions that mimic the basal layer; to our knowledge, this has not been reported previously. After stimulation with or without 12-HHT, barrier function was measured using transepithelial electrical resistance (TER) and dextran permeability assay. Expression levels of adhesion molecules and actin polymerization were also evaluated. Treatment with 12-HHT increased TER, along with decreased epidermal permeability of dextran in human keratinocytes. Furthermore, 12-HHT induced actin polymerization with phosphorylation of myosin phosphatase target subunit 1. These results suggest that the ligation of BLT2 protects permeability barrier function by enhancing cell-cell contact, even under low-calcium conditions, and indicate that a BLT2 agonist could be a novel therapeutic target for barrier-disrupted skin diseases.
authors.affiliation: Department of Dermatology, Kyushu University School of Medicine, Fukuoka, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Chiba
authors.affiliation: Department of Dermatology, Kyushu University School of Medicine, Fukuoka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakahara
authors.affiliation: Department of Dermatology, Kyushu University School of Medicine, Fukuoka, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Hashimoto-Hachiya
authors.affiliation: Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Yokomizo
authors.affiliation: Department of Dermatology, Kyushu University School of Medicine, Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uchi
authors.affiliation: Department of Dermatology, Kyushu University School of Medicine, Fukuoka, Japan.
authors.forename: Masutaka
authors.initials: M
authors.lastname: Furue
mesh_terms: D000199:Actins / Q000378:metabolism*; D002460:Cell Line; D003911:Dextrans; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D043263:Myosin-Light-Chain Phosphatase / Q000378:metabolism*; D010766:Phosphorylation; D058105:Polymerization; D018102:Receptors, Leukotriene B4 / Q000819:agonists / Q000378:metabolism*
chemical_list: D000199:Actins; D003911:Dextrans; D005231:Fatty Acids, Unsaturated; C485878:LTB4R2 protein, human; D018102:Receptors, Leukotriene B4; C015219:fluorescein isothiocyanate dextran; C008033:12-hydroxy-5,8,10-heptadecatrienoic acid; D043263:Myosin-Light-Chain Phosphatase; C490372:PPP1R12A protein, human; D016650:Fluorescein-5-isothiocyanate
keywords: 12-HHT; BLT1; Epidermis; cell adhesion; transepithelial electrical resistance