title: TRPV4 regulates the integrity of the blood-cerebrospinal fluid barrier and modulates transepithelial protein transport.
abstract: The diffusion of materials from systemic circulation to the central nervous system (CNS) is restricted by the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). Choroid plexus epithelial cells (CPECs) of the brain ventricles constitute the BCSFB and regulate the infiltration of plasma proteins as well as immune cells into the interstitium of the CNS. The barrier function is altered in pathologic conditions. However, the regulatory mechanism of BCSFB is not fully understood. Here, we investigated the function of transient receptor potential vanilloid 4 (TRPV4), a polymodally gated divalent cation channel that is highly expressed in CPECs. TRPV4 was localized broadly on the apical membrane in swine CPECs, in contrast with an intense ciliary localization found on other cell types. Treatment with the TRPV4-specific agonist, GSK1016790A (GSK; EC₅₀ 34 nM), induced a robust calcium influx and an immediate serine/threonine protein phosphorylation. The agonist treatment induced a marked decrease in the amount of filamentous actin and disintegrated the cell junctions in 10-20 minutes. In contrast, inhibition of the basal TRPV4 activity with the TRPV4-specific antagonist, HC067047 (HC; IC₅₀ 74 nM), reduced the basolateral-to-apical transport of α-2-macroglobulin (A2M). Overall, this study demonstrated a novel physiologic function of TRPV4 in the regulation of BCSFB permeability.
authors: *Department of Anatomy and Cell Biology and Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Chuo, Yamanashi, Japan; and Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku, Tokyo, Japan.
authors: Keishi
authors: K
authors: Narita
authors: *Department of Anatomy and Cell Biology and Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Chuo, Yamanashi, Japan; and Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku, Tokyo, Japan.
authors: Shohei
authors: S
authors: Sasamoto
authors: *Department of Anatomy and Cell Biology and Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Chuo, Yamanashi, Japan; and Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku, Tokyo, Japan.
authors: Schuichi
authors: S
authors: Koizumi
authors: *Department of Anatomy and Cell Biology and Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Chuo, Yamanashi, Japan; and Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku, Tokyo, Japan.
authors: Shizuka
authors: S
authors: Okazaki
authors: *Department of Anatomy and Cell Biology and Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Chuo, Yamanashi, Japan; and Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku, Tokyo, Japan.
authors: Hideki
authors: H
authors: Nakamura
authors: *Department of Anatomy and Cell Biology and Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Chuo, Yamanashi, Japan; and Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku, Tokyo, Japan.
authors: Takafumi
authors: T
authors: Inoue
authors: *Department of Anatomy and Cell Biology and Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Chuo, Yamanashi, Japan; and Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku, Tokyo, Japan stakeda@yamanashi.ac.jp.
authors: Sen
authors: S
authors: Takeda
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism*; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D002555:Cerebrospinal Fluid / Q000378:metabolism*; D002831:Choroid Plexus / Q000166:cytology; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D018613:Microscopy, Confocal; D010766:Phosphorylation / Q000187:drug effects; D061251:Primary Cell Culture; D021381:Protein Transport / Q000187:drug effects; D012694:Serine / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D013552:Swine; D050916:TRPV Cation Channels / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013912:Threonine / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000378:metabolism
chemical_list: C530602:N-(1-((4-(2-(((2,4-dichlorophenyl)sulfonyl)amino)-3-hydroxypropanoyl)-1-piperazinyl)carbonyl)-3-methylbutyl)-1-benzothiophene-2-carboxamide; D013449:Sulfonamides; D050916:TRPV Cation Channels; D000511:alpha-Macroglobulins; D013912:Threonine; D012694:Serine; D007930:Leucine; D002118:Calcium
keywords: actin; calcium imaging; subcellular localization