Research article summary (published 12 Oct 2009):

Bestrophin-1 encodes for the Ca2+-activated anion channel in hippocampal astrocytes.

Full Abstract

In mammalian brain, neurons and astrocytes are reported to express various chloride and anion channels, but the evidence for functional expression of Ca(2+)-activated anion channel (CAAC) and its molecular identity have been lacking. Here we report electrophysiological evidence for the CAAC expression and its molecular identity by mouse Bestrophin 1 (mBest1) in astrocytes of the mouse brain. Using Ca(2+) imaging and perforated-patch-clamp analysis, we demonstrate that astrocytes displayed an inward current at holding potential of -70 mV that was dependent on an increase in intracellular Ca(2+) after G(alphaq)-coupled receptor activation. This current was mediated mostly by anions and was sensitive to well known anion channel blockers such as niflumic acid, 5-nitro-2(3-phenylpropylamino)-benzoic acid, and flufenamic acid. To find the molecular identity of the anion channel responsible for the CAAC current, we analyzed the expression of candidate genes and found that the mRNA for mouse mBest1 is predominantly expressed in acutely dissociated or cultured astrocytes. Whole-cell patch-clamp analysis using HEK293T cells heterologously expressing full-length mBest1 showed a Ca(2+)-dependent current mediated by mBest1, with a complete impairment of the current by a putative pore mutation, W93C. Furthermore, mBest1-mediated CAAC from cultured astrocytes was significantly reduced by expression of mBest1-specific short hairpin RNA (shRNA), suggesting that the CAAC is mediated by a channel encoded by mBest1. Finally, hippocampal CA1 astrocytes in hippocampal slice also showed mBest1-mediated CAAC because it was inhibited by mBest1-specific shRNA. Collectively, these data provide molecular evidence that the mBest1 channel is responsible for CAAC function in astrocytes.

Author information

Author/s: Park, Hyungju (H); Oh, Soo-Jin (SJ); Han, Kyung-Seok (KS); Woo, Dong Ho (DH); Park, Hyekyung (H); Mannaioni, Guido (G); Traynelis, Stephen F (SF); Lee, C Justin (CJ);

Affiliation: Center for Neural Science, Convergence Technology Laboratory, Korea Institute of Science and Technology, Seoul 136-791, Korea.

Grants: NS39419 (Agency:NINDS NIH HHS) ; NS43875 (Agency:NINDS NIH HHS)

Journal and publication information

Publication Type: In Vitro; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't

Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience (J Neurosci), published in United States. (Language: eng)

Reference: 2009-Oct; vol 29 (issue 41) : pp 13063-73

Dates: Created 2009/10/15; Completed 2009/10/30;

PMID: 19828819, status: MEDLINE (last retrieval date: 10/30/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Adenosine Triphosphate - analogs & derivatives; pharmacology Analysis of Variance Animals Animals, Newborn Astrocytes - physiology Bradykinin - pharmacology Calcium - metabolism Cells, Cultured Cerebral Cortex - cytology Chelating Agents - pharmacology Chloride Channels - genetics; physiology Dinoprostone - pharmacology Egtazic Acid - analogs & derivatives; pharmacology Electric Stimulation - methods Enzyme Inhibitors - pharmacology Estrenes - pharmacology

Estrenes - pharmacology Eye Proteins - metabolism Gene Expression Regulation - genetics Hippocampus - cytology Humans Lysophospholipids - pharmacology Membrane Potentials - drug effects; genetics Mice Mice, Inbred C57BL Oligopeptides - pharmacology Patch-Clamp Techniques Pyrrolidinones - pharmacology RNA, Small Interfering - genetics Thapsigargin - pharmacology Thionucleotides - pharmacology Transfection - methods

Associated Chemicals: Chelating Agents (0) ; Chloride Channels (0) ; Enzyme Inhibitors (0) ; Estrenes (0) ; Eye Proteins (0) ; Lysophospholipids (0) ; Oligopeptides (0) ; PAR-1-activating peptide (0) ; Pyrrolidinones (0) ; RNA, Small Interfering (0) ; Thionucleotides (0) ; Vmd2 protein, mouse (0) ; 1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (112648-68-7) ; 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester (139890-68-9) ; lysophosphatidic acid (22002-87-5) ; Dinoprostone (363-24-6) ; 2-methylthio-ATP (43170-89-4) ; Adenosine Triphosphate (56-65-5) ; Bradykinin (58-82-2) ; Egtazic Acid (67-42-5) ; Thapsigargin (67526-95-8) ; Calcium (7440-70-2)

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