title: Microglia activation influences dye coupling and Cx43 expression of the astrocytic network.
abstract: Under inflammatory conditions, activated microglia are capable of producing proinflammatory cytokines that are reported to influence cell-to-cell communication. The present study was performed to evaluate the influence of microglial activation on the coupling efficiency of the astroglial network. Primary astrocyte cultures of newborn rats were cocultured with either 5% (M5) or 30% (M30) microglia. Microglial activation (rounded phagocytotic phenotype) was investigated using the monoclonal anti-ED1 antibody, and immunofluorescence with a polyclonal anti-Cx43 antibody was used to study astroglial Cx43 expression and distribution. Functional coupling of astrocytes was evaluated by monitoring the transfer of microinjected Lucifer yellow into neighboring cells. The data obtained can be summarized as follows: astroglia/M30 cocultures contained significantly fewer resting microglia and significantly more activated microglia than the M5 cocultures; significantly reduced astroglial Cx43 staining was found in M30 cocultures concurrently with a reduced number of dye coupled astrocytes; and the positive correlation of percent activated microglia with reduced astroglial Cx43 expression was highly significant, indicating that the degree of intercellular communication in the astroglial network may be modulated by the activation of microglia under in vitro conditions.
authors.affiliation: Department of Neuroanatomy and Molecular Brain Research, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Faustmann
authors.forename: Claus G
authors.initials: CG
authors.lastname: Haase
authors.forename: Sabine
authors.initials: S
authors.lastname: Romberg
authors.forename: Daniel
authors.initials: D
authors.lastname: Hinkerohe
authors.forename: Dominika
authors.initials: D
authors.lastname: Szlachta
authors.forename: Dirk
authors.initials: D
authors.lastname: Smikalla
authors.forename: Dorothee
authors.initials: D
authors.lastname: Krause
authors.forename: Rolf
authors.initials: R
authors.lastname: Dermietzel
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000276:immunology / Q000378:metabolism*; D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D048429:Cell Size / Q000502:physiology; D002478:Cells, Cultured; D002633:Chemotaxis / Q000502:physiology; D018920:Coculture Techniques; D018031:Connexin 43 / Q000378:metabolism*; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D053331:Ectodysplasins; D004660:Encephalitis / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D017629:Gap Junctions / Q000276:immunology / Q000378:metabolism*; D005911:Gliosis / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D007150:Immunohistochemistry; D007546:Isoquinolines; D008565:Membrane Proteins / Q000378:metabolism; D017628:Microglia / Q000378:metabolism*; D010641:Phenotype; D051381:Rats; D015398:Signal Transduction / Q000502:physiology
chemical_list: D018031:Connexin 43; D016207:Cytokines; D053331:Ectodysplasins; D007546:Isoquinolines; D008565:Membrane Proteins; C017475:lucifer yellow