title: Functional expression of the CXC-chemokine receptor-4/fusin on mouse microglial cells and astrocytes.
abstract: The mRNA for the seven-transmembrane-spanning G protein-coupled receptor fusin/CXCR-4 is expressed in primary mouse astrocyte cultures and the transformed mouse microglial cell line, N9. Cell surface expression of fusin in these cells was confirmed by staining with a polyclonal anti-fusin Ab. The functional capacity of this chemokine receptor was examined by evaluating the calcium responses following stimulation of glial cells with the CXC-chemokine, stromal-derived cell factor-1alpha (SDF-1alpha). Both astrocytes and microglial cells mobilized calcium following stimulation with chemically synthesized SDF-1alpha. SDF-1alpha- and carbachol-mediated calcium responses of astrocytes were partially inhibited by treatment with pertussis toxin (PTx), suggesting receptor coupling to a combination of G alpha(i) and other G proteins. In contrast, the calcium responses of microglial cells to SDF-1alpha were completely PTx sensitive, while responses to carbachol stimulation were PTx resistant. The ability of SDF-1alpha to induce glial cell migration was also examined. Synthetic SDF-1alpha was a potent chemoattractant for mouse microglial cells at ligand concentrations of 10 to 500 ng/ml; peak responses were noted at 100 ng/ml. In contrast, astrocytes did not migrate toward a gradient of SDF-1alpha. The failure of SDF-1alpha to induce astrocyte migration was specific, as another chemokine, macrophage inflammatory protein-1alpha, triggered astrocyte chemotaxis.
authors.affiliation: Department of Pathology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: S
authors.initials: S
authors.lastname: Tanabe
authors.forename: M
authors.initials: M
authors.lastname: Heesen
authors.forename: I
authors.initials: I
authors.lastname: Yoshizawa
authors.forename: M A
authors.initials: MA
authors.lastname: Berman
authors.forename: Y
authors.initials: Y
authors.lastname: Luo
authors.forename: C C
authors.initials: CC
authors.lastname: Bleul
authors.forename: T A
authors.initials: TA
authors.lastname: Springer
authors.forename: K
authors.initials: K
authors.lastname: Okuda
authors.forename: N
authors.initials: N
authors.lastname: Gerard
authors.forename: M E
authors.initials: ME
authors.lastname: Dorf
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism* / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D002461:Cell Line, Transformed; D002465:Cell Movement / Q000187:drug effects; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D016207:Cytokines / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000096:biosynthesis*; D051379:Mice; D008807:Mice, Inbred BALB C; D017628:Microglia / Q000378:metabolism* / Q000473:pathology; D019718:Receptors, CXCR4; D015728:Receptors, HIV / Q000096:biosynthesis*
chemical_list: D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D016207:Cytokines; D008565:Membrane Proteins; D019718:Receptors, CXCR4; D015728:Receptors, HIV; D019204:GTP-Binding Proteins; D002118:Calcium