title: Blood-brain barrier damage induces release of alpha2-macroglobulin.
abstract: Blood-brain barrier (BBB) failure occurs in many neurological diseases and is caused in part by activation of proinflammatory factors including matrix metalloproteinases. Counterbalancing, "BBB protective" cascades have recently been described, including NO-mediated interleukin 6 release by glia. Interleukin 6 has been shown to trigger production of matrix metalloproteinase inhibitors such as alpha2-macroglobulin (alpha2M). We hypothesized that BBB failure may result in increased alpha(2)M release by perivascular astrocytes. This was initially tested in patients undergoing iatrogenic BBB disruption by hyperosmotic mannitol for intra-arterial chemotherapy of brain tumors. Serum samples revealed significantly increased levels of alpha2M at 4 h after BBB disruption by hyperosmotic mannitol. In parallel in vitro experiments, we observed a similar increase of alpha2M release by astrocytes under conditions mimicking BBB failure and perivascular edema. For both experiments, protein analysis was initially performed by bidimensional gel electrophoresis and mass spectrometry followed by Western blotting immunodetection. We conclude that, in addition to proinflammatory changes, BBB failure may also trigger protective release of alpha2M by perivascular astrocytes as well as peripheral source.
authors.affiliation: Department of Neurological Surgery, Cerebrovascular Research Center, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
authors.forename: Luca
authors.initials: L
authors.lastname: Cucullo
authors.forename: Nicola
authors.initials: N
authors.lastname: Marchi
authors.forename: Matteo
authors.initials: M
authors.lastname: Marroni
authors.forename: Vincent
authors.initials: V
authors.lastname: Fazio
authors.forename: Shobu
authors.initials: S
authors.lastname: Namura
authors.forename: Damir
authors.initials: D
authors.lastname: Janigro
mesh_terms: D001253:Astrocytes / Q000378:metabolism*; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism*; D001932:Brain Neoplasms / Q000188:drug therapy; D002478:Cells, Cultured; D002853:Chromatography, Liquid; D018920:Coculture Techniques; D015180:Electrophoresis, Gel, Two-Dimensional; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D007269:Injections, Intra-Arterial; D008353:Mannitol / Q000008:administration & dosage / Q000009:adverse effects; D013058:Mass Spectrometry; D009995:Osmosis; D010539:Permeability; D000511:alpha-Macroglobulins / Q000378:metabolism*
chemical_list: D000511:alpha-Macroglobulins; D008353:Mannitol