title: Synthesis and secretion of insulin-like growth factor (IGF)-II and IGF binding protein-2 by cultivated brain meningeal cells.
abstract: The meninges (the pia mater and the arachnoid) covering the surface of brain parenchyma are known to participate in the regulation of blood circulation and the blood-cerebrospinal fluid barrier. In the present study, we isolated and characterized some of the major proteins secreted into the conditioned medium of the meningeal cell cultures prepared from 1-2-day-old rats. Five protein molecules (7 kDa, 16 kDa, 18 kDa, 27 kDa and 32 kDa) were recognized as major proteins in the conditioned medium by SDS-PAGE. The major proteins were isolated and purified to homogeneity, respectively. Their N-terminal sequences, except that of 27 kDa protein, were successfully determined. Homology search has revealed that the N-terminal sequences of the 7 kDa protein and the 32 kDa protein were identical with those of insulin-like growth factor-II (IGF-II) and IGF-binding protein-2 (IGFBP-2), respectively. The N-terminal sequences of the 16 kDa and 18 kDa molecules were identical with those of the corresponding fragments of IGFBP-2. The present study demonstrates that cultured meningeal cells produce and secrete large amounts of IGF-II and IGFBP-2. The meninges may, therefore, be one of the main sources of these proteins in the cerebrospinal fluid and involved in the modulation of neuronal and/or glial cell survival or functioning.
authors.affiliation: Department of Molecular Physiology, Gunma University, Maebashi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Ohe
authors.forename: K
authors.initials: K
authors.lastname: Tatemoto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000166:cytology; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D008578:Meninges / Q000166:cytology / Q000378:metabolism*; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D051381:Rats
chemical_list: D017077:Culture Media, Conditioned; D018971:Insulin-Like Growth Factor Binding Protein 2; D007335:Insulin-Like Growth Factor II