title: Phosphorylation of vasodilator-stimulated phosphoprotein: a consequence of nitric oxide- and cGMP-mediated signal transduction in brain capillary endothelial cells and astrocytes.
abstract: There is contradictory information on the relevance of nitric oxide (NO) and cGMP for the function of brain capillary endothelial cells (BCEC) forming the blood-brain barrier (BBB). Therefore, NO/cGMP-mediated signal transduction was investigated in cell cultures of BCEC and of astrocytes (AC) inducing BBB properties in BCEC. Constitutive, Ca2+-activated isoforms of NO synthase (NOS) were found in BCEC (endothelial NOS: eNOS) and in AC (neuronal NOS: nNOS), leading to increased NO release after incubation with the Ca2+-ionophore A23187. Both cell types expressed inducible NOS (iNOS) after incubation with cytokines. Soluble guanylate cyclase (sGC) was detected in both cell types. NO-dependent cGMP formation were observed in BCEC and, less pronounced, in AC. Furthermore, both cell types formed cGMP independently of NO via stimulation of particulate guanylate cyclase (pGC). cGMP-dependent protein kinase (PKG) type Ibeta, but not type II, was expressed in BCEC and AC. In BCEC, vasodilator-stimulated phosphoprotein (VASP) was detected, an established substrate of PKG and associated with microfilaments and cell-cell contacts. Phosphorylation of VASP was intensified by increased intracellular cGMP concentrations. The results indicate that BCEC and, to a smaller degree, AC can form NO and cGMP in response to different stimuli. In BCEC, NO/cGMP-dependent phosphorylation of VASP is demonstrated, thus providing a possibility of influencing cell-cell contacts.
authors.affiliation: Forschungsinstitut für Molekulare Pharmakologie, Alfred-Kowalke Str. 4, 10315, Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Sporbert
authors.forename: K
authors.initials: K
authors.lastname: Mertsch
authors.forename: A
authors.initials: A
authors.lastname: Smolenski
authors.forename: R F
authors.initials: RF
authors.lastname: Haseloff
authors.forename: G
authors.initials: G
authors.lastname: Schönfelder
authors.forename: M
authors.initials: M
authors.lastname: Paul
authors.forename: P
authors.initials: P
authors.lastname: Ruth
authors.forename: U
authors.initials: U
authors.lastname: Walter
authors.forename: I E
authors.initials: IE
authors.lastname: Blasig
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000737:chemistry / Q000166:cytology / Q000201:enzymology; D001798:Blood Proteins / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000502:physiology*; D002196:Capillaries / Q000737:chemistry / Q000166:cytology / Q000201:enzymology; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000378:metabolism*; D002450:Cell Communication / Q000502:physiology; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000032:analysis / Q000378:metabolism*; D062965:Cyclic GMP-Dependent Protein Kinase Type I; D017869:Cyclic GMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000737:chemistry / Q000166:cytology / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism; D008840:Microfilament Proteins; D009566:Nitrates / Q000032:analysis; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D009573:Nitrites / Q000032:analysis; D010750:Phosphoproteins / Q000032:analysis / Q000378:metabolism*; D010766:Phosphorylation; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D001798:Blood Proteins; D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D009566:Nitrates; D009573:Nitrites; D010750:Phosphoproteins; D012333:RNA, Messenger; D000098662:Vasodilator-Stimulated Phosphoprotein; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D062965:Cyclic GMP-Dependent Protein Kinase Type I; D017869:Cyclic GMP-Dependent Protein Kinases; D006162:Guanylate Cyclase; D006152:Cyclic GMP