title: Regulation of eNOS expression in brain endothelial cells by perinuclear EP(3) receptors.
abstract: We reported upregulation of endothelial nitric oxide synthase (eNOS) by PGE(2) in tissues and presence of perinuclear PGE(2) receptors (EP). We presently studied mechanisms by which PGE(2) induces eNOS expression in cerebral microvessel endothelial cells (ECs). 16,16-Dimethyl PGE(2) and selective EP(3) receptor agonist M&B28767 increased eNOS expression in ECs and the NO-dependent vasorelaxant responses induced by substance P on cerebral microvessels. These effects could be prevented by prostaglandin transporter blocker bromcresol green and actinomycin D. EP(3) immunoreactivity was confirmed on plasma and perinuclear membrane of ECs. M&B28767 increased eNOS RNA expression in EC nuclei, and this effect was augmented by overexpression of EP(3) receptors. M&B28767 also induced increased phosphorylation of Erk-1/2 and Akt, as well as changes in membrane potential revealed by the potentiometric fluorescent dye RH421, which were prevented by iberiotoxin; perinuclear K(Ca) channels were detected, and their functionality corroborated by NS1619-induced Ca(2+) signals and nuclear membrane potential changes. Moreover, pertussis toxin, Ca(2+) chelator, and channel blockers EGTA, BAPTA, and SK&F96365, as well as K(Ca) channel blocker iberiotoxin, protein-kinase inhibitors wortmannin and PD 98059, and NF-kappaB inhibitor pyrrolidine dithiocarbamate prevented M&B28767-induced increase in Ca(2+) transients and/or eNOS expression in EC nuclei. We describe for the first time that PGE(2) through its access into cell by prostaglandin transporters induces eNOS expression by activating perinuclear EP(3) receptors coupled to pertussis toxin-sensitive G proteins, a process that depends on nuclear envelope K(Ca) channels, protein kinases, and NF-kappaB; the roles for nuclear EP(3) receptors seem different from those on plasma membrane.
authors.affiliation: Departments of Pediatrics, Research Center of Hôpital Sainte-Justine, Montréal.
authors.forename: Fernand
authors.initials: F
authors.lastname: Gobeil
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dumont
authors.forename: Anne Marilise
authors.initials: AM
authors.lastname: Marrache
authors.forename: Alejandro
authors.initials: A
authors.lastname: Vazquez-Tello
authors.forename: Sylvie G
authors.initials: SG
authors.lastname: Bernier
authors.forename: Daniel
authors.initials: D
authors.lastname: Abran
authors.forename: Xin
authors.initials: X
authors.lastname: Hou
authors.forename: Martin H
authors.initials: MH
authors.lastname: Beauchamp
authors.forename: Christiane
authors.initials: C
authors.lastname: Quiniou
authors.forename: Asmaa
authors.initials: A
authors.lastname: Bouayad
authors.forename: Sanaa
authors.initials: S
authors.lastname: Choufani
authors.forename: Mousumi
authors.initials: M
authors.lastname: Bhattacharya
authors.forename: Stephane
authors.initials: S
authors.lastname: Molotchnikoff
authors.forename: Alfredo
authors.initials: A
authors.lastname: Ribeiro-Da-Silva
authors.forename: Daya R
authors.initials: DR
authors.lastname: Varma
authors.forename: Ghassan
authors.initials: G
authors.lastname: Bkaily
authors.forename: Sylvain
authors.initials: S
authors.lastname: Chemtob
mesh_terms: D000818:Animals; D001921:Brain / Q000098:blood supply*; D002478:Cells, Cultured; D015232:Dinoprostone / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000502:physiology*; D008833:Microcirculation / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000235:genetics; D052250:Nitric Oxide Synthase Type III; D018078:Receptors, Prostaglandin E / Q000502:physiology*; D013552:Swine; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D018078:Receptors, Prostaglandin E; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D015232:Dinoprostone