title: Na-K-ATPase regulates intercellular communication in the vascular wall via cSrc kinase-dependent connexin43 phosphorylation.
abstract: Communication between vascular smooth muscle cells (VSMCs) is dependent on gap junctions and is regulated by the Na-K-ATPase. The Na-K-ATPase is therefore important for synchronized VSMC oscillatory activity, i.e., vasomotion. The signaling between the Na-K-ATPase and gap junctions is unknown. We tested here the hypothesis that this signaling involves cSrc kinase. Intercellular communication was assessed by membrane capacitance measurements of electrically coupled VSMCs. Vasomotion in isometric myograph, input resistance, and synchronized [Ca2+]itransients were used as readout for intercellular coupling in rat mesenteric small arteries in vitro. Phosphorylation of cSrc kinase and connexin43 (Cx43) were semiquantified by Western blotting. Micromole concentration of ouabain reduced the amplitude of norepinephrine-induced vasomotion and desynchronized Ca2+transients in VSMC in the arterial wall. Ouabain also increased input resistance in the arterial wall. These effects of ouabain were antagonized by inhibition of tyrosine phosphorylation with genistein, PP2, and by an inhibitor of the Na-K-ATPase-dependent cSrc activation, pNaKtide. Moreover, inhibition of cSrc phosphorylation increased vasomotion amplitude and decreased the resistance between cells in the vascular wall. Ouabain inhibited the electrical coupling between A7r5 cells, but pNaKtide restored the electrical coupling. Ouabain increased cSrc autophosphorylation of tyrosine 418 (Y418) required for full catalytic activity whereas pNaKtide antagonized it. This cSrc activation was associated with Cx43 phosphorylation of tyrosine 265 (Y265). Our findings demonstrate that Na-K-ATPase regulates intercellular communication in the vascular wall via cSrc-dependent Cx43 tyrosine phosphorylation.
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: Lise
authors.initials: L
authors.lastname: Hangaard
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Bouzinova
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Staehr
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: Vibeke S
authors.initials: VS
authors.lastname: Dam
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: Sukhan
authors.initials: S
authors.lastname: Kim
authors.affiliation: Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, West Virginia.
authors.forename: Zijian
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.|Department of Biomedicine, University of Copenhagen, Copenhagen, Denmark; and.
authors.forename: Christian
authors.initials: C
authors.lastname: Aalkjaer
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark; vvm@biomed.au.dk.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Matchkov
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000502:physiology; D020013:Calcium Signaling / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D018031:Connexin 43 / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D008638:Mesenteric Arteries / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000502:physiology; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000502:physiology; D010766:Phosphorylation; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: D018031:Connexin 43; C580592:Gja1 protein, rat; D019061:src-Family Kinases; D000254:Sodium-Potassium-Exchanging ATPase
keywords: Na-K-ATPase; artery; cSrc kinase signaling; gap junctions; vasomotion