Inhibition of Akt phosphorylation by thrombin, histamine and lysophosphatidylcholine in endothelial cells. Differential role of protein kinase C

2.50
Hdl Handle:
http://hdl.handle.net/2336/15742
Title:
Inhibition of Akt phosphorylation by thrombin, histamine and lysophosphatidylcholine in endothelial cells. Differential role of protein kinase C
Authors:
Thors, Brynhildur; Halldorsson, Haraldur; Clarke, Gudrun D; Thorgeirsson, Gudmundur
Citation:
Atherosclerosis. 2003, 168(2):245-53
Issue Date:
1-Jun-2003
Abstract:
The protein kinase Akt is involved in embryonic vascular development and neoangiogenesis as well as in several endothelial cell functions, including activation of endothelial NO-synthase (eNOS) and promotion of endothelial cell survival. We have examined the effects of G-protein activators thrombin and histamine as well as lysophosphatidylcholine (LPC) on Akt phosphorylation in cultured human umbilical vein endothelial cells (HUVEC). Akt phosphorylation was analyzed with the phosphospecific Akt (Ser473) antibody by Western blotting. While epidermal growth factor (EGF) was a potent stimulator of Akt phosphorylation histamine, thrombin and LPC blocked its activation when used in cotreatment with EGF. Following inhibition or downregulation of protein kinase C (PKC), the inhibitory effect of both histamine and thrombin on the endothelial response to EGF was prevented. Furthermore, stimulation of PKC, using short-term 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment, markedly inhibited the stimulatory effects of EGF on Akt phosphorylation. Rottlerin, an inhibitor of the PKCdelta, but not Gö6976, which is an inhibitor of alpha, beta, gamma and isoforms, reversed the inhibitory effects of histamine. Conversely, inhibition or downregulation of PKC did not prevent the inhibitory effect of LPC. Akt phosphorylation was also increased by sphingosine 1-phosphate (S1P) treatment and this activity was influenced by the various cotreatments in the same way as the activation by EGF. Overall, this study demonstrated that the G-protein activators thrombin and histamine inhibited both EGF- and S1P-mediated Akt phosphorylation in HUVEC by activation of PKCdelta, while the inhibitory effects of LPC were independent of PKCdelta.
Description:
To access publisher full text version of this article. Please click on the hyperlink in Additional Links field
Additional Links:
http://www.sciencedirect.com/science/article/B6T12-48JK65S-2/2/6a3cfbb8c99d7ed73cd4a1ce150835cb

Full metadata record

DC FieldValue Language
dc.contributor.authorThors, Brynhildur-
dc.contributor.authorHalldorsson, Haraldur-
dc.contributor.authorClarke, Gudrun D-
dc.contributor.authorThorgeirsson, Gudmundur-
dc.date.accessioned2008-01-07T13:42:27Z-
dc.date.available2008-01-07T13:42:27Z-
dc.date.issued2003-06-01-
dc.identifier.citationAtherosclerosis. 2003, 168(2):245-53en
dc.identifier.issn0021-9150-
dc.identifier.pmid12801607-
dc.identifier.doi10.1016/S0021-9150(03)00127-8-
dc.identifier.urihttp://hdl.handle.net/2336/15742-
dc.descriptionTo access publisher full text version of this article. Please click on the hyperlink in Additional Links fielden
dc.description.abstractThe protein kinase Akt is involved in embryonic vascular development and neoangiogenesis as well as in several endothelial cell functions, including activation of endothelial NO-synthase (eNOS) and promotion of endothelial cell survival. We have examined the effects of G-protein activators thrombin and histamine as well as lysophosphatidylcholine (LPC) on Akt phosphorylation in cultured human umbilical vein endothelial cells (HUVEC). Akt phosphorylation was analyzed with the phosphospecific Akt (Ser473) antibody by Western blotting. While epidermal growth factor (EGF) was a potent stimulator of Akt phosphorylation histamine, thrombin and LPC blocked its activation when used in cotreatment with EGF. Following inhibition or downregulation of protein kinase C (PKC), the inhibitory effect of both histamine and thrombin on the endothelial response to EGF was prevented. Furthermore, stimulation of PKC, using short-term 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment, markedly inhibited the stimulatory effects of EGF on Akt phosphorylation. Rottlerin, an inhibitor of the PKCdelta, but not Gö6976, which is an inhibitor of alpha, beta, gamma and isoforms, reversed the inhibitory effects of histamine. Conversely, inhibition or downregulation of PKC did not prevent the inhibitory effect of LPC. Akt phosphorylation was also increased by sphingosine 1-phosphate (S1P) treatment and this activity was influenced by the various cotreatments in the same way as the activation by EGF. Overall, this study demonstrated that the G-protein activators thrombin and histamine inhibited both EGF- and S1P-mediated Akt phosphorylation in HUVEC by activation of PKCdelta, while the inhibitory effects of LPC were independent of PKCdelta.en
dc.language.isoenen
dc.relation.urlhttp://www.sciencedirect.com/science/article/B6T12-48JK65S-2/2/6a3cfbb8c99d7ed73cd4a1ce150835cben
dc.subject.meshCells, Cultureden
dc.subject.meshEndothelium, Vascularen
dc.subject.meshEnzyme Activationen
dc.subject.meshEpidermal Growth Factoren
dc.subject.meshHistamineen
dc.subject.meshHumansen
dc.subject.meshIsoenzymesen
dc.subject.meshLysophosphatidylcholinesen
dc.subject.meshLysophospholipidsen
dc.subject.meshMitogen-Activated Protein Kinasesen
dc.subject.meshNitric Oxide Synthaseen
dc.subject.meshNitric Oxide Synthase Type IIIen
dc.subject.meshPhospholipase C deltaen
dc.subject.meshPhosphorylationen
dc.subject.meshProtein Kinase Cen
dc.subject.meshProtein-Serine-Threonine Kinasesen
dc.subject.meshProto-Oncogene Proteinsen
dc.subject.meshProto-Oncogene Proteins c-akten
dc.subject.meshSphingosineen
dc.subject.meshThrombinen
dc.subject.meshType C Phospholipasesen
dc.titleInhibition of Akt phosphorylation by thrombin, histamine and lysophosphatidylcholine in endothelial cells. Differential role of protein kinase Cen
dc.typeArticleen
dc.identifier.journalAtherosclerosisen
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