title: 2-(2,4-dihydroxyphenyl)-5-(E)-propenylbenzofuran promotes endothelial nitric oxide synthase activity in human endothelial cells.
abstract: Endothelial nitric oxide synthase (eNOS) mediates important vaso-protective and immunomodulatory effects. Aim of this study was to examine whether lignan derivatives isolated from the roots of the anti-inflammatory medicinal plant Krameria lappacea influence eNOS activity and endothelial nitric oxide (NO) release. The study was performed using cultured human umbilical vein endothelial cells (HUVECs) and HUVEC-derived EA.hy926 cells. Among the eleven isolated compounds only 2-(2,4-dihydroxyphenyl)-5-(E)-propenylbenzofuran (DPPB) was able to increase eNOS enzyme activity. DPPB (1-10 μM) treatment for 24 h induced a significant and dose-dependent increase in eNOS activity as determined by the [(14)C]L-arginine/[(14)C]L-citrulline conversion assay. Immunoblotting studies further revealed a time-dependent DPPB-induced increase in eNOS-Ser(1177) and decrease in eNOS-Thr(495) phosphorylation, as well as increased AMPK phosphorylation at Thr(172), whereas Akt phosphorylation at Ser(473) was not affected. Si-RNA-mediated knockdown of AMPK and inhibition of CaMKKβ by STO 609, as well as intracellular Ca(2+) chelation by Bapta AM abolished the stimulating effect of DPPB on eNOS-Ser(1177) and AMPK-Thr(172) phosphorylation. Furthermore, we could show that DPPB increases intracellular Ca(2+) concentrations assessed with the fluorescent dye Fluo-3-AM. DPPB enhances eNOS activity and endothelial NO release by raising intracellular Ca(2+) levels and increases signaling through a CaMKKβ-AMPK dependent pathway.
authors: Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. angela.ladurner@univie.ac.at
authors: Angela
authors: A
authors: Ladurner
authors: Atanas G
authors: AG
authors: Atanasov
authors: Elke H
authors: EH
authors: Heiss
authors: Lisa
authors: L
authors: Baumgartner
authors: Stefan
authors: S
authors: Schwaiger
authors: Judith M
authors: JM
authors: Rollinger
authors: Hermann
authors: H
authors: Stuppner
authors: Verena M
authors: VM
authors: Dirsch
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology; D005663:Furans / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D031326:Krameriaceae; D017705:Lignans / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: C458561:2-(2,4-dihydroxyphenyl)-5-propenylbenzofuran; D002614:Chelating Agents; D005663:Furans; D017705:Lignans; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D051057:Proto-Oncogene Proteins c-akt; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D055372:AMP-Activated Protein Kinases; D002118:Calcium