title: Caffeine induces endothelial tissue factor expression via phosphatidylinositol 3-kinase inhibition.
abstract: Tissue factor (TF) is the key activator of coagulation and is involved in acute coronary syndromes. Caffeine is often reported to increase cardiovascular risk; however, its effect on cardiovascular morbidity and mortality is controversial. Hence, this study was designed to investigate the impact of caffeine on endothelial TF expression in vitro. Caffeine concentration-dependently enhanced TF protein expression and surface activity in human endothelial cells stimulated by tumour necrosis factor (TNF)-α or thrombin. Caffeine inhibited phosphatidylinositol 3-kinase (PI3K) activity and this effect was comparable to that of the known PI3K inhibitor LY294002. Consistently, treatment of endothelial cells with LY294002 enhanced TNF-α induced TF expression to a similar extent as caffeine, and adenoviral expression of the active PI3K mutant (p110) reversed the effect of both caffeine and LY294002 on TF expression. Caffeine and LY294002 increased DNA binding capacity of the transcription factor nuclear factor κB, whereas the activation pattern of mitogen-activated protein kinases (MAPK) remained unaltered. Luciferase reporter assay revealed a caffeine dependent activation of the TF promoter, and RT-PCR revealed a dose dependent increase in TF mRNA levels when stimulated with caffeine in the presence of TNF-α. In conclusion, caffeine enhances TNF-α-induced endothelial TF protein expression as well as surface activity by inhibition of PI3K signalling. Since the caffeine concentrations applied in the present study are within the plasma range measured in humans, our findings indicate that caffeine enhances the prothrombotic potential of endothelial cells and underscore the importance of PI3K in mediating these effects.
authors.affiliation: Cardiovascular Research, Physiology Institute, University of Zurich, Zurich, Switzerland.
authors.forename: Cathérine
authors.initials: C
authors.lastname: Gebhard
authors.forename: Erik W
authors.initials: EW
authors.lastname: Holy
authors.forename: Giovanni G
authors.initials: GG
authors.lastname: Camici
authors.forename: Alexander
authors.initials: A
authors.lastname: Akhmedov
authors.forename: Simon F
authors.initials: SF
authors.lastname: Stämpfli
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Stähli
authors.forename: Bettina
authors.initials: B
authors.lastname: von Rickenbach
authors.forename: Alexander
authors.initials: A
authors.lastname: Breitenstein
authors.forename: Helen
authors.initials: H
authors.lastname: Greutert
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Yang
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Lüscher
authors.forename: Felix C
authors.initials: FC
authors.lastname: Tanner
mesh_terms: D001665:Binding Sites; D002110:Caffeine / Q000494:pharmacology*; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000201:enzymology; D004789:Enzyme Activation; D006801:Humans; D008074:Lipoproteins / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism; D058539:Phosphatidylinositol 3-Kinase / Q000235:genetics / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011401:Promoter Regions, Genetic; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D058915:Purinergic P1 Receptor Antagonists / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D018047:Receptors, Purinergic P1 / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013917:Thrombin / Q000378:metabolism; D013925:Thromboplastin / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D002867:Chromones; D008074:Lipoproteins; D009025:Morpholines; D016328:NF-kappa B; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D058915:Purinergic P1 Receptor Antagonists; D012333:RNA, Messenger; D018047:Receptors, Purinergic P1; D014409:Tumor Necrosis Factor-alpha; C051928:lipoprotein-associated coagulation inhibitor; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D002110:Caffeine; D004247:DNA; D013925:Thromboplastin; D058539:Phosphatidylinositol 3-Kinase; D020928:Mitogen-Activated Protein Kinases; D013917:Thrombin