A noble function of BAY 11-7082: Inhibition of platelet aggregation mediated by an elevated cAMP-induced VASP, and decreased ERK2/JNK1 phosphorylations

• Published in: European journal of pharmacology Vol. 627; no. 1; pp. 85 - 91
• Main Authors: Lee, Hyun-Sub, Kim, Sung Dae, Lee, Whi Min, Endale, Mehari, Kamruzzaman, S.M., Oh, Won Jun, Cho, Jae Youl, Kim, Sang Keun, Cho, Hyun-Jeong, Park, Hwa-Jin, Rhee, Man Hee
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 10.02.2010; Elsevier
• Subjects: Adenosine Triphosphate - metabolism; Animals; Anti-Inflammatory Agents - pharmacology; BAY 11-7082; Biological and medical sciences; Blood Platelets - drug effects; Blood Platelets - metabolism; Calcium - metabolism; cAMP; Cell Adhesion Molecules - metabolism; Collagen - pharmacology; Cyclic AMP - biosynthesis; Cyclic AMP - metabolism; Cyclic GMP - biosynthesis; Cyclic GMP - metabolism; Gene Expression Regulation - drug effects; Intracellular Space - drug effects; Intracellular Space - metabolism; Male; MAP kinase; Medical sciences; Microfilament Proteins - metabolism; Mitogen-Activated Protein Kinase 1 - metabolism; Mitogen-Activated Protein Kinase 8 - metabolism; NF-kappa B - metabolism; Nitriles - pharmacology; P-Selectin - metabolism; Pharmacology. Drug treatments; Phosphoproteins - metabolism; Phosphorylation - drug effects; Platelet; Platelet Aggregation - drug effects; Rats; Rats, Sprague-Dawley; Sulfones - pharmacology; Thrombin - pharmacology; Thromboxane A2 - biosynthesis; TXA 2; VASP; VASP; MAP kinase; Platelet; BAY 11-7082; cAMP; TXA 2; Phosphorylation; Enzyme; Arachidonic acid derivatives; Transferases; Thromboxane A2; Cyclic AMP; Mitogen-activated protein kinase; Aggregation; Eicosanoid; AMP-3',5'; TXA
• DOI: 10.1016/j.ejphar.2009.11.005
• ISSN: 0014-2999

Platelets, though anucleated, possess several transcription factors, including NF-κB, that exert non-genomic functions regulating platelet activation. Since platelets have not only been recognized as central players of homeostasis, but also participated in pathological conditions such as thrombosis, atherosclerosis, and inflammation, we examined rat platelet NF-κB expression and evaluated the effects of anti-inflammatory drug BAY 11-7082, an inhibitor of NF-κB activation, in platelet physiology. Western blotting revealed that rat platelets express NF-κB. BAY 11-7082, dose dependently, inhibited collagen- or thrombin-induced-platelet aggregation. ATP release, TXB 2 formation, P-selectin expression, and intercellular Ca 2+ concentration activated by collagen were reduced in BAY 11-7082-treated platelets. BAY 11-7082 elevated intracellular levels of cAMP, but not cGMP, and its co-incubation with cAMP-activating agent (forskolin) or its hydrolyzing enzyme inhibitor (3-isobutyl-1-methylxanthine, IBMX), synergistically inhibited collagen-induced-platelet aggregation. In addition, vasodilator-stimulated-phosphoprotein (VASP) phosphorylation was enhanced in BAY 11-7082-treated platelets, which was partially inhibited by a protein kinase A (PKA) inhibitor, H-89. Moreover, while p38 mitogen-activated protein kinase (MAPK) was not affected, BAY 11-7082 attenuated c-Jun N-terminal kinase 1 (JNK1) and extracellular-signal-regulated protein kinase 2 (ERK2) phosphorylations. In conclusion, BAY 11-7082 inhibits platelet activation, granule secretion, and aggregation, and that this effect is mediated by inhibition of JNK1 and ERK2 phosphorylations, and partially by stimulation of cAMP-dependent PKA VASP phosphorylation. The ability of BAY 11-7082 to inhibit platelet function might be relevant in cases involving aberrant platelet activation where the drug is considered as anti-atherothrombosis, and anti-inflammatory therapy.