Acute tissue-type plasminogen activator release in human microvascular endothelial cells: The roles of Gαq, PLC-β, IP3 and 5,6-epoxyeicosatrienoic acid
| Autor: | Douglas E. Vaughan, Elaine Sanders-Bush, Nancy J. Brown, Corrie A. Painter, James A.S. Muldowney |
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| Rok vydání: | 2007 |
| Předmět: |
medicine.medical_specialty
Endothelium T-plasminogen activator Prostacyclin Hematology Biology Apamin Epoxyeicosatrienoic acid Nitric oxide Endothelial stem cell chemistry.chemical_compound Endocrinology medicine.anatomical_structure chemistry Internal medicine cardiovascular system medicine Plasminogen activator medicine.drug |
| Zdroj: | Thrombosis and Haemostasis. 97:263-271 |
| ISSN: | 2567-689X 0340-6245 |
| Popis: | SummaryThe acute physiologic release of tissue-type plasminogen activator (t-PA) from the endothelium is critical for vascular homeostasis. This process is prostacyclin- and nitric oxide (NO)-independent in humans. It has been suggested that calcium signaling and endothelial-derived hyperpolarizing factors (EDHF) may play a role in t-PA release. G-protein-coupled receptor-dependent calcium signaling is typically Gαq -dependent. EDHFs have been functionally defined and in various tissues are believed to be various regioisomers of the epoxyeicosatrienoic acids (EETs). We tested the hypothesis in vitrothat thrombin-stimulated t-PA release from human microvascular endothelial cells (HMECs) is both Gαq - and EDHF-dependent. Conditioned media was harvested following thrombin stimulation, and t-PA antigen was measured by ELISA. Thrombin-induced t-PA release was limited by a membrane-permeable Gαq inhibitory peptide, the PLC-β antagonist U73122, and the IP3 receptor antagonist 2-aminoethoxyphenylborane, while the Gαq agonist Pasteurellatoxin modestly induced t-PA release. The cytochrome P450 (CYP450) inhibitor, miconazole, and the arachidonic acid epoxygenase inhibitor MS-PPOH inhibited thrombin-stimulated t-PA release, while 5,6-EET-methyl ester stimulated t-PA release. The 5,6- and 14,15-EET antagonist, 14,15-epoxyeicosa-5(Z)- enoic acid, inhibited t-PA release at the 100 µM concentration. However, thrombin-stimulated t-PA release was unaffected by the prostacyclin and NO inhibitors ASA and L-NAME, as well as the potassium channel inhibitors TEA, apamin and charybdotoxin. These studies suggest that thrombin-stimulated t-PA release is Gαq-, PLC-β -, IP3 -, and 5,6-EET-dependent while being prostacyclin-, NO- and K + channel-independent in HMECs. |
| Databáze: | OpenAIRE |
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