Abstract
Previous studies have demonstrated an inhibition of agonist-induced inositol phospholipid breakdown and intracellular Ca2+ ([Ca2+]i) mobilization by phorbol esters in platelets. In this study, we have examined the effect of phorbol 12-myristate 13-acetate (PMA) on agonist-induced granule secretion and correlated it with agonist-induced [Ca2+]i mobilization, arachidonate and thromboxane (Tx) release in human platelets. With increasing times of incubation with PMA (10 s-5 min), the rise in [Ca2+]i induced by thrombin and the TxA2 mimetic, U46619, was increasingly inhibited (90-100% with 5 min incubation) and, correlating with this, thrombin-induced [3H]arachidonate, TxB2 and beta-thromboglobulin (beta TG) release were also inhibited. In addition, the conversion of exogenously added arachidonate to TxB2 was inhibited (50-80%) by a 10 s-5 min pretreatment with PMA. However, secretion of 5-hydroxy[14C]tryptamine (5HT) induced by thrombin or U46619 was not inhibited by 10 s-2 min incubations with PMA and, on the contrary, with low agonist concentrations, was potentiated by PMA in the absence of a significant rise in [Ca2+]i or endogenous Tx formation, to levels significantly greater than or equal to the sum of that obtained when agonist and PMA were added separately. With longer times of incubation with PMA (5 min), these synergistic effects became less pronounced as inhibitory effects of PMA on agonist-induced [14C]5HT secretion became apparent. The results indicate that, while PMA may cause an inhibition of agonist-induced [Ca2+]i mobilization resulting in an inhibition of agonist-induced arachidonate, TxB2 and beta TG release, its effects on agonist-induced 5HT secretion may be complicated by [Ca2+]i-independent synergistic effects of agonist and PMA.
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Selected References
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- Authi K. S., Crawford N. Inositol 1,4,5-trisphosphate-induced release of sequestered Ca2+ from highly purified human platelet intracellular membranes. Biochem J. 1985 Aug 15;230(1):247–253. doi: 10.1042/bj2300247. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Begg G. S., Pepper D. S., Chesterman C. N., Morgan F. J. Complete covalent structure of human beta-thromboglobulin. Biochemistry. 1978 May 2;17(9):1739–1744. doi: 10.1021/bi00602a024. [DOI] [PubMed] [Google Scholar]
- Berridge M. J. Inositol trisphosphate and diacylglycerol as second messengers. Biochem J. 1984 Jun 1;220(2):345–360. doi: 10.1042/bj2200345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berridge M. J., Irvine R. F. Inositol trisphosphate, a novel second messenger in cellular signal transduction. Nature. 1984 Nov 22;312(5992):315–321. doi: 10.1038/312315a0. [DOI] [PubMed] [Google Scholar]
- Bills T. K., Smith J. B., Silver M. J. Metabolism of [14C]arachidonic acid by human platelets. Biochim Biophys Acta. 1976 Feb 23;424(2):303–314. doi: 10.1016/0005-2760(76)90198-3. [DOI] [PubMed] [Google Scholar]
- Blackwell G. J., Flower R. J. 1-Phenyl-3-pyrazolidone: an inhibitor of arachidonate oxidation in lung and platelets [proceedings]. Br J Pharmacol. 1978 Jun;63(2):360P–360P. [PMC free article] [PubMed] [Google Scholar]
- Brock T. A., Rittenhouse S. E., Powers C. W., Ekstein L. S., Gimbrone M. A., Jr, Alexander R. W. Phorbol ester and 1-oleoyl-2-acetylglycerol inhibit angiotensin activation of phospholipase C in cultured vascular smooth muscle cells. J Biol Chem. 1985 Nov 15;260(26):14158–14162. [PubMed] [Google Scholar]
- Castagna M., Takai Y., Kaibuchi K., Sano K., Kikkawa U., Nishizuka Y. Direct activation of calcium-activated, phospholipid-dependent protein kinase by tumor-promoting phorbol esters. J Biol Chem. 1982 Jul 10;257(13):7847–7851. [PubMed] [Google Scholar]
- Heyworth C. M., Whetton A. D., Kinsella A. R., Houslay M. D. The phorbol ester, TPA inhibits glucagon-stimulated adenylate cyclase activity. FEBS Lett. 1984 May 7;170(1):38–42. doi: 10.1016/0014-5793(84)81364-2. [DOI] [PubMed] [Google Scholar]
- Hokin L. E. Receptors and phosphoinositide-generated second messengers. Annu Rev Biochem. 1985;54:205–235. doi: 10.1146/annurev.bi.54.070185.001225. [DOI] [PubMed] [Google Scholar]
- Jakobs K. H., Bauer S., Watanabe Y. Modulation of adenylate cyclase of human platelets by phorbol ester. Impairment of the hormone-sensitive inhibitory pathway. Eur J Biochem. 1985 Sep 2;151(2):425–430. doi: 10.1111/j.1432-1033.1985.tb09119.x. [DOI] [PubMed] [Google Scholar]
- Katada T., Gilman A. G., Watanabe Y., Bauer S., Jakobs K. H. Protein kinase C phosphorylates the inhibitory guanine-nucleotide-binding regulatory component and apparently suppresses its function in hormonal inhibition of adenylate cyclase. Eur J Biochem. 1985 Sep 2;151(2):431–437. doi: 10.1111/j.1432-1033.1985.tb09120.x. [DOI] [PubMed] [Google Scholar]
- Knight D. E., Scrutton M. C. Cyclic nucleotides control a system which regulates Ca2+ sensitivity of platelet secretion. Nature. 1984 May 3;309(5963):66–68. doi: 10.1038/309066a0. [DOI] [PubMed] [Google Scholar]
- Krishnamurthi S., Joseph S. K., Kakkar V. V. Lack of inhibition of thrombin-induced rise in intracellular Ca2+ levels and 5-hydroxytryptamine secretion by 1-oleoyl-2-acetylglycerol in human platelets. FEBS Lett. 1986 Feb 17;196(2):365–369. doi: 10.1016/0014-5793(86)80281-2. [DOI] [PubMed] [Google Scholar]
- Krishnamurthi S., Westwick J., Kakkar V. V. Regulation of human platelet activation--analysis of cyclooxygenase and cyclic AMP-dependent pathways. Biochem Pharmacol. 1984 Oct 1;33(19):3025–3035. doi: 10.1016/0006-2952(84)90604-x. [DOI] [PubMed] [Google Scholar]
- Lagast H., Pozzan T., Waldvogel F. A., Lew P. D. Phorbol myristate acetate stimulates ATP-dependent calcium transport by the plasma membrane of neutrophils. J Clin Invest. 1984 Mar;73(3):878–883. doi: 10.1172/JCI111284. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lynch C. J., Charest R., Bocckino S. B., Exton J. H., Blackmore P. F. Inhibition of hepatic alpha 1-adrenergic effects and binding by phorbol myristate acetate. J Biol Chem. 1985 Mar 10;260(5):2844–2851. [PubMed] [Google Scholar]
- MacIntyre D. E., McNicol A., Drummond A. H. Tumour-promoting phorbol esters inhibit agonist-induced phosphatidate formation and Ca2+ flux in human platelets. FEBS Lett. 1985 Jan 28;180(2):160–164. doi: 10.1016/0014-5793(85)81063-2. [DOI] [PubMed] [Google Scholar]
- Naccache P. H., Molski M. M., Volpi M., Becker E. L., Sha'afi R. I. Unique inhibitory profile of platelet activating factor induced calcium mobilization, polyphosphoinositide turnover and granule enzyme secretion in rabbit neutrophils towards pertussis toxin and phorbol ester. Biochem Biophys Res Commun. 1985 Jul 31;130(2):677–684. doi: 10.1016/0006-291x(85)90470-x. [DOI] [PubMed] [Google Scholar]
- Nishizuka Y. The role of protein kinase C in cell surface signal transduction and tumour promotion. Nature. 1984 Apr 19;308(5961):693–698. doi: 10.1038/308693a0. [DOI] [PubMed] [Google Scholar]
- O'Rourke F. A., Halenda S. P., Zavoico G. B., Feinstein M. B. Inositol 1,4,5-trisphosphate releases Ca2+ from a Ca2+-transporting membrane vesicle fraction derived from human platelets. J Biol Chem. 1985 Jan 25;260(2):956–962. [PubMed] [Google Scholar]
- Rink T. J., Sanchez A., Hallam T. J. Diacylglycerol and phorbol ester stimulate secretion without raising cytoplasmic free calcium in human platelets. Nature. 1983 Sep 22;305(5932):317–319. doi: 10.1038/305317a0. [DOI] [PubMed] [Google Scholar]
- Rittenhouse S. E., Sasson J. P. Mass changes in myoinositol trisphosphate in human platelets stimulated by thrombin. Inhibitory effects of phorbol ester. J Biol Chem. 1985 Jul 25;260(15):8657–8660. [PubMed] [Google Scholar]
- Tsien R. Y., Pozzan T., Rink T. J. Calcium homeostasis in intact lymphocytes: cytoplasmic free calcium monitored with a new, intracellularly trapped fluorescent indicator. J Cell Biol. 1982 Aug;94(2):325–334. doi: 10.1083/jcb.94.2.325. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Watson S. P., Lapetina E. G. 1,2-Diacylglycerol and phorbol ester inhibit agonist-induced formation of inositol phosphates in human platelets: possible implications for negative feedback regulation of inositol phospholipid hydrolysis. Proc Natl Acad Sci U S A. 1985 May;82(9):2623–2626. doi: 10.1073/pnas.82.9.2623. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Whiteley B., Deuel T., Glaser L. Modulation of the activity of the platelet-derived growth factor receptor by phorbol myristate acetate. Biochem Biophys Res Commun. 1985 Jun 28;129(3):854–861. doi: 10.1016/0006-291x(85)91970-9. [DOI] [PubMed] [Google Scholar]
- Zavoico G. B., Halenda S. P., Sha'afi R. I., Feinstein M. B. Phorbol myristate acetate inhibits thrombin-stimulated Ca2+ mobilization and phosphatidylinositol 4,5-bisphosphate hydrolysis in human platelets. Proc Natl Acad Sci U S A. 1985 Jun;82(11):3859–3862. doi: 10.1073/pnas.82.11.3859. [DOI] [PMC free article] [PubMed] [Google Scholar]
- de Chaffoy de Courcelles D., Roevens P., van Belle H. 12-O-Tetradecanoylphorbol 13-acetate stimulates inositol lipid phosphorylation in intact human platelets. FEBS Lett. 1984 Aug 6;173(2):389–393. doi: 10.1016/0014-5793(84)80811-x. [DOI] [PubMed] [Google Scholar]