Abstract
The effects of phorbol 12-myristate 13-acetate (PMA), a potent activator of protein kinase C, on Na+ influx were investigated in cultured human foreskin fibroblasts (HSWP cells). We report here that in serum-deprived HSWP cells the addition of PMA alone has no significant effect on Na+ influx. However, the addition of PMA to cells whose Na+/H+ exchanger is partially activated with a submaximal dose of the Ca2+ ionophore A23187 leads to a larger stimulation than seen with A23187 alone. These data suggest that although stimulation of protein kinase C is not a sufficient signal to activate the Na+/H+ exchanger in HSWP cells or in another human foreskin line (Jackson fibroblasts) studied, there are some cooperative effects of protein kinase C activation with a rise in Ca2+ to stimulate Na+/H+ exchange. In addition, we found that PMA actually inhibits the mitogen-induced stimulation of Na+ influx in HSWP and Jackson fibroblasts. This observation strengthens the argument that in these cells activation of protein kinase C is not sufficient to activate Na+/H+ exchange and suggests that there is a negative feedback control via protein kinase C that inhibits some signal that is necessary for activating Na+/H+ exchange. However, in contrast to observations in HSWP cells, we were able to activate the Na+/H+ exchanger in mouse 3T3 and human WI-38 cells with PMA alone, suggesting that there is some diversity in the mechanism for activation of Na+/H+ exchange in different types of fibroblasts.
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- Davis B. A., Schwartz A., Samaha F. J., Kranias E. G. Regulation of cardiac sarcoplasmic reticulum calcium transport by calcium-calmodulin-dependent phosphorylation. J Biol Chem. 1983 Nov 25;258(22):13587–13591. [PubMed] [Google Scholar]
- Dicker P., Rozengurt E. Phorbol ester stimulation of Na influx and Na-K pump activity in Swiss 3T3 cells. Biochem Biophys Res Commun. 1981 May 15;100(1):433–441. doi: 10.1016/s0006-291x(81)80115-5. [DOI] [PubMed] [Google Scholar]
- Fain J. N., Li S. Y., Litosch I., Wallace M. Synergistic activation of rat hepatocyte glycogen phosphorylase by A23187 and phorbol ester. Biochem Biophys Res Commun. 1984 Feb 29;119(1):88–94. doi: 10.1016/0006-291x(84)91622-x. [DOI] [PubMed] [Google Scholar]
- Friedman B., Frackelton A. R., Jr, Ross A. H., Connors J. M., Fujiki H., Sugimura T., Rosner M. R. Tumor promoters block tyrosine-specific phosphorylation of the epidermal growth factor receptor. Proc Natl Acad Sci U S A. 1984 May;81(10):3034–3038. doi: 10.1073/pnas.81.10.3034. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hesketh T. R., Moore J. P., Morris J. D., Taylor M. V., Rogers J., Smith G. A., Metcalfe J. C. A common sequence of calcium and pH signals in the mitogenic stimulation of eukaryotic cells. Nature. 1985 Feb 7;313(6002):481–484. doi: 10.1038/313481a0. [DOI] [PubMed] [Google Scholar]
- Mix L. L., Dinerstein R. J., Villereal M. L. Mitogens and melittin stimulate an increase in intracellular free calcium concentration in human fibroblasts. Biochem Biophys Res Commun. 1984 Feb 29;119(1):69–75. doi: 10.1016/0006-291x(84)91619-x. [DOI] [PubMed] [Google Scholar]
- Moolenaar W. H., Tertoolen L. G., de Laat S. W. Phorbol ester and diacylglycerol mimic growth factors in raising cytoplasmic pH. Nature. 1984 Nov 22;312(5992):371–374. doi: 10.1038/312371a0. [DOI] [PubMed] [Google Scholar]
- Moolenaar W. H., Tsien R. Y., van der Saag P. T., de Laat S. W. Na+/H+ exchange and cytoplasmic pH in the action of growth factors in human fibroblasts. Nature. 1983 Aug 18;304(5927):645–648. doi: 10.1038/304645a0. [DOI] [PubMed] [Google Scholar]
- Muldoon L. L., Dinerstein R. J., Villereal M. L. Intracellular pH in human fibroblasts: effect of mitogens, A23187, and phospholipase activation. Am J Physiol. 1985 Jul;249(1 Pt 1):C140–C148. doi: 10.1152/ajpcell.1985.249.1.C140. [DOI] [PubMed] [Google Scholar]
- Naka M., Nishikawa M., Adelstein R. S., Hidaka H. Phorbol ester-induced activation of human platelets is associated with protein kinase C phosphorylation of myosin light chains. Nature. 1983 Dec 1;306(5942):490–492. doi: 10.1038/306490a0. [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]
- Owen N. E., Villereal M. L. Effect of the intracellular Ca+2 antagonist TMB-8 on serum-stimulated Na+ influx in human fibroblasts. Biochem Biophys Res Commun. 1982 Dec 15;109(3):762–768. doi: 10.1016/0006-291x(82)92005-8. [DOI] [PubMed] [Google Scholar]
- Owen N. E., Villereal M. L. Evidence for a role of calmodulin in serum stimulation of Na+ influx in human fibroblasts. Proc Natl Acad Sci U S A. 1982 Jun;79(11):3537–3541. doi: 10.1073/pnas.79.11.3537. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pouysségur J., Chambard J. C., Franchi A., Paris S., Van Obberghen-Schilling E. Growth factor activation of an amiloride-sensitive Na+/H+ exchange system in quiescent fibroblasts: coupling to ribosomal protein S6 phosphorylation. Proc Natl Acad Sci U S A. 1982 Jul;79(13):3935–3939. doi: 10.1073/pnas.79.13.3935. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pozzan T., Gatti G., Dozio N., Vicentini L. M., Meldolesi J. Ca2+-dependent and -independent release of neurotransmitters from PC12 cells: a role for protein kinase C activation? J Cell Biol. 1984 Aug;99(2):628–638. doi: 10.1083/jcb.99.2.628. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith J. B., Rozengurt E. Serum stimulates the Na+,K+ pump in quiescent fibroblasts by increasing Na+ entry. Proc Natl Acad Sci U S A. 1978 Nov;75(11):5560–5564. doi: 10.1073/pnas.75.11.5560. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Takayama S., White M. F., Lauris V., Kahn C. R. Phorbol esters modulate insulin receptor phosphorylation and insulin action in cultured hepatoma cells. Proc Natl Acad Sci U S A. 1984 Dec;81(24):7797–7801. doi: 10.1073/pnas.81.24.7797. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vicentini L. M., Di Virgilio F., Ambrosini A., Pozzan T., Meldolesi J. Tumor promoter phorbol 12-myristate, 13-acetate inhibits phosphoinositide hydrolysis and cytosolic Ca2+ rise induced by the activation of muscarinic receptors in PC12 cells. Biochem Biophys Res Commun. 1985 Feb 28;127(1):310–317. doi: 10.1016/s0006-291x(85)80160-1. [DOI] [PubMed] [Google Scholar]
- Vicentini L. M., Villereal M. L. Serum, bradykinin and vasopressin stimulate release of inositol phosphates from human fibroblasts. Biochem Biophys Res Commun. 1984 Sep 17;123(2):663–670. doi: 10.1016/0006-291x(84)90280-8. [DOI] [PubMed] [Google Scholar]
- Villereal M. L. Sodium fluxes in human fibroblasts: effect of serum, Ca+2, and amiloride. J Cell Physiol. 1981 Jun;107(3):359–369. doi: 10.1002/jcp.1041070307. [DOI] [PubMed] [Google Scholar]
- Whiteley B., Cassel D., Zhuang Y. X., Glaser L. Tumor promoter phorbol 12-myristate 13-acetate inhibits mitogen-stimulated Na+/H+ exchange in human epidermoid carcinoma A431 cells. J Cell Biol. 1984 Sep;99(3):1162–1166. doi: 10.1083/jcb.99.3.1162. [DOI] [PMC free article] [PubMed] [Google Scholar]