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Badmaev V, Prakash S, Majeed M. Vanadium: a review of its potential role in the fight against diabetes. J Altern Complement Med 1999; 5:273-91. [PMID: 10381252 DOI: 10.1089/acm.1999.5.273] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The potential role of vanadium in human health is described as a building material of bones and teeth. However, another very interesting and promising application for vanadium in human health emerges from recent studies that evaluated the role of vanadium in the management of diabetes. Vanadium is present in a variety of foods that we commonly eat. Skim milk, lobster, vegetable oils, many vegetables, grains and cereals are rich source of vanadium (>1 ppm). Fruits, meats, fish, butter, cheese, and beverages are relatively poor sources of vanadium. The daily dietary intake in humans has been estimated to vary from 10 microg to 2 mg of elemental vanadium, depending on the environmental sources of this mineral in the air, water, and food of the particular region tested. In animals, vanadium has been shown essential (1-10 microg vanadium per gram of diet). There is only circumstantial evidence that vanadium is essential for humans. However, in doses ranging from 0.083 mmol/d to 0.42 mmol/d, vanadium has shown therapeutic potential in clinical studies with patients of both insulin-dependent diabetes mellitus (IDDM) and noninsulin-dependent diabetes mellitus (NIDDM) type. Although vanadium has a significant biological potential, it has a poor therapeutic index, and attempts have been made to reduce the dose of vanadium required for therapeutic effectiveness. Organic forms of vanadium, as opposed to the inorganic sulfate salt of vanadium, are recognized as safer, more absorbable, and able to deliver a therapeutic effect up to 50% greater than the inorganic forms. The goal is to provide vanadium with better gastrointestinal absorption, and in a form that is best able to produce the desired biological effects. As a result, numerous organic complexes of vanadium have been developed including bis(maltolato)oxovanadium (BMOV), bis(cysteinamide N-octyl)oxovanadium known as Naglivan, bis(pyrrolidine-N-carbodithioato)oxovanadium, vanadyl-cysteine methyl ester, and bis-glycinato oxovanadium (BGOV). The health benefits of vanadium and the safety and efficacy of the available vanadium supplements are discussed in this review.
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Affiliation(s)
- V Badmaev
- Sabinsa Corporation, Piscataway, New Jersey 08854, USA.
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Mandell JW, Banker GA. Selective blockade of axonogenesis in cultured hippocampal neurons by the tyrosine phosphatase inhibitor orthovanadate. JOURNAL OF NEUROBIOLOGY 1998; 35:17-28. [PMID: 9552163 DOI: 10.1002/(sici)1097-4695(199804)35:1<17::aid-neu2>3.0.co;2-e] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protein tyrosine phosphorylation has been implicated in several aspects of neurite outgrowth regulation. To address specific roles in early neuronal morphogenesis, hippocampal neurons in culture were treated with the tyrosine phosphatase inhibitor orthovanadate. This treatment completely suppressed axon formation, yet enhanced formation of minor neurites. The inhibition of axonogenesis was dose dependent and occurred in parallel with a marked increase in cellular phosphotyrosine immunoreactivity, which was especially concentrated within neuritic growth cones and showed partial colocalization with f-actin. Both the blockade of axonogenesis and the elevation of phosphotyrosine were completely reversible. An additional and unexpected effect of orthovanadate was the appearance of many binucleate neurons. Immunoblotting experiments using a phosphotyrosine-specific antibody revealed an orthovanadate-induced reversible hyperphosphorylation of several protein bands, especially of two at 115 and 125 kD. These data suggest a potentially important role for tyrosine phosphatases and their phosphoprotein substrates in axonogenesis.
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Affiliation(s)
- J W Mandell
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville 22908, USA
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3
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Abstract
The aim of this study was to define the effects of a potent inhibitor of tyrosine phosphatases, sodium orthovanadate (0.1-100 microM for up to 48 h), on dentate gyrus cells (DGC) in culture. Treatment with 100 microM orthovanadate evoked a delayed form of cell death. To examine the possible involvement of apoptosis in orthovanadate-induced cell death, biochemical and morphological alterations were compared with those of necrotic death induced by sodium azide. Phase-contrast microscopy and nuclear condensation analysis showed that orthovanadate and azide each evoked cell death by distinct pathways. TUNEL assay was positive in both cases. Application of a protein synthesis inhibitor, cycloheximide, did not prevent cytotoxicity caused by either orthovanadate or azide and potentiated the effects of vanadate. We conclude that orthovanadate-induced death of DGC bears features of apoptosis.
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Affiliation(s)
- I Figiel
- Nencki Institute, Warsaw, Poland
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4
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Williams B, Howard RL. Glucose-induced changes in Na+/H+ antiport activity and gene expression in cultured vascular smooth muscle cells. Role of protein kinase C. J Clin Invest 1994; 93:2623-31. [PMID: 8201001 PMCID: PMC294501 DOI: 10.1172/jci117275] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Increased Na+/H+ antiport activity has been implicated in the pathogenesis of hypertension and vascular disease in diabetes mellitus. The independent effect of elevated extracellular glucose concentrations on Na+/H+ antiport activity in cultured rat vascular smooth muscle cells (VSMC) was thus examined. Amiloride-sensitive 22Na+ uptake by VSMC significantly increased twofold after 3 and 24 h of exposure to high glucose medium (20 mM) vs. control medium (5 mM). Direct glucose-induced Na+/H+ antiport activation was confirmed by measuring Na(+)-dependent intracellular pH recovery from intracellular acidosis. High glucose significantly increased protein kinase C (PKC) activity in VSMC and inhibition of PKC activation with H-7, staurosporine, or prior PKC downregulation prevented glucose-induced increases in Na+/H+ antiport activity in VSMC. Northern analysis of VSMC poly A+ RNA revealed that high glucose induced a threefold increase in Na+/H+ antiport (NHE-1) mRNA at 24 h. Inhibiting this increase in NHE-1 mRNA with actinomycin D prevented the sustained glucose-induced increase in Na+/H+ antiport activity. In conclusion, elevated glucose concentrations significantly influence vascular Na+/H+ antiport activity via glucose-induced PKC dependent mechanisms, thereby providing a biochemical basis for increased Na+/H+ antiport activity in the vascular tissues of patients with hypertension and diabetes mellitus.
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Affiliation(s)
- B Williams
- Department of Medicine, University of Leicester School of Medicine, United Kingdom
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5
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Wu YY, Bradshaw RA. Effect of nerve growth factor and fibroblast growth factor on PC12 cells: inhibition by orthovanadate. J Cell Biol 1993; 121:409-22. [PMID: 8468355 PMCID: PMC2200105 DOI: 10.1083/jcb.121.2.409] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Sodium orthovanadate, an inhibitor of protein tyrosine phosphatases, causes increased levels of tyrosine phosphorylation and blocks, at noncytotoxic concentrations, the differentiative response of rat pheochromocytoma (PC12) cells to beta-nerve growth factor (beta NGF) and basic fibroblast growth factor (bFGF) in a reversible manner. It also prevents growth factor-induced neurite proliferation in primed cells and causes the retraction of previously formed neurites, even in the presence of beta NGF or bFGF. It is equally effective in blocking neurite proliferation by 8-Br-cAMP. Zinc chloride and ammonium molybdate, two other inhibitors of tyrosine phosphatases, also cause parallel decreases in neurite proliferation. Orthovanadate generally reduces the transcription of immediate early response genes (TIS 8 and c-fos) and secondary response genes (ornithine decarboxylase (ODC), acetyl-cholinesterase (AChE) and SCG 10) induced by beta NGF, bFGF, EGF, and PMA, albeit in a variable fashion. There was no observed effect on the kinetics of expression as judged by TIS 8 induction by beta NGF and protein kinase C (PKC) downregulation did not change the levels of inhibition by orthovanadate seen in control cells. Orthovanadate does not affect the production of diacylglycerol induced by beta NGF or bFGF. These observations are consistent with the view that growth factor stimulation of differentiation in PC12 cells involves at least one other PKC independent pathway, and that cAMP and PMA (and their active analogs) activate tyrosine kinases (albeit probably secondarily), which are at least partially responsible for their actions. Although the exact site(s) of action of orthovanadate that lead to the inhibition of growth factor-induced neurite proliferation are unknown, the results presented suggest that it prolongs tyrosine phosphorylations by nonreceptor tyrosine kinases that act downstream from the receptor kinases.
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Affiliation(s)
- Y Y Wu
- Department of Biological Chemistry, College of Medicine, University of California, Irvine 92717
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6
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8
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Shier WT, DuBourdieu DJ. Sodium- and calcium-dependent steps in the mechanism of neonatal rat cardiac myocyte killing by ionophores. I. The sodium-carrying ionophore, monensin. Toxicol Appl Pharmacol 1992; 116:38-46. [PMID: 1529451 DOI: 10.1016/0041-008x(92)90142-f] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Toxicosis by monensin, a Na(+)-selective ionophore, induces skeletal and cardiac muscle necrosis. Cultured neonatal rat cardiac myocytes were killed by monensin (greater than 0.2 micrograms/ml) beginning at 30 min and completing by 60-90 min. Other cultured cell types presumably lacking excitable membranes were not killed by monensin under these conditions. Cardiac myocytes were also killed by nigericin and nonactin (monovalent cation-carrying ionophores with low ion selectivity), but not by valinomycin, which has a high selectivity for K+. Monensin-induced killing was associated with formation of blebs in cell membranes and subsequent swelling of the cells during the early phases of killing, whereas surface membranes of cells permeabilized to trypan blue dye contained discrete small holes visible by scanning electron microscopy. Monensin-induced killing occurred at extracellular Na+ concentrations greater than or equal to 10 mM, but not when Li+, K+, Cs+, Rb+, or choline ions replaced Na+ at concentrations up to 0.15 M. Killing was prevented at extracellular pH values less than or equal to 6.4 and was enhanced by ouabain, an inhibitor of Na+/K(+)-ATPase-mediated Na+ transport. Several characteristics of monensin-induced cardiac myocyte killing were similar to those observed during killing induced by the Ca(2+)-carrying ionophore, A23187 plus Ca2+, including a requirement for extracellular Ca2+ concentrations greater than 0.5 mM, inhibition by Mn2+ and Ni2+, and an associated stimulation of arachidonic acid release. The cell killing characteristics are consistent with a monensin-induced Na+ influx which admits toxic levels of extracellular Ca2+ to the cytoplasm of cells with excitable membranes, possibly via Na+/Ca2+ antiporter protein(s).
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Affiliation(s)
- W T Shier
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis 55455
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9
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Muñoz P, Gumà A, Camps M, Furriols M, Testar X, Palacín M, Zorzano A. Vanadate stimulates system A amino acid transport activity in skeletal muscle. Evidence for the involvement of intracellular pH as a mediator of vanadate action. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50030-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Huang NN, Ahmed AH, Wang DJ, Heppel LA. Extracellular ATP stimulates increases in Na+/K+ pump activity, intracellular pH and uridine uptake in cultures of mammalian cells. Biochem Biophys Res Commun 1992; 182:836-43. [PMID: 1310399 DOI: 10.1016/0006-291x(92)91808-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Using 3T3 and 3T6 mouse fibroblasts and A431 epidermoid carcinoma cells, we previously observed that extracellular ATP and ADP were mitogens and they synergized with other growth factors (Huang, N., Wang, D. and Heppel, L. A. (1989) Proc. Natl. Acad. Sci. USA 86, 7904-7908). We now report that ATP and ADP stimulated Na+ entry, intracellular alkalinization and Na+/K+ pump activity, which are early events that had been proposed to play a central role in DNA synthesis. In addition, ATP, ADP and AMPPNP stimulated uridine uptake by a pathway involving arachidonic acid metabolism. In A431 cells, activation of protein kinase C also contributed to ATP-dependent stimulation of uridine uptake. Concentrations of indomethacin and pertussis toxin which inhibited uridine uptake also blocked arachidonic acid metabolism and DNA synthesis. ATP acted as a competence factor. Interestingly, ATP did not have to be continuously present to stimulate uridine uptake. It was equally effective even when it was washed away after brief treatment of cells.
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Affiliation(s)
- N N Huang
- Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853
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12
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Rivedal E, Roseng LE, Sanner T. Vanadium compounds promote the induction of morphological transformation of hamster embryo cells with no effect on gap junctional cell communication. Cell Biol Toxicol 1990; 6:303-14. [PMID: 2253055 DOI: 10.1007/bf02443805] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Vanadium compounds were found to promote the induction of morphological transformation of hamster embryo cells. Exposure of the cells to Na-O-vanadate, vanadin (V) oxide or vanadin (IV) oxide sulfate following pre-exposure to a low concentration of benzo[a]pyrene, potentiated the induction of transformed colonies similar to 12-O-tetradecanoylphorbol-13-acetate. Unlike this phorbol ester, vanadium compounds did not inhibit intercellular communication, or active protein kinase C. Nor did vanadate influence the reoccurrence of communication after removal of a communication blocking phorbol ester. On the other hand, vanadate showed strong synergism with the phorbol ester on induction of transformed morphology in the phorbol ester sensitive cell line BPNi. This suggests that vanadium and tumor promoting phorbol esters mediate their effect on the induction of morphological transformation of hamster embryo cells through different mechanisms.
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Affiliation(s)
- E Rivedal
- Laboratory for Environmental and Occupational Cancer, Norwegian Radium Hospital, Oslo
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13
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Maly K, Hochleitner BW, Grunicke H. Interrelationship between growth factor-induced activation of the Na+/H(+)-antiporter and mobilization of intracellular Ca2+ in NIH3T3-fibroblasts. Biochem Biophys Res Commun 1990; 167:1206-13. [PMID: 2157427 DOI: 10.1016/0006-291x(90)90652-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Addition of serum growth factors or bombesin to quiescent NIH3T3-fibroblasts leads to a simultaneous mobilization of intracellular Ca2+ and an increase in cytosolic pH which is inhibitable by dimethylamiloride. The mobilization of intracellular Ca2+ is a pH-dependent process with an optimum at pH 7.1. In quiescent cells with a pHi greater than or equal to 6.8, inhibition of the Na+/H(+)-antiporter by dimethylamiloride or reduction of extracellular Na+ attenuates the growth factor induced Ca2(+)-response. It is concluded that the growth factor induced activation of the Na+/H(+)-antiporter facilitates the mobilization of Ca2+ by shifting the internal pH towards the optimum for the Ca2(+)-release.
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Affiliation(s)
- K Maly
- Institute for Medical Chemistry and Biochemistry, University of Innsbruck, Austria
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14
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Maly K, Hochleitner B, Uberall F, Loferer H, Oberhuber H, Doppler W, Grunicke H. Mechanism and biological significance of the Ha-ras-induced activation of the Na+/H(+)-antiporter. ADVANCES IN ENZYME REGULATION 1990; 30:63-74. [PMID: 2169700 DOI: 10.1016/0065-2571(90)90009-q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Expression of the transforming Ha-ras oncogene in MMTV-LTR transfected NIH 3T3 cells leads to a growth factor independent activation of the Na+/H(+)-antiporter. The activation of the antiporter is insensitive to the protein kinase inhibitor staurosporine and equally expressed in protein kinase C-depleted cells. It is concluded that the Ha-ras induced activation of the antiporter occurs by a protein kinase C-independent mechanism. An inhibition of the Na+/H(+)-antiporter by dimethylamiloride or a reduction of the extracellular [Na+] concentration results in a depression of the bombesin induced release of Ca2+ from intracellular stores. These results are explained by a steep pH-dependence of the Ca2(+)-mobilizing system which exhibits a maximum at pH 7.1 in the system studied here. Stimulation by growth factors of quiescent cells with a resting pH below 7 results in a shift of the cytosolic pH towards the optimum for the Ca2+ release. In agreement with the proposed interrelationship, pHi and [Ca2+]i rise and peak simultaneously after addition of bombesin to G0 arrested cells.
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Affiliation(s)
- K Maly
- Institute for Medical Chemistry and Biochemistry, University of Innsbruck, Austria
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15
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Grinstein S, Rotin D, Mason MJ. Na+/H+ exchange and growth factor-induced cytosolic pH changes. Role in cellular proliferation. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 988:73-97. [PMID: 2535787 DOI: 10.1016/0304-4157(89)90004-x] [Citation(s) in RCA: 547] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- S Grinstein
- Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
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16
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Frelin C, Vigne P, Ladoux A, Lazdunski M. The regulation of the intracellular pH in cells from vertebrates. EUROPEAN JOURNAL OF BIOCHEMISTRY 1988; 174:3-14. [PMID: 2836200 DOI: 10.1111/j.1432-1033.1988.tb14055.x] [Citation(s) in RCA: 257] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Eukaryotic cells control their intracellular pH using ion-transporting systems that are situated in the plasma membrane. This paper describes the different mechanisms that are involved and how their activity is regulated.
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Affiliation(s)
- C Frelin
- Centre de Biochimie, Centre National de la Recherche Scientifique, Nice, France
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17
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Shechter Y, Meyerovitch J, Amir S. The use of post-binding agents in studying insulin action and its relation to experimental diabetes. Biochem Pharmacol 1988; 37:1891-6. [PMID: 2837217 DOI: 10.1016/0006-2952(88)90533-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This review includes data related to two substances that modulate insulin mechanisms, both in vitro and in the whole animal model. It seems to us that these agents (vanadate and PMXB) will be of potential use in the next decade for basic and applied research. They may assist in characterizing the essential post-binding events involved in insulin action, which cannot presently be identified. As vanadate and PMXB modulate the effects of insulin both in vivo and in vitro, they may be of use in clinical and pathophysiological research as well. VO3- is a low molecular weight substance which permeates the intestinal tract and mimics the actions of insulin in target tissues. Studies that were summarized here may even suggest that VO3- is superior to insulin in stimulating its effects in tissues that are down-regulated or desensitized to the hormone itself. Both VO3- and PMXB may be useful in the treatment of diabetes in the future if long-range toxicity studies prove these agents to be clinically safe. PMXB has already been in use in medicine for several decades now.
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Affiliation(s)
- Y Shechter
- Department of Hormone Research, Weizmann Institute of Science, Rehovot, Israel
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18
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Berchuck A, MacDonald PC, Milewich L, Casey ML. Epidermal growth factor, vanadate, and 12-O-tetradecanoylphorbol-13-acetate inhibit growth and stimulate prostaglandin E2 production in A431 cells. Mol Cell Endocrinol 1988; 57:87-92. [PMID: 3260877 DOI: 10.1016/0303-7207(88)90036-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The cell line designated as A431 is characterized by an extraordinary capacity for binding of epidermal growth factor (EGF); but paradoxically, these cells also are characterized by failure of replication in response to treatment with EGF and other mitogens. In this study, we took advantage of this unique response of A431 cells to EGF and other mitogenic agents. Specifically, we investigated the dependency of mitogen-stimulated prostaglandin production on mitogenesis. The effects of treatment of A431 cells with epidermal growth factor and two other mitogenic agents, viz., sodium orthovanadate and 12-O-tetradecanoylphorbol-13-acetate (TPA), on DNA synthesis and prostaglandin production were evaluated. The rate of prostaglandin production in A431 cells that were treated with each of these agents increased in a manner that was dependent upon the duration of treatment and the concentration of the agent tested. Thus, by use of A431 cells, we find that the effects of 'mitogenic' agents on cell replication and prostaglandin production are clearly dissociable.
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Affiliation(s)
- A Berchuck
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical School, Dallas 75235
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19
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Montesano R, Pepper MS, Belin D, Vassalli JD, Orci L. Induction of angiogenesis in vitro by vanadate, an inhibitor of phosphotyrosine phosphatases. J Cell Physiol 1988; 134:460-6. [PMID: 2450879 DOI: 10.1002/jcp.1041340318] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have previously shown that capillary endothelial cells grown on the surface of three-dimensional collagen gels can be induced to invade the underlying fibrillar matrix and to form capillary-like tubular structures in response to tumor-promoting phorbol esters or the angiogenic agent fibroblast growth factor (FGF). Since both phorbol esters and FGF stimulate phosphorylation of tyrosine residues, we treated endothelial cells with vanadate, an inhibitor of phosphotyrosine-specific phosphatases, to determine whether this agent could induce the expression of an angiogenic phenotype in these cells. We show here that vanadate stimulates endothelial cells to invade collagen matrices and to organize into characteristic tubules resembling those induced by FGF or phorbol esters. We have further observed that vanadate concomitantly stimulates endothelial cells to produce plasminogen activators (PAs), proteolytic enzymes which are induced by phorbol esters and FGF, and which have been implicated in the neovascular response; this stimulation can be accounted for by an increase in the levels of urokinase-type PA and tissue type PA mRNA. These results suggest a role for tyrosine phosphorylation in the regulation of the angiogenic phenotype in capillary endothelial cells.
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Affiliation(s)
- R Montesano
- Institute of Histology and Embryology, University of Geneva Medical Center, Switzerland
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20
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Jamieson GA, Etscheid BG, Muldoon LL, Villereal ML. Effects of phorbol ester on mitogen and orthovanadate stimulated responses of cultured human fibroblasts. J Cell Physiol 1988; 134:220-8. [PMID: 3346337 DOI: 10.1002/jcp.1041340207] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mitogenic stimulation of quiescent human fibroblasts (HSWP) with serum or a mixture of growth factors (consisting of vasopressin, bradykinin, EGF, and insulin) stimulates the release of inositol phosphates, mobilization of intracellular Ca, activation of Na/H exchange and subsequent incorporation of [3H]-thymidine. We have determined previously that pretreatment with the tumor-promoting phorbol ester 12-0-tetradecanoyl-phorbol-13-acetate (TPA) inhibits mitogen-stimulated Na influx in HSWP cells. We report herein that TPA pretreatment also substantially inhibits the mitogen-stimulated release of inositol phosphates in HSWP cells. Half maximal inhibition of mitogen-stimulated inositol phosphate release occurs at 1-2 nM TPA. Treatment of cells with TPA alone has no effect on inositol phosphate release. The effect of TPA pretreatment on inositol phosphate release induced by individual growth factors has also been determined. Orthovanadate, reported by Cassel et al. (1984) to increase Na/H exchange in A431 cells, has been demonstrated to stimulate both Na influx and inositol phosphate release in HSWP cells. TPA pretreatment also inhibits both orthovanadate-stimulated inositol phosphate release and Na influx. In addition, orthovanadate was determined to increase intracellular Ca activity by mobilizing intracellular calcium stores, as determined with the fluorescent intracellular calcium probe fura-2. TPA pretreatment blocks orthovanadate stimulated mobilization of intracellular Ca stores. It appears clear that in HSWP cells pretreatment of cells with phorbol ester is capable of artificially desensitizing the early cellular responses to mitogenic stimuli (growth factors, orthovanadate) by blocking the signal transduction mechanism involved at a point prior to the release of inositol phosphates. We hypothesize that in HSWP cells the normal desensitization of both inositol phosphate release and Na/H exchange is mediated via activation of protein kinase C subsequent to the stimulus-mediated activation of phospholipase C and release of protein kinase C activator diacylglycerol. However it is interesting to note that TPA-mediated inhibition of these early responses in HSWP cells does not inhibit their ability to be stimulated to incorporate [3H]-thymidine.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- G A Jamieson
- Department of Pharmacological and Physiological Sciences, University of Chicago, Illinois 60637
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21
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Grinstein S, Smith JD, Rowatt C, Dixon SJ. Mechanism of activation of lymphocyte Na+/H+ exchange by concanavalin A. A calcium- and protein kinase C-independent pathway. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)48171-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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22
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Abstract
Several ion fluxes are stimulated when mitogenic polypeptides are added to cells. The precise mechanism by which this activation takes place is not understood, but compelling evidence exists in the case of the activation of sodium-hydrogen exchange that it requires the tyrosine kinase activity associated with the mitogen receptor. The activation of sodium-hydrogen exchange by mitogens is associated with changes in intracellular pH that appear to be permissive but not causal in allowing cells to proceed through the cell cycle. When added to cells, mitogens also activate protein kinase C, which acts as part of a feedback loop to control the activity of the mitogen receptor. Possible mechanisms for this control are discussed.
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Affiliation(s)
- L Glaser
- Department of Biological Chemistry, Washington University School of Medicine, St. Louis, Missouri
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23
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Huang CL, Cogan MG, Cragoe EJ, Ives HE. Thrombin activation of the Na+/H+ exchanger in vascular smooth muscle cells. Evidence for a kinase C-independent pathway which is Ca2+-dependent and pertussis toxin-sensitive. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47914-8] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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24
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Donowitz M. Small intestinal and colonic linked sodium chloride absorption. New understanding of distribution and regulation. Gastroenterology 1987; 93:640-3. [PMID: 3609668 DOI: 10.1016/0016-5085(87)90927-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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25
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Macara IG, Gray GM. Vanadate-activated calcium influx in A431 cells is dependent on the plasma membrane potential. J Cell Biochem 1987; 34:125-8. [PMID: 3496344 DOI: 10.1002/jcb.240340206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Vanadate can activate the uptake of Ca in A431 epidermal carcinoma cells by two- to fivefold with no detectable lag period. Preincubation with epidermal growth factor (EGF) to down-regulate the EGF receptor prevents subsequent stimulation by EGF but not that by vanadate. Ca uptake is sodium-independent and is not activated by depolarization in high KCl. On the contrary, vanadate-stimulated uptake is completely inhibited by decreasing the plasma membrane potential from about -65 to -30 mV. These results demonstrate that the EGF receptor is not itself functioning as a Ca channel, that vanadate is not acting at the level of EGF receptor, and that the Ca transport system exhibits an unusual potential sensitivity in that it is inhibited by depolarization of the plasma membrane.
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JAMIESON GORDONA, VILLEREAL MITCHELL. Stimulation of Inositol Phosphate Release in Intact and Permeabilized Fibroblasts. Ann N Y Acad Sci 1987. [DOI: 10.1111/j.1749-6632.1987.tb29499.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ives HE, Daniel TO. Interrelationship between growth factor-induced pH changes and intracellular Ca2+. Proc Natl Acad Sci U S A 1987; 84:1950-4. [PMID: 3470769 PMCID: PMC304559 DOI: 10.1073/pnas.84.7.1950] [Citation(s) in RCA: 103] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Many mitogens cause rapid changes in intracellular pH and Ca2+. We studied the patterns of pH and Ca2+ changes after exposure of murine fibroblasts to platelet-derived growth factor (PDGF), bombesin, phorbol 12-myristate 13-acetate (PMA), and the vasoactive peptide bradykinin. Intracellular pH and Ca2+ were measured by using the fluorescent dyes 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein and fura-2. Three distinct patterns of intracellular pH change were observed. PDGF and bombesin caused a rapid (maximum change, less than 2 min) cytoplasmic acidification of 0.03 pH unit followed by a slower (5-10 min) alkalinization of approximately 0.11 pH unit above the resting pH of 6.88. PMA caused alkalinization without causing the early acidification. Bradykinin caused rapid acidification without the slower net alkalinization. Ionomycin also caused acidification without subsequent alkalinization. All acidification responses were amiloride resistant. Patterns of intracellular Ca2+ response were also determined for each agent. PDGF and bombesin caused a transient increase in cytoplasmic Ca2+ from a resting level of 85 +/- 12 nM to 190 +/- 12 nM within 2 min and return to baseline within 5 min. PMA caused no change in intracellular Ca2+. Bradykinin caused the most rapid (maximum response, less than 20 sec) increase in intracellular Ca2+. For each agonist, the Ca2+ transient could be blocked by buffering intracellular Ca2+ with quin-2. In Ca2+-buffered cells, PDGF, bombesin, bradykinin, and ionomycin failed to induce cellular acidification, but alkalinization responses to PDGF, bombesin, and PMA persisted. We propose that the transient acidification seen with PDGF, bombesin, and other agents is the result of increased intracellular Ca2+. However, growth factor-induced alkalinization via the Na+/H+ exchanger is independent of changes in Ca2+.
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Paris S, Chambard J, Pouysségur J. Coupling between phosphoinositide breakdown and early mitogenic events in fibroblasts. Studies with fluoroaluminate, vanadate, and pertussis toxin. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61607-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Wice B, Milbrandt J, Glaser L. Control of muscle differentiation in BC3H1 cells by fibroblast growth factor and vanadate. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(19)75711-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Muldoon LL, Jamieson GA, Villereal ML. Calcium mobilization in permeabilized fibroblasts: effects of inositol trisphosphate, orthovanadate, mitogens, phorbol ester, and guanosine triphosphate. J Cell Physiol 1987; 130:29-36. [PMID: 3492499 DOI: 10.1002/jcp.1041300106] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Utilizing a digitonin-permeabilized cell system, we have studied the release of calcium from a non-mitochondrial intracellular compartment in cultured human fibroblasts (HSWP cells). Addition of 1 mM MgATP to a monolayer of permeabilized cells in a cytosolic media buffered to 150 nM Ca with EGTA rapidly stimulates 45Ca uptake, and the subsequent addition of the putative intracellular messenger inositol trisphosphate (InsP3) induces rapid release of 85% (+/- 6% n = 6) of the 45Ca taken up in response to ATP. Mitogenic peptides (bradykinin, vasopressin, epidermal growth factor [EGF], and insulin) and orthovanadate, which are effective in mobilizing intracellular Ca in intact cells, have little or no effect when added alone to permeabilized cells. However, in the presence of GTP these agents stimulate accumulation of inositol phosphates and release Ca from the InsP3-sensitive pool. These data suggest that a GTP binding protein is involved in receptor mediated activation of phospholipase C, which leads to release of inositol phosphates. The GTP-dependent release of InsP3 and the mobilization of 45Ca from the intracellular compartment are inhibited by pretreatment of cells, prior to permeabilization, with the protein kinase C activator 12-O-tetradecanoyl-phorbol-13-acetate (TPA). TPA pretreatment does not affect the InsP3 stimulated Ca release. These results suggest that protein kinase C is involved in down-regulation or inhibition of phospholipase C, or the GTP binding protein responsible for relaying the mitogenic signal from the cell surface receptor to the phospholipase C activity.
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Lahav M, Rennert H, Barzilai D. Inhibition by vanadate of cyclic AMP production in rat corpora lutea incubated in vitro. Life Sci 1986; 39:2557-64. [PMID: 2432373 DOI: 10.1016/0024-3205(86)90109-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Vanadate, a normal constituent of cells, has been reported to affect a variety of enzymes involved in phosphate transfer; the findings regarding adenylate cycle vary with the tissue and experimental system. In the corpus luteum, cyclic AMP (cAMP) stimulates steroidogenesis; and prostaglandin F2 alpha, which induces luteal regression, inhibits luteinizing hormone (LH)-induced cAMP accumulation. We examined the influence of orthovanadate on cAMP concentration in isolated corpora lutea from pseudopregnant rats. With 2 mM vanadate, basal cAMP level was unaffected, but LH-induced cAMP accumulation was inhibited by 45-68%. Lower doses of vanadate (0.2-1 mM) were almost as effective. When added simultaneously with LH, vanadate was inhibitory within 25 min, but no inhibition occurred when vanadate was added for 30 min to tissue pretreated with LH for 60 min. The decrease in cAMP accumulation was observed also when corpora lutea were exposed to vanadate in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.5 mM), indicating that vanadate inhibits cAMP synthesis. Vanadate may increase cytosolic calcium by inhibiting ion pumps in cell membranes. Thus, we examined the effect of vanadate in corpora lutea incubated in calcium-depleted medium and found that vanadate still inhibited cAMP formation. Vanadyl sulfate (0.4 and 2 mM) reduced the LH-induced cAMP accumulation as effectively as vanadate. Thus, the use of vanadate as a tool for exploring physiological regulators of luteal adenylate cyclase should be considered.
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Activation of 45Ca2+ influx and 22Na+/H+ exchange by epidermal growth factor and vanadate in A431 cells is independent of phosphatidylinositol turnover and is inhibited by phorbol ester and diacylglycerol. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)67657-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Olsnes S, Carvajal E, Sandvig K. Interactions between diphtheria toxin entry and anion transport in vero cells. III. Effect on toxin binding and anion transport of tumor-promoting phorbol esters, vanadate, fluoride, and salicylate. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(17)35976-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Chapter 1 Mitogens and Ion Fluxes. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/s0070-2161(08)60352-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Grinstein S, Goetz JD, Cohen S, Rothstein A, Gelfand EW. Regulation of Na+/H+ exchange in lymphocytes. Ann N Y Acad Sci 1985; 456:207-19. [PMID: 3004288 DOI: 10.1111/j.1749-6632.1985.tb14866.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Crane FL, Sun IL, Clark MG, Grebing C, Löw H. Transplasma-membrane redox systems in growth and development. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 811:233-64. [PMID: 3893544 DOI: 10.1016/0304-4173(85)90013-8] [Citation(s) in RCA: 388] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Mancuso D, Glaser L. Characterization of the Na+/H+ exchanger in human epidermoid carcinoma A431 vesicles. J Cell Physiol 1985; 123:297-304. [PMID: 3988809 DOI: 10.1002/jcp.1041230302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A previous report from this laboratory (Rothenberg et al., 1983a) demonstrated the presence of an Na+/H+ exchanger in human epidermoid carcinoma A431 cells. We now characterize surface-derived membrane vesicles from this cell line which contain a functional Na+/H+ exchanger. The Na+/H+ exchanger in A431 vesicles shares a number of characteristics in common with previously described Na+/H+ exchangers including the following: (1) Na+ uptake is stimulated by an outward-directed pH gradient and inhibited by an inward-directed pH gradient. (2) Na+ uptake is inhibited by amiloride and its analogs and their relative effectiveness is similar in vesicles and A431 cells. (3) The Na+/H+ exchanger uses Na+ or Li+ as a substrate but not K+ or Cs+. (4) H+ efflux is stimulated by an inward-directed Na+ gradient and inhibited by the amiloride analog 5-N-dimethylamiloride. The Na+/H+ exchanger in these membrane vesicles is activated allosterically by low intravesicular pH. The apparent pKa of the activating site is 6.4-6.6, characteristic of the NA+/H+ exchanger before activation by mitogens.
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Characterization of the activation of Na+/H+ exchange in lymphocytes by phorbol esters: change in cytoplasmic pH dependence of the antiport. Proc Natl Acad Sci U S A 1985; 82:1429-33. [PMID: 2983345 PMCID: PMC397275 DOI: 10.1073/pnas.82.5.1429] [Citation(s) in RCA: 196] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Phorbol 12-myristate 13-acetate and other phorbol esters induce an intracellular alkalinization in rat thymic lymphocytes. An extracellular acidification can be recorded concomitantly. This transmembrane H+ (equivalent) flux is dependent on external Na+ and is amiloride sensitive. Phorbol esters also stimulate an amiloride-sensitive uptake of 22Na+, suggesting activation of Na+o/H+i exchange. Only those phorbol derivatives that are tumor promoters and activators of protein kinase C stimulate the antiport. Activation of the Na+/H+ exchange is brought about by a change in the cytoplasmic pH sensitivity of the antiport. Activation of the Na+/H+ exchanger by phorbol esters results in membrane hyperpolarization, due to indirect stimulation of the electrogenic Na+/K+ pump by the increased intracellular Na+ concentration. Increased Na+/H+ exchange also produces cell swelling, which may be one of the earliest manifestations of the growth-promoting properties of the phorbol esters.
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Cassel D, Whiteley B, Zhuang YX, Glaser L. Mitogen-independent activation of Na+/H+ exchange in human epidermoid carcinoma A431 cells: regulation by medium osmolarity. J Cell Physiol 1985; 122:178-86. [PMID: 3918045 DOI: 10.1002/jcp.1041220203] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Previous studies have documented the activation of Na+/H+ exchange in A431 cells by the addition of epidermal growth factor or serum (Rothenberg et al., 1983b). Here we show that exposure of A4 31 cells to medium of increased osmolarity also leads to activation of Na+/H+ exchange and to an increase in intracellular pH (pHi), which under a variety of conditions displays similar kinetics to that observed upon addition of mitogens to the cells. Measurements of cell volume using the 3-0-methylglucose equilibration technique clearly show that mitogens do not activate Na+/H+ exchange by an osmotic mechanism (i.e., a decrease in cell volume). In fact, mitogens can induce further intracellular alkalinization if added to cells which have been shrunken in hypertonic medium. Activation of the Na+/H+ antiport does not lead to an obligatory change in pHi. Addition of epidermal growth factor of hypertonic solution to A431 cells in bicarbonate buffer activates Na+/H+ exchange without a concomitant increase in pHi. Under these conditions the increased proton efflux via Na+/H+ exchange must therefore be compensated by other mechanisms that control cytoplasmic pH.
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Whiteley B, Cassel D, Zhuang YX, 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; 99:1162-6. [PMID: 6088556 PMCID: PMC2113392 DOI: 10.1083/jcb.99.3.1162] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Addition of polypeptide growth factors to cultured cells results in a rapid stimulation of Na+/H+ exchange, which leads to cytoplasmic alkalinization. We studied the effects of the potent tumor promoter phorbol 12-myristate 13-acetate (PMA) on the Na+/H+ exchange system of A431 cells. Stimulation of Na+/H+ exchange by epidermal growth factor (EGF) and serum as well as by vanadate ions is strongly inhibited after treatment of cells with nanomolar concentrations of PMA. Phorbol esters that have no activity as tumor promoters also do not modulate the activation of Na+/H+ exchange. By contrast, the stimulation of Na+/H+ exchange that is produced upon exposure of cells to hypertonic solution is only slightly inhibited by PMA treatment, indicating that PMA treatment does not directly block the activity of the Na+/H+ antiporter. Furthermore, incubation of cells with PMA causes a weak stimulation of Na+/H+ exchange, although this effect is mostly observed at relatively high PMA concentrations and appears to require external Ca2+. The inhibition BY PMA of EGF-promoted Na+/H+ exchange is not due to inhibition of EGF-binding to the EGF receptor. Since PMA activates protein kinase C, our observations are consistent with the hypothesis that protein kinase C functions to attenuate the stimulation of Na+/H+ exchange by polypeptide growth factors.
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Glaser L, Whiteley B, Rothenberg P, Cassel D. Mitogenic polypeptides control ion flux in responsive cells. Bioessays 1984. [DOI: 10.1002/bies.950010108] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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