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Ouabain binding kinetics and FXYD7 expression in astrocytes and neurons in primary cultures: implications for cellular contributions to extracellular K+ homeostasis?

Published online by Cambridge University Press:  26 February 2010

Liang Peng
Affiliation:
Department of Clinical Pharmacology, China Medical University, Shenyang, P.R. China
Rong Huang
Affiliation:
Department of Pharmacology, School of Medicine, University of Saskatchewan, Saskatoon, Canada
Shiquen Zhang
Affiliation:
Department of Clinical Pharmacology, China Medical University, Shenyang, P.R. China
Leif Hertz*
Affiliation:
Department of Clinical Pharmacology, China Medical University, Shenyang, P.R. China Department of Pharmacology, School of Medicine, University of Saskatchewan, Saskatoon, Canada
*
Correspondence should be addressed to: Leif Hertz, R.R. 2, Box 245 (538 Skene Road) Gilmour, ON K0L 1W0Canada phone: 1 613 474 0537 fax: 1 613 474 0538 email: leifhertz@xplornet.ca

Abstract

Although Na+,K+-ATPase-mediated K+ uptake into astrocytes plays a major role in re-establishing resting extracellular K+ following neuronal excitation little information is available about astrocytic Na+,K+-ATPase function, let alone mechanisms returning K+ to neurons. The catalytic units of the Na+,K+-ATPase are the astrocyte-specific α2, the neuron-specific α3 and the ubiquitously expressed α1. In the present work, Bmax and KD values for α1, α2 and α3 subunits were computed in cultured cerebro-cortical mouse astrocytes and cerebellar granule neurons by non-linear regression as high-affinity (α2, α3) and low-affinity (α1) [3H]ouabain binding sites, which stoichiometrically equal transporter sites. Cellular expression was also determined of the brain- and α11 isoform-specific FDYX7, regulating Na+,K+-ATPase efficiency and K+-sensitivity. From ouabain-sensitive K+ uptake rates published by ourselves (Walz and Hertz, 1982) or others (Atterwill et al., 1985), Na+,K+-ATPase turnover was determined. Subunits α2 and α3 showed Bmax of 15–30 pmol/mg protein, with maximum turnover rates of 70–80/s. Bmax of the α1 subunit was low in neurons but very high in astrocytes (645 pmol/mg protein), where turnover rate was slow, reflecting expression of selectively expressed FXYD7, and binding was increased by K+. The role of these characteristics for K+ homeostasis are discussed.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2010

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References

REFERENCES

Atterwill, C.K., Cunningham, V.J. and Balázs, R. (1984) Characterization of Na+,K+-ATPase in cultured and separated neuronal and glial cells from rat cerebellum. Journal of Neurochemistry 43, 818.CrossRefGoogle ScholarPubMed
Atterwill, C.K., Atkinson, D.J., Bermudez, I. and Balázs, R. (1985) Effect of thyroid hormone and serum on the development of Na+,K+-Adenosine triphosphatase and associated ion fluxes in cultures from rat brain. Neuroscience 14, 361375.CrossRefGoogle ScholarPubMed
Bagrov, A.Y., Shapiro, J.I. and Fedorova, O.V. (2009) Endogenous cardiotonic steroids: physiology, pharmacology, and novel therapeutic targets. Pharmacological Reviews 61, 938.CrossRefGoogle ScholarPubMed
Béguin, P., Crambert, G., Monnet-Tschudi, F., Uldry, M., Horisberger, J.D., Garty, H. et al. (2002) FXYD7 is a brain-specific regulator of Na,K-ATPase alpha 1-beta isozymes. EMBO Journal 21, 32643273.CrossRefGoogle ScholarPubMed
Bignami, A. and Palladini, G. (1966) Experimentally produced cerebral status spongiosus and continuous pseudorhythmic electroencephalographic discharges with a membrane-ATPase inhibitor in the rat. Nature 209, 413414.CrossRefGoogle ScholarPubMed
Blanco, G. and Mercer, R.W. (1998) Isozymes of the Na-K-ATPase: heterogeneity in structure, diversity in function. American Journal of Physiology 275, F633F650.Google ScholarPubMed
Cahoy, J.D., Emery, B., Kaushal, A., Foo, L.C., Zamanian, J.L., Christopherson, K.S. et al. (2008) A transcription database for astrocytes, neurons, and oligodendrocytes: a new resource for understanding brain development and function. Journal of Neuroscience 28, 264278.CrossRefGoogle Scholar
Chen, Y., McNeill, J.R., Hajek, I. and Hertz, L. (1992) Effect of vasopressin on brain swelling at the cellular level: do astrocytes exhibit a furosemide – vasopressin-sensitive mechanism for volume regulation? Canadian Journal of Physiology and Pharmacology 70(Supplementum), S367S373.CrossRefGoogle ScholarPubMed
Clausen, T. (2003) Na+-K+ pump regulation and skeletal muscle contractility. Physiological Reviews 83, 12691324.CrossRefGoogle ScholarPubMed
Clausen, T., Everts, M.E. and Kjeldsen, K. (1987) Quantification of the maximum capacity for active sodium-potassium transport in rat skeletal muscle. Journal of Physiology 388, 163181.CrossRefGoogle ScholarPubMed
Cornog, J.L., Gonatas, N.K. and Feierman, J.R. (1967) Effects of intracerebral injection of ouabain on the fine structure of rat cerebral cortex. American Journal of Pathology 51, 573590.Google ScholarPubMed
Crambert, G., Hasler, U., Beggah, A.T., Yu, C., Modyanov, N.N., Horisberger, J.D. et al. (2000) Transport and pharmacological properties of nine different human Na, K-ATPase isozymes. Journal of Biological Chemistry 275, 19761986.CrossRefGoogle ScholarPubMed
el-Marjou, A., Delouvée, A., Thiery, J.P. and Radvanyi, F. (2000) Involvement of epidermal growth factor receptor in chemically induced mouse bladder tumour progression. Carcinogenesis 21, 22112218.CrossRefGoogle ScholarPubMed
Fedorova, O.V., Kolodkin, N.I., Agalakova, N.I., Lakatta, E.G. and Bagrov, A.Y. (2001) Marinobufagenin, an endogenous alpha-1 sodium pump ligand, in hypertensive Dahl salt-sensitive rats. Hypertension 37, 462466.CrossRefGoogle ScholarPubMed
Fedorova, O.V., Zhuravin, I.A., Agalakova, N.I., Yamova, L.A., Talan, M.I., Lakatta, E.G. et al. (2007) Intrahippocampal microinjection of an exquisitely low dose of ouabain mimics NaCl loading and stimulates a bufadienolide Na/K-ATPase inhibitor. Journal of Hypertension 25, 18341844.CrossRefGoogle ScholarPubMed
Gallo, V., Kingsbury, A., Balázs, R. and Jørgensen, O.S. (1987) The role of depolarization in the survival and differentiation of cerebellar granule cells in culture. Journal of Neuroscience 7, 22032213.CrossRefGoogle ScholarPubMed
Garcia-Rudaz, C., Deng, V., Matagne, V., Ronnekleiv, O.K., Bosch, M., Han, V. et al. (2009) FXYD1, a modulator of Na,K-ATPase activity, facilitates female sexual development by maintaining gonadotrophin-releasing hormone neuronal excitability. Journal of Neuroendocrinology 21, 108122.CrossRefGoogle ScholarPubMed
Gardner, J.D. and Conlon, T.P. (1972) The effects of sodium and potassium on ouabain binding by human erythrocytes. Journal of General Physiology 60, 609629.CrossRefGoogle ScholarPubMed
Golovina, V.A., Song, H., James, P.F., Lingrel, J.B. and Blaustein, M.P. (2003) Na+ pump alpha 2-subunit expression modulates Ca2+ signaling. American Journal of Physiology, Cell Physiology 284, C475C486.CrossRefGoogle ScholarPubMed
Grisar, T., Frère, J.M. and Franck, G. (1979) Effect of K+ ions on kinetic properties of the Na+, K+-ATPase (EC 3.6.1.3) of bulk isolated glial cells, perikarya and synaptosomes from rabbit brain cortex. Brain Research 165, 87103.CrossRefGoogle Scholar
Hajek, I., Subbarao, K.V. and Hertz, L. (1996) Stimulation of Na+,K+-ATPase activity in astrocytes and neurons by K+ and/or noradrenaline. Neurochemistry International 28, 335342.CrossRefGoogle ScholarPubMed
Henn, F.A., Haljamäe, H. and Hamberger, A. (1972) Glial cell function: active control of extracellular K+ concentration. Brain Research 43, 437443.CrossRefGoogle ScholarPubMed
Hertz, L. (1979) Inhibition by barbiturates of an intense net uptake of potassium into astrocytes. Neuropharmacology 18, 629633.CrossRefGoogle ScholarPubMed
Hertz, L. (2008) Bioenergetics of cerebral ischemia: a cellular perspective. Neuropharmacology 55, 289309.CrossRefGoogle ScholarPubMed
Hertz, L., Juurlink, B.H.J., Fosmark, H. and Schousboe, A. (1982) Astrocytes in primary cultures. In Pfeiffer, S.E. (ed) Neuroscience Approached Through Cell Culture, vol. 1. Boca Raton, FL: CRC Press, pp 175186.Google Scholar
Hertz, L., Peng, L. and Lai, J.C.K. (1998) Functional studies in cultured astrocytes. Methods – A Companion to Methods in Enzymology 16, 293310.CrossRefGoogle ScholarPubMed
Hertz, L., Peng, L. and Dienel, G.A. (2007) Energy metabolism in astrocytes: high rate of oxidative metabolism and spatiotemporal dependence on glycolysis/glycogenolysis. Journal of Cerebral Blood Flow and Metabolism 27, 219249.CrossRefGoogle ScholarPubMed
Juhaszova, M. and Blaustein, MP. (1997) Na+ pump low and high ouabain affinity alpha subunit isoforms are differently distributed in cells. Proceedings of the National Academy of Sciences of the U.S.A. 94, 18001805.CrossRefGoogle ScholarPubMed
Kala, G., Kumarathasan, R., Peng, L., Leenen, F.H. and Hertz, L. (2000) Stimulation of Na+,K+-ATPase activity, increase in potassium uptake, and enhanced production of ouabain-like compounds in ammonia-treated mouse astrocytes. Neurochemistry International 36, 203211.CrossRefGoogle ScholarPubMed
Kong, E.K., Peng, L., Chen, Y., Yu, A.C.H. and Hertz, L. (2002) Up-regulation of 5-HT2B receptor density and receptor-mediated glycogenolysis in mouse astrocytes by long-term fluoxetine administration. Neurochemical Research 27, 113120.CrossRefGoogle ScholarPubMed
Krnjevic, K. and Morris, M.E. (1972) Extracellular K+ activity and slow potential changes in spinal cord and medulla. Canadian Journal of Physiology and Pharmacology 50, 12141217.CrossRefGoogle ScholarPubMed
Landowne, D. and Ritchie, J.M. (1970) The binding of tritiated ouabain to mammalian non-myelinated nerve fibres. Journal of Physiology 207, 529537.CrossRefGoogle ScholarPubMed
Lobaugh, L.A. and Lieberman, M. (1987) Na-K pump site density and ouabain binding affinity in cultured chick heart cells. American Journal of Physiology 253, C731C743.CrossRefGoogle ScholarPubMed
Lowry, O.H., Rosebrough, N.J., Farr, A.L. and Randall, R.J. (1951) Protein measurement with the Folin phenol reagent. Journal of Biological Chemistry 193, 265275.CrossRefGoogle ScholarPubMed
Maki, A.A., Baskin, D.G. and Stahl, W.L. (1992) [3H]-ouabain binding sites in rat brain: distribution and properties assessed by quantitative autoradiography. Journal of Histochemistry and Cytochemistry 40, 771779.CrossRefGoogle Scholar
Marks, M.J. and Seeds, N.W. (1978) A heterogeneous ouabain-ATPase interaction in mouse brain. Life Sciences 23, 27352744.CrossRefGoogle ScholarPubMed
Matsuda, T., Murata, Y., Kawamura, N., Hayashi, M., Tamada, K., Takuma, K. et al. (1993) Selective induction of alpha 1 isoform of (Na+ + K+)-ATPase by insulin/insulin-like growth factor-I in cultured rat astrocytes. Archives of Biochemistry and Biophysics 307, 175182.CrossRefGoogle ScholarPubMed
McGrail, K.M., Phillips, J.M. and Sweadner, K.J. (1991) Immunofluorescent localization of three Na,K-ATPase isozymes in the rat central nervous system: both neurons and glia can express more than one Na,K-ATPase. Journal of Neuroscience 11, 381391.CrossRefGoogle ScholarPubMed
Meier, E., Hertz, L. and Schousboe, A. (1991) Neurotransmitters as developmental signals. Neurochemistry International 19, 115.CrossRefGoogle Scholar
Mercado, R. and Hernández, J. (1992) Regulatory role of a neurotransmitter (5-HT) on glial Na+/K+-ATPase in the rat brain. Neurochemistry International 21, 119127.CrossRefGoogle ScholarPubMed
Moonen, G. and Franck, G. (1977) Potassium effect on Na+, K+-ATPase activity of cultured newborn rat astroblasts during differentiation. Neuroscience Letters 4, 263267.CrossRefGoogle ScholarPubMed
Müller-Ehmsen, J., Juvvadi, P., Thompson, C.B., Tumyan, L., Croyle, M., Lingrel, J.B. et al. (2001) Ouabain and substrate affinities of human Na+-K+-ATPase alpha(1)beta(1), alpha(2)beta(1), and alpha(3)beta(1) when expressed separately in yeast cells. American Journal of Physiology, Cell Physiology 281, C1355C1364.CrossRefGoogle Scholar
Noël, F., Fagoo, M. and Godfraind, T. (1990) A comparison of the affinities of rat (Na+ + K+)-ATPase isozymes for cardioactive steroids, role of lactone ring, sugar moiety and KCl concentration. Biochemical Pharmacology 40, 26112616.CrossRefGoogle ScholarPubMed
Peng, L., Juurlink, B.H.J. and Hertz, L. (1991) Differences in transmitter release, morphology, and ischemia-induced cell injury between cerebellar granule cell cultures developing in the presence and in the absence of a depolarizing potassium concentration. Developmental Brain Research 63, 112.CrossRefGoogle ScholarPubMed
Peng, L., Zhang, X. and Hertz, L. (1994) High extracellular potassium concentrations stimulate oxidative metabolism in a glutamatergic neuronal culture and glycolysis in cultured astrocytes but have no stimulatory effect in a GABAergic neuronal culture. Brain Research 663, 168172.CrossRefGoogle Scholar
Peng, L., Martin-Vasallo, P. and Sweadner, K.J. (1997) Isoforms of Na,K-ATPase alpha and beta subunits in the rat cerebellum and in granule cell cultures. Journal of Neuroscience 17, 34883502.CrossRefGoogle ScholarPubMed
Peng, L., Arystarkhova, E. and Sweadner, K.J. (1998) Plasticity of Na,K-ATPase isoform expression in cultures of flat astrocytes: species differences in gene expression. Glia 24, 257271.3.0.CO;2-#>CrossRefGoogle ScholarPubMed
Plesner, I.W. and Plesner, L. (1981) The steady-state kinetic mechanism of ATP hydrolysis catalyzed by membrane-bound (Na+ + K+)-ATPase from ox brain. Biochimica Biophysica Acta 648, 231246.CrossRefGoogle ScholarPubMed
Rose, C.R. and Ransom, B.R. (1996) Intracellular sodium homeostasis in rat hippocampal astrocytes. Journal of Physiology 491, 291305.CrossRefGoogle ScholarPubMed
Schmidt, T.A., Larsen, J.S. and Kjeldsen, K. (1992) Quantification of rat cerebral cortex Na+,K+-ATPase: effect of age and potassium depletion. Journal of Neurochemistry 59, 20942104.CrossRefGoogle ScholarPubMed
Schmidt, T.A., Hasselbalch, S., Larsen, J.S., Bundgaard, H., Juhler, M. and Kjeldsen, K. (1996) Reduction of cerebral cortical [3H]ouabain binding site (Na+,K+-ATPase) density in dementia as evaluated in fresh human cerebral cortical biopsies. Cognitive Brain Research 4, 281287.CrossRefGoogle ScholarPubMed
Schubert, P., Morino, T., Miyazaki, H., Ogata, T., Nakamura, Y., Marchini, C. et al. (2000) Cascading glia reactions: a common pathomechanism and its differentiated control by cyclic nucleotide signaling. Annals of the New York Academy of Sciences 903, 2433.CrossRefGoogle ScholarPubMed
Somjen, G.G., Kager, H. and Wadman, W.J. (2008) Computer simulations of neuron–glia interactions mediated by ion flux. Journal of Computational Neuroscience 25, 349365.CrossRefGoogle ScholarPubMed
Stimers, J.R., Lobaugh, L.A., Liu, S., Shigeto, N. and Lieberman, M. (1990) Intracellular sodium affects ouabain interaction with the Na/K pump in cultured chick cardiac myocytes. Journal of General Physiology 95, 7795.CrossRefGoogle ScholarPubMed
Sweadner, K.J. (1979) Two molecular forms of (Na+ + K+)-stimulated ATPase in brain. Separation, and difference in affinity for strophanthidin. Journal of Biological Chemistry 254, 60606067.CrossRefGoogle Scholar
Sweadner, K.J. and Rael, E. (2000) The FXYD gene family of small ion transport regulators or channels: cDNA sequence, protein signature sequence, and expression. Genomics 68, 4156.CrossRefGoogle ScholarPubMed
Urayama, O. and Nakao, M. (1979) Organ secificity of rat sodium- and potassium-activated adenosine triphosphatase. Journal of Biochemistry 86, 13711381.CrossRefGoogle ScholarPubMed
Vyklický, L., Syková, E., Kriz, N. and Ujec, E. (1972) Post-stimulation changes of extracellular potassium concentrations in the spinal cord of the rat. Brain Research 45, 608612.CrossRefGoogle ScholarPubMed
Walz, W. and Hertz, L. (1982) Ouabain-sensitive and ouabain-resistant net uptake of potassium into astrocytes and neurons in primary cultures. Journal of Neurochemistry 39, 7077.CrossRefGoogle ScholarPubMed
Wandosell, F., Bovolenta, P. and Nieto-Sampedro, M. (1993) Differences between reactive astrocytes and cultured astrocytes treated with di-butyryl-cyclic AMP. Journal of Neuropathology and Experimental Neurolology 52, 205215.CrossRefGoogle ScholarPubMed