Decreased glial and synaptic glutamate uptake in the striatum of HIV-1 gp120 transgenic mice

Abstract

The mechanisms leading to the neurocognitive deficits in humans with immunodeficiency virus type 1 (HIV-1) are not well resolved. A number of cell culture models have demonstrated that the HIV-envelope glycoprotein 120 (gp120) decreases the reuptake of glutamate, which is necessary for learning, memory, and synaptic plasticity. However, the impact of brain HIV-1 gp120 on glutamate uptake systems in vivo remains unknown. Notably, alterations in brain glutamate uptake systems are implicated in a number of neurodegenerative and neurocognitive disorders. We characterized the kinetic properties of system XAG (sodium-dependent) and systems xc- (sodium-independent) [3H]-l-glutamate uptake in the striatum and hippocampus of HIV-1 gp120 transgenic mice, an established model of HIV neuropathology. We determined the kinetic constant Vmax (maximal velocity) and Km (affinity) of both systems XAG and xc- using subcellular preparations derived from neurons and glial cells. We show significant (30–35 %) reductions in the Vmax of systems XAG and xc- in both neuronal and glial preparations derived from the striatum, but not from the hippocampus of gp120 mice relative to wild-type (WT) controls. Moreover, immunoblot analysis showed that the protein expression of glutamate transporter subtype-1 (GLT-1), the predominant brain glutamate transporter, was significantly reduced in the striatum but not in the hippocampus of gp120 mice. These extensive and region-specific deficits of glutamate uptake likely contribute to the development and/or severity of HIV-associated neurocognitive disorders. Understanding the role of striatal glutamate uptake systems in HIV-1 gp120 may advance the development of new therapeutic strategies to prevent neuronal damage and improve cognitive function in HIV patients.

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References

  1. AVMA (2013) AVMA guidelines for the euthanasia of animals, 2013 edn. American Veterinary Medical Association, Schaumburg, IL

  2. Baker DA, Xi ZX, Shen H, Swanson CJ, Kalivas PW (2002) The origin and neuronal function of in vivo nonsynaptic glutamate. J Neurosci 22:9134–9141

    CAS  PubMed  Google Scholar 

  3. Belmadani A, Zou JY, Schipma MJ, Neafsey EJ, Collins MA (2001) Ethanol pre-exposure suppresses HIV-1 glycoprotein 120-induced neuronal degeneration by abrogating endogenous glutamate/Ca2+-mediated neurotoxicity. Neuroscience 104:769–781

    CAS  Article  PubMed  Google Scholar 

  4. Benos DJ, Hahn BH, Bubien JK, Ghosh SK, Mashburn NA, Chaikin MA, Shaw GM, Benveniste EN (1994) Envelope glycoprotein gp120 of human immunodeficiency virus type 1 alters ion transport in astrocytes: implications for AIDS dementia complex. Proc Natl Acad Sci U S A 91:494–498

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  5. Bridges RJ, Natale NR, Patel SA (2012) System xc(−) cystine/glutamate antiporter: an update on molecular pharmacology and roles within the CNS. Br J Pharmacol 165:20–34. doi:10.1111/j.1476-5381.2011.01480

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  6. Cho Y, Bannai S (1990) Uptake of glutamate and cysteine in C-6 glioma cells and in cultured astrocytes. J Neurochem 55:2091–2097

    CAS  Article  PubMed  Google Scholar 

  7. Choi DW (1988) Glutamate neurotoxicity and diseases of the nervous system. Neuron 1:623–634

    CAS  Article  PubMed  Google Scholar 

  8. Danbolt NC (2001) Glutamate uptake. Prog Neurobiol 65:1–105

    CAS  Article  PubMed  Google Scholar 

  9. Dreyer EB, Lipton SA (1995) The coat protein gp120 of HIV-1 inhibits astrocyte uptake of excitatory amino acids via macrophage arachidonic acid. Eur J Neurosci 7:2502–2507

    CAS  Article  PubMed  Google Scholar 

  10. Dunkley PR, Jarvie PE, Robinson PJ (2008) A rapid Percoll gradient procedure for preparation of synaptosomes. Nat Protoc 3:1718–1728. doi:10.1038/nprot.2008.171

    CAS  Article  PubMed  Google Scholar 

  11. Ellis R, Langford D, Masliah E (2007) HIV and antiretroviral therapy in the brain: neuronal injury and repair. Nat Rev Neurosc 8:33–44

    CAS  Article  Google Scholar 

  12. Gonzalez MI, Robinson MB (2004) Neurotransmitter transporters: why dance with so many partners? Curr Opin Pharmacol 4:30–35. doi:10.1016/j.coph.2003.09.004

    CAS  Article  PubMed  Google Scholar 

  13. Hirst WD, Price GW, Rattray M, Wilkin GP (1998) Serotonin transporters in adult rat brain astrocytes revealed by [3H]5-HT uptake into glial plasmalemmal vesicles. Neurochem Int 33:11–12

    CAS  Article  PubMed  Google Scholar 

  14. Holden CP, Haughey NJ, Nath A, Geiger JD (1999) Role of Na+/H+ exchangers, excitatory amino acid receptors and voltage-operated Ca2+ channels in human immunodeficiency virus type 1 gp120-mediated increases in intracellular Ca2+ in human neurons and astrocytes. Neuroscience 91:1369–1378

    CAS  Article  PubMed  Google Scholar 

  15. Huang YH, Bergles DE (2004) Glutamate transporters bring competition to the synapse. Curr Opin Neurobiol 14:346–352. doi:10.1016/j.conb.2004.05.007

    CAS  Article  PubMed  Google Scholar 

  16. Kalivas PW (2009) The glutamate homeostasis hypothesis of addiction. Nat Rev Neurosci 10:561–572. doi:10.1038/nrn2515

    CAS  Article  PubMed  Google Scholar 

  17. Kanai Y, Hediger MA (2003) The glutamate and neutral amino acid transporter family: physiological and pharmacological implications. Eur J Pharmacol 479:237–247

    CAS  Article  PubMed  Google Scholar 

  18. Kaul M, Garden GA, Lipton SA (2001) Pathways to neuronal injury and apoptosis in HIV-associated dementia. Nature 410:988–994. doi:10.1038/35073667

    CAS  Article  PubMed  Google Scholar 

  19. Matsugami TR, Tanemura K, Mieda M, Nakatomi R, Yamada K, Kondo T, Ogawa M, Obata K, Watanabe M, Hashikawa T, Tanaka K (2006) From the cover: indispensability of the glutamate transporters GLAST and GLT1 to brain development. Proc Natl Acad Sci U S A 103:12161–12166

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  20. Melendez RI, Vuthiganon J, Kalivas PW (2005) Regulation of extracellular glutamate in the prefrontal cortex: focus on the cystine glutamate exchanger and group I metabotropic glutamate receptors. J Pharmacol Exp Ther 314:139–147

    CAS  Article  PubMed  Google Scholar 

  21. Moore DJ, Masliah E, Rippeth JD, Gonzalez R, Carey CL, Cherner M, Ellis RJ, Achim CL, Marcotte TD, Heaton RK, Grant I, Group HNRC (2006) Cortical and subcortical neurodegeneration is associated with HIV neurocognitive impairment. AIDS 20:879–887. doi:10.1097/01.aids.0000218552.69834.00

    Article  PubMed  Google Scholar 

  22. Murphy TH, Miyamoto M, Sastre A, Schnaar RL, Coyle JT (1989) Glutamate toxicity in a neuronal cell line involves inhibition of cystine transport leading to oxidative stress. Neuron 2:1547–1558

    CAS  Article  PubMed  Google Scholar 

  23. Nakamura Y, Iga K, Shibata T, Shudo M, Kataoka K (1993) Glial plasmalemmal vesicles: a subcellular fraction from rat hippocampal homogenate distinct from synaptosomes. Glia 9:48–56. doi:10.1002/glia.440090107

    CAS  Article  PubMed  Google Scholar 

  24. National Research Council (2012) Guide for the care and use of laboratory animals. National Academy Press, Washington, D.C.

  25. Nieoullon A, Canolle B, Masmejean F, Guillet B, Pisano P, Lortet S (2006) The neuronal excitatory amino acid transporter EAAC1/EAAT3: does it represent a major actor at the brain excitatory synapse? J Neurochem 98:1007–1018

    CAS  Article  PubMed  Google Scholar 

  26. Patel SA, Warren BA, Rhoderick JF, Bridges RJ (2004) Differentiation of substrate and non-substrate inhibitors of transport system xc(−): an obligate exchanger of L-glutamate and L-cystine. Neuropharmacology 46:273–284

    CAS  Article  PubMed  Google Scholar 

  27. Patton HK, Zhou ZH, Bubien JK, Benveniste EN, Benos DJ (2000) gp120-induced alterations of human astrocyte function: Na(+)/H(+) exchange, K(+) conductance, and glutamate flux. Am J Physiol Cell Physiol 279:C700–C708

    CAS  PubMed  Google Scholar 

  28. Paxinos G, Franklin K (2012) The mouse brain in stereotaxic coordinates, 4th edn. Academic Press, San Diego, CA

  29. Pocernich CB, Sultana R, Hone E, Turchan J, Martins RN, Calabrese V, Nath A, Butterfield DA (2004) Effects of apolipoprotein E on the human immunodeficiency virus protein Tat in neuronal cultures and synaptosomes. J Neurosci Res 77:532–539. doi:10.1002/jnr.20182

    CAS  Article  PubMed  Google Scholar 

  30. Rothstein JD, Martin L, Levey AI, Dykes-Hoberg M, Jin L, Wu D, Nash N, Kuncl RW (1994) Localization of neuronal and glial glutamate transporters. Neuron 13:713–725

    CAS  Article  PubMed  Google Scholar 

  31. Scimemi A, Tian H, Diamond JS (2009) Neuronal transporters regulate glutamate clearance, NMDA receptor activation, and synaptic plasticity in the hippocampus. J Neurosci 29:14581–14595. doi:10.1523/JNEUROSCI.4845-09.2009

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  32. Shi B, Raina J, Lorenzo A, Busciglio J, Gabuzda D (1998) Neuronal apoptosis induced by HIV-1 Tat protein and TNF-alpha: potentiation of neurotoxicity mediated by oxidative stress and implications for HIV-1 dementia. J Neurovirol 4:281–290

    CAS  Article  PubMed  Google Scholar 

  33. Suchak SK, Baloyianni NV, Perkinton MS, Williams RJ, Meldrum BS, Rattray M (2003) The ‘glial’ glutamate transporter, EAAT2 (Glt-1) accounts for high affinity glutamate uptake into adult rodent nerve endings. J Neurochem 84:522–532

    CAS  Article  PubMed  Google Scholar 

  34. Toggas SM, Masliah E, Rockenstein EM, Rall GF, Abraham CR, Mucke L (1994) Central nervous system damage produced by expression of the HIV-1 coat protein gp120 in transgenic mice. Nature 367:188–193. doi:10.1038/367188a0

    CAS  Article  PubMed  Google Scholar 

  35. Vesce S, Bezzi P, Rossi D, Meldolesi J, Volterra A (1997) HIV-1 gp120 glycoprotein affects the astrocyte control of extracellular glutamate by both inhibiting the uptake and stimulating the release of the amino acid. FEBS Lett 411:107–109

    CAS  Article  PubMed  Google Scholar 

  36. Wang Z, Pekarskaya O, Bencheikh M, Chao W, Gelbard HA, Ghorpade A, Rothstein JD, Volsky DJ (2003) Reduced expression of glutamate transporter EAAT2 and impaired glutamate transport in human primary astrocytes exposed to HIV-1 or gp120. Virology 312:60–73

    CAS  Article  PubMed  Google Scholar 

  37. Waxman EA, Baconguis I, Lynch DR, Robinson MB (2007) N-methyl-D-aspartate receptor-dependent regulation of the glutamate transporter excitatory amino acid carrier 1. J Biol Chem 282:17594–17607

    CAS  Article  PubMed  Google Scholar 

  38. Wiley CA, Soontornniyomkij V, Radhakrishnan L, Masliah E, Mellors J, Hermann SA, Dailey P, Achim CL (1998) Distribution of brain HIV load in AIDS. Brain Pathol 8:277–284

    CAS  Article  PubMed  Google Scholar 

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Acknowledgments

All authors approved the final version of this article. The authors would like to thank L. Perez for his excellent technical assistance. This work was supported in part by National Institutes of Health Grants SNRP-U54N54301, 2R25GM061151 and NIGMS 1P20GM103642.

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Correspondence to Roberto I. Melendez.

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All protocols were approved by the Institutional Animal Care and Use Committee at the UPR-SOM and in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals (2012) and AVMA Guidelines for the Euthanasia of Animals (2013).

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The authors declare that there is no conflict of interests.

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Melendez, R.I., Roman, C., Capo-Velez, C.M. et al. Decreased glial and synaptic glutamate uptake in the striatum of HIV-1 gp120 transgenic mice. J. Neurovirol. 22, 358–365 (2016). https://doi.org/10.1007/s13365-015-0403-6

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Keywords

  • Glutamate transporters
  • gp120
  • HIV-1
  • Striatum
  • Cognitive deficits