Mitochondrial glutaminase release contributes to glutamate-mediated neurotoxicity during human immunodeficiency virus-1 infection

Changhai Tian, Lijun Sun, Beibei Jia, Kangmu Ma, Norman Curthoys, Jianqing Ding, Jialin Zheng

Research output: Contribution to journalArticlepeer-review

24 Scopus citations

Abstract

Human immunodeficiency virus (HIV) induces a neurological disease culminating in frank dementia referred to as HIV-associated dementia (HAD). Neurotoxins from HIV-1-infected and activated mononuclear phagocytes contribute to the neuropathogenesis of HAD. Glutamate is the predominant excitatory neurotransmitter in the mammalian central nervous system (CNS) and functions through activation of multiple receptors. Excessive glutamate production by HIV-infected macrophages in HAD may contribute to neuronal injury. Our previous studies have suggested that mitochondrial glutaminase is responsible for the excessive production of glutamate. However, how HIV-1 infection regulates glutamate over-production remains unclear. In this study, we propose that HIV infection-induced oxidative stress contributes to mitochondrial glutaminase release, which results in the excessive production of glutamate and subsequent neuronal injury. We collected conditioned media from HIV-1 infected macrophages and analyzed glutamate concentration in the media by RPHPLC, and found that the cyclosporine A (CsA), an inhibitor of HIV-1 replication and mitochondrial permeability transition pore, and N-acetylcysteine (NAC), a remover of reactive oxygen species (ROS), not only blocked the excessive glutamate production, but also decreased the glutamate-mediated neurotoxicity. In addition, HIVinfection- induced ROS generation was accompanied with the excessive glutamate production, suggesting that oxidative stress was involved in glutamate regulation. Using the isolated rat brain mitochondria as an ex vivo model and over-expressing GFP-glutaminase fusion protein in mammalian cells as a cell model, we confirm oxidative stress-mediated mitochondrial glutaminase release during HIV-1 infection contributes to glutamate over-production and the subsequent neurotoxicity. These results may provide insight into HAD pathogenesis and a therapeutic strategy for HAD treatment.

Original languageEnglish
Pages (from-to)619-628
Number of pages10
JournalJournal of NeuroImmune Pharmacology
Volume7
Issue number3
DOIs
StatePublished - Sep 2012

Bibliographical note

Funding Information:
Acknowledgements We kindly thank Dr. Terry D. Hexum for comments on the manuscript and Drs.Yunlong Huang, Hui Peng, Ling Ye, Lixia Zhao, Myhanh Che, Li Wu and Kristin Leland Wavrin, who provided support for this work. Julie Ditter, Lenal M Bottoms, Johna Belling, and Robin Taylor provided outstanding administrative and secretarial support. This work was supported in part by research grants by the National Institutes of Health: R01 NS 41858–01, R01 NS 061642–01, 3R01NS61642-2S1, R21 MH 083525–01, P01 NS043985, and P20 RR15635-01 (JZ) and National Natural Science Foundation of China (NSFC) # 81028007.

Keywords

  • Glutamate and neurotoxicity
  • HIV-1 infection
  • Mitochondrial glutaminase
  • Oxidative stress

ASJC Scopus subject areas

  • Neuroscience (miscellaneous)
  • Immunology and Allergy
  • Immunology
  • Pharmacology

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