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Ewens AN, Pilski A, Hastings SD, Krook-Magnuson C, Graves SM, Krook-Magnuson E, Thayer SA. Levetiracetam Prevents Neurophysiological Changes and Preserves Cognitive Function in the Human Immunodeficiency Virus (HIV)-1 Transactivator of Transcription Transgenic Mouse Model of HIV-Associated Neurocognitive Disorder. J Pharmacol Exp Ther 2024; 391:104-118. [PMID: 39060163 DOI: 10.1124/jpet.124.002272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/24/2024] [Accepted: 07/22/2024] [Indexed: 07/28/2024] Open
Abstract
Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) affects nearly half of the 39 million people living with HIV. HAND symptoms range from subclinical cognitive impairment to dementia; the mechanisms that underlie HAND remain unclear and there is no treatment. The HIV protein transactivator of transcription (TAT) is thought to contribute to HAND because it persists in the central nervous system and elicits neurotoxicity in animal models. Network hyperexcitability is associated with accelerated cognitive decline in neurodegenerative disorders. Here we show that the antiepileptic drug levetiracetam (LEV) attenuated aberrant excitatory synaptic transmission, protected synaptic plasticity, reduced seizure susceptibility, and preserved cognition in inducible TAT (iTAT) transgenic male mice. iTAT mice had an increased frequency of spontaneous excitatory postsynaptic currents in hippocampal slice recordings and impaired long-term potentiation, a form of synaptic plasticity that underlies learning and memory. Two-week administration of LEV by osmotic minipump prevented both impairments. Kainic acid administered to iTAT mice induced a higher maximum behavioral seizure score, longer seizure duration, and shorter latency to first seizure, consistent with a lower seizure threshold. LEV treatment prevented these in vivo signs of hyperexcitability. Lastly, in the Barnes maze, iTAT mice required more time to reach the goal, committed more errors, and received lower cognitive scores relative to iTAT mice treated with LEV. Thus, TAT expression drives functional deficits, suggesting a causative role in HAND. As LEV not only prevented aberrant synaptic activity in iTAT mice but also prevented cognitive dysfunction, it may provide a promising pharmacological approach to the treatment of HAND. SIGNIFICANCE STATEMENT: Approximately half of people living with human immunodeficiency virus (HIV) also suffer from HIV-associated neurocognitive disorder (HAND), for which there is no treatment. The HIV protein transactivator of transcription (TAT) causes toxicity that is thought to contribute to HAND. Here, the antiepileptic drug levetiracetam (LEV) prevented synaptic and cognitive impairments in a TAT-expressing mouse. LEV is widely used to treat seizures and is well-tolerated in humans, including those with HIV. This study supports further investigation of LEV-mediated neuroprotection in HAND.
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Affiliation(s)
- Ashley N Ewens
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota (A.N.E., A.P., S.M.G., S.A.T.); and Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota (S.D.H., C.K.-M., E.K.-M.)
| | - Alexander Pilski
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota (A.N.E., A.P., S.M.G., S.A.T.); and Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota (S.D.H., C.K.-M., E.K.-M.)
| | - Shayne D Hastings
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota (A.N.E., A.P., S.M.G., S.A.T.); and Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota (S.D.H., C.K.-M., E.K.-M.)
| | - Chris Krook-Magnuson
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota (A.N.E., A.P., S.M.G., S.A.T.); and Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota (S.D.H., C.K.-M., E.K.-M.)
| | - Steven M Graves
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota (A.N.E., A.P., S.M.G., S.A.T.); and Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota (S.D.H., C.K.-M., E.K.-M.)
| | - Esther Krook-Magnuson
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota (A.N.E., A.P., S.M.G., S.A.T.); and Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota (S.D.H., C.K.-M., E.K.-M.)
| | - Stanley A Thayer
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota (A.N.E., A.P., S.M.G., S.A.T.); and Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota (S.D.H., C.K.-M., E.K.-M.)
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Carey SD, Conant K, Maguire-Zeiss KA. Short-term exposure to HIV Tat induces glial activation and changes in perineuronal nets. Eur J Neurosci 2024; 60:4303-4316. [PMID: 38844747 DOI: 10.1111/ejn.16427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 04/30/2024] [Accepted: 05/14/2024] [Indexed: 08/07/2024]
Abstract
Despite widespread use of combination antiretroviral therapy (cART), there remains a subset of individuals who display cognitive impairment broadly known as HIV-associated neurocognitive disorder (HAND). Interestingly, HIV-infected cells continuously release the HIV-1 protein Tat even in the presence of cART. Persistent exposure to Tat is proposed to increase both neuroinflammation and neurotoxicity. In vitro evidence shows that matrix metalloproteinases (MMPs) are among the neuroinflammatory molecules induced by Tat, which are known to disrupt specialized neuronal extracellular matrix structures called perineuronal nets (PNNs). PNNs predominantly surround parvalbumin interneurons and help to buffer these cells from oxidant stress and to independently increase their excitability. In order to better understand the link between short-term exposure to Tat, neuroinflammation, and PNNs, we explored the direct effects of Tat on glial cells and neurons. Herein, we report that in mixed glial cultures, Tat directly increases the expression of proinflammatory molecules, including MMP-9. Moreover, direct injection of Tat protein into mouse hippocampus increases the expression of astrocyte and microglia markers as well as MMP-9. The number of PNNs is decreased following Tat exposure, followed later by decreased numbers of hippocampal parvalbumin-expressing neurons. In older mice, Tat induced significant increases in the gene expression of proinflammatory molecules including markers of gliosis, MMPs and complement system proteins. Taken together, these data support a direct effect of Tat on glial-derived MMP expression subsequently affecting PNNs and neuronal health, with older mice more susceptible to Tat-induced inflammation.
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Affiliation(s)
- Sean D Carey
- Department of Biology, Georgetown University, Washington DC, United States
| | - Katherine Conant
- Department of Neuroscience, Georgetown University School of Medicine, Washington DC, United States
| | - Kathleen A Maguire-Zeiss
- Department of Neuroscience, Georgetown University School of Medicine, Washington DC, United States
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Thirion A, Loots DT, Williams ME, Solomons R, Mason S. 1H-NMR metabolomics investigation of CSF from children with HIV reveals altered neuroenergetics due to persistent immune activation. Front Neurosci 2024; 18:1270041. [PMID: 38745940 PMCID: PMC11091326 DOI: 10.3389/fnins.2024.1270041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 04/15/2024] [Indexed: 05/16/2024] Open
Abstract
Background HIV can invade the central nervous system (CNS) early during infection, invading perivascular macrophages and microglia, which, in turn, release viral particles and immune mediators that dysregulate all brain cell types. Consequently, children living with HIV often present with neurodevelopmental delays. Methods In this study, we used proton nuclear magnetic resonance (1H-NMR) spectroscopy to analyze the neurometabolic profile of HIV infection using cerebrospinal fluid samples obtained from 17 HIV+ and 50 HIV- South African children. Results Nine metabolites, including glucose, lactate, glutamine, 1,2-propanediol, acetone, 3-hydroxybutyrate, acetoacetate, 2-hydroxybutyrate, and myo-inositol, showed significant differences when comparing children infected with HIV and those uninfected. These metabolites may be associated with activation of the innate immune response and disruption of neuroenergetics pathways. Conclusion These results elucidate the neurometabolic state of children infected with HIV, including upregulation of glycolysis, dysregulation of ketone body metabolism, and elevated reactive oxygen species production. Furthermore, we hypothesize that neuroinflammation alters astrocyte-neuron communication, lowering neuronal activity in children infected with HIV, which may contribute to the neurodevelopmental delay often observed in this population.
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Affiliation(s)
- Anicia Thirion
- Department of Biochemistry, Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, South Africa
| | - Du Toit Loots
- Department of Biochemistry, Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, South Africa
| | - Monray E. Williams
- Department of Biochemistry, Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, South Africa
| | - Regan Solomons
- Department of Pediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Shayne Mason
- Department of Biochemistry, Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, South Africa
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Zaongo SD, Harypursat V, Rashid F, Dahourou DL, Ouedraogo AS, Chen Y. Influence of HIV infection on cognition and overall intelligence in HIV-infected individuals: advances and perspectives. Front Behav Neurosci 2023; 17:1261784. [PMID: 37953826 PMCID: PMC10637382 DOI: 10.3389/fnbeh.2023.1261784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 10/10/2023] [Indexed: 11/14/2023] Open
Abstract
It is now well understood that HIV-positive individuals, even those under effective ART, tend to develop a spectrum of cognitive, motor, and/or mood conditions which are contemporarily referred to as HIV-associated neurocognitive disorder (HAND), and which is directly related to HIV-1 infection and HIV-1 replication in the central nervous system (CNS). As HAND is known to induce difficulties associated with attention, concentration, and memory, it is thus legitimate and pertinent to speculate upon the possibility that HIV infection may well influence human cognition and intelligence. We therefore propose herein to review the concept of intelligence, the concept of cells of intelligence, the influence of HIV on these particular cells, and the evidence pointing to differences in observed intelligence quotient (IQ) scores between HIV-positive and HIV-negative individuals. Additionally, cumulative research evidence continues to draw attention to the influence of the gut on human intelligence. Up to now, although it is known that HIV infection profoundly alters both the composition and diversity of the gut microbiota and the structural integrity of the gut, the influence of the gut on intelligence in the context of HIV infection remains poorly described. As such, we also provide herein a review of the different ways in which HIV may influence human intelligence via the gut-brain axis. Finally, we provide a discourse on perspectives related to HIV and human intelligence which may assist in generating more robust evidence with respect to this issue in future studies. Our aim is to provide insightful knowledge for the identification of novel areas of investigation, in order to reveal and explain some of the enigmas related to HIV infection.
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Affiliation(s)
- Silvere D. Zaongo
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
| | - Vijay Harypursat
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
| | - Farooq Rashid
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
| | - Désiré Lucien Dahourou
- Département Biomédical/Santé Publique, Institut de Recherche en Sciences de la Santé/CNRST, Ouagadougou, Burkina Faso
| | - Abdoul-Salam Ouedraogo
- Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Department of Bacteriology and Virology, Souro Sanou University Hospital, Bobo-Dioulasso, Burkina Faso
| | - Yaokai Chen
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
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Scanlan A, Zhang Z, Koneru R, Reece M, Gavegnano C, Anderson AM, Tyor W. A Rationale and Approach to the Development of Specific Treatments for HIV Associated Neurocognitive Impairment. Microorganisms 2022; 10:2244. [PMID: 36422314 PMCID: PMC9699382 DOI: 10.3390/microorganisms10112244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/03/2022] [Accepted: 11/08/2022] [Indexed: 05/22/2024] Open
Abstract
Neurocognitive impairment (NCI) associated with HIV infection of the brain impacts a large proportion of people with HIV (PWH) regardless of antiretroviral therapy (ART). While the number of PWH and severe NCI has dropped considerably with the introduction of ART, the sole use of ART is not sufficient to prevent or arrest NCI in many PWH. As the HIV field continues to investigate cure strategies, adjunctive therapies are greatly needed. HIV imaging, cerebrospinal fluid, and pathological studies point to the presence of continual inflammation, and the presence of HIV RNA, DNA, and proteins in the brain despite ART. Clinical trials exploring potential adjunctive therapeutics for the treatment of HIV NCI over the last few decades have had limited success. Ideally, future research and development of novel compounds need to address both the HIV replication and neuroinflammation associated with HIV infection in the brain. Brain mononuclear phagocytes (MPs) are the primary instigators of inflammation and HIV protein expression; therefore, adjunctive treatments that act on MPs, such as immunomodulating agents, look promising. In this review, we will highlight recent developments of innovative therapies and discuss future approaches for HIV NCI treatment.
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Affiliation(s)
- Aaron Scanlan
- Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Zhan Zhang
- Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Rajeth Koneru
- Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA
| | - Monica Reece
- Department of Pathology, Division of Experimental Pathology, Emory University, Atlanta, GA 30322, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA 30322, USA
| | - Christina Gavegnano
- Department of Pathology, Division of Experimental Pathology, Emory University, Atlanta, GA 30322, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA 30322, USA
| | - Albert M. Anderson
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - William Tyor
- Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
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Aberrant Synaptic Pruning in CNS Diseases: A Critical Player in HIV-Associated Neurological Dysfunction? Cells 2022; 11:cells11121943. [PMID: 35741071 PMCID: PMC9222069 DOI: 10.3390/cells11121943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/28/2022] [Accepted: 06/14/2022] [Indexed: 02/04/2023] Open
Abstract
Even in the era of effective antiretroviral therapies, people living with Human Immunodeficiency Virus (HIV) are burdened with debilitating neurological dysfunction, such as HIV-associated neurocognitive disorders (HAND) and HIV-associated pain, for which there are no FDA approved treatments. Disruption to the neural circuits of cognition and pain in the form of synaptic degeneration is implicated in developing these dysfunctions. Glia-mediated synaptic pruning is a mechanism of structural plasticity in the healthy central nervous system (CNS), but recently, it has been discovered that dysregulated glia-mediated synaptic pruning is the cause of synaptic degeneration, leading to maladaptive plasticity and cognitive deficits in multiple diseases of the CNS. Considering the essential contribution of activated glial cells during the development of HAND and HIV-associated pain, it is possible that glia-mediated synaptic pruning is the causative mechanism of synaptic degeneration induced by HIV. This review will analyze the known examples of synaptic pruning during disease in order to better understand how this mechanism could contribute to the progression of HAND and HIV-associated pain.
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7
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Wang L, Zeng Y, Zhou Y, Yu J, Liang M, Qin L, Zhou Y. Win55,212-2 Improves Neural Injury induced by HIV-1 Glycoprotein 120 in Rats by Exciting CB2R. Brain Res Bull 2022; 182:67-79. [DOI: 10.1016/j.brainresbull.2022.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/29/2022] [Accepted: 02/07/2022] [Indexed: 12/12/2022]
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8
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Longitudinal trajectories of brain volume in combined antiretroviral therapy treated and untreated simian immunodeficiency virus-infected rhesus macaques. AIDS 2021; 35:2433-2443. [PMID: 34870927 PMCID: PMC8631166 DOI: 10.1097/qad.0000000000003055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES We used simian immunodeficiency virus (SIV)-infected nonhuman primates to investigate longitudinal changes of brain volume caused by SIV and the effect of combined antiretroviral therapy (cART). In addition, the relation between viral load, immune status, and brain volume were explored. DESIGN A longitudinal study of two healthy controls, five SIVmac239-infected macaques received cART (SIV+cART+) at 40 days postinnoculation, and five SIVmac239-infected macaques received no therapy (SIV+cART-). METHODS Structural T1-weighted MRI, blood and cerebrospinal fluid testing were acquired at multiple time points for 48 weeks postinfection (wpi). Brain volume was estimated using region of interest (ROI)-based analysis. Volume differences were compared among three groups. Linear regression models tested the associations between brain volumes and biomarkers (viral load, CD4+ T-cell count, CD4+/CD8+ ratio). RESULTS In our model, brain volume alteration in SIV-infected macaques can be detected at 12 wpi in several brain regions. As the infection progresses, the SIV+cART- macaques displayed generalized gray matter atrophy at the endpoint. Though initiate cART right after acute infection, SIV+cART+ macaques still displayed brain atrophy but showed signs of reversibility. Plasma viral load is mainly associated with subcortical nucleus volume whereas CD4+ T-cell count and CD4+/CD8+ ratio in plasma were associated with widespread cortical volume. CONCLUSION The SIVmac239-infected Chinese origin macaque is a valid model for neuroHIV. Brain atrophy caused by SIV infection can be relieved, even reversed, by cART. Our model also provides new insights into understanding the pathogenesis of brain injury in people with HIV (PWH).
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Denton AR, Mactutus CF, Lateef AU, Harrod SB, Booze RM. Chronic SSRI treatment reverses HIV-1 protein-mediated synaptodendritic damage. J Neurovirol 2021; 27:403-421. [PMID: 34003469 PMCID: PMC8504184 DOI: 10.1007/s13365-021-00960-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/11/2021] [Accepted: 02/17/2021] [Indexed: 02/07/2023]
Abstract
HIV-1 infection affects approximately 37 million individuals, and approximately 50% of seropositive individuals will develop symptoms of clinical depression and/or apathy. Dysfunctions of both serotonergic and dopaminergic neurotransmission have been implicated in the pathogenesis of motivational alterations. The present study evaluated the efficacy of a SSRI (escitalopram) in the HIV-1 transgenic (Tg) rat. Behavioral, neurochemical, and neuroanatomical outcomes with respect to HIV-1 and sex were evaluated to determine the efficacy of chronic escitalopram treatment. Escitalopram treatment restored function in each of the behavioral tasks that were sensitive to HIV-1-induced impairments. Further, escitalopram treatment restored HIV-1-mediated synaptodendritic damage in the nucleus accumbens; treatment with escitalopram significantly increased dendritic proliferation in HIV-1 Tg rats. However, restoration did not consistently occur with the neurochemical analysis in the HIV-1 rat. Taken together, these results suggest a role for SSRI therapies in repairing long-term HIV-1 protein-mediated neuronal damage and restoring function.
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Affiliation(s)
- Adam R Denton
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, South Carolina, USA
| | - Charles F Mactutus
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, South Carolina, USA
| | - Almeera U Lateef
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, South Carolina, USA
| | - Steven B Harrod
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, South Carolina, USA
| | - Rosemarie M Booze
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, South Carolina, USA.
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Marks WD, Paris JJ, Barbour AJ, Moon J, Carpenter VJ, McLane VD, Lark ARS, Nass SR, Zhang J, Yarotskyy V, McQuiston AR, Knapp PE, Hauser KF. HIV-1 Tat and Morphine Differentially Disrupt Pyramidal Cell Structure and Function and Spatial Learning in Hippocampal Area CA1: Continuous versus Interrupted Morphine Exposure. eNeuro 2021; 8:ENEURO.0547-20.2021. [PMID: 33782102 PMCID: PMC8146490 DOI: 10.1523/eneuro.0547-20.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/27/2021] [Accepted: 03/10/2021] [Indexed: 02/06/2023] Open
Abstract
About half the people infected with human immunodeficiency virus (HIV) have neurocognitive deficits that often include memory impairment and hippocampal deficits, which can be exacerbated by opioid abuse. To explore the effects of opioids and HIV on hippocampal CA1 pyramidal neuron structure and function, we induced HIV-1 transactivator of transcription (Tat) expression in transgenic mice for 14 d and co-administered time-release morphine or vehicle subcutaneous implants during the final 5 d (days 9-14) to establish steady-state morphine levels. Morphine was withheld from some ex vivo slices during recordings to begin to assess the initial pharmacokinetic consequences of opioid withdrawal. Tat expression reduced hippocampal CA1 pyramidal neuronal excitability at lower stimulating currents. Pyramidal cell firing rates were unaffected by continuous morphine exposure. Behaviorally, exposure to Tat or high dosages of morphine impaired spatial memory Exposure to Tat and steady-state levels of morphine appeared to have largely independent effects on pyramidal neuron structure and function, a response that is distinct from other vulnerable brain regions such as the striatum. By contrast, acutely withholding morphine (from morphine-tolerant ex vivo slices) revealed unique and selective neuroadaptive shifts in CA1 pyramidal neuronal excitability and dendritic plasticity, including some interactions with Tat. Collectively, the results show that opioid-HIV interactions in hippocampal area CA1 are more nuanced than previously assumed, and appear to vary depending on the outcome assessed and on the pharmacokinetics of morphine exposure.
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Affiliation(s)
- William D Marks
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
| | - Jason J Paris
- Department of BioMolecular Sciences, University of Mississippi, School of Pharmacy, University, MS 38677-1848
| | - Aaron J Barbour
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298-0709
| | - Jean Moon
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
| | - Valerie J Carpenter
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
| | - Virginia D McLane
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
| | - Arianna R S Lark
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
| | - Sara R Nass
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
| | - Jingli Zhang
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
| | - Viktor Yarotskyy
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
| | - A Rory McQuiston
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298-0709
| | - Pamela E Knapp
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298-0709
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, VA 23298-0709
| | - Kurt F Hauser
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0613
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298-0709
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, VA 23298-0709
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Hermes DJ, Yadav-Samudrala BJ, Xu C, Paniccia JE, Meeker RB, Armstrong ML, Reisdorph N, Cravatt BF, Mackie K, Lichtman AH, Ignatowska-Jankowska BM, Lysle DT, Fitting S. GPR18 drives FAAH inhibition-induced neuroprotection against HIV-1 Tat-induced neurodegeneration. Exp Neurol 2021; 341:113699. [PMID: 33736974 PMCID: PMC8984429 DOI: 10.1016/j.expneurol.2021.113699] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 02/05/2021] [Accepted: 03/11/2021] [Indexed: 02/03/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) is known to provoke microglial immune responses which likely play a paramount role in the development of chronic neuroinflammatory conditions and neuronal damage related to HIV-1 associated neurocognitive disorders (HAND). In particular, HIV-1 Tat protein is a proinflammatory neurotoxin which predisposes neurons to synaptodendritic injury. Drugs targeting the degradative enzymes of endogenous cannabinoids have shown promise in reducing inflammation with minimal side effects in rodent models. Considering that markers of neuroinflammation can predict the extent of neuronal injury in HAND patients, we evaluated the neurotoxic effect of HIV-1 Tat-exposed microglia following blockade of fatty acid amid hydrolyze (FAAH), a catabolic enzyme responsible for degradation of endocannabinoids, e.g. anandamide (AEA). In the present study, cultured murine microglia were incubated with Tat and/or a FAAH inhibitor (PF3845). After 24 h, cells were imaged for morphological analysis and microglial conditioned media (MCM) was collected. Frontal cortex neuron cultures (DIV 7–11) were then exposed to MCM, and neurotoxicity was assessed via live cell calcium imaging and staining of actin positive dendritic structures. Results demonstrate a strong attenuation of microglial responses to Tat by PF3845 pretreatment, which is indicated by 1) microglial changes in morphology to a less proinflammatory phenotype using fractal analysis, 2) a decrease in release of neurotoxic cytokines/chemokines (MCP-1/CCL2) and matrix metalloproteinases (MMPs; MMP-9) using ELISA/multiplex assays, and 3) enhanced production of endocannabinoids (AEA) using LC/MS/MS. Additionally, PF3845’s effects on Tat-induced microglial-mediated neurotoxicity, decreased dysregulation of neuronal intracellular calcium and prevented the loss of actin-positive staining and punctate structure in frontal cortex neuron cultures. Interestingly, these observed neuroprotective effects appeared to be independent of cannabinoid receptor activity (CB1R & CB2R). We found that a purported GPR18 antagonist, CID-85469571, blocked the neuroprotective effects of PF3845 in all experiments. Collectively, these experiments increase understanding of the role of FAAH inhibition and Tat in mediating microglial neurotoxicity in the HAND condition.
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Affiliation(s)
- Douglas J Hermes
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America.
| | - Barkha J Yadav-Samudrala
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Changqing Xu
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Jacqueline E Paniccia
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Rick B Meeker
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Michael L Armstrong
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Denver, CO, United States of America
| | - Nichole Reisdorph
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Denver, CO, United States of America
| | - Benjamin F Cravatt
- Department of Chemistry, Scripps Research Institute, La Jolla, CA, United States of America
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States of America
| | - Aron H Lichtman
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States of America
| | | | - Donald T Lysle
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Sylvia Fitting
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America.
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12
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Irollo E, Luchetta J, Ho C, Nash B, Meucci O. Mechanisms of neuronal dysfunction in HIV-associated neurocognitive disorders. Cell Mol Life Sci 2021; 78:4283-4303. [PMID: 33585975 PMCID: PMC8164580 DOI: 10.1007/s00018-021-03785-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 01/14/2021] [Accepted: 01/29/2021] [Indexed: 12/13/2022]
Abstract
HIV-associated neurocognitive disorder (HAND) is characterized by cognitive and behavioral deficits in people living with HIV. HAND is still common in patients that take antiretroviral therapies, although they tend to present with less severe symptoms. The continued prevalence of HAND in treated patients is a major therapeutic challenge, as even minor cognitive impairment decreases patient’s quality of life. Therefore, modern HAND research aims to broaden our understanding of the mechanisms that drive cognitive impairment in people with HIV and identify promising molecular pathways and targets that could be exploited therapeutically. Recent studies suggest that HAND in treated patients is at least partially induced by subtle synaptodendritic damage and disruption of neuronal networks in brain areas that mediate learning, memory, and executive functions. Although the causes of subtle neuronal dysfunction are varied, reversing synaptodendritic damage in animal models restores cognitive function and thus highlights a promising therapeutic approach. In this review, we examine evidence of synaptodendritic damage and disrupted neuronal connectivity in HAND from clinical neuroimaging and neuropathology studies and discuss studies in HAND models that define structural and functional impairment of neurotransmission. Then, we report molecular pathways, mechanisms, and comorbidities involved in this neuronal dysfunction, discuss new approaches to reverse neuronal damage, and highlight current gaps in knowledge. Continued research on the manifestation and mechanisms of synaptic injury and network dysfunction in HAND patients and experimental models will be critical if we are to develop safe and effective therapies that reverse subtle neuropathology and cognitive impairment.
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Affiliation(s)
- Elena Irollo
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA
| | - Jared Luchetta
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA
| | - Chunta Ho
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA
| | - Bradley Nash
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA
| | - Olimpia Meucci
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA. .,Department of Microbiology and Immunology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA. .,Center for Neuroimmunology and CNS Therapeutics, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA.
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13
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Xiang Y, Xin J, Le W, Yang Y. Neurogranin: A Potential Biomarker of Neurological and Mental Diseases. Front Aging Neurosci 2020; 12:584743. [PMID: 33132903 PMCID: PMC7573493 DOI: 10.3389/fnagi.2020.584743] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022] Open
Abstract
Neurogranin (Ng) is a small protein usually expressed in granule-like structures in pyramidal cells of the hippocampus and cortex. However, its clinical value is not fully clear so far. Currently, Ng is proved to be involved in synaptic plasticity, synaptic regeneration, and long-term potentiation mediated by the calcium- and calmodulin-signaling pathways. Due to both the synaptic integrity and function as the growing concerns in the pathogenesis of a wide variety of neurological and mental diseases, a series of researches published focused on the associations between Ng and these kinds of diseases in the past decade. Therefore, in this review, we highlight several diseases, which include, but are not limited to, Alzheimer’s disease, Parkinson disease, Creutzfeldt–Jakob disease, neuro-HIV, neurosyphilis, schizophrenia, depression, traumatic brain injury, and acute ischemic stroke, and summarize the associations between cerebrospinal fluid or blood-derived Ng with these diseases. We propose that Ng is a potential and promising biomarker to improve the diagnosis, prognosis, and severity evaluation of these diseases in the future.
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Affiliation(s)
- Yang Xiang
- Institute of Neuroscience, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Clinical Medicine, University of Electronic Science and Technology of China, Chengdu, China.,Department of Neurology, General Hospital of Western Theater Command, Chengdu, China
| | - Jiayan Xin
- North Sichuan Medical College, Nanchong, China.,Department of Neurology, General Hospital of Western Theater Command, Chengdu, China
| | - Weidong Le
- Institute of Neuroscience, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Clinical Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Yongjian Yang
- Department of Cardiovasology, General Hospital of Western Theater Command, Chengdu, China
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14
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Ghatak S, Talantova M, McKercher SR, Lipton SA. Novel Therapeutic Approach for Excitatory/Inhibitory Imbalance in Neurodevelopmental and Neurodegenerative Diseases. Annu Rev Pharmacol Toxicol 2020; 61:701-721. [PMID: 32997602 DOI: 10.1146/annurev-pharmtox-032320-015420] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Excitatory/inhibitory (E/I) balance, defined as the balance between excitation and inhibition of synaptic activity in a neuronal network, accounts in part for the normal functioning of the brain, controlling, for example, normal spike rate. In many pathological conditions, this fine balance is perturbed, leading to excessive or diminished excitation relative to inhibition, termed E/I imbalance, reflected in network dysfunction. E/I imbalance has emerged as a contributor to neurological disorders that occur particularly at the extremes of life, including autism spectrum disorder and Alzheimer's disease, pointing to the vulnerability of neuronal networks at these critical life stages. Hence, it is important to develop approaches to rebalance neural networks. In this review, we describe emerging therapies that can normalize the E/I ratio or the underlying abnormality that contributes to the imbalance in electrical activity, thus improving neurological function in these maladies.
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Affiliation(s)
- Swagata Ghatak
- Department of Molecular Medicine and Neuroscience Translational Center, The Scripps Research Institute, La Jolla, California 92037, USA;
| | - Maria Talantova
- Department of Molecular Medicine and Neuroscience Translational Center, The Scripps Research Institute, La Jolla, California 92037, USA;
| | - Scott R McKercher
- Department of Molecular Medicine and Neuroscience Translational Center, The Scripps Research Institute, La Jolla, California 92037, USA;
| | - Stuart A Lipton
- Department of Molecular Medicine and Neuroscience Translational Center, The Scripps Research Institute, La Jolla, California 92037, USA; .,Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
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15
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Wu MM, Thayer SA. HIV Tat Protein Selectively Impairs CB 1 Receptor-Mediated Presynaptic Inhibition at Excitatory But Not Inhibitory Synapses. eNeuro 2020; 7:ENEURO.0119-20.2020. [PMID: 32471847 PMCID: PMC7307634 DOI: 10.1523/eneuro.0119-20.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/17/2020] [Accepted: 04/26/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the success of antiretroviral therapy in suppressing viral load, nearly half of the 37 million people infected with HIV experience cognitive and motor impairments, collectively classified as HIV-associated neurocognitive disorders (HAND). In the CNS, HIV-infected microglia release neurotoxic agents that act indirectly to elicit excitotoxic synaptic injury. HIV trans-activator of transcription (Tat) protein is one such neurotoxin that is thought to play a major role in the neuropathogenesis of HAND. The endocannabinoid (eCB) system provides on-demand neuroprotection against excitotoxicity, and exogenous cannabinoids attenuate neurotoxicity in animal models of HAND. Whether this neuroprotective system is altered in the presence of HIV is unknown. Here, we examined the effects of Tat on the eCB system in rat primary hippocampal cultures. Using whole-cell patch-clamp electrophysiology, we measured changes in retrograde eCB signaling following exposure to Tat. Treatment with Tat significantly reduced the magnitude of depolarization-induced suppression of excitation (DSE) in a graded manner over the course of 48 h. Interestingly, Tat did not alter this form of short-term synaptic plasticity at inhibitory terminals. The Tat-induced decrease in eCB signaling resulted from impaired CB1 receptor (CB1R)-mediated presynaptic inhibition of glutamate release. This novel loss-of-function was particularly dramatic for low-efficacy agonists such as the eCB 2-arachidonoylglycerol (2-AG) and Δ9-tetrahydrocannabinol (Δ9-THC), the main psychoactive ingredient in marijuana. Our observation that HIV Tat decreases CB1R function in vitro suggests that eCB-mediated neuroprotection may be reduced in vivo; this effect of Tat may contribute to synaptodendritic injury in HAND.
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Affiliation(s)
- Mariah M Wu
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Stanley A Thayer
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455
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16
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Mele AR, Marino J, Dampier W, Wigdahl B, Nonnemacher MR. HIV-1 Tat Length: Comparative and Functional Considerations. Front Microbiol 2020; 11:444. [PMID: 32265877 PMCID: PMC7105873 DOI: 10.3389/fmicb.2020.00444] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/02/2020] [Indexed: 12/22/2022] Open
Affiliation(s)
- Anthony R Mele
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States.,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jamie Marino
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States.,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Will Dampier
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States.,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States.,School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States.,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States.,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States.,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States.,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States
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17
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Wu MM, Zhang X, Asher MJ, Thayer SA. Druggable targets of the endocannabinoid system: Implications for the treatment of HIV-associated neurocognitive disorder. Brain Res 2019; 1724:146467. [PMID: 31539547 DOI: 10.1016/j.brainres.2019.146467] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/24/2022]
Abstract
HIV-associated neurocognitive disorder (HAND) affects nearly half of all HIV-infected individuals. Synaptodendritic damage correlates with neurocognitive decline in HAND, and many studies have demonstrated that HIV-induced neuronal injury results from excitotoxic and inflammatory mechanisms. The endocannabinoid (eCB) system provides on-demand protection against excitotoxicity and neuroinflammation. Here, we discuss evidence of the neuroprotective and anti-inflammatory properties of the eCB system from in vitro and in vivo studies. We examine the pharmacology of the eCB system and evaluate the therapeutic potential of drugs that modulate eCB signaling to treat HAND. Finally, we provide perspective on the need for additional studies to clarify the role of the eCB system in HIV neurotoxicity and speculate that strategies that enhance eCB signaling might slow cognitive decline in HAND.
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Affiliation(s)
- Mariah M Wu
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
| | - Xinwen Zhang
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
| | - Melissa J Asher
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
| | - Stanley A Thayer
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA; Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
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18
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Jacobs IR, Xu C, Hermes DJ, League AF, Xu C, Nath B, Jiang W, Niphakis MJ, Cravatt BF, Mackie K, Mukhopadhyay S, Lichtman AH, Ignatowska-Jankowska BM, Fitting S. Inhibitory Control Deficits Associated with Upregulation of CB 1R in the HIV-1 Tat Transgenic Mouse Model of Hand. J Neuroimmune Pharmacol 2019; 14:661-678. [PMID: 31372820 PMCID: PMC6898753 DOI: 10.1007/s11481-019-09867-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 07/11/2019] [Indexed: 12/14/2022]
Abstract
In the era of combined antiretroviral therapy, HIV-1 infected individuals are living longer lives; however, longevity is met with an increasing number of HIV-1 associated neurocognitive disorders (HAND) diagnoses. The transactivator of transcription (Tat) is known to mediate the neurotoxic effects in HAND by acting directly on neurons and also indirectly via its actions on glia. The Go/No-Go (GNG) task was used to examine HAND in the Tat transgenic mouse model. The GNG task involves subjects discriminating between two stimuli sets in order to determine whether or not to inhibit a previously trained response. Data reveal inhibitory control deficits in female Tat(+) mice (p = .048) and an upregulation of cannabinoid type 1 receptors (CB1R) in the infralimbic (IL) cortex in the same female Tat(+) group (p < .05). A significant negative correlation was noted between inhibitory control and IL CB1R expression (r = −.543, p = .045), with CB1R expression predicting 30% of the variance of inhibitory control (R2 = .295, p = .045). Furthermore, there was a significant increase in spontaneous excitatory postsynaptic current (sEPSC) frequencies in Tat(+) compared to Tat(−) mice (p = .008, across sexes). The increase in sEPSC frequency was significantly attenuated by bath application of PF3845, a fatty acid amide hydrolase (FAAH) enzyme inhibitor (p < .001). Overall, the GNG task is a viable measure to assess inhibitory control deficits in Tat transgenic mice and results suggest a potential therapeutic treatment for the observed deficits with drugs which modulate endocannabinoid enzyme activity. Results of the Go/No-Go operant conditioning task reveal inhibitory control deficits in female transgenic Tat(+) mice without significantly affecting males. The demonstrated inhibitory control deficits appear to be associated with an upregulation of cannabinoid type 1 receptors (CB1R) in the infralimbic (IL) cortex in the same female Tat(+) group. ![]()
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MESH Headings
- AIDS Dementia Complex/genetics
- AIDS Dementia Complex/metabolism
- AIDS Dementia Complex/psychology
- Animals
- Disease Models, Animal
- Female
- HIV-1
- Inhibition, Psychological
- Limbic Lobe/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Neurocognitive Disorders/genetics
- Neurocognitive Disorders/metabolism
- Psychomotor Performance/physiology
- Receptor, Cannabinoid, CB1/biosynthesis
- Receptor, Cannabinoid, CB1/genetics
- Up-Regulation/physiology
- tat Gene Products, Human Immunodeficiency Virus/biosynthesis
- tat Gene Products, Human Immunodeficiency Virus/genetics
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Affiliation(s)
- Ian R Jacobs
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| | - Changqing Xu
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Douglas J Hermes
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Alexis F League
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Callie Xu
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Bhupendra Nath
- Department of Chemistry & Biochemistry, North Carolina Central University, Durham, NC, 27707, USA
| | - Wei Jiang
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, 29425, USA
- Division of Infectious Diseases, Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Micah J Niphakis
- The Skaggs Institute for Chemical Biology, Department of Chemistry, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Benjamin F Cravatt
- The Skaggs Institute for Chemical Biology, Department of Chemistry, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Ken Mackie
- Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
| | - Somnath Mukhopadhyay
- Department of Chemistry & Biochemistry, North Carolina Central University, Durham, NC, 27707, USA
| | - Aron H Lichtman
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | | | - Sylvia Fitting
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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19
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Smith LK, Kuhn TB, Chen J, Bamburg JR. HIV Associated Neurodegenerative Disorders: A New Perspective on the Role of Lipid Rafts in Gp120-Mediated Neurotoxicity. Curr HIV Res 2019; 16:258-269. [PMID: 30280668 PMCID: PMC6398609 DOI: 10.2174/1570162x16666181003144740] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/17/2018] [Accepted: 09/26/2018] [Indexed: 02/07/2023]
Abstract
The implementation of combination antiretroviral therapy (cART) as the primary means of treatment for HIV infection has achieved a dramatic decline in deaths attributed to AIDS and the reduced incidence of severe forms of HIV-associated neurocognitive disorders (HAND) in infected individuals. Despite these advances, milder forms of HAND persist and prevalence of these forms of neurocognitive impairment are rising with the aging population of HIV infected individuals. HIV enters the CNS early in the pathophysiology establishing persistent infection in resident macrophages and glial cells. These infected cells, in turn, secrete neurotoxic viral proteins, inflammatory cytokines, and small metabolites thought to contribute to neurodegenerative processes. The viral envelope protein gp120 has been identified as a potent neurotoxin affecting neurodegeneration via indirect and direct mechanisms involving interactions with chemokine co-receptors CCR5 and CXCR4. This short review focuses on gp120 neurotropism and associated mechanisms of neurotoxicity linked to chemokine receptors CCR5 and CXCR4 with a new perspective on plasma membrane lipid rafts as an active participant in gp120-mediated neurodegeneration underlying HIV induced CNS pathology.
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Affiliation(s)
- Lisa K Smith
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Thomas B Kuhn
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Jack Chen
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - James R Bamburg
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
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20
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Putatunda R, Ho WZ, Hu W. HIV-1 and Compromised Adult Neurogenesis: Emerging Evidence for a New Paradigm of HAND Persistence. AIDS Rev 2019; 21:11-22. [PMID: 30899112 DOI: 10.24875/aidsrev.19000003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The face of the HIV-1/AIDS pandemic has changed significantly thanks to the development of antiretroviral therapy (ART) regimens. Unfortunately, several HIV-associated comorbidities continuously occur in the clinical population, most notably HIV-associated neurocognitive disorders (HAND). While many molecular and cellular mechanisms have been characterized by describing HAND pathology (specifically neuroinflammatory insults and oxidative stress) in the ART era, compromised adult neurogenesis is emerging as a potential new mechanism. Neurogenesis is a dynamic process that generates new neurons and glial cells from neural stem cells (NSCs) and neural progenitor cells (NPCs) in specific areas of the brain. There are increasing observations that HIV-1 can productively and non-productively infect NSCs and NPCs. HIV-1 proteins and/or secondary immune/inflammatory responses impair the initial differentiation process of NSCs to NPCs, restrict neuronal lineage differentiation, and aberrantly promote astrocytic lineage differentiation. Recent studies with HIV-1 transgenic animal models demonstrate varying degrees of adult neurogenic deficits, which correlate with milder to moderate forms of neurocognitive impairments. The neurogenic dysfunction underlying HAND highlights the importance of developing potential therapeutics to restore adult neurogenic homeostasis in HIV-1 patients.
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Affiliation(s)
- Raj Putatunda
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania, USA
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
| | - Wen-Zhe Ho
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania, USA
| | - Wenhui Hu
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania, USA
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
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21
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Green MV, Thayer SA. HIV gp120 upregulates tonic inhibition through α5-containing GABA ARs. Neuropharmacology 2019; 149:161-168. [PMID: 30797029 DOI: 10.1016/j.neuropharm.2019.02.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/30/2018] [Accepted: 02/17/2019] [Indexed: 12/17/2022]
Abstract
HIV-Associated Neurocognitive disorder (HAND) affects nearly half of infected patients. The HIV envelope protein gp120 is shed by infected cells and is a potent neurotoxin in vitro that reproduces many aspects of HAND when expressed in vivo. Here, we show that HIV gp120 increases the amplitude of a tonic current mediated by γ-aminobutyric acid type-A receptors (GABAARs). Treating rat hippocampal cultures with 600 pM gp120IIIB for 4 h increased a tonic bicuculline-sensitive current, which remained elevated for 24 h. The increased current resulted from upregulation of extrasynaptic α5-containing GABAARs, as indicated by inhibition with the selective inverse agonist basmisanil. Treatment with gp120 increased α5-GABAAR immunoreactivity on the cell surface without new protein synthesis. The increase in tonic inhibition was prevented by a C-X-C chemokine receptor type 4 (CXCR4) antagonist or elimination of microglia from the culture. Treatment with interleukin-1β (IL-1β) increased the tonic current and an IL-1 receptor antagonist blocked the gp120-evoked response. Pharmacological or genetic inhibition of p38 mitogen-activated protein kinase (MAPK) prevented the gp120-evoked increase in tonic current and direct activation of a mutant form of p38 MAPK expressed in neurons increased the current. Collectively, these data show that gp120 activates CXCR4 to stimulate microglia to release IL-1β. Subsequent stimulation of IL-1 receptors activates p38 MAPK in neurons leading to the upregulation of α5-containing GABAARs. Increased tonic inhibition impairs neuroplasticity and inhibition of α5-containing GABAARs improves cognitive function in disease models. Thus, gp120-induced upregulation of α5-containing GABAARs presents a novel therapeutic target for HAND.
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Affiliation(s)
- Matthew V Green
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Stanley A Thayer
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN, 55455, USA; Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
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22
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Zhang X, Green MV, Thayer SA. HIV gp120-induced neuroinflammation potentiates NMDA receptors to overcome basal suppression of inhibitory synapses by p38 MAPK. J Neurochem 2019; 148:499-515. [PMID: 30520043 DOI: 10.1111/jnc.14640] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/21/2018] [Accepted: 11/27/2018] [Indexed: 12/18/2022]
Abstract
HIV-associated neurocognitive disorder affects about half of HIV-infected patients. HIV impairs neuronal function through indirect mechanisms mainly mediated by inflammatory cytokines and neurotoxic viral proteins, such as the envelope protein gp120. HIV gp120 elicits a neuroinflammatory response that potentiates NMDA receptor function and induces the loss of excitatory synapses. How gp120 influences neuronal inhibition remains unknown. In this study, we expressed a green fluorescent protein (GFP)-tagged recombinant antibody-like protein that binds to the post-synaptic scaffolding protein gephyrin to label inhibitory synapses in living neurons. Treatment with 600 pM gp120 for 24 h increased the number of labeled inhibitory synapses. HIV gp120 evoked the release of interleukin-1β (IL-1β) from microglia to activate IL-1 receptors on neurons. Subsequent activation of the tyrosine kinase Src and GluN2A-containing NMDA receptors increased the number of inhibitory synapses via a process that required protein synthesis. In naïve cultures, inhibition of neuronal p38 mitogen-activated protein kinase (p38 MAPK) increased the number of inhibitory synapses suggesting that p38 MAPK produces a basal suppression of inhibitory synapses that is overcome in the presence of gp120. Direct activation of a mutant form of p38 MAPK expressed in neurons mimicked basal suppression of inhibitory synapses. This study shows for the first time that gp120-induced neuroinflammation increases the number of inhibitory synapses and that this increase overcomes a basal suppression of synaptic inhibition. Increased inhibition may be an adaptive mechanism enabling neurons to counteract excess excitatory input in order to maintain network homeostasis. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Xinwen Zhang
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Matthew V Green
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Stanley A Thayer
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA.,Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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