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Davis SE, Cirincione AB, Jimenez-Torres AC, Zhu J. The Impact of Neurotransmitters on the Neurobiology of Neurodegenerative Diseases. Int J Mol Sci 2023; 24:15340. [PMID: 37895020 PMCID: PMC10607327 DOI: 10.3390/ijms242015340] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Neurodegenerative diseases affect millions of people worldwide. Neurodegenerative diseases result from progressive damage to nerve cells in the brain or peripheral nervous system connections that are essential for cognition, coordination, strength, sensation, and mobility. Dysfunction of these brain and nerve functions is associated with Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, and motor neuron disease. In addition to these, 50% of people living with HIV develop a spectrum of cognitive, motor, and/or mood problems collectively referred to as HIV-Associated Neurocognitive Disorders (HAND) despite the widespread use of a combination of antiretroviral therapies. Neuroinflammation and neurotransmitter systems have a pathological correlation and play a critical role in developing neurodegenerative diseases. Each of these diseases has a unique pattern of dysregulation of the neurotransmitter system, which has been attributed to different forms of cell-specific neuronal loss. In this review, we will focus on a discussion of the regulation of dopaminergic and cholinergic systems, which are more commonly disturbed in neurodegenerative disorders. Additionally, we will provide evidence for the hypothesis that disturbances in neurotransmission contribute to the neuronal loss observed in neurodegenerative disorders. Further, we will highlight the critical role of dopamine as a mediator of neuronal injury and loss in the context of NeuroHIV. This review will highlight the need to further investigate neurotransmission systems for their role in the etiology of neurodegenerative disorders.
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Affiliation(s)
| | | | | | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA; (S.E.D.); (A.B.C.); (A.C.J.-T.)
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2
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Pla-Tenorio J, Roig AM, García-Cesaní PA, Santiago LA, Sepulveda-Orengo MT, Noel RJ. Astrocytes: Role in pathogenesis and effect of commonly misused drugs in the HIV infected brain. CURRENT RESEARCH IN NEUROBIOLOGY 2023; 5:100108. [PMID: 38020814 PMCID: PMC10663134 DOI: 10.1016/j.crneur.2023.100108] [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: 09/21/2022] [Revised: 06/05/2023] [Accepted: 08/18/2023] [Indexed: 12/01/2023] Open
Abstract
The roles of astrocytes as reservoirs and producers of a subset of viral proteins in the HIV infected brain have been studied extensively as a key to understanding HIV-associated neurocognitive disorders (HAND). However, their comprehensive role in the context of intersecting substance use and neurocircuitry of the reward pathway and HAND has yet to be fully explained. Use of methamphetamines, cocaine, or opioids in the context of HIV infection have been shown to lead to a faster progression of HAND. Glutamatergic, dopaminergic, and GABAergic systems are implicated in the development of HAND-induced cognitive impairments. A thorough review of scientific literature exploring the variety of mechanisms in which these drugs exert their effects on the HIV brain and astrocytes has revealed marked areas of convergence in overexcitation leading to increased drug-seeking behavior, inflammation, apoptosis, and irreversible neurotoxicity. The present review investigates astrocytes, the neural pathways, and mechanisms of drug disruption that ultimately play a larger holistic role in terms of HIV progression and drug use. There are opportunities for future research, therapeutic intervention, and preventive strategies to diminish HAND in the subset population of patients with HIV and substance use disorder.
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Affiliation(s)
- Jessalyn Pla-Tenorio
- Ponce Health Sciences University, School of Medicine, Department of Basic Sciences, 395 Industrial Reparada, Zona 2, Ponce, PR, 00716, Puerto Rico
| | - Angela M. Roig
- Seattle Children's Hospital, MS OC.7.830, 4800 Sand Point Way NE, Seattle, WA, 98105-0371, United States
| | - Paulina A. García-Cesaní
- Bella Vista Hospital, Family Medicine Residency, Carr. 349 Km 2.7, Cerro Las Mesas, Mayaguez, PR, 00681, Puerto Rico
| | - Luis A. Santiago
- Ponce Health Sciences University, School of Medicine, Department of Basic Sciences, 395 Industrial Reparada, Zona 2, Ponce, PR, 00716, Puerto Rico
| | - Marian T. Sepulveda-Orengo
- Ponce Health Sciences University, School of Medicine, Department of Basic Sciences, 395 Industrial Reparada, Zona 2, Ponce, PR, 00716, Puerto Rico
| | - Richard J. Noel
- Ponce Health Sciences University, School of Medicine, Department of Basic Sciences, 395 Industrial Reparada, Zona 2, Ponce, PR, 00716, Puerto Rico
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Shao H, Li S. A new perspective on HIV: effects of HIV on brain-heart axis. Front Cardiovasc Med 2023; 10:1226782. [PMID: 37600062 PMCID: PMC10436320 DOI: 10.3389/fcvm.2023.1226782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/25/2023] [Indexed: 08/22/2023] Open
Abstract
The human immunodeficiency virus (HIV) infection can cause damage to multiple systems within the body, and the interaction among these various organ systems means that pathological changes in one system can have repercussions on the functions of other systems. However, the current focus of treatment and research on HIV predominantly centers around individual systems without considering the comprehensive relationship among them. The central nervous system (CNS) and cardiovascular system play crucial roles in supporting human life, and their functions are closely intertwined. In this review, we examine the effects of HIV on the CNS, the resulting impact on the cardiovascular system, and the direct damage caused by HIV to the cardiovascular system to provide new perspectives on HIV treatment.
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Affiliation(s)
| | - Sijun Li
- Department of Internal Medicine, The Fourth People's Hospital of Nanning, Nanning, China
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4
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Rodriguez MT, McLaurin KA, Shtutman M, Kubinak JL, Mactutus CF, Booze RM. Therapeutically targeting the consequences of HIV-1-associated gastrointestinal dysbiosis: Implications for neurocognitive and affective alterations. Pharmacol Biochem Behav 2023; 229:173592. [PMID: 37390973 PMCID: PMC10494709 DOI: 10.1016/j.pbb.2023.173592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 06/16/2023] [Accepted: 06/26/2023] [Indexed: 07/02/2023]
Abstract
Approximately 50 % of the individuals living with human immunodeficiency virus type 1 (HIV-1) are plagued by debilitating neurocognitive impairments (NCI) and/or affective alterations. Sizeable alterations in the composition of the gut microbiome, or gastrointestinal dysbiosis, may underlie, at least in part, the NCI, apathy, and/or depression observed in this population. Herein, two interrelated aims will be critically addressed, including: 1) the evidence for, and functional implications of, gastrointestinal microbiome dysbiosis in HIV-1 seropositive individuals; and 2) the potential for therapeutically targeting the consequences of this dysbiosis for the treatment of HIV-1-associated NCI and affective alterations. First, gastrointestinal microbiome dysbiosis in HIV-1 seropositive individuals is characterized by decreased alpha (α) diversity, a decreased relative abundance of bacterial species belonging to the Bacteroidetes phylum, and geographic-specific alterations in Bacillota (formerly Firmicutes) spp. Fundamentally, changes in the relative abundance of Bacteroidetes and Bacillota spp. may underlie, at least in part, the deficits in γ-aminobutyric acid and serotonin neurotransmission, as well as prominent synaptodendritic dysfunction, observed in this population. Second, there is compelling evidence for the therapeutic utility of targeting synaptodendritic dysfunction as a method to enhance neurocognitive function and improve motivational dysregulation in HIV-1. Further research is needed to determine whether the therapeutics enhancing synaptic efficacy exert their effects by altering the gut microbiome. Taken together, understanding gastrointestinal microbiome dysbiosis resulting from chronic HIV-1 viral protein exposure may afford insight into the mechanisms underlying HIV-1-associated neurocognitive and/or affective alterations; mechanisms which can be subsequently targeted via novel therapeutics.
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Affiliation(s)
- Mason T Rodriguez
- Cognitive and Neural Science Program, Department of Psychology, Barnwell College, 1512 Pendleton Street, University of South Carolina, Columbia, SC 29208, United States of America
| | - Kristen A McLaurin
- Cognitive and Neural Science Program, Department of Psychology, Barnwell College, 1512 Pendleton Street, University of South Carolina, Columbia, SC 29208, United States of America
| | - Michael Shtutman
- Drug Discovery and Biomedical Sciences, College of Pharmacy, 715 Sumter Street, University of South Carolina, Columbia, SC 29208, United States of America
| | - Jason L Kubinak
- Pathology, Microbiology & Immunology, School of Medicine Columbia, 6311 Garners Ferry Road, Building 2, Columbia, SC 29209, United States of America
| | - Charles F Mactutus
- Cognitive and Neural Science Program, Department of Psychology, Barnwell College, 1512 Pendleton Street, University of South Carolina, Columbia, SC 29208, United States of America
| | - Rosemarie M Booze
- Cognitive and Neural Science Program, Department of Psychology, Barnwell College, 1512 Pendleton Street, University of South Carolina, Columbia, SC 29208, United States of America.
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5
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Arjona SP, Allen CNS, Santerre M, Gross S, Soboloff J, Booze R, Sawaya BE. Disruption of Mitochondrial-associated ER membranes by HIV-1 tat protein contributes to premature brain aging. CNS Neurosci Ther 2022; 29:365-377. [PMID: 36419337 PMCID: PMC9804058 DOI: 10.1111/cns.14011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/04/2022] [Accepted: 10/19/2022] [Indexed: 11/27/2022] Open
Abstract
INTRODUCTION Mitochondrial-associated ER membranes (MAMs) control many cellular functions, including calcium and lipid exchange, intracellular trafficking, and mitochondrial biogenesis. The disruption of these functions contributes to neurocognitive disorders, such as spatial memory impairment and premature brain aging. Using neuronal cells, we demonstrated that HIV-1 Tat protein deregulates the mitochondria. METHODS& RESULTS To determine the mechanisms, we used a neuronal cell line and showed that Tat-induced changes in expression and interactions of both MAM-associated proteins and MAM tethering proteins. The addition of HIV-1 Tat protein alters expression levels of PTPIP51 and VAPB proteins in the MAM fraction but not the whole cell. Phosphorylation of PTPIP51 protein regulates its subcellular localization and function. We demonstrated that the Tat protein promotes PTPIP51 phosphorylation on tyrosine residues and prevents its binding to VAPB. Treatment of the cells with a kinase inhibitor restores the PTPIP51-VAPB interaction and overcomes the effect of Tat. CONCLUSION These results suggest that Tat disrupts the MAM, through the induction of PTPIP51 phosphorylation, leading to ROS accumulation, mitochondrial stress, and altered movement. Hence, we concluded that interfering in the MAM-associated cellular pathways contributes to spatial memory impairment and premature brain aging often observed in HIV-1-infected patients.
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Affiliation(s)
- Sterling P. Arjona
- Molecular Studies of Neurodegenerative Diseases Lab, Fels Cancer Institute for Personalized Medicine, Lewis Katz School of MedicineTemple UniversityPhiladelphiaPennsylvaniaUSA
| | - Charles N. S. Allen
- Molecular Studies of Neurodegenerative Diseases Lab, Fels Cancer Institute for Personalized Medicine, Lewis Katz School of MedicineTemple UniversityPhiladelphiaPennsylvaniaUSA
| | - Maryline Santerre
- Molecular Studies of Neurodegenerative Diseases Lab, Fels Cancer Institute for Personalized Medicine, Lewis Katz School of MedicineTemple UniversityPhiladelphiaPennsylvaniaUSA
| | - Scott Gross
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of MedicineTemple UniversityPhiladelphiaPennsylvaniaUSA
| | - Jonathan Soboloff
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of MedicineTemple UniversityPhiladelphiaPennsylvaniaUSA
| | - Rosemarie Booze
- Program of Behavioral Neuroscience, Department of PsychologyUniversity of South CarolinaColumbiaSouth CarolinaUSA
| | - Bassel E. Sawaya
- Molecular Studies of Neurodegenerative Diseases Lab, Fels Cancer Institute for Personalized Medicine, Lewis Katz School of MedicineTemple UniversityPhiladelphiaPennsylvaniaUSA,Department of Cancer and Cellular BiologyLewis Katz School of Medicine, Temple UniversityPhiladelphiaPennsylvaniaUSA,Department of Neural SciencesLewis Katz School of Medicine, Temple UniversityPhiladelphiaPennsylvaniaUSA
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6
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Xu C, Yadav-Samudrala BJ, Xu C, Nath B, Mistry T, Jiang W, Niphakis MJ, Cravatt BF, Mukhopadhyay S, Lichtman AH, Ignatowska-Jankowska BM, Fitting S. Inhibitory Neurotransmission Is Sex-Dependently Affected by Tat Expression in Transgenic Mice and Suppressed by the Fatty Acid Amide Hydrolase Enzyme Inhibitor PF3845 via Cannabinoid Type-1 Receptor Mechanisms. Cells 2022; 11:857. [PMID: 35269478 PMCID: PMC8909692 DOI: 10.3390/cells11050857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/14/2022] [Accepted: 02/23/2022] [Indexed: 11/21/2022] Open
Abstract
(1) Background. The endocannabinoid (eCB) system, which regulates physiological and cognitive processes, presents a promising therapeutic target for treating HIV-associated neurocognitive disorders (HAND). Here we examine whether upregulating eCB tone has potential protective effects against HIV-1 Tat (a key HIV transactivator of transcription) protein-induced alterations in synaptic activity. (2) Methods. Whole-cell patch-clamp recordings were performed to assess inhibitory GABAergic neurotransmission in prefrontal cortex slices of Tat transgenic male and female mice, in the presence and absence of the fatty acid amide hydrolase (FAAH) enzyme inhibitor PF3845. Western blot and mass spectrometry analyses assessed alterations of cannabinoid receptor and enzyme protein expression as well as endogenous ligands, respectively, to determine the impact of Tat exposure on the eCB system. (3) Results. GABAergic activity was significantly altered upon Tat exposure based on sex, whereas the effectiveness of PF3845 to suppress GABAergic activity in Tat transgenic mice was not altered by Tat or sex and involved CB1R-related mechanisms that depended on calcium signaling. Additionally, our data indicated sex-dependent changes for AEA and related non-eCB lipids based on Tat induction. (4) Conclusion. Results highlight sex- and/or Tat-dependent alterations of GABAergic activity and eCB signaling in the prefrontal cortex of Tat transgenic mice and further increase our understanding about the role of FAAH inhibition in neuroHIV.
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Affiliation(s)
- Changqing Xu
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (C.X.); (B.J.Y.-S.); (C.X.)
| | - Barkha J. Yadav-Samudrala
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (C.X.); (B.J.Y.-S.); (C.X.)
| | - Callie Xu
- Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (C.X.); (B.J.Y.-S.); (C.X.)
| | - Bhupendra Nath
- Department of Chemistry & Biochemistry, North Carolina Central University, Durham, NC 27707, USA; (B.N.); (T.M.); (S.M.)
| | - Twisha Mistry
- Department of Chemistry & Biochemistry, North Carolina Central University, Durham, NC 27707, USA; (B.N.); (T.M.); (S.M.)
| | - 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
- Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA 92037, USA; (M.J.N.); (B.F.C.)
| | - Benjamin F. Cravatt
- Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA 92037, USA; (M.J.N.); (B.F.C.)
| | - Somnath Mukhopadhyay
- Department of Chemistry & Biochemistry, North Carolina Central University, Durham, NC 27707, USA; (B.N.); (T.M.); (S.M.)
| | - 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; (C.X.); (B.J.Y.-S.); (C.X.)
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7
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Hall SA, Bell RP, Davis SW, Towe SL, Ikner TP, Meade CS. Human immunodeficiency virus-related decreases in corpus callosal integrity and corresponding increases in functional connectivity. Hum Brain Mapp 2021; 42:4958-4972. [PMID: 34382273 PMCID: PMC8449114 DOI: 10.1002/hbm.25592] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/25/2021] [Accepted: 07/06/2021] [Indexed: 12/15/2022] Open
Abstract
People living with human immunodeficiency virus (PLWH) often have neurocognitive impairment. However, findings on HIV-related differences in brain network function underlying these impairments are inconsistent. One principle frequently absent from these reports is that brain function is largely emergent from brain structure. PLWH commonly have degraded white matter; we hypothesized that functional communities connected by degraded white matter tracts would show abnormal functional connectivity. We measured white matter integrity in 69 PLWH and 67 controls using fractional anisotropy (FA) in 24 intracerebral white matter tracts. Then, among tracts with degraded FA, we identified gray matter regions connected to these tracts and measured their functional connectivity during rest. Finally, we identified cognitive impairment related to these structural and functional connectivity systems. We found HIV-related decreased FA in the corpus callosum body (CCb), which coordinates activity between the left and right hemispheres, and corresponding increases in functional connectivity. Finally, we found that individuals with impaired cognitive functioning have lower CCb FA and higher CCb functional connectivity. This result clarifies the functional relevance of the corpus callosum in HIV and provides a framework in which abnormal brain function can be understood in the context of abnormal brain structure, which may both contribute to cognitive impairment.
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Affiliation(s)
- Shana A. Hall
- Department of Psychiatry and Behavioral SciencesDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Ryan P. Bell
- Department of Psychiatry and Behavioral SciencesDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Simon W. Davis
- Department of NeurologyDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Sheri L. Towe
- Department of Psychiatry and Behavioral SciencesDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Taylor P. Ikner
- Department of Psychiatry and Behavioral SciencesDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Christina S. Meade
- Department of Psychiatry and Behavioral SciencesDuke University School of MedicineDurhamNorth CarolinaUSA
- Brain Imaging and Analysis CenterDuke University Medical CenterDurhamNorth CarolinaUSA
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8
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Confound, Cause, or Cure: The Effect of Cannabinoids on HIV-Associated Neurological Sequelae. Viruses 2021; 13:v13071242. [PMID: 34206839 PMCID: PMC8310358 DOI: 10.3390/v13071242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/12/2021] [Accepted: 06/15/2021] [Indexed: 12/15/2022] Open
Abstract
The persistence of human immunodeficiency virus-1 (HIV)-associated neurocognitive disorders (HAND) in the era of effective antiretroviral therapy suggests that modern HIV neuropathogenesis is driven, at least in part, by mechanisms distinct from the viral life cycle. Identifying more subtle mechanisms is complicated by frequent comorbidities in HIV+ populations. One of the common confounds is substance abuse, with cannabis being the most frequently used psychoactive substance among people living with HIV. The psychoactive effects of cannabis use can themselves mimic, and perhaps magnify, the cognitive deficits observed in HAND; however, the neuromodulatory and anti-inflammatory properties of cannabinoids may counter HIV-induced excitotoxicity and neuroinflammation. Here, we review our understanding of the cross talk between HIV and cannabinoids in the central nervous system by exploring both clinical observations and evidence from preclinical in vivo and in vitro models. Additionally, we comment on recent advances in human, multi-cell in vitro systems that allow for more translatable, mechanistic studies of the relationship between cannabinoid pharmacology and this uniquely human virus.
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9
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Olivero G, Vergassola M, Cisani F, Roggeri A, Pittaluga A. Presynaptic Release-regulating Metabotropic Glutamate Receptors: An Update. Curr Neuropharmacol 2021; 18:655-672. [PMID: 31775600 PMCID: PMC7457419 DOI: 10.2174/1570159x17666191127112339] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/15/2019] [Accepted: 11/22/2019] [Indexed: 12/18/2022] Open
Abstract
Metabotropic glutamate (mGlu) receptors represent the largest family of glutamate receptors in mammals and act as fine tuners of the chemical transmission in central nervous system (CNS). In the last decade, results concerning the expression and the subcellular localization of mGlu receptors further clarified their role in physio-pathological conditions. Concomitantly, their pharmacological characterization largely improved thanks to the identification of new compounds (chemical ligands and antibodies recognizing epitopic sequences of the receptor proteins) that allowed to decipher the protein compositions of the naive receptors. mGlu receptors are expressed at the presynaptic site of chemical synapses. Here, they modulate intraterminal enzymatic pathways controlling the migration and the fusion of vesicles to synaptic membranes as well as the phosphorylation of colocalized receptors. Both the control of transmitter exocytosis and the phosphorylation of colocalized receptors elicited by mGlu receptors are relevant events that dictate the plasticity of nerve terminals, and account for the main role of presynaptic mGlu receptors as modulators of neuronal signalling. The role of the presynaptic mGlu receptors in the CNS has been the matter of several studies and this review aims at briefly summarizing the recent observations obtained with isolated nerve endings (we refer to as synaptosomes). We focus on the pharmacological characterization of these receptors and on their receptor-receptor interaction / oligo-dimerization in nerve endings that could be relevant to the development of new therapeutic approaches for the cure of central pathologies.
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Affiliation(s)
| | | | | | | | - Anna Pittaluga
- Department of Pharmacy, University of Genoa, Genoa, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Policlinico San Martino, Genoa, Italy
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10
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Cirino TJ, McLaughlin JP. Mini review: Promotion of substance abuse in HIV patients: Biological mediation by HIV-1 Tat protein. Neurosci Lett 2021; 753:135877. [PMID: 33838257 DOI: 10.1016/j.neulet.2021.135877] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/28/2021] [Accepted: 03/30/2021] [Indexed: 11/29/2022]
Abstract
Despite successful viral suppression by combinatorial anti-retroviral therapy, HIV infection continues to negatively impact the quality of life of patients by promoting neuropathy and HIV-Associated Neurocognitive Disorders (HAND), where substance use disorder (SUD) is highly comorbid and known to worsen health outcomes. While substance abuse exacerbates the progression of HIV, emerging evidence also suggests the virus may potentiate the rewarding effect of abused substances. As HIV does not infect neurons, these effects are theorized to be mediated by viral proteins. Key among these proteins are HIV-1 Tat, which can continue to be produced under viral suppression in patients. This review will recap the behavioral evidence for HIV-1 Tat mediation of a potentiation of cocaine, opioid and alcohol reward, and explore the neurochemical dysfunction associated by Tat as potential mechanisms underlying changes in reward. Targeting rampant oxidative stress, inflammation and excitotoxicity associated with HIV and Tat protein exposure may prove useful in combating persistent substance abuse comorbid with HIV in the clinic.
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Affiliation(s)
- Thomas J Cirino
- Department of Neurology, School of Medicine, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Jay P McLaughlin
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA.
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11
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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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12
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Barbour AJ, Nass SR, Hahn YK, Hauser KF, Knapp PE. Restoration of KCC2 Membrane Localization in Striatal Dopamine D2 Receptor-Expressing Medium Spiny Neurons Rescues Locomotor Deficits in HIV Tat-Transgenic Mice. ASN Neuro 2021; 13:17590914211022089. [PMID: 34445881 PMCID: PMC8404672 DOI: 10.1177/17590914211022089] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 04/23/2021] [Accepted: 05/06/2021] [Indexed: 11/17/2022] Open
Abstract
People infected with HIV (PWH) are highly susceptible to striatal and hippocampal damage. Motor and memory impairments are common among these patients, likely as behavioral manifestations of damage to these brain regions. GABAergic dysfunction from HIV infection and viral proteins such as transactivator of transcription (Tat) have been well documented. We recently demonstrated that the neuron specific Cl- extruder, K+ Cl- cotransporter 2 (KCC2), is diminished after exposure to HIV proteins, including Tat, resulting in disrupted GABAAR-mediated hyperpolarization and inhibition. Here, we utilized doxycycline (DOX)-inducible, GFAP-driven HIV-1 Tat transgenic mice to further explore this phenomenon. After two weeks of Tat expression, we found no changes in hippocampal KCC2 levels, but a significant decrease in the striatum that was associated with hyperlocomotion in the open field assay. We were able to restore KCC2 activity and baseline locomotion with the KCC2 enhancer, CLP290. Additionally, we found that CLP290, whose mechanism of action has yet to be described, acts to restore phosphorylation of serine 940 resulting in increased KCC2 membrane localization. We also examined neuronal subpopulation contributions to the noted effects and found significant differences. Dopamine D2 receptor-expressing medium spiny neurons (MSNs) were selectively vulnerable to Tat-induced KCC2 loss, with no changes observed in dopamine D1 receptor-expressing MSNs. These results suggest that disinhibition/diminished hyperpolarization of dopamine D2 receptor-expressing MSNs can manifest as increased locomotion in this context. They further suggest that KCC2 activity might be a therapeutic target to alleviate motor disturbances related to HIV.
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Affiliation(s)
- Aaron J. Barbour
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
| | - Sara R. Nass
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
| | - Yun K. Hahn
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
| | - Kurt F. Hauser
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
| | - Pamela E. Knapp
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States
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13
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Benzodiazepine Use Is Associated With an Increased Risk of Neurocognitive Impairment in People Living With HIV. J Acquir Immune Defic Syndr 2020; 82:475-482. [PMID: 31714426 DOI: 10.1097/qai.0000000000002183] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Despite potential for dependence and adverse neurological effects, long-term benzodiazepine (BZD) use is common among people living with HIV (PLWH). As PLWH are at risk for central nervous system dysfunction, we retrospectively examined the association between BZD use and HIV-associated neurocognitive impairment (NCI). METHODS Three hundred six PLWH underwent comprehensive neurobehavioral evaluations. Current BZD use (BZD+) was determined through self-report. Using propensity scores, 153 BZD- individuals were matched to 153 BZD+ participants on demographics and medical comorbidities. Multiple regression models examined NCI and demographically adjusted neurocognitive T-scores as a function of BZD status, adjusting for estimated premorbid ability, current affective symptoms, and nadir CD4 count. Secondary analyses explored neurocognitive correlates of positive BZD urine toxicology screens (TOX+) and specific BZD agents. RESULTS Median duration of BZD use was 24 months. Current BZD use related to higher likelihood of NCI (odds ratio = 2.13, P = 0.003) and poorer global (d = -0.28, P = 0.020), processing speed (d = -0.23, P = 0.047), and motor T-scores (d = -0.32, P = 0.008). Compared with BZD-/TOX-, BZD+/TOX+ exhibited additional decrements in executive function (d = -0.48, P = 0.013), working memory (d = -0.49, P = 0.011), and delayed recall (d = -0.41, P = 0.032). For individual agents, diazepam, lorazepam, and alprazolam were most strongly associated with NCI (odds ratios >2.31). DISCUSSION BZD use may elevate risk for NCI in PLWH, potentially through diffuse neurocognitive slowing and acute compromise of recall and higher-order capacities. These effects are robust to psychosocial and HIV-specific factors and occur in comparison with a tightly matched BZD- group. Prospective and interventional studies should evaluate causal associations between NCI and BZD use and explore treatment alternatives to BZDs in PLWH.
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14
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Nass SR, Hahn YK, McLane VD, Varshneya NB, Damaj MI, Knapp PE, Hauser KF. Chronic HIV-1 Tat exposure alters anterior cingulate cortico-basal ganglia-thalamocortical synaptic circuitry, associated behavioral control, and immune regulation in male mice. Brain Behav Immun Health 2020; 5:100077. [PMID: 33083793 PMCID: PMC7571616 DOI: 10.1016/j.bbih.2020.100077] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 04/25/2020] [Indexed: 12/28/2022] Open
Abstract
HIV-1 selectively disrupts neuronal integrity within specific brain regions, reflecting differences in viral tropism and/or the regional differences in the vulnerability of distinct neuronal subpopulations within the CNS. Deficits in prefrontal cortex (PFC)-mediated executive function and the resultant loss of behavioral control are a particularly debilitating consequence of neuroHIV. To explore how HIV-1 disrupts executive function, we investigated the effects of 48 h, 2 and/or 8 weeks of HIV-1 Tat exposure on behavioral control, synaptic connectivity, and neuroimmune function in the anterior cingulate cortex (ACC) and associated cortico-basal ganglia (BG)-thalamocortical circuitry in adult, Tat transgenic male mice. HIV-1 Tat exposure increased novelty-exploration in response to novel food, flavor, and environmental stimuli, suggesting that Tat triggers increased novelty-exploration in situations of competing motivation (e.g., drive to feed or explore vs. fear of novel, brightly lit open areas). Furthermore, Tat induced adaptability in response to an environmental stressor and pre-attentive filtering deficits. The behavioral insufficiencies coincided with decreases in the inhibitory pre- and post-synaptic proteins, synaptotagmin 2 and gephyrin, respectively, in the ACC, and alterations in specific pro- and anti-inflammatory cytokines out of 23 assayed. The interaction of Tat exposure and the resultant time-dependent, selective alterations in CCL4, CXCL1, IL-12p40, and IL-17A levels in the PFC predicted significant decreases in adaptability. Tat decreased dendritic spine density and cortical VGLUT1 inputs, while increasing IL-1β, IL-6, CCL5, and CCL11 in the striatum. Alternatively, IL-1α, CCL5, and IL-13 were decreased in the mediodorsal thalamus despite the absence of synaptic changes. Thus, HIV-1 Tat appears to uniquely and systematically disrupt immune regulation and the inhibitory and excitatory synaptic balance throughout the ACC-BG-thalamocortical circuitry resulting in a loss of behavioral control.
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Affiliation(s)
- Sara R. Nass
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, Richmond, P.O. Box 980613, VA, 23298-0613, USA
| | - Yun K. Hahn
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, P.O. Box 980709, Richmond, VA, 23298-0709, USA
| | - Virginia D. McLane
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, Richmond, P.O. Box 980613, VA, 23298-0613, USA
| | - Neil B. Varshneya
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, Richmond, P.O. Box 980613, VA, 23298-0613, USA
| | - M. Imad Damaj
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, Richmond, P.O. Box 980613, VA, 23298-0613, USA
| | - Pamela E. Knapp
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, Richmond, P.O. Box 980613, VA, 23298-0613, USA
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, P.O. Box 980709, Richmond, VA, 23298-0709, USA
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, P.O. Box 980059, Richmond, VA, 23298-0059, USA
| | - Kurt F. Hauser
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, Richmond, P.O. Box 980613, VA, 23298-0613, USA
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, P.O. Box 980709, Richmond, VA, 23298-0709, USA
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, P.O. Box 980059, Richmond, VA, 23298-0059, USA
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15
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Cirino TJ, Harden SW, McLaughlin JP, Frazier CJ. Region-specific effects of HIV-1 Tat on intrinsic electrophysiological properties of pyramidal neurons in mouse prefrontal cortex and hippocampus. J Neurophysiol 2020; 123:1332-1341. [PMID: 32101482 DOI: 10.1152/jn.00029.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Human immunodeficiency virus (HIV)-1 transactivator of transcription protein (Tat) is a viral protein that promotes transcription of the HIV genome and possesses cell-signaling properties. Long-term exposure of central nervous system (CNS) tissue to HIV-1 Tat is theorized to contribute to HIV-associated neurodegenerative disorder (HAND). In the current study, we sought to directly evaluate the effect of HIV-1 Tat expression on the intrinsic electrophysiological properties of pyramidal neurons located in layer 2/3 of the medial prefrontal cortex and in area CA1 of the hippocampus. Toward that end, we drove Tat expression with doxycycline (100 mg·kg-1·day-1 ip) in inducible Tat (iTat) transgenic mice for 7 days and then performed single-cell electrophysiological studies in acute tissue slices made through the prefrontal cortex and hippocampus. Control experiments were performed in doxycycline-treated G-tg mice, which retain the tetracycline-sensitive promoter but do not express Tat. Our results indicated that the predominant effects of HIV-1 Tat expression are excitatory in medial prefrontal cortical pyramidal neurons yet inhibitory in hippocampal pyramidal neurons. Notably, in these two populations, HIV-1 Tat expression produced differential effects on neuronal gain, membrane time constant, resting membrane potential, and rheobase. Similarly, we also observed distinct effects on action potential kinetics and afterhyperpolarization, as well as on the current-voltage relationship in subthreshold voltage ranges. Collectively, these data provide mechanistic evidence of complex and region-specific changes in neuronal physiology by which HIV-1 Tat protein may promote cognitive deficits associated with HAND.NEW & NOTEWORTHY We drove expression of human immunodeficiency virus (HIV)-1 transactivator of transcription protein (Tat) protein in inducible Tat (iTat) transgenic mice for 7 days and then examined the effects on the intrinsic electrophysiological properties of pyramidal neurons located in the medial prefrontal cortex (mPFC) and in the hippocampus. Our results reveal a variety of specific changes that promote increased intrinsic excitability of layer II/III mPFC pyramidal neurons and decreased intrinsic excitability of hippocampal CA1 pyramidal neurons, highlighting both cell type and region-specific effects.
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Affiliation(s)
- Thomas J Cirino
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida
| | - Scott W Harden
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida
| | - Jay P McLaughlin
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida
| | - Charles J Frazier
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida
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16
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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: 10] [Impact Index Per Article: 2.0] [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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17
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SIV-Mediated Synaptic Dysfunction Is Associated with an Increase in Synapsin Site 1 Phosphorylation and Impaired PP2A Activity. J Neurosci 2019; 39:7006-7018. [PMID: 31270156 DOI: 10.1523/jneurosci.0178-19.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 05/31/2019] [Accepted: 06/22/2019] [Indexed: 11/21/2022] Open
Abstract
Although the reduction of viral loads in people with HIV undergoing combination antiretroviral therapy has mitigated AIDS-related symptoms, the prevalence of neurological impairments has remained unchanged. HIV-associated CNS dysfunction includes impairments in memory, attention, memory processing, and retrieval. Here, we show a significant site-specific increase in the phosphorylation of Syn I serine 9, site 1, in the frontal cortex lysates and synaptosome preparations of male rhesus macaques infected with simian immunodeficiency virus (SIV) but not in uninfected or SIV-infected antiretroviral therapy animals. Furthermore, we found that a lower protein phosphatase 2A (PP2A) activity, a phosphatase responsible for Syn I (S9) dephosphorylation, is primarily associated with the higher S9 phosphorylation in the frontal cortex of SIV-infected macaques. Comparison of brain sections confirmed higher Syn I (S9) in the frontal cortex and greater coexpression of Syn I and PP2A A subunit, which was observed as perinuclear aggregates in the somata of the frontal cortex of SIV-infected macaques. Synaptosomes from SIV-infected animals were physiologically tested using a synaptic vesicle endocytosis assay and FM4-64 dye showing a significantly higher baseline depolarization levels in synaptosomes of SIV+-infected than uninfected control or antiretroviral therapy animals. A PP2A-activating FDA-approved drug, FTY720, decreased the higher synaptosome depolarization in SIV-infected animals. Our results suggest that an impaired distribution and lower activity of serine/threonine phosphatases in the context of HIV infection may cause an indirect effect on the phosphorylation levels of essential proteins involving in synaptic transmission, supporting the occurrence of specific impairments in the synaptic activity during SIV infection.SIGNIFICANCE STATEMENT Even with antiretroviral therapy, neurocognitive deficits, including impairments in attention, memory processing, and retrieval, are still major concerns in people living with HIV. Here, we used the rhesus macaque simian immunodeficiency virus model with and without antiretroviral therapy to study the dynamics of phosphorylation of key amino acid residues of synapsin I, which critically impacts synaptic vesicle function. We found a significant increase in synapsin I phosphorylation at serine 9, which was driven by dysfunction of serine/threonine protein phosphatase 2A in the nerve terminals. Our results suggest that an impaired distribution and lower activity of serine/threonine phosphatases in the context of HIV infection may cause an indirect effect on the phosphorylation levels of essential proteins involved in synaptic transmission.
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18
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Li J, Wang W, Tong P, Leung CK, Yang G, Li Z, Li N, Sun X, Han Y, Lu C, Kuang D, Dai J, Zeng X. Autophagy Induction by HIV-Tat and Methamphetamine in Primary Midbrain Neuronal Cells of Tree Shrews via the mTOR Signaling and ATG5/ATG7 Pathway. Front Neurosci 2018; 12:921. [PMID: 30574066 PMCID: PMC6291520 DOI: 10.3389/fnins.2018.00921] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/23/2018] [Indexed: 12/22/2022] Open
Abstract
Background: Addictive stimulant drugs, such as methamphetamine (METH), increase the risk of exposure to the human immunodeficiency virus-1 (HIV-1) infection and thus predispose individuals to the development of HIV-associated neurocognitive disorders (HANDs). Previous studies have indicated that HIV-Tat (the transactivator of transcription) and METH can synergistically induce autophagy in SH-SY5Y neuroblastoma cells and that autophagy plays a pivotal role in the neuronal dysfunction in HANDs. However, the underlying mechanism of METH-and HIV-Tat-induced neuronal autophagy remains unclear. Methods: We cultured primary midbrain neuronal cells of tree shrews and treated them with METH and HIV-Tat to study the role of METH and HIV-Tat in inducing autophagy. We evaluated the effects of the single or combined treatment of METH and HIV-Tat on the protein expressions of the autophagy-related genes, including Beclin-1 and LC3B, ATG5, and ATG7 in METH and HIV-Tat-induced autophagy. In addition, the presence of autophagosomes in the METH and/or HIV-Tat treatment was revealed using transmission electron microscopy. Results: The results indicated that METH increased the protein levels of LC3B and Beclin-1, and these effects were significantly enhanced by HIV-Tat. Moreover, the results suggested that ATG5 and ATG7 were involved in the METH and HIV-Tat-induced autophagy. In addition, it was found that mTOR inhibition via pharmacological intervention could trigger autophagy and promote METH and HIV-Tat-induced autophagy. Discussion: Overall, this study contributes to the knowledge of the molecular underpinnings of METH and HIV-Tat-induced autophagy in primary midbrain neuronal cells. Our findings may facilitate the development of therapeutic strategies for METH-and HIV-Tat-induced autophagy in HANDs.
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Affiliation(s)
- Juan Li
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China.,School of Basic Medicine, Kunming Medical University, Kunming, China
| | - Wenguang Wang
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China
| | - Pinfen Tong
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China
| | - Chi-Kwan Leung
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,Chinese University of Hong Kong - Shandong University (CUHK-SDU) Joint Laboratory of Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Genmeng Yang
- School of Forensic Medicine, Kunming Medical University, Kunming, China
| | - Zhen Li
- School of Forensic Medicine, Kunming Medical University, Kunming, China
| | - Na Li
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China
| | - Xiaomei Sun
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China
| | - Yuanyuan Han
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China
| | - Caixia Lu
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China
| | - Dexuan Kuang
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China
| | - Jiejie Dai
- Center of Tree Shrew Germplasm Resources, Institute of Medical Biology, The Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China
| | - Xiaofeng Zeng
- School of Forensic Medicine, Kunming Medical University, Kunming, China
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19
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Piekna-Przybylska D, Nagumotu K, Reid DM, Maggirwar SB. HIV-1 infection renders brain vascular pericytes susceptible to the extracellular glutamate. J Neurovirol 2018; 25:114-126. [PMID: 30402824 DOI: 10.1007/s13365-018-0693-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/28/2018] [Accepted: 10/25/2018] [Indexed: 12/18/2022]
Abstract
Reduced pericytes' coverage of endothelium in the brain is one of the structural changes leading to breach of the blood-brain barrier during HIV infection. We previously showed in central memory T (TCM) cells that HIV latency increases cellular susceptibility to DNA damage. In this study, we investigated susceptibility of primary brain pericytes infected with HIV-1 to DNA damage in response to glutamate and TNF-α, both known to induce neuronal death during chronic inflammatory conditions. To infect pericytes, we used a single-cycle HIV-1 pseudotyped with VSV-G envelope glycoprotein and maintained the cultures until latency was established. Our data indicate that pericytes silence HIV-1 expression at similar rate compared to primary TCM cells. TNF-α and IL-1β caused partial reactivation of the virus suggesting that progression of disease and neuroinflammation might facilitate virus reactivation from latency. Significant increases in the level of γH2AX, which reflect DNA damage, were observed in infected cultures exposed to TNF-α and glutamate at day 2 post-infection. Glutamate, an excitatory neurologic stimuli, also caused increases in the γH2AX level in latently infected pericytes, whereas PARP and DNA-PK inhibitors caused reductions in cell population suggesting that HIV-1 latency affects repairs of single- and double-strand DNA breaks. For comparison, we also analyzed latently infected astrocytes and determined that DNA damage response in astrocytes is less affected by HIV-1. In conclusion, our results indicate that productive infection and HIV-1 latency in pericytes interfere with DNA damage response, rendering them vulnerable to the agents that are characteristic of chronic neuroinflammatory disease conditions.
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Affiliation(s)
- Dorota Piekna-Przybylska
- Department of Microbiology and Immunology, School of Medicine and Dentistry, University of Rochester, Rochester, NY, 14642, USA.
| | - Kavyasri Nagumotu
- Department of Microbiology and Immunology, School of Medicine and Dentistry, University of Rochester, Rochester, NY, 14642, USA
| | - Danielle M Reid
- Department of Microbiology and Immunology, School of Medicine and Dentistry, University of Rochester, Rochester, NY, 14642, USA
| | - Sanjay B Maggirwar
- Department of Microbiology and Immunology, School of Medicine and Dentistry, University of Rochester, Rochester, NY, 14642, USA
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20
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Vergassola M, Olivero G, Cisani F, Usai C, Bossi S, Puliti A, Pittaluga A. Presynaptic mGlu1 Receptors Control GABA B Receptors in an Antagonist-Like Manner in Mouse Cortical GABAergic and Glutamatergic Nerve Endings. Front Mol Neurosci 2018; 11:324. [PMID: 30279647 PMCID: PMC6153310 DOI: 10.3389/fnmol.2018.00324] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/22/2018] [Indexed: 01/03/2023] Open
Abstract
Mouse cortical GABAergic synaptosomes possess presynaptic inhibitory GABAB autoreceptors. Accordingly, (±)baclofen (3 μM) inhibits in a CGP53423-sensitive manner the 12 mM KCl-evoked release of preloaded [3H]GABA. Differently, the existence of presynaptic release-regulating metabotropic glutamate type 1 (mGlu1) heteroreceptors in these terminals is still matter of discussion, although confocal microscopy unveiled the existence of mGlu1α with GABAB1 or GABAB2 proteins in cortical VGAT-positive synaptosomes. The group I mGlu agonist 3,5-DHPG failed to modify on its own the 12 mM KCl-evoked [3H]GABA exocytosis from cortical nerve endings, but, when added concomitantly to the GABAB agonist, it significantly reduced the 3 μM (±)baclofen-induced inhibition of [3H]GABA exocytosis. Conversely, the mGlu1 antagonist LY367385 (0.03–1 μM), inactive on its own on GABA exocytosis, amplified the 3 μM (±)baclofen-induced inhibition of [3H]GABA overflow. The ( ± )baclofen-induced inhibition of [3H]GABA exocytosis was more pronounced in cortical synaptosomes from Grm1crv4/crv4 mice, which bear a spontaneous mutation of the Grm1 gene leading to the functional inactivation of the mGlu1 receptor. Inasmuch, the expression of GABAB2 receptor protein in cortical synaptosomal lysates from Grm1crv4/crv4 mice was increased when compared to controls. Altogether, these observations seem best interpreted by assuming that mGlu1 coexist with GABAB receptors in GABAergic cortical synaptosomes, where they control GABA receptors in an antagonist-like manner. We then asked whether the mGlu1-mediated control of GABAB receptors is restricted to GABAergic terminals, or if it occurs also in other subpopulations of nerve endings. Release-regulating GABAB receptors also exist in glutamatergic nerve endings. (±)baclofen (1 μM) diminished the 12 mM KCl-evoked [3H]D-aspartate overflow. Also in these terminals, the concomitant presence of 1 μM LY367385, inactive on its own, significantly amplified the inhibitory effect exerted by (±)baclofen on [3H]D-aspartate exocytosis. Confocal microscopy confirmed the colocalization of mGlu1 with GABAB1 and GABAB2 labeling in vesicular glutamate type1 transporter-positive particles. Our results support the conclusion that mGlu1 receptors modulate in an antagonist-like manner presynaptic release-regulating GABAB receptors. This receptor–receptor interaction could be neuroprotective in central disease typified by hyperglutamatergicity.
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Affiliation(s)
| | | | | | - Cesare Usai
- Institute of Biophysics, National Research Council, Genoa, Italy
| | - Simone Bossi
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Aldamaria Puliti
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,IRCCS Istituto Giannina Gaslini, Genoa, Italy.,Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, University of Genoa, Genoa, Italy.,Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
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21
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Mohseni Ahooyi T, Shekarabi M, Decoppet EA, Langford D, Khalili K, Gordon J. Network analysis of hippocampal neurons by microelectrode array in the presence of HIV-1 Tat and cocaine. J Cell Physiol 2018; 233:9299-9311. [PMID: 29206302 DOI: 10.1002/jcp.26322] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 11/27/2017] [Indexed: 12/18/2022]
Abstract
HIV-associated neurocognitive disorders affecting greater than 30% of patients are caused by HIV-1 infection of the CNS, and in part, include neurotoxic effects of the viral transactivator of transcription, Tat protein. In addition to increasing the risk for becoming HIV infected, cocaine abuse enhances the neuropathogenic impacts of HIV-1. To investigate the outcome of Tat and cocaine interference in the hippocampal neuronal network, cross-rank-corrlation was employed to develop a systematic framework to assess hippocampal neurons behavior cultured on multielectrode arrays. Tat and cocaine differentially disturbed neuronal spiking rates, amplitude, synchronous activity, and oscillations within the hippocampal neuronal network via potentiation of inhibitory neurotransmission. The Tat-mediated impairment of neuronal spiking was reversible by removal of Tat, which restored neuronal activity. The presence of astrocytes co-cultured with neuronal networks diminished the effects of Tat and cocaine on neuron function suggesting a role for astrocytes in stabilizing neuronal behavior and increasing neuronal spontaneous activities such as bursting amplitude, frequency, and wave propagation rate. Taken together, our studies indicate that the HIV protein Tat and cocaine impair hippocampal neuronal network functioning and that the presence of astrocytes alleviates network dysfunction pointing to a newly discovered pathway through which ionic homeostasis is maintained by neuron-glial crosstalk in the CNS.
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Affiliation(s)
- Taha Mohseni Ahooyi
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Masoud Shekarabi
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Emilie A Decoppet
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Dianne Langford
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Kamel Khalili
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Jennifer Gordon
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
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22
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Abstract
A defining feature of HIV-associated neurocognitive disorder (HAND) is the loss of excitatory synaptic connections. Synaptic changes that occur during exposure to HIV appear to result, in part, from a homeostatic scaling response. Here we discuss the mechanisms of these changes from the perspective that they might be part of a coping mechanism that reduces synapses to prevent excitotoxicity. In transgenic animals expressing the HIV proteins Tat or gp120, the loss of synaptic markers precedes changes in neuronal number. In vitro studies have shown that HIV-induced synapse loss and cell death are mediated by distinct mechanisms. Both in vitro and animal studies suggest that HIV-induced synaptic scaling engages new mechanisms that suppress network connectivity and that these processes might be amenable to therapeutic intervention. Indeed, pharmacological reversal of synapse loss induced by HIV Tat restores cognitive function. In summary, studies indicate that there are temporal, mechanistic and pharmacological features of HIV-induced synapse loss that are consistent with homeostatic plasticity. The increasingly well delineated signaling mechanisms that regulate synaptic scaling may reveal pharmacological targets suitable for normalizing synaptic function in chronic neuroinflammatory states such as HAND.
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Affiliation(s)
- Matthew V Green
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Jonathan D Raybuck
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Xinwen Zhang
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Mariah M Wu
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Stanley A Thayer
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
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23
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Bonfiglio T, Olivero G, Vergassola M, Di Cesare Mannelli L, Pacini A, Iannuzzi F, Summa M, Bertorelli R, Feligioni M, Ghelardini C, Pittaluga A. Environmental training is beneficial to clinical symptoms and cortical presynaptic defects in mice suffering from experimental autoimmune encephalomyelitis. Neuropharmacology 2018; 145:75-86. [PMID: 29402503 DOI: 10.1016/j.neuropharm.2018.01.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 01/19/2018] [Accepted: 01/20/2018] [Indexed: 01/08/2023]
Abstract
The effect of "prophylactic" environmental stimulation on clinical symptoms and presynaptic defects in mice suffering from the experimental autoimmune encephalomyelitis (EAE) at the acute stage of disease (21 ± 1 days post immunization, d.p.i.) was investigated. In EAE mice raised in an enriched environment (EE), the clinical score was reduced when compared to EAE mice raised in standard environment (SE).Concomitantly, gain of weight and increased spontaneous motor activity and curiosity were observed, suggesting increased well-being in mice. Impaired glutamate exocytosis and cyclic adenosine monophosphate (cAMP) production in cortical terminals of SE-EAE mice were evident at 21 ± 1 d.p.i.. Differently, the 12 mM KCl-evoked glutamate exocytosis from cortical synaptosomes of EE-EAE mice was comparable to that observed in SE and EE-control mice, but significantly higher than that in SE-EAE mice. Similarly, the 12 mM KCl-evoked cAMP production in EE-EAE mice cortical synaptosomes recovered to the level observed in SE and EE-control mice. MUNC-18 and SNAP25 contents, but not Syntaxin-1a and Synaptotagmin 1 levels, were increased in cortical synaptosomes from EE-EAE mice when compared to SE-EAE mice. Circulating IL-1β was increased in the spinal cord, but not in the cortex, of SE-EAE mice, and it did not recover in EE-EAE mice. Inflammatory infiltrates were reduced in the cortex but not in the spinal cord of EE-EAE mice. Demyelination was observed in the spinal cord; EE significantly diminished it. We conclude that "prophylactic" EE is beneficial to synaptic derangements and preserves glutamate transmission in the cortex of EAE mice. This article is part of the Special Issue entitled "Neurobiology of Environmental Enrichment".
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Affiliation(s)
- T Bonfiglio
- Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - G Olivero
- Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - M Vergassola
- Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - L Di Cesare Mannelli
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, Italy
| | - A Pacini
- Department of Experimental and Clinical Medicine, DMSC, Section of Anatomy and Histology, University of Florence, Italy
| | - F Iannuzzi
- EBRI-European Brain Research Institute, Rome, Italy
| | - M Summa
- D3. PharmaChemistry Line, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
| | - R Bertorelli
- D3. PharmaChemistry Line, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
| | - M Feligioni
- EBRI-European Brain Research Institute, Rome, Italy; Department of Neurorehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | - C Ghelardini
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, Italy
| | - A Pittaluga
- Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy; Centre of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy.
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24
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Bossi S, Musante I, Bonfiglio T, Bonifacino T, Emionite L, Cerminara M, Cervetto C, Marcoli M, Bonanno G, Ravazzolo R, Pittaluga A, Puliti A. Genetic inactivation of mGlu5 receptor improves motor coordination in the Grm1 crv4 mouse model of SCAR13 ataxia. Neurobiol Dis 2017; 109:44-53. [PMID: 28982591 DOI: 10.1016/j.nbd.2017.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/13/2017] [Accepted: 10/01/2017] [Indexed: 01/29/2023] Open
Abstract
Deleterious mutations in the glutamate receptor metabotropic 1 gene (GRM1) cause a recessive form of cerebellar ataxia, SCAR13. GRM1 and GRM5 code for the metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, respectively. Their different expression profiles suggest they could have distinct functional roles. In a previous study, homozygous mice lacking mGlu1 receptors (Grm1crv4/crv4) and exhibiting ataxia presented cerebellar overexpression of mGlu5 receptors, that was proposed to contribute to the mouse phenotype. To test this hypothesis, we here crossed Grm1crv4 and Grm5ko mice to generate double mutants (Grm1crv4/crv4Grm5ko/ko) lacking both mGlu1 and mGlu5 receptors. Double mutants and control mice were analyzed for spontaneous behavior and for motor activity by rotarod and footprint analyses. In the same mice, the release of glutamate from cerebellar nerve endings (synaptosomes) elicited by 12mM KCl or by α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) was also evaluated. Motor coordination resulted improved in double mutants when compared to Grm1crv4/crv4 mice. Furthermore, in in vitro studies, glutamate release elicited by both KCl depolarization and activation of AMPA autoreceptors resulted reduced in Grm1crv4/crv4 mice compared to wild type mice, while it presented normal levels in double mutants. Moreover, we found that Grm1crv4/crv4 mice showed reduced expression of GluA2/3 AMPA receptor subunits in cerebellar synaptosomes, while it resulted restored to wild type level in double mutants. To conclude, blocking of mGlu5 receptor reduced the dysregulation of glutamate transmission and improved motor coordination in the Grm1crv4 mouse model of SCAR13, thus suggesting the possible usefulness of pharmacological therapies based on modulation of mGlu5 receptor activity for the treatment of this type of ataxia.
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Affiliation(s)
- Simone Bossi
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy
| | - Ilaria Musante
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy
| | - Tommaso Bonfiglio
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy
| | - Tiziana Bonifacino
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy
| | - Laura Emionite
- Animal Facility, IRCCS A.U.O. San Martino-IST, Largo Rosanna Benzi 10, Genoa, Italy
| | - Maria Cerminara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy
| | - Chiara Cervetto
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy
| | - Manuela Marcoli
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy
| | - Giambattista Bonanno
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy
| | - Roberto Ravazzolo
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy; Medical Genetics Unit, Istituto Giannina Gaslini, via Gaslini 5, 16148 Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy
| | - Aldamaria Puliti
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy; Medical Genetics Unit, Istituto Giannina Gaslini, via Gaslini 5, 16148 Genoa, Italy.
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25
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Gaskill PJ, Miller DR, Gamble-George J, Yano H, Khoshbouei H. HIV, Tat and dopamine transmission. Neurobiol Dis 2017; 105:51-73. [PMID: 28457951 PMCID: PMC5541386 DOI: 10.1016/j.nbd.2017.04.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/04/2017] [Accepted: 04/16/2017] [Indexed: 01/02/2023] Open
Abstract
Human Immunodeficiency Virus (HIV) is a progressive infection that targets the immune system, affecting more than 37 million people around the world. While combinatorial antiretroviral therapy (cART) has lowered mortality rates and improved quality of life in infected individuals, the prevalence of HIV associated neurocognitive disorders is increasing and HIV associated cognitive decline remains prevalent. Recent research has suggested that HIV accessory proteins may be involved in this decline, and several studies have indicated that the HIV protein transactivator of transcription (Tat) can disrupt normal neuronal and glial function. Specifically, data indicate that Tat may directly impact dopaminergic neurotransmission, by modulating the function of the dopamine transporter and specifically damaging dopamine-rich regions of the CNS. HIV infection of the CNS has long been associated with dopaminergic dysfunction, but the mechanisms remain undefined. The specific effect(s) of Tat on dopaminergic neurotransmission may be, at least partially, a mechanism by which HIV infection directly or indirectly induces dopaminergic dysfunction. Therefore, precisely defining the specific effects of Tat on the dopaminergic system will help to elucidate the mechanisms by which HIV infection of the CNS induces neuropsychiatric, neurocognitive and neurological disorders that involve dopaminergic neurotransmission. Further, this will provide a discussion of the experiments needed to further these investigations, and may help to identify or develop new therapeutic approaches for the prevention or treatment of these disorders in HIV-infected individuals.
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Affiliation(s)
- Peter J Gaskill
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, United States.
| | - Douglas R Miller
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, United States
| | - Joyonna Gamble-George
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, United States
| | - Hideaki Yano
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, United States
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, United States.
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26
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Chang L, Lim A, Lau E, Alicata D. Chronic Tobacco-Smoking on Psychopathological Symptoms, Impulsivity and Cognitive Deficits in HIV-Infected Individuals. J Neuroimmune Pharmacol 2017; 12:389-401. [PMID: 28303534 PMCID: PMC5529218 DOI: 10.1007/s11481-017-9728-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/09/2017] [Indexed: 12/21/2022]
Abstract
HIV-infected individuals (HIV+) has 2-3 times the rate of tobacco smoking than the general population, and whether smoking may lead to greater psychiatric symptoms or cognitive deficits remains unclear. We evaluated the independent and combined effects of being HIV+ and chronic tobacco-smoking on impulsivity, psychopathological symptoms and cognition. 104 participants [27 seronegative (SN)-non-Smokers, 26 SN-Smokers, 29 HIV+ non-Smokers, 22 HIV+ Smokers] were assessed for psychopathology symptoms (Symptom Checklist-90, SCL-90), depressive symptoms (Center for Epidemiologic Studies-Depression Scale, CES-D), impulsivity (Barratt Impulsiveness Scale, BIS), decision-making (The Iowa Gambling Task, IGT, and Wisconsin Card Sorting Test, WCST), and cognition (seven neurocognitive domains). Both HIV+ and Smoker groups had higher SCL-90 and CES-D scores, with highest scores in HIV+ Smokers. On BIS, both HIV+ and Smokers had higher Total Impulsiveness scores, with higher behavioral impulsivity in Smokers, highest in HIV+ Smokers. Furthermore, across the four groups, HIV+ Smokers lost most money and made fewest advantageous choices on the IGT, and had highest percent errors on WCST. Lastly, HIV+ had lower z-scores on all cognitive domains, with the lowest scores in HIV+ Smokers. These findings suggest that HIV-infection and chronic tobacco smoking may lead to additive deleterious effects on impulsivity, psychopathological (especially depressive) symptoms and cognitive dysfunction. Although greater impulsivity may be premorbid in HIV+ and Smokers, the lack of benefits of nicotine in chronic Smokers on attention and psychopathology, especially those with HIV-infection, may be due to the negative effects of chronic smoking on dopaminergic and cardio-neurovascular systems. Tobacco smoking may contribute to psychopathology and neurocognitive disorders in HIV+ individuals.
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Affiliation(s)
- Linda Chang
- Neuroscience & MR Research Program, Department of Medicine, John A. Burns School of Medicine, University of Hawaii and Queen's Medical Center, 1356 Lusitana Street, 7th Floor, Honolulu, HI, 96813, USA.
| | - Ahnate Lim
- Neuroscience & MR Research Program, Department of Medicine, John A. Burns School of Medicine, University of Hawaii and Queen's Medical Center, 1356 Lusitana Street, 7th Floor, Honolulu, HI, 96813, USA
| | - Eric Lau
- Neuroscience & MR Research Program, Department of Medicine, John A. Burns School of Medicine, University of Hawaii and Queen's Medical Center, 1356 Lusitana Street, 7th Floor, Honolulu, HI, 96813, USA
| | - Daniel Alicata
- Neuroscience & MR Research Program, Department of Medicine, John A. Burns School of Medicine, University of Hawaii and Queen's Medical Center, 1356 Lusitana Street, 7th Floor, Honolulu, HI, 96813, USA
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27
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Nedelcovych MT, Tenora L, Kim BH, Kelschenbach J, Chao W, Hadas E, Jančařík A, Prchalová E, Zimmermann SC, Dash RP, Gadiano AJ, Garrett C, Furtmüller G, Oh B, Brandacher G, Alt J, Majer P, Volsky DJ, Rais R, Slusher BS. N-(Pivaloyloxy)alkoxy-carbonyl Prodrugs of the Glutamine Antagonist 6-Diazo-5-oxo-l-norleucine (DON) as a Potential Treatment for HIV Associated Neurocognitive Disorders. J Med Chem 2017; 60:7186-7198. [PMID: 28759224 DOI: 10.1021/acs.jmedchem.7b00966] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Aberrant excitatory neurotransmission associated with overproduction of glutamate has been implicated in the development of HIV-associated neurocognitive disorders (HAND). The glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON, 14) attenuates glutamate synthesis in HIV-infected microglia/macrophages, offering therapeutic potential for HAND. We show that 14 prevents manifestation of spatial memory deficits in chimeric EcoHIV-infected mice, a model of HAND. 14 is not clinically available, however, because its development was hampered by peripheral toxicities. We describe the synthesis of several substituted N-(pivaloyloxy)alkoxy-carbonyl prodrugs of 14 designed to circulate inert in plasma and be taken up and biotransformed to 14 in the brain. The lead prodrug, isopropyl 6-diazo-5-oxo-2-(((phenyl(pivaloyloxy)methoxy)carbonyl)amino)hexanoate (13d), was stable in swine and human plasma but liberated 14 in swine brain homogenate. When dosed systemically in swine, 13d provided a 15-fold enhanced CSF-to-plasma ratio and a 9-fold enhanced brain-to-plasma ratio relative to 14, opening a possible clinical path for the treatment of HAND.
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Affiliation(s)
| | - Lukáš Tenora
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic vvi , 166 10 Prague, Czech Republic
| | - Boe-Hyun Kim
- Department of Medicine, Icahn School of Medicine at Mount Sinai , New York, New York 10029, United States
| | - Jennifer Kelschenbach
- Department of Medicine, Icahn School of Medicine at Mount Sinai , New York, New York 10029, United States
| | - Wei Chao
- Department of Medicine, Icahn School of Medicine at Mount Sinai , New York, New York 10029, United States
| | - Eran Hadas
- Department of Medicine, Icahn School of Medicine at Mount Sinai , New York, New York 10029, United States
| | - Andrej Jančařík
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic vvi , 166 10 Prague, Czech Republic
| | - Eva Prchalová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic vvi , 166 10 Prague, Czech Republic
| | | | | | | | | | | | | | | | | | - Pavel Majer
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic vvi , 166 10 Prague, Czech Republic
| | - David J Volsky
- Department of Medicine, Icahn School of Medicine at Mount Sinai , New York, New York 10029, United States
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28
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Nookala AR, Mitra J, Chaudhari NS, Hegde ML, Kumar A. An Overview of Human Immunodeficiency Virus Type 1-Associated Common Neurological Complications: Does Aging Pose a Challenge? J Alzheimers Dis 2017; 60:S169-S193. [PMID: 28800335 PMCID: PMC6152920 DOI: 10.3233/jad-170473] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With increasing survival of patients infected with human immunodeficiency virus type 1 (HIV-1), the manifestation of heterogeneous neurological complications is also increasing alarmingly in these patients. Currently, more than 30% of about 40 million HIV-1 infected people worldwide develop central nervous system (CNS)-associated dysfunction, including dementia, sensory, and motor neuropathy. Furthermore, the highly effective antiretroviral therapy has been shown to increase the prevalence of mild cognitive functions while reducing other HIV-1-associated neurological complications. On the contrary, the presence of neurological disorder frequently affects the outcome of conventional HIV-1 therapy. Although, both the children and adults suffer from the post-HIV treatment-associated cognitive impairment, adults, especially depending on the age of disease onset, are more prone to CNS dysfunction. Thus, addressing neurological complications in an HIV-1-infected patient is a delicate balance of several factors and requires characterization of the molecular signature of associated CNS disorders involving intricate cross-talk with HIV-1-derived neurotoxins and other cellular factors. In this review, we summarize some of the current data supporting both the direct and indirect mechanisms, including neuro-inflammation and genome instability in association with aging, leading to CNS dysfunction after HIV-1 infection, and discuss the potential strategies addressing the treatment or prevention of HIV-1-mediated neurotoxicity.
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Affiliation(s)
- Anantha Ram Nookala
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Joy Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Nitish S. Chaudhari
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Muralidhar L. Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
- Weill Cornell Medical College of Cornell University, NY, USA
| | - Anil Kumar
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA
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29
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Musante I, Mattinzoli D, Otescu LA, Bossi S, Ikehata M, Gentili C, Cangemi G, Gatti C, Emionite L, Messa P, Ravazzolo R, Rastaldi MP, Riccardi D, Puliti A. Phenotypic characterization of Grm1 crv4 mice reveals a functional role for the type 1 metabotropic glutamate receptor in bone mineralization. Bone 2017; 94:114-123. [PMID: 27989650 DOI: 10.1016/j.bone.2016.10.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 09/08/2016] [Accepted: 10/25/2016] [Indexed: 11/20/2022]
Abstract
Recent increasing evidence supports a role for neuronal type signaling in bone. Specifically glutamate receptors have been found in cells responsible for bone remodeling, namely the osteoblasts and the osteoclasts. While most studies have focused on ionotropic glutamate receptors, the relevance of the metabotropic glutamate signaling in bone is poorly understood. Specifically type 1 metabotropic glutamate (mGlu1) receptors are expressed in bone, but the effect of its ablation on skeletal development has never been investigated. Here we report that Grm1crv4/crv4 mice, homozygous for an inactivating mutation of the mGlu1 receptor, and mainly characterized by ataxia and renal dysfunction, exhibit decreased body weight, bone length and bone mineral density compared to wild type (WT) animals. Blood analyses of the affected mice demonstrate the absence of changes in circulating factors, such as vitamin D and PTH, suggesting renal damage is not the main culprit of the skeletal phenotype. Cultures of osteoblasts lacking functional mGlu1 receptors exhibit less homogeneous collagen deposition than WT cells, and present increased expression of osteocalcin, a marker of osteoblast maturation. These data suggest that the skeletal damage is directly linked to the absence of the receptor, which in turn leads to osteoblasts dysfunction and earlier maturation. Accordingly, skeletal histomorphology suggests that Grm1crv4/crv4 mice exhibit enhanced bone maturation, resulting in premature fusion of the growth plate and shortened long bones, and further slowdown of bone apposition rate compared to the WT animals. In summary, this work reveals novel functions of mGlu1 receptors in the bone and indicates that in osteoblasts mGlu1 receptors are necessary for production of normal bone matrix, longitudinal bone growth, and normal skeletal development.
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Affiliation(s)
- Ilaria Musante
- DiNOGMI, University of Genoa, via Gaslini 5, 16148 Genoa, Italy.
| | - Deborah Mattinzoli
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico, via Pace 9, 20122 Milan, Italy; Fondazione D'Amico per la Ricerca sulle Malattie Renali, via Pace 9, 20122 Milan, Italy.
| | | | - Simone Bossi
- DiNOGMI, University of Genoa, via Gaslini 5, 16148 Genoa, Italy.
| | - Masami Ikehata
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico, via Pace 9, 20122 Milan, Italy; Fondazione D'Amico per la Ricerca sulle Malattie Renali, via Pace 9, 20122 Milan, Italy.
| | - Chiara Gentili
- Laboratory of Regenerative Medicine, DIMES, IRCCS AOU San Martino-IST, Largo Rosanna Benzi 10, University of Genova, Genova, Italy.
| | - Giuliana Cangemi
- Clinical Pathology Laboratory Unit, Istituto Giannina Gaslini, via Gaslini 5, 16148 Genoa, Italy.
| | - Cinzia Gatti
- Clinical Pathology Laboratory Unit, Istituto Giannina Gaslini, via Gaslini 5, 16148 Genoa, Italy.
| | - Laura Emionite
- Animal Facility, IRCCS A.U.O. San Martino-IST, Largo Rosanna Benzi 10, Genoa, Italy.
| | - Piergiorgio Messa
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico, via Pace 9, 20122 Milan, Italy; Fondazione D'Amico per la Ricerca sulle Malattie Renali, via Pace 9, 20122 Milan, Italy.
| | - Roberto Ravazzolo
- DiNOGMI, University of Genoa, via Gaslini 5, 16148 Genoa, Italy; Medical Genetics Unit, Istituto Giannina Gaslini, via Gaslini 5, 16148 Genoa, Italy.
| | - Maria Pia Rastaldi
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico, via Pace 9, 20122 Milan, Italy; Fondazione D'Amico per la Ricerca sulle Malattie Renali, via Pace 9, 20122 Milan, Italy.
| | - Daniela Riccardi
- School of Biosciences, Cardiff University, Cardiff, United Kingdom.
| | - Aldamaria Puliti
- DiNOGMI, University of Genoa, via Gaslini 5, 16148 Genoa, Italy; Medical Genetics Unit, Istituto Giannina Gaslini, via Gaslini 5, 16148 Genoa, Italy.
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30
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Abstract
Presynaptic receptors are sites at which transmitters, locally formed mediators or hormones inhibit or facilitate the release of a given transmitter from its axon terminals. The interest in the identification of presynaptic receptors has faded in recent years and it may therefore be justified to give an overview of their occurrence in the autonomic and central nervous system; this review will focus on presynaptic receptors in human tissues. Autoreceptors are presynaptic receptors at which a given transmitter restrains its further release, though in some instances may also increase its release. Inhibitory autoreceptors represent a typical example of a negative feedback; they are tonically activated by the respective endogenous transmitter and/or are constitutively active. Autoreceptors also play a role under pathophysiological conditions, e.g. by limiting the massive noradrenaline release occurring during congestive heart failure. They can be used for therapeutic purposes; e.g., the α2-adrenoceptor antagonist mirtazapine is used as an antidepressant and the inverse histamine H3 receptor agonist pitolisant has been marketed as a new drug for the treatment of narcolepsy in 2016. Heteroreceptors are presynaptic receptors at which transmitters from adjacent neurons, locally formed mediators (e.g. endocannabinoids) or hormones (e.g. adrenaline) can inhibit or facilitate transmitter release; they may be subject to an endogenous tone. The constipating effect of the sympathetic nervous system or of the antihypertensive drug clonidine is related to the activation of inhibitory α2-adrenoceptors on postganglionic parasympathetic neurons. Part of the stimulating effect of adrenaline on the sympathetic nervous system during stress is related to its facilitatory effect on noradrenaline release via β2-adrenoceptors.
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Affiliation(s)
| | - Thomas Feuerstein
- Sektion Neuroelektronische Systeme, Klinik für Neurochirurgie, Universität Freiburg, Germany
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Xu C, Fitting S. Inhibition of GABAergic Neurotransmission by HIV-1 Tat and Opioid Treatment in the Striatum Involves μ-Opioid Receptors. Front Neurosci 2016; 10:497. [PMID: 27877102 PMCID: PMC5099255 DOI: 10.3389/fnins.2016.00497] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 10/17/2016] [Indexed: 01/07/2023] Open
Abstract
Due to combined antiretroviral therapy (cART), human immunodeficiency virus type 1 (HIV-1) is considered a chronic disease with high prevalence of mild forms of neurocognitive impairments, also referred to as HIV-associated neurocognitive disorders (HAND). Although opiate drug use can exacerbate HIV-1 Tat-induced neuronal damage, it remains unknown how and to what extent opioids interact with Tat on the GABAergic system. We conducted whole-cell recordings in mouse striatal slices and examined the effects of HIV-1 Tat in the presence and absence of morphine (1 μM) and damgo (1 μM) on GABAergic neurotransmission. Results indicated a decrease in the frequency and amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) and miniature IPSCs (mIPSCs) by Tat (5–50 nM) in a concentration-dependent manner. The significant Tat-induced decrease in IPSCs was abolished when removing extracellular and/or intracellular calcium. Treatment with morphine or damgo alone significantly decreased the frequency, but not amplitude of IPSCs. Interestingly, morphine but not damgo indicated an additional downregulation of the mean frequency of mIPSCs in combination with Tat. Pretreatment with naloxone (1 μM) and CTAP (1 μM) prevented the Tat-induced decrease in sIPSCs frequency but only naloxone prevented the combined Tat and morphine effect on mIPSCs frequency. Results indicate a Tat- or opioid-induced decrease in GABAergic neurotransmission via μ-opioid receptors with combined Tat and morphine effects involving additional opioid receptor-related mechanisms. Exploring the interactions between Tat and opioids on the GABAergic system may help to guide future research on HAND in the context of opiate drug use.
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Affiliation(s)
- Changqing Xu
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill Chapel Hill, NC, USA
| | - Sylvia Fitting
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill Chapel Hill, NC, USA
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Hu XT. HIV-1 Tat-Mediated Calcium Dysregulation and Neuronal Dysfunction in Vulnerable Brain Regions. Curr Drug Targets 2016; 17:4-14. [PMID: 26028040 DOI: 10.2174/1389450116666150531162212] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 05/26/2015] [Indexed: 01/08/2023]
Abstract
Despite the success of combined antiretroviral therapy, more than half of HIV-1-infected patients in the USA show HIV-associated neurological and neuropsychiatric deficits. This is accompanied by anatomical and functional alterations in vulnerable brain regions of the mesocorticolimbic and nigrostriatal systems that regulate cognition, mood and motivation-driven behaviors, and could occur at early stages of infection. Neurons are not infected by HIV, but HIV-1 proteins (including but not limited to the HIV-1 trans-activator of transcription, Tat) induce Ca(2+) dysregulation, indicated by abnormal and excessive Ca(2+) influx and increased intracellular Ca(2+) release that consequentially elevate cytosolic free Ca(2+) levels ([Ca(2+)]in). Such alterations in intracellular Ca(2+) homeostasis significantly disturb normal functioning of neurons, and induce dysregulation, injury, and death of neurons or non-neuronal cells, and associated tissue loss in HIV-vulnerable brain regions. This review discusses certain unique mechanisms, particularly the over-activation and/or upregulation of the ligand-gated ionotropic glutamatergic NMDA receptor (NMDAR), the voltage-gated L-type Ca(2+) channel (L-channel) and the transient receptor potential canonical (TRPC) channel (a non-selective cation channel that is also permeable for Ca(2+)), which may underlie the deleterious effects of Tat on intracellular Ca(2+) homeostasis and neuronal hyper-excitation that could ultimately result in excitotoxicity. This review also seeks to provide summarized information for future studies focusing on comprehensive elucidation of molecular mechanisms underlying the pathophysiological effects of Tat (as well as some other HIV-1 proteins and immunoinflammatory molecules) on neuronal function, particularly in HIV-vulnerable brain regions.
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Affiliation(s)
- Xiu-Ti Hu
- Department of Pharmacology, Rush University Medical Center, Cohn Research Building, Rm. 414, 1735 W. Harrison Street, Chicago, IL 60612, USA.
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Pittaluga A. Presynaptic Release-Regulating mGlu1 Receptors in Central Nervous System. Front Pharmacol 2016; 7:295. [PMID: 27630571 PMCID: PMC5006178 DOI: 10.3389/fphar.2016.00295] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/22/2016] [Indexed: 01/14/2023] Open
Abstract
Group I metabotropic glutamate (mGlu) receptors consists of mGlu1 and mGlu5 receptor subtypes. These receptors are widely distributed in the central nervous system (CNS), where they preferentially mediate facilitatory signaling in neurones and glial cells, mainly by favoring phospholipase (PLC) translocation. Based on the literature so far available, group I Metabotropic glutamate receptors (mGluRs) are preferentially expressed at the postsynaptic side of chemical synapsis, where they participate in the progression of the chemical stimulus. Studies, however, have shown the presence of these receptors also at the presynaptic level, where they exert several functions, including the modulation of transmitter exocytosis. Presynaptic Group I mGluRs can be both autoreceptors regulating release of glutamate and heteroreceptors regulating the release of various transmitters, including GABA, dopamine, noradrenaline, and acetylcholine. While the existence of presynaptic release-regulating mGlu5 receptors is largely recognized, the possibility that mGlu1 receptors also are present at this level has been a matter of discussion for a long time. A large body of evidence published in the last decade, however, supports this notion. This review aims at revisiting the data from in vitro studies concerning the existence and the role of release-regulating mGlu1 receptors presynaptically located in nerve terminals isolated from selected regions of the CNS. The functional interaction linking mGlu5 and mGlu1 receptor subtypes at nerve terminals and their relative contributions as modulators of central transmission will also be discussed. We apologize in advance for omission in our coverage of the existing literature.
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Affiliation(s)
- Anna Pittaluga
- Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of GenoaGenoa, Italy
- Center of Excellence for Biomedical Research, University of GenoaGenoa, Italy
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Di Prisco S, Olivero G, Merega E, Bonfiglio T, Marchi M, Pittaluga A. CXCR4 and NMDA Receptors Are Functionally Coupled in Rat Hippocampal Noradrenergic and Glutamatergic Nerve Endings. J Neuroimmune Pharmacol 2016; 11:645-656. [PMID: 27147258 DOI: 10.1007/s11481-016-9677-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/25/2016] [Indexed: 01/31/2023]
Abstract
Previous studies had shown that the HIV-1 capsidic glycoprotein gp120 (strain IIIB) modulates presynaptic release-regulating NMDA receptors on noradrenergic and glutamatergic terminals. This study aims to assess whether the chemokine CXC4 receptors (CXCR4s) has a role in the gp120-mediated effects. The effect of CXCL12, the endogenous ligand at CXCR4, on the NMDA-mediated releasing activity was therefore investigated. Rat hippocampal synaptosomes were preloaded with [3H]noradrenaline ([3H]NA) or [3H]D-aspartate ([3H]D-Asp) and acutely exposed to CXCL12, to NMDA or to both agonists. CXCL12, inactive on its own, facilitated the NMDA-evoked tritium release. The NMDA antagonist MK-801 abolished the NMDA/CXCL12-evoked tritium release of both radiolabelled tracers, while the CXCR4 antagonist AMD 3100 halved it, suggesting that rat hippocampal nerve endings possess presynaptic release-regulating CXCR4 receptors colocalized with NMDA receptors. Accordingly, Western blot analysis confirmed the presence of CXCR4 proteins in synaptosomal plasmamembranes. In both synaptosomal preparations, CXCL12-induced facilitation of NMDA-mediated release was dependent upon PLC-mediated src-induced events leading to mobilization of Ca2+ from intraterminal IP3-sensitive stores Finally, the gp120-induced facilitation of NMDA-mediated release of [3H]NA and [3H]D-Asp was prevented by AMD 3100. We propose that CXCR4s are functionally coupled to NMDA receptors in rat hippocampal noradrenergic and glutamatergic terminals and account for the gp120-induced modulation of the NMDA-mediated central effects. The NMDA/CXCR4 cross-talk could have a role in the neuropsychiatric symptoms often observed in HIV-1 positive patients.
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Affiliation(s)
- Silvia Di Prisco
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Guendalina Olivero
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Elisa Merega
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Tommaso Bonfiglio
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Mario Marchi
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy.,Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy. .,Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy.
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Saylor D, Dickens AM, Sacktor N, Haughey N, Slusher B, Pletnikov M, Mankowski JL, Brown A, Volsky DJ, McArthur JC. HIV-associated neurocognitive disorder--pathogenesis and prospects for treatment. Nat Rev Neurol 2016; 12:234-48. [PMID: 26965674 DOI: 10.1038/nrneurol.2016.27] [Citation(s) in RCA: 557] [Impact Index Per Article: 69.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the past two decades, several advancements have improved the care of HIV-infected individuals. Most importantly, the development and deployment of combination antiretroviral therapy (CART) has resulted in a dramatic decline in the rate of deaths from AIDS, so that people living with HIV today have nearly normal life expectancies if treated with CART. The term HIV-associated neurocognitive disorder (HAND) has been used to describe the spectrum of neurocognitive dysfunction associated with HIV infection. HIV can enter the CNS during early stages of infection, and persistent CNS HIV infection and inflammation probably contribute to the development of HAND. The brain can subsequently serve as a sanctuary for ongoing HIV replication, even when systemic viral suppression has been achieved. HAND can remain in patients treated with CART, and its effects on survival, quality of life and everyday functioning make it an important unresolved issue. In this Review, we describe the epidemiology of HAND, the evolving concepts of its neuropathogenesis, novel insights from animal models, and new approaches to treatment. We also discuss how inflammation is sustained in chronic HIV infection. Moreover, we suggest that adjunctive therapies--treatments targeting CNS inflammation and other metabolic processes, including glutamate homeostasis, lipid and energy metabolism--are needed to reverse or improve HAND-related neurological dysfunction.
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Affiliation(s)
- Deanna Saylor
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Alex M Dickens
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Ned Sacktor
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Norman Haughey
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Barbara Slusher
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Mikhail Pletnikov
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Joseph L Mankowski
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Amanda Brown
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - David J Volsky
- The Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, New York 10029, USA
| | - Justin C McArthur
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
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Krogh KA, Green MV, Thayer SA. HIV-1 Tat-induced changes in synaptically-driven network activity adapt during prolonged exposure. Curr HIV Res 2015; 12:406-14. [PMID: 25613136 DOI: 10.2174/1570162x13666150121110402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 11/13/2014] [Accepted: 12/23/2014] [Indexed: 11/22/2022]
Abstract
HIV-associated neurocognitive disorders (HAND) afflict approximately half of HIV-infected patients. The HIV-1 transactivator of transcription (Tat) protein is released by infected cells and contributes to the pathogenesis of HAND, but many of the underlying mechanisms remain poorly understood. Here we used fura-2-based Ca(2+) imaging and whole-cell patch-clamp recording to study the effects of Tat on the spontaneous synaptic activity that occurs in networked rat hippocampal neurons in culture. Tat triggered aberrant network activity that exhibited a decrease in the frequency of spontaneous action potential bursts and Ca(2+) spikes with a simultaneous increase in burst duration and Ca(2+) spike amplitude. These network changes were apparent after 4 h treatment with Tat and required the low-density lipoprotein receptor-related protein (LRP). Interestingly, Tat-induced changes in network activity adapted during 24 h exposure. The activity returned to control levels in the maintained presence of Tat for 24 h. These observations indicate that Tat causes aberrant network activity, which is dependent on LRP, and adapts following prolonged exposure. Changes in network excitability may contribute to Tat-induced neurotoxicity in vitro and seizure disorders in vivo. Adaptation of neural networks may be a neuroprotective response to the sustained presence of the neurotoxic protein Tat and could underlie the behavioral and electrophysiological changes observed in HAND.
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Affiliation(s)
| | | | - Stanley A Thayer
- Department of Pharmacology, University of Minnesota, 6-120 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA.
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Merega E, Prisco SD, Severi P, Kalfas F, Pittaluga A. Antibody/receptor protein immunocomplex in human and mouse cortical nerve endings amplifies complement-induced glutamate release. Neurosci Lett 2015; 600:50-5. [PMID: 26049008 DOI: 10.1016/j.neulet.2015.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 05/31/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022]
Abstract
Previous studies have demonstrated that complement alone releases glutamate from human and mouse cortical terminals in an antibody-independent manner. In order to expand our knowledge on complement-mediated effects, we investigated whether the presence of an antigen-antibody complex in synaptosomal plasmamembranes could also trigger complement-induced functional responses that might affect neurotransmitter release. To this aim, we focused on the chemokine 5 receptor (CCR5) expressed in human and mouse cortical glutamate terminals, whose activation by CCL5 elicits [(3)H]D-aspartate ([(3)H]D-ASP) release. Preincubating synaptosomes with an antibody recognizing the NH2 terminus of the CCR5 protein (anti-NH2-CCR5 antibody) abolished the CCL5-induced [(3)H]D-ASP release. Similarly, enriching synaptosomes with an antibody recognizing the COOH terminus of CCR5 (anti-COOH-CCR5 antibody) prevented the CCL5-induced [(3)H]D-ASP release. The antagonist-like activity of the anti-NH2-CCR5 antibody turned to facilitation when anti-NH2-CCR5-treated synaptosomes were exposed to complement. In these terminals, the releasing effect was significantly higher than that elicited by complement in untreated synaptosomes. On the contrary, the complement-induced [(3)H]D-ASP release from anti-COOH-CCR5 antibody-entrapped synaptosomes did not differ from that from untreated synaptosomes. Preincubating synaptosomes with anti-beta tubulin III antibody, used as negative control, neither prevented the CCL5-induced releasing effect nor it amplified the complement-induced [(3)H]D-ASP release. Finally, serum lacking the C1q protein, i.e. the protein essential to promote the antibody-mediated activation of complement, elicited a comparable [(3)H]D-ASP release from both untreated and anti-NH2-CCR5 antibody-treated synaptosomes. Thus, we propose that antibodies raised against the outer sequence of a receptor protein can trigger the activation of the complement through the classic, C1q-mediated antibody-dependent pathway, which results in an abnormal release of glutamate that could be deleterious to central nervous system.
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Affiliation(s)
- Elisa Merega
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Silvia Di Prisco
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Paolo Severi
- Division of Neurosurgery, Galliera Hospital, Genoa, Italy
| | - Fotios Kalfas
- Division of Neurosurgery, Galliera Hospital, Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy; Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.
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Di Prisco S, Merega E, Lanfranco M, Casazza S, Uccelli A, Pittaluga A. Acute desipramine restores presynaptic cortical defects in murine experimental autoimmune encephalomyelitis by suppressing central CCL5 overproduction. Br J Pharmacol 2014; 171:2457-67. [PMID: 24528439 DOI: 10.1111/bph.12631] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/14/2014] [Accepted: 02/05/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Altered glutamate exocytosis and cAMP production in cortical terminals of experimental autoimmune encephalomyelitis (EAE) mice occur at the early stage of disease (13 days post-immunization, d.p.i.). Neuronal defects were paralleled by overexpression of the central chemokine CCL5 (also known as RANTES), suggesting it has a role in presynaptic impairments. We propose that drugs able to restore CCL5 content to physiological levels could also restore presynaptic defects. Because of its efficacy in controlling CCL5 overexpression, desipramine (DMI) appeared to be a suitable candidate to test our hypothesis. EXPERIMENTAL APPROACH Control and EAE mice at 13 d.p.i. were acutely or chronically administered DMI and monitored for behaviour and clinical scores. Noradrenaline and glutamate release, cAMP, CCL5 and TNF-α production were quantified in cortical synaptosomes and homogenates. Peripheral cytokine production was also determined. KEY RESULTS Noradrenaline exocytosis and α₂ -adrenoeceptor-mediated activity were unmodified in EAE mice at 13 d.p.i. when compared with control. Acute, but not chronic, DMI reduced CCL5 levels in cortical homogenates of EAE mice at 13 d.p.i., but did not affect peripheral IL-17 and TNF-α contents or CCL5 plasma levels. Acute DMI caused a long-lasting restoration of glutamate exocytosis, restored endogenous cAMP production and impeded the shift from inhibition to facilitation of the CCL5-mediated control of glutamate exocytosis. Finally, DMI ameliorated anxiety-related behaviour but not motor activity or severity of clinical signs. CONCLUSIONS We propose DMI as an add-on therapy to normalize neuropsychiatric symptoms in multiple sclerosis patients at the early stage of the disease.
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Affiliation(s)
- Silvia Di Prisco
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Genoa, Italy
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Merega E, Prisco SD, Lanfranco M, Severi P, Pittaluga A. Complement selectively elicits glutamate release from nerve endings in different regions of mammal central nervous system. J Neurochem 2014; 129:473-83. [DOI: 10.1111/jnc.12650] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 12/29/2013] [Accepted: 01/02/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Elisa Merega
- Department of Pharmacy; Pharmacology and Toxicology Section; University of Genoa; Genoa Italy
| | - Silvia Di Prisco
- Department of Pharmacy; Pharmacology and Toxicology Section; University of Genoa; Genoa Italy
| | | | - Paolo Severi
- Division of Neurosurgery; Galliera Hospital; Genoa Italy
| | - Anna Pittaluga
- Department of Pharmacy; Pharmacology and Toxicology Section; University of Genoa; Genoa Italy
- Center of Excellence for Biomedical Research; University of Genoa; Genoa Italy
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Bagashev A, Sawaya BE. Roles and functions of HIV-1 Tat protein in the CNS: an overview. Virol J 2013; 10:358. [PMID: 24359561 PMCID: PMC3879180 DOI: 10.1186/1743-422x-10-358] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 12/06/2013] [Indexed: 01/01/2023] Open
Abstract
Nearly 50% of HIV-infected individuals suffer from some form of HIV-associated neurocognitive disorders (HAND). HIV-1 Tat (a key HIV transactivator of transcription) protein is one of the first HIV proteins to be expressed after infection occurs and is absolutely required for the initiation of the HIV genome transcription. In addition to its canonical functions, various studies have shown the deleterious role of HIV-1 Tat in the development and progression of HAND. Within the CNS, only specific cell types can support productive viral replication (astrocytes and microglia), however Tat protein can be released form infected cells to affects HIV non-permissive cells such as neurons. Therefore, in this review, we will summarize the functions of HIV-1 Tat proteins in neural cells and its ability to promote HAND.
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Affiliation(s)
| | - Bassel E Sawaya
- Molecular Studies of Neurodegenerative Diseases Lab, The Fels Institute for Cancer Research & Molecular Biology, Philadelphia, PA 19140, USA.
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CCL5-glutamate interaction in central nervous system: Early and acute presynaptic defects in EAE mice. Neuropharmacology 2013; 75:337-46. [PMID: 23958452 DOI: 10.1016/j.neuropharm.2013.07.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 07/24/2013] [Accepted: 07/30/2013] [Indexed: 01/15/2023]
Abstract
We investigated the CCL5-glutamate interaction in the cortex and in the spinal cord from mice with Experimental Autoimmune Encephalomyelitis (EAE) at 13 and 21/30 days post immunization (d.p.i.), representing the onset and the peak of the disease, respectively. An early reduction of the KCl-evoked glutamate release was observed in cortical terminals from EAE mice at 13 d.p.i., persisting until 21/30 d.p.i. A concomitant reduction of the depolarization-evoked cyclic adenosine monophosphate (cAMP), but not of the inositol 1,4,5-trisphosphate (IP3) cortical production also occurred at 13 d.p.i, that still was detectable at the acute stage of disease (21 dp.i.). Inasmuch, the CCL5-mediated inhibition of glutamate exocytosis observed in control mice turned to facilitation in EAE mouse cortex at 13 d.p.i., then becoming undetectable at 21/30 d.p.i. Differently, glutamate exocytosis, as well as IP3 and cAMP productions were unaltered in spinal cord synaptosomes from EAE mice at 13 d.p.i., but significantly increased at 21/30 d.p.i., while the presynaptic CCL5-mediated facilitation of glutamate exocytosis observed in control mice remained unchanged. In both CNS regions, the presynaptic defects were parallelled by increased CCL5 availability. Inasmuch, the presynaptic defects so far described in EAE mice were reminiscent of the effects acute CCL5 exerts in control conditions. Based on these observations we propose that increased CCL5 bioavailability could have a role in determining the abovedescribed impaired presynaptic impairments in both CNS regions. These presynaptic defects could be relevant to the onset of early cognitive impairments and acute neuroinflammation and demyelinating processes observed in multiple sclerosis patients.
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Increased excitability in tat-transgenic mice: Role of tat in HIV-related neurological disorders. Neurobiol Dis 2013; 55:110-9. [DOI: 10.1016/j.nbd.2013.02.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 02/03/2013] [Accepted: 02/19/2013] [Indexed: 11/20/2022] Open
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Rossi PIA, Musante I, Summa M, Pittaluga A, Emionite L, Ikehata M, Rastaldi MP, Ravazzolo R, Puliti A. Compensatory molecular and functional mechanisms in nervous system of the Grm1(crv4) mouse lacking the mGlu1 receptor: a model for motor coordination deficits. ACTA ACUST UNITED AC 2012; 23:2179-89. [PMID: 22791805 DOI: 10.1093/cercor/bhs200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, the only members of group I mGlu receptors, are implicated in synaptic plasticity and mechanisms of feedback control of glutamate release. They exhibit nearly complementary distributions throughout the central nervous system, well evident in the cerebellum, where mGlu1 receptor is most intensely expressed while mGlu5 receptor is not. Despite their different distribution, they show a similar subcellular localization and use common transducing pathways. We recently described the Grm1(crv4) mouse with motor coordination deficits and renal anomalies caused by a spontaneous mutation inactivating the mGlu1 receptor. To define the neuropathological mechanisms in these mice, we evaluated expression and function of the mGlu5 receptor in cerebral and cerebellar cortices. Western blot and immunofluorescence analyses showed mGlu5 receptor overexpression. Quantitative reverse transcriptase-polymerase chain reaction results indicated that the up-regulation is already evident at RNA level. Functional studies confirmed an enhanced glutamate release from cortical cerebral and cerebellar synaptosomes when compared with wild-type that is abolished by the mGlu5 receptor-specific inhibitor, 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP). Finally, acute MPEP treatment of Grm1(crv4/crv4) mice induced an evident although incomplete improvement of motor coordination, suggesting that mGlu5 receptors enhanced activity worsens, instead of improving, the motor-coordination defects in the Grm1(crv4/crv4) mice.
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Giribaldi F, Milanese M, Bonifacino T, Anna Rossi PI, Di Prisco S, Pittaluga A, Tacchetti C, Puliti A, Usai C, Bonanno G. Group I metabotropic glutamate autoreceptors induce abnormal glutamate exocytosis in a mouse model of amyotrophic lateral sclerosis. Neuropharmacology 2012; 66:253-63. [PMID: 22634363 DOI: 10.1016/j.neuropharm.2012.05.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 04/26/2012] [Accepted: 05/13/2012] [Indexed: 10/28/2022]
Abstract
Glutamate-mediated excitotoxicity plays a major role in ALS and reduced astrocytic glutamate transport was suggested as a cause. Based on previous work we have proposed that abnormal release may represent another source of excessive glutamate. In this line, here we studied the modulation of glutamate release in ALS by Group I metabotropic glutamate (mGlu) receptors, that comprise mGlu1 and mGlu5 members. Synaptosomes from the lumbar spinal cord of SOD1/G93A mice, a widely used murine model for human ALS, and controls were used in release, confocal or electron microscopy and Western blot experiments. Concentrations of the mGlu1/5 receptor agonist 3,5-DHPG >0.3 μM stimulated the release of [(3)H]d- aspartate, used to label the releasing pools of glutamate, both in control and SOD1/G93A mice. At variance, ≤0.3 μM 3,5-DHPG increased [(3)H]d-aspartate release in SOD1/G93A mice only. Experiments with selective antagonists indicated the involvement of both mGlu1 and mGlu5 receptors, mGlu5 being preferentially involved in the high potency effects of 3,5-DHPG. High 3,5-DHPG concentrations increased IP3 formation in both mouse strains, whereas low 3,5-DHPG did it in SOD1/G93A mice only. Release experiments confirmed that 3,5-DHPG elicited [(3)H]d-aspartate exocytosis involving intra-terminal Ca(2+) release through IP3-sensitive channels. Confocal microscopy indicated the co-existence of both receptors presynaptically in the same glutamatergic nerve terminal in SOD1/G93A mice. To conclude, activation of mGlu1/5 receptors produced abnormal glutamate release in SOD1/G93A mice, suggesting that these receptors are implicated in ALS and that selective antagonists may be predicted for new therapeutic approaches. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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Affiliation(s)
- Francesco Giribaldi
- Department of Experimental Medicine Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
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Tryoen-Tóth P, Chasserot-Golaz S, Tu A, Gherib P, Bader MF, Beaumelle B, Vitale N. HIV-1 Tat protein inhibits neurosecretion by binding to phosphatidylinositol (4,5) bisphosphate. J Cell Sci 2012. [DOI: 10.1242/jcs.111658] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 Tat enables viral transcription and is also actively released by infected cells. Extracellular Tat can enter uninfected cells and affect some cellular functions. Here, we examine the effects of Tat protein on the secretory activity of neuroendocrine cells. When added to the culture medium of chromaffin and PC12 cells, Tat was actively internalized and strongly impaired exocytosis as measured by carbon fiber amperometry and growth hormone (GH) release assay. Expression of Tat mutants that do not bind to phosphatidylinositol-(4,5)-bisphophate (PI(4,5)P2) did not affect secretion, and overexpression of phosphatidylinositol 4 phosphate 5-kinase (PIP5K), the major PI(4,5)P2 synthesizing enzyme, significantly rescued the Tat-induced inhibition of neurosecretion. This suggests that the inhibition of exocytosis may be the consequence of PI(4,5)P2 sequestration. Accordingly expression of Tat in PC12 cells interfered with the secretagogue-dependent recruitment of annexin A2 to the plasma membrane, a PI(4,5)P2-binding protein that promotes the formation of lipid microdomains that are required for exocytosis. In addition Tat significantly prevented the reorganization of the actin cytoskeleton necessary for the movement of secretory vesicles towards plasma membrane fusion sites. Thus, the capacity of extracellular Tat to enter neuroendocrine cells and sequester plasma membrane PI(4,5)P2 perturbs several PI(4,5)P2-dependent players of the exocytotic machinery, thereby affecting neurosecretion. We propose that Tat-induced inhibition of exocytosis is involved in the neuronal disorders associated with HIV-1 infection.
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Sidorkiewicz M, Brocka M, Bronis M, Grek M, Jozwiak B, Piekarska A, Bartkowiak J. The altered expression of α1 and β3 subunits of the gamma-aminobutyric acid A receptor is related to the hepatitis C virus infection. Eur J Clin Microbiol Infect Dis 2011; 31:1537-42. [PMID: 22080424 PMCID: PMC3364423 DOI: 10.1007/s10096-011-1475-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 10/20/2011] [Indexed: 01/02/2023]
Abstract
The modulation of the gamma-aminobutyric acid type A (GABA A) receptors activity was observed in several chronic hepatitis failures, including hepatitis C. The expression of GABA A receptor subunits α1 and β3 was detected in peripheral blood mononuclear cells (PBMCs) originated from healthy donors. The aim of the study was to evaluate if GABA A α1 and β3 expression can also be observed in PBMCs from chronic hepatitis C (CHC) patients and to evaluate a possible association between their expression and the course of hepatitis C virus (HCV) infection. GABA A α1- and β3-specific mRNAs presence and a protein expression in PBMCs from healthy donors and CHC patients were screened by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. In patients, HCV RNA was determined in sera and PBMCs. It was shown that GABA A α1 and β3 expression was significantly different in PBMCs from CHC patients and healthy donors. In comparison to healthy donors, CHC patients were found to present an increase in the expression of GABA A α1 subunit and a decrease in the expression of β3 subunit in their PBMCs. The modulation of α1 and β3 GABA A receptors subunits expression in PBMCs may be associated with ongoing or past HCV infection.
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Affiliation(s)
- M Sidorkiewicz
- Department of Medical Biochemistry, Medical University of Łódź, Łódź, Poland.
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Glutamate excitotoxicity is involved in the induction of paralysis in mice after infection by a human coronavirus with a single point mutation in its spike protein. J Virol 2011; 85:12464-73. [PMID: 21957311 DOI: 10.1128/jvi.05576-11] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Human coronaviruses (HCoV) are recognized respiratory pathogens, and some strains, including HCoV-OC43, can infect human neuronal and glial cells of the central nervous system (CNS) and activate neuroinflammatory mechanisms. Moreover, HCoV-OC43 is neuroinvasive, neurotropic, and neurovirulent in susceptible mice, where it induces chronic encephalitis. Herein, we show that a single point mutation in the viral spike (S) glycoprotein (Y241H), acquired during viral persistence in human neural cells, led to a hind-limb paralytic disease in infected mice. Inhibition of glutamate excitotoxicity using a 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propranoic acid (AMPA) receptor antagonist (GYKI-52466) improved clinical scores related to the paralysis and motor disabilities in S mutant virus-infected mice, as well as protected the CNS from neuronal dysfunctions, as illustrated by restoration of the phosphorylation state of neurofilaments. Expression of the glial glutamate transporter GLT-1, responsible for glutamate homeostasis, was downregulated following infection, and GYKI-52466 also significantly restored its steady-state expression level. Finally, GYKI-52466 treatment of S mutant virus-infected mice led to reduced microglial activation, which may lead to improvement in the regulation of CNS glutamate homeostasis. Taken together, our results strongly suggest an involvement of excitotoxicity in the paralysis-associated neuropathology induced by an HCoV-OC43 mutant which harbors a single point mutation in its spike protein that is acquired upon persistent virus infection.
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