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Schenck JK, Karl MT, Clarkson-Paredes C, Bastin A, Pushkarsky T, Brichacek B, Miller RH, Bukrinsky MI. Extracellular vesicles produced by HIV-1 Nef-expressing cells induce myelin impairment and oligodendrocyte damage in the mouse central nervous system. J Neuroinflammation 2024; 21:127. [PMID: 38741181 DOI: 10.1186/s12974-024-03124-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 05/04/2024] [Indexed: 05/16/2024] Open
Abstract
HIV-associated neurocognitive disorders (HAND) are a spectrum of cognitive impairments that continue to affect approximately half of all HIV-positive individuals despite effective viral suppression through antiretroviral therapy (ART). White matter pathologies have persisted in the ART era, and the degree of white matter damage correlates with the degree of neurocognitive impairment in patients with HAND. The HIV protein Nef has been implicated in HAND pathogenesis, but its effect on white matter damage has not been well characterized. Here, utilizing in vivo, ex vivo, and in vitro methods, we demonstrate that Nef-containing extracellular vesicles (Nef EVs) disrupt myelin sheaths and inflict damage upon oligodendrocytes within the murine central nervous system. Intracranial injection of Nef EVs leads to reduced myelin basic protein (MBP) staining and a decreased number of CC1 + oligodendrocytes in the corpus callosum. Moreover, cerebellar slice cultures treated with Nef EVs exhibit diminished MBP expression and increased presence of unmyelinated axons. Primary mixed brain cultures and enriched oligodendrocyte precursor cell cultures exposed to Nef EVs display a decreased number of O4 + cells, indicative of oligodendrocyte impairment. These findings underscore the potential contribution of Nef EV-mediated damage to oligodendrocytes and myelin maintenance in the pathogenesis of HAND.
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Affiliation(s)
- Jessica K Schenck
- School of Medicine and Health Sciences, The George Washington University, 2300 I St NW, Ross Hall 624, Washington, DC, 20037, USA
| | - Molly T Karl
- School of Medicine and Health Sciences, The George Washington University, 2300 I St NW, Ross Hall 624, Washington, DC, 20037, USA
| | - Cheryl Clarkson-Paredes
- School of Medicine and Health Sciences, The George Washington University, 2300 I St NW, Ross Hall 624, Washington, DC, 20037, USA
| | - Ashley Bastin
- School of Medicine and Health Sciences, The George Washington University, 2300 I St NW, Ross Hall 624, Washington, DC, 20037, USA
| | - Tatiana Pushkarsky
- School of Medicine and Health Sciences, The George Washington University, 2300 I St NW, Ross Hall 624, Washington, DC, 20037, USA
| | - Beda Brichacek
- School of Medicine and Health Sciences, The George Washington University, 2300 I St NW, Ross Hall 624, Washington, DC, 20037, USA
| | - Robert H Miller
- School of Medicine and Health Sciences, The George Washington University, 2300 I St NW, Ross Hall 624, Washington, DC, 20037, USA
| | - Michael I Bukrinsky
- School of Medicine and Health Sciences, The George Washington University, 2300 I St NW, Ross Hall 624, Washington, DC, 20037, USA.
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2
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Sviridov D, Bukrinsky M. Neuro-HIV-New insights into pathogenesis and emerging therapeutic targets. FASEB J 2023; 37:e23301. [PMID: 37942865 PMCID: PMC11032165 DOI: 10.1096/fj.202301239rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 10/22/2023] [Accepted: 10/25/2023] [Indexed: 11/10/2023]
Abstract
HIV-associated neurocognitive disorders (HAND) is a term describing a complex set of cognitive impairments accompanying HIV infection. Successful antiretroviral therapy (ART) reduces the most severe forms of HAND, but milder forms affect over 50% of people living with HIV (PLWH). Pathogenesis of HAND in the ART era remains unknown. A variety of pathogenic factors, such as persistent HIV replication in the brain reservoir, HIV proteins released from infected brain cells, HIV-induced neuroinflammation, and some components of ART, have been implicated in driving HAND pathogenesis in ART-treated individuals. Here, we propose another factor-impairment of cholesterol homeostasis and lipid rafts by HIV-1 protein Nef-as a possible contributor to HAND pathogenesis. These effects of Nef on cholesterol may also underlie the effects of other pathogenic factors that constitute the multifactorial nature of HAND pathogenesis. The proposed Nef- and cholesterol-focused mechanism may provide a long-sought unified explanation of HAND pathogenesis that takes into account all contributing factors. Evidence for the impairment by Nef of cellular cholesterol balance, potential effects of this impairment on brain cells, and opportunities to therapeutically target this element of HAND pathogenesis are discussed.
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Affiliation(s)
- Dmitri Sviridov
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Michael Bukrinsky
- The George Washington University School of Medicine and Health Sciences, Washington, DC, USA
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3
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Namba MD, Xie Q, Barker JM. Advancing the preclinical study of comorbid neuroHIV and substance use disorders: Current perspectives and future directions. Brain Behav Immun 2023; 113:453-475. [PMID: 37567486 PMCID: PMC10528352 DOI: 10.1016/j.bbi.2023.07.021] [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: 02/28/2023] [Revised: 06/23/2023] [Accepted: 07/30/2023] [Indexed: 08/13/2023] Open
Abstract
Human immunodeficiency virus (HIV) remains a persistent public health concern throughout the world. Substance use disorders (SUDs) are a common comorbidity that can worsen treatment outcomes for people living with HIV. The relationship between HIV infection and SUD outcomes is likely bidirectional, making clear interrogation of neurobehavioral outcomes challenging in clinical populations. Importantly, the mechanisms through which HIV and addictive drugs disrupt homeostatic immune and CNS function appear to be highly overlapping and synergistic within HIV-susceptible reward and motivation circuitry in the central nervous system. Decades of animal research have revealed invaluable insights into mechanisms underlying the pathophysiology SUDs and HIV, although translational studies examining comorbid SUDs and HIV are very limited due to the technical challenges of modeling HIV infection preclinically. In this review, we discuss preclinical animal models of HIV and highlight key pathophysiological characteristics of each model, with a particular emphasis on rodent models of HIV. We then review the implementation of these models in preclinical SUD research and identify key gaps in knowledge in the field. Finally, we discuss how cutting-edge behavioral neuroscience tools, which have revealed key insights into the neurobehavioral mechanisms of SUDs, can be applied to preclinical animal models of HIV to reveal potential, novel treatment avenues for comorbid HIV and SUDs. Here, we argue that future preclinical SUD research would benefit from incorporating comorbidities such as HIV into animal models and would facilitate the discovery of more refined, subpopulation-specific mechanisms and effective SUD prevention and treatment targets.
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Affiliation(s)
- Mark D Namba
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Qiaowei Xie
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Jacqueline M Barker
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA.
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4
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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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5
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Williams ME, Williams AA, Naudé PJW. Viral protein R (Vpr)-induced neuroinflammation and its potential contribution to neuronal dysfunction: a scoping review. BMC Infect Dis 2023; 23:512. [PMID: 37545000 PMCID: PMC10405499 DOI: 10.1186/s12879-023-08495-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 07/30/2023] [Indexed: 08/08/2023] Open
Abstract
HIV-associated neurocognitive disorders (HAND) are the result of the activity of HIV-1 within the central nervous system (CNS). While the introduction of antiretroviral therapy (ART) has significantly reduced the occurrence of severe cases of HAND, milder cases still persist. The persistence of HAND in the modern ART era has been linked to a chronic dysregulated inflammatory profile. There is increasing evidence suggesting a potential role of Viral protein R (Vpr) in dysregulating the neuroinflammatory processes in people living with HIV (PLHIV), which may contribute to the development of HAND. Since the role of Vpr in neuroinflammatory mechanisms has not been clearly defined, we conducted a scoping review of fundamental research studies on this topic. The review aimed to assess the size and scope of available research literature on this topic and provide commentary on whether Vpr contributes to neuroinflammation, as highlighted in fundamental studies. Based on the specified selection criteria, 10 studies (6 of which were cell culture-based and 4 that included both animal and cell culture experiments) were eligible for inclusion. The main findings were that (1) Vpr can increase neuroinflammatory markers, with studies consistently reporting higher levels of TNF-α and IL-8, (2) Vpr induces (neuro)inflammation via specific pathways, including the PI3K/AKT, p38-MAPk, JNK-SAPK and Sur1-Trpm4 channels in astrocytes and the p38 and JNK-SAPK in myeloid cells, and (3) Vpr-specific protein amino acid signatures (73R, 77R and 80A) may play an important role in exacerbating neuroinflammation and the neuropathophysiology of HAND. Therefore, Vpr should be investigated for its potential contribution to neuroinflammation in the development of HAND.
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Affiliation(s)
| | | | - Petrus J W Naudé
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
- Neuroscience Institute, University of Cape Town, Cape Town, South Africa
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6
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Wahl A, Al-Harthi L. HIV infection of non-classical cells in the brain. Retrovirology 2023; 20:1. [PMID: 36639783 PMCID: PMC9840342 DOI: 10.1186/s12977-023-00616-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
HIV-associated neurological disorders (HAND) affect up to 50% of people living with HIV (PLWH), even in the era of combination antiretroviral therapy (cART). HIV-DNA can be detected in the cerebral spinal fluid (CSF) of approximately half of aviremic ART-suppressed PLWH and its presence is associated with poorer neurocognitive performance. HIV DNA + and HIV RNA + cells have also been observed in postmortem brain tissue of individuals with sustained cART suppression. In this review, we provide an overview of how HIV invades the brain and HIV infection of resident brain glial cells (astrocytes and microglia). We also discuss the role of resident glial cells in persistent neuroinflammation and HAND in PLWH and their potential contribution to the HIV reservoir. HIV eradication strategies that target persistently infected glia cells will likely be needed to achieve HIV cure.
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Affiliation(s)
- Angela Wahl
- grid.10698.360000000122483208International Center for the Advancement of Translational Science, University of North Carolina at Chapel Hill, Chapel Hill, NC USA ,grid.10698.360000000122483208Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC USA ,grid.10698.360000000122483208Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Lena Al-Harthi
- grid.240684.c0000 0001 0705 3621Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL USA
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7
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Donoso M, D’Amico D, Valdebenito S, Hernandez CA, Prideaux B, Eugenin EA. Identification, Quantification, and Characterization of HIV-1 Reservoirs in the Human Brain. Cells 2022; 11:2379. [PMID: 35954221 PMCID: PMC9367788 DOI: 10.3390/cells11152379] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/19/2022] [Accepted: 07/26/2022] [Indexed: 02/04/2023] Open
Abstract
The major barrier to cure HIV infection is the early generation and extended survival of HIV reservoirs in the circulation and tissues. Currently, the techniques used to detect and quantify HIV reservoirs are mostly based on blood-based assays; however, it has become evident that viral reservoirs remain in tissues. Our study describes a novel multi-component imaging method (HIV DNA, mRNA, and viral proteins in the same assay) to identify, quantify, and characterize viral reservoirs in tissues and blood products obtained from HIV-infected individuals even when systemic replication is undetectable. In the human brains of HIV-infected individuals under ART, we identified that microglia/macrophages and a small population of astrocytes are the main cells with integrated HIV DNA. Only half of the cells with integrated HIV DNA expressed viral mRNA, and one-third expressed viral proteins. Surprisingly, we identified residual HIV-p24, gp120, nef, vpr, and tat protein expression and accumulation in uninfected cells around HIV-infected cells suggesting local synthesis, secretion, and bystander uptake. In conclusion, our data show that ART reduces the size of the brain's HIV reservoirs; however, local/chronic viral protein secretion still occurs, indicating that the brain is still a major anatomical target to cure HIV infection.
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Affiliation(s)
| | | | | | | | | | - Eliseo A. Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, Fifth Floor, 105 11th Street, Galveston, TX 77555, USA; (M.D.); (D.D.); (S.V.); (C.A.H.); (B.P.)
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8
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Seth P. Insights Into the Role of Mortalin in Alzheimer’s Disease, Parkinson’s Disease, and HIV-1-Associated Neurocognitive Disorders. Front Cell Dev Biol 2022; 10:903031. [PMID: 35859895 PMCID: PMC9292388 DOI: 10.3389/fcell.2022.903031] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/06/2022] [Indexed: 11/13/2022] Open
Abstract
Mortalin is a chaperone protein that regulates physiological functions of cells. Its multifactorial role allows cells to survive pathological conditions. Pharmacological, chemical, and siRNA-mediated downregulation of mortalin increases oxidative stress, mitochondrial dysfunction leading to unregulated inflammation. In addition to its well-characterized function in controlling oxidative stress, mitochondrial health, and maintaining physiological balance, recent evidence from human brain autopsies and cell culture–based studies suggests a critical role of mortalin in attenuating the damage seen in several neurodegenerative diseases. Overexpression of mortalin provides an important line of defense against accumulated proteins, inflammation, and neuronal loss, a key characteristic feature observed in neurodegeneration. Neurodegenerative diseases are a group of progressive disorders, sharing pathological features in Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and HIV-associated neurocognitive disorder. Aggregation of insoluble amyloid beta-proteins and neurofibrillary tangles in Alzheimer’s disease are among the leading cause of neuropathology in the brain. Parkinson’s disease is characterized by the degeneration of dopamine neurons in substantia nigra pars compacta. A substantial synaptic loss leading to cognitive decline is the hallmark of HIV-associated neurocognitive disorder (HAND). Brain autopsies and cell culture studies showed reduced expression of mortalin in Alzheimer’s, Parkinson’s, and HAND cases and deciphered the important role of mortalin in brain cells. Here, we discuss mortalin and its regulation and describe how neurotoxic conditions alter the expression of mortalin and modulate its functions. In addition, we also review the neuroprotective role of mortalin under neuropathological conditions. This knowledge showcases the importance of mortalin in diverse brain functions and offers new opportunities for the development of therapeutic targets that can modulate the expression of mortalin using chemical compounds.
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Affiliation(s)
- Pankaj Seth
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Gurgaon, India
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9
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Ye F, Alvarez-Carbonell D, Nguyen K, Leskov K, Garcia-Mesa Y, Sreeram S, Valadkhan S, Karn J. Recruitment of the CoREST transcription repressor complexes by Nerve Growth factor IB-like receptor (Nurr1/NR4A2) mediates silencing of HIV in microglial cells. PLoS Pathog 2022; 18:e1010110. [PMID: 35797416 PMCID: PMC9295971 DOI: 10.1371/journal.ppat.1010110] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 07/19/2022] [Accepted: 06/15/2022] [Indexed: 12/13/2022] Open
Abstract
Human immune deficiency virus (HIV) infection in the brain leads to chronic neuroinflammation due to the production of pro-inflammatory cytokines, which in turn promotes HIV transcription in infected microglial cells. However, powerful counteracting silencing mechanisms in microglial cells result in the rapid shutdown of HIV expression after viral reactivation to limit neuronal damage. Here we investigated whether the Nerve Growth Factor IB-like nuclear receptor Nurr1 (NR4A2), which is a repressor of inflammation in the brain, acts directly to restrict HIV expression. HIV silencing following activation by TNF-α, or a variety of toll-like receptor (TLR) agonists, in both immortalized human microglial cells (hμglia) and induced pluripotent stem cells (iPSC)-derived human microglial cells (iMG) was enhanced by Nurr1 agonists. Similarly, overexpression of Nurr1 led to viral suppression, while conversely, knock down (KD) of endogenous Nurr1 blocked HIV silencing. The effect of Nurr1 on HIV silencing is direct: Nurr1 binds directly to the specific consensus binding sites in the U3 region of the HIV LTR and mutation of the Nurr1 DNA binding domain blocked its ability to suppress HIV-1 transcription. Chromatin immunoprecipitation (ChIP) assays also showed that after Nurr1 binding to the LTR, the CoREST/HDAC1/G9a/EZH2 transcription repressor complex is recruited to the HIV provirus. Finally, transcriptomic studies demonstrated that in addition to repressing HIV transcription, Nurr1 also downregulated numerous cellular genes involved in inflammation, cell cycle, and metabolism, further promoting HIV latency and microglial homoeostasis. Nurr1 therefore plays a pivotal role in modulating the cycles of proviral reactivation by potentiating the subsequent proviral transcriptional shutdown. These data highlight the therapeutic potential of Nurr1 agonists for inducing HIV silencing and microglial homeostasis and ultimately for the amelioration of the neuroinflammation associated with HIV-associated neurocognitive disorders (HAND).
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Affiliation(s)
- Fengchun Ye
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - David Alvarez-Carbonell
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Kien Nguyen
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Konstantin Leskov
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Yoelvis Garcia-Mesa
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Sheetal Sreeram
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Saba Valadkhan
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
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10
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Rifaximin Improves Spatial Learning and Memory Impairment in Rats with Liver Damage-Associated Neuroinflammation. Biomedicines 2022; 10:biomedicines10061263. [PMID: 35740285 PMCID: PMC9219896 DOI: 10.3390/biomedicines10061263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/23/2022] [Accepted: 05/26/2022] [Indexed: 12/04/2022] Open
Abstract
Patients with non-alcoholic fatty liver disease (NAFLD) may show mild cognitive impairment. Neuroinflammation in the hippocampus mediates cognitive impairment in rat models of minimal hepatic encephalopathy (MHE). Treatment with rifaximin reverses cognitive impairment in a large proportion of cirrhotic patients with MHE. However, the underlying mechanisms remain unclear. The aims of this work were to assess if rats with mild liver damage, as a model of NAFLD, show neuroinflammation in the hippocampus and impaired cognitive function, if treatment with rifaximin reverses it, and to study the underlying mechanisms. Mild liver damage was induced with carbon-tetrachloride. Infiltration of immune cells, glial activation, and cytokine expression, as well as glutamate receptors expression in the hippocampus and cognitive function were assessed. We assessed the effects of daily treatment with rifaximin on the alterations showed by these rats. Rats with mild liver damage showed hippocampal neuroinflammation, reduced membrane expression of glutamate N-methyl-D-aspartate (NMDA) receptor subunits, and impaired spatial memory. Increased C-C Motif Chemokine Ligand 2 (CCL2), infiltration of monocytes, microglia activation, and increased tumor necrosis factor α (TNFα) were reversed by rifaximin, that normalized NMDA receptor expression and improved spatial memory. Thus, rifaximin reduces neuroinflammation and improves cognitive function in rats with mild liver damage, being a promising therapy for patients with NAFLD showing mild cognitive impairment.
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11
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Retroviral infection of human neurospheres and use of stem Cell EVs to repair cellular damage. Sci Rep 2022; 12:2019. [PMID: 35132117 PMCID: PMC8821538 DOI: 10.1038/s41598-022-05848-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 01/05/2022] [Indexed: 12/18/2022] Open
Abstract
HIV-1 remains an incurable infection that is associated with substantial economic and epidemiologic impacts. HIV-associated neurocognitive disorders (HAND) are commonly linked with HIV-1 infection; despite the development of combination antiretroviral therapy (cART), HAND is still reported to affect at least 50% of HIV-1 infected individuals. It is believed that the over-amplification of inflammatory pathways, along with release of toxic viral proteins from infected cells, are primarily responsible for the neurological damage that is observed in HAND; however, the underlying mechanisms are not well-defined. Therefore, there is an unmet need to develop more physiologically relevant and reliable platforms for studying these pathologies. In recent years, neurospheres derived from induced pluripotent stem cells (iPSCs) have been utilized to model the effects of different neurotropic viruses. Here, we report the generation of neurospheres from iPSC-derived neural progenitor cells (NPCs) and we show that these cultures are permissive to retroviral (e.g. HIV-1, HTLV-1) replication. In addition, we also examine the potential effects of stem cell derived extracellular vesicles (EVs) on HIV-1 damaged cells as there is abundant literature supporting the reparative and regenerative properties of stem cell EVs in the context of various CNS pathologies. Consistent with the literature, our data suggests that stem cell EVs may modulate neuroprotective and anti-inflammatory properties in damaged cells. Collectively, this study demonstrates the feasibility of NPC-derived neurospheres for modeling HIV-1 infection and, subsequently, highlights the potential of stem cell EVs for rescuing cellular damage induced by HIV-1 infection.
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12
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Rivera-Ortiz J, Pla-Tenorio J, Cruz ML, Colon K, Perez-Morales J, Rodriguez JA, Martinez-Sicari J, Noel RJ. Blockade of beta adrenergic receptors protects the blood brain barrier and reduces systemic pathology caused by HIV-1 Nef protein. PLoS One 2021; 16:e0259446. [PMID: 34784367 PMCID: PMC8594844 DOI: 10.1371/journal.pone.0259446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/19/2021] [Indexed: 01/14/2023] Open
Abstract
Combination antiretroviral therapy (cART) targets viral replication, but early viral protein production by astrocytes may still occur and contribute to the progression of HIV-1 associated neurocognitive disorders and secondary complications seen in patients receiving cART. In prior work with our model, astrocytic HIV-1 Nef expression exhibits neurotoxic effects leading to neurological damage, learning impairment, and immune upregulation that induces inflammation in the lungs and small intestine (SI). In this follow-up study, we focus on the sympathetic nervous system (SNS) as the important branch for peripheral inflammation resulting from astrocytic Nef expression. Male and female Sprague Dawley rats were infused with transfected astrocytes to produce Nef. The rats were divided in four groups: Nef, Nef + propranolol, propranolol and naïve. The beta-adrenergic blocker, propranolol, was administered for 3 consecutive days, starting one day prior to surgery. Two days after the surgery, the rats were sacrificed, and then blood, brain, small intestine (SI), and lung tissues were collected. Levels of IL-1β were higher in both male and female rats, and treatment with propranolol restored IL-1β to basal levels. We observed that Nef expression decreased staining of the tight junction protein claudin-5 in brain tissue while animals co-treated with propranolol restored claudin-5 expression. Lungs and SI of rats in the Nef group showed histological signs of damage including larger Peyer's Patches, increased tissue thickness, and infiltration of immune cells; these findings were abrogated by propranolol co-treatment. Results suggest that interruption of the beta adrenergic signaling reduces the peripheral organ inflammation caused after Nef expression in astrocytes of the brain.
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Affiliation(s)
- Jocelyn Rivera-Ortiz
- HIV-1 Immunopathogenesis Laboratory, The Wistar Institute, Philadelphia, PA, United States of America
| | - Jessalyn Pla-Tenorio
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico
| | - Myrella L. Cruz
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico
| | - Krystal Colon
- HIV-1 Immunopathogenesis Laboratory, The Wistar Institute, Philadelphia, PA, United States of America
| | - Jaileene Perez-Morales
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico
| | - Julio A. Rodriguez
- Cooper University Hospital Department of Orthopaedic Surgery, Camden, NJ, United States of America
| | - Jorge Martinez-Sicari
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico
| | - Richard J. Noel
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico
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13
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Alzheimer's-Like Pathology at the Crossroads of HIV-Associated Neurological Disorders. Vaccines (Basel) 2021; 9:vaccines9080930. [PMID: 34452054 PMCID: PMC8402792 DOI: 10.3390/vaccines9080930] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 12/19/2022] Open
Abstract
Despite the widespread success of combined antiretroviral therapy (cART) in suppressing viremia, the prevalence of human immunodeficiency virus (HIV)-associated neurological disorders (HAND) and associated comorbidities such as Alzheimer’s disease (AD)-like symptomatology is higher among people living with HIV. The pathophysiology of observed deficits in HAND is well understood. However, it has been suggested that it is exacerbated by aging. Epidemiological studies have suggested comparable concentrations of the toxic amyloid protein, amyloid-β42 (Aβ42), in the cerebrospinal fluid (CSF) of HAND patients and in the brains of patients with dementia of the Alzheimer’s type. Apart from abnormal amyloid-β (Aβ) metabolism in AD, a better understanding of the role of similar pathophysiologic processes in HAND could be of substantial value. The pathogenesis of HAND involves either the direct effects of the virus or the effect of viral proteins, such as Tat, Gp120, or Nef, as well as the effects of antiretrovirals on amyloid metabolism and tauopathy, leading, in turn, to synaptodendritic alterations and neuroinflammatory milieu in the brain. Additionally, there is a lack of knowledge regarding the causative or bystander role of Alzheimer’s-like pathology in HAND, which is a barrier to the development of therapeutics for HAND. This review attempts to highlight the cause–effect relationship of Alzheimer’s-like pathology with HAND, attempting to dissect the role of HIV-1, HIV viral proteins, and antiretrovirals in patient samples, animal models, and cell culture model systems. Biomarkers associated with Alzheimer’s-like pathology can serve as a tool to assess the neuronal injury in the brain and the associated cognitive deficits. Understanding the factors contributing to the AD-like pathology associated with HAND could set the stage for the future development of therapeutics aimed at abrogating the disease process.
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Wen J, Cheever T, Wang L, Wu D, Reed J, Mascola J, Chen X, Liu C, Pegu A, Sacha JB, Lu Y, Haigwood NL, Chen ISY. Improved delivery of broadly neutralizing antibodies by nanocapsules suppresses SHIV infection in the CNS of infant rhesus macaques. PLoS Pathog 2021; 17:e1009738. [PMID: 34283885 PMCID: PMC8323878 DOI: 10.1371/journal.ppat.1009738] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 07/30/2021] [Accepted: 06/22/2021] [Indexed: 12/31/2022] Open
Abstract
Broadly neutralizing antibodies (bNAbs) directed to HIV-1 have shown promise at suppressing viremia in animal models. However, the use of bNAbs for the central nervous system (CNS) infection is confounded by poor penetration of the blood brain barrier (BBB). Typically, antibody concentrations in the CNS are extremely low; with levels in cerebrospinal fluid (CSF) only 0.1% of blood concentrations. Using a novel nanotechnology platform, which we term nanocapsules, we show effective transportation of the human bNAb PGT121 across the BBB in infant rhesus macaques upon systemic administration up to 1.6% of plasma concentration. We demonstrate that a single dose of PGT121 encased in nanocapsules when delivered at 48h post-infection delays early acute infection with SHIVSF162P3 in infants, with one of four animals demonstrating viral clearance. Importantly, the nanocapsule delivery of PGT121 improves suppression of SHIV infection in the CNS relative to controls. In patients where HIV-1 is fully suppressed by antiretroviral drugs, HIV-1 still persists in reservoirs. If antiretroviral drugs are stopped, the virus will emerge from these reservoirs and re-seeds systemically. The central nervous system (CNS) is proposed to be a tissue compartment that harbors other HIV-1 reservoirs. A key obstacle that constrains the treatment for the CNS infection is the blood–brain barrier (BBB), a highly restrictive barrier separating the circulating blood from the brain and extracellular fluid in the CNS, which impedes ~98% of the small molecule therapeutics and almost all macromolecules including broadly neutralizing antibodies (bNAbs) directed to HIV-1. Our “nanocapsule” strategy is based on a nanotechnology wherein bNAb molecules are encapsulated within nanocapsules of which the surface contains abundant choline and acetylcholine analogues. This design allows the nanocapsules to effectively cross the BBB to deliver bNAbs into the CNS upon systemic administration and show an impact of bNAb on CNS reservoirs in SHIV infected infant macaques.
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Affiliation(s)
- Jing Wen
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles (UCLA), UCLA AIDS Institute, Los Angeles, California, United States of America
| | - Tracy Cheever
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States of America
| | - Lan Wang
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles (UCLA), UCLA AIDS Institute, Los Angeles, California, United States of America
| | - Di Wu
- Department of Chemical and Biomolecular Engineering, School of Engineering, UCLA, Los Angeles, California, United States of America
| | - Jason Reed
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, United States of America
| | - John Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda Maryland, United States of America
| | - Xuejun Chen
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda Maryland, United States of America
| | - Cuiping Liu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda Maryland, United States of America
| | - Amarendra Pegu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda Maryland, United States of America
| | - Jonah B Sacha
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States of America.,Vaccine & Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, United States of America
| | - Yunfeng Lu
- Department of Chemical and Biomolecular Engineering, School of Engineering, UCLA, Los Angeles, California, United States of America
| | - Nancy L Haigwood
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States of America
| | - Irvin S Y Chen
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles (UCLA), UCLA AIDS Institute, Los Angeles, California, United States of America
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Yarandi SS, Duggan MR, Sariyer IK. Emerging Role of Nef in the Development of HIV Associated Neurological Disorders. J Neuroimmune Pharmacol 2021; 16:238-250. [PMID: 33123948 PMCID: PMC8081738 DOI: 10.1007/s11481-020-09964-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 10/08/2020] [Indexed: 01/13/2023]
Abstract
Despite adherence to treatment, individuals living with HIV have an increased risk for developing cognitive impairments, referred to as HIV-associated neurological disorders (HAND). Due to continued growth in the HIV population, particularly amongst the aging cohort, the neurobiological mechanisms of HAND are increasingly relevant. Similar to other viral proteins (e.g. Tat, Gp120, Vpr), the Negative Factor (Nef) is associated with numerous adverse effects in the CNS as well as cognitive impairments. In particular, emerging data indicate the consequences of Nef may be facilitated by the modulation of cellular autophagy as well as its inclusion into extracellular vesicles (EVs). The present review examines evidence for the molecular mechanisms by which Nef might contribute to neuronal dysfunction underlying HAND, with a specific focus on autophagy and EVs. Based on the these data, we propose an integrated model by which Nef may contribute to underlying neuronal dysfunction in HAND and highlight potentially novel therapeutic targets for HAND. Graphical abstract.
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Affiliation(s)
- Shadan S Yarandi
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 North Broad Street, Medical Education and Research Building Room 753, 7th Floor, Philadelphia, PA, 19140, USA
| | - Michael R Duggan
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 North Broad Street, Medical Education and Research Building Room 753, 7th Floor, Philadelphia, PA, 19140, USA
| | - Ilker K Sariyer
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 North Broad Street, Medical Education and Research Building Room 753, 7th Floor, Philadelphia, PA, 19140, USA.
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Sil S, Thangaraj A, Chivero ET, Niu F, Kannan M, Liao K, Silverstein PS, Periyasamy P, Buch S. HIV-1 and drug abuse comorbidity: Lessons learned from the animal models of NeuroHIV. Neurosci Lett 2021; 754:135863. [PMID: 33794296 DOI: 10.1016/j.neulet.2021.135863] [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: 12/01/2020] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023]
Abstract
Various research studies that have investigated the association between HIV infection and addiction underpin the role of various drugs of abuse in impairing immunological and non-immunological pathways of the host system, ultimately leading to augmentation of HIV infection and disease progression. These studies have included both in vitro and in vivo animal models wherein investigators have assessed the effects of various drugs on several disease parameters to decipher the impact of drugs on both HIV infection and progression of HIV-associated neurocognitive disorders (HAND). However, given the inherent limitations in the existing animal models of HAND, these investigations only recapitulated specific aspects of the disease but not the complex human syndrome. Despite the inability of HIV to infect rodents over the last 30 years, multiple strategies have been employed to develop several rodent models of HAND. While none of these models can accurately mimic the overall pathophysiology of HAND, they serve the purpose of modeling some unique aspects of HAND. This review provides an overview of various animal models used in the field and a careful evaluation of methodological strengths and limitations inherent in both the model systems and study designs to understand better how the various animal models complement one another.
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Affiliation(s)
- Susmita Sil
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Annadurai Thangaraj
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Ernest T Chivero
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Fang Niu
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Muthukumar Kannan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Ke Liao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Peter S Silverstein
- School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, 64108, USA
| | - Palsamy Periyasamy
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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Duggan MR, Mohseni Ahooyi T, Parikh V, Khalili K. Neuromodulation of BAG co-chaperones by HIV-1 viral proteins and H 2O 2: implications for HIV-associated neurological disorders. Cell Death Discov 2021; 7:60. [PMID: 33771978 PMCID: PMC7997901 DOI: 10.1038/s41420-021-00424-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 01/04/2021] [Accepted: 01/30/2021] [Indexed: 11/08/2022] Open
Abstract
Despite increasing numbers of aged individuals living with HIV, the mechanisms underlying HIV-associated neurological disorders (HANDs) remain elusive. As HIV-1 pathogenesis and aging are characterized by oxidative stress as well as altered protein quality control (PQC), reactive oxygen species (ROS) themselves might constitute a molecular mediator of neuronal PQC by modulating BCL-2 associated athanogene (BAG) family members. Present results reveal H2O2 replicated and exacerbated a reduction in neuronal BAG3 induced by the expression of HIV-1 viral proteins (i.e., Tat and Nef), while also causing an upregulation of BAG1. Such a reciprocal regulation of BAG3 and BAG1 levels was also indicated in two animal models of HIV, the doxycycline-inducible Tat (iTat) and the Tg26 mouse. Inhibiting oxidative stress via antioxidants in primary culture was capable of partially preserving neuronal BAG3 levels as well as electrophysiological functioning otherwise altered by HIV-1 viral proteins. Current findings indicate HIV-1 viral proteins and H2O2 may mediate neuronal PQC by exerting synergistic effects on complementary BAG family members, and suggest novel therapeutic targets for the aging HIV-1 population.
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Affiliation(s)
- Michael R Duggan
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA
- Department of Psychology, College of Liberal Arts at Temple University, 1701 N 13th Street, 9th Floor, Philadelphia, PA, 19122, USA
| | - Taha Mohseni Ahooyi
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA
| | - Vinay Parikh
- Department of Psychology, College of Liberal Arts at Temple University, 1701 N 13th Street, 9th Floor, Philadelphia, PA, 19122, USA
| | - Kamel Khalili
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA.
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Misrielal C, Mauthe M, Reggiori F, Eggen BJL. Autophagy in Multiple Sclerosis: Two Sides of the Same Coin. Front Cell Neurosci 2020; 14:603710. [PMID: 33328897 PMCID: PMC7714924 DOI: 10.3389/fncel.2020.603710] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/26/2020] [Indexed: 01/08/2023] Open
Abstract
Multiple sclerosis (MS) is a complex auto-immune disorder of the central nervous system (CNS) that involves a range of CNS and immune cells. MS is characterized by chronic neuroinflammation, demyelination, and neuronal loss, but the molecular causes of this disease remain poorly understood. One cellular process that could provide insight into MS pathophysiology and also be a possible therapeutic avenue, is autophagy. Autophagy is an intracellular degradative pathway essential to maintain cellular homeostasis, particularly in neurons as defects in autophagy lead to neurodegeneration. One of the functions of autophagy is to maintain cellular homeostasis by eliminating defective or superfluous proteins, complexes, and organelles, preventing the accumulation of potentially cytotoxic damage. Importantly, there is also an intimate and intricate interplay between autophagy and multiple aspects of both innate and adaptive immunity. Thus, autophagy is implicated in two of the main hallmarks of MS, neurodegeneration, and inflammation, making it especially important to understand how this pathway contributes to MS manifestation and progression. This review summarizes the current knowledge about autophagy in MS, in particular how it contributes to our understanding of MS pathology and its potential as a novel therapeutic target.
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Affiliation(s)
- Chairi Misrielal
- Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Mario Mauthe
- Molecular Cell Biology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Fulvio Reggiori
- Molecular Cell Biology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Bart J L Eggen
- Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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Yarandi SS, Robinson JA, Vakili S, Donadoni M, Burdo TH, Sariyer IK. Characterization of Nef expression in different brain regions of SIV-infected macaques. PLoS One 2020; 15:e0241667. [PMID: 33137166 PMCID: PMC7605674 DOI: 10.1371/journal.pone.0241667] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 10/19/2020] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE HIV-associated CNS dysfunction is a significant problem among people with HIV (PWH), who now live longer due to viral suppression from combined anti-retroviral therapy (ART). Over the course of infection, HIV generates toxic viral proteins and induces inflammatory cytokines that have toxic effects on neurons in the CNS. Among these viral proteins, HIV Nef has been found in neurons of postmortem brain specimens from PWH. However, the source of Nef and its impact on neuronal cell homeostasis are still elusive. METHODS AND RESULTS Here, in using a simian immunodeficiency virus (SIV) infected rhesus macaque model of neuroHIV, we find SIV Nef reactivity in the frontal cortex, hippocampus and cerebellum of SIV-infected animals using immunohistochemistry (IHC). Interestingly, SIV-infected macaques treated with ART also showed frequent Nef positive cells in the cerebellum and hippocampus. Using dual quantitative RNAscope and IHC, we observed cells that were positive for Nef, but were not for SIV RNA, suggesting that Nef protein is present in cells that are not actively infected with SIV. Using cell specific markers, we observed Nef protein in microglia/macrophages and astrocytes. Importantly, we also identified a number of NeuN-positive neurons, which are not permissive to SIV infection, but contained Nef protein. Further characterization of Nef-positive neurons showed caspase 3 activation, indicating late stage apoptosis in the CNS neurons. CONCLUSIONS Our results suggest that regardless of ART status, Nef is expressed in the brain of SIV infected macaques and may contribute to neurological complications seen in PWH.
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Affiliation(s)
- Shadan S. Yarandi
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
| | - Jake A. Robinson
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
| | - Sarah Vakili
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
| | - Martina Donadoni
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
| | - Tricia H. Burdo
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
| | - Ilker K. Sariyer
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
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20
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Chang L, Liang H, Kandel SR, He JJ. Independent and Combined Effects of Nicotine or Chronic Tobacco Smoking and HIV on the Brain: A Review of Preclinical and Clinical Studies. J Neuroimmune Pharmacol 2020; 15:658-693. [PMID: 33108618 DOI: 10.1007/s11481-020-09963-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 02/07/2023]
Abstract
Tobacco smoking is highly prevalent among HIV-infected individuals. Chronic smokers with HIV showed greater cognitive deficits and impulsivity, and had more psychopathological symptoms and greater neuroinflammation than HIV non-smokers or smokers without HIV infection. However, preclinical studies that evaluated the combined effects of HIV-infection and tobacco smoking are scare. The preclinical models typically used cell cultures or animal models that involved specific HIV viral proteins or the administration of nicotine to rodents. These preclinical models consistently demonstrated that nicotine had neuroprotective and anti-inflammatory effects, leading to cognitive enhancement. Although the major addictive ingredient in tobacco smoking is nicotine, chronic smoking does not lead to improved cognitive function in humans. Therefore, preclinical studies designed to unravel the interactive effects of chronic tobacco smoking and HIV infection are needed. In this review, we summarized the preclinical studies that demonstrated the neuroprotective effects of nicotine, the neurotoxic effects of the HIV viral proteins, and the scant literature on nicotine or tobacco smoke in HIV transgenic rat models. We also reviewed the clinical studies that evaluated the neurotoxic effects of tobacco smoking, HIV infection and their combined effects on the brain, including studies that evaluated the cognitive and behavioral assessments, as well as neuroimaging measures. Lastly, we compared the different approaches between preclinical and clinical studies, identified some gaps and proposed some future directions. Graphical abstract Independent and combined effects of HIV and tobacco/nicotine. Left top and bottom panels: Both clinical studies of HIV infected persons and preclinical studies using viral proteins in vitro or in vivo in animal models showed that HIV infection could lead to neurotoxicity and neuroinflammation. Right top and bottom panels: While clinical studies of tobacco smoking consistently showed deleterious effects of smoking, clinical and preclinical studies that used nicotine show mild cognitive enhancement, neuroprotective and possibly anti-inflammatory effects. In the developing brain, however, nicotine is neurotoxic. Middle overlapping panels: Clinical studies of persons with HIV who were smokers typically showed additive deleterious effects of HIV and tobacco smoking. However, in the preclinical studies, when nicotine was administered to the HIV-1 Tg rats, the neurotoxic effects of HIV were attenuated, but tobacco smoke worsened the inflammatory cascade.
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Affiliation(s)
- Linda Chang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, 670 W. Baltimore Street, HSF III, Baltimore, MD, 21201, USA.
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI, USA.
| | - Huajun Liang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, 670 W. Baltimore Street, HSF III, Baltimore, MD, 21201, USA
| | - Suresh R Kandel
- Department of Microbiology and Immunology, Chicago Medical School, Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, 3333 Green Bay Road, Basic Science Building 2.300, North Chicago, IL, 60064, USA
| | - Johnny J He
- Department of Microbiology and Immunology, Chicago Medical School, Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, 3333 Green Bay Road, Basic Science Building 2.300, North Chicago, IL, 60064, USA.
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Omeragic A, Kayode O, Hoque MT, Bendayan R. Potential pharmacological approaches for the treatment of HIV-1 associated neurocognitive disorders. Fluids Barriers CNS 2020; 17:42. [PMID: 32650790 PMCID: PMC7350632 DOI: 10.1186/s12987-020-00204-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/30/2020] [Indexed: 02/06/2023] Open
Abstract
HIV associated neurocognitive disorders (HAND) are the spectrum of cognitive impairments present in patients infected with human immunodeficiency virus type 1 (HIV-1). The number of patients affected with HAND ranges from 30 to 50% of HIV infected individuals and although the development of combinational antiretroviral therapy (cART) has improved longevity, HAND continues to pose a significant clinical problem as the current standard of care does not alleviate or prevent HAND symptoms. At present, the pathological mechanisms contributing to HAND remain unclear, but evidence suggests that it stems from neuronal injury due to chronic release of neurotoxins, chemokines, viral proteins, and proinflammatory cytokines secreted by HIV-1 activated microglia, macrophages and astrocytes in the central nervous system (CNS). Furthermore, the blood-brain barrier (BBB) not only serves as a route for HIV-1 entry into the brain but also prevents cART therapy from reaching HIV-1 brain reservoirs, and therefore could play an important role in HAND. The goal of this review is to discuss the current data on the epidemiology, pathology and research models of HAND as well as address the potential pharmacological treatment approaches that are being investigated.
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Affiliation(s)
- Amila Omeragic
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON, M5S 3M2, Canada
| | - Olanre Kayode
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON, M5S 3M2, Canada
| | - Md Tozammel Hoque
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON, M5S 3M2, Canada
| | - Reina Bendayan
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON, M5S 3M2, Canada.
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HIV Nef and Antiretroviral Therapy Have an Inhibitory Effect on Autophagy in Human Astrocytes that May Contribute to HIV-Associated Neurocognitive Disorders. Cells 2020; 9:cells9061426. [PMID: 32526847 PMCID: PMC7349791 DOI: 10.3390/cells9061426] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/02/2020] [Accepted: 06/05/2020] [Indexed: 12/22/2022] Open
Abstract
A significant number of people living with HIV (PLWH) develop HIV-associated neurocognitive disorders (HAND) despite highly effective antiretroviral therapy (ART). Dysregulated macroautophagy (autophagy) is implicated in HAND pathogenesis. The viral protein Nef, expressed even with suppressive ART, and certain antiretrovirals affect autophagy in non-CNS cells. Astrocytes, vital for CNS microenvironment homeostasis and neuronal health, require autophagy for their own homeostasis. We hypothesized that extracellular Nef and/or ART impact astrocyte autophagy, thus contributing to HAND. We studied in-bulk and selective autophagic flux in primary human astrocytes treated with extracellular Nef and/or a combination of tenofovir+emtricitabine+raltegravir (ART) using Western blotting, a tandem fluorescent LC3 reporter, and transmission electron microscopy/morphometry. We show that after 24 h treatment, Nef and ART decrease autophagosomes through different mechanisms. While Nef accelerates autophagosome degradation without inducing autophagosome formation, ART inhibits autophagosome formation. Combination Nef+ART further depletes autophagosomes by inducing both abnormalities. Additionally, extracellular Nef and/or ART inhibit lysosomal degradation of p62, indicating Nef and/or ART affect in-bulk and selective autophagy differently. Dysregulation of both autophagic processes is maintained after 7 days of Nef and/or ART treatment. Persistent autophagy dysregulation due to chronic Nef and/or ART exposure may ultimately result in astrocyte and neuronal dysfunction, contributing to HAND.
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23
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Zhou YJ, Chen JM, Sapkota K, Long JY, Liao YJ, Jiang JJ, Liang BY, Wei JB, Zhou Y. Pananx notoginseng saponins attenuate CCL2-induced cognitive deficits in rats via anti-inflammation and anti-apoptosis effects that involve suppressing over-activation of NMDA receptors. Biomed Pharmacother 2020; 127:110139. [PMID: 32302948 DOI: 10.1016/j.biopha.2020.110139] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/22/2020] [Accepted: 03/30/2020] [Indexed: 12/12/2022] Open
Abstract
HIV-associated neurocognitive disorders (HAND) are characterized by synaptic damage and neuronal loss in the brain, ultimately leading to progressive decline of cognitive abilities and memory. Chemokine CC motif ligand 2 (CCL2) is elevated in cerebrospinal fluid (CSF), and has been believed to contribute to HAND. Previous studies by our research team have shown that CCL2 enhances N-Methyl-D-aspartate receptor (NMDAR)-mediated excitatory postsynaptic currents (EPSCs) and causes nerve cell damage. However, there are few drugs currently available to treat nerve damage that is caused by CCL2. Panax notoginseng saponins (PNS) are isolated from Panax notoginseng and benefit the human body in various ways, including the neuroprotective effect. However, the protective effect of PNS on CCL2-induced neurotoxicity remains unknown. In this study, we found that PNS improved CCL2-induced learning and memory impairment, and inhibited CCL2-induced cell death. These effects may be due to inhibiting over-activation of NMDA receptors by alleviating the dysfunction of glutamate metabolism. Furthermore, PNS-modulated CCL2-inducd intracellular oxidative stress was found to attenuate cell inflammation. Additionally, PNS pretreatment evidently inhibited apoptotic pathways by reducing the Bax/BCL-2 ratio and caspase-3, 8, 9 expressions. In conclusion, this study demonstrates that PNS provides substantial neuroprotection against CCL2-induced neurotoxicity, and may be a novel therapeutic agent in CCL2-induced HAND or other neurodegenerative diseases.
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Affiliation(s)
- Yi-Jun Zhou
- Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, 530021, China.
| | - Jian-Min Chen
- Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, 530021, China.
| | - Kiran Sapkota
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, United States
| | - Jiang-Yi Long
- Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, 530021, China
| | - Yuan-Jun Liao
- Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, 530021, China
| | - Jun-Jun Jiang
- Guangxi key laboratory of AIDS Prevention and Treatment, Guangxi Medical University, Nanning, Guangxi, 530021, China
| | - Bing-Yu Liang
- Guangxi key laboratory of AIDS Prevention and Treatment, Guangxi Medical University, Nanning, Guangxi, 530021, China
| | - Jin-Bin Wei
- Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, 530021, China.
| | - Yan Zhou
- Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, 530021, China.
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Ajasin D, Eugenin EA. HIV-1 Tat: Role in Bystander Toxicity. Front Cell Infect Microbiol 2020; 10:61. [PMID: 32158701 PMCID: PMC7052126 DOI: 10.3389/fcimb.2020.00061] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/06/2020] [Indexed: 12/21/2022] Open
Abstract
HIV Tat protein is a critical protein that plays multiple roles in HIV pathogenesis. While its role as the transactivator of HIV transcription is well-established, other non-viral replication-associated functions have been described in several HIV-comorbidities even in the current antiretroviral therapy (ART) era. HIV Tat protein is produced and released into the extracellular space from cells with active HIV replication or from latently HIV-infected cells into neighboring uninfected cells even in the absence of active HIV replication and viral production due to effective ART. Neighboring uninfected and HIV-infected cells can take up the released Tat resulting in the upregulation of inflammatory genes and activation of pathways that leads to cytotoxicity observed in several comorbidities such as HIV associated neurocognitive disorder (HAND), HIV associated cardiovascular impairment, and accelerated aging. Thus, understanding how Tat modulates host and viral response is important in designing novel therapeutic approaches to target the chronic inflammatory effects of soluble viral proteins in HIV infection.
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Affiliation(s)
- David Ajasin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, TX, United States
| | - Eliseo A Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, TX, United States
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25
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Chompre G, Martinez-Orengo N, Cruz M, Porter JT, Noel RJ. TGFβRI antagonist inhibits HIV-1 Nef-induced CC chemokine family ligand 2 (CCL2) in the brain and prevents spatial learning impairment. J Neuroinflammation 2019; 16:262. [PMID: 31829243 PMCID: PMC6905066 DOI: 10.1186/s12974-019-1664-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 11/27/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND HIV-1-associated neurocognitive disorders (HAND) progression is related to continued inflammation despite undetectable viral loads and may be caused by early viral proteins expressed by latently infected cells. Astrocytes represent an HIV reservoir in the brain where the early viral neurotoxin negative factor (Nef) is produced. We previously demonstrated that astrocytic expression of Nef in the hippocampus of rats causes inflammation, macrophage infiltration, and memory impairment. Since these processes are affected by TGFβ signaling pathways, and TGFβ-1 is found at higher levels in the central nervous system of HIV-1+ individuals and is released by astrocytes, we hypothesized a role for TGFβ-1 in our model of Nef neurotoxicity. METHODS To test this hypothesis, we compared cytokine gene expression by cultured astrocytes expressing Nef or green fluorescent protein. To determine the role of Nef and a TGFβRI inhibitor on memory and learning, we infused astrocytes expressing Nef into the hippocampus of rats and then treated them daily with an oral dose of SD208 (10 mg/kg) or placebo for 7 days. During this time, locomotor activity was recorded in an open field and spatial learning tested in the novel location recognition paradigm. Postmortem tissue analyses of inflammatory and signaling molecules were conducted using immunohistochemistry and immunofluorescence. RESULTS TGFβ-1 was induced in cultures expressing Nef at 24 h followed by CCL2 induction which was prevented by blocking TGFβRI with SD208 (competitive inhibitor). Interestingly, Nef seems to change the TGFβRI localization as suggested by the distribution of the immunoreactivity. Nef caused a deficit in spatial learning that was recovered upon co-administration of SD208. Brain tissue from Nef-treated rats given SD208 showed reduced CCL2, phospho-SMAD2, cluster of differentiation 163 (CD163), and GFAP immunoreactivity compared to the placebo group. CONCLUSIONS Consistent with our previous findings, rats treated with Nef showed deficits in spatial learning and memory in the novel location recognition task. In contrast, rats treated with Nef + SD208 showed better spatial learning suggesting that Nef disrupts memory formation in a TGFβ-1-dependent manner. The TGFβRI inhibitor further reduced the induction of inflammation by Nef which was concomitant with decreased TGFβ signaling. Our findings suggest that TGFβ-1 signaling is an intriguing target to reduce neuroHIV.
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Affiliation(s)
- Gladys Chompre
- Biology Department, Pontifical Catholic University of Puerto Rico, Ponce, Puerto Rico
| | - Neysha Martinez-Orengo
- Department of Basic Sciences, Ponce Health Sciences University-Ponce Medical School, Ponce Research Institute, P.O. Box 7004, Ponce, PR, 00731, USA
| | - Myrella Cruz
- Department of Basic Sciences, Ponce Health Sciences University-Ponce Medical School, Ponce Research Institute, P.O. Box 7004, Ponce, PR, 00731, USA
| | - James T Porter
- Department of Basic Sciences, Ponce Health Sciences University-Ponce Medical School, Ponce Research Institute, P.O. Box 7004, Ponce, PR, 00731, USA
| | - Richard J Noel
- Department of Basic Sciences, Ponce Health Sciences University-Ponce Medical School, Ponce Research Institute, P.O. Box 7004, Ponce, PR, 00731, USA.
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26
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Wang JL, Xu CJ. Astrocytes autophagy in aging and neurodegenerative disorders. Biomed Pharmacother 2019; 122:109691. [PMID: 31786465 DOI: 10.1016/j.biopha.2019.109691] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/11/2019] [Accepted: 11/20/2019] [Indexed: 12/13/2022] Open
Abstract
Astrocytes can serve multiple functions in maintaining cellular homeostasis of the central nervous system (CNS), and normal functions for autophagy in astrocytes is considered to have very vital roles in the pathogenesis of aging and neurodegenerative diseases. Autophagy is a major intracellular lysosomal (or its yeast analog, vacuolar) clearance pathways involved in the degradation and recycling of long-lived proteins, oxidatively damaged proteins and dysfunctional organelles by lysosomes. Current evidence has shown that autophagy might influence inflammation, oxidative stress, aging and function of astrocytes. Although the interrelation between autophagy and inflammation, oxidative stress, aging or neurological disorders have been addressed in detail, the influence of astrocytes mediated-autophagy in aging and neurodegenerative disorders has yet to be fully reviewed. In this review, we will summarize the most up-to-date findings and highlight the role of autophagy in astrocytes and link autophagy of astrocytes to aging and neurodegenerative diseases. Due to the prominent roles of astrocytic autophagy in age-related neurodegenerative diseases, we believe that we can provide new suggestions for the treatment of these disorders.
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Affiliation(s)
- Jun-Ling Wang
- Center for Reproductive Medicine, Affiliated Hospital 1 of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, PR China.
| | - Chao-Jin Xu
- Department of Histology & Embryology, School of Basic Medical Science, Wenzhou Medical University, Cha Shan University Town, No.1 Central North Road, Wenzhou, Zhejiang, 325035, PR China.
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27
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Rivera J, Isidro RA, Loucil-Alicea RY, Cruz ML, Appleyard CB, Isidro AA, Chompre G, Colon-Rivera K, Noel RJ. Infusion of HIV-1 Nef-expressing astrocytes into the rat hippocampus induces enteropathy and interstitial pneumonitis and increases blood-brain-barrier permeability. PLoS One 2019; 14:e0225760. [PMID: 31774879 PMCID: PMC6881014 DOI: 10.1371/journal.pone.0225760] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 11/12/2019] [Indexed: 12/16/2022] Open
Abstract
Even though HIV-1 replication can be suppressed by combination antiretroviral therapy (cART) inflammatory processes still occur, contributing to comorbidities. Comorbidities are attributed to variety of factors, including HIV-1 mediated inflammation. Several HIV-1 proteins mediate central nervous system (CNS) inflammation, including Nef. Nef is an early HIV-1 protein, toxic to neurons and glia and is sufficient to cause learning impairment similar to some deficits observed in HIV-1 associated neurocognitive disorders. To determine whether hippocampal Nef expression by astrocytes contributes to comorbidities, specifically peripheral inflammation, we infused Sprague Dawley rats with GFP- (control) or Nef-transfected astrocytes into the right hippocampus. Brain, lung, and ileum were collected postmortem for the measurement of inflammatory markers. Increased blood-brain-barrier permeability and serum IL-1β levels were detected in the Nef-treated rats. The lungs of Nef-treated rats demonstrated leukocyte infiltration, macrophage upregulation, and enhanced vascular permeability. Ileal tissue showed reactive follicular lymphoid hyperplasia, increased permeability and macrophage infiltration. The intracerebroventricular application of IL-1 receptor antagonist reduced infiltration of immune cells into ileum and lung, indicating the important role of IL-1β in mediating the spread of inflammation from the brain to other tissues. This suggests that localized expression of a single viral protein, HIV-1 Nef, can contribute to a broader inflammatory response by upregulation of IL-1β. Further, these results suggest that Nef contributes to the chronic inflammation seen in HIV patients, even in those whose viremia is controlled by cART.
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Affiliation(s)
- Jocelyn Rivera
- HIV-1 Immunopathogenesis Laboratory, The Wistar Institute, Philadelphia, PA, United States of America
| | - Raymond A. Isidro
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico, United States of America
| | - Raisa Y. Loucil-Alicea
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico, United States of America
| | - Myrella L. Cruz
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico, United States of America
| | - Caroline B. Appleyard
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico, United States of America
| | - Angel A. Isidro
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico, United States of America
| | - Gladys Chompre
- Department of Biology, Pontifical Catholic University of Puerto Rico, Ponce, Puerto Rico, United States of America
| | - Krystal Colon-Rivera
- HIV-1 Immunopathogenesis Laboratory, The Wistar Institute, Philadelphia, PA, United States of America
| | - Richard J. Noel
- Department of Basic Sciences, Ponce Health Sciences University, Ponce Research Institute, Ponce, Puerto Rico, United States of America
- * E-mail:
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Santerre M, Wang Y, Arjona S, Allen C, Sawaya BE. Differential Contribution of HIV-1 Subtypes B and C to Neurological Disorders: Mechanisms and Possible Treatments. AIDS Rev 2019; 21:76-83. [PMID: 31332398 DOI: 10.24875/aidsrev.19000051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With the introduction of combinatory antiretroviral therapy, patients infected with human immunodeficiency virus type 1 (HIV-1) can live much longer than before. However, the identification of HIV-associated neurocognitive disorder (HAND), especially HIV-associated dementia in 15-20% of patients infected with HIV-1, indicates additional complexity. These disorders turn out to be subtype dependent. Recently, many studies are ongoing trying to understand how the virus induces neuronal injury which could lead to neurological dysfunction. Most of these studies are focusing on the HIV-1 release of proteins such as Tat. However, the exact role of these proteins and their involvement in neuronal degeneration remains unidentified; this is especially true since viral proteins from different HIV-1 subtypes differ in their ability to cause neuronal damage. This review describes the role of different HIV-1 subtypes, identifies probable pathways involved in neuronal damage, the contribution of different HIV-1 subtypes to the progression of HAND, and potential treatments for HAND.
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Affiliation(s)
- Maryline Santerre
- Molecular Studies of Neurodegenerative Diseases Lab, FELS Institute for Cancer Research and Molecular Biology, Philadelphia, Pennsylvania, USA
| | - Ying Wang
- Molecular Studies of Neurodegenerative Diseases Lab, FELS Institute for Cancer Research and Molecular Biology, Philadelphia, Pennsylvania, USA
| | - Sterling Arjona
- Molecular Studies of Neurodegenerative Diseases Lab, FELS Institute for Cancer Research and Molecular Biology, Philadelphia, Pennsylvania, USA
| | - Charles Allen
- Molecular Studies of Neurodegenerative Diseases Lab, FELS Institute for Cancer Research and Molecular Biology, Philadelphia, Pennsylvania, USA
| | - Bassel E Sawaya
- Department of Neurology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
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29
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Lehmann MH, Lehmann JM, Erfle V. Nef-induced CCL2 Expression Contributes to HIV/SIV Brain Invasion and Neuronal Dysfunction. Front Immunol 2019; 10:2447. [PMID: 31681324 PMCID: PMC6803470 DOI: 10.3389/fimmu.2019.02447] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/01/2019] [Indexed: 12/26/2022] Open
Abstract
C-C motif chemokine ligand 2 (CCL2) is a chemoattractant for leukocytes including monocytes, T cells, and natural killer cells and it plays an important role in maintaining the integrity and function of the brain. However, there is accumulating evidence that many neurological diseases are attributable to a dysregulation of CCL2 expression. Acquired immune deficiency syndrome (AIDS) encephalopathy is a severe and frequent complication in individuals infected with the human immunodeficiency virus (HIV) or the simian immunodeficiency virus (SIV). The HIV and SIV Nef protein, a progression factor in AIDS pathology, can be transferred by microvesicles including exosomes and tunneling nanotubes (TNT) within the host even to uninfected cells, and Nef can induce CCL2 expression. This review focuses on findings which collectively add new insights on how Nef-induced CCL2 expression contributes to neurotropism and neurovirulence of HIV and SIV and elucidates why adjuvant targeting of CCL2 could be a therapeutic option for HIV-infected persons.
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Affiliation(s)
- Michael H Lehmann
- Institute of Virology, Technische Universität München, Munich, Germany.,Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jonas M Lehmann
- Department of Informatics, Technische Universität München, Munich, Germany
| | - Volker Erfle
- Institute of Virology, Technische Universität München, Munich, Germany
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30
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Putatunda R, Ho WZ, Hu W. HIV-1 and Compromised Adult Neurogenesis: Emerging Evidence for a New Paradigm of HAND Persistence. AIDS Rev 2019; 21:11-22. [PMID: 30899112 DOI: 10.24875/aidsrev.19000003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The face of the HIV-1/AIDS pandemic has changed significantly thanks to the development of antiretroviral therapy (ART) regimens. Unfortunately, several HIV-associated comorbidities continuously occur in the clinical population, most notably HIV-associated neurocognitive disorders (HAND). While many molecular and cellular mechanisms have been characterized by describing HAND pathology (specifically neuroinflammatory insults and oxidative stress) in the ART era, compromised adult neurogenesis is emerging as a potential new mechanism. Neurogenesis is a dynamic process that generates new neurons and glial cells from neural stem cells (NSCs) and neural progenitor cells (NPCs) in specific areas of the brain. There are increasing observations that HIV-1 can productively and non-productively infect NSCs and NPCs. HIV-1 proteins and/or secondary immune/inflammatory responses impair the initial differentiation process of NSCs to NPCs, restrict neuronal lineage differentiation, and aberrantly promote astrocytic lineage differentiation. Recent studies with HIV-1 transgenic animal models demonstrate varying degrees of adult neurogenic deficits, which correlate with milder to moderate forms of neurocognitive impairments. The neurogenic dysfunction underlying HAND highlights the importance of developing potential therapeutics to restore adult neurogenic homeostasis in HIV-1 patients.
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Affiliation(s)
- Raj Putatunda
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania, USA
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
| | - Wen-Zhe Ho
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania, USA
| | - Wenhui Hu
- Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania, USA
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
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31
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Insufficient glutamine synthetase activity during synaptogenesis causes spatial memory impairment in adult mice. Sci Rep 2019; 9:252. [PMID: 30670758 PMCID: PMC6342969 DOI: 10.1038/s41598-018-36619-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 11/21/2018] [Indexed: 12/11/2022] Open
Abstract
Glutamatergic synapses constitute a major excitatory neurotransmission system and are regulated by glutamate/glutamine (Gln) cycling between neurons and astrocytes. Gln synthetase (GS) produced by astrocytes plays an important role in maintaining the cycle. However, the significance of GS during synaptogenesis has not been clarified. GS activity and expression significantly increase from postnatal day (PD) 7 to 21, and GS is expressed prior to glial fibrillary acidic protein (GFAP) and is more abundant than GFAP throughout synaptogenesis. These observations suggest that GS plays an important role in synaptogenesis. We investigated this by inhibiting GS activity in neonatal mice and assessed the consequences in adult animals. Lower expression levels of GS and GFAP were found in the CA3 region of the hippocampus but not in the CA1 region. Moreover, synaptic puncta and glutamatergic neurotransmission were also decreased in CA3. Behaviorally, mice with inhibited GS during synaptogenesis showed spatial memory-related impairment as adults. These results suggest that postnatal GS activity is important for glutamatergic synapse development in CA3.
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32
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Fernandes N, Pulliam L. Inflammatory Mechanisms and Cascades Contributing to Neurocognitive Impairment in HIV/AIDS. Curr Top Behav Neurosci 2019; 50:77-103. [PMID: 31385260 DOI: 10.1007/7854_2019_100] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Neurocognitive impairment caused by chronic human immunodeficiency virus (HIV) infection is a growing concern. In this chapter we discuss the inflammatory mechanisms underlying the pathology of asymptomatic and mild neurocognitive impairment in the context of antiretroviral therapy. We discuss the role of HIV, viral proteins, and virally infected cells on the development of neuroinflammation and the effect of viral proteins on the cells of the central nervous system.We examine how these collective factors result in an inflammatory context that triggers the development of neurocognitive impairment in HIV. We assess the contribution of antiretrovirals and drugs of abuse, including methamphetamine, cannabis, and opioids, to the neurotoxic and neuroinflammatory milieu that leads to the development of neurocognitive impairment in HIV-infected individuals. We also examined circulating biomarkers, NF-L, sCD163, and sCD14, pertinent to identifying changes in the CNS that could indicate real-time changes in patient physiology. Lastly, we discuss future studies, such as exosomes and the microbiome, which could play a role in the HIV-induced neuroinflammation that eventually manifests as cognitive impairment.
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Affiliation(s)
- Nicole Fernandes
- Department of Laboratory Medicine, San Francisco VA Health Care System, San Francisco, CA, USA.,University of California, San Francisco, San Francisco, CA, USA
| | - Lynn Pulliam
- Department of Laboratory Medicine, San Francisco VA Health Care System, San Francisco, CA, USA. .,University of California, San Francisco, San Francisco, CA, USA.
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33
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Zhou F, Liu X, Zuo D, Xue M, Gao L, Yang Y, Wang J, Niu L, Cao Q, Li X, Hua H, Zhang B, Hu M, Gao D, Zheng K, Izumiya Y, Tang R. HIV-1 Nef-induced lncRNA AK006025 regulates CXCL9/10/11 cluster gene expression in astrocytes through interaction with CBP/P300. J Neuroinflammation 2018; 15:303. [PMID: 30382871 PMCID: PMC6208068 DOI: 10.1186/s12974-018-1343-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/23/2018] [Indexed: 01/04/2023] Open
Abstract
Background HIV-associated neurocognitive disorder (HAND) is a neurodegenerative disease associated with persistent neuroinflammation and subsequent neuron damage. Pro-inflammatory factors and neurotoxins from activated astrocytes by HIV-1 itself and its encoded proteins, including the negative factor (Nef), are involved in the pathogenesis of HAND. This study was designed to find potential lncRNAs that regulate astrocyte functions and inflammation process. Methods We performed microarray analysis of lncRNAs from primary mouse astrocytes treated with Nef protein. Top ten lncRNAs were validated through real-time PCR analysis. Gene ontology (GO) and KEGG pathway analysis were applied to explore the potential functions of lncRNAs. RIP and ChIP assays were performed to demonstrate the mechanism of lncRNA regulating gene expression. Results There were 638 co-upregulated lncRNAs and 372 co-downregulated lncRNAs in primary astrocytes treated with Nef protein for both 6 h and 12 h. GO and KEGG pathway analysis showed that the biological functions of top differential-expressed mRNAs were associated with inflammatory cytokines and chemokine. Knockdown of lncRNA AK006025, not AK138360, inhibited significantly CXCL9, CXCL10 (IP-10), and CXCL11 expression in astrocytes treated with Nef protein. Mechanism study showed that AK006025 associated with CBP/P300 was enriched in the promoter of CXCL9, CXCL10, and CXCL11 genes. Conclusions Our findings uncovered the expression profiles of lncRNAs and mRNAs in vitro, which might help to understand the pathways that regulate astrocyte activation during the process of HAND. Electronic supplementary material The online version of this article (10.1186/s12974-018-1343-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Feng Zhou
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China. .,Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China.
| | - Xiaomei Liu
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Dongjiao Zuo
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Min Xue
- Department of Physiology, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Lin Gao
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Ying Yang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Jing Wang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Liping Niu
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Qianwen Cao
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Xiangyang Li
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Hui Hua
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Bo Zhang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Minmin Hu
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Dianshuai Gao
- Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Kuiyang Zheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China
| | - Yoshihiro Izumiya
- Department of Dermatology, University of California Davis (UC Davis) School of Medicine, Sacramento, CA, USA
| | - Renxian Tang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, People's Republic of China.
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Slow Release of HIV-1 Protein Nef from Vesicle-like Structures Is Inhibited by Cytosolic Calcium Elevation in Single Human Microglia. Mol Neurobiol 2018; 56:102-118. [DOI: 10.1007/s12035-018-1072-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/09/2018] [Indexed: 12/14/2022]
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35
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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 2018; 60:S169-S193. [PMID: 28800335 DOI: 10.3233/jad-170473] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [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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Lamers SL, Fogel GB, Liu ES, Barbier AE, Rodriguez CW, Singer EJ, Nolan DJ, Rose R, McGrath MS. Brain-specific HIV Nef identified in multiple patients with neurological disease. J Neurovirol 2017; 24:1-15. [PMID: 29063512 DOI: 10.1007/s13365-017-0586-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/28/2017] [Accepted: 10/03/2017] [Indexed: 12/11/2022]
Abstract
HIV-1 Nef is a flexible, multifunctional protein with several cellular targets that is required for pathogenicity of the virus. This protein maintains a high degree of genetic variation among intra- and inter-host isolates. HIV Nef is relevant to HIV-associated neurological diseases (HAND) in patients treated with combined antiretroviral therapy because of the protein's role in promoting survival and migration of infected brain macrophages. In this study, we analyzed 2020 HIV Nef sequences derived from 22 different tissues and 31 subjects using a novel computational approach. This approach combines statistical regression and evolved neural networks (ENNs) to classify brain sequences based on the physical and chemical characteristics of functional Nef domains. Based on training, testing, and validation data, the method successfully classified brain Nef sequences at 84.5% and provided informative features for further examination. These included physicochemical features associated with the Src-homology-3 binding domain, the Nef loop (including the AP-2 Binding region), and a cytokine-binding domain. Non-brain sequences from patients with HIV-associated neurological disease were frequently classified as brain, suggesting that the approach could indicate neurological risk using blood-derived virus or for the development of biomarkers for use in assay systems aimed at drug efficacy studies for the treatment of HIV-associated neurological diseases.
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Abstract
Human immunodeficiency virus (HIV) infection induces neuronal injuries, with almost 50% of infected individuals developing HIV-associated neurocognitive disorders (HAND). Although highly activate antiretroviral therapy (HAART) has significantly reduced the incidence of severe dementia, the overall prevalence of HAND remains high. Synaptic degeneration is emerging as one of the most relevant neuropathologies associate with HAND. Previous studies have reported critical roles of viral proteins and inflammatory responses in this pathogenesis. Infected cells, including macrophages, microglia and astrocytes, may release viral proteins and other neurotoxins to stimulate neurons and cause excessive calcium influx, overproduction of free radicals and disruption of neurotransmitter hemostasis. The dysregulation of neural circuits likely leads to synaptic damage and loss. Identification of the specific mechanism of the synaptic degeneration may facilitate the development of effective therapeutic approaches to treat HAND.
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Affiliation(s)
- Wenjuan Ru
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Shao-Jun Tang
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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38
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Chronic low-level expression of HIV-1 Tat promotes a neurodegenerative phenotype with aging. Sci Rep 2017; 7:7748. [PMID: 28798382 PMCID: PMC5552766 DOI: 10.1038/s41598-017-07570-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 06/28/2017] [Indexed: 12/20/2022] Open
Abstract
The widespread use of combinational antiretroviral therapies (cART) in developed countries has changed the course of Human Immunodeficiency Virus (HIV) infection from an almost universally fatal disease to a chronic infection for the majority of individuals. Although cART has reduced the severity of neurological damage in HIV-infected individuals, the likelihood of cognitive impairment increases with age, and duration of infection. As cART does not suppress the expression of HIV non-structural proteins, it has been proposed that a constitutive production of HIV regulatory proteins in infected brain cells may contribute to neurological damage. However, this assumption has never been experimentally tested. Here we take advantage of the leaky tetracycline promoter system in the Tat-transgenic mouse to show that a chronic very low-level expression of Tat is associated with astrocyte activation, inflammatory cytokine expression, ceramide accumulation, reductions in brain volume, synaptic, and axonal damage that occurs over a time frame of 1 year. These data suggest that a chronic low-level production of Tat may contribute to progressive neurological damage in virally suppressed HIV-infected individuals.
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Pužar Dominkuš P, Ferdin J, Plemenitaš A, Peterlin BM, Lenassi M. Nef is secreted in exosomes from Nef.GFP-expressing and HIV-1-infected human astrocytes. J Neurovirol 2017; 23:713-724. [PMID: 28762184 DOI: 10.1007/s13365-017-0552-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 06/16/2017] [Accepted: 07/10/2017] [Indexed: 12/16/2022]
Abstract
HIV-1 infection of the central nervous system causes HIV-associated neurocognitive disorders, even in aviremic patients. Although astrocyte malfunction was associated to these disorders, their implication is overshadowed by contributions of microglia and macrophages. Astrocytes are infected with HIV-1 in vivo and express a relevant amount of viral protein Nef. Nef was shown to stimulate its own release in exosomes from diverse cell types, which in turn have damaging effects on neighboring cells. Using immunoblotting and electron microscopy, we showed that human astrocytes expressing Nef.GFP similarly release Nef in exosomes. Importantly, Nef.GFP expression increases the secretion of exosomes from human astrocytes up to 5.5-fold, as determined by total protein content and nanoparticle tracking analysis. Protein analysis of exosomes and viruses separated on iodixanol gradient further showed that native or pseudotyped HIV-1-infected human astrocytes release exosomes, which contain Nef. Our results provide the basis for future studies of the damaging role of Nef-exosomes produced by HIV-infected astrocytes on the central nervous system.
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Affiliation(s)
- Pia Pužar Dominkuš
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Jana Ferdin
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Ana Plemenitaš
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Boris Matija Peterlin
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, California, USA
| | - Metka Lenassi
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
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40
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HIV-1 Nef is released in extracellular vesicles derived from astrocytes: evidence for Nef-mediated neurotoxicity. Cell Death Dis 2017; 8:e2542. [PMID: 28079886 PMCID: PMC5386374 DOI: 10.1038/cddis.2016.467] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/15/2016] [Accepted: 11/18/2016] [Indexed: 12/19/2022]
Abstract
Human immunodeficiency virus-associated neurological disorders (HANDs) affect the majority of AIDS patients and are a significant problem among HIV-1-infected individuals who live longer because of combined anti-retroviral therapies. HIV-1 utilizes a number of viral proteins and subsequent cytokine inductions to unleash its toxicity on neurons. Among HIV-1 viral proteins, Nef is a small protein expressed abundantly in astrocytes of HIV-1-infected brains and has been suggested to have a role in the pathogenesis of HAND. In order to explore its effect in the central nervous system, HIV-1 Nef was expressed in primary human fetal astrocytes (PHFAs) using an adenovirus. Our results revealed that HIV-1 Nef is released in extracellular vesicles (EVs) derived from PHFA cells expressing the protein. Interestingly, HIV-1 Nef release in EVs was enriched significantly when the cells were treated with autophagy activators perifosine, tomaxifen, MG-132, and autophagy inhibitors LY294002 and wortmannin suggesting a novel role of autophagy signaling in HIV-1 Nef release from astrocytes. Next, Nef-carrying EVs were purified from astrocyte cultures and neurotoxic effects on neurons were analyzed. We observed that HIV-1 Nef-containing EVs were readily taken up by neurons as demonstrated by immunocytochemistry and immunoblotting. Furthermore, treatment of neurons with Nef-carrying EVs induced oxidative stress as evidenced by a decrease in glutathione levels. To further investigate its neurotoxic effects, we expressed HIV-1 Nef in primary neurons by adenoviral transduction. Intracellular expression of HIV-1 Nef caused axonal and neurite degeneration of neurons. Furthermore, expression of HIV-1 Nef decreased the levels of phospho-tau while enhancing total tau in primary neurons. In addition, treatment of primary neurons with Nef-carrying EVs suppressed functional neuronal action potential assessed by multielectrode array studies. Collectively, these data suggested that HIV-1 Nef can be a formidable contributor to neurotoxicity along with other factors, which leads to HAND in HIV-1-infected AIDS patients.
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Affiliation(s)
- Luca Sardo
- a Department of Biological Sciences ; University of the Sciences ; Philadelphia , PA USA
| | - Sergey Iordanskiy
- b National Center for Biodefense and Infectious Diseases; George Mason University ; Manassas , VA USA
| | - Zachary Klase
- a Department of Biological Sciences ; University of the Sciences ; Philadelphia , PA USA
| | - Fatah Kashanchi
- b National Center for Biodefense and Infectious Diseases; George Mason University ; Manassas , VA USA
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42
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Matsuda K, Chen CY, Whitted S, Chertova E, Roser DJ, Wu F, Plishka RJ, Ourmanov I, Buckler-White A, Lifson JD, Strebel K, Hirsch VM. Enhanced antagonism of BST-2 by a neurovirulent SIV envelope. J Clin Invest 2016; 126:2295-307. [PMID: 27159392 PMCID: PMC4887162 DOI: 10.1172/jci83725] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 03/22/2016] [Indexed: 11/17/2022] Open
Abstract
Current antiretroviral therapy (ART) is not sufficient to completely suppress disease progression in the CNS, as indicated by the rising incidence of HIV-1-associated neurocognitive disorders (HAND) among infected individuals on ART. It is not clear why some HIV-1-infected patients develop HAND, despite effective repression of viral replication in the circulation. SIV-infected nonhuman primate models are widely used to dissect the mechanisms of viral pathogenesis in the CNS. Here, we identified 4 amino acid substitutions in the cytoplasmic tail of viral envelope glycoprotein gp41 of the neurovirulent virus SIVsm804E that enhance replication in macrophages and associate with enhanced antagonism of the host restriction factor BM stromal cell antigen 2 (BST-2). Rhesus macaques were inoculated with a variant of the parental virus SIVsmE543-3 that had been engineered to contain the 4 amino acid substitutions present in gp41 of SIVsm804E. Compared with WT virus-infected controls, animals infected with mutant virus exhibited higher viral load in cerebrospinal fluid. Together, these results are consistent with a potential role for BST-2 in the CNS microenvironment and suggest that BST-2 antagonists may serve as a possible target for countermeasures against HAND.
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Affiliation(s)
- Kenta Matsuda
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Chia-Yen Chen
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Sonya Whitted
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Elena Chertova
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - David J. Roser
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Fan Wu
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Ronald J. Plishka
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Ilnour Ourmanov
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Alicia Buckler-White
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Klaus Strebel
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Vanessa M. Hirsch
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
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Lehmann MH, Torres-Domínguez LE, Price PJR, Brandmüller C, Kirschning CJ, Sutter G. CCL2 expression is mediated by type I IFN receptor and recruits NK and T cells to the lung during MVA infection. J Leukoc Biol 2016; 99:1057-64. [DOI: 10.1189/jlb.4ma0815-376rr] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 03/01/2016] [Indexed: 12/16/2022] Open
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44
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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: 551] [Impact Index Per Article: 68.9] [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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45
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Vigorito M, Connaghan KP, Chang SL. The HIV-1 transgenic rat model of neuroHIV. Brain Behav Immun 2015; 48:336-49. [PMID: 25733103 PMCID: PMC4753047 DOI: 10.1016/j.bbi.2015.02.020] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 01/28/2023] Open
Abstract
Despite the ability of current combination anti-retroviral therapy (cART) to limit the progression of HIV-1 to AIDS, HIV-positive individuals continue to experience neuroHIV in the form of HIV-associated neurological disorders (HAND), which can range from subtle to substantial neurocognitive impairment. NeuroHIV may also influence substance use, abuse, and dependence in HIV-positive individuals. Because of the nature of the virus, variables such as mental health co-morbidities make it difficult to study the interaction between HIV and substance abuse in human populations. Several rodent models have been developed in an attempt to study the transmission and pathogenesis of the HIV-1 virus. The HIV-1 transgenic (HIV-1Tg) rat is a reliable model of neuroHIV because it mimics the condition of HIV-infected patients on cART. Research using this model supports the hypothesis that the presence of HIV-1 viral proteins in the central nervous system increases the sensitivity and susceptibility of HIV-positive individuals to substance abuse.
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Affiliation(s)
- Michael Vigorito
- Institute of NeuroImmune Pharmacology and Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
| | - Kaitlyn P Connaghan
- Institute of NeuroImmune Pharmacology and Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
| | - Sulie L Chang
- Institute of NeuroImmune Pharmacology and Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA.
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46
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Saribas AS, Khalili K, Sariyer IK. Dysregulation of autophagy by HIV-1 Nef in human astrocytes. Cell Cycle 2015; 14:2899-904. [PMID: 26176554 DOI: 10.1080/15384101.2015.1069927] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Viruses often exploit autophagy, a common cellular process of degradation of damaged proteins, organelles, and pathogens, to avoid destruction. HIV-1 dysregulates this process in several cell types by means of Nef protein. Nef is a small HIV-1 protein which is expressed abundantly in astrocytes of HIV-1-infected brains and has been suggested to have a role in the pathogenesis of HIV-Associated Neurocognitive Disorders (HAND). In order to explore its effect in the CNS with respect to autophagy, HIV-1 Nef was expressed in primary human fetal astrocytes (PHFA) using an adenovirus vector (Ad-Nef). We observed that Nef expression triggered the accumulation of autophagy markers, ATG8/LC3 and p62 (SQSMT1). Similar results were obtained with Bafilomycin A1, an autophagy inhibitor which blocks the fusion of autophagosome to lysosome. Furthermore co-expression of tandem LC3 vector (mRFP-EGFP-LC3) and Ad-Nef in these cells produced mainly yellow puncta (mRFP+, EGFP+) strongly suggesting that autophagosome fusion to lysosome is blocked in PHFA cells in the presence of Nef. Together these data indicate that HIV-1 Nef mimics Bafilomycin A1 and blocks the last step of autophagy thereby helping HIV-1 virus to avoid autophagic degradation in human astrocytes.
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Affiliation(s)
- A Sami Saribas
- a Department of Neuroscience Center for Neurovirology ; Temple University School of Medicine ; Philadelphia , PA USA
| | - Kamel Khalili
- a Department of Neuroscience Center for Neurovirology ; Temple University School of Medicine ; Philadelphia , PA USA
| | - Ilker Kudret Sariyer
- a Department of Neuroscience Center for Neurovirology ; Temple University School of Medicine ; Philadelphia , PA USA
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47
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Kesby JP, Heaton RK, Young JW, Umlauf A, Woods SP, Letendre SL, Markou A, Grant I, Semenova S. Methamphetamine Exposure Combined with HIV-1 Disease or gp120 Expression: Comparison of Learning and Executive Functions in Humans and Mice. Neuropsychopharmacology 2015; 40:1899-909. [PMID: 25652249 PMCID: PMC4839513 DOI: 10.1038/npp.2015.39] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 01/15/2015] [Accepted: 01/27/2015] [Indexed: 11/09/2022]
Abstract
Methamphetamine dependence is a common comorbid condition among people living with HIV, and may exacerbate HIV-associated neurocognitive disorders. Animal models of neuroAIDS suggest that the gp120 protein may also cause cognitive impairment. The present work evaluated the separate and combined effects of HIV/gp120 and methamphetamine on learning and executive functions in both humans and transgenic mice. Human participants were grouped by HIV serostatus (HIV+ or HIV-) and lifetime methamphetamine dependence (METH+ or METH-). A neurocognitive test battery included domain-specific assessments of learning and executive functions. Mice (gp120+ and gp120-) were exposed to either a methamphetamine binge (METH+) or saline (METH-), then tested in the attentional-set-shifting task to assess learning and executive functions. In humans, HIV status was associated with significant impairments in learning, but less so for executive functions. The frequency of learning impairments varied between groups, with the greatest impairment observed in the HIV+/METH+ group. In mice, gp120 expression was associated with impairments in learning but not reversal learning (executive component). The greatest proportion of mice that failed to complete the task was observed in the gp120+/METH+ group, suggesting greater learning impairments. Our cross-species study demonstrated that HIV in humans and gp120 in mice impaired learning, and that a history of methamphetamine exposure increased the susceptibility to HIV-associated neurocognitive deficits in both species. Finally, the similar pattern of results in both species suggest that the gp120 protein may contribute to HIV-associated learning deficits in humans.
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Affiliation(s)
- James P Kesby
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Robert K Heaton
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jared W Young
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA,Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Anya Umlauf
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Steven P Woods
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Scott L Letendre
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Athina Markou
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Igor Grant
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Svetlana Semenova
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA,Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive, M/C 0603, La Jolla, CA 92093, USA, Tel: +858 534 1528, Fax: +858 534 9917, E mail:
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48
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Liu X, Kumar A. Differential signaling mechanism for HIV-1 Nef-mediated production of IL-6 and IL-8 in human astrocytes. Sci Rep 2015; 5:9867. [PMID: 26075907 PMCID: PMC4467202 DOI: 10.1038/srep09867] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/05/2015] [Indexed: 01/01/2023] Open
Abstract
Variety of HIV-1 viral proteins including HIV-1 Nef are known to activate astrocytes and microglia in the brain and cause the release of pro-inflammatory cytokines, which is thought to be one of the mechanisms leading to HIV-1- mediated neurotoxicity. IL-6 and IL-8 have been found in the CSF of patients with HIV-1 associated dementia (HAD), suggesting that they might play important roles in HIV-1 neuropathology. In the present study we examined the effects of HIV-1 Nef on IL-6 and IL-8 induction in astrocytes. The results demonstrate that both IL-6 and IL-8 are significantly induced in HIV-1 Nef-transfected SVGA astrocytes and HIV-1 Nef-treated primary fetal astrocytes. We also determined the molecular mechanisms responsible for the HIV-1 Nef-induced increased IL-6 and IL-8 by using chemical inhibitors and siRNAs against PI3K/Akt/PKC, p38 MAPK, NF-κB, CEBP and AP-1. Our results clearly demonstrate that the PI3K/PKC, p38 MAPK, NF-κB and AP-1 pathways are involved in HIV-1 Nef-induced IL-6 production in astrocytes, while PI3K/PKC and NF-κB pathways are involved in HIV-1 Nef-induced IL-8 production. These results offer new potential targets to develop therapeutic strategy for treatment of HIV-1 associated neurological disorders, prevalent in > 40% of individuals infected with HIV-1.
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Affiliation(s)
- Xun Liu
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri, Kansas City, MO 64108
| | - Anil Kumar
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri, Kansas City, MO 64108
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49
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Hong S, Banks WA. Role of the immune system in HIV-associated neuroinflammation and neurocognitive implications. Brain Behav Immun 2015; 45:1-12. [PMID: 25449672 PMCID: PMC4342286 DOI: 10.1016/j.bbi.2014.10.008] [Citation(s) in RCA: 250] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 10/13/2014] [Accepted: 10/15/2014] [Indexed: 12/16/2022] Open
Abstract
Individuals living with HIV who are optimally treated with combination antiretroviral therapy (cART) can now lead an extended life. In spite of this remarkable survival benefit from viral suppression achieved by cART in peripheral blood, the rate of mild to moderate cognitive impairment remains high. A cognitive decline that includes impairments in attention, learning and executive function is accompanied by increased rates of mood disorders that together adversely impact the daily life of those with chronic HIV infection. The evidence is clear that cells in the brain are infected with HIV that has crossed the blood-brain barrier both as cell-free virus and within infected monocytes and T cells. Viral proteins that circulate in blood can induce brain endothelial cells to release cytokines, invoking another source of neuroinflammation. The difficulty of efficient delivery of cART to the central nervous system (CNS) contributes to elevated viral load in the CNS, resulting in a persistent HIV-associated neurocognitive disorders (HAND). The pathogenesis of HAND is multifaceted, and mounting evidence indicates that immune cells play a major role. HIV-infected monocytes and T cells not only infect brain resident cells upon migration into the CNS but also produce proinflammatory cytokines such as TNF and IL-1ß, which in turn, further activate microglia and astrocytes. These activated brain resident cells, along with perivascular macrophages, are the main contributors to neuroinflammation in HIV infection and release neurotoxic factors such as excitatory amino acids and inflammatory mediators, resulting in neuronal dysfunction and death. Cytokines, which are elevated in the blood of patients with HIV infection, may also contribute to brain inflammation by entering the brain from the blood. Host factors such as aging and co-morbid conditions such as cytomegalovirus co-infection and vascular pathology are important factors that affect the HIV-host immune interactions in HAND pathogenesis. By these diverse mechanisms, HIV-1 induces a neuroinflammatory response that is likely to be a major contributor to the cognitive and behavior changes seen in HIV infection.
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Affiliation(s)
- Suzi Hong
- Department of Psychiatry, University of California San Diego, United States.
| | - William A. Banks
- Geriatric Research Clinical and Education Center, Veterans Affairs Puget Sound Health Care System and Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine
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50
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Chagnon-Choquet J, Gauvin J, Roger J, Fontaine J, Poudrier J, Roger M. HIV Nef promotes expression of B-lymphocyte stimulator by blood dendritic cells during HIV infection in humans. J Infect Dis 2014; 211:1229-40. [PMID: 25378636 DOI: 10.1093/infdis/jiu611] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dendritic cells (DCs) modulate B-cell survival and differentiation, mainly through production of growth factors such as B lymphocyte stimulator (BLyS; also known as "B-cell factor belonging to the tumor necrosis factor family" [BAFF]). We have recently shown that, in human immunodeficiency virus (HIV)-infected individuals with rapid and those with classic disease progression, B-cell dysregulations were associated with increased BLyS expression in plasma and by blood myeloid DCs (mDCs), in contrast to aviremic HIV-infected individuals with slow disease progression (also known as "elite controllers"). In previous work with transgenic mice expressing HIV genes, B-cell dysregulations were concomitant with altered mDCs and dependent on HIV negative factor (Nef). We now report that HIV Nef is detected early after infection and despite successful therapy in plasma and BLyS-overexpressing blood mDCs of HIV-infected rapid and classic progressors, whereas it is low to undetectable in aviremic slow progressors. In vitro, HIV Nef drives monocyte-derived DCs toward BLyS overexpression through a process involving STAT1. Importantly, this is counteracted in the presence of all-trans retinoic acid. Nef thus contributes to high BLyS proinflammatory profiles in HIV-infected individuals.
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Affiliation(s)
- Josiane Chagnon-Choquet
- Laboratoire d'immunogénétique, Centre de Recherche du Centre Hospitalier Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Canada
| | - Julie Gauvin
- Laboratoire d'immunogénétique, Centre de Recherche du Centre Hospitalier Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Canada
| | - Julien Roger
- Laboratoire d'immunogénétique, Centre de Recherche du Centre Hospitalier
| | - Julie Fontaine
- Laboratoire d'immunogénétique, Centre de Recherche du Centre Hospitalier Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Canada
| | - Johanne Poudrier
- Laboratoire d'immunogénétique, Centre de Recherche du Centre Hospitalier Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Canada
| | - Michel Roger
- Laboratoire d'immunogénétique, Centre de Recherche du Centre Hospitalier Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Canada
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