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Abstract
Viruses are intracellular parasites that subvert the functions of their host cells to accomplish their infection cycle. The endoplasmic reticulum (ER)-residing chaperone proteins are central for the achievement of different steps of the viral cycle, from entry and replication to assembly and exit. The most abundant ER chaperones are GRP78 (78-kDa glucose-regulated protein), GRP94 (94-kDa glucose-regulated protein), the carbohydrate or lectin-like chaperones calnexin (CNX) and calreticulin (CRT), the protein disulfide isomerases (PDIs), and the DNAJ chaperones. This review will focus on the pleiotropic roles of ER chaperones during viral infection. We will cover their essential role in the folding and quality control of viral proteins, notably viral glycoproteins which play a major role in host cell infection. We will also describe how viruses co-opt ER chaperones at various steps of their infectious cycle but also in order to evade immune responses and avoid apoptosis. Finally, we will discuss the different molecules targeting these chaperones and the perspectives in the development of broad-spectrum antiviral drugs.
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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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Williams ME, Zulu SS, Stein DJ, Joska JA, Naudé PJW. Signatures of HIV-1 subtype B and C Tat proteins and their effects in the neuropathogenesis of HIV-associated neurocognitive impairments. Neurobiol Dis 2019; 136:104701. [PMID: 31837421 DOI: 10.1016/j.nbd.2019.104701] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/18/2019] [Accepted: 12/08/2019] [Indexed: 11/16/2022] Open
Abstract
HIV-associated neurocognitive impairments (HANI) are a spectrum of neurological disorders due to the effects of HIV-1 on the central nervous system (CNS). The HIV-1 subtypes; HIV-1 subtype B (HIV-1B) and HIV-1 subtype C (HIV-1C) are responsible for the highest prevalence of HANI and HIV infections respectively. The HIV transactivator of transcription (Tat) protein is a major contributor to the neuropathogenesis of HIV. The effects of the Tat protein on cells of the CNS is determined by the subtype-associated amino acid sequence variations. The extent to which the sequence variation between Tat-subtypes contribute to underlying mechanisms and neurological outcomes are not clear. In this review of the literature, we discuss how amino acid variations between HIV-1B Tat (TatB) and HIV-1C Tat (TatC) proteins contribute to the potential underlying neurobiological mechanisms of HANI. Tat-C is considered to be a more effective transactivator, whereas Tat-B may exert increased neurovirulence, including neuronal apoptosis, monocyte infiltration into the brain, (neuro)inflammation, oxidative stress and blood-brain barrier damage. These findings support the premise that Tat variants from different HIV-1 subtypes may direct neurovirulence and neurological outcomes in HANI.
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Affiliation(s)
- Monray E Williams
- Department of Psychiatry and Mental Health and Neuroscience Institute, Brain Behaviour Unit, University of Cape Town, Cape Town, South Africa.
| | - Simo S Zulu
- Department of Psychiatry and Mental Health and Neuroscience Institute, Brain Behaviour Unit, University of Cape Town, Cape Town, South Africa
| | - Dan J Stein
- Department of Psychiatry and Mental Health and Neuroscience Institute, Brain Behaviour Unit, University of Cape Town, Cape Town, South Africa; SAMRC Unit on Risk and Resilience in Mental Disorders and Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - John A Joska
- Division of Neuropsychiatry, Department of Psychiatry and Mental Health, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Petrus J W Naudé
- Department of Psychiatry and Mental Health and Neuroscience Institute, Brain Behaviour Unit, University of Cape Town, Cape Town, South Africa
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Ajasin DO, Rao VR, Wu X, Ramasamy S, Pujato M, Ruiz AP, Fiser A, Bresnick AR, Kalpana GV, Prasad VR. CCL2 mobilizes ALIX to facilitate Gag-p6 mediated HIV-1 virion release. eLife 2019; 8:35546. [PMID: 31172941 PMCID: PMC6592687 DOI: 10.7554/elife.35546] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 06/06/2019] [Indexed: 12/22/2022] Open
Abstract
Cellular ESCRT machinery plays pivotal role in HIV-1 budding and release. Extracellular stimuli that modulate HIV-1 egress are currently unknown. We found that CCL2 induced by HIV-1 clade B (HIV-1B) infection of macrophages enhanced virus production, while CCL2 immuno-depletion reversed this effect. Additionally, HIV-1 clade C (HIV-1C) was refractory to CCL2 levels. We show that CCL2-mediated increase in virus production requires Gag late motif LYPX present in HIV-1B, but absent in HIV-1C, and ALIX protein that recruits ESCRT III complex. CCL2 immuno-depletion sequestered ALIX to F-actin structures, while CCL2 addition mobilized it to cytoplasm facilitating Gag-ALIX binding. The LYPX motif improves virus replication and its absence renders the virus less fit. Interestingly, novel variants of HIV-1C with PYRE/PYKE tetrapeptide insertions in Gag-p6 conferred ALIX binding, CCL2-responsiveness and enhanced virus replication. These results, for the first time, indicate that CCL2 mediates ALIX mobilization from F-actin and enhances HIV-1 release and fitness.
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Affiliation(s)
- David O Ajasin
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, United States
| | - Vasudev R Rao
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, United States
| | - Xuhong Wu
- Department of Genetics, Albert Einstein College of Medicine, Bronx, United States
| | - Santhamani Ramasamy
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, United States
| | - Mario Pujato
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, United States
| | - Arthur P Ruiz
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, United States
| | - Andras Fiser
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, United States
| | - Anne R Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, United States
| | - Ganjam V Kalpana
- Department of Genetics, Albert Einstein College of Medicine, Bronx, United States
| | - Vinayaka R Prasad
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, United States
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Zhao R, Li Y, Gorantla S, Poluektova LY, Lin H, Gao F, Wang H, Zhao J, Zheng JC, Huang Y. Small molecule ONC201 inhibits HIV-1 replication in macrophages via FOXO3a and TRAIL. Antiviral Res 2019; 168:134-145. [PMID: 31158413 DOI: 10.1016/j.antiviral.2019.05.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 01/01/2023]
Abstract
Despite the success of antiretroviral therapy (ART), eradication of HIV-1 from brain reservoirs remains elusive. HIV-1 brain reservoirs include perivascular macrophages that are behind the blood-brain barrier and difficult to access by ART. Macrophages express transcription factor FOXO3a and the TNF superfamily cytokine TRAIL, which are known to target HIV-1-infected macrophages for viral inhibition. ONC201 is a novel and potent FOXO3a activator capable of inducing TRAIL. It can cross the blood-brain barrier, and has shown antitumor effects in clinical trials. We hypothesized that activation of FOXO3a/TRAIL by ONC201 will inhibit HIV-1 replication in macrophages. Using primary human monocyte-derived macrophages, we demonstrated that ONC201 dose-dependently decreased replication levels of both HIV-1 laboratory strain and primary strains as determined by HIV-1 reverse transcriptase activity assay. Consistent with data on HIV-1 replication, ONC201 also reduced intracellular and extracellular p24, viral RNA, and integrated HIV-1 DNA in infected macrophages. Blocking TRAIL or knockdown of FOXO3a with siRNA reversed ONC201-mediated HIV-1 suppression, suggesting that ONC201 inhibits HIV-1 through FOXO3a and TRAIL. The anti-HIV-1 effect of ONC201 was further validated in vivo in NOD/scid-IL-2Rgcnull mice. After intracranial injection of HIV-1-infected macrophages into the basal ganglia, we treated the mice daily with ONC201 through intraperitoneal injection for six days. ONC201 significantly decreased p24 levels in both the macrophages and the brain tissues, suggesting that ONC201 suppresses HIV-1 in vivo. Therefore, ONC201 can be a promising drug candidate to combat persistent HIV-1 infection in the brain.
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Affiliation(s)
- Runze Zhao
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Yuju Li
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States; Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Santhi Gorantla
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Larisa Y Poluektova
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Hai Lin
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States; Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Fengtong Gao
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Hongyun Wang
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Jeffrey Zhao
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Jialin C Zheng
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States; Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China.
| | - Yunlong Huang
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States; Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China.
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Liu J, Li Y, Xia X, Yang X, Zhao R, Peer J, Wang H, Tong Z, Gao F, Lin H, Wu B, Huang Y, Zheng JC. Propofol reduces microglia activation and neurotoxicity through inhibition of extracellular vesicle release. J Neuroimmunol 2019; 333:476962. [PMID: 31108401 DOI: 10.1016/j.jneuroim.2019.05.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 03/28/2019] [Accepted: 05/03/2019] [Indexed: 12/17/2022]
Abstract
Propofol is an established anesthetic widely used for induction and maintenance of anesthesia. We investigated propofol for its anti-inflammatory effects on microglia and found that propofol treatment is associated with substantial lower levels of extracellular vesicles (EVs) in immune activated microglia. Importantly, EVs collected from immune activated microglia reversed propofol-mediated anti-inflammatory and neuroprotective effects, suggesting that propofol reduces proinflammatory microglia activation and microglia-mediated neurotoxicity through inhibition of EV release. These data shed new insight into a novel molecular mechanism of propofol-mediated neuroprotective and immunomodulatory effects through inhibition of EV release.
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Affiliation(s)
- Jianhui Liu
- Department of Anesthesiology, Tongji Hospital affiliated to Tongji University School of Medicine, Shanghai, China; Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Yuju Li
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai, China; Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Xiaohuan Xia
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai, China
| | - Xiaoyu Yang
- Department of Anesthesiology, Tongji Hospital affiliated to Tongji University School of Medicine, Shanghai, China
| | - Runze Zhao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Justin Peer
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Hongyun Wang
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Zenghan Tong
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Fengtong Gao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Hai Lin
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Beiqing Wu
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Yunlong Huang
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai, China; Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States.
| | - Jialin C Zheng
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital affiliated to Tongji University School of Medicine, Shanghai, China; Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States.
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Rahimian P, He JJ. HIV/neuroAIDS biomarkers. Prog Neurobiol 2017; 157:117-132. [PMID: 27084354 PMCID: PMC5705228 DOI: 10.1016/j.pneurobio.2016.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 04/01/2016] [Accepted: 04/08/2016] [Indexed: 12/12/2022]
Abstract
HIV infection often causes neurological symptoms including cognitive and motor dysfunction, which have been collectively termed HIV/neuroAIDS. Neuropsychological assessment and clinical symptoms have been the primary diagnostic criteria for HIV/neuroAIDS, even for the mild cognitive and motor disorder, the most prevalent form of HIV/neuroAIDS in the era of combination antiretroviral therapy. Those performance-based assessments and symptoms are generally descriptive and do not have the sensitivity and specificity to monitor the diagnosis, progression, and treatment response of the disease when compared to objective and quantitative laboratory-based biological markers, or biomarkers. In addition, effects of demographics and comorbidities such as substance abuse, psychiatric disease, nutritional deficiencies, and co-infection on HIV/neuroAIDS could be more readily determined using biomarkers than using neuropsychological assessment and clinical symptoms. Thus, there have been great efforts in identification of HIV/neuroAIDS biomarkers over the past two decades. The need for reliable biomarkers of HIV/neuroAIDS is expected to increase as the HIV-infected population ages and their vulnerability to neurodegenerative diseases, particularly Alzheimer's disease increases. Currently, three classes of HIV/neuroAIDS biomarkers are being pursued to establish objective laboratory-based definitions of HIV-associated neurologic injury: cerebrospinal fluid biomarkers, blood biomarkers, and neuroimaging biomarkers. In this review, we will focus on the current knowledge in the field of HIV/neuroAIDS biomarker discovery.
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Affiliation(s)
- Pejman Rahimian
- Department of Cell Biology and Immunology, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Johnny J He
- Department of Cell Biology and Immunology, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States.
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López SN, Rodríguez-Valentín M, Rivera M, Rodríguez M, Babu M, Cubano LA, Xiong H, Wang G, Kucheryavykh L, Boukli NM. HIV-1 Gp120 clade B/C induces a GRP78 driven cytoprotective mechanism in astrocytoma. Oncotarget 2017; 8:68415-68438. [PMID: 28978127 PMCID: PMC5620267 DOI: 10.18632/oncotarget.19474] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/28/2017] [Indexed: 01/20/2023] Open
Abstract
HIV-1 clades are known to be one of the key factors implicated in modulating HIV-associated neurocognitive disorders. HIV-1 B and C clades account for the majority of HIV-1 infections, clade B being the most neuropathogenic. The mechanisms behind HIV-mediated neuropathogenesis remain the subject of active research. We hypothesized that HIV-1 gp120 clade B and C proteins may exert differential proliferation, cell survival and NeuroAIDS effects in human astrocytoma cells via the Unfolded Protein Response, an endoplasmic reticulum- based cytoprotective mechanism. The differential effect of gp120 clade B and C was evaluated using for the first time a Tandem Mass Tag isobaric labeling quantitative proteomic approach. Flow cytometry analyses were performed for cell cycle and cell death identification. Among the proteins differentiated by HIV-1 gp120 proteins figure cytoskeleton, oxidative stress, UPR markers and numerous glycolytic metabolism enzymes. Our results demonstrate that HIV-1 gp120 B induced migration, proliferative and protective responses granted by the expression of GRP78, while HIV-1 gp120 C induced the expression of key inflammatory and pro-apoptotic markers. These novel findings put forward the first evidence that GRP78 is a key player in HIV-1 clade B and C neuropathogenic discrepancies and can be used as a novel target for immunotherapies.
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Affiliation(s)
- Sheila N López
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR, USA
| | - Madeline Rodríguez-Valentín
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR, USA
| | - Mariela Rivera
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR, USA
| | - Maridaliz Rodríguez
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR, USA
| | - Mohan Babu
- Department of Biochemistry, Research and Innovation Center, University of Regina, Saskatchewan, Canada
| | - Luis A Cubano
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR, USA
| | - Huangui Xiong
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Guangdi Wang
- RCMI Cancer Research Center, Xavier University of Louisiana, New Orleans, LA, USA
| | - Lilia Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, PR, USA
| | - Nawal M Boukli
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR, USA
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Paul RH, Phillips S, Hoare J, Laidlaw DH, Cabeen R, Olbricht GR, Su Y, Stein DJ, Engelbrecht S, Seedat S, Salminen LE, Baker LM, Heaps J, Joska J. Neuroimaging abnormalities in clade C HIV are independent of Tat genetic diversity. J Neurovirol 2016; 23:319-328. [PMID: 27913960 DOI: 10.1007/s13365-016-0503-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 11/14/2016] [Accepted: 11/21/2016] [Indexed: 01/13/2023]
Abstract
Controversy remains regarding the neurotoxicity of clade C human immunodeficiency virus (HIV-C). When examined in preclinical studies, a cysteine to serine substitution in the C31 dicysteine motif of the HIV-C Tat protein (C31S) results in less severe brain injury compared to other viral clades. By contrast, patient cohort studies identify significant neuropsychological impairment among HIV-C individuals independent of Tat variability. The present study clarified this discrepancy by examining neuroimaging markers of brain integrity among HIV-C individuals with and without the Tat substitution. Thirty-seven HIV-C individuals with the Tat C31S substitution, 109 HIV-C individuals without the Tat substitution (C31C), and 34 HIV- controls underwent 3T structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Volumes were determined for the caudate, putamen, thalamus, corpus callosum, total gray matter, and total white matter. DTI metrics included fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD). Tracts of interest included the anterior thalamic radiation (ATR), cingulum bundle (CING), uncinate fasciculus (UNC), and corpus callosum (CC). HIV+ individuals exhibited smaller volumes in subcortical gray matter, total gray matter and total white matter compared to HIV- controls. HIV+ individuals also exhibited DTI abnormalities across multiple tracts compared to HIV- controls. By contrast, neither volumetric nor diffusion indices differed significantly between the Tat C31S and C31C groups. Tat C31S status is not a sufficient biomarker of HIV-related brain integrity in patient populations. Clinical attention directed at brain health is warranted for all HIV+ individuals, independent of Tat C31S or clade C status.
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Affiliation(s)
- Robert H Paul
- Missouri Institute of Mental Health, University of Missouri, St. Louis, MO, USA.
| | - Sarah Phillips
- Missouri Institute of Mental Health, University of Missouri, St. Louis, MO, USA
| | - Jacqueline Hoare
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, 7700, South Africa
| | - David H Laidlaw
- Department of Computer Science, Brown University, Providence, RI, 02912, USA
| | - Ryan Cabeen
- Department of Computer Science, Brown University, Providence, RI, 02912, USA
| | - Gayla R Olbricht
- Department of Mathematics and Statistics, Missouri University of Science and Technology, Rolla, MO, 65409, USA
| | - Yuqing Su
- Department of Mathematics and Statistics, Missouri University of Science and Technology, Rolla, MO, 65409, USA
| | - Dan J Stein
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, 7700, South Africa
| | - Susan Engelbrecht
- Division of Medical Virology, Stellenbosch University and National Health Laboratory Services (NHLS), Cape Town, South Africa
| | - Soraya Seedat
- MRC Unit on Anxiety and Stress Disorders, Department of Psychiatry, University of Stellenbosch, Stellenbosch, 7599, South Africa
| | - Lauren E Salminen
- Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, 90007, USA
| | - Laurie M Baker
- Missouri Institute of Mental Health, University of Missouri, St. Louis, MO, USA
| | - Jodi Heaps
- Missouri Institute of Mental Health, University of Missouri, St. Louis, MO, USA
| | - John Joska
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, 7700, South Africa
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The Envelope Cytoplasmic Tail of HIV-1 Subtype C Contributes to Poor Replication Capacity through Low Viral Infectivity and Cell-to-Cell Transmission. PLoS One 2016; 11:e0161596. [PMID: 27598717 PMCID: PMC5012655 DOI: 10.1371/journal.pone.0161596] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/08/2016] [Indexed: 12/15/2022] Open
Abstract
The cytoplasmic tail (gp41CT) of the HIV-1 envelope (Env) mediates Env incorporation into virions and regulates Env intracellular trafficking. Little is known about the functional impact of variability in this domain. To address this issue, we compared the replication of recombinant virus pairs carrying the full Env (Env viruses) or the Env ectodomain fused to the gp41CT of NL4.3 (EnvEC viruses) (12 subtype C and 10 subtype B pairs) in primary CD4+ T-cells and monocyte-derived-macrophages (MDMs). In CD4+ T-cells, replication was as follows: B-EnvEC = B-Env>C-EnvEC>C-Env, indicating that the gp41CT of subtype C contributes to the low replicative capacity of this subtype. In MDMs, in contrast, replication capacity was comparable for all viruses regardless of subtype and of gp41CT. In CD4+ T-cells, viral entry, viral release and viral gene expression were similar. However, infectivity of free virions and cell-to-cell transmission of C-Env viruses released by CD4+ T-cells was lower, suggestive of lower Env incorporation into virions. Subtype C matrix only minimally rescued viral replication and failed to restore infectivity of free viruses and cell-to-cell transmission. Taken together, these results show that polymorphisms in the gp41CT contribute to viral replication capacity and suggest that the number of Env spikes per virion may vary across subtypes. These findings should be taken into consideration in the design of vaccines.
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Witten JA, Thomas KGF, Westgarth-Taylor J, Joska JA. Executive Dyscontrol of Learning and Memory: Findings from a Clade C HIV-positive South African Sample. Clin Neuropsychol 2015; 29:956-84. [PMID: 26552492 DOI: 10.1080/13854046.2015.1108455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE Although pre-clinical work suggests there might be differences in neurovirulence across HIV-1 clades, few studies investigate neuropsychological deficits in the globally predominant clade C infection. The purpose of this study was to investigate verbal learning and memory performance in HIV-positive individuals in Cape Town, South Africa, where clade C is the most prevalent subtype of the virus. METHOD Using a case-control design, we recruited 53 isiXhosa-speaking, cART-naïve HIV-positive adults and 53 demographically matched HIV-negative controls. Participants were administered a comprehensive neuropsychological test battery. The test of interest was the Hopkins Verbal Learning Test-Revised (HVLT-R); previous studies have used that instrument to identify executive dyscontrol of verbal learning and memory processes in clade B HIV-positive participants. RESULTS HIV-positive participants showed only partial impairment on the HVLT-R's learning/memory components (e.g., they recalled significantly fewer words across learning trials, but displayed relatively intact performance on delayed recall trials). They also displayed little executive dyscontrol over encoding and retrieval processes (e.g., there were no significant between-group differences on measures of semantic or serial clustering). CONCLUSIONS Post-cART era studies suggest that verbal learning and memory performance is impaired in clade B samples, at least partially due to executive dyscontrol over encoding and retrieval processes. We found few such impairments in the current clade C sample. These preliminary findings suggest different CNS vulnerability across clades that would have implications for delineating clade-specific neuropathological and neurocognitive clinical features.
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Affiliation(s)
- Jade A Witten
- a ACSENT Laboratory, Department of Psychology , University of Cape Town , Cape Town , South Africa
| | - Kevin G F Thomas
- a ACSENT Laboratory, Department of Psychology , University of Cape Town , Cape Town , South Africa
| | | | - John A Joska
- b Department of Psychiatry and Mental Health , University of Cape Town , Cape Town , South Africa
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Wu B, Huang Y, Braun AL, Tong Z, Zhao R, Li Y, Liu F, Zheng JC. Glutaminase-containing microvesicles from HIV-1-infected macrophages and immune-activated microglia induce neurotoxicity. Mol Neurodegener 2015; 10:61. [PMID: 26546362 PMCID: PMC4635976 DOI: 10.1186/s13024-015-0058-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 11/02/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND HIV-1-infected and/or immune-activated microglia and macrophages are pivotal in the pathogenesis of HIV-1-associated neurocognitive disorders (HAND). Glutaminase, a metabolic enzyme that facilitates glutamate generation, is upregulated and may play a pathogenic role in HAND. Our previous studies have demonstrated that glutaminase is released to the extracellular fluid during HIV-1 infection and neuroinflammation. However, key molecular mechanisms that regulate glutaminase release remain unknown. Recent advances in understanding intercellular trafficking have identified microvesicles (MVs) as a novel means of shedding cellular contents. We posit that during HIV-1 infection and immune activation, microvesicles may mediate glutaminase release, generating excessive and neurotoxic levels of glutamate. RESULTS MVs isolated through differential centrifugation from cell-free supernatants of monocyte-derived macrophages (MDM) and BV2 microglia cell lines were first confirmed in electron microscopy and immunoblotting. As expected, we found elevated number of MVs, glutaminase immunoreactivities, as well as glutaminase enzyme activity in the supernatants of HIV-1 infected MDM and lipopolysaccharide (LPS)-activated microglia when compared with controls. The elevated glutaminase was blocked by GW4869, a neutral sphingomyelinase inhibitor known to inhibit MVs release, suggesting a critical role of MVs in mediating glutaminase release. More importantly, MVs from HIV-1-infected MDM and LPS-activated microglia induced significant neuronal injury in rat cortical neuron cultures. The MV neurotoxicity was blocked by a glutaminase inhibitor or GW4869, suggesting that the neurotoxic potential of HIV-1-infected MDM and LPS-activated microglia is dependent on the glutaminase-containing MVs. CONCLUSIONS These findings support MVs as a potential pathway/mechanism of excessive glutamate generation and neurotoxicity in HAND and therefore MVs may serve as a novel therapeutic target.
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Affiliation(s)
- Beiqing Wu
- Laboratory of Neuroimmunology and Regenerative Therapy, Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA.
| | - Yunlong Huang
- Laboratory of Neuroimmunology and Regenerative Therapy, Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA. .,Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200025, China.
| | - Alexander L Braun
- Laboratory of Neuroimmunology and Regenerative Therapy, Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA.
| | - Zenghan Tong
- Laboratory of Neuroimmunology and Regenerative Therapy, Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA.
| | - Runze Zhao
- Laboratory of Neuroimmunology and Regenerative Therapy, Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA.
| | - Yuju Li
- Laboratory of Neuroimmunology and Regenerative Therapy, Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA.,Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200025, China
| | - Fang Liu
- Laboratory of Neuroimmunology and Regenerative Therapy, Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA
| | - Jialin C Zheng
- Laboratory of Neuroimmunology and Regenerative Therapy, Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA. .,Departments of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, 68198-5930, USA. .,Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200025, China.
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Abstract
In the era of combined antiretroviral therapy (cART), HIV-associated neurocognitive disorders (HAND) account for 40 to 56% of all HIV+ cases. During the acute stage of HIV-1 infection (<6 months), the virus invades and replicates within the central nervous system (CNS). Compared to peripheral tissues, the local CNS cell population expresses distinct levels of chemokine receptors, which levels exert selective pressure on the invading virus. HIV-1 envelope (env) sequences recovered from the brains and cerebrospinal fluid (CSF) of neurocognitively impaired HIV+ subjects often display higher nucleotide variability as compared to non-impaired HIV+ subjects. Specifically, env evolution provides HIV-1 with the strategies to evade host immune response, to reduce chemokine receptor dependence, to increase co-receptor binding efficiency, and to potentiate neurotoxicity. The evolution of env within the CNS leads to changes that may result in the emergence of novel isolates with neurotoxic and neurovirulent features. However, whether specific factors of HIV-1 evolution lead to the emergence of neurovirulent and neurotropic isolates remains ill-defined. HIV-1 env evolution is an ongoing phenomenon that occurs independently of neurological and neurocognitive disease severity; thus HIV env evolution may play a pivotal and reciprocal role in the etiology of HAND. Despite the use of cART, the reactivation of latent viral reservoirs represents a clinical challenge because of the replenishment of the viral pool that may subsequently lead to persistent infection. Therefore, gaining a more complete understanding of how HIV-1 env evolves over the course of the disease should be considered for the development of future therapies aimed at controlling CNS burden, diminishing persistent viremia, and eradicating viral reservoirs. Here we review the current literature on the role of HIV-1 env evolution in the setting of HAND disease progression and on the impact of cART on the dynamics of viral evolution.
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Affiliation(s)
- Fabián J Vázquez-Santiago
- Department of Basic Sciences, Ponce Health Sciences University- School of Medicine / Ponce Research Institute, Ponce, PR 00716, USA
| | - Vanessa Rivera-Amill
- Department of Basic Sciences, Ponce Health Sciences University- School of Medicine / Ponce Research Institute, Ponce, PR 00716, USA
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Colón K, Vázquez-Santiago F, Rivera-Amill V, Delgado G, Massey SE, Wojna V, Noel RJ, Meléndez LM. HIV gp120 sequence variability associated with HAND in Hispanic Women. JOURNAL OF VIROLOGY & ANTIVIRAL RESEARCH 2015; 4. [PMID: 27358904 DOI: 10.4172/2324-8955.1000143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE HIV-1 variants with different tropisms are associated with various neuropathologies. This study intends to determine if this correlation is determined by unique viral env sequences. We hypothesize that HIV-1 envelope gene sequence changes are associated with cognition status. METHODS Viral RNA was extracted from peripheral blood mononuclear cells (PBMCs) co-cultures derived from HIV-1 infected Hispanic women that had been characterized for HIV associated neurocognitive disorders (HAND). RESULTS Analyses of the C2V4 region of HIV gp120 demonstrated that increased sequence diversity correlates with cognition status as sequences derived from subjects with normal cognition exhibited less diversity than sequences derived from subjects with cognitive impairment. In addition, differences in V3 and V4 loop charges were also noted as well as differences in the N-glycosylation of the V4 region. CONCLUSIONS Our data suggest that the genetic signature within the C2V4 region may contribute to the pathogenesis of HAND. HIV env sequence characteristics for the isolates grouped in milder forms of HAND can provide insightful information of prognostic value to assess neurocognitive status in HIV+ subjects, particularly during the era of highly prevalent milder forms of HAND.
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Affiliation(s)
- Krystal Colón
- Department of Microbiology and Medical Zoology, University of Puerto Rico Medical Sciences Campus, San Juan, PR
| | - Fabián Vázquez-Santiago
- Department of Basic Sciences, Microbiology Division, Ponce Health Sciences University-School of Medicine, Ponce Research Institute, Ponce PR
| | - Vanessa Rivera-Amill
- Department of Basic Sciences, Microbiology Division, Ponce Health Sciences University-School of Medicine, Ponce Research Institute, Ponce PR
| | | | | | - Valerie Wojna
- Specialized NeuroAIDS Program, University of Puerto Rico-Medical Sciences Campus, San Juan, PR, 00936, USA; Department of Internal Medicine, Neurology Division, University of Puerto Rico-Medical Sciences Campus, San Juan, PR 00936, USA
| | - Richard J Noel
- Department of Basic Sciences, Biochemistry Division, Ponce Health Sciences University-School of Medicine, Ponce Research Institute, Ponce PR
| | - Loyda M Meléndez
- Department of Microbiology and Medical Zoology, University of Puerto Rico Medical Sciences Campus, San Juan, PR
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15
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Paul RH, Joska JA, Woods C, Seedat S, Engelbrecht S, Hoare J, Heaps J, Valcour V, Ances B, Baker LM, Salminen LE, Stein DJ. Impact of the HIV Tat C30C31S dicysteine substitution on neuropsychological function in patients with clade C disease. J Neurovirol 2014; 20:627-35. [PMID: 25366660 DOI: 10.1007/s13365-014-0293-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/25/2014] [Accepted: 09/18/2014] [Indexed: 01/31/2023]
Abstract
Previous animal studies have identified a C31S residue substitution in the C30C31 dicysteine motif of the Tat protein that is associated with reduced neurovirulence in clade C human immunodeficiency virus (HIV). However, clinical studies of patients infected with clade C HIV have reported significant levels of cognitive impairment. To date, no study has specifically examined cognitive function in clade C-infected patients as a function of the presence or absence of the Tat C31 substitution. The present study investigated the impact of the Tat C30C31S genetic substitution among individuals residing in South Africa infected with clade C HIV that either exhibited the C30C31 motif (n = 128) or the C31S motif (n = 46). A control group of seronegative individuals was included to examine the overall impact of HIV on cognitive performance. All individuals completed a comprehensive neuropsychological battery consisting of tests sensitive to HIV. Results revealed that clade C-infected individuals performed significantly worse across cognitive tests compared to seronegative controls. However, there were no significant differences in cognitive performances between individuals with the C31S motif versus those without the C31S substitution. Proximal CD4 cell count and plasma viral load were unrelated to cognitive performances for either group. Results confirm that the C31S dicysteine motif substitution of the Tat protein does not appreciably moderate neuropsychological outcomes in clade C. Further, these findings highlight the importance of clinical management of cognitive symptoms among individuals infected with this viral clade worldwide.
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Affiliation(s)
- Robert H Paul
- Department of Psychology and Behavioral Neuroscience, University of Missouri-St. Louis, University Boulevard, St. Louis, USA,
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Ortega M, Heaps JM, Joska J, Vaida F, Seedat S, Stein DJ, Paul R, Ances BM. HIV clades B and C are associated with reduced brain volumetrics. J Neurovirol 2014; 19:479-87. [PMID: 24078556 DOI: 10.1007/s13365-013-0202-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 07/08/2013] [Accepted: 08/20/2013] [Indexed: 12/16/2022]
Abstract
The human immunodeficiency virus (HIV) has multiple genetic clades with varying prevalence throughout the world. Both HIV clade C (HIV-C) and HIV clade B (HIV-B) can cause cognitive impairment, but it is unclear if these clades are characterized by similar patterns of brain dysfunction. We examined brain volumetrics and neuropsychological performance among highly active antiretroviral therapy (HAART)-naïve HIV-B and HIV-C participants. Thirty-four HAART-naïve HIV-infected (HIV+) participants [17 HIV-B (USA); 17 HIV-C (South Africa)] and 34 age- and education-matched HIV-uninfected (HIV−) participants were evaluated. All participants underwent similar laboratory, neuropsychological, and neuroimaging studies. Brain volume measures were assessed within the caudate, putamen, amygdala, thalamus, hippocampus, corpus callosum, and cortical (gray and white matter) structures. A linear model that included HIV status, region, and their interaction assessed the effects of the virus on brain volumetrics. HIV− and HIV+ individuals were similar in age. On laboratory examination, HIV-C participants had lower CD4 cell counts and higher plasma HIV viral loads than HIV-B individuals. In general, HIV+ participants performed significantly worse on neuropsychological measures of processing speed and memory and had significantly smaller relative volumetrics within the thalamus, hippocampus, corpus callosum, and cortical gray and white matter compared to the respective HIV− controls. Both HIV-B and HIV-C are associated with similar volumetric declines when compared to matched HIV− controls. HIV-B and HIV-C were associated with significant reductions in brain volumetrics and poorer neuropsychological performance; however, no specific effect of HIV clade subtype was evident. These findings suggest that HIV-B and HIV-C both detrimentally affect brain integrity.
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Ragupathy V, Devadas K, Tang S, Wood O, Lee S, Dastyer A, Wang X, Dayton A, Hewlett I. Effect of sex steroid hormones on replication and transmission of major HIV subtypes. J Steroid Biochem Mol Biol 2013; 138:63-71. [PMID: 23542659 DOI: 10.1016/j.jsbmb.2013.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 02/26/2013] [Accepted: 03/01/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND The HIV epidemic is expanding worldwide with an increasing number of distinct viral subtypes and circulating recombinant forms (CRFs). Out of 34 million adults living with HIV and AIDS, women account for one half of all HIV-1 infections worldwide. These gender differences in HIV pathogenesis may be attributed to sex hormones. Little is known about the role of sex hormone effects on HIV Subtypes pathogenesis. The aim of our study was to determine sex hormone effects on replication and transmissibility of HIV subtypes. METHODS Peripheral blood mononuclear cells (PBMC) and monocyte derived dendritic cells (MDDC) from male and female donors were infected with HIV subtypes A-D and CRF02_AG, CRF01_AE, MN (lab adapted), Group-O, Group-N and HIV-2 at a concentration of 5ng/ml of p24 or p27. Virus production was evaluated by measuring p24 and p27 levels in culture supernatants. Similar experiments were carried out in the presence of physiological concentrations of sex steroid hormones. R5/X4 expressions measured by flow cytometry and transmissibility was evaluated by transfer of HIV from primary dendritic cells (DC) to autologous donor PBMC. RESULTS Our results from primary PBMC and MDDC from male and female donors indicate in the absence of physiological concentrations of hormone treatment virus production was observed in three clusters; high replicating virus (subtype B and C), moderate replicative virus (subtype A, D, CRF01_AE, Group_N) and least replicative virus (strain MN). However, dose of sex steroid hormone treatment influenced HIV replication and transmission kinetics in PBMC, DCs and cell lines. Such effects were inconsistent between donors and HIV subtypes. Sex hormone effects on HIV entry receptors (CCR5/CXCR4) did not correlate with virus production. CONCLUSIONS Subtypes B and C showed higher replication in PBMC from males and females and were transmitted more efficiently through DC to male and female PBMC compared with other HIV-1 subtypes, HIV-1 Group O and HIV-2. These findings are consistent with increased worldwide prevalence of subtype B and C compared to other subtypes. Sex steroid hormones had variable effect on replication or transmission of different subtypes. These findings suggest that subtype, gender and sex hormones may play a crucial role in the replication and transmission of HIV.
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Affiliation(s)
- Viswanath Ragupathy
- Laboratory of Molecular Virology, Division of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
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18
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STAT1 regulates human glutaminase 1 promoter activity through multiple binding sites in HIV-1 infected macrophages. PLoS One 2013; 8:e76581. [PMID: 24086752 PMCID: PMC3782442 DOI: 10.1371/journal.pone.0076581] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 08/25/2013] [Indexed: 01/14/2023] Open
Abstract
Mononuclear phagocytes (MP, macrophages and microglia), the main targets of HIV-1 infection in the brain, play a pathogenic role in HIV-associated neurocognitive disorders (HAND) through the production and release of various soluble neurotoxic factors including glutamate. We have previously reported that glutaminase (GLS), the glutamate-generating enzyme, is upregulated in HIV-1 infected MP and in the brain tissues of HIV dementia individuals, and that HIV-1 or interferon-α (IFN-α) regulates human glutaminase 1 (GLS1) promoter through signal transducer and activator of transcription 1 (STAT1) phosphorylation in macrophages. However, there are multiple putative STAT1 binding sites in human GLS1 promoter, the exact molecular mechanism of how HIV-1 or IFN-α regulates human GLS1 promoter remains unclear. To further study the function of the putative STAT1 binding sites, we mutated the sequence of each binding site to ACTAGTCTC and found that six mutants (mut 1,3,4,5,7,8) had significantly higher promoter activity and two mutants (mut 2 and mut 6) completely lost the promoter activity compared with the wild type. To determine whether sites 2 and 6 could interfere with other inhibitory sites, particularly the nearby inhibitory sites 3 and 5, we made double mutants dmut 2/3 and dmut 5/6, and found that both the double mutants had significantly higher activity than the wild type, indicating that sites 3 and 5 are critical inhibitory elements, while sites 2 and 6 are excitatory elements. ChIP assay verified that STAT1 could bind with sites 2/3 and 5/6 within human GLS1 promoter in IFN-α stimulated or HIV-1-infected monocyte-derived macrophages. Interestingly, we found that rat Gls1 promoter was regulated through a similar way as human GLS1 promoter. Together, our data identified critical elements that regulate GLS1 promoter activity.
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Ye L, Huang Y, Zhao L, Li Y, Sun L, Zhou Y, Qian G, Zheng JC. IL-1β and TNF-α induce neurotoxicity through glutamate production: a potential role for neuronal glutaminase. J Neurochem 2013; 125:897-908. [PMID: 23578284 DOI: 10.1111/jnc.12263] [Citation(s) in RCA: 246] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 02/06/2013] [Accepted: 04/09/2013] [Indexed: 01/09/2023]
Abstract
Glutaminase 1 is the main enzyme responsible for glutamate production in mammalian cells. The roles of macrophage and microglia glutaminases in brain injury, infection, and inflammation are well documented. However, little is known about the regulation of neuronal glutaminase, despite neurons being a predominant cell type of glutaminase expression. Using primary rat and human neuronal cultures, we confirmed that interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), two pro-inflammatory cytokines that are typically elevated in neurodegenerative disease states, induced neuronal death and apoptosis in vitro. Furthermore, both intracellular and extracellular glutamate levels were significantly elevated following IL-1β and/or TNF-α treatment. Pre-treatment with N-Methyl-D-aspartate (NMDA) receptor antagonist MK-801 blocked cytokine-induced glutamate production and alleviated the neurotoxicity, indicating that IL-1β and/or TNF-α induce neurotoxicity through glutamate. To determine the potential source of excess glutamate production in the culture during inflammation, we investigated the neuronal glutaminase and found that treatment with IL-1β or TNF-α significantly upregulated the kidney-type glutaminase (KGA), a glutaminase 1 isoform, in primary human neurons. The up-regulation of neuronal glutaminase was also demonstrated in situ in a murine model of HIV-1 encephalitis. In addition, IL-1β or TNF-α treatment increased the levels of KGA in cytosol and TNF-α specifically increased KGA levels in the extracellular fluid, away from its main residence in mitochondria. Together, these findings support neuronal glutaminase as a potential component of neurotoxicity during inflammation and that modulation of glutaminase may provide therapeutic avenues for neurodegenerative diseases.
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Affiliation(s)
- Ling Ye
- Department of Biochemistry and Molecular Biology, Shanghai Jiaotong University School of Medicine, Shanghai, China
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20
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Human synaptic plasticity gene expression profile and dendritic spine density changes in HIV-infected human CNS cells: role in HIV-associated neurocognitive disorders (HAND). PLoS One 2013; 8:e61399. [PMID: 23620748 PMCID: PMC3631205 DOI: 10.1371/journal.pone.0061399] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 03/08/2013] [Indexed: 11/19/2022] Open
Abstract
HIV-associated neurocognitive disorders (HAND) is characterized by development of cognitive, behavioral and motor abnormalities, and occur in approximately 50% of HIV infected individuals. Our current understanding of HAND emanates mainly from HIV-1 subtype B (clade B), which is prevalent in USA and Western countries. However very little information is available on neuropathogenesis of HIV-1 subtype C (clade C) that exists in Sub-Saharan Africa and Asia. Therefore, studies to identify specific neuropathogenic mechanisms associated with HAND are worth pursuing to dissect the mechanisms underlying this modulation and to prevent HAND particularly in clade B infection. In this study, we have investigated 84 key human synaptic plasticity genes differential expression profile in clade B and clade C infected primary human astrocytes by using RT(2) Profile PCR Array human Synaptic Plasticity kit. Among these, 31 and 21 synaptic genes were significantly (≥3 fold) down-regulated and 5 genes were significantly (≥3 fold) up-regulated in clade B and clade C infected cells, respectively compared to the uninfected control astrocytes. In flow-cytometry analysis, down-regulation of postsynaptic density and dendrite spine morphology regulatory proteins (ARC, NMDAR1 and GRM1) was confirmed in both clade B and C infected primary human astrocytes and SK-N-MC neuroblastoma cells. Further, spine density and dendrite morphology changes by confocal microscopic analysis indicates significantly decreased spine density, loss of spines and decreased dendrite diameter, total dendrite and spine area in clade B infected SK-N-MC neuroblastoma cells compared to uninfected and clade C infected cells. We have also observed that, in clade B infected astrocytes, induction of apoptosis was significantly higher than in the clade C infected astrocytes. In conclusion, this study suggests that down-regulation of synaptic plasticity genes, decreased dendritic spine density and induction of apoptosis in astrocytes may contribute to the severe neuropathogenesis in clade B infection.
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Human immunodeficiency virus type 1 (HIV-1) transactivator of transcription through its intact core and cysteine-rich domains inhibits Wnt/β-catenin signaling in astrocytes: relevance to HIV neuropathogenesis. J Neurosci 2013; 32:16306-13. [PMID: 23152614 DOI: 10.1523/jneurosci.3145-12.2012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Wnt/β-catenin is a neuroprotective pathway regulating cell fate commitment in the CNS and many vital functions of neurons and glia. Its dysregulation is linked to a number of neurodegenerative diseases. Wnt/β-catenin is also a repressor of HIV transcription in multiple cell types, including astrocytes, which are dysregulated in HIV-associated neurocognitive disorder. Given that HIV proteins can overcome host restriction factors and that perturbations of Wnt/β-catenin signaling can compromise astrocyte function, we evaluated the impact of HIV transactivator of transcription (Tat) on Wnt/β-catenin signaling in astrocytes. HIV clade B Tat, in primary progenitor-derived astrocytes and U87MG cells, inhibited Wnt/β-catenin signaling as demonstrated by its inhibition of active β-catenin, TOPflash reporter activity, and Axin-2 (a downstream target of Wnt/β-catenin signaling). Point mutations in either the core region (K41A) or the cysteine-rich region (C30G) of Tat abrogated its ability to inhibit β-catenin signaling. Clade C Tat, which lacks the dicysteine motif, did not alter β-catenin signaling, confirming that the dicysteine motif is critical for Tat inhibition of β-catenin signaling. Tat coprecipitated with TCF-4 (a transcription factor that partners with β-catenin), suggesting a physical interaction between these two proteins. Furthermore, knockdown of β-catenin or TCF-4 enhanced docking of Tat at the TAR region of the HIV long terminal repeat. These findings highlight a bidirectional interference between Tat and Wnt/β-catenin that negatively impacts their cognate target genes. The consequences of this interaction include alleviation of Wnt/β-catenin-mediated suppression of HIV and possible astrocyte dysregulation contributing to HIV neuropathogenesis.
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Peng F, Yao H, Akturk HK, Buch S. Platelet-derived growth factor CC-mediated neuroprotection against HIV Tat involves TRPC-mediated inactivation of GSK 3beta. PLoS One 2012; 7:e47572. [PMID: 23077641 PMCID: PMC3471979 DOI: 10.1371/journal.pone.0047572] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 09/17/2012] [Indexed: 12/14/2022] Open
Abstract
Platelet-derived growth factor-CC (PDGF-CC) is the third member of the PDGF family, and has been implicated both in embryogenesis and development of the CNS. The biological function of this isoform however, remains largely unexplored in the context of HIV-associated dementia (HAD). In the present study, we demonstrate that exposure of human neuroblastoma cells SH-SY5Y to HIV transactivator protein Tat resulted in decreased intrinsic expression of PDGF-CC as evidenced by RT-PCR and western blot assays. Reciprocally, pretreatment of SH-SY5Y cells with PDGF-CC abrogated Tat-mediated neurotoxicity by mitigating apoptosis and neurite & MAP-2 loss. Using pharmacological and loss of function approaches we identified the role of phosphatidylinositol 3-kinase (PI3K)/Akt signaling in PDGF-CC-mediated neuroprotection. We report herein a novel role about the involvement of transient receptor potential canonical (TRPC) channel 1 in modulation of calcium transients in PDGF-CC-mediated neuroprotection. Furthermore we also demonstrated PDGF-CC-mediated inactivation of the downstream mediator - glycogen synthase kinase 3β (GSK3β) evidenced by its phosphorylation at Ser-9. This was further validated by gain and loss of function studies using cells transfected with either the wild type or mutant GSK3β constructs. Intriguingly, pretreatment of cells with either the PI3K inhibitor or TRPC blocker resulted in failure of PDGF-CC to inactivate GSK3β, thereby suggesting the intersection of PI3K and TRPC signaling at GSK3β. Taken together our findings lead to the suggestion that PDGF-CC could be developed as a therapeutic target to reverse Tat-mediated neurotoxicity with implications for HAD.
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Affiliation(s)
- Fuwang Peng
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Honghong Yao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Halis Kaan Akturk
- Department of Medicine, Creighton Medical Center, Omaha, Nebraska, United States of America
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail:
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Mameli G, Poddighe L, Mei A, Uleri E, Sotgiu S, Serra C, Manetti R, Dolei A. Expression and activation by Epstein Barr virus of human endogenous retroviruses-W in blood cells and astrocytes: inference for multiple sclerosis. PLoS One 2012; 7:e44991. [PMID: 23028727 PMCID: PMC3459916 DOI: 10.1371/journal.pone.0044991] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 08/15/2012] [Indexed: 11/20/2022] Open
Abstract
Background Proposed co-factors triggering the pathogenesis of multiple sclerosis (MS) are the Epstein Barr virus (EBV), and the potentially neuropathogenic MSRV (MS-associated retrovirus) and syncytin-1, of the W family of human endogenous retroviruses. Methodology/Principal Findings In search of links, the expression of HERV-W/MSRV/syncytin-1, with/without exposure to EBV or to EBV glycoprotein350 (EBVgp350), was studied on peripheral blood mononuclear cells (PBMC) from healthy volunteers and MS patients, and on astrocytes, by discriminatory env-specific RT-PCR assays, and by flow cytometry. Basal expression of HERV-W/MSRV/syncytin-1 occurs in astrocytes and in monocytes, NK, and B, but not in T cells. This uneven expression is amplified in untreated MS patients, and dramatically reduced during therapy. In astrocytes, EBVgp350 stimulates the expression of HERV-W/MSRV/syncytin-1, with requirement of the NF-κB pathway. In EBVgp350-treated PBMC, MSRVenv and syncytin-1 transcription is activated in B cells and monocytes, but not in T cells, nor in the highly expressing NK cells. The latter cells, but not the T cells, are activated by proinflammatory cytokines. Conclusions/Significance In vitro EBV activates the potentially immunopathogenic and neuropathogenic HERV-W/MSRV/syncytin-1, in cells deriving from blood and brain. In vivo, pathogenic outcomes would depend on abnormal situations, as in late EBV primary infection, that is often symptomatic, or/and in the presence of particular host genetic backgrounds. In the blood, HERV-Wenv activation might induce immunopathogenic phenomena linked to its superantigenic properties. In the brain, toxic mechanisms against oligodendrocytes could be established, inducing inflammation, demyelination and axonal damage. Local stimulation by proinflammatory cytokines and other factors might activate further HERV-Ws, contributing to the neuropathogenity. In MS pathogenesis, a possible model could include EBV as initial trigger of future MS, years later, and HERV-W/MSRV/syncytin-1 as actual contributor to MS pathogenicity, in striking parallelism with disease behaviour.
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Affiliation(s)
- Giuseppe Mameli
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Luciana Poddighe
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Alessandra Mei
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Elena Uleri
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Stefano Sotgiu
- Department of Neurosciences and MIS, University of Sassari, Sassari, Italy
| | - Caterina Serra
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Roberto Manetti
- Department of Clinical, Experimental and Oncological Medicine, University of Sassari, Sassari, Italy
| | - Antonina Dolei
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
- * E-mail:
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Neuroimaging markers of human immunodeficiency virus infection in South Africa. J Neurovirol 2012; 18:151-6. [PMID: 22528474 DOI: 10.1007/s13365-012-0090-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 02/28/2012] [Accepted: 03/07/2012] [Indexed: 12/13/2022]
Abstract
Previous studies have reported cognitive deficits among HIV-positive individuals infected with clade C virus. However, no study has examined whether individuals predominately infected with clade C virus exhibit brain atrophy relative to healthy controls. This study examined volumetric differences between 28 HIV+ individuals and 23 HIV- controls from South Africa. Volumetric measures were obtained from six regions of interest -- caudate, thalamus, corpus callosum, total cortex, total gray matter, and total white matter. HIV+ participants had significantly lower volumes in the total white matter (p<0.01), thalamus (p<0.01) and total gray matter (inclusive of cortical and subcortical regions, p<0.01). This study is the first to provide evidence of brain atrophy among HIV+ individuals in South Africa, where HIV clade C predominates. Additional research that integrates neuroimaging, comprehensive neuropsychological testing, genetic variance in clade-specific proteins, and the impact of treatment with Antiretrovirals (ARV) are necessary to understand the development of HIV-related neurocognitive disorders in South Africa.
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Zhao L, Huang Y, Tian C, Taylor L, Curthoys N, Wang Y, Vernon H, Zheng J. Interferon-α regulates glutaminase 1 promoter through STAT1 phosphorylation: relevance to HIV-1 associated neurocognitive disorders. PLoS One 2012; 7:e32995. [PMID: 22479354 PMCID: PMC3316554 DOI: 10.1371/journal.pone.0032995] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 02/03/2012] [Indexed: 01/14/2023] Open
Abstract
HIV-1 associated neurocognitive disorders (HAND) develop during progressive HIV-1 infection and affect up to 50% of infected individuals. Activated microglia and macrophages are critical cell populations that are involved in the pathogenesis of HAND, which is specifically related to the production and release of various soluble neurotoxic factors including glutamate. In the central nervous system (CNS), glutamate is typically derived from glutamine by mitochondrial enzyme glutaminase. Our previous study has shown that glutaminase is upregulated in HIV-1 infected monocyte-derived-macrophages (MDM) and microglia. However, how HIV-1 leads to glutaminase upregulation, or how glutaminase expression is regulated in general, remains unclear. In this study, using a dual-luciferase reporter assay system, we demonstrated that interferon (IFN) α specifically activated the glutaminase 1 (GLS1) promoter. Furthermore, IFN-α treatment increased signal transducer and activator of transcription 1 (STAT1) phosphorylation and glutaminase mRNA and protein levels. IFN-α stimulation of GLS1 promoter activity correlated to STAT1 phosphorylation and was reduced by fludarabine, a chemical that inhibits STAT1 phosphorylation. Interestingly, STAT1 was found to directly bind to the GLS1 promoter in MDM, an effect that was dependent on STAT1 phosphorylation and significantly enhanced by IFN-α treatment. More importantly, HIV-1 infection increased STAT1 phosphorylation and STAT1 binding to the GLS1 promoter, which was associated with increased glutamate levels. The clinical relevance of these findings was further corroborated with investigation of post-mortem brain tissues. The glutaminase C (GAC, one isoform of GLS1) mRNA levels in HIV associated-dementia (HAD) individuals correlate with STAT1 (p<0.01), IFN-α (p<0.05) and IFN-β (p<0.01). Together, these data indicate that both HIV-1 infection and IFN-α treatment increase glutaminase expression through STAT1 phosphorylation and by binding to the GLS1 promoter. Since glutaminase is a potential component of elevated glutamate production during the pathogenesis of HAND, our data will help to identify additional therapeutic targets for the treatment of HAND.
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Affiliation(s)
- Lixia Zhao
- Laboratory of Neuroimmunology and Regenerative Therapy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Yunlong Huang
- Laboratory of Neuroimmunology and Regenerative Therapy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail: (JZ); (YH)
| | - Changhai Tian
- Laboratory of Neuroimmunology and Regenerative Therapy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Lynn Taylor
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Norman Curthoys
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Yi Wang
- Laboratory of Neuroimmunology and Regenerative Therapy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Hamilton Vernon
- Laboratory of Neuroimmunology and Regenerative Therapy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Jialin Zheng
- Laboratory of Neuroimmunology and Regenerative Therapy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Departments of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail: (JZ); (YH)
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Glutaminase dysregulation in HIV-1-infected human microglia mediates neurotoxicity: relevant to HIV-1-associated neurocognitive disorders. J Neurosci 2011; 31:15195-204. [PMID: 22016553 DOI: 10.1523/jneurosci.2051-11.2011] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Microglia represent the main cellular targets of HIV-1 in the brain. Infected and/or activated microglia play a pathogenic role in HIV-associated neurocognitive disorders (HAND) by instigating primary dysfunction and subsequent death of neurons. Although microglia are known to secrete neurotoxins when infected with HIV-1, the detailed mechanism of neurotoxicity remains unclear. Using a human microglia primary culture system and macrophage-tropic HIV-1 strains, we have now demonstrated that HIV-1 infection of microglia resulted in a significant increase in extracellular glutamate concentrations and elevated levels of neurotoxicity. RNA and protein analysis revealed upregulation of the glutamate-generating enzyme glutaminase isoform glutaminase C in HIV-1-infected microglia. The clinical relevance of these findings was further corroborated with investigation of postmortem brain tissues. The glutaminase C levels in the brain tissues of HIV dementia individuals were significantly higher than HIV serum-negative control and correlated with elevated concentrations of glutamate. When glutaminase was subsequently inhibited by siRNA or by a small molecular inhibitor, the HIV-induced glutamate production and the neuronal loss was diminished. In conclusion, these findings support glutaminase as a potential component of the HAND pathogenic process as well as a novel therapeutic target in their treatment.
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