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Wenzel ED, Avdoshina V, Mocchetti I. HIV-associated neurodegeneration: exploitation of the neuronal cytoskeleton. J Neurovirol 2019; 25:301-312. [PMID: 30850975 DOI: 10.1007/s13365-019-00737-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/16/2019] [Accepted: 02/18/2019] [Indexed: 01/23/2023]
Abstract
Human immunodeficiency virus-1 (HIV) infection of the central nervous system damages synapses and promotes axonal injury, ultimately resulting in HIV-associated neurocognitive disorders (HAND). The mechanisms through which HIV causes damage to neurons are still under investigation. The cytoskeleton and associated proteins are fundamental for axonal and dendritic integrity. In this article, we review evidence that HIV proteins, such as the envelope protein gp120 and transactivator of transcription (Tat), impair the structure and function of the neuronal cytoskeleton. Investigation into the effects of viral proteins on the neuronal cytoskeleton may provide a better understanding of HIV neurotoxicity and suggest new avenues for additional therapies.
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Affiliation(s)
- Erin D Wenzel
- Department of Pharmacology & Physiology, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA
| | - Valeria Avdoshina
- Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA
| | - Italo Mocchetti
- Department of Pharmacology & Physiology, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA. .,Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA.
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2
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Fingolimod induces neuronal-specific gene expression with potential neuroprotective outcomes in maturing neuronal progenitor cells exposed to HIV. J Neurovirol 2017; 23:808-824. [PMID: 28913617 PMCID: PMC5725524 DOI: 10.1007/s13365-017-0571-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 07/24/2017] [Accepted: 08/21/2017] [Indexed: 12/13/2022]
Abstract
Fingolimod (FTY720), a structural analogue of sphingosine, targets sphingosine-1-phosphate receptor signaling and is currently an immunomodulatory therapy for multiple sclerosis. Fingolimod accesses the central nervous system (CNS) where its active metabolite, fingolimod phosphate (FTY720-P), has pleotropic neuroprotective effects in an inflammatory microenvironment. To investigate potential neuronal-specific mechanisms of fingolimod neuroprotection, we cultured the human neuronal progenitor cell line, hNP1, in differentiation medium supplemented with HIV- or Mock-infected supernatants, with or without FTY720-P. Gene expression was investigated using microarray and functional genomics. FTY720-P treatment increased differentially expressed (DE) neuronal genes by 33% in HIV-exposed and 40% in Mock-exposed cultures. FTY720-P treatment broadened the functional profile of DE genes in HIV-exposed versus Mock-exposed neurons, including not only immune responses but also transcriptional regulation and cell differentiation, among others. FTY720-P treatment downregulated the gene for follistatin, the antagonist of activin signaling, in all culture conditions. FTY720-P treatment differentially affected both glycolysis-related and immune response genes in Mock- or HIV-exposed cultures, significantly upregulating 11 glycolysis-related genes in HIV-exposed neurons. FTY720-P treatment also differentially upregulated genes related to innate immune responses and antigen presentation in Mock-exposed and more so in HIV-exposed neurons. However, in HIV-exposed neurons, FTY720-P depressed the magnitude of differential expression in almost half the genes, suggesting an anti-inflammatory potential. Moreover, in HIV-exposed neurons, FTY720-P reduced expression of the amyloid precursor protein (APP) gene, resulting in reduced expression of the APP protein. This study provides new evidence that fingolimod alters neuronal gene expression in inflammatory, viral-infected microenvironments, with the potential for neuroprotective effects.
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Geffin R, Martinez R, de Las Pozas A, Issac B, McCarthy M. Apolipoprotein E4 Suppresses Neuronal-Specific Gene Expression in Maturing Neuronal Progenitor Cells Exposed to HIV. J Neuroimmune Pharmacol 2017; 12:462-483. [PMID: 28321820 PMCID: PMC5527073 DOI: 10.1007/s11481-017-9734-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/21/2017] [Indexed: 12/14/2022]
Abstract
The apolipoprotein ε4 gene allele and the apolipoprotein E4 protein (ApoE4) are important host susceptibility factors linked to neurocognitive disorders associated with HIV infection or Alzheimer’s disease. Our previous studies showed differential effects of the two most common human ApoE genotypes, APOE3/3 and APOE3/4, on gene expression by differentiating human neuroepithelial progenitor cells continuously exposed to HIV. To investigate the effects of ApoE3 versus ApoE4 isoforms specifically on maturing neurons, we adapted a human neuronal progenitor cell line, hNP1, with ApoE genotype APOE3/3. Differentiating hNP1 cells were exposed for 16 days to HIV- or mock-infected supernatants and to added recombinant ApoE isoforms rApoE3 or rApoE4 to modulate the ApoE phenotype of the cells. Gene expression was investigated using microarray and functional genomics analyses. Added rApoE3 differentially affected 36 genes. Added rApoE4 differentially affected 85 genes; 41 of which were differentially expressed only in HIV or mock-supernatant treated cells, and 80% of which were downregulated. Genes differentially downregulated only by rApoE4 represented multiple neuronal functions related to neurogenesis. Approximately five times more genes were differentially enriched by rApoE4 versus rApoE3 in the Gene Ontology (GO) cellular process analysis, with 4 orders of magnitude greater significance. Half of the top 10 GO processes affected by rApoE4 treatment were neurogenesis-related. The largest differences in gene expression between the two isoforms were observed within the HIV-exposed cultures, suggesting that HIV exposure magnifies ApoE4’s suppressive effect on neuronal gene expression. This study provides evidence for neuronal-specific responses to ApoE4 that could affect neurogenesis and neuronal survival.
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Affiliation(s)
- Rebeca Geffin
- Bruce W. Carter Veterans Affairs Medical Center, 1201 NW 16th Street, Miami, FL, 33125, USA.,Department of Neurology, Miller School of Medicine, University of Miami, 1120 NW 14th St, Miami, FL, 33136, USA
| | - Ricardo Martinez
- Bruce W. Carter Veterans Affairs Medical Center, 1201 NW 16th Street, Miami, FL, 33125, USA
| | - Alicia de Las Pozas
- Bruce W. Carter Veterans Affairs Medical Center, 1201 NW 16th Street, Miami, FL, 33125, USA
| | - Biju Issac
- Biostatistics and Bioinformatics Core/Division of Bioinformatics, Clinical Research Building, University of Miami/Sylvester Comprehensive Cancer Center, 1120 NW 14th Street, 6th Floor, Room 610L, Miami, FL, 33136, USA
| | - Micheline McCarthy
- Bruce W. Carter Veterans Affairs Medical Center, 1201 NW 16th Street, Miami, FL, 33125, USA. .,Department of Neurology, Miller School of Medicine, University of Miami, 1120 NW 14th St, Miami, FL, 33136, USA.
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Magistri M, Khoury N, Mazza EMC, Velmeshev D, Lee JK, Bicciato S, Tsoulfas P, Faghihi MA. A comparative transcriptomic analysis of astrocytes differentiation from human neural progenitor cells. Eur J Neurosci 2016; 44:2858-2870. [PMID: 27564458 DOI: 10.1111/ejn.13382] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/25/2016] [Accepted: 08/23/2016] [Indexed: 12/11/2022]
Abstract
Astrocytes are a morphologically and functionally heterogeneous population of cells that play critical roles in neurodevelopment and in the regulation of central nervous system homeostasis. Studies of human astrocytes have been hampered by the lack of specific molecular markers and by the difficulties associated with purifying and culturing astrocytes from adult human brains. Human neural progenitor cells (NPCs) with self-renewal and multipotent properties represent an appealing model system to gain insight into the developmental genetics and function of human astrocytes, but a comprehensive molecular characterization that confirms the validity of this cellular system is still missing. Here we used an unbiased transcriptomic analysis to characterize in vitro culture of human NPCs and to define the gene expression programs activated during the differentiation of these cells into astrocytes using FBS or the combination of CNTF and BMP4. Our results demonstrate that in vitro cultures of human NPCs isolated during the gliogenic phase of neurodevelopment mainly consist of radial glial cells (RGCs) and glia-restricted progenitor cells. In these cells the combination of CNTF and BMP4 activates the JAK/STAT and SMAD signaling cascades, leading to the inhibition of oligodendrocytes lineage commitment and activation of astrocytes differentiation. On the other hand, FBS-derived astrocytes have properties of reactive astrocytes. Our work suggests that in vitro culture of human NPCs represents a valuable cellular system to study human disorders characterized by impairment of astrocytes development and function. Our datasets represent an important resource for researchers studying human astrocytes development and might set the basis for the discovery of novel human-specific astrocyte markers.
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Affiliation(s)
- Marco Magistri
- Department of Psychiatry and Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, BRB 508, Miami, FL, 33136, USA
| | - Nathalie Khoury
- Department of Psychiatry and Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, BRB 508, Miami, FL, 33136, USA
| | - Emilia Maria Cristina Mazza
- Department of Life Sciences, Center for Genome Research, University of Modena and Reggio Emilia, Modena, Italy
| | - Dmitry Velmeshev
- Department of Psychiatry and Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, BRB 508, Miami, FL, 33136, USA
| | - Jae K Lee
- Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Silvio Bicciato
- Department of Life Sciences, Center for Genome Research, University of Modena and Reggio Emilia, Modena, Italy
| | - Pantelis Tsoulfas
- Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Mohammad Ali Faghihi
- Department of Psychiatry and Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, BRB 508, Miami, FL, 33136, USA
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Magistri M, Velmeshev D, Makhmutova M, Faghihi MA. Transcriptomics Profiling of Alzheimer's Disease Reveal Neurovascular Defects, Altered Amyloid-β Homeostasis, and Deregulated Expression of Long Noncoding RNAs. J Alzheimers Dis 2016; 48:647-65. [PMID: 26402107 PMCID: PMC4698155 DOI: 10.3233/jad-150398] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The underlying genetic variations of late-onset Alzheimer's disease (LOAD) cases remain largely unknown. A combination of genetic variations with variable penetrance and lifetime epigenetic factors may converge on transcriptomic alterations that drive LOAD pathological process. Transcriptome profiling using deep sequencing technology offers insight into common altered pathways regardless of underpinning genetic or epigenetic factors and thus represents an ideal tool to investigate molecular mechanisms related to the pathophysiology of LOAD. We performed directional RNA sequencing on high quality RNA samples extracted from hippocampi of LOAD and age-matched controls. We further validated our data using qRT-PCR on a larger set of postmortem brain tissues, confirming downregulation of the gene encoding substance P (TAC1) and upregulation of the gene encoding the plasminogen activator inhibitor-1 (SERPINE1). Pathway analysis indicates dysregulation in neural communication, cerebral vasculature, and amyloid-β clearance. Beside protein coding genes, we identified several annotated and non-annotated long noncoding RNAs that are differentially expressed in LOAD brain tissues, three of them are activity-dependent regulated and one is induced by Aβ(1-42) exposure of human neural cells. Our data provide a comprehensive list of transcriptomics alterations in LOAD hippocampi and warrant holistic approach including both coding and non-coding RNAs in functional studies aimed to understand the pathophysiology of LOAD.
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Affiliation(s)
| | | | | | - Mohammad Ali Faghihi
- Correspondence to: Dr. Mohammad A. Faghihi, Center for Therapeutic Innovation & Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Ave, BRB 508, Miami, FL 33136, USA.
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Fantetti KN, Gray EL, Ganesan P, Kulkarni A, O'Donnell LA. Interferon gamma protects neonatal neural stem/progenitor cells during measles virus infection of the brain. J Neuroinflammation 2016; 13:107. [PMID: 27178303 PMCID: PMC4867982 DOI: 10.1186/s12974-016-0571-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 05/06/2016] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND In the developing brain, self-renewing neural stem/progenitor cells (NSPC) give rise to neuronal and glial lineages. NSPC survival and differentiation can be altered by neurotropic viruses and by the anti-viral immune response. Several neurotropic viruses specifically target and infect NSPCs, in addition to inducing neuronal loss, which makes it difficult to distinguish between effects on NSPCs that are due to direct viral infection or due to the anti-viral immune response. METHODS We have investigated the impact of anti-viral immunity on NSPCs in measles virus (MV)-infected neonates. A neuron-restricted viral infection model was used, where NSPCs remain uninfected. Thus, an anti-viral immune response was induced without the confounding issue of NSPC infection. Two-transgenic mouse lines were used: CD46+ mice express the human isoform of CD46, the MV entry receptor, under the control of the neuron-specific enolase promoter; CD46+/IFNγ-KO mice lack the key anti-viral cytokine IFNγ. Multi-color flow cytometry and Western Blot analysis were used to quantify effects on NSPC, neuronal, and glial cell number, and quantify effects on IFNγ-mediated signaling and cell markers, respectively. RESULTS Flow cytometric analysis revealed that NSPCs were reduced in CD46+/IFNγ-KO mice at 3, 7, and 10 days post-infection (dpi), but were unaffected in CD46+ mice. Early neurons showed the greatest cell loss at 7 dpi in both genotypes, with no effect on mature neurons and glial cells. Thus, IFNγ protected against NSPC loss, but did not protect young neurons. Western Blot analyses on hippocampal explants showed reduced nestin expression in the absence of IFNγ, and reduced doublecortin and βIII-tubulin in both genotypes. Phosphorylation of STAT1 and STAT2 occurred independently of IFNγ in the hippocampus, albeit with distinct regulation of activation. CONCLUSIONS This is the first study to demonstrate bystander effects of anti-viral immunity on NSPC function. Our results show IFNγ protects the NSPC population during a neonatal viral CNS infection. Significant loss of NSPCs in CD46+/IFNγ-KO neonates suggests that the adaptive immune response is detrimental to NSPCs in the absence of IFNγ. These results reveal the importance and contribution of the anti-viral immune response to neuropathology and may be relevant to other neuroinflammatory conditions.
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Affiliation(s)
- Kristen N Fantetti
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA
| | - Erica L Gray
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA
| | - Priya Ganesan
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA
| | - Apurva Kulkarni
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA
| | - Lauren A O'Donnell
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA.
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Abstract
Human immunodeficiency virus (HIV) invades the brain early during infection and generates a chronic inflammatory microenvironment that can eventually result in neurological disease, even in the absence of significant viral replication. Thus, HIV-1 infection of the brain has been characterized both as a neuroimmunological and neurodegenerative disorder. While the brain and central nervous system (CNS) have historically been regarded as immune privileged or immunologically quiescent, newer concepts of CNS immunity suggest an important if not defining role for innate immune responses generated by glial cells. Innate immunity may be the first line of defense against HIV infection of the brain and CNS, with multiple cellular elements providing responses that can be anti-viral and neuroprotective, but also potentially neurotoxic, impairing neurogenesis and promoting neuronal apoptosis. To investigate the effects of HIV exposure on neurogenesis and neuronal survival, we have studied the responses of human neuroepithelial progenitor (NEP) cells, which undergo directed differentiation into astrocytes and neurons in vitro. We identified a group of genes that were differentially expressed in NEP-derived cells during virus exposure. This included genes that are strongly related to interferon-induced responses and antigen presentation. Moreover, we observed that the host factor apolipoprotein E influences the innate immune response expressed by these cells, with a more robust response in the apolipoprotein E3/E3 genotype cultures compared to the apolipoprotein E3/E4 counterparts. Thus, neuroepithelial progenitors and their differentiated progeny recognize HIV and respond to it by mounting an innate immune response with a vigor that is influenced by the host factor apolipoprotein E.
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Depressed neurofilament expression associates with apolipoprotein E3/E4 genotype in maturing human fetal neurons exposed to HIV-1. J Neurovirol 2013; 18:323-30. [PMID: 22302611 DOI: 10.1007/s13365-012-0079-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 01/05/2012] [Accepted: 01/09/2012] [Indexed: 10/14/2022]
Abstract
Exposure of differentiating human neural progenitor cells (NEP) to HIV-1 results in a neuronal“failure to thrive” phenotype characterized by a relative decrease in neurofilament-light (NF-L) expression. However,when NEP were segregated by their apolipoproteinE genotype, differentiating apolipoprotein E3/E4 cells showed reduced NF-L expression upon HIV-1 exposure,but differentiating apolipoprotein E3/E3 or apolipoproteinE4/E4 cells did not. These data suggest that apolipoproteinE genotype is a host factor that could affect the development of neurocognitive dysfunction in HIV-1 infected individuals.
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Geffin R, Martinez R, Perez R, Issac B, McCarthy M. Apolipoprotein E-dependent differences in innate immune responses of maturing human neuroepithelial progenitor cells exposed to HIV-1. J Neuroimmune Pharmacol 2013; 8:1010-26. [PMID: 23744346 DOI: 10.1007/s11481-013-9478-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 05/21/2013] [Indexed: 01/14/2023]
Abstract
HIV enters the brain early during infection and induces a chronic inflammatory state that can result in neurological abnormalities in a subset of infected individuals. To investigate the effects of HIV exposure on neurogenesis and neuronal survival in the brain, we have used a model system consisting of human neuroepithelial progenitor (NEP) cells that undergo directed differentiation into astrocytes and neurons in vitro. Changes in gene expression in NEP cultures as a result of HIV exposure were investigated using gene expression microarrays with the Illumina HT-12 V4_0_R1 platform array. Through this approach, we identified a group of genes specifically upregulated by exposure to virus that are strongly related to interferon induced responses and antigen presentation. When the data were stratified by their apolipoprotein genotype, this innate immune response was more robust in the apolipoprotein E3/E3 genotype cultures than in the apolipoprotein E3/E4 counterparts. Biological processes as defined by the gene ontology (GO) program were also differently affected upon virus exposure in cultures of the two genotypes, particularly those related to antigen presentation and the actions of interferons. Differences occurred in both in numbers of genes affected and their significance in the GO processes in which they participate, with apoE3/E3 > apoE3/E4. These data suggest that maturing NEP cultures recognize HIV and respond to it by mounting an innate immune response with a vigor that is influenced by the apolipoprotein E genotype of the cells.
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Affiliation(s)
- Rebeca Geffin
- Research Service, Bruce W. Carter Veterans Affairs Medical Center, 1201 NW 16th Street, Miami, FL 33125, USA
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10
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Rao JS, Kim HW, Harry GJ, Rapoport SI, Reese EA. RETRACTED: Increased neuroinflammatory and arachidonic acid cascade markers, and reduced synaptic proteins, in the postmortem frontal cortex from schizophrenia patients. Schizophr Res 2013; 147:24-31. [PMID: 23566496 PMCID: PMC3812915 DOI: 10.1016/j.schres.2013.02.017] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 02/12/2013] [Accepted: 02/19/2013] [Indexed: 12/22/2022]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editors. The National Institutes of Health has found that Dr. Jagadeesh S. Rao engaged in research misconduct by falsifying data. Data in Figures 1A, 1E, 3E and 3F were falsified. Dr. Rao was solely responsible for the falsification. None of the other authors are implicated in any way.
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Affiliation(s)
- Jagadeesh Sridhara Rao
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA.
| | - Hyung-Wook Kim
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - Gaylia Jean Harry
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Stanley Isaac Rapoport
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - Edmund Arthur Reese
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
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Borna disease virus infects human neural progenitor cells and impairs neurogenesis. J Virol 2011; 86:2512-22. [PMID: 22190725 DOI: 10.1128/jvi.05663-11] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Understanding the complex mechanisms by which infectious agents can disrupt behavior represents a major challenge. The Borna disease virus (BDV), a potential human pathogen, provides a unique model to study such mechanisms. Because BDV induces neurodegeneration in brain areas that are still undergoing maturation at the time of infection, we tested the hypothesis that BDV interferes with neurogenesis. We showed that human neural stem/progenitor cells are highly permissive to BDV, although infection does not alter their survival or undifferentiated phenotype. In contrast, upon the induction of differentiation, BDV is capable of severely impairing neurogenesis by interfering with the survival of newly generated neurons. Such impairment was specific to neurogenesis, since astrogliogenesis was unaltered. In conclusion, we demonstrate a new mechanism by which BDV might impair neural function and brain plasticity in infected individuals. These results may contribute to a better understanding of behavioral disorders associated with BDV infection.
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Rao JS, Kim HW, Kellom M, Greenstein D, Chen M, Kraft AD, Harry GJ, Rapoport SI, Basselin M. Increased neuroinflammatory and arachidonic acid cascade markers, and reduced synaptic proteins, in brain of HIV-1 transgenic rats. J Neuroinflammation 2011; 8:101. [PMID: 21846384 PMCID: PMC3175175 DOI: 10.1186/1742-2094-8-101] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 08/16/2011] [Indexed: 12/23/2022] Open
Abstract
Background Cognitive impairment has been reported in human immune deficiency virus-1- (HIV-1-) infected patients as well as in HIV-1 transgenic (Tg) rats. This impairment has been linked to neuroinflammation, disturbed brain arachidonic acid (AA) metabolism, and synapto-dendritic injury. We recently reported upregulated brain AA metabolism in 7- to 9-month-old HIV-1 Tg rats. We hypothesized that these HIV-1 Tg rats also would show upregulated brain inflammatory and AA cascade markers and a deficit of synaptic proteins. Methods We measured protein and mRNA levels of markers of neuroinflammation and the AA cascade, as well as pro-apoptotic factors and synaptic proteins, in brains from 7- to 9-month-old HIV-1 Tg and control rats. Results Compared with control brain, HIV-1 Tg rat brain showed immunoreactivity to glycoprotein 120 and tat HIV-1 viral proteins, and significantly higher protein and mRNA levels of (1) the inflammatory cytokines interleukin-1β and tumor necrosis factor α, (2) the activated microglial/macrophage marker CD11b, (3) AA cascade enzymes: AA-selective Ca2+-dependent cytosolic phospholipase A2 (cPLA2)-IVA, secretory sPLA2-IIA, cyclooxygenase (COX)-2, membrane prostaglandin E2 synthase, 5-lipoxygenase (LOX) and 15-LOX, cytochrome p450 epoxygenase, and (4) transcription factor NF-κBp50 DNA binding activity. HIV-1 Tg rat brain also exhibited signs of cell injury, including significantly decreased levels of brain-derived neurotrophic factor (BDNF) and drebrin, a marker of post-synaptic excitatory dendritic spines. Expression of Ca2+-independent iPLA2-VIA and COX-1 was unchanged. Conclusions HIV-1 Tg rats show elevated brain markers of neuroinflammation and AA metabolism, with a deficit in several synaptic proteins. These changes are associated with viral proteins and may contribute to cognitive impairment. The HIV-1 Tg rat may be a useful model for understanding progression and treatment of cognitive impairment in HIV-1 patients.
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Affiliation(s)
- Jagadeesh Sridhara Rao
- Brain Physiology and Metabolism Section, National Institute on Aging, Bethesda, MD 20892, USA.
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Martinez R, Eraso D, Geffin R, McCarthy M. A two-culture method for exposure of human brain organotypic slice cultures to replicating human immunodeficiency virus type 1. J Neurosci Methods 2011; 200:74-9. [DOI: 10.1016/j.jneumeth.2011.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 06/16/2011] [Accepted: 06/18/2011] [Indexed: 11/28/2022]
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Abstract
Neuronal damage induced by ongoing human immunodeficiency virus type 1 (HIV-1) infection was investigated in humanized NOD/scid-IL-2Rγ(c)(null) mice transplanted at birth with human CD34-positive hematopoietic stem cells. Mice infected at 5 months of age and followed for up to 15 weeks maintained significant plasma viral loads and showed reduced numbers of CD4(+) T-cells. Prospective serial proton magnetic resonance spectroscopy tests showed selective reductions in cortical N-acetyl aspartate in infected animals. Diffusion tensor imaging revealed structural changes in cortical gray matter. Postmortem immunofluorescence brain tissue examinations for neuronal and glial markers, captured by multispectral imaging microscopy and quantified by morphometric and fluorescence emission, showed regional reduction of neuronal soma and synaptic architectures. This was evidenced by loss of microtubule-associated protein 2, synaptophysin, and neurofilament antigens. This study is the first, to our knowledge, demonstrating lost neuronal integrity after HIV-1 infection in humanized mice. As such, the model permits studies of the relationships between ongoing viral replication and virus-associated neurodegeneration.
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Mishra M, Taneja M, Malik S, Khalique H, Seth P. Human immunodeficiency virus type 1 Tat modulates proliferation and differentiation of human neural precursor cells: implication in NeuroAIDS. J Neurovirol 2011; 16:355-67. [PMID: 20839920 DOI: 10.3109/13550284.2010.513028] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) and viral proteins affect neuronal survival and neuron-glial cell interactions, which culminate in neurological disorders. HIV-1 infects regions of neurogenesis in human adult and pediatric brain. However, little is known about the effect of HIV-1 or viral proteins on the properties of human neural precursor cells (hNPCs), particularly neurogenesis, hence a detailed investigation on these lines is warranted. Human neural precursor cells were cultured in presence and absence of HIV-1B transactivating protein Tat to investigate if HIV-1 viral protein alters the properties of human neural precursor cells. Cellular and molecular approaches were adopted to study the effect of HIV-1B transactivating protein Tat on proliferation and differentiation potential of human fetal brain-derived NPCs. Cell proliferation assays such as BrdU and Ki67 staining and pathway-specific cDNA and protein arrays were used in the study. Data reveal that HIV-1B Tat protein severely affects proliferation of hNPCs, as evident by lower incorporation of BrdU and Ki67 staining as well as neurosphere assay. HIV-1 Tat substantially attenuated neurogenesis, as evident by the smaller numbers of Tuj-1- and doublecortin-positive cells differentiated from hNPCs, without affecting their viability. These data suggest that HIV-1 Tat alters the properties of human neural precursor cells via attenuation of the cell cycle regulatory unit cyclin D1 and the mitogen-activated protein kinase (MAPK) pathway, particularly extracellular signal-related kinase 1/2 (ERK1/2). The study provides new insights into cellular and molecular mechanisms that may modulate human neural precursor cell properties in HIV/AIDS (acquired immunodeficiency syndrome) individuals. Validation with autopsy brain samples is necessary to further substantiate these important observations.
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Affiliation(s)
- Mamata Mishra
- Molecular and Cellular Neuroscience, National Brain Research Center, Manesar, Haryana, India
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