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Faia C, Plaisance-Bonstaff K, Peruzzi F. In vitro models of HIV-1 infection of the Central Nervous System. DRUG DISCOVERY TODAY. DISEASE MODELS 2020; 32:5-11. [PMID: 33692833 PMCID: PMC7938360 DOI: 10.1016/j.ddmod.2019.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Neurocognitive disorders associated with HIV-1 infection affect more than half of persons living with HIV (PLWH) under retroviral therapy. Understanding the molecular mechanisms and the complex cellular network communication underlying neurological dysfunction is critical for the development of an effective therapy. As with other neurological disorders, challenges to studying HIV infection of the brain include limited access to clinical samples and proper reproducibility of the complexity of brain networks in cellular and animal models. This review focuses on cellular models used to investigate various aspects of neurological dysfunction associated with HIV infection.
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Affiliation(s)
- Celeste Faia
- Louisiana State University Health Sciences Center and S Stanley Scott Cancer Center
- Department of Microbiology Immunology and Parasitology
| | | | - Francesca Peruzzi
- Louisiana State University Health Sciences Center and S Stanley Scott Cancer Center
- Department of Microbiology Immunology and Parasitology
- Department of Medicine
- Corresponding author: Francesca Peruzzi, 1700 Tulane Ave, New Orleans, LA 70112, Tel: (504) 210-2978,
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2
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HIV-1 Tat inhibits EAAT-2 through AEG-1 upregulation in models of HIV-associated neurocognitive disorder. Oncotarget 2018; 8:39922-39934. [PMID: 28404980 PMCID: PMC5503662 DOI: 10.18632/oncotarget.16485] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 01/23/2017] [Indexed: 11/25/2022] Open
Abstract
During HIV-associated neurocognitive disorder (HAND), decreasing in excitatory amino acid transporter 2 (EAAT-2) in astrocyte plasma membranes leads to elevated levels of extracellular glutamate and, in turn, neuronal apoptosis. We used immunohistochemistry, western blot, qRT-PCR, and RNA interference to elucidate the molecular mechanisms underlying the decreased EAAT-2 expression during HAND at the tissue and cellular levels. We used simian immunodeficiency virus-human immunodeficiency virus chimeric virus (SHIV)-infected macaques as an in vivo model of HAND. Our results show that EAAT-2 expression was decreased in the cerebral cortex, while AEG-1 expression was increased, and the expression levels of these proteins were negatively correlated. In vitro analyses showed that HIV-1 Tat inhibited EAAT-2 expression by inducing overexpression of AEG-1. More specifically, HIV-1 Tat increased AEG-1 expression via the PI3-K signaling pathway, while increasing EAAT-2 inhibition by YinYan-1 (YY-1) via the NF-κB signaling pathway. These results warrant testing AEG-1 as a potential therapeutic target for treating HAND.
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Chen NC, Partridge AT, Sell C, Torres C, Martín-García J. Fate of microglia during HIV-1 infection: From activation to senescence? Glia 2016; 65:431-446. [PMID: 27888531 DOI: 10.1002/glia.23081] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/12/2016] [Accepted: 09/20/2016] [Indexed: 12/14/2022]
Abstract
Microglia support productive human immunodeficiency virus type 1 (HIV-1) infection and disturbed microglial function could contribute to the development of HIV-associated neurocognitive disorders (HAND). Better understanding of how HIV-1 infection and viral protein exposure modulate microglial function during the course of infection could lead to the identification of novel therapeutic targets for both the eradication of HIV-1 reservoir and treatment of neurocognitive deficits. This review first describes microglial origins and function in the normal central nervous system (CNS), and the changes that occur during aging. We then critically discuss how HIV-1 infection and exposure to viral proteins such as Tat and gp120 affect various aspects of microglial homeostasis including activation, cellular metabolism and cell cycle regulation, through pathways implicated in cellular stress responses including p38 mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB). We thus propose that the functions of human microglia evolve during both healthy and pathological aging. Aging-associated dysfunction of microglia comprises phenotypes resembling cellular senescence, which could contribute to cognitive impairments observed in various neurodegenerative diseases. In addition, microglia seems to develop characteristics that could be related to cellular senescence post-HIV-1 infection and after exposure to HIV-1 viral proteins. However, despite its potential role as a component of HAND and likely other neurocognitive disorders, microglia senescence has not been well characterized and should be the focus of future studies, which could have high translational relevance. GLIA 2017;65:431-446.
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Affiliation(s)
- Natalie C Chen
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania.,MD/PhD Program, Drexel University College of Medicine, Philadelphia, Pennsylvania.,Molecular and Cell Biology and Genetics Graduate Program, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Andrea T Partridge
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania.,Microbiology and Immunology Graduate Program, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Christian Sell
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Claudio Torres
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Julio Martín-García
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania.,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania
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4
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Zilbermintz L, Leonardi W, Tran SH, Zozaya J, Mathew-Joseph A, Liem S, Levitin A, Martchenko M. Cross-inhibition of pathogenic agents and the host proteins they exploit. Sci Rep 2016; 6:34846. [PMID: 27703274 PMCID: PMC5050486 DOI: 10.1038/srep34846] [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: 06/21/2016] [Accepted: 09/19/2016] [Indexed: 11/09/2022] Open
Abstract
The major limitations of pathogen-directed therapies are the emergence of drug-resistance and their narrow spectrum of coverage. A recently applied approach directs therapies against host proteins exploited by pathogens in order to circumvent these limitations. However, host-oriented drugs leave the pathogens unaffected and may result in continued pathogen dissemination. In this study we aimed to discover drugs that could simultaneously cross-inhibit pathogenic agents, as well as the host proteins that mediate their lethality. We observed that many pathogenic and host-assisting proteins belong to the same functional class. In doing so we targeted a protease component of anthrax toxin as well as host proteases exploited by this toxin. We identified two approved drugs, ascorbic acid 6-palmitate and salmon sperm protamine, that effectively inhibited anthrax cytotoxic protease and demonstrated that they also block proteolytic activities of host furin, cathepsin B, and caspases that mediate toxin's lethality in cells. We demonstrated that these drugs are broad-spectrum and reduce cellular sensitivity to other bacterial toxins that require the same host proteases. This approach should be generally applicable to the discovery of simultaneous pathogen and host-targeting inhibitors of many additional pathogenic agents.
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Affiliation(s)
| | | | | | - Josue Zozaya
- Keck Graduate Institute, Claremont, CA 91711, USA
| | | | - Spencer Liem
- Keck Graduate Institute, Claremont, CA 91711, USA
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Zhao X, Qian L, Zhou D, Qi D, Liu C, Kong X. Stability of HIV-1 subtype B and C Tat is associated with variation in the carboxyl-terminal region. Virol Sin 2016; 31:199-206. [PMID: 27007880 DOI: 10.1007/s12250-016-3681-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 03/01/2016] [Indexed: 12/14/2022] Open
Abstract
The multifunctional trans-activator Tat is an essential regulatory protein for HIV-1 replication and is characterized by high sequence diversity. Numerous experimental studies have examined Tat in HIV-1 subtype B, but research on subtype C Tat is lacking, despite the high prevalence of infections caused by subtype C worldwide. We hypothesized that amino acid differences contribute to functional differences among Tat proteins. In the present study, we found that subtype B NL4-3 Tat and subtype C isolate HIV1084i Tat exhibited differences in stability by overexpressing the fusion protein Tat-Flag. In addition, 1084i Tat can activate LTR and NF-κB more efficiently than NL4-3 Tat. In analyses of the activities of the truncated forms of Tat, we found that the carboxyl-terminal region of Tat regulates its stability and transactivity. According to our results, we speculated that the differences in stability between B-Tat and C-Tat result in differences in transactivation ability.
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Affiliation(s)
- Xuechao Zhao
- Laboratory of Medical Molecular Virology, School of Medicine, Nankai University, Tianjin, 300071, China
| | - Lingyu Qian
- Laboratory of Medical Molecular Virology, School of Medicine, Nankai University, Tianjin, 300071, China
| | - Deyu Zhou
- Laboratory of Medical Molecular Virology, School of Medicine, Nankai University, Tianjin, 300071, China
| | - Di Qi
- Laboratory of Medical Molecular Virology, School of Medicine, Nankai University, Tianjin, 300071, China
| | - Chang Liu
- Laboratory of Medical Molecular Virology, School of Medicine, Nankai University, Tianjin, 300071, China
| | - Xiaohong Kong
- Laboratory of Medical Molecular Virology, School of Medicine, Nankai University, Tianjin, 300071, China.
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Kadri F, Pacifici M, Wilk A, Parker-Struckhoff A, Del Valle L, Hauser KF, Knapp PE, Parsons C, Jeansonne D, Lassak A, Peruzzi F. HIV-1-Tat Protein Inhibits SC35-mediated Tau Exon 10 Inclusion through Up-regulation of DYRK1A Kinase. J Biol Chem 2015; 290:30931-46. [PMID: 26534959 PMCID: PMC4692221 DOI: 10.1074/jbc.m115.675751] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 11/02/2015] [Indexed: 01/08/2023] Open
Abstract
The HIV-1 transactivator protein Tat is implicated in the neuronal damage that contributes to neurocognitive impairment affecting people living with HIV/AIDS. Aberrant splicing of TAU exon 10 results in tauopathies characterized by alterations in the proportion of TAU isoforms containing three (3R) or four (4R) microtubule-binding repeats. The splicing factor SC35/SRSF2 binds to nuclear RNA and facilitates the incorporation of exon 10 in the TAU molecule. Here, we utilized clinical samples, an animal model, and neuronal cell cultures and found that Tat promotes TAU 3R up-regulation through increased levels of phosphorylated SC35, which is retained in nuclear speckles. This mechanism involved Tat-mediated increased expression of DYRK1A and was prevented by DYRK1A silencing. In addition, we found that Tat associates with TAU RNA, further demonstrating that Tat interferes with host RNA metabolism in the absence of viral infection. Altogether, our data unravel a novel mechanism of Tat-mediated neuronal toxicity through dysregulation of the SC35-dependent alternative splicing of TAU exon 10. Furthermore, the increased immunostaining of DYRK1A in HIV+ brains without pathology points at dysregulation of DYRK1A as an early event in the neuronal complications of HIV infection.
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Affiliation(s)
- Ferdous Kadri
- From the Department of Medicine, Stanley S. Scott Cancer Center, and Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112 and
| | - Marco Pacifici
- From the Department of Medicine, Stanley S. Scott Cancer Center, and
| | - Anna Wilk
- From the Department of Medicine, Stanley S. Scott Cancer Center, and
| | | | - Luis Del Valle
- From the Department of Medicine, Stanley S. Scott Cancer Center, and
| | | | - Pamela E Knapp
- Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia 23284
| | | | - Duane Jeansonne
- From the Department of Medicine, Stanley S. Scott Cancer Center, and
| | - Adam Lassak
- From the Department of Medicine, Stanley S. Scott Cancer Center, and
| | - Francesca Peruzzi
- From the Department of Medicine, Stanley S. Scott Cancer Center, and
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Zhang L, Qin J, Li Y, Wang J, He Q, Zhou J, Liu M, Li D. Modulation of the stability and activities of HIV-1 Tat by its ubiquitination and carboxyl-terminal region. Cell Biosci 2014; 4:61. [PMID: 25328666 PMCID: PMC4201738 DOI: 10.1186/2045-3701-4-61] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 09/27/2014] [Indexed: 11/28/2022] Open
Abstract
Background The transactivator of transcription (Tat) protein of human immunodeficiency virus type 1 (HIV-1) is known to undergo ubiquitination. However, the roles of ubiquitination in regulating Tat stability and activities are unclear. In addition, although the 72- and 86-residue forms are commonly used for in vitro studies, the 101-residue form is predominant in the clinical isolates of HIV-1. The influence of the carboxyl-terminal region of Tat on its functions remains unclear. Results In this study, we find that Tat undergoes lysine 48-linked ubiquitination and is targeted to proteasome-dependent degradation. Expression of various ubiquitin mutants modulates Tat activities, including the transactivation of transcription, induction of apoptosis, interaction with tubulin, and stabilization of microtubules. Moreover, the 72-, 86- and 101-residue forms of Tat also exhibit different stability and aforementioned activities. Conclusions Our findings demonstrate that the ubiquitination and carboxyl-terminal region of Tat are critical determinants of its stability and activities.
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Affiliation(s)
- Linlin Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Juan Qin
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Yuanyuan Li
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Jian Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Qianqian He
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Jun Zhou
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Min Liu
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Dengwen Li
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, 300071 China
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Krogh KA, Wydeven N, Wickman K, Thayer SA. HIV-1 protein Tat produces biphasic changes in NMDA-evoked increases in intracellular Ca2+ concentration via activation of Src kinase and nitric oxide signaling pathways. J Neurochem 2014; 130:642-56. [PMID: 24666322 DOI: 10.1111/jnc.12724] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 03/05/2014] [Accepted: 03/11/2014] [Indexed: 11/30/2022]
Abstract
HIV-associated neurocognitive disorders afflict about half of HIV-infected patients. HIV-infected cells shed viral proteins, such as the transactivator of transcription (Tat), which can cause neurotoxicity by over activation of NMDA receptors. Here, we show that Tat causes a time-dependent, biphasic change in NMDA-evoked increases in intracellular Ca(2+) concentration ([Ca(2+)]i). NMDA-evoked responses were potentiated following 2-h exposure to Tat (50 ng/mL). Tat-induced potentiation of NMDA-evoked increases in [Ca(2+)]i peaked by 8 h and then adapted by gradually reversing to baseline by 24 h and eventually dropping below control by 48 h. Tat-induced potentiation of NMDA-evoked responses was blocked by inhibition of lipoprotein receptor-related protein (LRP) or Src tyrosine kinase. Potentiation was unaffected by inhibition of nitric oxide synthase (NOS). However, NOS activity was required for adaptation. Adaptation was also prevented by inhibition of soluble guanylate cyclase (sGC) and cyclic guanosine monophosphate-dependent protein kinase G (PKG). Together, these findings indicate that Tat potentiates NMDA-evoked increases in [Ca(2+)]i via LRP-dependent activation of Src and that this potentiation adapts via activation of the NOS/sGC/PKG pathway. Adaptation may protect neurons from excessive Ca(2+) influx and could reveal targets for the treatment of HIV-associated neurocognitive disorders. HIV-associated neurocognitive disorders (HAND) afflict about half of HIV-infected patients. HIV-infected cells shed viral proteins, such as the transactivator of transcription (Tat), which can cause neurotoxicity by over activation of NMDA receptors (NMDARs). We show that HIV-1 Tat evoked biphasic changes in NMDA-evoked [Ca(2+) ]i responses. Initially, Tat potentiated NMDA-evoked responses following LRP-mediated activation of Src kinase. Subsequently, Tat-induced NMDAR potentiation adapted by activation of a NOS/sGC/PKG pathway that attenuated NMDA-evoked increases in [Ca(2+)]i . Adaptation may be a novel neuroprotective mechanism to prevent excessive Ca(2+) influx. Solid and dashed arrows represent direct and potentially indirect connections, respectively.
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Affiliation(s)
- Kelly A Krogh
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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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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Donkor IO. Calpain inhibitors: a survey of compounds reported in the patent and scientific literature. Expert Opin Ther Pat 2011; 21:601-36. [DOI: 10.1517/13543776.2011.568480] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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