1
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Cui BC, Aksenova M, Sikirzhytskaya A, Odhiambo D, Korunova E, Sikirzhytski V, Ji H, Altomare D, Broude E, Frizzell N, Booze R, Wyatt MD, Shtutman M. Suppression of HIV-TAT and cocaine-induced neurotoxicity and inflammation by cell penetrable itaconate esters. J Neurovirol 2024:10.1007/s13365-024-01216-9. [PMID: 38884890 DOI: 10.1007/s13365-024-01216-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 04/20/2024] [Accepted: 05/20/2024] [Indexed: 06/18/2024]
Abstract
HIV-associated neurological disorder (HAND) is a serious complication of HIV infection marked by neurotoxicity induced by viral proteins like Tat. Substance abuse exacerbates neurocognitive impairment in people living with HIV. There is an urgent need for therapeutic strategies to combat HAND comorbid with Cocaine Use Disorder (CUD). Our analysis of HIV and cocaine-induced transcriptomes in primary cortical cultures revealed significant overexpression of the macrophage-specific gene aconitate decarboxylase 1 (Acod1). The ACOD1 protein converts the tricarboxylic acid intermediate cis-aconitate into itaconate during the activation of inflammation. Itaconate then facilitates cytokine production and activates anti-inflammatory transcription factors, shielding macrophages from infection-induced cell death. However, the immunometabolic function of itaconate was unexplored in HIV and cocaine-exposed microglia. We assessed the potential of 4-octyl-itaconate (4OI), a cell-penetrable ester form of itaconate known for its anti-inflammatory properties. When primary cortical cultures exposed to Tat and cocaine were treated with 4OI, microglial cell number increased and the morphological altercations induced by Tat and cocaine were reversed. Microglial cells also appeared more ramified, resembling the quiescent microglia. 4OI treatment inhibited secretion of the proinflammatory cytokines IL-1α, IL-1β, IL-6, and MIP1-α induced by Tat and cocaine. Transcriptome profiling determined that Nrf2 target genes were significantly activated in Tat and 4OI treated cultures relative to Tat alone. Further, genes associated with cytoskeleton dynamics in inflammatory microglia were downregulated by 4OI treatment. Together, the results strongly suggest 4-octyl-itaconate holds promise as a potential candidate for therapeutic development to treat HAND coupled with CUD comorbidities.
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Affiliation(s)
- B Celia Cui
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Marina Aksenova
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Aliaksandra Sikirzhytskaya
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Diana Odhiambo
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Elizaveta Korunova
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Vitali Sikirzhytski
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Hao Ji
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Diego Altomare
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Eugenia Broude
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Norma Frizzell
- Department of Pharmacology, Physiology and Neuroscience, School of Medicine, University of South Carolina, Columbia, SC, 29208, USA
| | - Rosemarie Booze
- Department of Psychology, College of Arts and Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | - Michael D Wyatt
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Michael Shtutman
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA.
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2
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Shang L, Wei H, Deng J, Stewart MJ, LeSaint JE, Kyomuhangi A, Park S, Maul EC, Zhan CG, Zheng F. In vitro and in vivo stability of a highly efficient long-acting cocaine hydrolase. Sci Rep 2024; 14:10952. [PMID: 38740850 PMCID: PMC11091111 DOI: 10.1038/s41598-024-61646-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 05/08/2024] [Indexed: 05/16/2024] Open
Abstract
It is recognized as a promising therapeutic strategy for cocaine use disorder to develop an efficient enzyme which can rapidly convert cocaine to physiologically inactive metabolites. We have designed and discovered a series of highly efficient cocaine hydrolases, including CocH5-Fc(M6) which is the currently known as the most efficient cocaine hydrolase with both the highest catalytic activity against (-)-cocaine and the longest biological half-life in rats. In the present study, we characterized the time courses of protein appearance, pH, structural integrity, and catalytic activity against cocaine in vitro and in vivo of a CocH5-Fc(M6) bulk drug substance produced in a bioreactor for its in vitro and in vivo stability after long-time storage under various temperatures (- 80, - 20, 4, 25, or 37 °C). Specifically, all the tested properties of the CocH5-Fc(M6) protein did not significantly change after the protein was stored at any of four temperatures including - 80, - 20, 4, and 25 °C for ~ 18 months. In comparison, at 37 °C, the protein was less stable, with a half-life of ~ 82 days for cocaine hydrolysis activity. Additionally, the in vivo studies further confirmed the linear elimination PK profile of CocH5-Fc(M6) with an elimination half-life of ~ 9 days. All the in vitro and in vivo data on the efficacy and stability of CocH5-Fc(M6) have consistently demonstrated that CocH5-Fc(M6) has the desired in vitro and in vivo stability as a promising therapeutic candidate for treatment of cocaine use disorder.
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Affiliation(s)
- Linyue Shang
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Huimei Wei
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Jing Deng
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Madeline J Stewart
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Johnathan E LeSaint
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Annet Kyomuhangi
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Shawn Park
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Elise C Maul
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
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3
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Vines L, Sotelo D, Giddens N, Manza P, Volkow ND, Wang GJ. Neurological, Behavioral, and Pathophysiological Characterization of the Co-Occurrence of Substance Use and HIV: A Narrative Review. Brain Sci 2023; 13:1480. [PMID: 37891847 PMCID: PMC10605099 DOI: 10.3390/brainsci13101480] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/10/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Combined antiretroviral therapy (cART) has greatly reduced the severity of HIV-associated neurocognitive disorders in people living with HIV (PLWH); however, PLWH are more likely than the general population to use drugs and suffer from substance use disorders (SUDs) and to exhibit risky behaviors that promote HIV transmission and other infections. Dopamine-boosting psychostimulants such as cocaine and methamphetamine are some of the most widely used substances among PLWH. Chronic use of these substances disrupts brain function, structure, and cognition. PLWH with SUD have poor health outcomes driven by complex interactions between biological, neurocognitive, and social factors. Here we review the effects of comorbid HIV and psychostimulant use disorders by discussing the distinct and common effects of HIV and chronic cocaine and methamphetamine use on behavioral and neurological impairments using evidence from rodent models of HIV-associated neurocognitive impairments (Tat or gp120 protein expression) and clinical studies. We also provide a biopsychosocial perspective by discussing behavioral impairment in differentially impacted social groups and proposing interventions at both patient and population levels.
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Affiliation(s)
- Leah Vines
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA; (L.V.); (D.S.); (P.M.); (N.D.V.)
| | - Diana Sotelo
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA; (L.V.); (D.S.); (P.M.); (N.D.V.)
| | - Natasha Giddens
- Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53719, USA;
| | - Peter Manza
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA; (L.V.); (D.S.); (P.M.); (N.D.V.)
| | - Nora D. Volkow
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA; (L.V.); (D.S.); (P.M.); (N.D.V.)
| | - Gene-Jack Wang
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA; (L.V.); (D.S.); (P.M.); (N.D.V.)
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Davis SE, Cirincione AB, Jimenez-Torres AC, Zhu J. The Impact of Neurotransmitters on the Neurobiology of Neurodegenerative Diseases. Int J Mol Sci 2023; 24:15340. [PMID: 37895020 PMCID: PMC10607327 DOI: 10.3390/ijms242015340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Neurodegenerative diseases affect millions of people worldwide. Neurodegenerative diseases result from progressive damage to nerve cells in the brain or peripheral nervous system connections that are essential for cognition, coordination, strength, sensation, and mobility. Dysfunction of these brain and nerve functions is associated with Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, and motor neuron disease. In addition to these, 50% of people living with HIV develop a spectrum of cognitive, motor, and/or mood problems collectively referred to as HIV-Associated Neurocognitive Disorders (HAND) despite the widespread use of a combination of antiretroviral therapies. Neuroinflammation and neurotransmitter systems have a pathological correlation and play a critical role in developing neurodegenerative diseases. Each of these diseases has a unique pattern of dysregulation of the neurotransmitter system, which has been attributed to different forms of cell-specific neuronal loss. In this review, we will focus on a discussion of the regulation of dopaminergic and cholinergic systems, which are more commonly disturbed in neurodegenerative disorders. Additionally, we will provide evidence for the hypothesis that disturbances in neurotransmission contribute to the neuronal loss observed in neurodegenerative disorders. Further, we will highlight the critical role of dopamine as a mediator of neuronal injury and loss in the context of NeuroHIV. This review will highlight the need to further investigate neurotransmission systems for their role in the etiology of neurodegenerative disorders.
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Affiliation(s)
| | | | | | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA; (S.E.D.); (A.B.C.); (A.C.J.-T.)
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5
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Cui BC, Aksenova M, Sikirzhytskaya A, Odhiambo D, Korunova E, Sikirzhytski V, Ji H, Altomare D, Broude E, Frizzell N, Booze R, Wyatt MD, Shtutman M. Suppression of HIV and cocaine-induced neurotoxicity and inflammation by cell penetrable itaconate esters. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.25.559154. [PMID: 37808776 PMCID: PMC10557618 DOI: 10.1101/2023.09.25.559154] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
HIV-associated neurological disorder (HAND) is a serious complication of HIV infection, marked by neurotoxicity induced by viral proteins like Tat. Substance abuse exacerbates neurocognitive impairment in people living with HIV. There is an urgent need for effective therapeutic strategies to combat HAND comorbid with Cocaine Use Disorder (CUD). Our analysis of the HIV and cocaine-induced transcriptomes in primary cortical cultures revealed a significant overexpression of the macrophage-specific gene, aconitate decarboxylase 1 (Acod1), caused by the combined insults of HIV and cocaine. ACOD1 protein converts the tricarboxylic acid intermediate cis-aconitate into itaconate during the activation of inflammation. The itaconate produced facilitates cytokine production and subsequently activates anti-inflammatory transcription factors, shielding macrophages from infection-induced cell death. While the role of itaconate' in limiting inflammation has been studied in peripheral macrophages, its immunometabolic function remains unexplored in HIV and cocaine-exposed microglia. We assessed in this model system the potential of 4-octyl-itaconate (4OI), a cell-penetrable esterified form of itaconate known for its potent anti-inflammatory properties and potential therapeutic applications. We administered 4OI to primary cortical cultures exposed to Tat and cocaine. 4OI treatment increased the number of microglial cells in both untreated and Tat±Cocaine-treated cultures and also reversed the morphological altercations induced by Tat and cocaine. In the presence of 4OI, microglial cells also appeared more ramified, resembling the quiescent microglia. Consistent with these results, 4OI treatment inhibited the secretion of the proinflammatory cytokines IL-1α, IL-1β, IL-6, and MIP1-α induced by Tat and cocaine. Transcriptome profiling further determined that Nrf2 target genes such as NAD(P)H quinone oxidoreductase 1 (Nqo1), Glutathione S-transferase Pi (Gstp1), and glutamate cysteine ligase catalytic (Gclc), were most significantly activated in Tat-4OI treated cultures, relative to Tat alone. Further, genes associated with cytoskeleton dynamics in inflammatory microglia were downregulated by 4OI treatment. Together, the results strongly suggest 4-octyl-itaconate holds promise as a potential candidate for therapeutic development aimed at addressing HAND coupled with CUD comorbidities.
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Affiliation(s)
- B. Celia Cui
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Marina Aksenova
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Aliaksandra Sikirzhytskaya
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Diana Odhiambo
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Elizaveta Korunova
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Vitali Sikirzhytski
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Hao Ji
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Diego Altomare
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Eugenia Broude
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Norma Frizzell
- Department of Pharmacology, Physiology & Neuroscience, School of Medicine, University of South Carolina, Columbia, SC 29208, USA
| | - Rosemarie Booze
- Department of Psychology, College of Arts and Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Michael D. Wyatt
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Michael Shtutman
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
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6
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Davis SE, Ferris MJ, Ananthan S, Augelli-Szafran CE, Zhu J. Novel Allosteric Modulator Southern Research Institute-32743 Reverses HIV-1 Transactivator of Transcription-Induced Increase in Dopamine Release in the Caudate Putamen of Inducible Transactivator of Transcription Transgenic Mice. J Pharmacol Exp Ther 2023; 384:306-314. [PMID: 36456195 PMCID: PMC9875314 DOI: 10.1124/jpet.122.001291] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 09/30/2022] [Accepted: 11/07/2022] [Indexed: 12/04/2022] Open
Abstract
Development of neurocognitive disorder in human immunodeficiency virus (HIV)-infected patients has been linked to dysregulation of dopamine by the HIV-1 transactivator of transcription (Tat) protein, a negative allosteric modulator of dopamine transporter (DAT). Using fast scan cyclic voltammetry, the present study determined the effects of in vivo Tat expression on dopamine release in the caudate putamen of inducible Tat transgenic (iTat-tg) mice and the impact of a novel DAT allosteric modulator, Southern Research Institute (SRI)-32743, on the Tat effect. We found that 7- or 14-day doxycycline (Dox)-induced Tat expression in iTat-tg mice resulted in a 2-fold increase in phasic but not tonic stimulated baseline dopamine release relative to saline control mice. To determine whether the Tat-induced increase in dopamine release is mediated by DAT regulation, we examined the effect of an in vitro applied DAT inhibitor, nomifensine, on the dopamine release. Nomifensine (1 nM-10 µM) concentration-dependently enhanced phasic stimulated dopamine release in both saline- and Dox-treated iTat-tg mice, while the magnitude of the nomifensine-mediated dopamine release was unchanged between saline and Dox treatment groups. A single systemic administration of SRI-32743 prior to animal sacrifice reversed the increased dopamine release in the baseline of phasic dopamine release and nomifensine-augmented dopamine levels in Dox-treated iTat-tg mice, while SRI-32743 alone did not alter baseline of dopamine release. These findings suggest that Tat expression induced an increase in extracellular dopamine levels by not only inhibiting DAT-mediated dopamine transport but also stimulating synaptic dopamine release. Thus, DAT allosteric modulators may serve as a potential therapeutic intervention for HIV infection-dysregulated dopamine system observed in HIV-1 positive individuals. SIGNIFICANCE STATEMENT: HIV infection-induced dysregulation of the dopaminergic system has been implicated in the development of neurocognitive impairments observed in HIV positive patients. Understanding the mechanisms underlying HIV-1 Tat protein-induced alteration of extracellular dopamine levels will provide insights into the development of molecules that can attenuate Tat interaction with targets in the dopaminergic system. Here, we determined whether Tat alters dopamine release and how the novel DAT allosteric modulator, SRI-32743, impacts dopamine neurotransmission to attenuate Tat-induced effects on extracellular dopamine dynamics.
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Affiliation(s)
- Sarah E Davis
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina (S.E.D., J.Z.); Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina (M.M.F.); and Department of Chemistry, Scientific Platforms, Southern Research, Birmingham, Alabama (S.A., C.E.A.)
| | - Mark J Ferris
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina (S.E.D., J.Z.); Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina (M.M.F.); and Department of Chemistry, Scientific Platforms, Southern Research, Birmingham, Alabama (S.A., C.E.A.)
| | - Subramaniam Ananthan
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina (S.E.D., J.Z.); Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina (M.M.F.); and Department of Chemistry, Scientific Platforms, Southern Research, Birmingham, Alabama (S.A., C.E.A.)
| | - Corinne E Augelli-Szafran
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina (S.E.D., J.Z.); Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina (M.M.F.); and Department of Chemistry, Scientific Platforms, Southern Research, Birmingham, Alabama (S.A., C.E.A.)
| | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina (S.E.D., J.Z.); Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina (M.M.F.); and Department of Chemistry, Scientific Platforms, Southern Research, Birmingham, Alabama (S.A., C.E.A.)
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Ghanam RH, Eastep GN, Saad JS. Structural Insights into the Mechanism of HIV-1 Tat Secretion from the Plasma Membrane. J Mol Biol 2023; 435:167880. [PMID: 36370804 PMCID: PMC9822876 DOI: 10.1016/j.jmb.2022.167880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/27/2022] [Accepted: 11/04/2022] [Indexed: 11/11/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) trans-activator of transcription (Tat) is a small, intrinsically disordered basic protein that plays diverse roles in the HIV-1 replication cycle, including promotion of efficient viral RNA transcription. Tat is released by infected cells and subsequently absorbed by healthy cells, thereby contributing to HIV-1 pathogenesis including HIV-associated neurocognitive disorder. It has been shown that, in HIV-1-infected primary CD4 T-cells, Tat accumulates at the plasma membrane (PM) for secretion, a mechanism mediated by phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). However, the structural basis for Tat interaction with the PM and thereby secretion is lacking. Herein, we employed NMR and biophysical methods to characterize Tat86 (86 amino acids) interactions with PI(4,5)P2 and lipid nanodiscs (NDs). Our data revealed that Arg49, Lys50 and Lys51 (RKK motif) constitute the PI(4,5)P2 binding site, that Tat86 interaction with lipid NDs is dependent on PI(4,5)P2 and phosphatidylserine (PS), and that the arginine-rich motif (RRQRRR) preferentially interacts with PS. Furthermore, we show that Trp11, previously implicated in Tat secretion, penetrates deeply in the membrane; substitution of Trp11 severely reduced Tat86 interaction with membranes. Deletion of the entire highly basic region and Trp11 completely abolished Tat86 binding to lipid NDs. Our data support a mechanism by which HIV-1 Tat secretion from the PM is mediated by a tripartite signal consisting of binding of the RKK motif to PI(4,5)P2, arginine-rich motif to PS, and penetration of Trp11 in the membrane. Altogether, these findings provide new insights into the molecular requirements for Tat binding to membranes during secretion.
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Affiliation(s)
- Ruba H Ghanam
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Gunnar N Eastep
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Jamil S Saad
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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8
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Nepal B, Das S, Reith ME, Kortagere S. Overview of the structure and function of the dopamine transporter and its protein interactions. Front Physiol 2023; 14:1150355. [PMID: 36935752 PMCID: PMC10020207 DOI: 10.3389/fphys.2023.1150355] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 02/21/2023] [Indexed: 03/06/2023] Open
Abstract
The dopamine transporter (DAT) plays an integral role in dopamine neurotransmission through the clearance of dopamine from the extracellular space. Dysregulation of DAT is central to the pathophysiology of numerous neuropsychiatric disorders and as such is an attractive therapeutic target. DAT belongs to the solute carrier family 6 (SLC6) class of Na+/Cl- dependent transporters that move various cargo into neurons against their concentration gradient. This review focuses on DAT (SCL6A3 protein) while extending the narrative to the closely related transporters for serotonin and norepinephrine where needed for comparison or functional relevance. Cloning and site-directed mutagenesis experiments provided early structural knowledge of DAT but our contemporary understanding was achieved through a combination of crystallization of the related bacterial transporter LeuT, homology modeling, and subsequently the crystallization of drosophila DAT. These seminal findings enabled a better understanding of the conformational states involved in the transport of substrate, subsequently aiding state-specific drug design. Post-translational modifications to DAT such as phosphorylation, palmitoylation, ubiquitination also influence the plasma membrane localization and kinetics. Substrates and drugs can interact with multiple sites within DAT including the primary S1 and S2 sites involved in dopamine binding and novel allosteric sites. Major research has centered around the question what determines the substrate and inhibitor selectivity of DAT in comparison to serotonin and norepinephrine transporters. DAT has been implicated in many neurological disorders and may play a role in the pathology of HIV and Parkinson's disease via direct physical interaction with HIV-1 Tat and α-synuclein proteins respectively.
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Affiliation(s)
- Binod Nepal
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Sanjay Das
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Maarten E. Reith
- Department of Psychiatry, New York University School of Medicine, New York City, NY, United States
| | - Sandhya Kortagere
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States
- *Correspondence: Sandhya Kortagere,
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SRI-32743, a novel allosteric modulator, attenuates HIV-1 Tat protein-induced inhibition of the dopamine transporter and alleviates the potentiation of cocaine reward in HIV-1 Tat transgenic mice. Neuropharmacology 2022; 220:109239. [PMID: 36126727 DOI: 10.1016/j.neuropharm.2022.109239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 08/09/2022] [Accepted: 09/01/2022] [Indexed: 11/21/2022]
Abstract
Cocaine abuse increases the incidence of HIV-1-associated neurocognitive disorders. We have demonstrated that HIV-1 transactivator of transcription (Tat) allosterically modulates dopamine (DA) reuptake through the human DA transporter (hDAT), potentially contributing to Tat-induced cognitive impairment and potentiation of cocaine conditioned place preference (CPP). This study determined the effects of a novel allosteric modulator of DAT, SRI-32743, on the interactions of HIV-1 Tat, DA, cocaine, and [3H]WIN35,428 with hDAT in vitro. SRI-32743 (50 nM) attenuated Tat-induced inhibition of [3H]DA uptake and decreased the cocaine-mediated dissociation of [3H]WIN35,428 binding in CHO cells expressing hDAT, suggesting a SRI-32743-mediated allosteric modulation of the Tat-DAT interaction. In further in vivo studies utilizing doxycycline-inducible Tat transgenic (iTat-tg) mice, 14 days of Tat expression significantly reduced the recognition index by 31.7% in the final phase of novel object recognition (NOR) and potentiated cocaine-CPP 2.7-fold compared to responses of vehicle-treated control iTat-tg mice. The Tat-induced NOR deficits and potentiation of cocaine-CPP were not observed in saline-treated iTat-tg or doxycycline-treated G-tg (Tat-null) mice. Systemic administration (i.p.) of SRI-32743 prior to behavioral testing ameliorated Tat-induced impairment of NOR (at a dose of 10 mg/kg) and the Tat-induced potentiation of cocaine-CPP (at doses of 1 or 10 mg/kg). These findings demonstrate that Tat and cocaine interactions with DAT may be regulated by compounds interacting at the DAT allosteric modulatory sites, suggesting a potential therapeutic intervention for HIV-infected patients with concurrent cocaine abuse.
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Strauss MJ, Porter KD, Quizon PM, Davis SE, Lin S, Yuan Y, Martinez-Muniz GA, Sun WL, Zhan CG, Zhu J. Mutations of tyrosine 467 in the human norepinephrine transporter attenuate HIV-1 Tat-induced inhibition of dopamine transport while retaining physiological function. PLoS One 2022; 17:e0275182. [PMID: 36170295 PMCID: PMC9518868 DOI: 10.1371/journal.pone.0275182] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 09/12/2022] [Indexed: 11/18/2022] Open
Abstract
Dysregulation of dopaminergic transmission induced by the HIV-1 transactivator of transcription (Tat) has been implicated as a central factor in the development of HIV-1 associated neurocognitive disorders (HAND). We have demonstrated that the tyrosine470 residue of the human dopamine transporter (hDAT) plays a critical role in Tat-hDAT interaction. Based on the computational modeling predictions, the present study sought to examine the mutational effects of the tyrosine467 residue of the human norepinephrine transporter (hNET), a corresponding residue of the hDAT tyrosine470, on Tat-induced inhibition of reuptake of dopamine through the hNET. Mutations of the hNET tyrosine467 to a histidine (Y467H) or a phenylalanine (Y467F) displayed similar kinetic properties of reuptake of [3H]dopamine and [3H]norepinephrine in PC12 cells expressing wild-type hNET and its mutants. Compared to wild-type hNET, neither of Y467H or Y467F altered Bmax and Kd values of [3H]WIN35,428 binding, whereas Y467H but not Y467F decreased the Bmax of [3H]nisoxetine binding without changes in Kd. Y467H also increased the affinity of nisoxetine for inhibiting [3H]dopamine uptake relative to wild-type hNET. Recombinant Tat1-86 (140 nM) induced a significant reduction of [3H]dopamine uptake in wild-type hNET, which was attenuated in both Y467H and Y467F. Compared to wild-type hNET, neither Y467H or Y467F altered [3H]dopamine efflux in CHO cells expressing WT hNET and mutants, whereas Y467F but not Y467H decreased [3H]MPP+ efflux. These results demonstrate tyrosine467 as a functional recognition residue in the hNET for Tat-induced inhibition of dopamine transport and provide a novel insight into the molecular basis for developing selective compounds that target Tat-NET interactions in the context of HAND.
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Affiliation(s)
- Matthew J. Strauss
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States of America
| | - Katherine D. Porter
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States of America
| | - Pamela M. Quizon
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States of America
| | - Sarah E. Davis
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States of America
| | - Steven Lin
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States of America
| | - Yaxia Yuan
- Molecular Modeling and Biopharmaceutical Center, University of Kentucky, Lexington, KY, United States of America
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, United States of America
| | - Gustavo A. Martinez-Muniz
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States of America
| | - Wei-Lun Sun
- Department of Psychological Science, University of North Georgia, Dahlonega, GA, United States of America
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, University of Kentucky, Lexington, KY, United States of America
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, United States of America
| | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States of America
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Zheng F, Jin Z, Deng J, Chen X, Zheng X, Wang G, Kim K, Shang L, Zhou Z, Zhan CG. Development of a Highly Efficient Long-Acting Cocaine Hydrolase Entity to Accelerate Cocaine Metabolism. Bioconjug Chem 2022; 33:1340-1349. [PMID: 35767675 DOI: 10.1021/acs.bioconjchem.2c00210] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is particularly challenging to develop a truly effective pharmacotherapy for cocaine use disorder (CUD) treatment. Accelerating cocaine metabolism via hydrolysis at cocaine benzoyl ester using an efficient cocaine hydrolase (CocH) is known as a promising pharmacotherapeutic approach to CUD treatment. Preclinical and clinical studies on our first CocH (CocH1), in its human serum albumin-fused form known as TV-1380, have demonstrated the promise of a general concept of CocH-based pharmacotherapy for CUD treatment. However, the biological half-life of TV-1380 (t1/2 = 8 h in rats, associated with t1/2 = 43-77 h in humans) is not long enough for practical treatment of cocaine dependence, which requires enzyme injection for no more than once weekly. Through protein fusion of a human butyrylcholinesterase mutant (denoted as CocH5) with a mutant (denoted as Fc(M6)) of Fc from human IgG1, we have designed, prepared, and tested a new fusion protein (denoted as CocH5-Fc(M6)) for its pharmacokinetic profile and in vivo catalytic activity against (-)-cocaine. CocH5-Fc(M6) represents the currently most efficient long-acting cocaine hydrolase with both the highest catalytic activity against (-)-cocaine and the longest elimination half-life (t1/2 = 229 ± 5 h) in rats. As a result, even at a single modest dose of 3 mg/kg, CocH5-Fc(M6) can significantly and effectively accelerate the metabolism of cocaine in rats for at least 60 days. In addition, ∼70 nM CocH5-Fc(M6) in plasma was able to completely block the toxicity and physiological effects induced by intraperitoneal injection of a lethal dose of cocaine (60 mg/kg).
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12
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Mori L, Valente ST. Cure and Long-Term Remission Strategies. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2407:391-428. [PMID: 34985678 DOI: 10.1007/978-1-0716-1871-4_26] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The majority of virally suppressed individuals will experience rapid viral rebound upon antiretroviral therapy (ART) interruption, providing a strong rationale for the development of cure strategies. Moreover, despite ART virological control, HIV infection is still associated with chronic immune activation, inflammation, comorbidities, and accelerated aging. These effects are believed to be due, in part, to low-grade persistent transcription and trickling production of viral proteins from the pool of latent proviruses constituting the viral reservoir. In recent years there has been an increasing interest in developing what has been termed a functional cure for HIV. This approach entails the long-term, durable control of viral expression in the absence of therapy, preventing disease progression and transmission, despite the presence of detectable integrated proviruses. One such strategy, the block-and-lock approach for a functional cure, proposes the epigenetic silencing of proviral expression, locking the virus in a profound latent state, from which reactivation is very unlikely. The proof-of-concept for this approach was demonstrated with the use of a specific small molecule targeting HIV transcription. Here we review the principles behind the block-and-lock approach and some of the additional strategies proposed to silence HIV expression.
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Affiliation(s)
- Luisa Mori
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA
| | - Susana T Valente
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA.
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13
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Jones CB, Dukat M. Review of 3D templates for in silico homology models of MATs: improved 3D model of hDAT. Med Chem Res 2022. [DOI: 10.1007/s00044-022-02863-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Davis S, Zhu J. Substance abuse and neurotransmission. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 93:403-441. [PMID: 35341573 PMCID: PMC9759822 DOI: 10.1016/bs.apha.2021.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The number of people who suffer from a substance abuse disorder has continued to rise over the last decade; particularly, the number of drug-related overdose deaths has sharply increased during the COVID-19 pandemic. Converging lines of clinical observations, supported by imaging and neuropsychological performance testing, have demonstrated that substance abuse-induced dysregulation of neurotransmissions in the brain is critical for development and expression of the addictive properties of abused substances. Recent scientific advances have allowed for better understanding of the neurobiological processes that mediates drugs of abuse and addiction. This chapter presents the past classic concepts and the recent advances in our knowledge about how cocaine, amphetamines, opioids, alcohol, and nicotine alter multiple neurotransmitter systems, which contribute to the behaviors associated with each drug. Additionally, we discuss the interactive effects of HIV-1 or COVID-19 and substance abuse on neurotransmission and neurobiological pathways. Finally, we introduce therapeutic strategies for development of pharmacotherapies for substance abuse disorders.
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Affiliation(s)
- Sarah Davis
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States
| | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, United States.
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15
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League AF, Gorman BL, Hermes DJ, Johnson CT, Jacobs IR, Yadav-Samudrala BJ, Poklis JL, Niphakis MJ, Cravatt BF, Lichtman AH, Ignatowska-Jankowska BM, Fitting S. Monoacylglycerol Lipase Inhibitor MJN110 Reduces Neuronal Hyperexcitability, Restores Dendritic Arborization Complexity, and Regulates Reward-Related Behavior in Presence of HIV-1 Tat. Front Neurol 2021; 12:651272. [PMID: 34484091 PMCID: PMC8415271 DOI: 10.3389/fneur.2021.651272] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 07/12/2021] [Indexed: 12/01/2022] Open
Abstract
While current therapeutic strategies for people living with human immunodeficiency virus type 1 (HIV-1) suppress virus replication peripherally, viral proteins such as transactivator of transcription (Tat) enter the central nervous system early upon infection and contribute to chronic inflammatory conditions even alongside antiretroviral treatment. As demand grows for supplemental strategies to combat virus-associated pathology presenting frequently as HIV-associated neurocognitive disorders (HAND), the present study aimed to characterize the potential utility of inhibiting monoacylglycerol lipase (MAGL) activity to increase inhibitory activity at cannabinoid receptor-type 1 receptors through upregulation of 2-arachidonoylglycerol (2-AG) and downregulation of its degradation into proinflammatory metabolite arachidonic acid (AA). The MAGL inhibitor MJN110 significantly reduced intracellular calcium and increased dendritic branching complexity in Tat-treated primary frontal cortex neuron cultures. Chronic MJN110 administration in vivo increased 2-AG levels in the prefrontal cortex (PFC) and striatum across Tat(+) and Tat(–) groups and restored PFC N-arachidonoylethanolamine (AEA) levels in Tat(+) subjects. While Tat expression significantly increased rate of reward-related behavioral task acquisition in a novel discriminative stimulus learning and cognitive flexibility assay, MJN110 altered reversal acquisition specifically in Tat(+) mice to rates indistinguishable from Tat(–) controls. Collectively, our results suggest a neuroprotective role of MAGL inhibition in reducing neuronal hyperexcitability, restoring dendritic arborization complexity, and mitigating neurocognitive alterations driven by viral proteins associated with latent HIV-1 infection.
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Affiliation(s)
- Alexis F League
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, Chapel Hill, NC, United States
| | - Benjamin L Gorman
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, Chapel Hill, NC, United States
| | - Douglas J Hermes
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, Chapel Hill, NC, United States
| | - Clare T Johnson
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, Chapel Hill, NC, United States
| | - Ian R Jacobs
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, Chapel Hill, NC, United States
| | - Barkha J Yadav-Samudrala
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, Chapel Hill, NC, United States
| | - Justin L Poklis
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Micah J Niphakis
- Department of Chemistry, Scripps Research Institute, La Jolla, CA, United States
| | - Benjamin F Cravatt
- Department of Chemistry, Scripps Research Institute, La Jolla, CA, United States
| | - Aron H Lichtman
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | | | - Sylvia Fitting
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, Chapel Hill, NC, United States
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Adeniran C, Yuan Y, Davis SE, Lin C, Xu J, Zhu J, Zhan CG. Binding Mode of Human Norepinephrine Transporter Interacting with HIV-1 Tat. ACS Chem Neurosci 2021; 12:1519-1527. [PMID: 33886267 PMCID: PMC8562539 DOI: 10.1021/acschemneuro.0c00792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The increase of HIV infection in macrophages results in HIV proteins being released, like HIV Tat which impairs the function of monoamine transporters. HIV-infected patients have displayed increased synaptic levels of dopamine (DA) due to reduced binding and function of monoamine transporters such as the norepinephrine transporter (NET) and the dopamine transporter (DAT). Development of a three-dimensional model of the HIV-1 Tat-human NET (hNET) binding complex would help reveal how HIV-1 Tat causes toxicity in the neuron by affecting DA uptake. Here we use computational techniques such as molecular modeling to study microscopic properties and molecular dynamics of the HIV-1 Tat-hNET binding. These modeling techniques allow us to analyze noncovalent interactions and observe residue-residue contacts to verify a model structure. The modeling results studied here show that HIV-1 Tat-hNET binding is highly dynamic and that HIV-1 Tat preferentially binds to hNET in its outward-open state. In particular, HIV-1 Tat forms hydrogen bond interactions with side chains of hNET residues Y84, K88, and T544. The favorable hydrogen bonding interactions of HIV-1 Tat with the hNET side chain residues Y84 and T544 have been validated by our subsequently performed DA uptake activity assays and site-directed mutagenesis, suggesting that the modeled HIV-1 Tat-hNET binding mode is reasonable. These mechanistic and structural insights gained through homology models discussed in this study are expected to encourage the pursuit of pharmacological and biochemical studies on HIV-1 Tat interacting with hNET mechanisms and detailed structures.
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Affiliation(s)
- Charles Adeniran
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, KY 40506
| | - Yaxia Yuan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
| | - Sarah E. Davis
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208
| | - Ciai Lin
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208
| | - Jiahui Xu
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208
| | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
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Mutations of Human DopamineTransporter at Tyrosine88, Aspartic Acid206, and Histidine547 Influence Basal and HIV-1 Tat-inhibited Dopamine Transport. J Neuroimmune Pharmacol 2021; 16:854-869. [PMID: 33537927 PMCID: PMC8329121 DOI: 10.1007/s11481-021-09984-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/13/2021] [Indexed: 12/14/2022]
Abstract
HIV-1 transactivator of transcription (Tat) has a great impact on the development of HIV-1 associated neurocognitive disorders through disrupting dopamine transmission. This study determined the mutational effects of human dopamine transporter (hDAT) on basal and Tat-induced inhibition of dopamine transport. Compared to wild-type hDAT, the maximal velocity (Vmax) of [3H]dopamine uptake was decreased in D381L and Y88F/D206L/H547A, increased in D206L/H547A, and unaltered in D206L. Recombinant TatR1 − 86 inhibited dopamine uptake in wild-type hDAT, which was attenuated in either DAT mutants (D206L, D206L/H547A, and Y88F/D206L/H547A) or mutated TatR1 − 86 (K19A and C22G), demonstrating perturbed Tat-DAT interaction. Mutational effects of hDAT on the transporter conformation were evidenced by attenuation of zinc-induced increased [3H]WIN35,428 binding in D206L/H547A and Y88F/D206A/H547A and enhanced basal MPP+ efflux in D206L/H547A. H547A-induced outward-open transport conformational state was further validated by enhanced accessibility to MTSET ([2-(trimethylammonium)ethyl]-methanethiosulfonate) of an inserted cysteine (I159C) on a hDAT background.. Furthermore, H547A displayed an increase in palmitoylation inhibitor-induced inhibition of dopamine uptake relative to wide-type hDAT, indicating a change in basal palmitoylation in H547A. These results demonstrate that Y88F, D206L, and H547A attenuate Tat inhibition while preserving DA uptake, providing insights into identifying targets for improving DAT-mediated dopaminergic dysregulation.
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Balance between Retroviral Latency and Transcription: Based on HIV Model. Pathogens 2020; 10:pathogens10010016. [PMID: 33383617 PMCID: PMC7824405 DOI: 10.3390/pathogens10010016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 01/04/2023] Open
Abstract
The representative of the Lentivirus genus is the human immunodeficiency virus type 1 (HIV-1), the causative agent of acquired immunodeficiency syndrome (AIDS). To date, there is no cure for AIDS because of the existence of the HIV-1 reservoir. HIV-1 infection can persist for decades despite effective antiretroviral therapy (ART), due to the persistence of infectious latent viruses in long-lived resting memory CD4+ T cells, macrophages, monocytes, microglial cells, and other cell types. However, the biology of HIV-1 latency remains incompletely understood. Retroviral long terminal repeat region (LTR) plays an indispensable role in controlling viral gene expression. Regulation of the transcription initiation plays a crucial role in establishing and maintaining a retrovirus latency. Whether and how retroviruses establish latency and reactivate remains unclear. In this article, we describe what is known about the regulation of LTR-driven transcription in HIV-1, that is, the cis-elements present in the LTR, the role of LTR transcription factor binding sites in LTR-driven transcription, the role of HIV-1-encoded transactivator protein, hormonal effects on virus transcription, impact of LTR variability on transcription, and epigenetic control of retrovirus LTR. Finally, we focus on a novel clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/dCas9)-based strategy for HIV-1 reservoir purging.
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Clinical potential of a rationally engineered enzyme for treatment of cocaine dependence: Long-lasting blocking of the psychostimulant, discriminative stimulus, and reinforcing effects of cocaine. Neuropharmacology 2020; 176:108251. [PMID: 32710979 DOI: 10.1016/j.neuropharm.2020.108251] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 02/06/2023]
Abstract
It is a grand challenge to develop a truly effective treatment of substance use disorder (SUD), particularly for cocaine and other drugs without an FDA-approved treatment available, because a truly effective therapy must effectively block the drug's physiological and reinforcing effects during the entire period of treatment in order to achieve the long-time abstinence required by the FDA. Whether a biologic, such as monoclonal antibody, vaccine, or therapeutic enzyme, can be truly effective for SUD treatment or not has been the subject of extensive debate. The main debate question is whether a biologic, particularly an exogenous enzyme, can effectively block the drug's reinforcing effect. In this report, we demonstrate that a modest dose of a recently redesigned long-acting cocaine hydrolase, CocH3-Fc(M6), can be used to effectively block the psychostimulant, discriminative stimulus, and reinforcing effects of cocaine for a sufficiently long period of time. For example, a dose of 3 mg/kg CocH3-Fc(M6) completely blocked the discriminative stimulus and reinforcing effects for 24/25 days and continued to significantly attenuate/decrease the cocaine effects for at least 29 days in rats. All the animal data consistently suggest that the long-acting cocaine hydrolase is a truly promising candidate of enzyme therapy for treatment of cocaine use disorder.
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Strauss M, O'Donovan B, Ma Y, Xiao Z, Lin S, Bardo MT, Ortinski PI, McLaughlin JP, Zhu J. [ 3H]Dopamine Uptake through the Dopamine and Norepinephrine Transporters is Decreased in the Prefrontal Cortex of Transgenic Mice Expressing HIV-1 Transactivator of Transcription Protein. J Pharmacol Exp Ther 2020; 374:241-251. [PMID: 32461322 DOI: 10.1124/jpet.120.266023] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/21/2020] [Indexed: 01/16/2023] Open
Abstract
Dysregulation of dopamine neurotransmission has been linked to the development of human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND). To investigate the mechanisms underlying this phenomenon, this study used an inducible HIV-1 transactivator of transcription (Tat) transgenic (iTat-tg) mouse model, which demonstrates brain-specific Tat expression induced by administration of doxycycline. We found that induction of Tat expression in the iTat-tg mice for either 7 or 14 days resulted in a decrease (∼30%) in the V max of [3H]dopamine uptake via both the dopamine transporter (DAT) and norepinephrine transporter (NET) in the prefrontal cortex (PFC), which was comparable to the magnitude (∼35%) of the decrease in B max for [3H]WIN 35,428 and [3H]nisoxetine binding to DAT and NET, respectively. The decreased V max was not accompanied by a reduction of total or plasma membrane expression of DAT and NET. Consistent with the decreased V max for DAT and NET in the PFC, the current study also found an increase in the tissue content of DA and dihydroxyphenylacetic acid in the PFC of iTat-tg mice after 7 days' administration of doxycycline. Electrophysiological recordings in layer V pyramidal neurons of the prelimbic cortex from iTat-tg mice found a significant reduction in action potential firing, which was not sensitive to selective inhibitors for DAT and NET, respectively. These findings provide a molecular basis for using the iTat-tg mouse model in the studies of NeuroHIV. Determining the mechanistic basis underlying the interaction between Tat and DAT/NET may reveal novel therapeutic possibilities for preventing the increase in comorbid conditions as well as HAND. SIGNIFICANCE STATEMENT: Human immunodeficiency virus (HIV)-1 infection disrupts dopaminergic neurotransmission, leading to HIV-associated neurocognitive disorders (HANDs). Based on our in vitro and in vivo studies, dopamine uptake via both dopamine and norepinephrine transporters is decreased in the prefrontal cortex of HIV-1 Tat transgenic mice, which is consistent with the increased dopamine and dihydroxyphenylacetic acid contents in this brain region. Thus, these plasma membrane transporters are an important potential target for therapeutic intervention for patients with HAND.
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Affiliation(s)
- Matthew Strauss
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
| | - Bernadette O'Donovan
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
| | - Yizhi Ma
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
| | - Ziyu Xiao
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
| | - Steven Lin
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
| | - Michael T Bardo
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
| | - Pavel I Ortinski
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
| | - Jay P McLaughlin
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
| | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (M.S., Y.M., Z.X., S.L., J.Z.) and Department of Physiology, Pharmacology and Neuroscience, School of Medicine (B.O.), University of South Carolina, Columbia, South Carolina; Departments of Psychology (M.B.) and Neuroscience (P.O.), University of Kentucky, Lexington, Kentucky; and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (J.M.)
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21
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Zheng F, Chen X, Kim K, Zhang T, Huang H, Zhou S, Zhang J, Jin Z, Zhan CG. Structure-Based Design and Discovery of a Long-Acting Cocaine Hydrolase Mutant with Improved Binding Affinity to Neonatal Fc Receptor for Treatment of Cocaine Abuse. AAPS JOURNAL 2020; 22:62. [PMID: 32189158 DOI: 10.1208/s12248-020-00442-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 02/28/2020] [Indexed: 01/06/2023]
Abstract
Despite decades of efforts to develop a pharmacotherapy for cocaine abuse treatment, there is still no FDA-approved treatment of diseases associated with this commonly abused drug. Our previously designed highly efficient cocaine hydrolases (CocHs) and the corresponding Fc-fusion proteins (e.g., CocH3-Fc) are recognized as potentially promising therapeutic enzyme candidates for cocaine abuse treatment, but all with limited biological half-lives. In order to prolong the biological half-life and, thus, decrease the required frequency of the enzyme administration for cocaine abuse treatment, we have modeled the Fc-fusion CocH binding with neonatal Fc receptor (FcRn) in the present study. This approach led to the design and testing of CocH3-Fc(M6), a CocH3-Fc mutant with nearly 100-fold increased binding affinity: from Kd = ~ 4 μM to Kd = 43 nM. As a result, CocH3-Fc(M6) indeed revealed a markedly prolonged biological half-life (t1/2 = 206 ± 7 h or ~ 9 days) in rats, longer than other known Fc-fusion protein drugs such as abatacept and alefacept (for other therapeutic purposes) in the same species (rats). It has been demonstrated that a single dose of 3 mg/kg CocH3-Fc(M6) effectively blocked 20 mg/kg cocaine-induced hyperactivity on day 18 after CocH3-Fc(M6) administration. This is the first attempt to rationally design long-acting Fc-fusion enzyme mutant based on combined computational modeling and experimental measurement of the Fc-fusion CocH binding with FcRn. The similar structure-based design strategy may be used to prolong the biological half-lives of other Fc-fusion protein drugs.
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Affiliation(s)
- Fang Zheng
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Xiabin Chen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Kyungbo Kim
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Ting Zhang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Haifeng Huang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Shuo Zhou
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Jinling Zhang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Zhenyu Jin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA. .,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA.
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22
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Mohseni Ahooyi T, Torkzaban B, Shekarabi M, Tahrir FG, Decoppet EA, Cotto B, Langford D, Amini S, Khalili K. Perturbation of synapsins homeostasis through HIV-1 Tat-mediated suppression of BAG3 in primary neuronal cells. Cell Death Dis 2019; 10:473. [PMID: 31209204 PMCID: PMC6572798 DOI: 10.1038/s41419-019-1702-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/06/2019] [Accepted: 03/14/2019] [Indexed: 02/02/2023]
Abstract
HIV-1 Tat is known to be released by HIV infected non-neuronal cells in the brain, and after entering neurons, compromises brain homeostasis by impairing pro-survival pathways, thus contributing to the development of HIV-associated CNS disorders commonly observed in individuals living with HIV. Here, we demonstrate that synapsins, phosphoproteins that are predominantly expressed in neuronal cells and play a vital role in modulating neurotransmitter release at the pre-synaptic terminal, and neuronal differentiation become targets for Tat through autophagy and protein quality control pathways. We demonstrate that the presence of Tat in neurons results in downregulation of BAG3, a co-chaperone for heat shock proteins (Hsp70/Hsc70) that is implicated in protein quality control (PQC) processes by eliminating mis-folded and damaged proteins, and selective macroautophagy. Our results show that treatment of cells with Tat or suppression of BAG3 expression by siRNA in neuronal cells disturbs subcellular distribution of synapsins and synaptotagmin 1 (Syt1) leading to their accumulation in the neuronal soma and along axons in a punctate pattern, rather than being properly distributed at axon-terminals. Further, our results revealed that synapsins partially lost their stability and their removal via lysosomal autophagy was noticeably impaired in cells with low levels of BAG3. The observed impairment of lysosomal autophagy, under this condition, is likely caused by cells losing their ability to process LC3-I to LC3-II, in part due to a decrease in the ATG5 levels upon BAG3 knockdown. These observations ascribe a new function for BAG3 in controlling synaptic communications and illuminate a new downstream target for Tat to elicit its pathogenic effect in impacting neuronal cell function and behavior.
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Affiliation(s)
- Taha Mohseni Ahooyi
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA.
| | - Bahareh Torkzaban
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Masoud Shekarabi
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Farzaneh G Tahrir
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Emilie A Decoppet
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Bianca Cotto
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Dianne Langford
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Shohreh Amini
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Kamel Khalili
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA.
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23
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Mutational effects of human dopamine transporter at tyrosine88, lysine92, and histidine547 on basal and HIV-1 Tat-inhibited dopamine transport. Sci Rep 2019; 9:3843. [PMID: 30846720 PMCID: PMC6405875 DOI: 10.1038/s41598-019-39872-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/12/2018] [Indexed: 01/06/2023] Open
Abstract
Dysregulation of dopaminergic system induced by HIV-1 Tat protein-mediated direct inhibition of the dopamine transporter (DAT) has been implicated as a mediating factor of HIV-1 associated neurocognitive disorders. We have reported that single point mutations on human DAT (hDAT) at tyrosine88 (Y88F), lysine92 (K92M), and histidine547 (H547A) differentially regulate basal dopamine uptake but diminish Tat-induced inhibition of dopamine uptake by changing dopamine transport process. This study evaluated the effects of double (Y88F/H547A) and triple (Y88F/K92M/H547A) mutations on basal dopamine uptake, Tat-induced inhibition of DAT function, and dynamic transport process. Compared to wild-type hDAT, the Vmax values of [3H]Dopamine uptake were increased by 96% in Y88F/H547A but decreased by 97% in Y88F/K92M/H547A. [3H]WIN35,428 binding sites were not altered in Y88F/H547A but decreased in Y88F/K92M/H547A. Y88F/H547A mutant attenuated Tat-induced inhibition of dopamine uptake observed in wild-type hDAT. Y88F/H547A displayed an attenuation of zinc-augmented [3H]WIN35,428 binding, increased basal dopamine efflux, and reduced amphetamine-induced dopamine efflux, indicating this mutant alters transporter conformational transitions. These findings further demonstrate that both tyrosine88 and histidine547 on hDAT play a key role in stabilizing basal dopamine transport and Tat-DAT integration. This study provides mechanistic insights into developing small molecules to block multiple sites in DAT for Tat binding.
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24
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Mohseni Ahooyi T, Shekarabi M, Decoppet EA, Langford D, Khalili K, Gordon J. Network analysis of hippocampal neurons by microelectrode array in the presence of HIV-1 Tat and cocaine. J Cell Physiol 2018; 233:9299-9311. [PMID: 29206302 DOI: 10.1002/jcp.26322] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 11/27/2017] [Indexed: 12/18/2022]
Abstract
HIV-associated neurocognitive disorders affecting greater than 30% of patients are caused by HIV-1 infection of the CNS, and in part, include neurotoxic effects of the viral transactivator of transcription, Tat protein. In addition to increasing the risk for becoming HIV infected, cocaine abuse enhances the neuropathogenic impacts of HIV-1. To investigate the outcome of Tat and cocaine interference in the hippocampal neuronal network, cross-rank-corrlation was employed to develop a systematic framework to assess hippocampal neurons behavior cultured on multielectrode arrays. Tat and cocaine differentially disturbed neuronal spiking rates, amplitude, synchronous activity, and oscillations within the hippocampal neuronal network via potentiation of inhibitory neurotransmission. The Tat-mediated impairment of neuronal spiking was reversible by removal of Tat, which restored neuronal activity. The presence of astrocytes co-cultured with neuronal networks diminished the effects of Tat and cocaine on neuron function suggesting a role for astrocytes in stabilizing neuronal behavior and increasing neuronal spontaneous activities such as bursting amplitude, frequency, and wave propagation rate. Taken together, our studies indicate that the HIV protein Tat and cocaine impair hippocampal neuronal network functioning and that the presence of astrocytes alleviates network dysfunction pointing to a newly discovered pathway through which ionic homeostasis is maintained by neuron-glial crosstalk in the CNS.
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Affiliation(s)
- Taha Mohseni Ahooyi
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Masoud Shekarabi
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Emilie A Decoppet
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Dianne Langford
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Kamel Khalili
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Jennifer Gordon
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
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25
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Yuan Y, Zhu J, Zhan CG. Flipped Phenyl Ring Orientations of Dopamine Binding with Human and Drosophila Dopamine Transporters: Remarkable Role of Three Nonconserved Residues. ACS Chem Neurosci 2018; 9:1426-1431. [PMID: 29494767 DOI: 10.1021/acschemneuro.8b00030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Molecular modeling and molecular dynamics simulations were performed in the present study to examine the modes of dopamine binding with human and Drosophila dopamine transporters (hDAT and dDAT). The computational data revealed flipped binding orientations of dopamine in hDAT and dDAT due to the major differences in three key residues (S149, G153, and A423 of hDAT vs A117, D121, and S422 of dDAT) in the binding pocket. These three residues dictate the binding orientation of dopamine in the binding pocket, as the aromatic ring of dopamine tends to take an orientation with both the para- and meta-hydroxyl groups being close to polar residues and away from nonpolar residues of the protein. The flipped binding orientations of dopamine in hDAT and dDAT clearly demonstrate a generally valuable insight concerning how the species difference could drastically affect the protein-ligand binding modes, demonstrating that the species difference, which is a factor rarely considered in early drug design stage, must be accounted for throughout the ligand/drug design and discovery processes in general.
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Affiliation(s)
- Yaxia Yuan
- Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, 715 Sumter Street, Columbia, South Carolina 29208, United States
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
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26
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Chen X, Deng J, Cui W, Hou S, Zhang J, Zheng X, Ding X, Wei H, Zhou Z, Kim K, Zhan CG, Zheng F. Development of Fc-Fused Cocaine Hydrolase for Cocaine Addiction Treatment: Catalytic and Pharmacokinetic Properties. AAPS JOURNAL 2018; 20:53. [PMID: 29556863 DOI: 10.1208/s12248-018-0214-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 02/27/2018] [Indexed: 11/30/2022]
Abstract
Cocaine abuse is a worldwide public health and social problem without a US Food and Drug Administration (FDA)-approved medication. Accelerating cocaine metabolism that produces biologically inactive metabolites by administration of an efficient cocaine hydrolase (CocH) has been recognized as a promising strategy for cocaine abuse treatment. However, the therapeutic effects of CocH are limited by its short biological half-life (e.g., 8 h or shorter in rats). In this study, we designed and prepared a set of Fc-fusion proteins constructed by fusing Fc(M3) with CocH3 at the N-terminus of CocH3. A linker between the two protein domains was optimized to improve both the biological half-life and catalytic activity against cocaine. It has been concluded that Fc(M3)-G6S-CocH3 not only has fully retained the catalytic efficiency of CocH3 against cocaine but also has the longest biological half-life (e.g., ∼ 136 h in rats) among all of the long-acting CocHs identified so far. A single dose (0.2 mg/kg, IV) of Fc(M3)-G6S-CocH3 was able to significantly attenuate 15 mg/kg cocaine-induced hyperactivity for at least 11 days (268 h) after the Fc(M3)-G6S-CocH3 administration.
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Affiliation(s)
- Xiabin Chen
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Jing Deng
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Wenpeng Cui
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Shurong Hou
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Jinling Zhang
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Xirong Zheng
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Xin Ding
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Huimei Wei
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Ziyuan Zhou
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Kyungbo Kim
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical Center (MMBC) and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
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27
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Elrashedy AAE. HIV-Associated Neurocognitive Disorder. BIG DATA ANALYTICS IN HIV/AIDS RESEARCH 2018:171-205. [DOI: 10.4018/978-1-5225-3203-3.ch008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
In the last two decades, several advancement studies have increased the care of HIV-infected individuals. Specifically, the development for preparation of combination antiretroviral therapy has resulted in a dramatic decline in the rate of deaths from AIDS. The term “HIV-associated neurocognitive disorder” (HAND) has been used to distinguish the spectrum of neurocognitive dysfunction associated with HIV infection. HIV can pass to the CNS during the early stages of infection and last in the CNS. CNS inflammation and infection lead to the development of HAND. The brain can serve as a sanctuary for ongoing HIV replication, even when the systemic viral suppression has been achieved. HAND can remain in patients treated with combination antiretroviral therapy, and its effect on survival, quality of life, and everyday functioning make it a significant unresolved problem. This chapter discusses details of the computational modeling studies on mechanisms and structures of human dopamine transporter (hDAT) and its interaction with HIV-1 trans activator of transcription (Tat).
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28
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Abstract
HIV-associated neurocognitive disorder (HAND) remains highly prevalent in HIV infected individuals and represents a special group of neuropathological disorders, which are associated with HIV-1 viral proteins, such as transactivator of transcription (Tat) protein. Cocaine abuse increases the incidence of HAND and exacerbates its severity by enhancing viral replication. Perturbation of dopaminergic transmission has been implicated as a risk factor of HAND. The presynaptic dopamine (DA) transporter (DAT) is essential for DA homeostasis and dopaminergic modulation of the brain function including cognition. Tat and cocaine synergistically elevate synaptic DA levels by acting directly on human DAT (hDAT), ultimately leading to dysregulation of DA transmission. Through integrated computational modeling and experimental validation, key residues have been identified in hDAT that play a critical role in Tat-induced inhibition of DAT and induce transporter conformational transitions. This review presents current information regarding neurological changes in DAT-mediated dopaminergic system associated with HIV infection, DAT-mediated adaptive responses to Tat as well as allosteric modulatory effects of novel compounds on hDAT. Understanding the molecular mechanisms by which Tat induces DAT-mediated dysregulation of DA system is of great clinical interest for identifying new targets for an early therapeutic intervention for HAND.
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29
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Gaskill PJ, Miller DR, Gamble-George J, Yano H, Khoshbouei H. HIV, Tat and dopamine transmission. Neurobiol Dis 2017; 105:51-73. [PMID: 28457951 PMCID: PMC5541386 DOI: 10.1016/j.nbd.2017.04.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/04/2017] [Accepted: 04/16/2017] [Indexed: 01/02/2023] Open
Abstract
Human Immunodeficiency Virus (HIV) is a progressive infection that targets the immune system, affecting more than 37 million people around the world. While combinatorial antiretroviral therapy (cART) has lowered mortality rates and improved quality of life in infected individuals, the prevalence of HIV associated neurocognitive disorders is increasing and HIV associated cognitive decline remains prevalent. Recent research has suggested that HIV accessory proteins may be involved in this decline, and several studies have indicated that the HIV protein transactivator of transcription (Tat) can disrupt normal neuronal and glial function. Specifically, data indicate that Tat may directly impact dopaminergic neurotransmission, by modulating the function of the dopamine transporter and specifically damaging dopamine-rich regions of the CNS. HIV infection of the CNS has long been associated with dopaminergic dysfunction, but the mechanisms remain undefined. The specific effect(s) of Tat on dopaminergic neurotransmission may be, at least partially, a mechanism by which HIV infection directly or indirectly induces dopaminergic dysfunction. Therefore, precisely defining the specific effects of Tat on the dopaminergic system will help to elucidate the mechanisms by which HIV infection of the CNS induces neuropsychiatric, neurocognitive and neurological disorders that involve dopaminergic neurotransmission. Further, this will provide a discussion of the experiments needed to further these investigations, and may help to identify or develop new therapeutic approaches for the prevention or treatment of these disorders in HIV-infected individuals.
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Affiliation(s)
- Peter J Gaskill
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, United States.
| | - Douglas R Miller
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, United States
| | - Joyonna Gamble-George
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, United States
| | - Hideaki Yano
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, United States
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, United States.
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30
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Sun WL, Quizon PM, Yuan Y, Zhang W, Ananthan S, Zhan CG, Zhu J. Allosteric modulatory effects of SRI-20041 and SRI-30827 on cocaine and HIV-1 Tat protein binding to human dopamine transporter. Sci Rep 2017. [PMID: 28623359 PMCID: PMC5473888 DOI: 10.1038/s41598-017-03771-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Dopamine transporter (DAT) is the target of cocaine and HIV-1 transactivator of transcription (Tat) protein. Identifying allosteric modulatory molecules with potential attenuation of cocaine and Tat binding to DAT are of great scientific and clinical interest. We demonstrated that tyrosine 470 and 88 act as functional recognition residues in human DAT (hDAT) for Tat-induced inhibition of DA transport and transporter conformational transitions. Here we investigated the allosteric modulatory effects of two allosteric ligands, SRI-20041 and SRI-30827 on cocaine binding on wild type (WT) hDAT, Y470 H and Y88 F mutants. Effect of SRI-30827 on Tat-induced inhibition of [3H]WIN35,428 binding was also determined. Compared to a competitive DAT inhibitor indatraline, both SRI-compounds displayed a similar decrease (30%) in IC50 for inhibition of [3H]DA uptake by cocaine in WT hDAT. The addition of SRI-20041 or SRI-30827 following cocaine slowed the dissociation rate of [3H]WIN35,428 binding in WT hDAT relative to cocaine alone. Moreover, Y470H and Y88F hDAT potentiate the inhibitory effect of cocaine on DA uptake and attenuate the effects of SRI-compounds on cocaine-mediated dissociation rate. SRI-30827 attenuated Tat-induced inhibition of [3H]WIN35,428 binding. These observations demonstrate that tyrosine 470 and 88 are critical for allosteric modulatory effects of SRI-compounds on the interaction of cocaine with hDAT.
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Affiliation(s)
- Wei-Lun Sun
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA
| | - Pamela M Quizon
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA
| | - Yaxia Yuan
- Molecular Modeling and Biopharmaceutical Center, University of Kentucky, Lexington, KY, USA.,Center for Pharmaceutical Research and Innovation, University of Kentucky, Lexington, KY, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA
| | - Wei Zhang
- Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, AL, USA
| | - Subramaniam Ananthan
- Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, AL, USA
| | - Chang-Guo Zhan
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA.,Center for Pharmaceutical Research and Innovation, University of Kentucky, Lexington, KY, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA
| | - Jun Zhu
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA.
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31
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Ronsard L, Ganguli N, Singh VK, Mohankumar K, Rai T, Sridharan S, Pajaniradje S, Kumar B, Rai D, Chaudhuri S, Coumar MS, Ramachandran VG, Banerjea AC. Impact of Genetic Variations in HIV-1 Tat on LTR-Mediated Transcription via TAR RNA Interaction. Front Microbiol 2017; 8:706. [PMID: 28484443 PMCID: PMC5399533 DOI: 10.3389/fmicb.2017.00706] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/05/2017] [Indexed: 01/10/2023] Open
Abstract
HIV-1 evades host defense through mutations and recombination events, generating numerous variants in an infected patient. These variants with an undiminished virulence can multiply rapidly in order to progress to AIDS. One of the targets to intervene in HIV-1 replication is the trans-activator of transcription (Tat), a major regulatory protein that transactivates the long terminal repeat promoter through its interaction with trans-activation response (TAR) RNA. In this study, HIV-1 infected patients (n = 120) from North India revealed Ser46Phe (20%) and Ser61Arg (2%) mutations in the Tat variants with a strong interaction toward TAR leading to enhanced transactivation activities. Molecular dynamics simulation data verified that the variants with this mutation had a higher binding affinity for TAR than both the wild-type Tat and other variants that lacked Ser46Phe and Ser61Arg. Other mutations in Tat conferred varying affinities for TAR interaction leading to differential transactivation abilities. This is the first report from North India with a clinical validation of CD4 counts to demonstrate the influence of Tat genetic variations affecting the stability of Tat and its interaction with TAR. This study highlights the co-evolution pattern of Tat and predominant nucleotides for Tat activity, facilitating the identification of genetic determinants for the attenuation of viral gene expression.
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Affiliation(s)
- Larance Ronsard
- Laboratory of Virology, National Institute of ImmunologyDelhi, India.,Department of Microbiology, University College of Medical Sciences and Guru Teg Bahadur HospitalDelhi, India
| | - Nilanjana Ganguli
- Laboratory of Virology, National Institute of ImmunologyDelhi, India
| | - Vivek K Singh
- Centre for Bioinformatics, School of Life Sciences, Pondicherry UniversityPondicherry, India
| | - Kumaravel Mohankumar
- Department of Biochemistry and Molecular Biology, Pondicherry UniversityPondicherry, India.,Department of Veterinary Physiology and Pharmacology, Texas A&M University, College StationTX, USA
| | - Tripti Rai
- Department of Gastroenterology and Human Nutrition, All India Institute of Medical SciencesDelhi, India
| | - Subhashree Sridharan
- Department of Biochemistry and Molecular Biology, Pondicherry UniversityPondicherry, India.,Department of Symptom Research, The University of Texas MD Anderson Cancer Center, HoustonTX, USA
| | - Sankar Pajaniradje
- Department of Biochemistry and Molecular Biology, Pondicherry UniversityPondicherry, India
| | - Binod Kumar
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, ChicagoIL, USA
| | - Devesh Rai
- Department of Microbiology, All India Institute of Medical SciencesDelhi, India
| | - Suhnrita Chaudhuri
- Department of Neurological Surgery, Northwestern University, ChicagoIL, USA
| | - Mohane S Coumar
- Centre for Bioinformatics, School of Life Sciences, Pondicherry UniversityPondicherry, India
| | | | - Akhil C Banerjea
- Laboratory of Virology, National Institute of ImmunologyDelhi, India
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Kacprzak V, Patel NA, Riley E, Yu L, Yeh JRJ, Zhdanova IV. Dopaminergic control of anxiety in young and aged zebrafish. Pharmacol Biochem Behav 2017; 157:1-8. [PMID: 28408289 DOI: 10.1016/j.pbb.2017.01.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 01/26/2023]
Abstract
Changes in the expression of the dopamine transporter (DAT), or the sensitivity of dopamine receptors, are associated with aging and substance abuse and may underlie some of the symptoms common to both conditions. In this study, we explored the role of the dopaminergic system in the anxiogenic effects of aging and acute cocaine exposure by comparing the behavioral phenotypes of wild type (WT) and DAT knockout zebrafish (DAT-KO) of different ages. To determine the involvement of specific dopamine receptors in anxiety states, antagonists to D1 (SCH23390) and D2/D3 (sulpiride) were employed. We established that DAT-KO results in a chronic anxiety-like state, seen as an increase in bottom-dwelling and thigmotaxis. Similar effects were produced by aging and acute cocaine administration, both leading to reduction in DAT mRNA abundance (qPCR). Inhibition of D1 activity counteracted the anxiety-like effects associated with DAT deficit, independent of its origin. Inhibition of D2/D3 receptors reduced anxiety in young DAT-KO, and enhanced the anxiogenic effects of cocaine in WT, but did not affect aged WT or DAT-KO fish. These findings provide new evidence that the dopaminergic system plays a critical role in anxiety-like states, and suggest that adult zebrafish provide a sensitive diurnal vertebrate model for elucidating the molecular mechanisms of anxiety and a platform for anxiolytic drug screens.
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Affiliation(s)
- Victoria Kacprzak
- Boston University School of Medicine, Lab of Sleep and Circadian Physiology, R-911, 72 E. Concord St., Boston, MA 02118, United States.
| | - Neil A Patel
- Boston University School of Medicine, Lab of Sleep and Circadian Physiology, R-911, 72 E. Concord St., Boston, MA 02118, United States.
| | - Elizabeth Riley
- Boston University School of Medicine, Lab of Sleep and Circadian Physiology, R-911, 72 E. Concord St., Boston, MA 02118, United States.
| | - Lili Yu
- Boston University School of Medicine, Lab of Sleep and Circadian Physiology, R-911, 72 E. Concord St., Boston, MA 02118, United States.
| | - Jing-Ruey J Yeh
- Massachusetts General Hospital, Cardiovascular Research Center, 149 13th St., 4.217, Charlestown, MA 02129, United States.
| | - Irina V Zhdanova
- Boston University School of Medicine, Lab of Sleep and Circadian Physiology, R-911, 72 E. Concord St., Boston, MA 02118, United States.
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Molecular mechanism: the human dopamine transporter histidine 547 regulates basal and HIV-1 Tat protein-inhibited dopamine transport. Sci Rep 2016; 6:39048. [PMID: 27966610 PMCID: PMC5155291 DOI: 10.1038/srep39048] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 11/17/2016] [Indexed: 12/15/2022] Open
Abstract
Abnormal dopaminergic transmission has been implicated as a risk determinant of HIV-1-associated neurocognitive disorders. HIV-1 Tat protein increases synaptic dopamine (DA) levels by directly inhibiting DA transporter (DAT) activity, ultimately leading to dopaminergic neuron damage. Through integrated computational modeling prediction and experimental validation, we identified that histidine547 on human DAT (hDAT) is critical for regulation of basal DA uptake and Tat-induced inhibition of DA transport. Compared to wild type hDAT (WT hDAT), mutation of histidine547 (H547A) displayed a 196% increase in DA uptake. Other substitutions of histidine547 showed that DA uptake was not altered in H547R but decreased by 99% in H547P and 60% in H547D, respectively. These mutants did not alter DAT surface expression or surface DAT binding sites. H547 mutants attenuated Tat-induced inhibition of DA transport observed in WT hDAT. H547A displays a differential sensitivity to PMA- or BIM-induced activation or inhibition of DAT function relative to WT hDAT, indicating a change in basal PKC activity in H547A. These findings demonstrate that histidine547 on hDAT plays a crucial role in stabilizing basal DA transport and Tat-DAT interaction. This study provides mechanistic insights into identifying targets on DAT for Tat binding and improving DAT-mediated dysfunction of DA transmission.
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Yuan Y, Huang X, Zhu J, Zhan CG. Computational modeling of human dopamine transporter structures, mechanism and its interaction with HIV-1 transactivator of transcription. Future Med Chem 2016; 8:2077-2089. [PMID: 27739323 PMCID: PMC6113701 DOI: 10.4155/fmc-2016-0138] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/20/2016] [Indexed: 11/17/2022] Open
Abstract
This is a brief review of computational modeling studies on the detailed structures and mechanism of human dopamine transporter (hDAT), as well as its interaction with HIV-1 transactivator of transcription (Tat). Extensive molecular modeling, docking and dynamics simulations have resulted in reasonable structural models of hDAT in three typical conformational states, its dopamine uptake mechanism and its interaction with Tat. The obtained hDAT models in different conformational states and their complexes with dopamine and Tat have provided novel structural and mechanistic insights concerning how hDAT uptakes dopamine and how Tat affects the dopamine uptake by hDAT. The computational insights, that are consistent with available experimental data, should be valuable for future rational design of novel therapeutic strategies for treatment of HIV-associated neurocognitive disorders.
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Affiliation(s)
- Yaxia Yuan
- Molecular Modeling & Biopharmaceutical Center, Center for Pharmaceutical Research & Innovation, and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Xiaoqin Huang
- Molecular Modeling & Biopharmaceutical Center, Center for Pharmaceutical Research & Innovation, and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Jun Zhu
- Department of Drug Discovery & Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA
| | - Chang-Guo Zhan
- Molecular Modeling & Biopharmaceutical Center, Center for Pharmaceutical Research & Innovation, and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
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Role of Histidine 547 of Human Dopamine Transporter in Molecular Interaction with HIV-1 Tat and Dopamine Uptake. Sci Rep 2016; 6:27314. [PMID: 27250920 PMCID: PMC4890318 DOI: 10.1038/srep27314] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 05/13/2016] [Indexed: 12/16/2022] Open
Abstract
HIV-1 Tat plays an important role in HIV-associated neurocognitive disorders (HAND) by disrupting neurotransmission including dopamine uptake by human dopamine transporter (hDAT). Previous studies have demonstrated that HIV-1 Tat directly binds to hDAT and some amino-acid mutations that attenuate the hDAT-Tat binding also significantly decreased dopamine uptake activity of hDAT. This combined computational-experimental study demonstrates that histidine-547 (H547) of hDAT plays a crucial role in the hDAT-Tat binding and dopamine uptake by hDAT, and that the H547A mutation can not only considerably attenuate Tat-induced inhibition of dopamine uptake, but also significantly increase the Vmax of hDAT for dopamine uptake. The finding of such an unusual hDAT mutant capable of both increasing the Vmax of hDAT for dopamine uptake and disrupting the hDAT-Tat binding may provide an exciting knowledge basis for development of novel concepts for therapeutic treatment of the HAND.
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HIV-1 transgenic rats display an increase in [(3)H]dopamine uptake in the prefrontal cortex and striatum. J Neurovirol 2015; 22:282-92. [PMID: 26501780 DOI: 10.1007/s13365-015-0391-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 09/07/2015] [Accepted: 10/02/2015] [Indexed: 10/22/2022]
Abstract
HIV viral proteins within the central nervous system are associated with the development of neurocognitive impairments in HIV-infected individuals. Dopamine transporter (DAT)-mediated dopamine transport is critical for normal dopamine homeostasis. Abnormal dopaminergic transmission has been implicated as a risk determinant of HIV-induced neurocognitive impairments. Our published work has demonstrated that transactivator of transcription (Tat)-induced inhibition of DAT is mediated by allosteric binding site(s) on DAT, not the interaction with the dopamine uptake site. The present study investigated whether impaired DAT function induced by Tat exposure in vitro can be documented in HIV-1 transgenic (HIV-1Tg) rats. We assessed kinetic analyses of [(3)H]dopamine uptake into prefrontal and striatal synaptosomes of HIV-1Tg and Fisher 344 rats. Compared with Fisher 344 rats, the capacity of dopamine transport in the prefrontal cortex (PFC) and striatum of HIV-1Tg rats was increased by 34 and 32 %, respectively. Assessment of surface biotinylation indicated that DAT expression in the plasma membrane was reduced in PFC and enhanced in striatum, respectively, of HIV-1Tg rats. While the maximal binding sites (B max) of [(3)H]WIN 35,428 was decreased in striatum of HIV-1Tg rats, an increase in DAT turnover proportion was found, relative to Fisher 344 rats. Together, these findings suggest that neuroadaptive changes in DAT function are evidenced in the HIV-1Tg rats, perhaps compensating for viral-protein-induced abnormal dopaminergic transmission. Thus, our study provides novel insights into understanding mechanism underlying neurocognitive impairment evident in neuroAIDS.
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Dahal S, Chitti SVP, Nair MPN, Saxena SK. Interactive effects of cocaine on HIV infection: implication in HIV-associated neurocognitive disorder and neuroAIDS. Front Microbiol 2015; 6:931. [PMID: 26441868 PMCID: PMC4562305 DOI: 10.3389/fmicb.2015.00931] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 08/24/2015] [Indexed: 11/13/2022] Open
Abstract
Substantial epidemiological studies suggest that not only, being one of the reasons for the transmission of the human immunodeficiency virus (HIV), but drug abuse also serves its role in determining the disease progression and severity among the HIV infected population. This article focuses on the drug cocaine, and its role in facilitating entry of HIV into the CNS and mechanisms of development of neurologic complications in infected individuals. Cocaine is a powerfully addictive central nervous system stimulating drug, which increases the level of neurotransmitter dopamine (DA) in the brain, by blocking the dopamine transporters (DAT) which is critical for DA homeostasis and neurocognitive function. Tat protein of HIV acts as an allosteric modulator of DAT, where as cocaine acts as reuptake inhibitor. When macrophages in the CNS are exposed to DA, their number increases. These macrophages release inflammatory mediators and neurotoxins, causing chronic neuroinflammation. Cocaine abuse during HIV infection enhances the production of platelet monocyte complexes (PMCs), which may cross transendothelial barrier, and result in HIV-associated neurocognitive disorder (HAND). HAND is characterized by neuroinflammation, including astrogliosis, multinucleated giant cells, and neuronal apoptosis that is linked to progressive virus infection and immune deterioration. Cocaine and viral proteins are capable of eliciting signaling transduction pathways in neurons, involving in mitochondrial membrane potential loss, oxidative stress, activation of JNK, p38, and ERK/MAPK pathways, and results in downstream activation of NF-κB that leads to HAND. Tat-induced inflammation provokes permeability of the blood brain barrier (BBB) in the platelet dependent manner, which can potentially be the reason for progression to HAND during HIV infection. A better understanding on the role of cocaine in HIV infection can give a clue in developing novel therapeutic strategies against HIV-1 infection in cocaine using HIV infected population.
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Affiliation(s)
- Santosh Dahal
- CSIR-Centre for Cellular and Molecular Biology , Hyderabad, India
| | - Sai V P Chitti
- CSIR-Centre for Cellular and Molecular Biology , Hyderabad, India
| | - Madhavan P N Nair
- College of Medicine, Florida International University , Miami, FL, USA
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Mutations at tyrosine 88, lysine 92 and tyrosine 470 of human dopamine transporter result in an attenuation of HIV-1 Tat-induced inhibition of dopamine transport. J Neuroimmune Pharmacol 2015; 10:122-35. [PMID: 25604666 DOI: 10.1007/s11481-015-9583-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 01/12/2015] [Indexed: 12/13/2022]
Abstract
HIV-1 transactivator of transcription (Tat) protein disrupts the dopamine (DA) neurotransmission by inhibiting DA transporter (DAT) function, leading to increased neurocognitive impairment in HIV-1 infected individuals. Through integrated computational modeling and pharmacological studies, we have demonstrated that mutation of tyrosine470 (Y470H) of human DAT (hDAT) attenuates Tat-induced inhibition of DA uptake by changing the transporter conformational transitions. The present study examined the functional influences of other substitutions at tyrosine470 (Y470F and Y470A) and tyrosine88 (Y88F) and lysine92 (K92M), two other relevant residues for Tat binding to hDAT, in Tat-induced inhibitory effects on DA transport. Y88F, K92M and Y470A attenuated Tat-induced inhibition of DA transport, implicating the functional relevance of these residues for Tat binding to hDAT. Compared to wild type hDAT, Y470A and K92M but not Y88F reduced the maximal velocity of [(3)H]DA uptake without changes in the Km. Y88F and K92M enhanced IC50 values for DA inhibition of [(3)H]DA uptake and [(3)H]WIN35,428 binding but decreased IC50 for cocaine and GBR12909 inhibition of [(3)H]DA uptake, suggesting that these residues are critical for substrate and these inhibitors. Y470F, Y470A, Y88F and K92M attenuated zinc-induced increase of [(3)H]WIN35,428 binding. Moreover, only Y470A and K92M enhanced DA efflux relative to wild type hDAT, suggesting mutations of these residues differentially modulate transporter conformational transitions. These results demonstrate Tyr88 and Lys92 along with Tyr470 as functional recognition residues in hDAT for Tat-induced inhibition of DA transport and provide mechanistic insights into identifying target residues on the DAT for Tat binding.
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