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Asia LK, Van Vuren EJ, Lindeque Z, Williams ME. A pilot investigation of the association between HIV-1 Vpr amino acid sequence diversity and the tryptophan-kynurenine pathway as a potential mechanism for neurocognitive impairment. Virol J 2024; 21:47. [PMID: 38395987 PMCID: PMC10893664 DOI: 10.1186/s12985-024-02313-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
HIV infection compromises both the peripheral and central immune systems due to its pathogenic and neuropathogenic features. The mechanisms driving HIV-1 pathogenesis and neuropathogenesis involve a series of events, including metabolic dysregulation. Furthermore, HIV-subtype-specific variations, particularly alterations in the amino acid sequences of key viral proteins, are known to influence the severity of clinical outcomes in people living with HIV. However, the impact of amino acid sequence variations in specific viral proteins, such as Viral protein R (Vpr), on metabolites within the Tryptophan (Trp)-kynurenine (Kyn) pathway in people living with HIV remains unclear. Our research aimed to explore the relationship between variations in the Vpr amino acid sequence (specifically at positions 22, 41, 45, and 55, as these have been previously linked to neurocognitive function) and peripheral Trp-Kyn metabolites. Additionally, we sought to clarify the systems biology of Vpr sequence variation by examining the link between Trp-Kyn metabolism and peripheral inflammation, as a neuropathogenic mechanism. In this preliminary study, we analyzed a unique cohort of thirty-two (n = 32) South African cART naïve people living with HIV. We employed Sanger sequencing to ascertain blood-derived Vpr amino acid sequence variations and a targeted LC-MS/MS metabolomics platform to assess Trp-Kyn metabolites, such as Trp, Kyn, kynurenic acid (KA), and quinolinic acid (QUIN). Particle-enhanced turbidimetric assay and Enzyme-linked immunosorbent assays were used to measure immune markers, hsCRP, IL-6, suPAR, NGAL and sCD163. After applying Bonferroni corrections (p =.05/3) and adjusting for covariates (age and sex), only the Vpr G41 and A55 groups was nearing significance for higher levels of QUIN compared to the Vpr S41 and T55 groups, respectively (all p =.023). Multiple regression results revealed that Vpr amino acid variations at position 41 (adj R2 = 0.049, β = 0.505; p =.023), and 55 (adj R2 = 0.126, β = 0.444; p =.023) displayed significant associations with QUIN after adjusting for age and sex. Lastly, the higher QUIN levels observed in the Vpr G41 group were found to be correlated with suPAR (r =.588, p =.005). These results collectively underscore the importance of specific Vpr amino acid substitutions in influencing QUIN and inflammation (specifically suPAR levels), potentially contributing to our understanding of their roles in the pathogenesis and neuropathogenesis of HIV-1.
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Affiliation(s)
| | - Esmé Jansen Van Vuren
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
- South African Medical Research Council, Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Zander Lindeque
- Human Metabolomics, North-West University, Potchefstroom, South Africa
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Campbell GR, Rawat P, To RK, Spector SA. HIV-1 Tat Upregulates TREM1 Expression in Human Microglia. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:429-442. [PMID: 37326481 PMCID: PMC10352590 DOI: 10.4049/jimmunol.2300152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/30/2023] [Indexed: 06/17/2023]
Abstract
Because microglia are a reservoir for HIV and are resistant to the cytopathic effects of HIV infection, they are a roadblock for any HIV cure strategy. We have previously identified that triggering receptor expressed on myeloid cells 1 (TREM1) plays a key role in human macrophage resistance to HIV-mediated cytopathogenesis. In this article, we show that HIV-infected human microglia express increased levels of TREM1 and are resistant to HIV-induced apoptosis. Moreover, upon genetic inhibition of TREM1, HIV-infected microglia undergo cell death in the absence of increased viral or proinflammatory cytokine expression or the targeting of uninfected cells. We also show that the expression of TREM1 is mediated by HIV Tat through a TLR4, TICAM1, PG-endoperoxide synthase 2, PGE synthase, and PGE2-dependent manner. These findings highlight the potential of TREM1 as a therapeutic target to eradicate HIV-infected microglia without inducing a proinflammatory response.
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Affiliation(s)
- Grant R. Campbell
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD
| | - Pratima Rawat
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA
| | - Rachel K. To
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA
| | - Stephen A. Spector
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA
- Rady Children’s Hospital, San Diego, CA
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3
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Haddad A, Voth B, Brooks J, Swang M, Carryl H, Algarzae N, Taylor S, Parker C, Van Rompay KKA, De Paris K, Burke MW. Reduced neuronal population in the dorsolateral prefrontal cortex in infant macaques infected with simian immunodeficiency virus (SIV). J Neurovirol 2021; 27:923-935. [PMID: 34554407 PMCID: PMC8901521 DOI: 10.1007/s13365-021-01019-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/11/2021] [Accepted: 08/26/2021] [Indexed: 11/29/2022]
Abstract
Pediatric HIV infection remains a global health crisis with an estimated 150,000 new mother-to-child (MTCT) infections each year. Antiretroviral therapy (ART) has improved childhood survival, but only an estimated 53% of children worldwide have access to treatment. Adding to the health crisis is the neurological impact of HIV on the developing brain, in particular cognitive and executive function, which persists even when ART is available. Imaging studies suggest structural, connectivity, and functional alterations in perinatally HIV-infected youth. However, the paucity of histological data limits our ability to identify specific cortical regions that may underlie the clinical manifestations. Utilizing the pediatric simian immunodeficiency virus (SIV) infection model in infant macaques, we have previously shown that early-life SIV infection depletes the neuronal population in the hippocampus. Here, we expand on these previous studies to investigate the dorsolateral prefrontal cortex (dlPFC). A total of 11 ART-naïve infant rhesus macaques (Macaca mulatta) from previous studies were retrospectively analyzed. Infant macaques were either intravenously (IV) inoculated with highly virulent SIVmac251 at ~1 week of age and monitored for 6-10 weeks or orally challenged with SIVmac251 from week 9 of age onwards with a monitoring period of 10-23 weeks post-infection (19-34 weeks of age), and SIV-uninfected controls were euthanized at 16-17 weeks of age. Both SIV-infected groups show a significant loss of neurons along with evidence of ongoing neuronal death. Oral- and IV-infected animals showed a similar neuronal loss which was negatively correlated to chronic viremia levels as assessed by an area under the curve (AUC) analysis. The loss of dlPFC neurons may contribute to the rapid neurocognitive decline associated with pediatric HIV infection.
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Affiliation(s)
- Alexandra Haddad
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA
| | - Brittany Voth
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA
| | - Janiya Brooks
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA
| | - Melanie Swang
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA
| | - Heather Carryl
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA
| | - Norah Algarzae
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA
- King Saudi University, Riyadh, Riyadh, Kingdom of Saudi Arabia
| | - Shane Taylor
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA
| | - Camryn Parker
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA
| | - Koen K A Van Rompay
- California National Primate Research Center, University of California Davis, Davis, CA, 95616, USA
| | - Kristina De Paris
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Mark W Burke
- Department of Physiology and Biophysics, Howard University, Washington, DC, 20059, USA.
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4
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Fitting S, McRae M, Hauser KF. Opioid and neuroHIV Comorbidity - Current and Future Perspectives. J Neuroimmune Pharmacol 2020; 15:584-627. [PMID: 32876803 PMCID: PMC7463108 DOI: 10.1007/s11481-020-09941-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022]
Abstract
With the current national opioid crisis, it is critical to examine the mechanisms underlying pathophysiologic interactions between human immunodeficiency virus (HIV) and opioids in the central nervous system (CNS). Recent advances in experimental models, methodology, and our understanding of disease processes at the molecular and cellular levels reveal opioid-HIV interactions with increasing clarity. However, despite the substantial new insight, the unique impact of opioids on the severity, progression, and prognosis of neuroHIV and HIV-associated neurocognitive disorders (HAND) are not fully understood. In this review, we explore, in detail, what is currently known about mechanisms underlying opioid interactions with HIV, with emphasis on individual HIV-1-expressed gene products at the molecular, cellular and systems levels. Furthermore, we review preclinical and clinical studies with a focus on key considerations when addressing questions of whether opioid-HIV interactive pathogenesis results in unique structural or functional deficits not seen with either disease alone. These considerations include, understanding the combined consequences of HIV-1 genetic variants, host variants, and μ-opioid receptor (MOR) and HIV chemokine co-receptor interactions on the comorbidity. Lastly, we present topics that need to be considered in the future to better understand the unique contributions of opioids to the pathophysiology of neuroHIV. Graphical Abstract Blood-brain barrier and the neurovascular unit. With HIV and opiate co-exposure (represented below the dotted line), there is breakdown of tight junction proteins and increased leakage of paracellular compounds into the brain. Despite this, opiate exposure selectively increases the expression of some efflux transporters, thereby restricting brain penetration of specific drugs.
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Affiliation(s)
- Sylvia Fitting
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3270, USA
| | - MaryPeace McRae
- Department of Pharmacotherapy and Outcomes Science, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Kurt F Hauser
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1217 East Marshall Street, Richmond, VA, 23298-0613, USA.
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University, Richmond, VA, 23298-0709, USA.
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University, 203 East Cary Street, Richmond, VA, 23298-0059, USA.
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Campbell GR, To RK, Zhang G, Spector SA. SMAC mimetics induce autophagy-dependent apoptosis of HIV-1-infected macrophages. Cell Death Dis 2020; 11:590. [PMID: 32719312 PMCID: PMC7385130 DOI: 10.1038/s41419-020-02761-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/29/2020] [Accepted: 07/06/2020] [Indexed: 12/18/2022]
Abstract
Human immunodeficiency type 1 (HIV)-infected macrophages (HIV-Mφ) are a reservoir for latent HIV infection and a barrier to HIV eradication. In contrast to CD4+ T cells, HIV-Mφ are resistant to the cytopathic effects of acute HIV infection and have increased expression of cell survival factors, including X-linked inhibitor of apoptosis (XIAP), baculoviral IAP repeat containing (BIRC) 2/cIAP1, beclin-1, BCL2, BCL-xl, triggering receptor expressed on myeloid cells 1, mitofusin (MFN) 1, and MFN2. DIABLO/SMAC mimetics are therapeutic agents that affect cancer cell survival and induce cell death. We found that DIABLO/SMAC mimetics (LCL-161, AT-406 (also known as SM-406 or Debio 1143), and birinapant) selectively kill HIV-Mφ without increasing bystander cell death. DIABLO/SMAC mimetic treatment of HIV-Mφ-induced XIAP and BIRC2 degradation, leading to the induction of autophagy and the formation of a death-inducing signaling complex on phagophore membranes that includes both pro-apoptotic or necroptotic (FADD, receptor-interacting protein kinase (RIPK) 1, RIPK3, caspase 8, and MLKL) and autophagy (ATG5, ATG7, and SQSTM1) proteins. Genetic or pharmacologic inhibition of early stages of autophagy, but not late stages of autophagy, ablated this interaction and inhibited apoptosis. Furthermore, DIABLO/SMAC mimetic-mediated apoptosis of HIV-Mφ is dependent upon tumor necrosis factor signaling. Our findings thus demonstrate that DIABLO/SMAC mimetics selectively induce autophagy-dependent apoptosis in HIV-Mφ.
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Affiliation(s)
- Grant R Campbell
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA, USA.
| | - Rachel K To
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Gang Zhang
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
- Gladstone Center for HIV Cure Research, Gladstone Institute of Virology and Immunology, San Francisco, CA, USA
| | - Stephen A Spector
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA, USA.
- Rady Children's Hospital, San Diego, CA, USA.
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Santerre M, Wang Y, Arjona S, Allen C, Sawaya BE. Differential Contribution of HIV-1 Subtypes B and C to Neurological Disorders: Mechanisms and Possible Treatments. AIDS Rev 2019; 21:76-83. [PMID: 31332398 DOI: 10.24875/aidsrev.19000051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With the introduction of combinatory antiretroviral therapy, patients infected with human immunodeficiency virus type 1 (HIV-1) can live much longer than before. However, the identification of HIV-associated neurocognitive disorder (HAND), especially HIV-associated dementia in 15-20% of patients infected with HIV-1, indicates additional complexity. These disorders turn out to be subtype dependent. Recently, many studies are ongoing trying to understand how the virus induces neuronal injury which could lead to neurological dysfunction. Most of these studies are focusing on the HIV-1 release of proteins such as Tat. However, the exact role of these proteins and their involvement in neuronal degeneration remains unidentified; this is especially true since viral proteins from different HIV-1 subtypes differ in their ability to cause neuronal damage. This review describes the role of different HIV-1 subtypes, identifies probable pathways involved in neuronal damage, the contribution of different HIV-1 subtypes to the progression of HAND, and potential treatments for HAND.
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Affiliation(s)
- Maryline Santerre
- Molecular Studies of Neurodegenerative Diseases Lab, FELS Institute for Cancer Research and Molecular Biology, Philadelphia, Pennsylvania, USA
| | - Ying Wang
- Molecular Studies of Neurodegenerative Diseases Lab, FELS Institute for Cancer Research and Molecular Biology, Philadelphia, Pennsylvania, USA
| | - Sterling Arjona
- Molecular Studies of Neurodegenerative Diseases Lab, FELS Institute for Cancer Research and Molecular Biology, Philadelphia, Pennsylvania, USA
| | - Charles Allen
- Molecular Studies of Neurodegenerative Diseases Lab, FELS Institute for Cancer Research and Molecular Biology, Philadelphia, Pennsylvania, USA
| | - Bassel E Sawaya
- Department of Neurology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
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TREM-1 Protects HIV-1-Infected Macrophages from Apoptosis through Maintenance of Mitochondrial Function. mBio 2019; 10:mBio.02638-19. [PMID: 31719184 PMCID: PMC6851287 DOI: 10.1128/mbio.02638-19] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The major challenge to human immunodeficiency virus (HIV) treatment is the development of strategies that lead to viral eradication. A roadblock to accomplishing this goal is the lack of an approach that would safely eliminate HIV from all resting/latent reservoirs, including macrophages. Macrophages are a key part of the innate immune system and are responsible for recognizing invading microbes and sending appropriate signals to other immune cells. Here, we found that HIV induces the upregulation of the protein TREM1 (triggering receptor expressed on myeloid cells 1), which signals an increase in the expression of antiapoptotic proteins, thus promoting survival of HIV-infected macrophages. Macrophages are a reservoir for latent human immunodeficiency type 1 (HIV) infection and a barrier to HIV eradication. In contrast to CD4+ T cells, macrophages are resistant to the cytopathic effects of acute HIV infection. Emerging data suggest a role for TREM1 (triggering receptor expressed on myeloid cells 1) in this resistance to HIV-mediated cytopathogenesis. Here, we show that upon HIV infection, macrophages increase the expression of BCL2, BCLXL, TREM1, mitofusin 1 (MFN1), and MFN2 and the translocation of BCL2L11 (BIM) to the mitochondria and decrease the expression of BCL2-associated agonist of cell death (BAD) and BAX while maintaining a 95% survival rate over 28 days. The HIV proteins Tat and gp120 and the GU-rich single-stranded RNA (ssRNA) (RNA40) from the HIV long terminal repeat region (and a natural Toll-like receptor 8 [TLR8] agonist) induced similar effects. TREM1 silencing in HIV-infected macrophages led to decreased expression of BCL2, BCLXL, MFN1, and MFN2 and increased expression of BAD and BAX. This correlated with a significant increase in apoptosis mediated by a disruption of the mitochondrial membrane potential (Δψm), leading to the release of cytochrome c and caspase 9 cleavage. Exposure of TREM1-silenced macrophages to Tat, gp120, or RNA40 similarly resulted in the disruption of Δψm, cytochrome c release, caspase 9 cleavage, and apoptosis. Thus, our findings identify a mechanism whereby HIV promotes macrophage survival through TREM1-dependent upregulation of BCL2 family proteins and mitofusins that inhibits BCL2L11-mediated disruption of Δψm and subsequent apoptosis. These findings indicate that TREM1 can be a useful target for elimination of the HIV reservoir in macrophages.
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Campbell GR, Bruckman RS, Chu YL, Trout RN, Spector SA. SMAC Mimetics Induce Autophagy-Dependent Apoptosis of HIV-1-Infected Resting Memory CD4+ T Cells. Cell Host Microbe 2018; 24:689-702.e7. [PMID: 30344003 PMCID: PMC6250054 DOI: 10.1016/j.chom.2018.09.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/15/2018] [Accepted: 09/11/2018] [Indexed: 12/18/2022]
Abstract
Long-lived resting memory CD4+ T cells (TCM) are a major reservoir of latent HIV infection. We hypothesized that latent HIV-TCM cells are maintained by aberrant expression of cell survival factors, including XIAP, BIRC2/cIAP1, and beclin-1. DIABLO/SMAC mimetics are therapeutic agents that compromise cell survival by hijacking host apoptotic machinery. We found that DIABLO/SMAC mimetics (birinapant, GDC-0152, and embelin) selectively kill HIV-TCM without increasing virus production or targeting uninfected TCM. Treatment of HIV-TCM with DIABLO/SMAC mimetics promoted XIAP and BIRC2 degradation, which triggered autophagy and the formation of a cell death complex consisting of pro-apoptotic (FADD, RIPK1, RIPK3, and caspase 8) and autophagy (ATG5, ATG7, and SQSTM1) proteins. Genetic or pharmacological inhibition of autophagy induction, but not autophagy-mediated degradation, abrogated this interaction and subsequent cell death. Our findings identify a mechanism whereby DIABLO/SMAC mimetics exploit autophagy and apoptotic machinery to selectively induce killing of HIV-TCM without viral reactivation while sparing uninfected cells.
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Affiliation(s)
- Grant R Campbell
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Rachel S Bruckman
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Yen-Lin Chu
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Rodney N Trout
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Stephen A Spector
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA; Rady Children's Hospital, San Diego, CA 92123, USA.
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Campbell GR, Bruckman RS, Herns SD, Joshi S, Durden DL, Spector SA. Induction of autophagy by PI3K/MTOR and PI3K/MTOR/BRD4 inhibitors suppresses HIV-1 replication. J Biol Chem 2018; 293:5808-5820. [PMID: 29475942 DOI: 10.1074/jbc.ra118.002353] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 02/21/2018] [Indexed: 12/20/2022] Open
Abstract
In this study, we investigated the effects of the dual phosphatidylinositol 3-kinase/mechanistic target of rapamycin (PI3K/MTOR) inhibitor dactolisib (NVP-BEZ235), the PI3K/MTOR/bromodomain-containing protein 4 (BRD4) inhibitor SF2523, and the bromodomain and extra terminal domain inhibitor JQ1 on the productive infection of primary macrophages with human immunodeficiency type-1 (HIV). These inhibitors did not alter the initial susceptibility of macrophages to HIV infection. However, dactolisib, JQ1, and SF2523 all decreased HIV replication in macrophages in a dose-dependent manner via degradation of intracellular HIV through autophagy. Macrophages treated with dactolisib, JQ1, or SF2523 displayed an increase in LC3B lipidation combined with SQSTM1 degradation without inducing increased cell death. LC3B-II levels were further increased in the presence of pepstatin A suggesting that these inhibitors induce autophagic flux. RNA interference for ATG5 and ATG7 and pharmacological inhibitors of autophagosome-lysosome fusion and of lysosomal hydrolases all blocked the inhibition of HIV. Thus, we demonstrate that the mechanism of PI3K/MTOR and PI3K/MTOR/BRD4 inhibitor suppression of HIV requires the formation of autophagosomes, as well as their subsequent maturation into autolysosomes. These data provide further evidence in support of a role for autophagy in the control of HIV infection and open new avenues for the use of this class of drugs in HIV therapy.
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Affiliation(s)
- Grant R Campbell
- From the Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, California 92093-0672
| | - Rachel S Bruckman
- From the Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, California 92093-0672
| | - Shayna D Herns
- From the Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, California 92093-0672
| | - Shweta Joshi
- the Division of Pediatric Hematology-Oncology, Department of Pediatrics, University of California San Diego, La Jolla, California 92093-0819.,the Rady Children's Hospital, San Diego, California 92123, and
| | - Donald L Durden
- the Division of Pediatric Hematology-Oncology, Department of Pediatrics, University of California San Diego, La Jolla, California 92093-0819.,the Rady Children's Hospital, San Diego, California 92123, and.,SignalRx Pharmaceuticals, Inc., San Diego, California 92130
| | - Stephen A Spector
- From the Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, California 92093-0672, .,the Rady Children's Hospital, San Diego, California 92123, and
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Dara J, Dow A, Cromwell E, Sturdevant CB, Mallewa M, Swanstrom R, Van Rie A, Prasad VR. Multivariable analysis to determine if HIV-1 Tat dicysteine motif is associated with neurodevelopmental delay in HIV-infected children in Malawi. Behav Brain Funct 2015; 11:38. [PMID: 26678821 PMCID: PMC4683967 DOI: 10.1186/s12993-015-0083-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 11/27/2015] [Indexed: 12/02/2022] Open
Abstract
Background HIV-1 Tat protein is implicated in HIV-neuropathogenesis. Tat C31S polymorphism (TatCS) has been associated with milder neuropathology in vitro and in animal models but this has not been addressed in a cohort of HIV-infected adults or children. Methods HIV viral load (VL) in plasma and cerebrospinal fluid (CSF) were determined and plasma HIV tat gene was sequenced. Neurodevelopmental assessment was performed using Bayley Scales of Infant Development III (BSID-III), with scores standardized to Malawian norms. The association between TatCS and BSID-III scores was evaluated using multivariate linear regression. Results Neurodevelopmental assessment and HIV tat genotyping were available for 33 children. Mean age was 19.4 (SD 7.1) months, mean log VL was 5.9 copies/mL (SD 0.1) in plasma and 3.9 copies/mL (SD 0.9) in CSF. The prevalence of TatCC was 27 %. Z-scores for BSID-III subtests ranged from −1.3 to −3.9. TatCC was not associated with higher BSID-III z-scores. Conclusions The hypothesis of milder neuropathology in individuals infected with HIV TatCS was not confirmed in this small cohort of Malawian children. Future studies of tat genotype and neurocognitive disorder should be performed using larger sample sizes and investigate if this finding is due to differences in HIV neuropathogenesis between children and adults.
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Affiliation(s)
- Jasmeen Dara
- Department of Pediatrics, Montefiore Medical Center, Bronx, NY, USA.
| | - Anna Dow
- UNC School of Public Health, University of North Carolina, Chapel Hill, NC, USA.
| | - Elizabeth Cromwell
- UNC School of Public Health, University of North Carolina, Chapel Hill, NC, USA.
| | | | - Macpherson Mallewa
- Malawi-Liverpool Wellcome Trust and Department of Pediatrics, College of Medicine, Blantyre, Malawi.
| | - Ronald Swanstrom
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, USA.
| | - Annelies Van Rie
- UNC School of Public Health, University of North Carolina, Chapel Hill, NC, USA.
| | - Vinayaka R Prasad
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA.
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Carryl H, Swang M, Lawrence J, Curtis K, Kamboj H, Van Rompay KKA, De Paris K, Burke MW. Of mice and monkeys: can animal models be utilized to study neurological consequences of pediatric HIV-1 infection? ACS Chem Neurosci 2015; 6:1276-89. [PMID: 26034832 PMCID: PMC4545399 DOI: 10.1021/acschemneuro.5b00044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pediatric human immunodeficiency virus (HIV-1) infection remains a global health crisis. Children are much more susceptible to HIV-1 neurological impairments than adults, which can be exacerbated by coinfections. Neurological characteristics of pediatric HIV-1 infection suggest dysfunction in the frontal cortex as well as the hippocampus; limited MRI data indicate global cerebral atrophy, and pathological data suggest accelerated neuronal apoptosis in the cortex. An obstacle to pediatric HIV-1 research is a human representative model system. Host-species specificity of HIV-1 limits the ability to model neurological consequences of pediatric HIV-1 infection in animals. Several models have been proposed including neonatal intracranial injections of HIV-1 viral proteins in rats and perinatal simian immunodeficiency virus (SIV) infection of infant macaques. Nonhuman primate models recapitulate the complexity of pediatric HIV-1 neuropathogenesis while rodent models are able to elucidate the role specific viral proteins exert on neurodevelopment. Nonhuman primate models show similar behavioral and neuropathological characteristics to pediatric HIV-1 infection and offer a stage to investigate early viral mechanisms, latency reservoirs, and therapeutic interventions. Here we review the relative strengths and limitations of pediatric HIV-1 model systems.
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Affiliation(s)
- Heather Carryl
- Department of Physiology & Biophysics, College of Medicine, Howard University, Washington, D.C. 20059, United States
| | - Melanie Swang
- Department of Biology, Howard University, Washington, D.C. 20059, United States
| | - Jerome Lawrence
- Department of Biology, Howard University, Washington, D.C. 20059, United States
| | - Kimberly Curtis
- Department of Physiology & Biophysics, College of Medicine, Howard University, Washington, D.C. 20059, United States
| | - Herman Kamboj
- Department of Physiology & Biophysics, College of Medicine, Howard University, Washington, D.C. 20059, United States
| | - Koen K. A. Van Rompay
- California National Primate Research Center, University of California at Davis, Davis, California 95616, United States
| | - Kristina De Paris
- Department of Microbiology and Immunology and Center for AIDS Research School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Mark W. Burke
- Department of Physiology & Biophysics, College of Medicine, Howard University, Washington, D.C. 20059, United States
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12
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Campbell GR, Bruckman RS, Chu YL, Spector SA. Autophagy induction by histone deacetylase inhibitors inhibits HIV type 1. J Biol Chem 2014; 290:5028-5040. [PMID: 25540204 DOI: 10.1074/jbc.m114.605428] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Histone deacetylase inhibitors (HDACi) are being evaluated in a "shock-and-kill" therapeutic approach to reverse human immunodeficiency virus type-1 (HIV) latency from CD4(+) T cells. Using this approach, HDACi have induced HIV RNA synthesis in latently infected cells from some patients. The hope is that the increase in viral production will lead to killing of the infected cell either by the virus itself or by the patient's immune system, a "sterilizing cure." Although administered within the context of combination antiretroviral therapy, the infection of bystander cells remains a concern. In this study, we investigated the effect of HDACi (belinostat, givinostat, panobinostat, romidepsin, and vorinostat) on the productive infection of macrophages. We demonstrate that the HDACi tested do not alter the initial susceptibility of macrophages to HIV infection. However, we demonstrate that HDACi decrease HIV release from macrophages in a dose-dependent manner (belinostat < givinostat < vorinostat < panobinostat < romidepsin) via degradation of intracellular HIV through the canonical autophagy pathway. This mechanism involves unc-51-like autophagy-activating kinase 1 (ULK1) and the inhibition of the mammalian target of rapamycin and requires the formation of autophagosomes and their maturation into autolysosomes in the absence of increased cell death. These data provide further evidence in support of a role for autophagy in the control of HIV infection and suggest that careful consideration of off-target effects will be essential if HDACi are to be a component of a multipronged approach to eliminate latently infected cells.
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Affiliation(s)
- Grant R Campbell
- From the Department of Pediatrics, Division of Infectious Diseases, University of California at San Diego, La Jolla, California 92093-0672.
| | - Rachel S Bruckman
- From the Department of Pediatrics, Division of Infectious Diseases, University of California at San Diego, La Jolla, California 92093-0672
| | - Yen-Lin Chu
- From the Department of Pediatrics, Division of Infectious Diseases, University of California at San Diego, La Jolla, California 92093-0672
| | - Stephen A Spector
- From the Department of Pediatrics, Division of Infectious Diseases, University of California at San Diego, La Jolla, California 92093-0672.
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13
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Ortega M, Heaps JM, Joska J, Vaida F, Seedat S, Stein DJ, Paul R, Ances BM. HIV clades B and C are associated with reduced brain volumetrics. J Neurovirol 2014; 19:479-87. [PMID: 24078556 DOI: 10.1007/s13365-013-0202-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 07/08/2013] [Accepted: 08/20/2013] [Indexed: 12/16/2022]
Abstract
The human immunodeficiency virus (HIV) has multiple genetic clades with varying prevalence throughout the world. Both HIV clade C (HIV-C) and HIV clade B (HIV-B) can cause cognitive impairment, but it is unclear if these clades are characterized by similar patterns of brain dysfunction. We examined brain volumetrics and neuropsychological performance among highly active antiretroviral therapy (HAART)-naïve HIV-B and HIV-C participants. Thirty-four HAART-naïve HIV-infected (HIV+) participants [17 HIV-B (USA); 17 HIV-C (South Africa)] and 34 age- and education-matched HIV-uninfected (HIV−) participants were evaluated. All participants underwent similar laboratory, neuropsychological, and neuroimaging studies. Brain volume measures were assessed within the caudate, putamen, amygdala, thalamus, hippocampus, corpus callosum, and cortical (gray and white matter) structures. A linear model that included HIV status, region, and their interaction assessed the effects of the virus on brain volumetrics. HIV− and HIV+ individuals were similar in age. On laboratory examination, HIV-C participants had lower CD4 cell counts and higher plasma HIV viral loads than HIV-B individuals. In general, HIV+ participants performed significantly worse on neuropsychological measures of processing speed and memory and had significantly smaller relative volumetrics within the thalamus, hippocampus, corpus callosum, and cortical gray and white matter compared to the respective HIV− controls. Both HIV-B and HIV-C are associated with similar volumetric declines when compared to matched HIV− controls. HIV-B and HIV-C were associated with significant reductions in brain volumetrics and poorer neuropsychological performance; however, no specific effect of HIV clade subtype was evident. These findings suggest that HIV-B and HIV-C both detrimentally affect brain integrity.
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14
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Tyor W, Fritz-French C, Nath A. Effect of HIV clade differences on the onset and severity of HIV-associated neurocognitive disorders. J Neurovirol 2013; 19:515-22. [PMID: 24129908 DOI: 10.1007/s13365-013-0206-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/20/2013] [Accepted: 09/09/2013] [Indexed: 12/13/2022]
Abstract
The effects of evolutionary pressure on human immunodeficiency virus-1 (HIV) have resulted in a variety of clades and recombinants. The functional implications of HIV clades on disease onset and progression of HIV-associated neurocognitive disorders (HAND) have been suggested by clinical and basic science studies, which will be reviewed in detail. Some clinical studies suggest that patients infected with clade D show the greatest propensity for developing HIV-associated dementia (HAD) followed by clades B, C, and A, respectively. However, there are conflicting reports. This review summarizes clinical studies that have assessed behavioral abnormalities and HIV clade type in HAND patients, focusing on the clades stated above. The limitations include variations in testing used to define the cohorts, patient sample size, lack of HIV clade characterization, combination antiretroviral therapy (cART) availability, and other factors, which are highlighted and compared between clinical studies performed primarily in Africa and India. Basic science studies provide substantial evidence that HIV clade differences can result in varying degrees of neuropathology and are also reviewed in some detail. These studies indicate that there are a number of clade differences, most notably in Tat, that result in different degrees of neurovirulence or neuropathological effects in vitro and in a mouse model of HAND. In order to confirm the hypothesis that HIV clade differences are important determinants of HAND pathogenesis, larger, longitudinal studies that employ standard definitions of HAND and HIV clade testing must be performed. In a larger sense, HAND continues to be highly prevalent despite the advent of cART, and therefore, further studies into HAND pathogenesis are critical to develop better therapies.
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Affiliation(s)
- William Tyor
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA,
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15
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Bertrand SJ, Aksenova MV, Mactutus CF, Booze RM. HIV-1 Tat protein variants: critical role for the cysteine region in synaptodendritic injury. Exp Neurol 2013; 248:228-35. [PMID: 23811015 DOI: 10.1016/j.expneurol.2013.06.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 05/24/2013] [Accepted: 06/18/2013] [Indexed: 01/08/2023]
Abstract
HIV-1 enters the central nervous system early in infection; although HIV-1 does not directly infect neurons, HIV-1 may cause a variety of neurological disorders. Neuronal loss has been found in HIV-1, but synaptodendritic injury is more closely associated with the neurocognitive disorders of HIV-1. The HIV-1 transactivator of transcription (Tat) protein causes direct and indirect damage to neurons. The cysteine rich domain (residues 22-37) of Tat is important for producing neuronal death; however, little is known about the effects of the Tat protein functional domains on the dendritic network. The ability of HIV-1 Tat 1-101 Clades B and C, Tat 1-86 and Tat 1-72 proteins, as well as novel peptides (truncated 47-57, 1-72δ31-61, and 1-86 with a mutation at Cys22) to produce early synaptodendritic injury (24h), relative to later cell death (48h), was examined using cell culture. Treatment of primary hippocampal neurons with Tat proteins 1-72, 1-86 and 1-101B produced a significant early reduction in F-actin labeled puncta, implicating that these peptides play a role in synaptodendritic injury. Variants with a mutation, deletion, or lack of a cysteine rich region (1-86[Cys22], 1-101C, 1-72δ31-61, or 47-57) did not cause a significant reduction in F-actin rich puncta. Tat 1-72, 1-86, and 1-101B proteins did not significantly differ from one another, indicating that the second exon (73-86 or 73-101) does not play a significant role in the reduction of F-actin puncta. Conversely, peptides with a mutation, deletion, or lack of the cysteine rich domain (22-37) failed to produce a loss of F-actin puncta, indicating that the cysteine rich domain plays a key role in synaptodendritic injury. Collectively, these results suggest that for Tat proteins, 1) synaptodendritic injury occurs early, relative to cell death, and 2) the cysteine rich domain of the first exon is key for synaptic loss. Preventing such early synaptic loss may attenuate HIV-1 associated neurocognitive disorders.
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Affiliation(s)
- Sarah J Bertrand
- Laboratory Program in Behavioral Neuroscience, Department of Psychology, University of South Carolina, Barnwell College Building, 1512 Pendleton Street, Columbia, SC 29208, USA
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16
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Wright CA, Nance JA, Johnson EM. Effects of Tat proteins and Tat mutants of different human immunodeficiency virus type 1 clades on glial JC virus early and late gene transcription. J Gen Virol 2012; 94:514-523. [PMID: 23152365 DOI: 10.1099/vir.0.047902-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Polyomavirus JC (JCV) is the aetiological agent of progressive multifocal leukoencephalopathy (PML), a frequently fatal infection of the brain afflicting nearly 4% of AIDS patients in the USA. Human immunodeficiency virus type 1 (HIV-1) Tat, acting together with cellular proteins at the JCV non-coding control region (NCCR), can stimulate JCV DNA transcription and replication. Tat in the brain is secreted by HIV-1-infected cells and incorporated by oligodendroglia, cells capable of infection by JCV. Thus far the effects of Tat on JCV have been studied primarily with protein encoded by the HIV-1 B clade most common in North America. Here, we determine the abilities of Tat from different HIV-1 clades to alter JCV early and late gene transcription and DNA replication initiated at the JCV origin. Tat from all clades tested stimulates both JCV early and late gene promoters, with clade B Tat being significantly most effective. Tat proteins from the HIV-1 clades display parallel patterns of differences in their effects on HIV-1 and JCV transcription, suggesting that Tat effects in both cases are mediated by the same cellular proteins. Clade B Tat is most effective at directing Smad mediators of tumour growth factor beta and cellular partner Purα to the NCCR. Tat proteins from all non-B clades inhibit initiation of JCV DNA replication. The effectiveness of HIV-1 clade B Tat at promoting JCV transcriptional and replicative processes highlights a need for further investigation to determine which molecular aspects of Tat from distinct HIV-1 substrains can contribute to the course of PML development in neuroAIDS.
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Affiliation(s)
- Clayton A Wright
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23510, USA
| | - Jonas A Nance
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23510, USA
| | - Edward M Johnson
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23510, USA
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17
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Abstract
HIV enters the brain during the early stages of initial infection and can result in a complicated array of diverse neurological dysfunctions. While neuronal injury and loss are at the heart of neurological decline and HIV-associated neuropathology, HIV does not productively infect neurons and the effects of HIV on neurons may be described as largely indirect. Viral proteins released from infected cells in the CNS are a well-characterized source of neuronal toxicity. Likewise, host-derived inflammatory cytokines and chemokines released from infected and/or activated glial cells can damage neurons, as well. Newly identified host-virus interactions and the current state of our knowledge regarding HIV-associated neuronal toxicity will be addressed in this review. Aspects of HIV-associated neurotoxic mechanisms, patterns of neuronal damage, viral effects on neurotrophic signaling, clade variations and comorbid substance abuse will be discussed. Recent advances in our understanding of the impact of HIV infection of the CNS on neuronal dysfunction and cell death will also be highlighted.
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Affiliation(s)
- Jane Kovalevich
- Department of Neuroscience, Temple University School of Medicine, Education & Research Building, 3500 North Broad Street, Philadelphia, PA 19140-5104, USA
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18
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Adams SM, Aksenova MV, Aksenov MY, Mactutus CF, Booze RM. Soy isoflavones genistein and daidzein exert anti-apoptotic actions via a selective ER-mediated mechanism in neurons following HIV-1 Tat(1-86) exposure. PLoS One 2012; 7:e37540. [PMID: 22629415 PMCID: PMC3358258 DOI: 10.1371/journal.pone.0037540] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 04/24/2012] [Indexed: 01/02/2023] Open
Abstract
Background HIV-1 viral protein Tat partially mediates the neural dysfunction and neuronal cell death associated with HIV-1 induced neurodegeneration and neurocognitive disorders. Soy isoflavones provide protection against various neurotoxic insults to maintain neuronal function and thus help preserve neurocognitive capacity. Methodology/Principal Findings We demonstrate in primary cortical cell cultures that 17β-estradiol or isoflavones (genistein or daidzein) attenuate Tat1–86-induced expression of apoptotic proteins and subsequent cell death. Exposure of cultured neurons to the estrogen receptor antagonist ICI 182,780 abolished the anti-apoptotic actions of isoflavones. Use of ERα or ERβ specific antagonists determined the involvement of both ER isoforms in genistein and daidzein inhibition of caspase activity; ERβ selectively mediated downregulation of mitochondrial pro-apoptotic protein Bax. The findings suggest soy isoflavones effectively diminished HIV-1 Tat-induced apoptotic signaling. Conclusions/Significance Collectively, our results suggest that soy isoflavones represent an adjunctive therapeutic option with combination anti-retroviral therapy (cART) to preserve neuronal functioning and sustain neurocognitive abilities of HIV-1 infected persons.
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Affiliation(s)
- Sheila M Adams
- Department of Psychology, University of South Carolina, Columbia, South Carolina, United States of America.
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19
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Hochman S, Kim K. The Impact of HIV Coinfection on Cerebral Malaria Pathogenesis. JOURNAL OF NEUROPARASITOLOGY 2012; 3:235547. [PMID: 22545215 PMCID: PMC3336366 DOI: 10.4303/jnp/235547] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
HIV infection is widespread throughout the world and is especially prevalent in sub-Saharan Africa and Asia. Similarly, Plasmodium falciparum, the most common cause of severe malaria, affects large areas of sub-Saharan Africa, the Indian subcontinent, and Southeast Asia. Although initial studies suggested that HIV and malaria had independent impact upon patient outcomes, recent studies have indicated a more significant interaction. Clinical studies have shown that people infected with HIV have more frequent and severe episodes of malaria, and parameters of HIV disease progression worsen in individuals during acute malaria episodes. However, the effect of HIV on development of cerebral malaria, a manifestation of P. falciparum infection that is frequently fatal, has not been characterized. We review clinical and basic science studies pertaining to HIV and malaria coinfection and cerebral malaria in particular in order to highlight the likely role HIV plays in exacerbating cerebral malaria pathogenesis.
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Affiliation(s)
- Sarah Hochman
- Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA
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20
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Abstract
PURPOSE OF REVIEW Macrophages play an important role in HIV-1 pathogenesis and contribute to the establishment of the viral reservoir responsible for continuous virus production. This review will discuss new insights into HIV-1 infection in macrophages and the effect of infection on immune function and pathology. RECENT FINDINGS New cellular factors interacting with various steps of the HIV-1 replication cycle, such as entry, integration, transcription, and assembly of new viral progeny, have been identified. Cellular and viral microRNAs have been shown to regulate virus replication, promote viral latency, and prolong cell survival. Interference with innate immune functions, like phagocytosis, autophagy, cytokine production, and T-cell activation by HIV-1 has been found to contribute to virus replication and latency. Growing evidence indicates an important role of infected macrophages in a variety of HIV-1-associated diseases, including neurocognitive disorders. SUMMARY Under combined antiretroviral therapy (cART), HIV-1 continues to persist in macrophages. Better understanding of HIV-1 infection in macrophages may lead to new adjunctive therapies to improve cART, specifically targeting the viral reservoir and ameliorating tissue-specific diseases.
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21
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Zou S, Fitting S, Hahn YK, Welch SP, El-Hage N, Hauser KF, Knapp PE. Morphine potentiates neurodegenerative effects of HIV-1 Tat through actions at μ-opioid receptor-expressing glia. Brain 2011; 134:3616-31. [PMID: 22102648 DOI: 10.1093/brain/awr281] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Individuals infected with human immunodeficiency virus-1 who abuse opiates can have a higher incidence of virus-associated neuropathology. Human immunodeficiency virus does not infect neurons, but viral proteins such as transactivator of transcription and glycoprotein 120, originating from infected glia, are neurotoxic. Moreover, functional changes in glial cells that enhance inflammation and reduce trophic support are increasingly implicated in human immunodeficiency virus neuropathology. In previous studies, co-exposure with morphine enhanced transactivator of transcription neurotoxicity towards cultured striatal neurons. Since those cultures contained µ-opioid receptor-expressing astroglia and microglia, and since glia are the principal site of infection in the central nervous system, we hypothesized that morphine synergy might be glially mediated. A 60 hour, repeated measures paradigm and multiple co-culture models were used to investigate the cellular basis for opiate-enhanced human immunodeficiency virus neurotoxicity. Morphine co-exposure significantly enhanced transactivator of transcription-induced neuron death when glia were present. Synergistic effects of morphine on transactivator of transcription neurotoxicity were greatest with neuron-glia contact, but also occurred to a lesser extent with glial conditioned medium. Importantly, synergy was lost if glia, but not neurons, lacked µ-opioid receptors, indicating that opiate interactions with human immunodeficiency virus converge at the level of µ-opioid receptor-expressing glia. Morphine enhanced transactivator of transcription-induced inflammatory effectors released by glia, elevating reactive oxygen species, increasing 3-nitrotyrosine production by microglia, and reducing the ability of glia to buffer glutamate. But neuron survival was reduced even more with glial contact than with exposure to conditioned medium, suggesting that noxious elements associated with cell contact augment the toxicity due to soluble factors. Similar morphine-transactivator of transcription synergy was also observed in studies with the clade C sequence of HIV-1 transactivator of transcription, which did not cause neuron death unless morphine was present. Several paradoxical observations related to opiate effects were noted when µ-opioid receptors were specifically ablated from either glia or neurons. This suggests that µ-opioid receptor loss in isolated cell types can fundamentally distort cell-to-cell signalling, revealing opponent processes that may exist in individual cell types. Our findings show the critical role of glia in orchestrating neurotoxic interactions of morphine and transactivator of transcription, and support the emerging concept that combined exposure to opiates and human immunodeficiency virus drives enhanced pathology within the central nervous system.
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Affiliation(s)
- Shiping Zou
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298, USA
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Chi X, Amet T, Byrd D, Chang KH, Shah K, Hu N, Grantham A, Hu S, Duan J, Tao F, Nicol G, Yu Q. Direct effects of HIV-1 Tat on excitability and survival of primary dorsal root ganglion neurons: possible contribution to HIV-1-associated pain. PLoS One 2011; 6:e24412. [PMID: 21912693 PMCID: PMC3166319 DOI: 10.1371/journal.pone.0024412] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 08/10/2011] [Indexed: 11/18/2022] Open
Abstract
The vast majority of people living with human immunodeficiency virus type 1 (HIV-1) have pain syndrome, which has a significant impact on their quality of life. The underlying causes of HIV-1-associated pain are not likely attributable to direct viral infection of the nervous system due to the lack of evidence of neuronal infection by HIV-1. However, HIV-1 proteins are possibly involved as they have been implicated in neuronal damage and death. The current study assesses the direct effects of HIV-1 Tat, one of potent neurotoxic viral proteins released from HIV-1-infected cells, on the excitability and survival of rat primary dorsal root ganglion (DRG) neurons. We demonstrated that HIV-1 Tat triggered rapid and sustained enhancement of the excitability of small-diameter rat primary DRG neurons, which was accompanied by marked reductions in the rheobase and resting membrane potential (RMP), and an increase in the resistance at threshold (R(Th)). Such Tat-induced DRG hyperexcitability may be a consequence of the inhibition of cyclin-dependent kinase 5 (Cdk5) activity. Tat rapidly inhibited Cdk5 kinase activity and mRNA production, and roscovitine, a well-known Cdk5 inhibitor, induced a very similar pattern of DRG hyperexcitability. Indeed, pre-application of Tat prevented roscovitine from having additional effects on the RMP and action potentials (APs) of DRGs. However, Tat-mediated actions on the rheobase and R(Th) were accelerated by roscovitine. These results suggest that Tat-mediated changes in DRG excitability are partly facilitated by Cdk5 inhibition. In addition, Cdk5 is most abundant in DRG neurons and participates in the regulation of pain signaling. We also demonstrated that HIV-1 Tat markedly induced apoptosis of primary DRG neurons after exposure for longer than 48 h. Together, this work indicates that HIV-1 proteins are capable of producing pain signaling through direct actions on excitability and survival of sensory neurons.
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Affiliation(s)
- Xianxun Chi
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Tohti Amet
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Daniel Byrd
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Kuei-Hua Chang
- Department of Chemistry and Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, United States of America
| | - Kavita Shah
- Department of Chemistry and Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, United States of America
| | - Ningjie Hu
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Ayslinn Grantham
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Sishun Hu
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Jianhong Duan
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Feng Tao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Grant Nicol
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Qigui Yu
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
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