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Liu Z, Julius P, Mudenda V, Kang G, Del Valle L, West JT, Wood C. Limited HIV-associated neuropathologies and lack of immune activation in sub-saharan African individuals with late-stage subtype C HIV-1 infection. J Neurovirol 2024:10.1007/s13365-024-01219-6. [PMID: 38943022 DOI: 10.1007/s13365-024-01219-6] [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: 03/19/2024] [Revised: 06/04/2024] [Accepted: 06/07/2024] [Indexed: 06/30/2024]
Abstract
Although previous studies have suggested that subtype B HIV-1 proviruses in the brain are associated with physiological changes and immune activation accompanied with microgliosis and astrogliosis, and indicated that both HIV-1 subtype variation and geographical location might influence the neuropathogenicity of HIV-1 in the brain. The natural course of neuropathogenesis of the most widespread subtype C HIV-1 has not been adequately investigated, especially for people living with HIV (PLWH) in sub-Saharan Africa. To characterize the natural neuropathology of subtype C HIV-1, postmortem frontal lobe and basal ganglia tissues were collected from nine ART-naïve individuals who died of late-stage AIDS with subtype C HIV-1 infection, and eight uninfected deceased individuals as controls. Histological staining was performed on all brain tissues to assess brain pathologies. Immunohistochemistry (IHC) against CD4, p24, Iba-1, GFAP, and CD8 in all brain tissues was conducted to evaluate potential viral production and immune activation. Histological results showed mild perivascular cuffs of lymphocytes only in a minority of the infected individuals. Viral capsid p24 protein was only detected in circulating immune cells of one infected individual, suggesting a lack of productive HIV-1 infection of the brain even at the late-stage of AIDS. Notably, similar levels of Iba-1 or GFAP between HIV + and HIV- brain tissues indicated a lack of microgliosis and astrogliosis, respectively. Similar levels of CD8 + cytotoxic T lymphocyte (CTL) infiltration between HIV + and HIV- brain tissues indicated CTL were not likely to be involved within subtype C HIV-1 infected participants of this cohort. Results from this subtype C HIV-1 study suggest that there is a lack of productive infection and limited neuropathogenesis by subtype C HIV-1 even at late-stage disease, which is in contrast to what was reported for subtype B HIV-1 by other investigators.
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Affiliation(s)
- Zhou Liu
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Interdisciplinary Oncology, Louisiana Cancer Research Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Peter Julius
- Department of Pathology and Microbiology, University of Zambia School of Medicine, Lusaka, Zambia
| | - Victor Mudenda
- Department of Pathology, University Teaching Hospital, Lusaka, Zambia
| | - Guobin Kang
- Department of Interdisciplinary Oncology, Louisiana Cancer Research Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Luis Del Valle
- Department of Pathology and Medicine, Louisiana Cancer Research Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - John T West
- Department of Interdisciplinary Oncology, Louisiana Cancer Research Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Charles Wood
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
- Department of Interdisciplinary Oncology, Louisiana Cancer Research Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA.
- , 1700 Tulane Avenue, LCRC Rm 614, New Orleans, LA, 70112, USA.
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St-Pierre MK, VanderZwaag J, Loewen S, Tremblay MÈ. All roads lead to heterogeneity: The complex involvement of astrocytes and microglia in the pathogenesis of Alzheimer’s disease. Front Cell Neurosci 2022; 16:932572. [PMID: 36035256 PMCID: PMC9413962 DOI: 10.3389/fncel.2022.932572] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/11/2022] [Indexed: 01/04/2023] Open
Abstract
In recent years, glial cells have been acknowledged as key players in the pathogenesis of Alzheimer’s disease (AD), a neurodegenerative condition in which an accumulation of intracellular neurofibrillary tangles and extracellular fibrillar amyloid beta is notably observed in the central nervous system. Genome-wide association studies have shown, both in microglia and astrocytes, an increase in gene variants associated with a higher risk of developing late-onset AD. Microglia, the resident innate immune cells of the brain, and astrocytes, glial cells crucial for vascular integrity and neuronal support, both agglomerate near amyloid beta plaques and dystrophic neurites where they participate in the elimination of these harmful parenchymal elements. However, their role in AD pathogenesis has been challenging to resolve due to the highly heterogeneous nature of these cell populations, i.e., their molecular, morphological, and ultrastructural diversity, together with their ever-changing responsiveness and functions throughout the pathological course of AD. With the recent expansions in the field of glial heterogeneity through innovative advances in state-of-the-art microscopy and -omics techniques, novel concepts and questions arose, notably pertaining to how the diverse microglial and astrocytic states interact with each other and with the AD hallmarks, and how their concerted efforts/actions impact the progression of the disease. In this review, we discuss the recent advances and findings on the topic of glial heterogeneity, particularly focusing on the relationships of these cells with AD hallmarks (e.g., amyloid beta plaques, neurofibrillary tangles, synaptic loss, and dystrophic neurites) in murine models of AD pathology and post-mortem brain samples of patients with AD.
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Affiliation(s)
- Marie-Kim St-Pierre
- Département de Médecine Moléculaire, Université Laval, Quebec City, QC, Canada
- Axe Neurosciences, Center de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Jared VanderZwaag
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
| | - Sophia Loewen
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Marie-Ève Tremblay
- Département de Médecine Moléculaire, Université Laval, Quebec City, QC, Canada
- Axe Neurosciences, Center de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neurology and Neurosurgery Department, McGill University, Montréal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Center for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- *Correspondence: Marie-Ève Tremblay,
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Silva FS, de Souza KSC, Galdino OA, de Moraes MV, Ishikawa U, Medeiros MA, Lima JPMS, de Paula Medeiros KC, da Silva Farias NB, de Araújo Júnior RF, de Rezende AA, Abreu BJ, de Oliveira MF. Hyperbaric oxygen therapy mitigates left ventricular remodeling, upregulates MMP-2 and VEGF, and inhibits the induction of MMP-9, TGF-β1, and TNF-α in streptozotocin-induced diabetic rat heart. Life Sci 2022; 295:120393. [PMID: 35167880 DOI: 10.1016/j.lfs.2022.120393] [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: 11/08/2021] [Revised: 02/02/2022] [Accepted: 02/06/2022] [Indexed: 11/17/2022]
Abstract
AIMS Hyperbaric oxygen (HBO) therapy has been widely used for the adjunctive treatment of diabetic wounds, and is currently known to influence left ventricular (LV) function. However, morphological and molecular repercussions of the HBO in the diabetic myocardium remain to be described. We aimed to investigate whether HBO therapy would mitigate adverse LV remodeling caused by streptozotocin (STZ)-induced diabetes. MAIN METHODS Sixty-day-old Male Wistar rats were divided into four groups: Control (n = 8), HBO (n = 7), STZ (n = 10), and STZ + HBO (n = 8). Diabetes was induced by a single STZ injection (60 mg/kg, i.p.). HBO treatment (100% oxygen at 2.5 atmospheres absolute, 60 min/day, 5 days/week) lasted for 5 weeks. LV morphology was evaluated using histomorphometry. Gene expression analyzes were performed for LV collagens I (Col1a1) and III (Col3a1), matrix metalloproteinases 2 (Mmp2) and 9 (Mmp9), and transforming growth factor-β1 (Tgfb1). The Immunoexpression of cardiac tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) were also quantified. KEY FINDINGS HBO therapy prevented LV concentric remodeling, heterogeneous myocyte hypertrophy, and fibrosis in diabetic rats associated with attenuation of leukocyte infiltration. HBO therapy also increased Mmp2 gene expression, and inhibited the induction of Tgfb1 and Mmp9 mRNAs caused by diabetes, and normalized TNF-α and VEGF protein expression. SIGNIFICANCE HBO therapy had protective effects for the LV structure in STZ-diabetic rats and ameliorated expression levels of genes involved in cardiac collagen turnover, as well as pro-inflammatory and pro-angiogenic signaling.
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Affiliation(s)
- Flávio Santos Silva
- Department of Health Sciences, Federal Rural University of the Semi-Arid, Mossoró, Brazil.
| | | | - Ony Araujo Galdino
- Department of Clinical and Toxicological Analysis, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | - Uta Ishikawa
- Department of Morphology, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | | | | | | | | | - Adriana Augusto de Rezende
- Department of Clinical and Toxicological Analysis, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Bento João Abreu
- Department of Morphology, Federal University of Rio Grande do Norte, Natal, Brazil
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Crucial Role of Central Nervous System as a Viral Anatomical Compartment for HIV-1 Infection. Microorganisms 2021; 9:microorganisms9122537. [PMID: 34946138 PMCID: PMC8705402 DOI: 10.3390/microorganisms9122537] [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: 06/08/2021] [Revised: 07/11/2021] [Accepted: 07/17/2021] [Indexed: 11/17/2022] Open
Abstract
The chronic infection established by the human immunodeficiency virus 1 (HIV-1) produces serious CD4+ T cell immunodeficiency despite the decrease in HIV-1 ribonucleic acid (RNA) levels and the raised life expectancy of people living with HIV-1 (PLWH) through treatment with combined antiretroviral therapies (cART). HIV-1 enters the central nervous system (CNS), where perivascular macrophages and microglia are infected. Serious neurodegenerative symptoms related to HIV-associated neurocognitive disorders (HAND) are produced by infection of the CNS. Despite advances in the treatment of this infection, HAND significantly contribute to morbidity and mortality globally. The pathogenesis and the role of inflammation in HAND are still incompletely understood. Principally, growing evidence shows that the CNS is an anatomical reservoir for viral infection and replication, and that its compartmentalization can trigger the evolution of neurological damage and thus make virus eradication more difficult. In this review, important concepts for understanding HAND and neuropathogenesis as well as the viral proteins involved in the CNS as an anatomical reservoir for HIV infection are discussed. In addition, an overview of the recent advancements towards therapeutic strategies for the treatment of HAND is presented. Further neurological research is needed to address neurodegenerative difficulties in people living with HIV, specifically regarding CNS viral reservoirs and their effects on eradication.
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Sil S, Thangaraj A, Chivero ET, Niu F, Kannan M, Liao K, Silverstein PS, Periyasamy P, Buch S. HIV-1 and drug abuse comorbidity: Lessons learned from the animal models of NeuroHIV. Neurosci Lett 2021; 754:135863. [PMID: 33794296 DOI: 10.1016/j.neulet.2021.135863] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023]
Abstract
Various research studies that have investigated the association between HIV infection and addiction underpin the role of various drugs of abuse in impairing immunological and non-immunological pathways of the host system, ultimately leading to augmentation of HIV infection and disease progression. These studies have included both in vitro and in vivo animal models wherein investigators have assessed the effects of various drugs on several disease parameters to decipher the impact of drugs on both HIV infection and progression of HIV-associated neurocognitive disorders (HAND). However, given the inherent limitations in the existing animal models of HAND, these investigations only recapitulated specific aspects of the disease but not the complex human syndrome. Despite the inability of HIV to infect rodents over the last 30 years, multiple strategies have been employed to develop several rodent models of HAND. While none of these models can accurately mimic the overall pathophysiology of HAND, they serve the purpose of modeling some unique aspects of HAND. This review provides an overview of various animal models used in the field and a careful evaluation of methodological strengths and limitations inherent in both the model systems and study designs to understand better how the various animal models complement one another.
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Affiliation(s)
- Susmita Sil
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Annadurai Thangaraj
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Ernest T Chivero
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Fang Niu
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Muthukumar Kannan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Ke Liao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Peter S Silverstein
- School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, 64108, USA
| | - Palsamy Periyasamy
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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Hermes DJ, Yadav-Samudrala BJ, Xu C, Paniccia JE, Meeker RB, Armstrong ML, Reisdorph N, Cravatt BF, Mackie K, Lichtman AH, Ignatowska-Jankowska BM, Lysle DT, Fitting S. GPR18 drives FAAH inhibition-induced neuroprotection against HIV-1 Tat-induced neurodegeneration. Exp Neurol 2021; 341:113699. [PMID: 33736974 PMCID: PMC8984429 DOI: 10.1016/j.expneurol.2021.113699] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 02/05/2021] [Accepted: 03/11/2021] [Indexed: 02/03/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) is known to provoke microglial immune responses which likely play a paramount role in the development of chronic neuroinflammatory conditions and neuronal damage related to HIV-1 associated neurocognitive disorders (HAND). In particular, HIV-1 Tat protein is a proinflammatory neurotoxin which predisposes neurons to synaptodendritic injury. Drugs targeting the degradative enzymes of endogenous cannabinoids have shown promise in reducing inflammation with minimal side effects in rodent models. Considering that markers of neuroinflammation can predict the extent of neuronal injury in HAND patients, we evaluated the neurotoxic effect of HIV-1 Tat-exposed microglia following blockade of fatty acid amid hydrolyze (FAAH), a catabolic enzyme responsible for degradation of endocannabinoids, e.g. anandamide (AEA). In the present study, cultured murine microglia were incubated with Tat and/or a FAAH inhibitor (PF3845). After 24 h, cells were imaged for morphological analysis and microglial conditioned media (MCM) was collected. Frontal cortex neuron cultures (DIV 7–11) were then exposed to MCM, and neurotoxicity was assessed via live cell calcium imaging and staining of actin positive dendritic structures. Results demonstrate a strong attenuation of microglial responses to Tat by PF3845 pretreatment, which is indicated by 1) microglial changes in morphology to a less proinflammatory phenotype using fractal analysis, 2) a decrease in release of neurotoxic cytokines/chemokines (MCP-1/CCL2) and matrix metalloproteinases (MMPs; MMP-9) using ELISA/multiplex assays, and 3) enhanced production of endocannabinoids (AEA) using LC/MS/MS. Additionally, PF3845’s effects on Tat-induced microglial-mediated neurotoxicity, decreased dysregulation of neuronal intracellular calcium and prevented the loss of actin-positive staining and punctate structure in frontal cortex neuron cultures. Interestingly, these observed neuroprotective effects appeared to be independent of cannabinoid receptor activity (CB1R & CB2R). We found that a purported GPR18 antagonist, CID-85469571, blocked the neuroprotective effects of PF3845 in all experiments. Collectively, these experiments increase understanding of the role of FAAH inhibition and Tat in mediating microglial neurotoxicity in the HAND condition.
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Affiliation(s)
- Douglas J Hermes
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America.
| | - Barkha J Yadav-Samudrala
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Changqing Xu
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Jacqueline E Paniccia
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Rick B Meeker
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Michael L Armstrong
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Denver, CO, United States of America
| | - Nichole Reisdorph
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Denver, CO, United States of America
| | - Benjamin F Cravatt
- Department of Chemistry, Scripps Research Institute, La Jolla, CA, United States of America
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States of America
| | - Aron H Lichtman
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States of America
| | | | - Donald T Lysle
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Sylvia Fitting
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America.
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Jha NK, Sharma A, Jha SK, Ojha S, Chellappan DK, Gupta G, Kesari KK, Bhardwaj S, Shukla SD, Tambuwala MM, Ruokolainen J, Dua K, Singh SK. Alzheimer's disease-like perturbations in HIV-mediated neuronal dysfunctions: understanding mechanisms and developing therapeutic strategies. Open Biol 2020; 10:200286. [PMID: 33352062 PMCID: PMC7776571 DOI: 10.1098/rsob.200286] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/27/2020] [Indexed: 01/10/2023] Open
Abstract
Excessive exposure to toxic substances or chemicals in the environment and various pathogens, including viruses and bacteria, is associated with the onset of numerous brain abnormalities. Among them, pathogens, specifically viruses, elicit persistent inflammation that plays a major role in Alzheimer's disease (AD) as well as dementia. AD is the most common brain disorder that affects thought, speech, memory and ability to execute daily routines. It is also manifested by progressive synaptic impairment and neurodegeneration, which eventually leads to dementia following the accumulation of Aβ and hyperphosphorylated Tau. Numerous factors contribute to the pathogenesis of AD, including neuroinflammation associated with pathogens, and specifically viruses. The human immunodeficiency virus (HIV) is often linked with HIV-associated neurocognitive disorders (HAND) following permeation through the blood-brain barrier (BBB) and induction of persistent neuroinflammation. Further, HIV infections also exhibited the ability to modulate numerous AD-associated factors such as BBB regulators, members of stress-related pathways as well as the amyloid and Tau pathways that lead to the formation of amyloid plaques or neurofibrillary tangles accumulation. Studies regarding the role of HIV in HAND and AD are still in infancy, and potential link or mechanism between both is not yet established. Thus, in the present article, we attempt to discuss various molecular mechanisms that contribute to the basic understanding of the role of HIV-associated neuroinflammation in AD and HAND. Further, using numerous growth factors and drugs, we also present possible therapeutic strategies to curb the neuroinflammatory changes and its associated sequels.
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Affiliation(s)
- Niraj Kumar Jha
- Department of Biotechnology, School of Engineering and Technology (SET), Sharda University, Greater Noida, UP 201310, India
| | - Ankur Sharma
- Department of Life Science, School of Basic Science and Research (SBSR), Sharda University, Greater Noida, UP 201310, India
| | - Saurabh Kumar Jha
- Department of Biotechnology, School of Engineering and Technology (SET), Sharda University, Greater Noida, UP 201310, India
| | - Shreesh Ojha
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, PO Box 17666, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Dinesh Kumar Chellappan
- Department of Life Sciences, School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur 57000, Malaysia
| | - Gaurav Gupta
- School of Phamacy, Suresh Gyan Vihar University, Jagatpura, Mahal Road, Jaipur, India
| | - Kavindra Kumar Kesari
- Department of Applied Physics, School of Science, Aalto University, Espoo 00076, Finland
| | - Shanu Bhardwaj
- Department of Biotechnology, HIMT, Greater Noida, CCS University, UP, India
| | - Shakti D. Shukla
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute (HMRI) and School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Murtaza M. Tambuwala
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, County Londonderry, BT52 1SA, UK
| | - Janne Ruokolainen
- Department of Applied Physics, School of Science, Aalto University, Espoo 00076, Finland
| | - Kamal Dua
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute (HMRI) and School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Sydney, New South Wales 2007, Australia
- School of Pharmaceutical Sciences, Shoolini University of Biotechnology and Management Sciences, PO Box 9, Solan, Himachal Pradesh 173229, India
| | - Sandeep Kumar Singh
- Department of Biomedical Research, Centre of Biomedical Research, SGPGI Campus, Lucknow 226014, UP, India
- Biological Science, Indian Scientific Education and Technology Foundation, Lucknow 226002, UP, India
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Wu MM, Thayer SA. HIV Tat Protein Selectively Impairs CB 1 Receptor-Mediated Presynaptic Inhibition at Excitatory But Not Inhibitory Synapses. eNeuro 2020; 7:ENEURO.0119-20.2020. [PMID: 32471847 PMCID: PMC7307634 DOI: 10.1523/eneuro.0119-20.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 04/17/2020] [Accepted: 04/26/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the success of antiretroviral therapy in suppressing viral load, nearly half of the 37 million people infected with HIV experience cognitive and motor impairments, collectively classified as HIV-associated neurocognitive disorders (HAND). In the CNS, HIV-infected microglia release neurotoxic agents that act indirectly to elicit excitotoxic synaptic injury. HIV trans-activator of transcription (Tat) protein is one such neurotoxin that is thought to play a major role in the neuropathogenesis of HAND. The endocannabinoid (eCB) system provides on-demand neuroprotection against excitotoxicity, and exogenous cannabinoids attenuate neurotoxicity in animal models of HAND. Whether this neuroprotective system is altered in the presence of HIV is unknown. Here, we examined the effects of Tat on the eCB system in rat primary hippocampal cultures. Using whole-cell patch-clamp electrophysiology, we measured changes in retrograde eCB signaling following exposure to Tat. Treatment with Tat significantly reduced the magnitude of depolarization-induced suppression of excitation (DSE) in a graded manner over the course of 48 h. Interestingly, Tat did not alter this form of short-term synaptic plasticity at inhibitory terminals. The Tat-induced decrease in eCB signaling resulted from impaired CB1 receptor (CB1R)-mediated presynaptic inhibition of glutamate release. This novel loss-of-function was particularly dramatic for low-efficacy agonists such as the eCB 2-arachidonoylglycerol (2-AG) and Δ9-tetrahydrocannabinol (Δ9-THC), the main psychoactive ingredient in marijuana. Our observation that HIV Tat decreases CB1R function in vitro suggests that eCB-mediated neuroprotection may be reduced in vivo; this effect of Tat may contribute to synaptodendritic injury in HAND.
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Affiliation(s)
- Mariah M Wu
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Stanley A Thayer
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455
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HIV-1 Tat protein attenuates the clinical course of experimental autoimmune encephalomyelitis (EAE). Int Immunopharmacol 2019; 78:105943. [PMID: 31830622 DOI: 10.1016/j.intimp.2019.105943] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 09/04/2019] [Accepted: 09/26/2019] [Indexed: 01/01/2023]
Abstract
A growing body of evidence has shown that the human immunodeficiency virus (HIV) infection is associated with a significantly decreased risk of developing multiple sclerosis (MS) in patients with acquired immunodeficiency virus (AIDS). It is thought that two mechanisms are in charge of protection against MS, which include immunosuppression induced by chronic HIV infection (depletion of CD4 + T cells) and antiretroviral medications. HIV-1 encodes several regulatory (Tat and Rev) and accessory (Vpr, Vif, Vpu, and Nef) proteins that have immunosuppressive and immunomodulatory properties. HIV-1 Tat protein is a strongly immunosuppressive agent and can cross the blood-brain barrier (BBB). In this study, we examined the effect of HIV-1 Tat, which is classified into clade B and C, on inflammation, gliosis, apoptosis, and behavioral function in a murine model of MS called experimental autoimmune encephalomyelitis (EAE). For this aim, mice were immunized with myelin oligodendrocyte glycoprotein 35-55 (MOG35-55), followed by pertussis toxin to induce paralysis in EAE mice. After the induction of EAE in mice, the animals intraperitoneally received serial doses of HIV-1 Tat clade B and C (5, 10, and 20 µg/kg body weight) when the early clinical manifestations of EAE were initiated. The results showed that the administration of both clades of the Tat protein led to a marked decrease in the clinical score of EAE mice, as well as improvement in motor-neuron functions. In line with this, Tat considerably reduced the number of apoptotic cells in the sacral region of the spinal cord through the upregulation expression of the Bcl-2 protein. Besides, proinflammatory cytokines such as, IFN-γ, TNF-α, IL-6, and IL-17 were significantly diminished in the serum and spinal cord of EAE mice receiving HIV-1 Tat clade B and C. Conversely, anti-inflammatory cytokines, including IL-10 and IL-4 were elevated in the serum and spinal cord of EAE mice receiving HIV Tat clade B and C when compared with the control group. The immunohistochemical analysis indicated that HIV-1 Tat clade B and C mitigated microgliosis and astrogliosis. The flow cytometry analysis demonstrated that the number of Th1 and Th17cells was significantly decreased in response to TAT administration while the frequency of Th2 cells was markedly increased in the peripheral blood of mice with EAE without influencing the number of T regulatory cells (CD4 + CD25 + forkhead box protein 3 + ). It seems that HIV-1 Tat could be a bona fide therapeutic protein for the alleviation of MS since it has beneficial roles in the suppression of neuroinflammation in MS pathology.
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Alvarez-Carbonell D, Ye F, Ramanath N, Garcia-Mesa Y, Knapp PE, Hauser KF, Karn J. Cross-talk between microglia and neurons regulates HIV latency. PLoS Pathog 2019; 15:e1008249. [PMID: 31887215 PMCID: PMC6953890 DOI: 10.1371/journal.ppat.1008249] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 01/10/2020] [Accepted: 12/01/2019] [Indexed: 12/30/2022] Open
Abstract
Despite effective antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) are found in nearly one-third of patients. Using a cellular co-culture system including neurons and human microglia infected with HIV (hμglia/HIV), we investigated the hypothesis that HIV-dependent neurological degeneration results from the periodic emergence of HIV from latency within microglial cells in response to neuronal damage or inflammatory signals. When a clonal hμglia/HIV population (HC69) expressing HIV, or HIV infected human primary and iPSC-derived microglial cells, were cultured for a short-term (24 h) with healthy neurons, HIV was silenced. The neuron-dependent induction of latency in HC69 cells was recapitulated using induced pluripotent stem cell (iPSC)-derived GABAergic cortical (iCort) and dopaminergic (iDopaNer), but not motor (iMotorNer), neurons. By contrast, damaged neurons induce HIV expression in latently infected microglial cells. After 48-72 h co-culture, low levels of HIV expression appear to damage neurons, which further enhances HIV expression. There was a marked reduction in intact dendrites staining for microtubule associated protein 2 (MAP2) in the neurons exposed to HIV-expressing microglial cells, indicating extensive dendritic pruning. To model neurotoxicity induced by methamphetamine (METH), we treated cells with nM levels of METH and suboptimal levels of poly (I:C), a TLR3 agonist that mimics the effects of the circulating bacterial rRNA found in HIV infected patients. This combination of agents potently induced HIV expression, with the METH effect mediated by the σ1 receptor (σ1R). In co-cultures of HC69 cells with iCort neurons, the combination of METH and poly(I:C) induced HIV expression and dendritic damage beyond levels seen using either agent alone, Thus, our results demonstrate that the cross-talk between healthy neurons and microglia modulates HIV expression, while HIV expression impairs this intrinsic molecular mechanism resulting in the excessive and uncontrolled stimulation of microglia-mediated neurotoxicity.
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Affiliation(s)
- David Alvarez-Carbonell
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Fengchun Ye
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Nirmala Ramanath
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Yoelvis Garcia-Mesa
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Pamela E. Knapp
- Departments of Pharmacology and Toxicology and Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States of America
| | - Kurt F. Hauser
- Departments of Pharmacology and Toxicology and Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States of America
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
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11
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SIV-Mediated Synaptic Dysfunction Is Associated with an Increase in Synapsin Site 1 Phosphorylation and Impaired PP2A Activity. J Neurosci 2019; 39:7006-7018. [PMID: 31270156 DOI: 10.1523/jneurosci.0178-19.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 05/31/2019] [Accepted: 06/22/2019] [Indexed: 11/21/2022] Open
Abstract
Although the reduction of viral loads in people with HIV undergoing combination antiretroviral therapy has mitigated AIDS-related symptoms, the prevalence of neurological impairments has remained unchanged. HIV-associated CNS dysfunction includes impairments in memory, attention, memory processing, and retrieval. Here, we show a significant site-specific increase in the phosphorylation of Syn I serine 9, site 1, in the frontal cortex lysates and synaptosome preparations of male rhesus macaques infected with simian immunodeficiency virus (SIV) but not in uninfected or SIV-infected antiretroviral therapy animals. Furthermore, we found that a lower protein phosphatase 2A (PP2A) activity, a phosphatase responsible for Syn I (S9) dephosphorylation, is primarily associated with the higher S9 phosphorylation in the frontal cortex of SIV-infected macaques. Comparison of brain sections confirmed higher Syn I (S9) in the frontal cortex and greater coexpression of Syn I and PP2A A subunit, which was observed as perinuclear aggregates in the somata of the frontal cortex of SIV-infected macaques. Synaptosomes from SIV-infected animals were physiologically tested using a synaptic vesicle endocytosis assay and FM4-64 dye showing a significantly higher baseline depolarization levels in synaptosomes of SIV+-infected than uninfected control or antiretroviral therapy animals. A PP2A-activating FDA-approved drug, FTY720, decreased the higher synaptosome depolarization in SIV-infected animals. Our results suggest that an impaired distribution and lower activity of serine/threonine phosphatases in the context of HIV infection may cause an indirect effect on the phosphorylation levels of essential proteins involving in synaptic transmission, supporting the occurrence of specific impairments in the synaptic activity during SIV infection.SIGNIFICANCE STATEMENT Even with antiretroviral therapy, neurocognitive deficits, including impairments in attention, memory processing, and retrieval, are still major concerns in people living with HIV. Here, we used the rhesus macaque simian immunodeficiency virus model with and without antiretroviral therapy to study the dynamics of phosphorylation of key amino acid residues of synapsin I, which critically impacts synaptic vesicle function. We found a significant increase in synapsin I phosphorylation at serine 9, which was driven by dysfunction of serine/threonine protein phosphatase 2A in the nerve terminals. Our results suggest that an impaired distribution and lower activity of serine/threonine phosphatases in the context of HIV infection may cause an indirect effect on the phosphorylation levels of essential proteins involved in synaptic transmission.
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12
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Bao D, Wang J, Liu J, Qin T, Liu H. The attenuation of HIV-1 Tat-induced neurotoxicity by Salvianic acid A and Danshen granule. Int J Biol Macromol 2018; 124:863-870. [PMID: 30503790 DOI: 10.1016/j.ijbiomac.2018.11.146] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 10/08/2018] [Accepted: 11/14/2018] [Indexed: 11/18/2022]
Abstract
The neurotoxicity of HIV-1 Tat protein contributes significantly to the pathogenesis of HAND, and hence the attractive therapeutic strategies focusing on Tat-induced neurotoxicity are warranted. Salvia miltiorrhiza have been known to antioxidant property and neuroprotective effects. The Danshen granule is the pharmaceutical dosage forms of Salvia miltiorrhiza and Salvianic acid A is an essential chemical constituent of Salvia miltiorrhiza. However, the protective effects of Salvianic acid A and Danshen granule on Tat-induced neurotoxicity remain unknown. Here, we found that Salvianic acid A and Danshen granule remarkable inhibited Tat-induced cell death, blocked LDH release and rescued dendritic spine loss. Furthermore, Salvianic acid A and Danshen granule significantly ameliorates Tat-induced intracellular ROS and MDA production, attenuates cell apoptosis. In addition, Salvianic acid A and Danshen granule pretreatment obviously increases antioxidant enzymatic activity of CAT, SOD and GSH-Px and inhibits apoptotic pathways. In conclusion, this study demonstrated that Salvianic acid A and Danshen granule provides substantial neuroprotection against Tat-induced neurotoxicity, which may be new therapeutic agent in Tat induced HAND or neurodegenerative diseases.
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Affiliation(s)
- Dengke Bao
- Henan Provincial People's Hospital, Henan University, Zhengzhou, Henan 450002, China; Laboratory of Cancer Biomarkers and Liquid Biopsy, Pharmaceutical College of Henan University, Kaifeng, Henan 475004, China
| | - Jingkai Wang
- Department of Nursing, Nanyang Medical College, Nan Yang, Henan 473000, China
| | - Junqi Liu
- Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 453000, China
| | - Tao Qin
- Henan Provincial People's Hospital, Henan University, Zhengzhou, Henan 450002, China.
| | - Hongliang Liu
- Laboratory of Cancer Biomarkers and Liquid Biopsy, Pharmaceutical College of Henan University, Kaifeng, Henan 475004, China.
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13
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Hammond JW, Qiu WQ, Marker DF, Chamberlain JM, Greaves-Tunnell W, Bellizzi MJ, Lu SM, Gelbard HA. HIV Tat causes synapse loss in a mouse model of HIV-associated neurocognitive disorder that is independent of the classical complement cascade component C1q. Glia 2018; 66:2563-2574. [PMID: 30325063 DOI: 10.1002/glia.23511] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 08/08/2018] [Accepted: 08/08/2018] [Indexed: 12/14/2022]
Abstract
Microglial activation, increased proinflammatory cytokine production, and a reduction in synaptic density are key pathological features associated with HIV-associated neurocognitive disorders (HAND). Even with combination antiretroviral therapy (cART), more than 50% of HIV-positive individuals experience some type of cognitive impairment. Although viral replication is inhibited by cART, HIV proteins such as Tat are still produced within the nervous system that are neurotoxic, involved in synapse elimination, and provoke enduring neuroinflammation. As complement deposition on synapses followed by microglial engulfment has been shown during normal development and disease to be a mechanism for pruning synapses, we have tested whether complement is required for the loss of synapses that occurs after a cortical Tat injection mouse model of HAND. In Tat-injected animals evaluated 7 or 28 days after injection, levels of early complement pathway components, C1q and C3, are significantly elevated and associated with microgliosis and a loss of synapses. However, C1qa knockout mice have the same level of Tat-induced synapse loss as wild-type (WT) mice, showing that the C1q-initiated classical complement cascade is not driving synapse removal during HIV1 Tat-induced neuroinflammation.
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Affiliation(s)
- Jennetta W Hammond
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York
| | - Wen Q Qiu
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York
| | - Daniel F Marker
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York
| | - Jeffrey M Chamberlain
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York
| | - Will Greaves-Tunnell
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York
| | - Matthew J Bellizzi
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York
| | - Shao-Ming Lu
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York
| | - Harris A Gelbard
- Center for Neurotherapeutics Discovery, University of Rochester Medical Center, Rochester, New York
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14
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Miller D, Shaerzadeh F, Phan L, Sharif N, Gamble-George J, McLaughlin J, Streit WJ, Khoshbouei H. HIV-1 Tat regulation of dopamine transmission and microglial reactivity is brain region specific. Glia 2018; 66:1915-1928. [PMID: 29733459 PMCID: PMC6185750 DOI: 10.1002/glia.23447] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/08/2018] [Accepted: 04/10/2018] [Indexed: 12/14/2022]
Abstract
The transactivator of transcription protein, HIV-1 Tat, is linked to neuroAIDS, where degeneration of dopamine neurons occurs. Using a mouse model expressing GFAP-driven Tat protein under doxycycline (Dox) regulation, we investigated microglial-neuronal interactions in the rostral substantia nigra pars compacta (SNc). Immunohistochemistry for microglia and tyrosine hydroxylase (TH) showed that the ratio of microglia to dopamine neurons is smaller in the SNc than in the ventral tegmental area (VTA) and that this difference is maintained following 7-day Dox exposure in wild type animals. Administration of Dox to wild types had no effect on microglial densities. In addressing the sensitivity of neurons to potentially adverse effects of HIV-1 Tat, we found that HIV-1 Tat exposure in vivo selectively decreased TH immunoreactivity in the SNc but not in the VTA, while levels of TH mRNA in the SNc remained unchanged. HIV-1 Tat induction in vivo did not alter the total number of neurons in these brain regions. Application of Tat (5 ng) into dopamine neurons with whole-cell patch pipette decreased spontaneous firing activity. Tat induction also produced a decline in microglial cell numbers, but no microglial activation. Thus, disappearance of dopaminergic phenotype is due to a loss of TH immunoreactivity rather than to neuronal death, which would have triggered microglial activation. We conclude that adverse effects of HIV-1 Tat produce a hypodopamine state by decreasing TH immunoreactivity and firing activity of dopamine neurons. Reduced microglial numbers after Tat exposure in vivo suggest impaired microglial functions and altered bidirectional interactions between dopamine neurons and microglia.
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Affiliation(s)
- Douglas Miller
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Fatemeh Shaerzadeh
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Leah Phan
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Nesrin Sharif
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Joyonna Gamble-George
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Jay McLaughlin
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL 32610
| | - Wolfgang J. Streit
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
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15
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Olson KE, Bade AN, Namminga KL, Potash MJ, Mosley RL, Poluektova LY, Volsky DJ, Gendelman HE. Persistent EcoHIV infection induces nigral degeneration in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-intoxicated mice. J Neurovirol 2018; 24:398-410. [PMID: 29594983 PMCID: PMC6105545 DOI: 10.1007/s13365-018-0629-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 03/01/2018] [Accepted: 03/02/2018] [Indexed: 02/07/2023]
Abstract
The widespread use of antiretroviral therapy for treatment of human immunodeficiency virus (HIV) infections has dramatically improved the quality and duration of life for HIV-positive individuals. Despite this success, HIV persists for the life of an infected person in tissue reservoirs including the nervous system. Thus, whether HIV exacerbates age-related brain disorders such as Parkinson's disease (PD) is of concern. In support of this idea, HIV infection can be associated with motor and gait abnormalities that parallel late-stage manifestations of PD including dopaminergic neuronal loss. With these findings in hand, we investigated whether viral infection could affect nigrostriatal degeneration or exacerbate chemically induced nigral degeneration. We now demonstrate an additive effect of EcoHIV on dopaminergic neuronal loss and neuroinflammation induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine intoxication. HIV-1-infected humanized mice failed to recapitulate these EcoHIV results suggesting species-specific neural signaling. The results demonstrate a previously undefined EcoHIV-associated neurodegenerative response that may be used to model pathobiological aspects of PD.
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Affiliation(s)
- Katherine E Olson
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Aditya N Bade
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Krista L Namminga
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Mary Jane Potash
- Department of Medicine, Infectious Diseases Division, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - R Lee Mosley
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Larisa Y Poluektova
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - David J Volsky
- Department of Medicine, Infectious Diseases Division, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Howard E Gendelman
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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16
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HIV-1 Protein Tat 1-72 Impairs Neuronal Dendrites via Activation of PP1 and Regulation of the CREB/BDNF Pathway. Virol Sin 2018; 33:261-269. [PMID: 29737506 DOI: 10.1007/s12250-018-0031-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/02/2018] [Indexed: 12/18/2022] Open
Abstract
Despite the success of combined antiretroviral therapy in recent years, the prevalence of human immunodeficiency virus (HIV)-associated neurocognitive disorders in people living with HIV-1 is increasing, significantly reducing the health-related quality of their lives. Although neurons cannot be infected by HIV-1, shed viral proteins such as transactivator of transcription (Tat) can cause dendritic damage. However, the detailed molecular mechanism of Tat-induced neuronal impairment remains unknown. In this study, we first showed that recombinant Tat (1-72 aa) induced neurotoxicity in primary cultured mouse neurons. Second, exposure to Tat1-72 was shown to reduce the length and number of dendrites in cultured neurons. Third, Tat1-72 (0-6 h) modulates protein phosphatase 1 (PP1) expression and enhances its activity by decreasing the phosphorylation level of PP1 at Thr320. Finally, Tat1-72 (24 h) downregulates CREB activity and CREB-mediated gene (BDNF, c-fos, Egr-1) expression. Together, these findings suggest that Tat1-72 might impair cognitive function by regulating the activity of PP1 and the CREB/BDNF pathway.
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17
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Abstract
A defining feature of HIV-associated neurocognitive disorder (HAND) is the loss of excitatory synaptic connections. Synaptic changes that occur during exposure to HIV appear to result, in part, from a homeostatic scaling response. Here we discuss the mechanisms of these changes from the perspective that they might be part of a coping mechanism that reduces synapses to prevent excitotoxicity. In transgenic animals expressing the HIV proteins Tat or gp120, the loss of synaptic markers precedes changes in neuronal number. In vitro studies have shown that HIV-induced synapse loss and cell death are mediated by distinct mechanisms. Both in vitro and animal studies suggest that HIV-induced synaptic scaling engages new mechanisms that suppress network connectivity and that these processes might be amenable to therapeutic intervention. Indeed, pharmacological reversal of synapse loss induced by HIV Tat restores cognitive function. In summary, studies indicate that there are temporal, mechanistic and pharmacological features of HIV-induced synapse loss that are consistent with homeostatic plasticity. The increasingly well delineated signaling mechanisms that regulate synaptic scaling may reveal pharmacological targets suitable for normalizing synaptic function in chronic neuroinflammatory states such as HAND.
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Affiliation(s)
- Matthew V Green
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Jonathan D Raybuck
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Xinwen Zhang
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Mariah M Wu
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Stanley A Thayer
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
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18
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Zeinolabediny Y, Caccuri F, Colombo L, Morelli F, Romeo M, Rossi A, Schiarea S, Ciaramelli C, Airoldi C, Weston R, Donghui L, Krupinski J, Corpas R, García-Lara E, Sarroca S, Sanfeliu C, Slevin M, Caruso A, Salmona M, Diomede L. HIV-1 matrix protein p17 misfolding forms toxic amyloidogenic assemblies that induce neurocognitive disorders. Sci Rep 2017; 7:10313. [PMID: 28871125 PMCID: PMC5583282 DOI: 10.1038/s41598-017-10875-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 08/16/2017] [Indexed: 12/26/2022] Open
Abstract
Human immunodeficiency virus type-1 (HIV-1)-associated neurocognitive disorder (HAND) remains an important neurological manifestation that adversely affects a patient’s quality of life. HIV-1 matrix protein p17 (p17) has been detected in autoptic brain tissue of HAND individuals who presented early with severe AIDS encephalopathy. We hypothesised that the ability of p17 to misfold may result in the generation of toxic assemblies in the brain and may be relevant for HAND pathogenesis. A multidisciplinary integrated approach has been applied to determine the ability of p17 to form soluble amyloidogenic assemblies in vitro. To provide new information into the potential pathogenic role of soluble p17 species in HAND, their toxicological capability was evaluated in vivo. In C. elegans, capable of recognising toxic assemblies of amyloidogenic proteins, p17 induces a specific toxic effect which can be counteracted by tetracyclines, drugs able to hinder the formation of large oligomers and consequently amyloid fibrils. The intrahippocampal injection of p17 in mice reduces their cognitive function and induces behavioral deficiencies. These findings offer a new way of thinking about the possible cause of neurodegeneration in HIV-1-seropositive patients, which engages the ability of p17 to form soluble toxic assemblies.
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Affiliation(s)
- Yasmin Zeinolabediny
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Francesca Caccuri
- Department of Molecular and Translational Medicine, University of Brescia, Piazza del Mercato 15, 25121, Brescia, Italy
| | - Laura Colombo
- Department of Molecular Biochemistry and Pharmacology, IRCCS- Istituto di Ricerche Farmacologiche "Mario Negri", Via G. La Masa 19, 20156, Milano, Italy
| | - Federica Morelli
- Department of Molecular Biochemistry and Pharmacology, IRCCS- Istituto di Ricerche Farmacologiche "Mario Negri", Via G. La Masa 19, 20156, Milano, Italy
| | - Margherita Romeo
- Department of Molecular Biochemistry and Pharmacology, IRCCS- Istituto di Ricerche Farmacologiche "Mario Negri", Via G. La Masa 19, 20156, Milano, Italy
| | - Alessandro Rossi
- Department of Molecular Biochemistry and Pharmacology, IRCCS- Istituto di Ricerche Farmacologiche "Mario Negri", Via G. La Masa 19, 20156, Milano, Italy
| | - Silvia Schiarea
- Department of Environmental Health Sciences, IRCCS- Istituto di Ricerche Farmacologiche "Mario Negri", Via G. La Masa 19, 20156, Milano, Italy
| | - Carlotta Ciaramelli
- Department of Biotechnologies and Biosciences, University of Milano Bicocca, Piazza dell'Ateneo Nuovo 1, 20126, Milano, Italy
| | - Cristina Airoldi
- Department of Biotechnologies and Biosciences, University of Milano Bicocca, Piazza dell'Ateneo Nuovo 1, 20126, Milano, Italy
| | - Ria Weston
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Liu Donghui
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Jerzy Krupinski
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK.,Hospital Universitari Mútua de Terrassa, Department of Neurology, Terrassa, Barcelona, Spain
| | - Rubén Corpas
- Institut d'Investigaciones Biomèdiques de Barcelona, CSIC and IDIBAPS, Barcelona, Spain
| | - Elisa García-Lara
- Institut d'Investigaciones Biomèdiques de Barcelona, CSIC and IDIBAPS, Barcelona, Spain.,University of Medicine and Pharmacy, Targu Mures, Romania
| | - Sara Sarroca
- Institut d'Investigaciones Biomèdiques de Barcelona, CSIC and IDIBAPS, Barcelona, Spain
| | - Coral Sanfeliu
- Institut d'Investigaciones Biomèdiques de Barcelona, CSIC and IDIBAPS, Barcelona, Spain
| | - Mark Slevin
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK.,University of Medicine and Pharmacy, Targu Mures, Romania.,Department of Pathology/Medicine, Griffith University, Brisbane, Australia
| | - Arnaldo Caruso
- Department of Molecular and Translational Medicine, University of Brescia, Piazza del Mercato 15, 25121, Brescia, Italy
| | - Mario Salmona
- Department of Molecular Biochemistry and Pharmacology, IRCCS- Istituto di Ricerche Farmacologiche "Mario Negri", Via G. La Masa 19, 20156, Milano, Italy
| | - Luisa Diomede
- Department of Molecular Biochemistry and Pharmacology, IRCCS- Istituto di Ricerche Farmacologiche "Mario Negri", Via G. La Masa 19, 20156, Milano, Italy.
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19
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Scutari R, Alteri C, Perno CF, Svicher V, Aquaro S. The Role of HIV Infection in Neurologic Injury. Brain Sci 2017; 7:E38. [PMID: 28383502 PMCID: PMC5406695 DOI: 10.3390/brainsci7040038] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/27/2017] [Accepted: 03/30/2017] [Indexed: 12/20/2022] Open
Abstract
The central nervous system (CNS) is a very challenging HIV-1 sanctuary, in which HIV-1 replication is established early on during acute infection and can persist despite potent antiretroviral treatments. HIV-1 infected macrophages play a pivotal role acting as vehicles for HIV-1 to spread into the brain, and can be the major contributor of an early compartmentalization. HIV-1 infection in CNS may lead to a broad spectrum of neurological syndromes, such as dementia, mild neurocognitive disorders, and asymptomatic impairment. These clinical manifestations are caused by the release of neurotoxins from infected cells (mainly macrophages), and also by several HIV-1 proteins, able to activate cell-signaling involved in the control of cellular survival and apoptosis. This review is aimed at highlighting the virological aspects associated with the onset of neurocognitive disorders and at addressing the novel therapeutic approaches to stop HIV-1 replication in this critical sanctuary.
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Affiliation(s)
- Rossana Scutari
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome 00133, Italy.
| | - Claudia Alteri
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome 00133, Italy.
| | - Carlo Federico Perno
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome 00133, Italy.
| | - Valentina Svicher
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome 00133, Italy.
| | - Stefano Aquaro
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS) 87036, Italy.
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20
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Carroll A, Brew B. HIV-associated neurocognitive disorders: recent advances in pathogenesis, biomarkers, and treatment. F1000Res 2017; 6:312. [PMID: 28413625 PMCID: PMC5365228 DOI: 10.12688/f1000research.10651.1] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/22/2017] [Indexed: 12/21/2022] Open
Abstract
HIV-associated neurocognitive disorders (HAND) remain prevalent despite plasma viral suppression by antiretroviral agents. In fact, the prevalence of milder subtypes of cognitive impairment is increasing. Neuropsychologic testing remains the "gold standard" of diagnosis; however, this is time consuming and costly in a resource-poor environment. Recently developed screening tools, such as CogState and the revised HIV dementia scale, have very good sensitivity and specificity in the more severe stages of HAND. However, questions remain regarding the utility of, optimal population for, and insensitivity of tests in mild HAND. Recognition of ongoing viral persistence and the inflammatory milieu in the central nervous system (CNS) has advanced our understanding of the pathogenesis of HAND and facilitated the development of biomarkers of CNS disease. The importance of the monocyte-macrophage lineage cell and the astrocyte as viral reservoirs, HIV viral proteins, self-perpetuating CNS inflammation, and CCR5 chemokine receptor neurotropism has been identified. Whilst biomarkers demonstrate monocyte activation, inflammation, and neuronal injury, they remain limited in their clinical utility. The improved understanding of pathogenic mechanisms has led to novel approaches to the treatment of HAND; however, despite these advances, the optimal management is still undefined.
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Affiliation(s)
- Antonia Carroll
- Department of Neurology, St Vincent’s Hospital, Level 4, Xavier Building, Victoria Street, Darlinghurst, Sydney, Australia
- University of New South Wales, St. Vincent’s Clinical School, Delacy Building, Victoria Street, Darlinghurst, Sydney, Australia
| | - Bruce Brew
- Department of Neurology, St Vincent’s Hospital, Level 4, Xavier Building, Victoria Street, Darlinghurst, Sydney, Australia
- Peter Duncan Neurosciences Unit, St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Sydney, Australia
- Department of HIV Medicine, St Vincent’s Hospital, Level 4, Xavier Building, Victoria Street, Darlinghurst, Sydney, Australia
- University of New South Wales, St. Vincent’s Clinical School, Delacy Building, Victoria Street, Darlinghurst, Sydney, Australia
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21
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Destination Brain: the Past, Present, and Future of Therapeutic Gene Delivery. J Neuroimmune Pharmacol 2017; 12:51-83. [PMID: 28160121 DOI: 10.1007/s11481-016-9724-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 12/12/2016] [Indexed: 12/20/2022]
Abstract
Neurological diseases and disorders (NDDs) present a significant societal burden and currently available drug- and biological-based therapeutic strategies have proven inadequate to alleviate it. Gene therapy is a suitable alternative to treat NDDs compared to conventional systems since it can be tailored to specifically alter select gene expression, reverse disease phenotype and restore normal function. The scope of gene therapy has broadened over the years with the advent of RNA interference and genome editing technologies. Consequently, encouraging results from central nervous system (CNS)-targeted gene delivery studies have led to their transition from preclinical to clinical trials. As we shift to an exciting gene therapy era, a retrospective of available literature on CNS-associated gene delivery is in order. This review is timely in this regard, since it analyzes key challenges and major findings from the last two decades and evaluates future prospects of brain gene delivery. We emphasize major areas consisting of physiological and pharmacological challenges in gene therapy, function-based selection of a ideal cellular target(s), available therapy modalities, and diversity of viral vectors and nanoparticles as vehicle systems. Further, we present plausible answers to key questions such as strategies to circumvent low blood-brain barrier permeability and most suitable CNS cell types for targeting. We compare and contrast pros and cons of the tested viral vectors in the context of delivery systems used in past and current clinical trials. Gene vector design challenges are also evaluated in the context of cell-specific promoters. Key challenges and findings reported for recent gene therapy clinical trials, assessing viral vectors and nanoparticles are discussed from the perspective of bench to bedside gene therapy translation. We conclude this review by tying together gene delivery challenges, available vehicle systems and comprehensive analyses of neuropathogenesis to outline future prospects of CNS-targeted gene therapies.
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Bisht K, Sharma KP, Lecours C, Sánchez MG, El Hajj H, Milior G, Olmos-Alonso A, Gómez-Nicola D, Luheshi G, Vallières L, Branchi I, Maggi L, Limatola C, Butovsky O, Tremblay MÈ. Dark microglia: A new phenotype predominantly associated with pathological states. Glia 2016; 64:826-39. [PMID: 26847266 PMCID: PMC4949554 DOI: 10.1002/glia.22966] [Citation(s) in RCA: 274] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/06/2015] [Accepted: 12/28/2015] [Indexed: 12/24/2022]
Abstract
The past decade has witnessed a revolution in our understanding of microglia. These immune cells were shown to actively remodel neuronal circuits, leading to propose new pathogenic mechanisms. To study microglial implication in the loss of synapses, the best pathological correlate of cognitive decline across chronic stress, aging, and diseases, we recently conducted ultrastructural analyses. Our work uncovered the existence of a new microglial phenotype that is rarely present under steady state conditions, in hippocampus, cerebral cortex, amygdala, and hypothalamus, but becomes abundant during chronic stress, aging, fractalkine signaling deficiency (CX3 CR1 knockout mice), and Alzheimer's disease pathology (APP-PS1 mice). Even though these cells display ultrastructural features of microglia, they are strikingly distinct from the other phenotypes described so far at the ultrastructural level. They exhibit several signs of oxidative stress, including a condensed, electron-dense cytoplasm and nucleoplasm making them as "dark" as mitochondria, accompanied by a pronounced remodeling of their nuclear chromatin. Dark microglia appear to be much more active than the normal microglia, reaching for synaptic clefts, while extensively encircling axon terminals and dendritic spines with their highly ramified and thin processes. They stain for the myeloid cell markers IBA1 and GFP (in CX3 CR1-GFP mice), and strongly express CD11b and microglia-specific 4D4 in their processes encircling synaptic elements, and TREM2 when they associate with amyloid plaques. Overall, these findings suggest that dark microglia, a new phenotype that we identified based on their unique properties, could play a significant role in the pathological remodeling of neuronal circuits, especially at synapses.
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Affiliation(s)
- Kanchan Bisht
- Axe Neurosciences, Centre De Recherche Du CHU De Québec, Québec, Québec, Canada
| | - Kaushik P Sharma
- Axe Neurosciences, Centre De Recherche Du CHU De Québec, Québec, Québec, Canada
| | - Cynthia Lecours
- Axe Neurosciences, Centre De Recherche Du CHU De Québec, Québec, Québec, Canada
| | | | - Hassan El Hajj
- Axe Neurosciences, Centre De Recherche Du CHU De Québec, Québec, Québec, Canada
| | - Giampaolo Milior
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Adrián Olmos-Alonso
- Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Diego Gómez-Nicola
- Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Giamal Luheshi
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Québec, Canada
| | - Luc Vallières
- Axe Neurosciences, Centre De Recherche Du CHU De Québec, Québec, Québec, Canada
| | - Igor Branchi
- Section of Behavioural Neurosciences, Department of Cell Biology and Neurosciences, Istituto Superiore Di Sanità, Rome, Italy
| | - Laura Maggi
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Cristina Limatola
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre De Recherche Du CHU De Québec, Québec, Québec, Canada
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Kern JK, Geier DA, Sykes LK, Geier MR. Relevance of Neuroinflammation and Encephalitis in Autism. Front Cell Neurosci 2016; 9:519. [PMID: 26834565 PMCID: PMC4717322 DOI: 10.3389/fncel.2015.00519] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 12/24/2015] [Indexed: 12/12/2022] Open
Abstract
In recent years, many studies indicate that children with an autism spectrum disorder (ASD) diagnosis have brain pathology suggestive of ongoing neuroinflammation or encephalitis in different regions of their brains. Evidence of neuroinflammation or encephalitis in ASD includes: microglial and astrocytic activation, a unique and elevated proinflammatory profile of cytokines, and aberrant expression of nuclear factor kappa-light-chain-enhancer of activated B cells. A conservative estimate based on the research suggests that at least 69% of individuals with an ASD diagnosis have microglial activation or neuroinflammation. Encephalitis, which is defined as inflammation of the brain, is medical diagnosis code G04.90 in the International Classification of Disease, 10th revision; however, children with an ASD diagnosis are not generally assessed for a possible medical diagnosis of encephalitis. This is unfortunate because if a child with ASD has neuroinflammation, then treating the underlying brain inflammation could lead to improved outcomes. The purpose of this review of the literature is to examine the evidence of neuroinflammation/encephalitis in those with an ASD diagnosis and to address how a medical diagnosis of encephalitis, when appropriate, could benefit these children by driving more immediate and targeted treatments.
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Affiliation(s)
- Janet K. Kern
- Institute of Chronic Illnesses, Inc., Silver SpringMD, USA
| | - David A. Geier
- Institute of Chronic Illnesses, Inc., Silver SpringMD, USA
| | | | - Mark R. Geier
- Institute of Chronic Illnesses, Inc., Silver SpringMD, USA
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Levine AJ, Soontornniyomkij V, Achim CL, Masliah E, Gelman BB, Sinsheimer JS, Singer EJ, Moore DJ. Multilevel analysis of neuropathogenesis of neurocognitive impairment in HIV. J Neurovirol 2015; 22:431-41. [PMID: 26637429 DOI: 10.1007/s13365-015-0410-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/13/2015] [Accepted: 11/19/2015] [Indexed: 12/31/2022]
Abstract
The neuropathogenesis of HIV-associated neurocognitive disorders (HAND) remains puzzling. We interrogated several levels of data (host genetic, histopathology, brain viral load, and neurocognitive) to identify histopathological changes most relevant to HAND. The design of the study is a clinicopathological study employing genetic association analyses. Data and brain tissue from 80 HIV-infected adults were used. Markers in monocyte chemoattractant protein-1 (MCP-1), interleukin 1-alpha (IL1-α), macrophage inflammatory protein 1-alpha (MIP1-α), DRD3, DRD2, and apolipoprotein E (ApoE) were genotyped. Microtubule associated protein 2 (MAP2), synaptophysin (SYP), human leukocyte antigen-DR (HLA-DR), glial fibrillary acidic protein (GFAP), amyloid beta (A-Beta), and ionized calcium-binding adaptor molecule-1 (Iba-1) immunoreactivity were quantified in the frontal cortex, putamen, and hippocampus. A composite score for each marker (mean of the three brain regions) was used. Neurocognitive functioning and other clinical variables were determined within 1 year of death. Brain HIV RNA viral load was available for a subset of cases. MAP2 and SYP proved most relevant to neurocognitive functioning. Immunoreactivity of these markers, as well as A-Beta and Iba-1, was correlated with brain HIV RNA viral load. Several genetic markers in combination with other factors predicted histopathology: HIV blood viral load, MIP1-α genotype, and DRD3 genotype predicted Iba-1 immunoreactivity; the duration of infection and IL1-α genotype predicted GFAP immunoreactivity; ApoE genotype and age at death predicted A-Beta immunoreactivity. These data indicate that HIV replication in the brain is the primary driving force leading to neuroinflammation and dysfunctional protein clearance, as reflected by A-Beta and Iba-1. Downstream to these changes are synaptodendritic degeneration, which is the immediate histopathological substrate of the neurocognitive impairment characteristic of HAND. These intermediate histopathological phenotypes are influenced by host genetic polymorphisms in genes encoding cytokines/chemokines, neuronal protein clearance pathways, and dopaminergic factors.
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Affiliation(s)
- Andrew J Levine
- Department of Neurology, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA, USA.
| | | | - Cristian L Achim
- Departments of Psychiatry and Pathology, University of California San Diego School of Medicine, La Jolla, CA, USA
| | - Eliezer Masliah
- Departments of Neurosciences and Pathology, University of California San Diego School of Medicine, La Jolla, CA, USA
| | - Benjamin B Gelman
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Janet S Sinsheimer
- Departments of Human Genetics and Biomathematics, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA, USA
| | - Elyse J Singer
- Department of Neurology, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA, USA
| | - David J Moore
- Department of Psychiatry, University of California San Diego School of Medicine, La Jolla, CA, USA
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Wei J, Zhang Y, Knapp PE, Zhao T. HIV-1 Tat regulates the expression of the dcw operon and stimulates the proliferation of bacteria. Microb Pathog 2015; 90:34-40. [PMID: 26596708 DOI: 10.1016/j.micpath.2015.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 09/04/2015] [Accepted: 11/12/2015] [Indexed: 11/24/2022]
Abstract
Infections of pathogenic bacteria are very common in acquired immunodeficiency syndrome (AIDS) patients. However, the biological effects of HIV-1 Tat on bacteria are incompletely understood. In this study, HIV-1 Tat was expressed in Escherichia coli and Pseudomonas aeruginosa (PA01) to investigate its biological effects on bacteria. Bacterial cells expressing either HIV-1 Tat1-86 (Tat1-86) or HIV-1 Tat1-72 (Tat1-72) grow significantly faster than those with either only an empty vector or an unrelated control (GFP or Rluc). Supplementation of purified HIV-1 Tat1-86 or Tat1-101 protein into bacterial culture medium stimulated the growth of both E. coli and PA01. The expression profile of certain cell division-associated genes, such as those in the division cell wall (dcw) operon (ftsA, ftsQ, ftsW and ftsZ), yafO and zipA, was altered in HIV-1 Tat1-86 expressing E. coli BL21(DE3). Furthermore, the expression of firefly luciferase (Fluc) reporter gene, when engineered for control by the dcw promoter and terminator, was enhanced by HIV-1 Tat in E. coli, confirming that HIV-1 Tat transcriptionally regulates the expression of the dcw operon. The finding that HIV-1 Tat stimulates bacterial growth whether it is produced intracellularly or applied extracellularly may have relevance for HIV patients who are highly susceptible to opportunistic bacterial infections. Contents category: Viruses -Retroviruses. The GenBank accession number for the sequence of HIV-1 Tat1-86 is AF324439.1.
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Affiliation(s)
- Jinsong Wei
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China
| | - Yumin Zhang
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China
| | - Pamela E Knapp
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Tianyong Zhao
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China.
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Kelly EA, Russo AS, Jackson CD, Lamantia CE, Majewska AK. Proteolytic regulation of synaptic plasticity in the mouse primary visual cortex: analysis of matrix metalloproteinase 9 deficient mice. Front Cell Neurosci 2015; 9:369. [PMID: 26441540 PMCID: PMC4585116 DOI: 10.3389/fncel.2015.00369] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 09/04/2015] [Indexed: 01/16/2023] Open
Abstract
The extracellular matrix (ECM) is known to play important roles in regulating neuronal recovery from injury. The ECM can also impact physiological synaptic plasticity, although this process is less well understood. To understand the impact of the ECM on synaptic function and remodeling in vivo, we examined ECM composition and proteolysis in a well-established model of experience-dependent plasticity in the visual cortex. We describe a rapid change in ECM protein composition during Ocular Dominance Plasticity (ODP) in adolescent mice, and a loss of ECM remodeling in mice that lack the extracellular protease, matrix metalloproteinase-9 (MMP9). Loss of MMP9 also attenuated functional ODP following monocular deprivation (MD) and reduced excitatory synapse density and spine density in sensory cortex. While we observed no change in the morphology of existing dendritic spines, spine dynamics were altered, and MMP9 knock-out (KO) mice showed increased turnover of dendritic spines over a period of 2 days. We also analyzed the effects of MMP9 loss on microglia, as these cells are involved in extracellular remodeling and have been recently shown to be important for synaptic plasticity. MMP9 KO mice exhibited very limited changes in microglial morphology. Ultrastructural analysis, however, showed that the extracellular space surrounding microglia was increased, with concomitant increases in microglial inclusions, suggesting possible changes in microglial function in the absence of MMP9. Taken together, our results show that MMP9 contributes to ECM degradation, synaptic dynamics and sensory-evoked plasticity in the mouse visual cortex.
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Affiliation(s)
- Emily A Kelly
- Center for Visual Science, School of Medicine and Dentistry, Department of Neurobiology and Anatomy, University of Rochester Rochester, NY, USA
| | - Amanda S Russo
- Center for Visual Science, School of Medicine and Dentistry, Department of Neurobiology and Anatomy, University of Rochester Rochester, NY, USA
| | - Cory D Jackson
- Center for Visual Science, School of Medicine and Dentistry, Department of Neurobiology and Anatomy, University of Rochester Rochester, NY, USA
| | - Cassandra E Lamantia
- Center for Visual Science, School of Medicine and Dentistry, Department of Neurobiology and Anatomy, University of Rochester Rochester, NY, USA
| | - Ania K Majewska
- Center for Visual Science, School of Medicine and Dentistry, Department of Neurobiology and Anatomy, University of Rochester Rochester, NY, USA
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27
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Lee DE, Yue X, Ibrahim WG, Lentz MR, Peterson KL, Jagoda EM, Kassiou M, Maric D, Reid WC, Hammoud DA. Lack of neuroinflammation in the HIV-1 transgenic rat: an [(18)F]-DPA714 PET imaging study. J Neuroinflammation 2015; 12:171. [PMID: 26377670 PMCID: PMC4574011 DOI: 10.1186/s12974-015-0390-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 09/02/2015] [Indexed: 11/29/2022] Open
Abstract
Background HIV-associated neuroinflammation is believed to be a major contributing factor in the development of HIV-associated neurocognitive disorders (HAND). In this study, we used micropositron emission tomography (PET) imaging to quantify neuroinflammation in HIV-1 transgenic rat (Tg), a small animal model of HIV, known to develop neurological and behavioral problems. Methods Dynamic [18F]DPA-714 PET imaging was performed in Tg and age-matched wild-type (WT) rats in three age groups: 3-, 9-, and 16-month-old animals. As a positive control for neuroinflammation, we performed unilateral intrastriatal injection of quinolinic acid (QA) in a separate group of WT rats. To confirm our findings, we performed multiplex immunofluorescent staining for Iba1 and we measured cytokine/chemokine levels in brain lysates of Tg and WT rats at different ages. Results [18F]DPA-714 uptake in HIV-1 Tg rat brains was generally higher than in age-matched WT rats but this was not statistically significant in any age group. [18F]DPA-714 uptake in the QA-lesioned rats was significantly higher ipsilateral to the lesion compared to contralateral side indicating neuroinflammatory changes. Iba1 immunofluorescence showed no significant differences in microglial activation between the Tg and WT rats, while the QA-lesioned rats showed significant activation. Finally, cytokine/chemokine levels in brain lysates of the Tg rats and WT rats were not significantly different. Conclusion Microglial activation might not be the primary mechanism for neuropathology in the HIV-1 Tg rats. Although [18F]DPA-714 is a good biomarker of neuroinflammation, it cannot be reliably used as an in vivo biomarker of neurodegeneration in the HIV-1 Tg rat. Electronic supplementary material The online version of this article (doi:10.1186/s12974-015-0390-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dianne E Lee
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, National Institutes of Health/Clinical Center, 10 Center Drive, Room 1C368, Bethesda, MD, 20814-9692, USA
| | - Xuyi Yue
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Wael G Ibrahim
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, National Institutes of Health/Clinical Center, 10 Center Drive, Room 1C368, Bethesda, MD, 20814-9692, USA
| | - Margaret R Lentz
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, National Institutes of Health/Clinical Center, 10 Center Drive, Room 1C368, Bethesda, MD, 20814-9692, USA
| | - Kristin L Peterson
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, National Institutes of Health/Clinical Center, 10 Center Drive, Room 1C368, Bethesda, MD, 20814-9692, USA
| | - Elaine M Jagoda
- Molecular Imaging Program (MIP), National Cancer Institute (NCI), Bethesda, MD, USA
| | - Michael Kassiou
- Chemistry Department, The University of Sydney, Sydney, Australia
| | - Dragan Maric
- Division of Intermural Research (DIR), National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD, USA
| | - William C Reid
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, National Institutes of Health/Clinical Center, 10 Center Drive, Room 1C368, Bethesda, MD, 20814-9692, USA
| | - Dima A Hammoud
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, National Institutes of Health/Clinical Center, 10 Center Drive, Room 1C368, Bethesda, MD, 20814-9692, USA.
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Leucine-rich repeat kinase 2 modulates neuroinflammation and neurotoxicity in models of human immunodeficiency virus 1-associated neurocognitive disorders. J Neurosci 2015; 35:5271-83. [PMID: 25834052 DOI: 10.1523/jneurosci.0650-14.2015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is the single most common genetic cause of both familial and sporadic Parkinson's disease (PD), both of which share pathogenetic and neurologic similarities with human immunodeficiency virus 1 (HIV-1)-associated neurocognitive disorders (HAND). Pathologic LRRK2 activity may also contribute to neuroinflammation, because microglia lacking LRRK2 exposed to proinflammatory stimuli have attenuated responses. Because microglial activation is a hallmark of HIV-1 neuropathology, we have investigated the role of LRRK2 activation using in vitro and in vivo models of HAND. We hypothesize that LRRK2 is a key modulator of microglial inflammatory responses, which play a pathogenic role in both HAND and PD, and that these responses may cause or exacerbate neuronal damage in these diseases. The HIV-1 Tat protein is a potent neurotoxin produced during HAND that induces activation of primary microglia in culture and long-lasting neuroinflammation and neurotoxicity when injected into the CNS of mice. We found that LRRK2 inhibition attenuates Tat-induced pS935-LRRK2 expression, proinflammatory cytokine and chemokine expression, and phosphorylated p38 and Jun N-terminal kinase signaling in primary microglia. In our murine model, cortical Tat injection in LRRK2 knock-out (KO) mice results in significantly diminished neuronal damage, as assessed by microtubule-associated protein 2 (MAP2), class III β-tubulin TUJ1, synapsin-1, VGluT, and cleaved caspase-3 immunostaining. Furthermore, Tat-injected LRRK2 KO animals have decreased infiltration of peripheral neutrophils, and the morphology of microglia from these mice were similar to that of vehicle-injected controls. We conclude that pathologic activation of LRRK2 regulates a significant component of the neuroinflammation associated with HAND.
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Paris JJ, Singh HD, Carey AN, McLaughlin JP. Exposure to HIV-1 Tat in brain impairs sensorimotor gating and activates microglia in limbic and extralimbic brain regions of male mice. Behav Brain Res 2015; 291:209-218. [PMID: 26005128 DOI: 10.1016/j.bbr.2015.05.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 05/07/2015] [Accepted: 05/13/2015] [Indexed: 12/27/2022]
Abstract
Human immunodeficiency virus (HIV) infection is associated with mood disorders and behavioral disinhibition. Impairments in sensorimotor gating and associated neurocognitive disorders are reported, but the HIV-proteins and mechanisms involved are not known. The regulatory HIV-1 protein, Tat, is neurotoxic and its expression in animal models increases anxiety-like behavior concurrent with neuroinflammation and structural changes in limbic and extra-limbic brain regions. We hypothesized that conditional expression of HIV-1 Tat1-86 in the GT-tg bigenic mouse model would impair sensorimotor gating and increase microglial reactivity in limbic and extralimbic brain regions. Conditional Tat induction via doxycycline (Dox) treatment (0-125 mg/kg, i.p., for 1-14 days) significantly potentiated the acoustic startle reflex (ASR) of GT-tg mice and impaired prepulse inhibition (PPI) of this response in a dose-dependent manner when Dox (100mg/kg) was administered for brief (1 day) or prolonged (daily for 7 days) intervals. A greater proportion of active/reactive Iba1-labeled microglia was seen in the anterior cingulate cortex (ACC), dentate gyrus, and nucleus accumbens core when Tat protein was induced under either brief or prolonged expression conditions. Other subregions of the medial prefrontal cortex, amygdala, hippocampal formation, ventral tegmental area, and ventral pallidum also displayed Tat-induced microglial activation, but only the activation observed in the ACC recapitulated the pattern of ASR and PPI behaviors. Tat exposure also increased frontal cortex GFAP. Pretreatment with indomethacin attenuated the behavioral effects of brief (but not prolonged) Tat-exposure. Overall, exposure to HIV-1 Tat protein induced sensorimotor deficits associated with acute and persistent neuroinflammation in limbic/extralimbic brain regions.
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Affiliation(s)
- Jason J Paris
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, FL 34987, USA
| | - Harminder D Singh
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, FL 34987, USA
| | - Amanda N Carey
- Northeastern University, Department of Psychology, Boston, MA 02115, USA
| | - Jay P McLaughlin
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, FL 34987, USA; Northeastern University, Department of Psychology, Boston, MA 02115, USA.
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30
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Abstract
OBJECTIVE Determine whether HIV and combination antiretroviral therapy (cART) affect resting-state functional connectivity (rs-fc) between the striatum and the cortical regions. METHODS Forty-nine HIV-uninfected (HIV-) and 132 HIV-infected (HIV+) (65% receiving cART) patients underwent laboratory studies (current and nadir CD4 T-cell counts, and plasma HIV viral load), neuropsychological performance testing, and neuroimaging. Rs-fc, which examines the coordination of neural activity in distant brain regions, was used to investigate the cortico-striatal functional connections. The effect of cART was assessed comparing HIV+ individuals on cART (HIV+/cART+), and HIV+ individuals not currently receiving cART (HIV+/cART-). Relationships between laboratory tests, cognitive performance, and cART on subcortical-cortical rs-fc were assessed by an analysis of variance. RESULTS HIV+ individuals had lower cortico-striatal functional connectivity than HIV- controls, specifically between the striatum and the default mode network (P < 0.001) and ventral attention network (P < 0.001). HIV+/cART+ individuals had higher functional connectivity between the striatum, and default mode network (P = 0.02) and ventral attention network (P = 0.01), compared to the HIV+/cART- patients. Laboratory (current and nadir CD4 T-cell counts, plasma viral load) and neuropsychological performance was not correlated with cortico-striatal rs-fc. CONCLUSIONS HIV was associated with disrupted cortico-striatal networks, consistent with HIV's known impact on the subcortical areas. Interestingly, within certain networks, HIV+/cART+ individuals had similar rs-fc compared to HIV- controls, suggesting possible improvements in HIV-related neural dysfunction due to medications. Rs-fc may be a sensitive biomarker of neural insult and its recovery following cART. Additional studies may show rs-fc has utility in measuring acute inflammation caused by HIV.
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Kelly EA, Tremblay ME, Gahmberg CG, Tian L, Majewska AK. Subcellular localization of intercellular adhesion molecule-5 (telencephalin) in the visual cortex is not developmentally regulated in the absence of matrix metalloproteinase-9. J Comp Neurol 2014; 522:676-88. [PMID: 23897576 DOI: 10.1002/cne.23440] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Revised: 07/11/2012] [Accepted: 07/18/2013] [Indexed: 02/06/2023]
Abstract
The telencephalon-associated intercellular adhesion molecule-5 (telencephalin; ICAM-5) regulates dendritic morphology in the developing brain. In vitro studies have shown that ICAM-5 is found predominantly within dendrites and immature dendritic protrusions, with reduced expression in mushroom spines, suggesting that ICAM-5 downregulation is critical for the maturation of synaptic structures. However, developmental expression of ICAM-5 has not been explored in depth at the ultrastructural level in intact brain tissue. To investigate the ultrastructural localization of ICAM-5 with transmission electron microscopy, we performed immunoperoxidase histochemistry for ICAM-5 in mouse visual cortex at postnatal day (P)14, a period of intense synaptogenesis, and at P28, when synapses mature. We observed the expected ICAM-5 expression in dendritic protrusions and shafts at both P14 and P28. ICAM-5 expression in these dendritic protrusions decreased in prevalence with developmental age to become localized predominantly to dendritic shafts by P28. To understand better the relationship between ICAM-5 and the endopeptidase metalloproteinase-9 (MMP-9), which mediates ICAM-5 cleavage following glutamate activation during postnatal development, we also explored ICAM-5 expression in MMP-9 null animals. This analysis revealed a similar expression of ICAM-5 in dendritic elements at P14 and P28; however, an increased prevalence of ICAM-5 was noted in dendritic protrusions at P28 in the MMP-9 null animals, indicating that, in the absence of MMP-9, there is no developmental shift in ICAM-5 subcellular localization. Our ultrastructural observations shed light on possible functions mediated by ICAM-5 and their regulation by extracellular proteases.
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Affiliation(s)
- Emily A Kelly
- Department of Neurobiology and Anatomy, University of Rochester, Rochester, New York, 14642
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HIV transactivator of transcription enhances methamphetamine-induced Parkinson's-like behavior in the rats. Neuroreport 2014; 25:860-864. [PMID: 24911386 PMCID: PMC4236185 DOI: 10.1097/wnr.0000000000000199] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Abuse of methamphetamine (MA) increases the risk of infection of HIV-1, induces considerable neurotoxicity in several brain regions, and impairs the motor and cognitive function in individuals. HIV-1 transactivator of transcription (Tat) has also shown the potent capability to induce neuronal death and impaired brain function. The present study aims to study the synergistic effect of MA and Tat on cytokine synthesis in substantia nigra, striatal dopamine content, and behavioral performance in the rats. Although increased expression of cytokines (interleukin-1β and tumor necrosis factor-α) was observed in the substantia nigra in the rats receiving either MA or Tat alone, a combination of MA and Tat induced a larger and more sustained upregulation of cytokines. In the rats receiving either MA or Tat alone, significant loss in striatal dopamine content was found, which was further exacerbated in the rats receiving both MA and Tat. In the rats receiving either MA or Tat alone, significantly lower performance in the rotarod test and open-field test was observed, whereas the rats receiving both MA and Tat showed more sustained behavioral impairments. These results suggested that Tat protein synergized with MA to induce central neuroinflammation and impair the dopaminergic transmission, thus leading to sustained Parkinson's-like behavior.
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33
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Santiago AR, Baptista FI, Santos PF, Cristóvão G, Ambrósio AF, Cunha RA, Gomes CA. Role of microglia adenosine A(2A) receptors in retinal and brain neurodegenerative diseases. Mediators Inflamm 2014; 2014:465694. [PMID: 25132733 PMCID: PMC4124703 DOI: 10.1155/2014/465694] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/20/2014] [Indexed: 12/20/2022] Open
Abstract
Neuroinflammation mediated by microglial cells in the brain has been commonly associated with neurodegenerative diseases. Whether this microglia-mediated neuroinflammation is cause or consequence of neurodegeneration is still a matter of controversy. However, it is unequivocal that chronic neuroinflammation plays a role in disease progression and halting that process represents a potential therapeutic strategy. The neuromodulator adenosine emerges as a promising targeting candidate based on its ability to regulate microglial proliferation, chemotaxis, and reactivity through the activation of its G protein coupled A2A receptor (A2AR). This is in striking agreement with the ability of A2AR blockade to control several brain diseases. Retinal degenerative diseases have been also associated with microglia-mediated neuroinflammation, but the role of A2AR has been scarcely explored. This review aims to compare inflammatory features of Parkinson's and Alzheimer's diseases with glaucoma and diabetic retinopathy, discussing the therapeutic potential of A2AR in these degenerative conditions.
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Affiliation(s)
- Ana R. Santiago
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- AIBILI, 3000-548 Coimbra, Portugal
- Center for Neuroscience and Cell Biology, Largo Marquês de Pombal, Universidade de Coimbra, 3004-517 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548 Coimbra, Portugal
| | - Filipa I. Baptista
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Paulo F. Santos
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Neuroscience and Cell Biology, Largo Marquês de Pombal, Universidade de Coimbra, 3004-517 Coimbra, Portugal
- Department of Life Sciences, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| | - Gonçalo Cristóvão
- Center for Neuroscience and Cell Biology, Largo Marquês de Pombal, Universidade de Coimbra, 3004-517 Coimbra, Portugal
| | - António F. Ambrósio
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- AIBILI, 3000-548 Coimbra, Portugal
- Center for Neuroscience and Cell Biology, Largo Marquês de Pombal, Universidade de Coimbra, 3004-517 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548 Coimbra, Portugal
| | - Rodrigo A. Cunha
- Center for Neuroscience and Cell Biology, Largo Marquês de Pombal, Universidade de Coimbra, 3004-517 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548 Coimbra, Portugal
| | - Catarina A. Gomes
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Neuroscience and Cell Biology, Largo Marquês de Pombal, Universidade de Coimbra, 3004-517 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548 Coimbra, Portugal
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Brailoiu E, Deliu E, Sporici RA, Benamar K, Brailoiu GC. HIV-1-Tat excites cardiac parasympathetic neurons of nucleus ambiguus and triggers prolonged bradycardia in conscious rats. Am J Physiol Regul Integr Comp Physiol 2014; 306:R814-22. [PMID: 24694382 DOI: 10.1152/ajpregu.00529.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mechanisms of autonomic imbalance and subsequent cardiovascular manifestations in HIV-1-infected patients are poorly understood. We report here that HIV-1 transactivator of transcription (Tat, fragment 1-86) produced a concentration-dependent increase in cytosolic Ca(2+) in cardiac-projecting parasympathetic neurons of nucleus ambiguus retrogradely labeled with rhodamine. Using store-specific pharmacological agents, we identified several mechanisms of the Tat-induced Ca(2+) elevation: 1) lysosomal Ca(2+) mobilization, 2) Ca(2+) release via inositol 1,4,5-trisphosphate-sensitive endoplasmic reticulum pools, and 3) Ca(2+) influx via transient receptor potential vanilloid type 2 (TRPV2) channels. Activation of TRPV2, nonselective cation channels, induced a robust and prolonged neuronal membrane depolarization, thus triggering an additional P/Q-mediated Ca(2+) entry. In vivo microinjection studies indicate a dose-dependent, prolonged bradycardic effect of Tat administration into the nucleus ambiguus of conscious rats, in which neuronal TRPV2 played a major role. Our results support previous studies, indicating that Tat promotes bradycardia and, consequently, may be involved in the QT interval prolongation reported in HIV-infected patients. In the context of an overall HIV-dependent autonomic dysfunction, these Tat-mediated mechanisms may account for the higher prevalence of sudden cardiac death in HIV-1-infected patients compared with general population with similar risk factors. Our results may be particularly relevant in view of the recent findings that significant Tat levels can still be identified in the cerebrospinal fluid of HIV-infected patients with viral load suppression due to efficient antiretroviral therapy.
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Affiliation(s)
- Eugen Brailoiu
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Elena Deliu
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Romeo A Sporici
- Department of Internal Medicine, Brandywine Hospital, Coatesville, Pennsylvania
| | - Khalid Benamar
- Center for Substance Abuse, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - G Cristina Brailoiu
- Department of Pharmaceutical Sciences, Thomas Jefferson University, Jefferson School of Pharmacy, Philadelphia, Pennsylvania
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35
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Kumar A, Herbein G. The macrophage: a therapeutic target in HIV-1 infection. MOLECULAR AND CELLULAR THERAPIES 2014; 2:10. [PMID: 26056579 PMCID: PMC4452058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 01/27/2014] [Indexed: 11/21/2023]
Abstract
Human immunodeficiency virus (HIV) is still a serious global health concern responsible for more than 25 million deaths in last three decades. More than 34 million people are living with HIV infection. Macrophages and CD4+ T cells are the principal targets of HIV-1. The pathogenesis of HIV-1 takes different routes in macrophages and CD4+ T cells. Macrophages are resistant to the cytopathic effect of HIV-1 and produce virus for longer periods of time. In addition, macrophages being present in every organ system thus can disseminate virus to the different anatomical sites leading to the formation of viral sanctuaries. Complete cure of HIV-1 needs better understanding of viral pathogenesis in these reservoirs and implementation of knowledge into robust therapeutic products. In this review we will focus on the unique relationship between HIV-1 and macrophages. Furthermore, we will describe how successful antiretroviral therapy (ART) is in suppressing HIV and novel molecular and cellular strategies against HIV-1 in macrophages.
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Affiliation(s)
- Amit Kumar
- />Department of Virology, UPRES EA4266 Pathogens & Inflammation, University of Franche-Comte, SFR FED 4234, F-25030 Besançon, France
| | - Georges Herbein
- />Department of Virology, UPRES EA4266 Pathogens & Inflammation, University of Franche-Comte, SFR FED 4234, F-25030 Besançon, France
- />Department of Virology, Hôpital Saint-Jacques, CHRU Besançon, 2 place Saint-Jacques, F-25030 Besançon cedex, France
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36
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Kumar A, Herbein G. The macrophage: a therapeutic target in HIV-1 infection. MOLECULAR AND CELLULAR THERAPIES 2014; 2:10. [PMID: 26056579 PMCID: PMC4452058 DOI: 10.1186/2052-8426-2-10] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 01/27/2014] [Indexed: 12/21/2022]
Abstract
Human immunodeficiency virus (HIV) is still a serious global health concern responsible for more than 25 million deaths in last three decades. More than 34 million people are living with HIV infection. Macrophages and CD4+ T cells are the principal targets of HIV-1. The pathogenesis of HIV-1 takes different routes in macrophages and CD4+ T cells. Macrophages are resistant to the cytopathic effect of HIV-1 and produce virus for longer periods of time. In addition, macrophages being present in every organ system thus can disseminate virus to the different anatomical sites leading to the formation of viral sanctuaries. Complete cure of HIV-1 needs better understanding of viral pathogenesis in these reservoirs and implementation of knowledge into robust therapeutic products. In this review we will focus on the unique relationship between HIV-1 and macrophages. Furthermore, we will describe how successful antiretroviral therapy (ART) is in suppressing HIV and novel molecular and cellular strategies against HIV-1 in macrophages.
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Affiliation(s)
- Amit Kumar
- Department of Virology, UPRES EA4266 Pathogens & Inflammation, University of Franche-Comte, SFR FED 4234, F-25030 Besançon, France
| | - Georges Herbein
- Department of Virology, UPRES EA4266 Pathogens & Inflammation, University of Franche-Comte, SFR FED 4234, F-25030 Besançon, France ; Department of Virology, Hôpital Saint-Jacques, CHRU Besançon, 2 place Saint-Jacques, F-25030 Besançon cedex, France
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37
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Miron VE, Franklin RJM. Macrophages and CNS remyelination. J Neurochem 2014; 130:165-71. [PMID: 24601941 DOI: 10.1111/jnc.12705] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 02/24/2014] [Indexed: 12/14/2022]
Abstract
Microglia are the resident macrophages of the central nervous system that survey the microenvironment for signals of injury or infection. The response to such signals induces an inflammatory response involving macrophages derived from both resident microglia and recruited circulating monocytes. Although implicated as contributors to autoimmune-mediated injury, microglia/ macrophages have recently been shown to be critical for the important central nervous system regenerative process of remyelination. This functional dichotomy may reflect their ability to be polarized along a continuum of activation states including the well-characterized cytotoxic M1 and regenerative M2 phenotypes. Here, we review the roles of microglia, monocytes and the macrophages which they give rise to in creating lesion environments favourable to remyelination, highlighting the specific roles of M1 and M2 phenotypes and how the pro-regenerative role of the innate immune system is altered by ageing. Here, we review the roles of microglia, monocytes and the macrophages, which they give rise to in creating lesion environments favourable to remyelination, highlighting the specific roles of activation phenotypes and how the pro-regenerative role of the innate immune system is altered by ageing.
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Affiliation(s)
- Veronique E Miron
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, UK
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38
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Krishnan G, Chatterjee N. Endocannabinoids affect innate immunity of Muller glia during HIV-1 Tat cytotoxicity. Mol Cell Neurosci 2014; 59:10-23. [DOI: 10.1016/j.mcn.2014.01.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/20/2013] [Accepted: 01/03/2014] [Indexed: 01/14/2023] Open
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39
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Tremblay MÈ, Marker DF, Puccini JM, Muly EC, Lu SM, Gelbard HA. Ultrastructure of microglia-synapse interactions in the HIV-1 Tat-injected murine central nervous system. Commun Integr Biol 2013; 6:e27670. [PMID: 24563721 DOI: 10.4161/cib.27670] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 12/25/2013] [Accepted: 12/27/2013] [Indexed: 01/26/2023] Open
Abstract
The destruction of normal synaptic architecture is the main pathogenetic substrate in HIV-associated neurocognitive disorder (HAND), but the sequence of cellular events underlying this outcome is not completely understood. Our recent work in a mouse model of HAND using a single intraparenchymal injection of the HIV-1 regulatory protein trans-activator of transcription revealed increased microglial phagocytosis that was accompanied by an increased release of pro-inflammatory cytokines and elimination of dendritic spines in vivo, thus suggesting that microglia-synapse interactions could be dysregulated in HAND. Here, we further examine the relationships between microglia and synaptic structures in our mouse model, at high spatial resolution using immunocytochemical electron microscopy. Our ultrastructural analysis reveals the prevalence of putative microglial filopodial protrusions, which are targeting excitatory and inhibitory synapses, some of which contain phagocytic inclusions at various distances from their distal extremities to the microglial cell bodies. These observations thus suggest that cell-to-cell contacts mediated by microglial filopodia might be a crucial preliminary step in the elimination of synaptic structures in a neuroinflammatory milieu that occurs in HAND.
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Affiliation(s)
- Marie-Ève Tremblay
- Axe Neurosciences; Centre de recherche du CHU de Québec; and Department of Molecular Medicine; Université Laval; Québec, QC Canada
| | - Daniel F Marker
- Center for Neural Development and Disease; University of Rochester; Rochester, NY USA
| | - Jenna M Puccini
- Center for Neural Development and Disease; University of Rochester; Rochester, NY USA
| | - E Chris Muly
- Atlanta Department of Veterans Affairs Medical Center; Decatur, GA USA
| | - Shao-Ming Lu
- Center for Neural Development and Disease; University of Rochester; Rochester, NY USA
| | - Harris A Gelbard
- Center for Neural Development and Disease; University of Rochester; Rochester, NY USA
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40
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Bagashev A, Sawaya BE. Roles and functions of HIV-1 Tat protein in the CNS: an overview. Virol J 2013; 10:358. [PMID: 24359561 PMCID: PMC3879180 DOI: 10.1186/1743-422x-10-358] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 12/06/2013] [Indexed: 01/01/2023] Open
Abstract
Nearly 50% of HIV-infected individuals suffer from some form of HIV-associated neurocognitive disorders (HAND). HIV-1 Tat (a key HIV transactivator of transcription) protein is one of the first HIV proteins to be expressed after infection occurs and is absolutely required for the initiation of the HIV genome transcription. In addition to its canonical functions, various studies have shown the deleterious role of HIV-1 Tat in the development and progression of HAND. Within the CNS, only specific cell types can support productive viral replication (astrocytes and microglia), however Tat protein can be released form infected cells to affects HIV non-permissive cells such as neurons. Therefore, in this review, we will summarize the functions of HIV-1 Tat proteins in neural cells and its ability to promote HAND.
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Affiliation(s)
| | - Bassel E Sawaya
- Molecular Studies of Neurodegenerative Diseases Lab, The Fels Institute for Cancer Research & Molecular Biology, Philadelphia, PA 19140, USA.
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41
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Šišková Z, Tremblay MÈ. Microglia and synapse: interactions in health and neurodegeneration. Neural Plast 2013; 2013:425845. [PMID: 24392228 PMCID: PMC3874338 DOI: 10.1155/2013/425845] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 09/30/2013] [Accepted: 10/19/2013] [Indexed: 01/04/2023] Open
Abstract
A series of discoveries spanning for the last few years has challenged our view of microglial function, the main form of immune defense in the brain. The surveillance of neuronal circuits executed by each microglial cell overseeing its territory occurs in the form of regular, dynamic interactions. Microglial contacts with individual neuronal compartments, such as dendritic spines and axonal terminals, ensure that redundant or dysfunctional elements are recognized and eliminated from the brain. Microglia take on a new shape that is large and amoeboid when a threat to brain integrity is detected. In this defensive form, they migrate to the endangered sites, where they help to minimize the extent of the brain insult. However, in neurodegenerative diseases that are associated with misfolding and aggregation of synaptic proteins, these vital defensive functions appear to be compromised. Many microglial functions, such as phagocytosis, might be overwhelmed during exposure to the abnormal levels of misfolded proteins in their proximity. This might prevent them from attending to their normal duties, such as the stripping of degenerating synaptic terminals, before neuronal function is irreparably impaired. In these conditions microglia become chronically activated and appear to take on new, destructive roles by direct or indirect inflammatory attack.
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Affiliation(s)
- Zuzana Šišková
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Département de Médecine Moléculaire, Université Laval, 2705 Boulevard Laurier, Québec, QC, Canada G1V 4G2
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42
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Kelly EA, Tremblay MÈ, Gahmberg CG, Tian L, Majewska AK. Interactions between intercellular adhesion molecule-5 positive elements and their surroundings in the rodent visual cortex. Commun Integr Biol 2013; 6:e27315. [PMID: 24753788 PMCID: PMC3984291 DOI: 10.4161/cib.27315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/21/2013] [Accepted: 11/22/2013] [Indexed: 11/19/2022] Open
Abstract
The telencephalon-associated intercellular adhesion molecule 5 (Telencephalin; ICAM-5) regulates dendritic maturation, a process dependent on extracellular proteases in the developing brain. Using transmission electron microscopy, we have reported previously that ICAM-5 is localized primarily in dendritic protrusions during a period of robust synaptogenesis (P14 in mouse visual cortex). As dendritic protrusions mature (P28), ICAM-5 immuno-reactivity shifts from dendritic protrusions into dendritic shafts. ICAM-5 immuno-reactivity does not shift in animals lacking the matrix metalloproteinase-9 (MMP-9), a protease shown to regulate ICAM-5 cleavage. Cleaved ICAM-5 (soluble fraction; sICAM-5) has been shown to bind to a number of receptors located in neighboring structures, resulting in a variety of downstream signaling events, including enhanced neurotransmission. Here, we investigated the potential MMP-regulated ICAM-5 signaling by examining the relationship between ICAM-5 immuno-positive elements and the structures that directly neighbor them.
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Affiliation(s)
- Emily A Kelly
- Neurobiology & Anatomy; University of Rochester; Rochester, NY USA
| | | | - Carl G Gahmberg
- Department of Bioscience; University of Helsinki; Helsinki, Finland
| | - Li Tian
- Neuroscience Center; University of Helsinki; Helsinki, Finland
| | - Ania K Majewska
- Neurobiology & Anatomy; University of Rochester; Rochester, NY USA
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43
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Nath A, Steiner J. Synaptodendritic injury with HIV-Tat protein: What is the therapeutic target? Exp Neurol 2013; 251:112-4. [PMID: 24246278 DOI: 10.1016/j.expneurol.2013.11.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 11/04/2013] [Indexed: 10/26/2022]
Affiliation(s)
- Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA; Translational Neuroscience Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Joseph Steiner
- Translational Neuroscience Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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44
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Lee PC, He HY, Lin CY, Ching YT, Cline HT. Computer aided alignment and quantitative 4D structural plasticity analysis of neurons. Neuroinformatics 2013; 11:249-57. [PMID: 23408326 DOI: 10.1007/s12021-013-9179-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The rapid development of microscopic imaging techniques has greatly facilitated time-lapse imaging of neuronal morphology. However, analysis of structural dynamics in the vast amount of 4-Dimensional data generated by in vivo or ex vivo time-lapse imaging still relies heavily on manual comparison, which is not only laborious, but also introduces errors and discrepancies between individual researchers and greatly limits the research pace. Here we present a supervised 4D Structural Plasticity Analysis (4D SPA) computer method to align and match 3-Dimensional neuronal structures across different time points on a semi-automated basis. We demonstrate 2 applications of the method to analyze time-lapse data showing gross morphological changes in dendritic arbor morphology and to identify the distribution and types of branch dynamics seen in a series of time-lapse images. Analysis of the dynamic changes of neuronal structure can be done much faster and with greatly improved consistency and reliability with the 4D SPA supervised computer program. Users can format the neuronal reconstruction data to be used for this analysis. We provide file converters for Neurolucida and Imaris users. The program and user manual are publically accessible and operate through a graphical user interface on Windows and Mac OSX.
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Affiliation(s)
- Ping-Chang Lee
- Industrial Technology Research Institute, Hsin Chu, Taiwan
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45
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Marker DF, Tremblay MÈ, Puccini JM, Barbieri J, Gantz Marker MA, Loweth CJ, Muly EC, Lu SM, Goodfellow VS, Dewhurst S, Gelbard HA. The new small-molecule mixed-lineage kinase 3 inhibitor URMC-099 is neuroprotective and anti-inflammatory in models of human immunodeficiency virus-associated neurocognitive disorders. J Neurosci 2013; 33:9998-10010. [PMID: 23761895 PMCID: PMC3682381 DOI: 10.1523/jneurosci.0598-13.2013] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/09/2013] [Accepted: 05/06/2013] [Indexed: 01/11/2023] Open
Abstract
Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) is a significant source of disability in the HIV-infected population. Even with stringent adherence to anti-retroviral therapy, >50% of patients living with HIV-1 will develop HAND (Heaton et al., 2010). Because suppression of viral replication alone is not enough to stop HAND progression, there is a need for an adjunctive neuroprotective therapy in this population. To this end, we have developed a small-molecule brain-penetrant inhibitor with activity against mixed-lineage kinase 3 (MLK3), named URMC-099. MLK3 activation is associated with many of the pathologic hallmarks of HAND (Bodner et al., 2002, 2004; Sui et al., 2006) and therefore represents a prime target for adjunctive therapy based on small-molecule kinase inhibition. Here we demonstrate the anti-inflammatory and neuroprotective effects of URMC-099 in multiple murine and rodent models of HAND. In vitro, URMC-099 treatment reduced inflammatory cytokine production by HIV-1 Tat-exposed microglia and prevented destruction and phagocytosis of cultured neuronal axons by these cells. In vivo, URMC-099 treatment reduced inflammatory cytokine production, protected neuronal architecture, and altered the morphologic and ultrastructural response of microglia to HIV-1 Tat exposure. In conclusion, these data provide compelling in vitro and in vivo evidence to investigate the utility of URMC-099 in other models of HAND with the goal of advancement to an adjunctive therapeutic agent.
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MESH Headings
- Animals
- Bone Marrow Transplantation
- CX3C Chemokine Receptor 1
- Cell Line, Transformed/drug effects
- Cell Line, Transformed/virology
- Cells, Cultured
- Cytokines
- Disease Models, Animal
- Embryo, Mammalian
- Gene Products, tat/immunology
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- HIV Infections/complications
- HIV Infections/drug therapy
- HIV Infections/virology
- HIV-1/physiology
- Hippocampus/pathology
- Humans
- Inflammation/genetics
- Inflammation/pathology
- Inflammation/prevention & control
- Inflammation/virology
- MAP Kinase Kinase Kinases/antagonists & inhibitors
- Mice
- Mice, Transgenic
- Microscopy, Immunoelectron
- Neuroprotective Agents/therapeutic use
- Phagocytosis/drug effects
- Phagocytosis/genetics
- Phosphorylation/drug effects
- Pyridines/pharmacology
- Pyridines/therapeutic use
- Pyrroles/pharmacology
- Pyrroles/therapeutic use
- Rats
- Receptors, Chemokine/genetics
- Receptors, Chemokine/metabolism
- Signal Transduction/drug effects
- Signal Transduction/genetics
- Statistics, Nonparametric
- Time Factors
- Transfection
- tat Gene Products, Human Immunodeficiency Virus
- Mitogen-Activated Protein Kinase Kinase Kinase 11
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Affiliation(s)
- Daniel F Marker
- Centers for Neural Development and Disease, University of Rochester, Rochester, New York 14642, USA.
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Carey AN, Liu X, Mintzopoulos D, Paris JJ, Muschamp JW, McLaughlin JP, Kaufman MJ. Conditional Tat protein expression in the GT-tg bigenic mouse brain induces gray matter density reductions. Prog Neuropsychopharmacol Biol Psychiatry 2013; 43:49-54. [PMID: 23269344 PMCID: PMC3612135 DOI: 10.1016/j.pnpbp.2012.12.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 12/04/2012] [Accepted: 12/19/2012] [Indexed: 12/14/2022]
Abstract
Tat (Trans-activator of transcription) is implicated in the neuropathogenesis of HIV-1 infection and known to contribute to neuronal damage and learning and memory impairments. However, direct neuroanatomical demonstration of Tat pathobiology is limited. GT-tg bigenic mice with a doxycycline (Dox)-inducible and brain-selective tat gene were used to test the hypothesis that conditional induction of Tat activity in brain can induce gray matter density abnormalities. Ultra high spatial resolution ex vivo magnetic resonance imaging (MRI) combined with a voxel based morphometry (VBM) analysis revealed gray matter density reductions in the sublenticular extended amygdala, the amygdala, the amygdala-hippocampal area, piriform and peri-/entorhinal cortices, and hypothalamus, in Tat-expressing GT-tg mice compared to Dox-treated C57Bl/6J mice. These neuroanatomical abnormalities are consistent with regions expected to be abnormal based on behavioral deficits exhibited by Tat-expressing mice (Carey et al., 2012). These experiments provide the first neuroimaging evidence that conditional Tat protein expression in the GT-tg bigenic mouse model alters brain structure. The findings warrant future studies to further characterize effects of conditional Tat expression on brain structure. Such studies may improve our understanding of the neurological underpinnings of neuroAIDS and the neurodegeneration associated with HIV-1 infection, potentially leading to new treatments.
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Affiliation(s)
- Amanda N. Carey
- Northeastern University, Department of Psychology, Boston, Massachusetts 02115, USA,Simmons College, Department of Psychology, Boston, MA 02115, USA
| | - Xiaoxu Liu
- McLean Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, USA
| | | | - Jason J. Paris
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987, USA
| | - John W. Muschamp
- McLean Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, USA
| | - Jay P. McLaughlin
- Northeastern University, Department of Psychology, Boston, Massachusetts 02115, USA,Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987, USA
| | - Marc J. Kaufman
- McLean Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, USA,Corresponding author: Dr. Marc J. Kaufman, McLean Imaging Center, McLean Hospital, 115 Mill St., Belmont, MA 02478 USA, Phone: (617)-855-3469, Fax: (617) 855-2770,
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Desplats P, Dumaop W, Smith D, Adame A, Everall I, Letendre S, Ellis R, Cherner M, Grant I, Masliah E. Molecular and pathologic insights from latent HIV-1 infection in the human brain. Neurology 2013; 80:1415-23. [PMID: 23486877 DOI: 10.1212/wnl.0b013e31828c2e9e] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE We aimed to investigate whether HIV latency in the CNS might have adverse molecular, pathologic, and clinical consequences. METHODS This was a case-control comparison of HIV-1 seropositive (HIV+) patients with clinical and neuropathologic examination. Based on the levels of HIV-1 DNA, RNA, and p24 in the brain, cases were classified as controls, latent HIV CNS infection, and HIV encephalitis (HIVE). Analysis of epigenetic markers including BCL11B, neurodegeneration, and neuroinflammation was performed utilizing immunoblot, confocal microscopy, immunochemistry/image analysis, and qPCR. Detailed antemortem neurocognitive data were available for 23 out of the 32 cases. RESULTS HIV+ controls (n = 12) had no detectable HIV-1 DNA, RNA, or p24 in the CNS; latent HIV+ cases (n = 10) showed high levels of HIV-1 DNA but no HIV RNA or p24; and HIVE cases (n = 10) had high levels of HIV-1 DNA, RNA, and p24. Compared to HIV+ controls, the HIV+ latent cases displayed moderate cognitive impairment with neurodegenerative and neuroinflammatory alterations, although to a lesser extent than HIVE cases. Remarkably, HIV+ latent cases showed higher levels of BCL11B and other chromatin modifiers involved in silencing. Increased BCL11B was associated with deregulation of proinflammatory genes like interleukin-6, tumor necrosis factor-α, and CD74. CONCLUSION Persistence of latent HIV-1 infection in the CNS was associated with increased levels of chromatin modifiers, including BCL11B. Alteration of these epigenetic factors might result in abnormal transcriptomes, leading to inflammation, neurodegeneration, and neurocognitive impairment. BCL11B and other epigenetic factors involved in silencing might represent potential targets for HIV-1 involvement of the CNS.
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Affiliation(s)
- Paula Desplats
- Department of Neurosciences, University of California San Diego, La Jolla, USA
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Yao H, Duan M, Yang L, Buch S. Nonmuscle myosin light-chain kinase mediates microglial migration induced by HIV Tat: involvement of β1 integrins. FASEB J 2013; 27:1532-48. [PMID: 23292072 DOI: 10.1096/fj.12-219600] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
One of the hallmark features of HIV-associated neurological disease is increased activation and migration of microglia. HIV transactivator of transcription (Tat) is released from infected cells and has the ability to recruit microglia. The purpose of this study was to investigate molecular mechanisms by which recombinant Tat₁₋₇₂, but not heated-inactive Tat₁₋₇₂,induces migration of rat primary microglia. Using primary microglia in Boyden chambers, we demonstrated the role of nonmuscle myosin light-chain kinase (nmMYLK) in Tat₁₋₇₂ (14.4 nM)-mediated increased microglial migration (up to 171.85%). These findings were validated using microglia isolated from wild-type (WT) or nmMYLK(-/-) mice in Dunn chamber assays. Tat₁₋₇₂-mediated activation of nmMYLK resulted in "inside-out" activation of β1 integrin, followed by "outside-in" activation of c-Src, Pyk2, and Cdc42-GTP (using G-LISA in primary and nmMYLK(-/-) microglia) and, subsequently, actin polymerization (flow cytometry and Western blot assays). In vivo corroboration of these findings demonstrated decreased migration of nmMYLK(-/-) microglia (2 × 10(5) cells transplanted into corpus callosum) compared with WT microglia toward microinjected Tat₁₋₇₂ (2 μg/mouse) in hippocampus. Up-regulation of nmMYLK in microglia was also detected in sections of basal ganglia from humans with HIV-encephalitis compared with uninfected controls. nmMYLK is thus critical for eliciting microglial migration during the innate immune response.
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Affiliation(s)
- Honghong Yao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska 68198-5880, USA
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Davidson DC, Hirschman MP, Sun A, Singh MV, Kasischke K, Maggirwar SB. Excess soluble CD40L contributes to blood brain barrier permeability in vivo: implications for HIV-associated neurocognitive disorders. PLoS One 2012; 7:e51793. [PMID: 23251626 PMCID: PMC3520914 DOI: 10.1371/journal.pone.0051793] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/08/2012] [Indexed: 02/03/2023] Open
Abstract
Despite the use of anti-retroviral therapies, a majority of HIV-infected individuals still develop HIV-Associated Neurocognitive Disorders (HAND), indicating that host inflammatory mediators, in addition to viral proteins, may be contributing to these disorders. Consistently, we have previously shown that levels of the inflammatory mediator soluble CD40L (sCD40L) are elevated in the circulation of HIV-infected, cognitively impaired individuals as compared to their infected, non-impaired counterparts. Recent studies from our group suggest a role for the CD40/CD40L dyad in blood brain barrier (BBB) permeability and interestingly, sCD40L is thought to regulate BBB permeability in other inflammatory disorders of the CNS. Using complementary multiphoton microscopy and quantitative analyses in wild-type and CD40L deficient mice, we now reveal that the HIV transactivator of transcription (Tat) can induce BBB permeability in a CD40L-dependent manner. This permeability of the BBB was found to be the result of aberrant platelet activation induced by Tat, since depletion of platelets prior to treatment reversed Tat-induced BBB permeability. Furthermore, Tat treatment led to an increase in granulocyte antigen 1 (Gr1) positive monocytes, indicating an expansion of the inflammatory subset of cells in these mice, which were found to adhere more readily to the brain microvasculature in Tat treated animals. Exploring the mechanisms by which the BBB becomes compromised during HIV infection has the potential to reveal novel therapeutic targets, thereby aiding in the development of adjunct therapies for the management of HAND, which are currently lacking.
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Affiliation(s)
- Donna C. Davidson
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Michael P. Hirschman
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Anita Sun
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Meera V. Singh
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Karl Kasischke
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
- Department of Neurology, University of Ulm Medical Center, Ulm, Germany
| | - Sanjay B. Maggirwar
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
- * E-mail:
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Marker DF, Puccini JM, Mockus TE, Barbieri J, Lu SM, Gelbard HA. LRRK2 kinase inhibition prevents pathological microglial phagocytosis in response to HIV-1 Tat protein. J Neuroinflammation 2012. [PMID: 23190742 PMCID: PMC3538654 DOI: 10.1186/1742-2094-9-261] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Human Immunodeficiency Virus-1 (HIV-1) associated neurocognitive disorders (HANDs) are accompanied by significant morbidity, which persists despite the use of combined antiretroviral therapy (cART). While activated microglia play a role in pathogenesis, changes in their immune effector functions, including phagocytosis and proinflammatory signaling pathways, are not well understood. We have identified leucine-rich repeat kinase 2 (LRRK2) as a novel regulator of microglial phagocytosis and activation in an in vitro model of HANDs, and hypothesize that LRRK2 kinase inhibition will attenuate microglial activation during HANDs. METHODS We treated BV-2 immortalized mouse microglia cells with the HIV-1 trans activator of transcription (Tat) protein in the absence or presence of LRRK2 kinase inhibitor (LRRK2i). We used Western blot, qRT-PCR, immunocytochemistry and latex bead engulfment assays to analyze LRRK2 protein levels, proinflammatory cytokine and phagocytosis receptor expression, LRRK2 cellular distribution and phagocytosis, respectively. Finally, we utilized ex vivo microfluidic chambers containing primary hippocampal neurons and BV-2 microglia cells to investigate microglial phagocytosis of neuronal axons. RESULTS We found that Tat-treatment of BV-2 cells induced kinase activity associated phosphorylation of serine 935 on LRRK2 and caused the formation of cytoplasmic LRRK2 inclusions. LRRK2i decreased Tat-induced phosphorylation of serine 935 on LRRK2 and inhibited the formation of Tat-induced cytoplasmic LRRK2 inclusions. LRRK2i also decreased Tat-induced process extension in BV-2 cells. Furthermore, LRRK2i attenuated Tat-induced cytokine expression and latex bead engulfment. We examined relevant cellular targets in microfluidic chambers and found that Tat-treated BV-2 microglia cells cleared axonal arbor and engulfed neuronal elements, whereas saline treated controls did not. LRRK2i was found to protect axons in the presence of Tat-activated microglia, as well as AnnexinV, a phosphatidylserine-binding protein. In addition, LRRK2i decreased brain-specific angiogenesis inhibitor 1 (BAI1) receptor expression on BV-2 cells after Tat-treatment, a key receptor in phosphatidylserine-mediated phagocytosis. CONCLUSION Taken together, these results implicate LRRK2 as a key player in microglial inflammation and, in particular, in the phagocytosis of neuronal elements. These studies show that LRRK2 kinase inhibition may prove an effective therapeutic strategy for HANDs, as well as other neuroinflammatory conditions.
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Affiliation(s)
- Daniel F Marker
- Center for Neural Development and Disease, Department of Neurology, Child Neurology Division, University of Rochester, Rochester, NY, USA
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