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Kim BH, Hadas E, Kelschenbach J, Chao W, Gu CJ, Potash MJ, Volsky DJ. CCL2 is required for initiation but not persistence of HIV infection mediated neurocognitive disease in mice. Sci Rep 2023; 13:6577. [PMID: 37085605 PMCID: PMC10121554 DOI: 10.1038/s41598-023-33491-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 04/13/2023] [Indexed: 04/23/2023] Open
Abstract
HIV enters the brain within days of infection causing neurocognitive impairment (NCI) in up to half of infected people despite suppressive antiretroviral therapy. The virus is believed to enter the brain in infected monocytes through chemotaxis to the major monocyte chemokine, CCL2, but the roles of CCL2 in established NCI are not fully defined. We addressed this question during infection of conventional and CCL2 knockout mice with EcoHIV in which NCI can be verified in behavioral tests. EcoHIV enters mouse brain within 5 days of infection, but NCI develops gradually with established cognitive disease starting 25 days after infection. CCL2 knockout mice infected by intraperitoneal injection of virus failed to develop brain infection and NCI. However, when EcoHIV was directly injected into the brain, CCL2 knockout mice developed NCI. Knockout of CCL2 or its principal receptor, CCR2, slightly reduced macrophage infection in culture. Treatment of mice prior to and during EcoHIV infection with the CCL2 transcriptional inhibitor, bindarit, prevented brain infection and NCI and reduced macrophage infection. In contrast, bindarit treatment of mice 4 weeks after infection affected neither brain virus burden nor NCI. Based on these findings we propose that HIV enters the brain mainly through infected monocytes but that resident brain cells are sufficient to maintain NCI. These findings suggest that NCI therapy must act within the brain.
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Affiliation(s)
- Boe-Hyun Kim
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA
| | - Eran Hadas
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA
| | - Jennifer Kelschenbach
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA
| | - Wei Chao
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA
| | - Chao-Jiang Gu
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA
- College of Life and Health Sciences, Institute of Biology and Medicine, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Mary Jane Potash
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA
| | - David J Volsky
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA.
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2
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Bai R, Song C, Lv S, Chang L, Hua W, Weng W, Wu H, Dai L. Role of microglia in HIV-1 infection. AIDS Res Ther 2023; 20:16. [PMID: 36927791 PMCID: PMC10018946 DOI: 10.1186/s12981-023-00511-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 03/10/2023] [Indexed: 03/18/2023] Open
Abstract
The usage of antiretroviral treatment (ART) has considerably decreased the morbidity and mortality related to HIV-1 (human immunodeficiency virus type 1) infection. However, ART is ineffective in eradicating the virus from the persistent cell reservoirs (e.g., microglia), noticeably hindering the cure for HIV-1. Microglia participate in the progression of neuroinflammation, brain aging, and HIV-1-associated neurocognitive disorder (HAND). Some methods have currently been studied as fundamental strategies targeting microglia. The purpose of this study was to comprehend microglia biology and its functions in HIV-1 infection, as well as to look into potential therapeutic approaches targeting microglia.
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Affiliation(s)
- Ruojing Bai
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, 100069, China
| | - Chengcheng Song
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Shiyun Lv
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, 100069, China
| | - Linlin Chang
- Department of Dermatology, Beijing Youan Hospital, Capital Medical University, Beijing, 100069, China
| | - Wei Hua
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, 100069, China
| | - Wenjia Weng
- Department of Dermatology, Beijing Youan Hospital, Capital Medical University, Beijing, 100069, China.
| | - Hao Wu
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, 100069, China.
| | - Lili Dai
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, 100069, China.
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3
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Altered expression of fractalkine in HIV-1-infected astrocytes and consequences for the virus-related neurotoxicity. J Neurovirol 2021; 27:279-301. [PMID: 33646495 DOI: 10.1007/s13365-021-00955-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 03/27/2020] [Accepted: 01/21/2021] [Indexed: 10/22/2022]
Abstract
HIV-1 infection in the central nervous system (CNS) causes the release of neurotoxic products from infected cells which trigger extensive neuronal loss. Clinically, this results in HIV-1-associated neurocognitive disorders (HAND). However, the effects on neuroprotective factors in the brain remain poorly understood and understudied in this situation. HAND is a multifactorial process involving several players, and the complex cellular mechanisms have not been fully elucidated yet. In this study, we reported that HIV-1 infection of astrocytes limits their potential to express the protective chemokine fractalkine in response to an inflammatory environment. We next confirmed that this effect was not due to a default in its shedding from the cell surface. We then investigated the biological mechanism responsible for this reduced fractalkine expression and found that HIV-1 infection specifically blocks the interaction of transcription factor NF-κB on its promoter with no effect on other cytokines. Moreover, we demonstrated that fractalkine production in astrocytes is regulated in response to immune factors secreted by infected/activated microglia and macrophages. In contrast, we observed that conditioned media from these infected cells also trigger neuronal apoptosis. At last, we demonstrated a strong neuroprotective action of fractalkine on human neurons by reducing neuronal damages. Taken together, our results indicate new relevant interactions between HIV-1 and fractalkine signaling in the CNS. This study provides new information to broaden the understanding of HAND and possibly foresee new therapeutic strategies. Considering its neuro-protective functions, reducing its production from astrocytes could have important outcomes in chronic neuroinflammation and in HIV-1 neuropathogenesis.
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McArthur JC, Johnson TP. Chronic inflammation mediates brain injury in HIV infection: relevance for cure strategies. Curr Opin Neurol 2021; 33:397-404. [PMID: 32209807 DOI: 10.1097/wco.0000000000000807] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW Chronic inflammation is a major component of HIV infection, the effects of which can be devastating in the central nervous system (CNS). Protecting the brain is, therefore, critical as efforts proceed to cure HIV infection by reactivating latent viral reservoirs and driving immune responses. We review the clinical presentation and pathology findings of inflammatory processes in the CNS in patients managed with ART and the drivers of these processes. RECENT FINDINGS Chronic inflammation is associated with increased mortality and morbidity and HIV infection increases the risk for chronic diseases, especially cognitive impairment. Latent viral reservoirs, including microglia and tissue macrophages, contribute to inflammation in the CNS. Inflammation is generated and maintained through residual viral replication, dysregulation of infected cells, continuously produced viral proteins and positive feedback loops of chronic inflammation. Novel therapeutics and lifestyle changes may help to protect the CNS from immune-mediated damage. SUMMARY As therapies are developed to cure HIV, it is important to protect the CNS from additional immune-mediated damage. Adjunctive therapies to restore glial function, reduce neuroinflammation and systemic inflammation, and inhibit expression of viral proteins are needed.
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Affiliation(s)
- Justin C McArthur
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
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Saloner R, Fields JA, Marcondes MCG, Iudicello JE, von Känel S, Cherner M, Letendre SL, Kaul M, Grant I. Methamphetamine and Cannabis: A Tale of Two Drugs and their Effects on HIV, Brain, and Behavior. J Neuroimmune Pharmacol 2020; 15:743-764. [PMID: 32929575 DOI: 10.1007/s11481-020-09957-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/10/2020] [Indexed: 12/12/2022]
Abstract
HIV infection and drug use intersect epidemiologically, and their combination can result in complex effects on brain and behavior. The extent to which drugs affect the health of persons with HIV (PWH) depends on many factors including drug characteristics, use patterns, stage of HIV disease and its treatment, comorbid factors, and age. To consider the range of drug effects, we have selected two that are in common use by PWH: methamphetamine and cannabis. We compare the effects of methamphetamine with those of cannabis, to illustrate how substances may potentiate, worsen, or even buffer the effects of HIV on the CNS. Data from human, animal, and ex vivo studies provide insights into how these drugs have differing effects on the persistent inflammatory state that characterizes HIV infection, including effects on viral replication, immune activation, mitochondrial function, gut permeability, blood brain barrier integrity, glia and neuronal signaling. Moving forward, we consider how these mechanistic insights may inform interventions to improve brain outcomes in PWH. This review summarizes literature from clinical and preclinical studies demonstrating the adverse effects of METH, as well as the potentially beneficial effects of cannabis, on the interacting systemic (e.g., gut barrier leakage/microbial translocation, immune activation, inflammation) and CNS-specific (e.g., glial activation/neuroinflammation, neural injury, mitochondrial toxicity/oxidative stress) mechanisms underlying HIV-associated neurocognitive disorders.
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Affiliation(s)
- Rowan Saloner
- Department of Psychiatry, HIV Neurobehavioral Research Program, University of California, San Diego, San Diego, CA, USA. .,Joint Doctoral Program in Clinical Psychology, San Diego State University/University of California, San Diego , San Diego, CA, USA.
| | - Jerel Adam Fields
- Department of Psychiatry, HIV Neurobehavioral Research Program, University of California, San Diego, San Diego, CA, USA
| | | | - Jennifer E Iudicello
- Department of Psychiatry, HIV Neurobehavioral Research Program, University of California, San Diego, San Diego, CA, USA
| | - Sofie von Känel
- Department of Psychiatry, HIV Neurobehavioral Research Program, University of California, San Diego, San Diego, CA, USA
| | - Mariana Cherner
- Department of Psychiatry, HIV Neurobehavioral Research Program, University of California, San Diego, San Diego, CA, USA
| | - Scott L Letendre
- Department of Psychiatry, HIV Neurobehavioral Research Program, University of California, San Diego, San Diego, CA, USA
| | - Marcus Kaul
- Department of Psychiatry, HIV Neurobehavioral Research Program, University of California, San Diego, San Diego, CA, USA.,Division of Biomedical Sciences, University of California, Riverside, Riverside, CA, USA
| | - Igor Grant
- Department of Psychiatry, HIV Neurobehavioral Research Program, University of California, San Diego, San Diego, CA, USA
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Long JY, Chen JM, Liao YJ, Zhou YJ, Liang BY, Zhou Y. Naringin provides neuroprotection in CCL2-induced cognition impairment by attenuating neuronal apoptosis in the hippocampus. Behav Brain Funct 2020; 16:4. [PMID: 32103758 PMCID: PMC7045422 DOI: 10.1186/s12993-020-00166-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 02/18/2020] [Indexed: 01/21/2023] Open
Abstract
Background Chemokine C–C motif ligand 2 (CCL2) is one of the most widely recognised proinflammatory chemokines in cognitive disorders. Currently, CCL2-targeting drugs are extremely limited. Thus, this study aimed to explore the neuroprotection afforded by naringin in CCL2-induced cognitive impairment in rats. Methods Before the CCL2 intra-hippocampal injection, rats were treated with naringin for 3 consecutive days via intraperitoneal injection. Two days post-surgery, the Morris water maze (MWM) and novel object recognition (NORT) tests were performed to detect spatial learning and memory and object cognition, respectively. Nissl staining and dUTP nick-end labelling (TUNEL) staining were performed to assess histopathological changes in the hippocampus. Commercial kits were used to measure the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the content of malondialdehyde (MDA). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to examine the relative mRNA expression of interleukin 1β, (IL-1β), interleukin 6 (IL-6), glutamate/aspartate transporter (GLAST), glutamate transporter-1 (GLT-1), phosphate-activated glutaminase (PAG), cysteine aspartic acid-specific protease 8 (caspase-8), cysteine aspartic acid-specific protease 3 (caspase-3), cell lymphoma/leukaemia-2 (Bcl-2), and Bcl-2 associated X protein (Bax). Results In the MWM, the average escape latency and average swimming distance were significantly reduced and the crossing times were increased in the naringin-treated groups, compared with the CCL2 group. The NORT results revealed that, compared with the CCL2 rats, the discrimination index in the naringin-treated rats increased significantly. Nissl and TUNEL staining revealed that naringin protected the structure and survival of the neurons in the CA1 zone of the hippocampus. In the naringin-treated groups, the SOD and GSH-Px activities were increased, whereas the MDA levels were decreased. Furthermore, in the naringin-treated groups, the relative mRNA expression of IL-1β and IL-6 was significantly decreased; GLAST and GLT-1 mRNA expression levels were increased, whereas PAG was decreased. In the naringin-treated groups, the relative mRNA expression levels of caspase-8, caspase-3, and Bax were decreased, whereas that of Bcl-2 was increased. Conclusion Collectively, these data indicated that naringin alleviated the CCL2-induced cognitive impairment. The underlying mechanisms could be associated with the inhibition of neuroinflammation, oxidative stress, apoptosis, and the regulation of glutamate metabolism.
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Affiliation(s)
- Jiang-Yi Long
- Department of Pharmacology, Guangxi Medical University, Nanning, 53002, Guangxi, China
| | - Jian-Min Chen
- Department of Pharmacology, Guangxi Medical University, Nanning, 53002, Guangxi, China
| | - Yuan-Jun Liao
- Department of Pharmacology, Guangxi Medical University, Nanning, 53002, Guangxi, China
| | - Yi-Jun Zhou
- Department of Pharmacology, Guangxi Medical University, Nanning, 53002, Guangxi, China
| | - Bing-Yu Liang
- Guangxi Key Laboratory of AIDS Prevention and Treatment, Guangxi Medical University, Nanning, 530021, Guang, China
| | - Yan Zhou
- Department of Pharmacology, Guangxi Medical University, Nanning, 53002, Guangxi, China.
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Rizzo MD, Crawford RB, Bach A, Sermet S, Amalfitano A, Kaminski NE. Δ 9-Tetrahydrocannabinol Suppresses Monocyte-Mediated Astrocyte Production of Monocyte Chemoattractant Protein 1 and Interleukin-6 in a Toll-Like Receptor 7-Stimulated Human Coculture. J Pharmacol Exp Ther 2019; 371:191-201. [PMID: 31383729 PMCID: PMC7184191 DOI: 10.1124/jpet.119.260661] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/01/2019] [Indexed: 01/23/2023] Open
Abstract
Cannabis is widely used in the United States, with an estimated prevalence of 9.5%. Certain cannabinoids in Cannabis sativa, Δ9-tetrahydrocannabinol (THC) in particular, possess immune-modulating and anti-inflammatory activity. Depending on the context, the anti-inflammatory activity of cannabinoids may be beneficial (e.g., in treating inflammatory diseases) or detrimental to normal immune defense against pathogens. The potential beneficial effect of cannabinoids on chronic neuroinflammation has gained recent attention. Monocyte migration to the brain has been implicated as a key event in chronic neuroinflammation and in the etiology of central nervous system diseases including viral infection (e.g., human immunodeficiency virus-associated neurocognitive disorder). In the brain, monocytes can contribute to neuroinflammation through interactions with astrocytes, including inducing astrocyte secretion of cytokines and chemokines. In a human coculture system, monocyte-derived interleukin (IL)-1β due to Toll-like receptor 7 (TLR7) activation has been identified to promote astrocyte production of monocyte chemoattractant protein (MCP)-1 and IL-6. THC treatment of the TLR7-stimulated coculture suppressed monocyte secretion of IL-1β, resulting in decreased astrocyte production of MCP-1 and IL-6. Furthermore, THC displayed direct inhibition of monocytes, as TLR7-stimulated monocyte monocultures treated with THC also showed suppressed IL-1β production. The cannabinoid receptor 2 (CB2) agonist, JWH-015, impaired monocyte IL-1β production similar to that of THC, suggesting that THC acts, in part, through CB2. THC also suppressed key elements of the IL-1β production pathway, including IL1B mRNA levels and caspase-1 activity. Collectively, this study demonstrates that the anti-inflammatory properties of THC suppress TLR7-induced monocyte secretion of IL-1β through CB2, which results in decreased astrocyte secretion of MCP-1 and IL-6. SIGNIFICANCE STATEMENT: Because cannabis use is highly prevalent in the United States and has putative anti-inflammatory properties, it is important to investigate the effect of cannabinoids on immune cell function. Furthermore, cannabinoids have garnered particular interest due to their potential beneficial effects on attenuating viral-induced chronic neuroinflammation. This study utilized a primary human coculture system to demonstrate that the major psychotropic cannabinoid in cannabis, Δ9-tetrahydrocannabinol, and a cannabinoid receptor-2 selective agonist suppress specific monocyte-mediated astrocyte inflammatory responses.
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Affiliation(s)
- Michael D Rizzo
- Cell and Molecular Biology Program (M.D.R.), Institute for Integrative Toxicology (M.D.R., R.B.C., N.E.K.), Center for Research on Ingredient Safety (A.B., N.E.K.), and Departments of Microbiology and Molecular Genetics (A.A.), Osteopathic Medicine (A.A.), and Pharmacology and Toxicology (S.S., N.E.K.), Michigan State University, East Lansing, Michigan
| | - Robert B Crawford
- Cell and Molecular Biology Program (M.D.R.), Institute for Integrative Toxicology (M.D.R., R.B.C., N.E.K.), Center for Research on Ingredient Safety (A.B., N.E.K.), and Departments of Microbiology and Molecular Genetics (A.A.), Osteopathic Medicine (A.A.), and Pharmacology and Toxicology (S.S., N.E.K.), Michigan State University, East Lansing, Michigan
| | - Anthony Bach
- Cell and Molecular Biology Program (M.D.R.), Institute for Integrative Toxicology (M.D.R., R.B.C., N.E.K.), Center for Research on Ingredient Safety (A.B., N.E.K.), and Departments of Microbiology and Molecular Genetics (A.A.), Osteopathic Medicine (A.A.), and Pharmacology and Toxicology (S.S., N.E.K.), Michigan State University, East Lansing, Michigan
| | - Sera Sermet
- Cell and Molecular Biology Program (M.D.R.), Institute for Integrative Toxicology (M.D.R., R.B.C., N.E.K.), Center for Research on Ingredient Safety (A.B., N.E.K.), and Departments of Microbiology and Molecular Genetics (A.A.), Osteopathic Medicine (A.A.), and Pharmacology and Toxicology (S.S., N.E.K.), Michigan State University, East Lansing, Michigan
| | - Andrea Amalfitano
- Cell and Molecular Biology Program (M.D.R.), Institute for Integrative Toxicology (M.D.R., R.B.C., N.E.K.), Center for Research on Ingredient Safety (A.B., N.E.K.), and Departments of Microbiology and Molecular Genetics (A.A.), Osteopathic Medicine (A.A.), and Pharmacology and Toxicology (S.S., N.E.K.), Michigan State University, East Lansing, Michigan
| | - Norbert E Kaminski
- Cell and Molecular Biology Program (M.D.R.), Institute for Integrative Toxicology (M.D.R., R.B.C., N.E.K.), Center for Research on Ingredient Safety (A.B., N.E.K.), and Departments of Microbiology and Molecular Genetics (A.A.), Osteopathic Medicine (A.A.), and Pharmacology and Toxicology (S.S., N.E.K.), Michigan State University, East Lansing, Michigan
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8
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Rizzo MD, Crawford RB, Bach A, Sermet S, Amalfitano A, Kaminski NE. Imiquimod and interferon-alpha augment monocyte-mediated astrocyte secretion of MCP-1, IL-6 and IP-10 in a human co-culture system. J Neuroimmunol 2019; 333:576969. [PMID: 31136945 DOI: 10.1016/j.jneuroim.2019.576969] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/10/2019] [Accepted: 05/17/2019] [Indexed: 12/11/2022]
Abstract
Toll-like receptor 7 (TLR7)-activation has been implicated as a significant mechanism of neuroinflammation triggered by ssRNA viruses. Infiltration of monocytes into the brain and astrocyte activation occurs during in vivo TLR7-mediated neuroinflammation. The objective here was to determine whether the TLR7 agonist, imiquimod, and interferon-alpha (IFN-α), promote monocyte-mediated astrocyte secretion of pro-inflammatory factors. Using a human primary co-culture system, we demonstrate that monocytes, together with imiquimod and IFN-α, promote astrocyte secretion of MCP-1, IL-6 and IP-10. Furthermore, TLR7-induced monocyte-derived IL-1β is critical for promoting the astrocyte response. Overall, this study provides a potential mechanism for TLR7-mediated neuroinflammation.
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Affiliation(s)
- Michael D Rizzo
- Michigan State University, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America; Cell & Molecular Biology Program, 1129 Farm Lane Rm. 311, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America; Institute for Integrative Toxicology, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America.
| | - Robert B Crawford
- Michigan State University, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America; Institute for Integrative Toxicology, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America
| | - Anthony Bach
- Michigan State University, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America; Institute for Integrative Toxicology, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America.
| | - Sera Sermet
- Michigan State University, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America.
| | - Andrea Amalfitano
- Michigan State University, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America; Department of Microbiology & Molecular Genetics, 4108 Biomedical Physical Sciences, East Lansing, MI 48824, United States of America; Department of Osteopathic Medicine, 4108 Biomedical Physical Sciences, East Lansing, MI 48824, United States of America.
| | - Norbert E Kaminski
- Michigan State University, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America; Institute for Integrative Toxicology, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America; Department of Pharmacology & Toxicology, 1129 Farm Lane Rm. 165G, Food Safety & Toxicology Bldg, East Lansing, MI 48824, United States of America.
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Fatima M, Prajapati B, Saleem K, Kumari R, Mohindar Singh Singal C, Seth P. Novel insights into role of miR-320a-VDAC1 axis in astrocyte-mediated neuronal damage in neuroAIDS. Glia 2016; 65:250-263. [PMID: 27761954 DOI: 10.1002/glia.23089] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 09/10/2016] [Accepted: 09/30/2016] [Indexed: 12/31/2022]
Abstract
Astroglia are indispensable component of the tripartite synapse ensheathing innumerous soma and synapses. Its proximity to neurons aids the regulation of neuronal functions, health and survival through dynamic neuroglia crosstalk. Susceptibility of astrocyte to HIV-1 infection and subsequent latency culminates in compromised neuronal health. The viral protein HIV-1 transactivator of transcription (Tat) is neurotoxic. HIV-1 Tat is detected in brain of AIDS patients even in cases where viral load is non-detectable due to successful HAART therapy. Recently, we demonstrated that HIV-1 Tat triggers excess ATP release from astrocytes that causes neuronal death by activating purinergic receptor system. Using well-characterized model system of human primary astrocytes and neurons, we probed into the molecular mechanism for enhanced ATP release in HIV-1 Tat affected astrocytes. HIV-1 Tat modulated the miRNA machinery in astrocytes and perturbed the levels of voltage dependent anion channel 1 (VDAC1), a channel present in the outer mitochondrial membrane and plasma membrane that regulates extracellular ATP release. Our studies with autopsy tissue sections also showed concordantly dysregulated VDAC1 and miR-320a levels in HIV-1 patients suffering from mild cognitive impairment (MCI). We report a novel molecular cascade of miRNA-mediated ATP release through regulation of VDAC1. Downregulation of VDAC1 either with miR-320a mimic or VDAC1 siRNA in HIV-1 Tat-affected astroglia could rescue the neurons from glia-mediated indirect death. Our findings reveal a novel upstream therapeutic target that could be employed to thwart the astroglia-mediated neurotoxicity in HIV-1 neuropathogenesis. GLIA 2017;65:250-263.
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Affiliation(s)
- Mahar Fatima
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Bharat Prajapati
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Kanza Saleem
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Rina Kumari
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Chitra Mohindar Singh Singal
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Pankaj Seth
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
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10
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Graziano F, Vicenzi E, Poli G. Immuno-Pharmacological Targeting of Virus-Containing Compartments in HIV-1-Infected Macrophages. Trends Microbiol 2016; 24:558-567. [PMID: 27012511 DOI: 10.1016/j.tim.2016.02.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 02/23/2016] [Accepted: 02/26/2016] [Indexed: 01/26/2023]
Abstract
In addition to CD4 T lymphocytes, HIV-1 infects tissue macrophages that can actively accumulate infectious virions in vacuolar subcellular structures mostly connected to the plasma membrane and recently termed virus-containing compartments (VCCs). The VCC-associated HIV-1 reservoir of infected macrophages can be either increased or depleted by immunologic and pharmacologic agents, at least in vitro, thus suggesting that these factors (or related molecules) could be effective in curtailing the macrophage-associated HIV-1 reservoir in infected individuals receiving combination antiretroviral therapy (cART). Here we review evidence on the pathogenic role of tissue macrophages as long-term viral reservoirs in vivo and upon in vitro infection with a particular emphasis on the immuno-pharmacological modulation of VCCs.
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Affiliation(s)
- Francesca Graziano
- AIDS Immunopathogenesis Unit, San Raffaele Scientific Institute, Milano, Italy
| | - Elisa Vicenzi
- Viral Pathogens and Biosafety Unit, San Raffaele Scientific Institute, Milano, Italy
| | - Guido Poli
- AIDS Immunopathogenesis Unit, San Raffaele Scientific Institute, Milano, Italy; Vita-Salute San Raffaele University, School of Medicine, Milano, Italy; Institute of Human Virology, University of Maryland, Baltimore, MD, USA.
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11
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Zhou Y, Tang H, Xiong H. Chemokine CCL2 enhances NMDA receptor-mediated excitatory postsynaptic current in rat hippocampal slices-a potential mechanism for HIV-1-associated neuropathy? J Neuroimmune Pharmacol 2016; 11:306-15. [PMID: 26968849 DOI: 10.1007/s11481-016-9660-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 02/24/2016] [Indexed: 11/24/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1)-infected mononuclear phagocytes (brain macrophages and microglial cells) release proinflammatory cytokines and chemokines. Elevated levels of chemokine CC motif ligand 2 (CCL2, known previously as monocyte chemoattractant protein-1) have been detected in serum and cerebrospinal fluid (CSF) of HIV-1-infected individuals and the raised CCL2 in the CSF correlates with HIV-1-associated neurocognitive disorders. To understand how elevated CCL2 induces HIV-1-associated neuropathy, we studied effects of CCL2 on excitatory postsynaptic current (EPSCs) in the CA1 region of rat hippocampal brain slices using whole-cell patch recording techniques. The AMPA receptor (AMPAR)-mediated EPSC (EPSCAMPAR) and N-Methyl-D-aspartate (NMDA) receptor (NMDAR)-mediated EPSCs (EPSCNMDAR) were isolated pharmacologically. Bath application of CCL2 produced a significant enhancement of the amplitudes of EPSCs, EPSCAMPAR and EPSCNMDAR. Further studies revealed that CCL2 potentiated NMDAR subtype NR2A-mediated EPSC (EPSCNR2AR) and NR2B-mediated EPSC (EPSCNR2BR). To determine the site of action, we recorded spontaneous mini EPSCs (mEPSC) before and during bath application of CCL2. Our results showed that CCL2 decreased inter event interval (IEI) and increased the frequency of mEPSCs without change on the amplitude, suggesting a presynaptic site of CCL2 action. CCL2 was also found to injure primary rat hippocampal neuronal cultures and neuronal dendrites in the CA1 region of hippocampal slices. The CCL2-associated neuronal and dendritic injuries were blocked by a specific NMDAR antagonist or by a CCR2 receptor antagonist, indicating that CCL2-associated neural injury was mediated via NMDARs and/or CCR2 receptors. Taken together, these results suggest a potential role CCL2 may play in HIV-1-associated neuropathology.
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Affiliation(s)
- Yan Zhou
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA. .,Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, People's Republic of China, 530021.
| | - Hongmei Tang
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA.,Department of Pathophysiology, Ji-nan University, Guangzhou, 510632, China
| | - Huangui Xiong
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA.
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Tewari M, Varghse RK, Menon M, Seth P. Astrocytes mediate HIV-1 Tat-induced neuronal damage via ligand-gated ion channel P2X7R. J Neurochem 2015; 132:464-76. [PMID: 25272052 DOI: 10.1111/jnc.12953] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/17/2014] [Accepted: 09/22/2014] [Indexed: 01/21/2023]
Abstract
During human immunodeficiency virus (HIV)-1 infection, perturbations in neuron–glia interactions may culminate in neuronal damage. Recently, purinergic receptors have been implicated in the promotion of virus-induced neurotoxicity and supporting the viral life cycle at multiple stages. The astrocytes robustly express purinergic receptors. We therefore sought to examine if P2X7R, a P2X receptor subtype, can mediate HIV-1 Tat-induced neuronal apoptosis. Tat augmented the expression of P2X7R in astrocytes. Our data reveal the involvement of P2X7R in Tat-mediated release of monocyte chemoattractant protein (MCP-1) /chemokine (C-C motif) ligand 2 (CCL2) from the astrocytes. P2X7R antagonists, such as the oxidized ATP, A438079, brilliant blue G, and broad spectrum P2 receptor antagonist suramin, attenuated Tat-induced CCL2 release in a calcium- and extracellular signal-regulated kinase (ERK)1/2-dependent manner. Calcium chelators, (1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid) acetoxymethyl ester and EGTA, and ERK1/2 inhibitor U0126 abolished chemokine (C-C motif) ligand 2 release from astrocytes. Furthermore, in human neuronal cultures, we demonstrated P2X7R involvement in Tat-mediated neuronal death. Importantly, in the TUNEL assay, the application of P2X7R-specific antagonists or the knockdown of P2X7R in human astrocytes reduced HIV-Tat-induced neuronal death significantly, underlining the critical role of P2X7R in Tat-mediated neurotoxicity. Our study provides novel insights into astrocyte-mediated neuropathogenesis in HIV-1 infection and a novel target for therapeutic management of neuroAIDS. We investigated the role of P2X7R in Tat-mediated neuroinflammation and neuronal damage. We proposed the following cascade for Tat-mediated CCL2 release from astrocytes: Tat mediates increase in P2X7R expression, which on activation evokes increase in intracellular calcium, which further leads to phosphorylation of ERK1/2 followed by the release of CCL2 from astrocytes. Tat also leads to direct and indirect (mediated via astrocytes) neuronal death that can be abrogated by inhibiting P2X7R. We believe that these finding should provide new insights into the role of astrocytes in HIV-1 Tat-mediated neurotoxicity.
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Hong S, Banks WA. Role of the immune system in HIV-associated neuroinflammation and neurocognitive implications. Brain Behav Immun 2015; 45:1-12. [PMID: 25449672 PMCID: PMC4342286 DOI: 10.1016/j.bbi.2014.10.008] [Citation(s) in RCA: 250] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 10/13/2014] [Accepted: 10/15/2014] [Indexed: 12/16/2022] Open
Abstract
Individuals living with HIV who are optimally treated with combination antiretroviral therapy (cART) can now lead an extended life. In spite of this remarkable survival benefit from viral suppression achieved by cART in peripheral blood, the rate of mild to moderate cognitive impairment remains high. A cognitive decline that includes impairments in attention, learning and executive function is accompanied by increased rates of mood disorders that together adversely impact the daily life of those with chronic HIV infection. The evidence is clear that cells in the brain are infected with HIV that has crossed the blood-brain barrier both as cell-free virus and within infected monocytes and T cells. Viral proteins that circulate in blood can induce brain endothelial cells to release cytokines, invoking another source of neuroinflammation. The difficulty of efficient delivery of cART to the central nervous system (CNS) contributes to elevated viral load in the CNS, resulting in a persistent HIV-associated neurocognitive disorders (HAND). The pathogenesis of HAND is multifaceted, and mounting evidence indicates that immune cells play a major role. HIV-infected monocytes and T cells not only infect brain resident cells upon migration into the CNS but also produce proinflammatory cytokines such as TNF and IL-1ß, which in turn, further activate microglia and astrocytes. These activated brain resident cells, along with perivascular macrophages, are the main contributors to neuroinflammation in HIV infection and release neurotoxic factors such as excitatory amino acids and inflammatory mediators, resulting in neuronal dysfunction and death. Cytokines, which are elevated in the blood of patients with HIV infection, may also contribute to brain inflammation by entering the brain from the blood. Host factors such as aging and co-morbid conditions such as cytomegalovirus co-infection and vascular pathology are important factors that affect the HIV-host immune interactions in HAND pathogenesis. By these diverse mechanisms, HIV-1 induces a neuroinflammatory response that is likely to be a major contributor to the cognitive and behavior changes seen in HIV infection.
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Affiliation(s)
- Suzi Hong
- Department of Psychiatry, University of California San Diego, United States.
| | - William A. Banks
- Geriatric Research Clinical and Education Center, Veterans Affairs Puget Sound Health Care System and Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine
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Cytoplasmic HIV-RNA in monocytes determines microglial activation and neuronal cell death in HIV-associated neurodegeneration. Exp Neurol 2014; 261:685-97. [PMID: 25150097 DOI: 10.1016/j.expneurol.2014.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 07/29/2014] [Accepted: 08/12/2014] [Indexed: 01/08/2023]
Abstract
Despite highly active antiretroviral therapy, HIV-associated neurocognitive disorders (HAND) are still highly prevalent. Direct neurotoxicity of microglia activated by HIV-infected monocytes independent from viral replication may account for this observation. To investigate underlying molecular and viral determinants, human monocytoid cells (U937) transduced with HIV-particles were co-cultured with primary human microglia or astrocytes. Using genetically-engineered HIV-particles key steps of infection were examined. Levels of pro-inflammatory/neurotoxic cytokines were investigated in co-culture supernatants by flow cytometry. Neurotoxicity mediated by the supernatants was analysed using primary cortical rat neurons. To corroborate our findings, cytokine profiles in cerebrospinal fluid (CSF) of neuropsychologically asymptomatic HIV positive (HIV(+)) patients (n=45) were correlated with neurofilament H (NfH) as surrogate of neuronal/axonal degeneration. In contrast to direct exposure of HIV to microglia, only the presence of HIV-transduced monocytoid cells strongly activated human microglia as evidenced by enhanced secretion of CXCL10, CCL5, CCL2, and IL-6 (1.3-7.1-fold; p<0.01) leading to two-fold increased neurotoxicity (p<0.001). In direct comparison, astrocyte activation by HIV-transduced monocytoid cells was limited. Using different mutant HIV-particles we show that the presence of cytoplasmic HIV-RNA in monocytoid cells is the viral determinant for this unique microglial activation pattern and subsequent neuronal cell death; reverse transcription and expression of viral genes were not essential. In CSF of presymptomatic HIV(+) patients, CXCL10, CCL5 and IL-6 were correlated with NfH as surrogate marker of neurodegeneration as well as CSF-pleocytosis. In conclusion, cytosolic viral RNA in monocytes is mandatory for subsequent microglial activation and neurotoxicity; activated astrocytes may augment neuroinflammation. In addition, neuroinflammation and neurodegeneration occur even in preclinical HIV(+) patients and are associated with cytokines regulated in vitro. Our data may aid in the development of biomarkers and glia-directed therapeutic approaches of HAND.
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Dohgu S, Banks WA. Brain pericytes increase the lipopolysaccharide-enhanced transcytosis of HIV-1 free virus across the in vitro blood-brain barrier: evidence for cytokine-mediated pericyte-endothelial cell crosstalk. Fluids Barriers CNS 2013; 10:23. [PMID: 23816186 PMCID: PMC3710206 DOI: 10.1186/2045-8118-10-23] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 06/23/2013] [Indexed: 08/26/2023] Open
Abstract
Background Human immunodeficiency virus-1 (HIV-1) enters the brain by crossing the blood–brain barrier (BBB) as both free virus and within infected immune cells. Previous work showed that activation of the innate immune system with lipopolysaccharide (LPS) enhances free virus transport both in vivo and across monolayer monocultures of brain microvascular endothelial cells (BMECs) in vitro. Methods Here, we used monocultures and co-cultures of brain pericytes and brain endothelial cells to examine the crosstalk between these cell types in mediating the LPS-enhanced permeation of radioactively-labeled HIV-1 (I-HIV) across BMEC monolayers. Results We found that brain pericytes when co-cultured with BMEC monolayers magnified the LPS-enhanced transport of I-HIV without altering transendothelial electrical resistance, indicating that pericytes affected the transcytotic component of HIV-1 permeation. As LPS crosses the BBB poorly if at all, and since pericytes are on the abluminal side of the BBB, we postulated that luminal LPS acts indirectly on pericytes through abluminal secretions from BMECs. Consistent with this, we found that the pattern of secretion of cytokines by pericytes directly exposed to LPS was different than when the pericytes were exposed to the abluminal fluid from LPS-treated BMEC monolayers. Conclusion These results are evidence for a cellular crosstalk in which LPS acts at the luminal surface of the brain endothelial cell, inducing abluminal secretions that stimulate pericytes to release substances that enhance the permeability of the BMEC monolayer to HIV.
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Affiliation(s)
- Shinya Dohgu
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
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Ferrucci A, Nonnemacher MR, Wigdahl B. Extracellular HIV-1 viral protein R affects astrocytic glyceraldehyde 3-phosphate dehydrogenase activity and neuronal survival. J Neurovirol 2013; 19:239-53. [PMID: 23728617 DOI: 10.1007/s13365-013-0170-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 04/30/2013] [Accepted: 05/03/2013] [Indexed: 01/01/2023]
Abstract
Extracellular human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) is a pleiotropic protein accomplishing several functions within the viral life cycle. While Vpr has been described extensively as an intracellular protein, very little is known about its role as an extracellular protein. In fact, HIV-1 Vpr has been detected in the blood, serum, and cerebrospinal fluid of HIV-1-infected patients, with concentrations increasingly higher in late-stage disease. To determine the role exogenous Vpr plays in HIV-associated central nervous system dysfunction, primary human fetal astrocytes were exposed to recombinant Vpr and a time- and dose-dependent decrease was demonstrated in two fundamental intracellular metabolites (adenosine-5'-triphosphate (ATP) and glutathione (GSH)). Additionally, exposure to exogenous Vpr led to increased caspase activity and secretion of proinflammatory cytokines IL-6 and IL-8 and chemoattractants, monocyte chemotactic protein-1, and migration inhibition factor. Extracellular Vpr also dampened the glycolytic pathway through impairment of glyceraldehyde 3-phosphate dehydrogenase activity, causing a decline in the levels of ATP. The reduction in intracellular ATP increased reactive oxygen species buildup, decreasing GSH concentrations, which affected several genes in the oxidative stress pathway. In addition, exposure of the SK-N-SH neuroblastoma cell line to conditioned medium from exogenous Vpr-treated astrocytes decreased synthesis of GSH, leading to their apoptosis. These observations point to a role that Vpr plays in altering astrocytic metabolism and indirectly affecting neuronal survival. We propose a model that may explain some of the neurological damage and therefore neurocognitive impairment observed during the course of HIV-1 disease.
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Affiliation(s)
- Adriano Ferrucci
- School of Biomedical Engineering, Science and Health Systems, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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Renner NA, Sansing HA, Inglis FM, Mehra S, Kaushal D, Lackner AA, Maclean AG. Transient acidification and subsequent proinflammatory cytokine stimulation of astrocytes induce distinct activation phenotypes. J Cell Physiol 2013; 228:1284-94. [PMID: 23154943 DOI: 10.1002/jcp.24283] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 11/02/2012] [Indexed: 01/18/2023]
Abstract
The foot processes of astrocytes cover over 60% of the surface of brain microvascular endothelial cells, regulating tight junction integrity. Retraction of astrocyte foot processes has been postulated to be a key mechanism in pathology. Therefore, movement of an astrocyte in response to a proinflammatory cytokine or even limited retraction of processes would result in leaky junctions between endothelial cells. Astrocytes lie at the gateway to the CNS and are instrumental in controlling leukocyte entry. Cultured astrocytes typically have a polygonal morphology until stimulated. We hypothesized that cultured astrocytes which were induced to stellate would have an activated phenotype compared with polygonal cells. We investigated the activation of astrocytes derived from adult macaques to the cytokine TNF-α under resting and stellated conditions by four parameters: morphology, intermediate filament expression, adhesion, and cytokine secretion. Astrocytes were stellated following transient acidification; resulting in increased expression of GFAP and vimentin. Stellation was accompanied by decreased adhesion that could be recovered with proinflammatory cytokine treatment. Surprisingly, there was decreased secretion of proinflammatory cytokines by stellated astrocytes compared with polygonal cells. These results suggest that astrocytes are capable of multiple phenotypes depending on the stimulus and the order stimuli are applied.
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Affiliation(s)
- Nicole A Renner
- Program in Neuroscience, Tulane University, New Orleans, LA, USA
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Mehla R, Bivalkar-Mehla S, Nagarkatti M, Chauhan A. Programming of neurotoxic cofactor CXCL-10 in HIV-1-associated dementia: abrogation of CXCL-10-induced neuro-glial toxicity in vitro by PKC activator. J Neuroinflammation 2012; 9:239. [PMID: 23078780 PMCID: PMC3533742 DOI: 10.1186/1742-2094-9-239] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 10/08/2012] [Indexed: 01/09/2023] Open
Abstract
Background More than 50% of patients undergoing lifelong suppressive antiviral treatment for HIV-1 infection develop minor HIV-1-associated neurocognitive disorders. Neurological complications during HIV-1 infection are the result of direct neuronal damage by proinflammatory products released from HIV-1-infected or -uninfected activated lymphocytes, monocytes, macrophages, microglia and astrocytes. The specific pro-inflammatory products and their roles in neurotoxicity are far from clear. We investigated proinflammatory cytokines and chemokines in the cerebrospinal fluid (CSF) of HIV-demented (HIV-D) and HIV-nondemented (HIV-ND) patients and studied their affect on neuroglial toxicity. Methods and results Bioplex array showed elevated levels of signatory chemokines or cytokines (IL-6, IFN-γ, CXCL10, MCP-1 and PDGF) in the CSF of HIV-D patients (n = 7) but not in that of HIV-ND patients (n = 7). Among the signatory cytokines and chemokines, CXCL10 was distinctly upregulated in-vitro in HIV-1 (NLENG1)-activated human fetal astrocytes, HIV-1 (Ba-L)-infected macrophages, and HIV-1 (NLENG1)-infected lymphocytes. Virus-infected macrophages also had increased levels of TNF-α. Consistently, human fetal astrocytes treated with HIV-1 and TNF-α induced the signatory molecules. CXCL10 in combination with HIV-1 synergistically enhanced neuronal toxicity and showed chemotactic activity (~ 40 fold) for activated peripheral blood mononuclear cells (PBMC), suggesting the intersection of signaling events imparted by HIV-1 and CXCL10 after binding to their respective surface receptors, CXCR4 and CXCR3, on neurons. Blocking CXCR3 and its downstream MAP kinase (MAPK) signaling pathway suppressed combined CXCL10 and HIV-1-induced neurotoxicity. Bryostatin, a PKC modulator and suppressor of CXCR4, conferred neuroprotection against combined insult with HIV-1 and CXCL10. Bryostatin also suppressed HIV-1 and CXCL10-induced PBMC chemotaxis. Although, therapeutic targeting of chemokines in brain may have adverse consequences on the host, current findings and earlier evidence suggest that CXCL10 could strongly impede neuroinflammation. Conclusion We have demonstrated induction of CXCL10 and other chemokines/cytokines during HIV-1 infection in the brain, as well as synergism of CXCL10 with HIV-1 in neuronal toxicity, which was dampened by bryostatin.
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Affiliation(s)
- Rajeev Mehla
- Department of Pathology, Microbiology & Immunology, University of South Carolina, School of Medicine, Columbia, SC 29209, USA
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De Chiara G, Marcocci ME, Sgarbanti R, Civitelli L, Ripoli C, Piacentini R, Garaci E, Grassi C, Palamara AT. Infectious agents and neurodegeneration. Mol Neurobiol 2012; 46:614-38. [PMID: 22899188 PMCID: PMC3496540 DOI: 10.1007/s12035-012-8320-7] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 07/31/2012] [Indexed: 12/19/2022]
Abstract
A growing body of epidemiologic and experimental data point to chronic bacterial and viral infections as possible risk factors for neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. Infections of the central nervous system, especially those characterized by a chronic progressive course, may produce multiple damage in infected and neighbouring cells. The activation of inflammatory processes and host immune responses cause chronic damage resulting in alterations of neuronal function and viability, but different pathogens can also directly trigger neurotoxic pathways. Indeed, viral and microbial agents have been reported to produce molecular hallmarks of neurodegeneration, such as the production and deposit of misfolded protein aggregates, oxidative stress, deficient autophagic processes, synaptopathies and neuronal death. These effects may act in synergy with other recognized risk factors, such as aging, concomitant metabolic diseases and the host’s specific genetic signature. This review will focus on the contribution given to neurodegeneration by herpes simplex type-1, human immunodeficiency and influenza viruses, and by Chlamydia pneumoniae.
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Affiliation(s)
- Giovanna De Chiara
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy.
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Sagar D, Foss C, El Baz R, Pomper MG, Khan ZK, Jain P. Mechanisms of dendritic cell trafficking across the blood-brain barrier. J Neuroimmune Pharmacol 2012; 7:74-94. [PMID: 21822588 PMCID: PMC3276728 DOI: 10.1007/s11481-011-9302-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 07/25/2011] [Indexed: 12/14/2022]
Abstract
Although the central nervous system (CNS) is considered to be an immunoprivileged site, it is susceptible to a host of autoimmune as well as neuroinflammatory disorders owing to recruitment of immune cells across the blood-brain barrier into perivascular and parenchymal spaces. Dendritic cells (DCs), which are involved in both primary and secondary immune responses, are the most potent immune cells in terms of antigen uptake and processing as well as presentation to T cells. In light of the emerging importance of DC traficking into the CNS, these cells represent good candidates for targeted immunotherapy against various neuroinflammatory diseases. This review focuses on potential physiological events and receptor interactions between DCs and the microvascular endothelial cells of the brain as they transmigrate into the CNS during degeneration and injury. A clear understanding of the underlying mechanisms involved in DC migration may advance the development of new therapies that manipulate these mechanistic properties via pharmacologic intervention. Furthermore, therapeutic validation should be in concurrence with the molecular imaging techniques that can detect migration of these cells in vivo. Since the use of noninvasive methods to image migration of DCs into CNS has barely been explored, we highlighted potential molecular imaging techniques to achieve this goal. Overall, information provided will bring this important leukocyte population to the forefront as key players in the immune cascade in the light of the emerging contribution of DCs to CNS health and disease.
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Affiliation(s)
- Divya Sagar
- Drexel Institute for Biotechnology and Virology Research, and Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Catherine Foss
- Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA
| | - Rasha El Baz
- Drexel Institute for Biotechnology and Virology Research, and Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Martin G. Pomper
- Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA
| | - Zafar K. Khan
- Drexel Institute for Biotechnology and Virology Research, and Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Pooja Jain
- Drexel Institute for Biotechnology and Virology Research, and Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
- Department of Microbiology & Immunology, Drexel Institute for Biotechnology & Virology Research, Drexel University College of Medicine, 3805 Old Easton Road, Doylestown, PA 18902, USA
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Abstract
PURPOSE OF REVIEW Macrophages play an important role in HIV-1 pathogenesis and contribute to the establishment of the viral reservoir responsible for continuous virus production. This review will discuss new insights into HIV-1 infection in macrophages and the effect of infection on immune function and pathology. RECENT FINDINGS New cellular factors interacting with various steps of the HIV-1 replication cycle, such as entry, integration, transcription, and assembly of new viral progeny, have been identified. Cellular and viral microRNAs have been shown to regulate virus replication, promote viral latency, and prolong cell survival. Interference with innate immune functions, like phagocytosis, autophagy, cytokine production, and T-cell activation by HIV-1 has been found to contribute to virus replication and latency. Growing evidence indicates an important role of infected macrophages in a variety of HIV-1-associated diseases, including neurocognitive disorders. SUMMARY Under combined antiretroviral therapy (cART), HIV-1 continues to persist in macrophages. Better understanding of HIV-1 infection in macrophages may lead to new adjunctive therapies to improve cART, specifically targeting the viral reservoir and ameliorating tissue-specific diseases.
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Deslauriers AM, Afkhami-Goli A, Paul AM, Bhat RK, Acharjee S, Ellestad KK, Noorbakhsh F, Michalak M, Power C. Neuroinflammation and endoplasmic reticulum stress are coregulated by crocin to prevent demyelination and neurodegeneration. THE JOURNAL OF IMMUNOLOGY 2011; 187:4788-99. [PMID: 21964030 DOI: 10.4049/jimmunol.1004111] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Endoplasmic reticulum (ER) stress is a homeostatic mechanism, which is used by cells to adapt to intercellular and intracellular changes. Moreover, ER stress is closely linked to inflammatory pathways. We hypothesized that ER stress is an integral component of neuroinflammation and contributes to the development of neurological diseases. In autopsied brain specimens from multiple sclerosis (MS) and non-MS patients, XBP-1 spliced variant (XBP-1/s) was increased in MS brains (p < 0.05) and was correlated with the expression of the human endogenous retrovirus-W envelope transcript, which encodes the glycoprotein, Syncytin-1 (p < 0.05). In primary human fetal astrocytes transfected with a Syncytin-1-expressing plasmid, XBP-1/s, BiP, and NOS2 were induced, which was suppressed by crocin treatment (p < 0.05). Crocin also protected oligodendrocytes exposed to cytotoxic supernatants derived from Syncytin-1-expressing astrocytes (p < 0.05) and NO-mediated oligodendrocytotoxicity (p < 0.05). During experimental autoimmune encephalomyelitis (EAE), the transcript levels of the ER stress genes XBP-1/s, BiP, PERK, and CHOP were increased in diseased spinal cords compared with healthy littermates (p < 0.05), although CHOP expression was not involved in the EAE disease phenotype. Daily treatment with crocin starting on day 7 post-EAE induction suppressed ER stress and inflammatory gene expression in spinal cords (p < 0.05), which was accompanied by preserved myelination and axonal density, together with reduced T cell infiltration and macrophage activation. EAE-associated neurobehavioral deficits were also ameliorated by crocin treatment (p < 0.05). These findings underscored the convergent roles of pathogenic ER stress and immune pathways in neuroinflammatory disease and point to potential therapeutic applications for crocin.
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Affiliation(s)
- André M Deslauriers
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2S2, Canada
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Abstract
HIV can infect the brain and impair central nervous system (CNS) function. Combination antiretroviral therapy (cART) has not eradicated CNS complications. HIV-associated neurocognitive disorders (HAND) remain common despite cART, although attenuated in severity. This may result from a combination of factors including inadequate treatment of HIV reservoirs such as circulating monocytes and glia, decreased effectiveness of cART in CNS, concurrent illnesses, stimulant use, and factors associated with prescribed drugs, including antiretrovirals. This review highlights recent investigations of HIV-related CNS injury with emphasis on cART-era neuropathological mechanisms in the context of both US and international settings.
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