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Thompson LJP, Genovese J, Hong Z, Singh MV, Singh VB. HIV-Associated Neurocognitive Disorder: A Look into Cellular and Molecular Pathology. Int J Mol Sci 2024; 25:4697. [PMID: 38731913 PMCID: PMC11083163 DOI: 10.3390/ijms25094697] [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: 03/25/2024] [Revised: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Despite combined antiretroviral therapy (cART) limiting HIV replication to undetectable levels in the blood, people living with HIV continue to experience HIV-associated neurocognitive disorder (HAND). HAND is associated with neurocognitive impairment, including motor impairment, and memory loss. HIV has been detected in the brain within 8 days of estimated exposure and the mechanisms for this early entry are being actively studied. Once having entered into the central nervous system (CNS), HIV degrades the blood-brain barrier through the production of its gp120 and Tat proteins. These proteins are directly toxic to endothelial cells and neurons, and propagate inflammatory cytokines by the activation of immune cells and dysregulation of tight junction proteins. The BBB breakdown is associated with the progression of neurocognitive disease. One of the main hurdles for treatment for HAND is the latent pool of cells, which are insensitive to cART and prolong inflammation by harboring the provirus in long-lived cells that can reactivate, causing damage. Multiple strategies are being studied to combat the latent pool and HAND; however, clinically, these approaches have been insufficient and require further revisions. The goal of this paper is to aggregate the known mechanisms and challenges associated with HAND.
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Affiliation(s)
| | - Jessica Genovese
- Department of Life Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, USA
| | - Zhenzi Hong
- Department of Life Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, USA
| | - Meera Vir Singh
- Department of Neurology, University of Rochester, Rochester, NY 14642, USA
| | - Vir Bahadur Singh
- Department of Life Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, USA
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Yuan Z, Huang Y, Sadikot RT. Long Noncoding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 Promotes HIV-1 Replication through Modulating microRNAs in Macrophages. J Virol 2023; 97:e0005323. [PMID: 37255470 PMCID: PMC10308927 DOI: 10.1128/jvi.00053-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/11/2023] [Indexed: 06/01/2023] Open
Abstract
Macrophages can serve as a reservoir for human immunodeficiency-1 (HIV-1) virus in host cells, constituting a barrier to eradication, even in patients who are receiving antiretroviral therapy. Although many noncoding RNAs have been characterized as regulators in HIV-1/AIDS-induced immune response and pathogenesis, only a few long noncoding RNAs (lncRNAs) have demonstrated a close association with HIV-1 replication, and the molecular mechanisms remain unknown. In this study, we investigated how lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), related microRNAs, and key inflammatory genes alter HIV-1 replication in macrophages. Our data show that HIV-1 infection modulates the expression of miR-155 and miR-150-5p in a time-dependent manner, which is regulated by MALAT1. MALAT1 induced suppressor of cytokine signaling 1 (SOCS1) expression by sponging miR-150-5p in HIV-1-infected macrophages and stimulated inflammatory mediators triggering receptor expressed on myeloid cells/cold inducible RNA binding protein (TREM 1/CIRP) ligand/receptor. The RNA immunoprecipitation (RIP) assay validated the direct interaction within the MALAT1/miR-150-5p/SOCS1 axis. HIV-1 infection-mediated upregulation of MALAT1, SOCS1, and HIV-1 Gag was attenuated by SN50 (an NF-кB p50 inhibitor). MALAT1 antisense oligonucleotides (ASOs) suppressed HIV-1 p24 production and HIV-1 Gag gene expression and decreased expression of miR-155 and SOCS1, as well as the production of proinflammatory cytokines by HIV-1-infected macrophages. In conclusion, HIV-1 infection induces MALAT1, which attenuates miR-150-5p expression and increases SOCS1 expression, promoting HIV-1 replication and reactivation. These data provide new insights into how MALAT1 alters the macrophage microenvironment and subsequently promotes viral replication and suggest a potential role for targeting MALAT1 as a therapeutic approach to eliminate HIV-1 reservoirs. IMPORTANCE Viral reservoirs constitute an obstacle to curing HIV-1 diseases, despite antiretroviral therapy. Macrophages serve as viral reservoirs in HIV infection by promoting long-term replication and latency. Recent studies have shown that lncRNAs can modulate virus-host interactions, but the underlying mechanisms are not fully understood. In this study, we demonstrate how lncRNA MALAT1 contributes to HIV-1 replication through modulation of the miR-150/SOCS1 axis in human macrophages. Our findings have the potential to identify new therapies for eliminating HIV-1 reservoirs in immune cells.
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Affiliation(s)
- Zhihong Yuan
- VA Nebraska Western Iowa Health Care System, Omaha, Nebraska, USA
- Division of Pulmonary, Critical Care & Sleep, Department of Internal Medicine, University of 0Nebraska Medical Center, Omaha, Nebraska, USA
| | - Yunlong Huang
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Ruxana T. Sadikot
- VA Nebraska Western Iowa Health Care System, Omaha, Nebraska, USA
- Division of Pulmonary, Critical Care & Sleep, Department of Internal Medicine, University of 0Nebraska Medical Center, Omaha, Nebraska, USA
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Du Y, Yan B. Ocular immune privilege and retinal pigment epithelial cells. J Leukoc Biol 2023; 113:288-304. [PMID: 36805720 DOI: 10.1093/jleuko/qiac016] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Indexed: 02/04/2023] Open
Abstract
The ocular tissue microenvironment is immune-privileged and uses multiple immunosuppressive mechanisms to prevent the induction of inflammation. The retinal pigment epithelium plays an essential role in ocular immune privilege. In addition to serving as a blood barrier separating the fenestrated choriocapillaris from the retina, the retinal pigment epithelium is a source of immunosuppressive cytokines and membrane-bound negative regulators that modulate the activity of immune cells within the retina. This article reviews the current understanding of how retinal pigment epithelium cells mediate immune regulation, focusing on the changes under pathologic conditions.
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Affiliation(s)
- Yuxiang Du
- Institute of Precision Medicine, Jining Medical University, No. 133, Hehua Road, Taibaihu New District, Jining, Shandong 272067, People's Republic of China
| | - Bo Yan
- Institute of Precision Medicine, Jining Medical University, No. 133, Hehua Road, Taibaihu New District, Jining, Shandong 272067, People's Republic of China
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Kaddour H, McDew-White M, Madeira MM, Tranquille MA, Tsirka SE, Mohan M, Okeoma CM. Chronic delta-9-tetrahydrocannabinol (THC) treatment counteracts SIV-induced modulation of proinflammatory microRNA cargo in basal ganglia-derived extracellular vesicles. J Neuroinflammation 2022; 19:225. [PMID: 36096938 PMCID: PMC9469539 DOI: 10.1186/s12974-022-02586-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 08/24/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Early invasion of the central nervous system (CNS) by human immunodeficiency virus (HIV) (Gray et al. in Brain Pathol 6:1-15, 1996; An et al. in Ann Neurol 40:611-6172, 1996), results in neuroinflammation, potentially through extracellular vesicles (EVs) and their micro RNAs (miRNA) cargoes (Sharma et al. in FASEB J 32:5174-5185, 2018; Hu et al. in Cell Death Dis 3:e381, 2012). Although the basal ganglia (BG) is a major target and reservoir of HIV in the CNS (Chaganti et al. in Aids 33:1843-1852, 2019; Mintzopoulos et al. in Magn Reson Med 81:2896-2904, 2019), whether BG produces EVs and the effect of HIV and/or the phytocannabinoid-delta-9-tetrahydrocannabinol (THC) on BG-EVs and HIV neuropathogenesis remain unknown. METHODS We used the simian immunodeficiency virus (SIV) model of HIV and THC treatment in rhesus macaques (Molina et al. in AIDS Res Hum Retroviruses 27:585-592, 2011) to demonstrate for the first time that BG contains EVs (BG-EVs), and that BG-EVs cargo and function are modulated by SIV and THC. We also used primary astrocytes from the brains of wild type (WT) and CX3CR1+/GFP mice to investigate the significance of BG-EVs in CNS cells. RESULTS Significant changes in BG-EV-associated miRNA specific to SIV infection and THC treatment were observed. BG-EVs from SIV-infected rhesus macaques (SIV EVs) contained 11 significantly downregulated miRNAs. Remarkably, intervention with THC led to significant upregulation of 37 miRNAs in BG-EVs (SIV-THC EVs). Most of these miRNAs are predicted to regulate pathways related to inflammation/immune regulation, TLR signaling, Neurotrophin TRK receptor signaling, and cell death/response. BG-EVs activated WT and CX3CR1+/GFP astrocytes and altered the expression of CD40, TNFα, MMP-2, and MMP-2 gene products in primary mouse astrocytes in an EV and CX3CR1 dependent manners. CONCLUSIONS Our findings reveal a role for BG-EVs as a vehicle with potential to disseminate HIV- and THC-induced changes within the CNS.
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Affiliation(s)
- Hussein Kaddour
- Department of Pharmacology, Stony Brook University Renaissance School of Medicine, Stony Brook, NY 11794-8651 USA
- Present Address: Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591 USA
| | - Marina McDew-White
- Host Pathogen Interaction Program, Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX 78227-5302 USA
| | - Miguel M. Madeira
- Department of Pharmacology, Stony Brook University Renaissance School of Medicine, Stony Brook, NY 11794-8651 USA
| | - Malik A. Tranquille
- Department of Pharmacology, Stony Brook University Renaissance School of Medicine, Stony Brook, NY 11794-8651 USA
| | - Stella E. Tsirka
- Department of Pharmacology, Stony Brook University Renaissance School of Medicine, Stony Brook, NY 11794-8651 USA
| | - Mahesh Mohan
- Host Pathogen Interaction Program, Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX 78227-5302 USA
| | - Chioma M. Okeoma
- Department of Pharmacology, Stony Brook University Renaissance School of Medicine, Stony Brook, NY 11794-8651 USA
- Department of Pathology, Microbiology, and Immunology, New York Medical College, Valhalla, NY 10595-1524 USA
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Bhusal A, Rahman MH, Suk K. Hypothalamic inflammation in metabolic disorders and aging. Cell Mol Life Sci 2021; 79:32. [PMID: 34910246 PMCID: PMC11071926 DOI: 10.1007/s00018-021-04019-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/01/2021] [Accepted: 10/29/2021] [Indexed: 12/15/2022]
Abstract
The hypothalamus is a critical brain region for the regulation of energy homeostasis. Over the years, studies on energy metabolism primarily focused on the neuronal component of the hypothalamus. Studies have recently uncovered the vital role of glial cells as an additional player in energy balance regulation. However, their inflammatory activation under metabolic stress condition contributes to various metabolic diseases. The recruitment of monocytes and macrophages in the hypothalamus helps sustain such inflammation and worsens the disease state. Neurons were found to actively participate in hypothalamic inflammatory response by transmitting signals to the surrounding non-neuronal cells. This activation of different cell types in the hypothalamus leads to chronic, low-grade inflammation, impairing energy balance and contributing to defective feeding habits, thermogenesis, and insulin and leptin signaling, eventually leading to metabolic disorders (i.e., diabetes, obesity, and hypertension). The hypothalamus is also responsible for the causation of systemic aging under metabolic stress. A better understanding of the multiple factors contributing to hypothalamic inflammation, the role of the different hypothalamic cells, and their crosstalks may help identify new therapeutic targets. In this review, we focus on the role of glial cells in establishing a cause-effect relationship between hypothalamic inflammation and the development of metabolic diseases. We also cover the role of other cell types and discuss the possibilities and challenges of targeting hypothalamic inflammation as a valid therapeutic approach.
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Affiliation(s)
- Anup Bhusal
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
| | - Md Habibur Rahman
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
- Division of Endocrinology, Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08901, USA
| | - Kyoungho Suk
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
- Brain Science and Engineering Institute, Kyungpook National University, Daegu, 41944, Republic of Korea.
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Borrajo A, Spuch C, Penedo MA, Olivares JM, Agís-Balboa RC. Important role of microglia in HIV-1 associated neurocognitive disorders and the molecular pathways implicated in its pathogenesis. Ann Med 2021; 53:43-69. [PMID: 32841065 PMCID: PMC7877929 DOI: 10.1080/07853890.2020.1814962] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 08/13/2020] [Indexed: 12/11/2022] Open
Abstract
The development of effective combined anti-retroviral therapy (cART) led to a significant reduction in the death rate associated with human immunodeficiency virus type 1 (HIV-1) infection. However, recent studies indicate that considerably more than 50% of all HIV-1 infected patients develop HIV-1-associated neurocognitive disorder (HAND). Microglia are the foremost cells infected by HIV-1 in the central nervous system (CNS), and so, are also likely to contribute to the neurotoxicity observed in HAND. The activation of microglia induces the release of pro-inflammatory markers and altered secretion of cytokines, chemokines, secondary messengers, and reactive oxygen species (ROS) which activate signalling pathways that initiate neuroinflammation. In turn, ROS and inflammation also play critical roles in HAND. However, more efforts are required to understand the physiology of microglia and the processes involved in their activation in order to better understand the how HIV-1-infected microglia are involved in the development of HAND. In this review, we summarize the current state of knowledge about the involvement of oxidative stress mechanisms and role of HIV-induced ROS in the development of HAND. We also examine the academic literature regarding crucial HIV-1 pathogenicity factors implicated in neurotoxicity and inflammation in order to identify molecular pathways that could serve as potential therapeutic targets for treatment of this disease. KEY MESSAGES Neuroinflammation and excitotoxicity mechanisms are crucial in the pathogenesis of HAND. CNS infiltration by HIV-1 and immune cells through the blood brain barrier is a key process involved in the pathogenicity of HAND. Factors including calcium dysregulation and autophagy are the main challenges involved in HAND.
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Affiliation(s)
- A. Borrajo
- Department of Microbiology and Parasitology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Roma, Italy
| | - C. Spuch
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur)-Área Sanitaria de Vigo, SERGAS-UVigo, CIBERSAM, Vigo, Spain
| | - M. A. Penedo
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur)-Área Sanitaria de Vigo, SERGAS-UVigo, CIBERSAM, Vigo, Spain
| | - J. M. Olivares
- Department of Psychiatry, Área Sanitaria de Vigo, Vigo, Spain
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur)-Área Sanitaria de Vigo, SERGAS-UVigo, CIBERSAM, Vigo, Spain
| | - R. C. Agís-Balboa
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur)-Área Sanitaria de Vigo, SERGAS-UVigo, CIBERSAM, Vigo, Spain
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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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8
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Kulczyńska-Przybik A, Słowik A, Mroczko P, Borawski B, Groblewska M, Borawska R, Mroczko B. Cerebrospinal Fluid and Blood CX3CL1 as a Potential Biomarker in Early Diagnosis and Prognosis of Dementia. Curr Alzheimer Res 2020; 17:709-721. [PMID: 33167838 DOI: 10.2174/1567205017666201109095657] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 09/11/2020] [Accepted: 10/13/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND A growing body of evidence highlights the crucial role of neuroinflammation and chemokine involvement in cognitive impairment pathophysiology. Fractalkine (CX3CL1) appears to be a relevant causative factor in the development of dementia, particularly at the early stages of the disease. However, limited data are available on the levels of CX3CL1 in the cerebrospinal fluid (CSF) and blood. Additionally, to date, its utility as a biomarker for MCI or AD has not been studied. OBJECTIVE The aim of the present study was to evaluate the clinical utility of CX3CL1 in the early diagnosis of cognitive impairment. We also compared the diagnostic usefulness of CX3CL1 with other biomarkers associated with neuroinflammation. METHODS A total of 60 patients with cognitive impairment, including 42 patients with AD and 18 subjects with MCI, as well as 20 cognitively healthy controls were enrolled in the study. CSF and blood concentrations of CX3CL1, CCL-2, and YKL-40 were measured by ELISA. RESULTS Significantly higher CSF and blood concentrations of CX3CL1 were observed in MCI and AD patients compared to older individuals without cognitive impairment. The increase in the levels of CX3CL1 and YKL-40 in non-demented subjects was associated with MCI. The area under the ROC curve for CX3CL1 in MCI subjects was larger in comparison to classical AD markers. CONCLUSION Presented results indicate a crucial role of CX3CL1 in the pathology of cognitive impairment and the potential usefulness of this protein in the early diagnosis of MCI and AD.
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Affiliation(s)
| | - Agnieszka Słowik
- Department of Neurology, Jagiellonian University, Krakow, Poland
| | - Piotr Mroczko
- Department of Criminal Law and Criminology, Faculty of Law, University of Bialystok, Bialystok, Poland
| | - Bartłomiej Borawski
- Department of Neurodegeneration Diagnostics, Medical University of Bialystok, Waszyngtona, Bialystok, Poland
| | - Magdalena Groblewska
- Department of Biochemical Diagnostics, University Hospital in Bialystok, Bialystok, Poland
| | - Renata Borawska
- Department of Neurodegeneration Diagnostics, Medical University of Bialystok, Waszyngtona, Bialystok, Poland
| | - Barbara Mroczko
- Department of Neurodegeneration Diagnostics, Medical University of Bialystok, Waszyngtona, Bialystok, Poland.,Department of Biochemical Diagnostics, University Hospital in Bialystok, Bialystok, Poland.,Department of Biochemical Diagnostics, Medical University of Bialystok, Bialystok, Poland
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9
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Sénécal V, Barat C, Tremblay MJ. The delicate balance between neurotoxicity and neuroprotection in the context of HIV-1 infection. Glia 2020; 69:255-280. [PMID: 32910482 DOI: 10.1002/glia.23904] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 08/15/2020] [Accepted: 08/16/2020] [Indexed: 12/17/2022]
Abstract
Human immunodeficiency virus type-1 (HIV-1) causes a spectrum of neurological impairments, termed HIV-associated neurocognitive disorder (HAND), following the infiltration of infected cells into the brain. Even though the implementation of antiretroviral therapy reduced the systemic viral load, the prevalence of HAND remains unchanged and infected patients develop persisting neurological disturbances affecting their quality of life. As a result, HAND have gained importance in basic and clinical researches, warranting the need of developing new adjunctive treatments. Nonetheless, a better understanding of the molecular and cellular mechanisms remains necessary. Several studies consolidated their efforts into elucidating the neurotoxic signaling leading to HAND including the deleterious actions of HIV-1 viral proteins and inflammatory mediators. However, the scope of these studies is not sufficient to address all the complexity related to HAND development. Fewer studies focused on an altered neuroprotective capacity of the brain to respond to HIV-1 infection. Neurotrophic factors are endogenous polyproteins involved in neuronal survival, synaptic plasticity, and neurogenesis. Any defects in the processing or production of these crucial factors might compose a risk factor rendering the brain more vulnerable to neuronal damages. Due to their essential roles, they have been investigated for their diverse interplays with HIV-1 infection. In this review, we present a complete description of the neurotrophic factors involved in HAND. We discuss emerging concepts for their therapeutic applications and summarize the complex mechanisms that down-regulate their production in favor of a neurotoxic environment. For certain factors, we finally address opposing roles that rather lead to increased inflammation.
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Affiliation(s)
- Vincent Sénécal
- Axe des Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Pavillon CHUL, Québec, Quebec, Canada
| | - Corinne Barat
- Axe des Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Pavillon CHUL, Québec, Quebec, Canada
| | - Michel J Tremblay
- Axe des Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec-Université Laval, Pavillon CHUL, Québec, Quebec, Canada.,Département de Microbiologie-infectiologie et immunologie, Faculté de Médecine, Université Laval, Québec, Quebec, Canada
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Microglia Mediate HIV-1 gp120-Induced Synaptic Degeneration in Spinal Pain Neural Circuits. J Neurosci 2019; 39:8408-8421. [PMID: 31471472 DOI: 10.1523/jneurosci.2851-18.2019] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 02/07/2023] Open
Abstract
HIV-1 infection of the nervous system causes various neurological diseases, and synaptic degeneration is likely a critical step in the neuropathogenesis. Our prior studies revealed a significant decrease of synaptic protein, specifically in the spinal dorsal horn of patients with HIV-1 in whom pain developed, suggesting a potential contribution of synaptic degeneration to the pathogenesis of HIV-associated pain. However, the mechanism by which HIV-1 causes the spinal synaptic degeneration is unclear. Here, we identified a critical role of microglia in the synaptic degeneration. In primary cortical cultures (day in vitro 14) and spinal cords of 3- to 5-month-old mice (both sexes), microglial ablation inhibited gp120-induced synapse decrease. Fractalkine (FKN), a microglia activation chemokine specifically expressed in neurons, was upregulated by gp120, and knockout of the FKN receptor CX3CR1, which is predominantly expressed in microglia, protected synapses from gp120-induced toxicity. These results indicate that the neuron-to-microglia intercellular FKN/CX3CR1 signaling plays a role in gp120-induced synaptic degeneration. To elucidate the mechanism controlling this intercellular signaling, we tested the role of the Wnt/β-catenin pathway in regulating FKN expression. Inhibition of Wnt/β-catenin signaling blocked both gp120-induced FKN upregulation and synaptic degeneration, and gp120 stimulated Wnt/β-catenin-regulated FKN expression via NMDA receptors (NMDARs). Furthermore, NMDAR antagonist APV, Wnt/β-catenin signaling suppressor DKK1, or knockout of CX3CR1 alleviated gp120-induced mechanical allodynia in mice, suggesting a critical contribution of the Wnt/β-catenin/FKN/CX3R1 pathway to gp120-induced pain. These findings collectively suggest that HIV-1 gp120 induces synaptic degeneration in the spinal pain neural circuit by activating microglia via Wnt3a/β-catenin-regulated FKN expression in neurons.SIGNIFICANCE STATEMENT Synaptic degeneration develops in the spinal cord dorsal horn of HIV patients with chronic pain, but the patients without the pain disorder do not show this neuropathology, indicating a pathogenic contribution of the synaptic degeneration to the development of HIV-associated pain. However, the mechanism underlying the synaptic degeneration is unclear. We report here that HIV-1 gp120, a neurotoxic protein that is specifically associated with the manifestation of pain in HIV patients, induces synapse loss via microglia. Further studies elucidate that gp120 activates microglia by stimulating Wnt/β-catenin-regulated fractalkine in neuron. The results demonstrate a critical role of microglia in the pathogenesis of HIV-associated synaptic degeneration in the spinal pain neural circuit.
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11
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Zhao R, Li Y, Gorantla S, Poluektova LY, Lin H, Gao F, Wang H, Zhao J, Zheng JC, Huang Y. Small molecule ONC201 inhibits HIV-1 replication in macrophages via FOXO3a and TRAIL. Antiviral Res 2019; 168:134-145. [PMID: 31158413 DOI: 10.1016/j.antiviral.2019.05.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 01/01/2023]
Abstract
Despite the success of antiretroviral therapy (ART), eradication of HIV-1 from brain reservoirs remains elusive. HIV-1 brain reservoirs include perivascular macrophages that are behind the blood-brain barrier and difficult to access by ART. Macrophages express transcription factor FOXO3a and the TNF superfamily cytokine TRAIL, which are known to target HIV-1-infected macrophages for viral inhibition. ONC201 is a novel and potent FOXO3a activator capable of inducing TRAIL. It can cross the blood-brain barrier, and has shown antitumor effects in clinical trials. We hypothesized that activation of FOXO3a/TRAIL by ONC201 will inhibit HIV-1 replication in macrophages. Using primary human monocyte-derived macrophages, we demonstrated that ONC201 dose-dependently decreased replication levels of both HIV-1 laboratory strain and primary strains as determined by HIV-1 reverse transcriptase activity assay. Consistent with data on HIV-1 replication, ONC201 also reduced intracellular and extracellular p24, viral RNA, and integrated HIV-1 DNA in infected macrophages. Blocking TRAIL or knockdown of FOXO3a with siRNA reversed ONC201-mediated HIV-1 suppression, suggesting that ONC201 inhibits HIV-1 through FOXO3a and TRAIL. The anti-HIV-1 effect of ONC201 was further validated in vivo in NOD/scid-IL-2Rgcnull mice. After intracranial injection of HIV-1-infected macrophages into the basal ganglia, we treated the mice daily with ONC201 through intraperitoneal injection for six days. ONC201 significantly decreased p24 levels in both the macrophages and the brain tissues, suggesting that ONC201 suppresses HIV-1 in vivo. Therefore, ONC201 can be a promising drug candidate to combat persistent HIV-1 infection in the brain.
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Affiliation(s)
- Runze Zhao
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Yuju Li
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States; Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Santhi Gorantla
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Larisa Y Poluektova
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Hai Lin
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States; Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Fengtong Gao
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Hongyun Wang
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Jeffrey Zhao
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Jialin C Zheng
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States; Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China.
| | - Yunlong Huang
- Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States; Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China.
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12
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Abstract
Human immunodeficiency virus (HIV) infection induces neuronal injuries, with almost 50% of infected individuals developing HIV-associated neurocognitive disorders (HAND). Although highly activate antiretroviral therapy (HAART) has significantly reduced the incidence of severe dementia, the overall prevalence of HAND remains high. Synaptic degeneration is emerging as one of the most relevant neuropathologies associate with HAND. Previous studies have reported critical roles of viral proteins and inflammatory responses in this pathogenesis. Infected cells, including macrophages, microglia and astrocytes, may release viral proteins and other neurotoxins to stimulate neurons and cause excessive calcium influx, overproduction of free radicals and disruption of neurotransmitter hemostasis. The dysregulation of neural circuits likely leads to synaptic damage and loss. Identification of the specific mechanism of the synaptic degeneration may facilitate the development of effective therapeutic approaches to treat HAND.
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Affiliation(s)
- Wenjuan Ru
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Shao-Jun Tang
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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13
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Guo L, Lu X, Wang Y, Bao C, Chen S. Elevated levels of soluble fractalkine and increased expression of CX3CR1 in neuropsychiatric systemic lupus erythematosus. Exp Ther Med 2017; 14:3153-3158. [PMID: 28912865 DOI: 10.3892/etm.2017.4862] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 08/23/2016] [Indexed: 11/05/2022] Open
Abstract
The aim of the present study was to determine the levels of soluble fractalkine (sFKN) and expression of CX3CR1 in neuropsychiatric systemic lupus erythematosus (NPSLE). Disease activity of SLE was assessed using the SLE Disease Activity Index (SLEDAI). The mRNA expression levels of CX3CR1 and FKN were quantified using reverse transcription-quantitative polymerase chain reaction. Levels of sFKN in the serum and cerebrospinal fluid (CSF) were measured using enzyme-linked immunosorbent assays. The mRNA expression levels of CX3CR1 in peripheral blood mononuclear cells from patients with NPSLE, non-NPSLE and Behcet's disease were significantly higher than that of rheumatoid arthritis and healthy persons. Levels of sFKN in the serum and CSF of cells with diffuse NPSLE (DNPSLE) were significantly higher than those of focal NPSLE (FNPSLE) cells. Serum levels of sFKN were higher in patients with NPSLE or non-NPSLE than heathy persons. sFKN in CSF were significantly higher in DNPSLE than non-NPSLE cells, but there were no significant difference between FNPSLE and control. Treatment reduced sFKN in serum and CSF in patients with NPSLE. There was significant correlation between sFKN in the serum of patients with SLE and the SLEDAI. sFKN levels were correlated with IgG in CSF from patients with NPSLE. The mRNA expression levels of CX3CR1 in the brain tissue of lupus mice were significantly higher than normal mice; however, the mRNA expression of FKN was lower than normal mice. These results suggest that sFKN and CX3CR1 may be involved in vasculitis and SLE, particularly in DNPSLE, which may occur by damaging the blood-brain barrier or recruiting expression microglial cells of CX3CR1. Additionally, sFKN appears to be a serological marker in patients with SLE, and may be useful for the diagnosis and treatment of NPSLE.
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Affiliation(s)
- Ling Guo
- Department of Rheumatology, Dongying People's Hospital, Dongying, Shandong 257091, P.R. China
| | - Xiaoye Lu
- Department of Emergency, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200001, P.R. China
| | - Yuan Wang
- Department of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200001, P.R. China
| | - Chunde Bao
- Department of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200001, P.R. China
| | - Shunle Chen
- Department of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200001, P.R. China
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14
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Saylor D, Dickens AM, Sacktor N, Haughey N, Slusher B, Pletnikov M, Mankowski JL, Brown A, Volsky DJ, McArthur JC. HIV-associated neurocognitive disorder--pathogenesis and prospects for treatment. Nat Rev Neurol 2016; 12:234-48. [PMID: 26965674 DOI: 10.1038/nrneurol.2016.27] [Citation(s) in RCA: 546] [Impact Index Per Article: 68.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the past two decades, several advancements have improved the care of HIV-infected individuals. Most importantly, the development and deployment of combination antiretroviral therapy (CART) has resulted in a dramatic decline in the rate of deaths from AIDS, so that people living with HIV today have nearly normal life expectancies if treated with CART. The term HIV-associated neurocognitive disorder (HAND) has been used to describe the spectrum of neurocognitive dysfunction associated with HIV infection. HIV can enter the CNS during early stages of infection, and persistent CNS HIV infection and inflammation probably contribute to the development of HAND. The brain can subsequently serve as a sanctuary for ongoing HIV replication, even when systemic viral suppression has been achieved. HAND can remain in patients treated with CART, and its effects on survival, quality of life and everyday functioning make it an important unresolved issue. In this Review, we describe the epidemiology of HAND, the evolving concepts of its neuropathogenesis, novel insights from animal models, and new approaches to treatment. We also discuss how inflammation is sustained in chronic HIV infection. Moreover, we suggest that adjunctive therapies--treatments targeting CNS inflammation and other metabolic processes, including glutamate homeostasis, lipid and energy metabolism--are needed to reverse or improve HAND-related neurological dysfunction.
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Affiliation(s)
- Deanna Saylor
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Alex M Dickens
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Ned Sacktor
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Norman Haughey
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Barbara Slusher
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Mikhail Pletnikov
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Joseph L Mankowski
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - Amanda Brown
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
| | - David J Volsky
- The Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, New York 10029, USA
| | - Justin C McArthur
- Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6113, 600 N Wolfe St, Baltimore, Maryland 21287, USA
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15
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Sun S, Yu H, Yu H, Honglin M, Ni W, Zhang Y, Guo L, He Y, Xue Z, Ni Y, Li J, Feng Y, Chen Y, Shao R, Chai R, Li H. Inhibition of the activation and recruitment of microglia-like cells protects against neomycin-induced ototoxicity. Mol Neurobiol 2015; 51:252-67. [PMID: 24781382 DOI: 10.1007/s12035-014-8712-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/09/2014] [Indexed: 12/18/2022]
Abstract
One of the most unfortunate side effects of aminoglycoside (AG) antibiotics such as neomycin is that they target sensory hair cells (HCs) and can cause permanent hearing impairment. We have observed HC loss and microglia-like cell (MLC) activation in the inner ear (cochlea) following neomycin administration. We focused on CX3CL1, a membrane-bound glycoprotein expressed on neurons and endothelial cells, as a way to understand how the MLCs are activated and the role these cells play in HC loss. CX3CL1 is the exclusive ligand for CX3CR1, which is a chemokine receptor expressed on the surface of macrophages and MLCs. In vitro experiments showed that the expression levels of CX3CL1 and CX3CR1 increased in the cochlea upon neomycin treatment, and CX3CL1 was expressed on HCs, while CX3CR1 was expressed on MLCs. When cultured with 1 μg/mL exogenous CX3CL1, MLCs were activated by CX3CL1, and the cytokine level was increased in the cochleae leading to apoptosis in the HCs. In CX3CR1 knockout mice, a significantly greater number of cochlear HCs survived than in wild-type mice when the cochlear explants were cultured with neomycin in vitro. Furthermore, inhibiting the activation of MLCs with minocycline reduced the neomycin-induced HC loss and improved the hearing function in neomycin-treated mice in vivo. Our results demonstrate that CX3CL1-induced MLC activation plays an important role in the induction of HC death and provide evidence for CX3CL1 and CX3CR1 as promising new therapeutic targets for the prevention of hearing loss.
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Affiliation(s)
- Shan Sun
- Research Center, Affiliated Eye and ENT Hospital of Fudan University, Shanghai, China
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16
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Sheridan GK, Wdowicz A, Pickering M, Watters O, Halley P, O'Sullivan NC, Mooney C, O'Connell DJ, O'Connor JJ, Murphy KJ. CX3CL1 is up-regulated in the rat hippocampus during memory-associated synaptic plasticity. Front Cell Neurosci 2014; 8:233. [PMID: 25161610 PMCID: PMC4130185 DOI: 10.3389/fncel.2014.00233] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/25/2014] [Indexed: 11/13/2022] Open
Abstract
Several cytokines and chemokines are now known to play normal physiological roles in the brain where they act as key regulators of communication between neurons, glia, and microglia. In particular, cytokines and chemokines can affect cardinal cellular and molecular processes of hippocampal-dependent long-term memory consolidation including synaptic plasticity, synaptic scaling and neurogenesis. The chemokine, CX3CL1 (fractalkine), has been shown to modulate synaptic transmission and long-term potentiation (LTP) in the CA1 pyramidal cell layer of the hippocampus. Here, we confirm widespread expression of CX3CL1 on mature neurons in the adult rat hippocampus. We report an up-regulation in CX3CL1 protein expression in the CA1, CA3 and dentate gyrus (DG) of the rat hippocampus 2 h after spatial learning in the water maze task. Moreover, the same temporal increase in CX3CL1 was evident following LTP-inducing theta-burst stimulation in the DG. At physiologically relevant concentrations, CX3CL1 inhibited LTP maintenance in the DG. This attenuation in dentate LTP was lost in the presence of GABAA receptor/chloride channel antagonism. CX3CL1 also had opposing actions on glutamate-mediated rise in intracellular calcium in hippocampal organotypic slice cultures in the presence and absence of GABAA receptor/chloride channel blockade. Using primary dissociated hippocampal cultures, we established that CX3CL1 reduces glutamate-mediated intracellular calcium rises in both neurons and glia in a dose dependent manner. In conclusion, CX3CL1 is up-regulated in the hippocampus during a brief temporal window following spatial learning the purpose of which may be to regulate glutamate-mediated neurotransmission tone. Our data supports a possible role for this chemokine in the protective plasticity process of synaptic scaling.
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Affiliation(s)
- Graham K Sheridan
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland ; Department of Physiology, Development and Neuroscience, University of Cambridge Cambridge, UK
| | - Anita Wdowicz
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Mark Pickering
- School of Medicine and Medical Science, Health Sciences Centre, University College Dublin Dublin, Ireland
| | - Orla Watters
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Paul Halley
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Niamh C O'Sullivan
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Claire Mooney
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - David J O'Connell
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - John J O'Connor
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Keith J Murphy
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
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17
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Role of fractalkine/CX3CL1 and its receptor in the pathogenesis of inflammatory and malignant diseases with emphasis on B cell malignancies. Mediators Inflamm 2014; 2014:480941. [PMID: 24799766 PMCID: PMC3985314 DOI: 10.1155/2014/480941] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/26/2014] [Accepted: 03/05/2014] [Indexed: 12/16/2022] Open
Abstract
Fractalkine/CX3CL1, the only member of the CX3C chemokine family, exists as a membrane-anchored molecule as well as in soluble form, each mediating different biological activities. It is constitutively expressed in many hematopoietic and nonhematopoietic tissues such as endothelial and epithelial cells, lymphocytes, neurons, microglial osteoblasts. The biological activities of CX3CL1 are mediated by CX3CR1, that is expressed on different cell types such as NK cells, CD14+ monocytes, cytotoxic effector T cells, B cells, neurons, microglia, smooth muscle cells, and tumor cells. The CX3CL1/CX3CR1 axis is involved in the pathogenesis of several inflammatory cancer including various B cell malignancies. In tumors the interaction between cancer cells and cellular microenvironment creates a context that may promote tumor growth, increase tumor survival, and facilitate metastasis. Therefore the role of the CX3CL1/CX3CR1 has attracted interest as to the development of potential therapeutic approaches. Here we review the different effects of the CX3CL1/CX3CR1 axis in several inflammatory and neurodegenerative diseases and in cancer, with emphasis on human B cell lymphomas.
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18
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Hu S, Sheng WS, Rock RB. CB2 receptor agonists protect human dopaminergic neurons against damage from HIV-1 gp120. PLoS One 2013; 8:e77577. [PMID: 24147028 PMCID: PMC3798286 DOI: 10.1371/journal.pone.0077577] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 09/03/2013] [Indexed: 11/18/2022] Open
Abstract
Despite the therapeutic impact of anti-retroviral therapy, HIV-1-associated neurocognitive disorder (HAND) remains a serious threat to AIDS patients, and there currently remains no specific therapy for the neurological manifestations of HIV-1. Recent work suggests that the nigrostriatal dopaminergic area is a critical brain region for the neuronal dysfunction and death seen in HAND and that human dopaminergic neurons have a particular sensitivity to gp120-induced damage, manifested as reduced function (decreased dopamine uptake), morphological changes, and reduced viability. Synthetic cannabinoids inhibit HIV-1 expression in human microglia, suppress production of inflammatory mediators in human astrocytes, and there is substantial literature demonstrating the neuroprotective properties of cannabinoids in other neuropathogenic processes. Based on these data, experiments were designed to test the hypothesis that synthetic cannabinoids will protect dopaminergic neurons against the toxic effects of the HIV-1 protein gp120. Using a human mesencephalic neuronal/glial culture model, which contains dopaminergic neurons, microglia, and astrocytes, we were able to show that the CB1/CB2 agonist WIN55,212-2 blunts gp120-induced neuronal damage as measured by dopamine transporter function, apoptosis and lipid peroxidation; these actions were mediated principally by the CB2 receptor. Adding supplementary human microglia to our cultures enhances gp120-induced damage; WIN55,212-2 is able to alleviate this enhanced damage. Additionally, WIN55,212-2 inhibits gp120-induced superoxide production by purified human microglial cells, inhibits migration of human microglia towards supernatants generated from gp120-stimulated human mesencephalic neuronal/glial cultures and reduces chemokine and cytokine production from the human mesencephalic neuronal/glial cultures. These data suggest that synthetic cannabinoids are capable of protecting human dopaminergic neurons from gp120 in a variety of ways, acting principally through the CB2 receptors and microglia.
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Affiliation(s)
- Shuxian Hu
- Center for Infectious Diseases and Microbiology Translational Research, Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Wen S. Sheng
- Center for Infectious Diseases and Microbiology Translational Research, Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - R. Bryan Rock
- Center for Infectious Diseases and Microbiology Translational Research, Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
- * E-mail:
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19
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Hauser KF, Fitting S, Dever SM, Podhaizer EM, Knapp PE. Opiate drug use and the pathophysiology of neuroAIDS. Curr HIV Res 2012; 10:435-52. [PMID: 22591368 PMCID: PMC3431547 DOI: 10.2174/157016212802138779] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/12/2012] [Accepted: 01/14/2012] [Indexed: 11/22/2022]
Abstract
Opiate abuse and HIV-1 have been described as interrelated epidemics, and even in the advent of combined anti-retroviral therapy, the additional abuse of opiates appears to result in greater neurologic and cognitive deficits. The central nervous system (CNS) is particularly vulnerable to interactive opiate-HIV-1 effects, in part because of the unique responses of microglia and astroglia. Although neurons are principally responsible for behavior and cognition, HIV-1 infection and replication in the brain is largely limited to microglia, while astroglia and perhaps glial progenitors can be latently infected. Thus, neuronal dysfunction and injury result from cellular and viral toxins originating from HIV-1 infected/exposed glia. Importantly, subsets of glial cells including oligodendrocytes, as well as neurons, express µ-opioid receptors and therefore can be direct targets for heroin and morphine (the major metabolite of heroin in the CNS), which preferentially activate µ-opioid receptors. This review highlights findings that neuroAIDS is a glially driven disease, and that opiate abuse may act at multiple glial-cell types to further compromise neuron function and survival. The ongoing, reactive cross-talk between opiate drug and HIV-1 co-exposed microglia and astroglia appears to exacerbate critical proinflammatory and excitotoxic events leading to neuron dysfunction, injury, and potentially death. Opiates enhance synaptodendritic damage and a loss of synaptic connectivity, which is viewed as the substrate of cognitive deficits. We especially emphasize that opioid signaling and interactions with HIV-1 are contextual, differing among cell types, and even within subsets of the same cell type. For example, astroglia even within a single brain region are heterogeneous in their expression of µ-, δ-, and κ-opioid receptors, as well as CXCR4 and CCR5, and Toll-like receptors. Thus, defining the distinct targets engaged by opiates in each cell type, and among brain regions, is critical to an understanding of how opiate abuse exacerbates neuroAIDS.
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Affiliation(s)
- Kurt F Hauser
- Department of Pharmacology and Toxicology, 1217 East Marshall Street, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, USA.
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20
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Fox HS, Gendelman HE. Commentary: Animal models of neuroAIDS. J Neuroimmune Pharmacol 2012; 7:301-5. [PMID: 22549136 DOI: 10.1007/s11481-012-9368-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 04/12/2012] [Indexed: 01/12/2023]
Affiliation(s)
- Howard S Fox
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5800, USA.
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21
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Suzuki M, El-Hage N, Zou S, Hahn YK, Sorrell ME, Sturgill JL, Conrad DH, Knapp PE, Hauser KF. Fractalkine/CX3CL1 protects striatal neurons from synergistic morphine and HIV-1 Tat-induced dendritic losses and death. Mol Neurodegener 2011; 6:78. [PMID: 22093090 PMCID: PMC3287119 DOI: 10.1186/1750-1326-6-78] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 11/17/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fractalkine/CX3CL1 and its cognate receptor CX3CR1 are abundantly expressed in the CNS. Fractalkine is an unusual C-X3-C motif chemokine that is important in neuron-microglial communication, a co-receptor for HIV infection, and can be neuroprotective. To assess the effects of fractalkine on opiate-HIV interactive neurotoxicity, wild-type murine striatal neurons were co-cultured with mixed glia from the striata of wild-type or Cx3cr1 knockout mice ± HIV-1 Tat and/or morphine. Time-lapse digital images were continuously recorded at 20 min intervals for up to 72 h using computer-aided microscopy to track the same cells repeatedly. RESULTS Co-exposure to Tat and morphine caused synergistic increases in neuron death, dendritic pruning, and microglial motility as previously reported. Exogenous fractalkine prevented synergistic Tat and morphine-induced dendritic losses and neuron death even though the inflammatory mediator TNF-α remained significantly elevated. Antibody blockade of CX3CR1 mimicked the toxic effects of morphine plus Tat, but did not add to their toxicity; while fractalkine failed to protect wild-type neurons co-cultured with Cx3cr1-/--null glia against morphine and Tat toxicity. Exogenous fractalkine also normalized microglial motility, which is elevated by Tat and morphine co-exposure, presumably limiting microglial surveillance that may lead to toxic effects on neurons. Fractalkine immunofluorescence was expressed in neurons and to a lesser extent by other cell types, whereas CX3CR1 immunoreactivity or GFP fluorescence in cells cultured from the striatum of Cx3cr1-/- (Cx3cr1GFP/GFP) mice were associated with microglia. Immunoblotting shows that fractalkine levels were unchanged following Tat and/or morphine exposure and there was no increase in released fractalkine as determined by ELISA. By contrast, CX3CR1 protein levels were markedly downregulated. CONCLUSIONS The results suggest that deficits in fractalkine-CX3CR1 signaling contribute to the synergistic neurotoxic effects of opioids and Tat. Importantly, exogenous fractalkine can selectively protect neurons from the injurious effects of chronic opioid-HIV-1 Tat co-exposure, and this suggests a potential therapeutic course for neuroAIDS. Although the cellular mechanisms underlying neuroprotection are not certain, findings that exogenous fractalkine reduces microglial motility and fails to protect neurons co-cultured with Cx3cr1-/- mixed glia suggest that fractalkine may act by interfering with toxic microglial-neuron interactions.
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Affiliation(s)
- Masami Suzuki
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298-0613, USA
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22
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Sosa RA, Forsthuber TG. The critical role of antigen-presentation-induced cytokine crosstalk in the central nervous system in multiple sclerosis and experimental autoimmune encephalomyelitis. J Interferon Cytokine Res 2011; 31:753-68. [PMID: 21919736 PMCID: PMC3189551 DOI: 10.1089/jir.2011.0052] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 06/23/2011] [Indexed: 12/17/2022] Open
Abstract
Multiple sclerosis (MS) is a debilitating disease of the central nervous system (CNS) that has been extensively studied using the animal model experimental autoimmune encephalomyelitis (EAE). It is believed that CD4(+) T lymphocytes play an important role in the pathogenesis of this disease by mediating the demyelination of neuronal axons via secretion of proinflammatory cytokines resulting in the clinical manifestations. Although a great deal of information has been gained in the last several decades about the cells involved in the inflammatory and disease mediating process, important questions have remained unanswered. It has long been held that initial neuroantigen presentation and T cell activation events occur in the immune periphery and then translocate to the CNS. However, an increasing body of evidence suggests that antigen (Ag) presentation might initiate within the CNS itself. Importantly, it has remained unresolved which antigen presenting cells (APCs) in the CNS are the first to acquire and present neuroantigens during EAE/MS to T cells, and what the conditions are under which this takes place, ie, whether this occurs in the healthy CNS or only during inflammatory conditions and what the related cytokine microenvironment is comprised of. In particular, the central role of interferon-γ as a primary mediator of CNS pathology during EAE has been challenged by the emergence of Th17 cells producing interleukin-17. This review describes our current understanding of potential APCs in the CNS and the contribution of these and other CNS-resident cells to disease pathology. Additionally, we discuss the question of where Ag presentation is initiated and under what conditions neuroantigens are made available to APCs with special emphasis on which cytokines may be important in this process.
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Affiliation(s)
- Rebecca A Sosa
- Department of Biology, University of Texas at San Antonio, Texas 78249, USA
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23
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Letendre SL, Zheng JC, Kaul M, Yiannoutsos CT, Ellis RJ, Taylor MJ, Marquie-Beck J, Navia B. Chemokines in cerebrospinal fluid correlate with cerebral metabolite patterns in HIV-infected individuals. J Neurovirol 2011; 17:63-9. [PMID: 21246320 PMCID: PMC3032187 DOI: 10.1007/s13365-010-0013-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 11/14/2010] [Accepted: 11/24/2010] [Indexed: 12/01/2022]
Abstract
Chemokines influence HIV neuropathogenesis by affecting the HIV life cycle, trafficking of macrophages into the nervous system, glial activation, and neuronal signaling and repair processes; however, knowledge of their relationship to in vivo measures of cerebral injury is limited. The primary objective of this study was to determine the relationship between a panel of chemokines in cerebrospinal fluid (CSF) and cerebral metabolites measured by proton magnetic resonance spectroscopy (MRS) in a cohort of HIV-infected individuals. One hundred seventy-one stored CSF specimens were assayed from HIV-infected individuals who were enrolled in two ACTG studies that evaluated the relationship between neuropsychological performance and cerebral metabolites. Concentrations of six chemokines (fractalkine, IL-8, IP-10, MCP-1, MIP-1β, and SDF-1) were measured and compared with cerebral metabolites individually and as composite neuronal, basal ganglia, and inflammatory patterns. IP-10 and MCP-1 were the chemokines most strongly associated with individual cerebral metabolites. Specifically, (1) higher IP-10 levels correlated with lower N-acetyl aspartate (NAA)/creatine (Cr) ratios in the frontal white matter and higher MI/Cr ratios in all three brain regions considered and (2) higher MCP-1 levels correlated with lower NAA/Cr ratios in frontal white matter and the parietal cortex. IP-10, MCP-1, and IL-8 had the strongest associations with patterns of cerebral metabolites. In particular, higher levels of IP-10 correlated with lower neuronal pattern scores and higher basal ganglia and inflammatory pattern scores, the same pattern which has been associated with HIV-associated neurocognitive disorders (HAND). Subgroup analysis indicated that the effects of IP-10 and IL-8 were influenced by effective antiretroviral therapy and that memantine treatment may mitigate the neuronal effects of IP-10. This study supports the role of chemokines in HAND and the validity of MRS as an assessment tool. In particular, the findings identify relationships between the immune response—particularly an interferon-inducible chemokine, IP-10—and cerebral metabolites and suggest that antiretroviral therapy and memantine modify the impact of the immune response on neurons.
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Affiliation(s)
- Scott L Letendre
- University of California, San Diego, 220 Dickinson Street, Suite A, San Diego, CA 92103, USA.
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Shapshak P, Kangueane P, Fujimura RK, Commins D, Chiappelli F, Singer E, Levine AJ, Minagar A, Novembre FJ, Somboonwit C, Nath A, Sinnott JT. Editorial neuroAIDS review. AIDS 2011; 25:123-41. [PMID: 21076277 PMCID: PMC4464840 DOI: 10.1097/qad.0b013e328340fd42] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Paul Shapshak
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, Tampa, Florida, USA
- Department of Psychiatry and Behavioral Medicine, University of South Florida, College of Medicine, Tampa, Florida, USA
| | - Pandjassarame Kangueane
- Biomedical Informatics, 17A lrulan Sundai Annex, Pondicherry, India
- AIMST University, Kedha, Malaysia
| | - Robert K. Fujimura
- Geriatric Research Education and Clinical Centers, Veterans Administration, Puget Sound Healthcare System, Seattle, Washington
| | - Deborah Commins
- Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles
| | | | - Elyse Singer
- Department of Neurology and National Neurological AIDS Bank, UCLA School of Medicine, Westwood, California
| | - Andrew J. Levine
- Department of Neurology and National Neurological AIDS Bank, UCLA School of Medicine, Westwood, California
| | - Alireza Minagar
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | | | - Charurut Somboonwit
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, Tampa, Florida, USA
- Clinical Research Unit, Hillsborough Health Department, Tampa, Florida
| | - Avindra Nath
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - John T. Sinnott
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, Tampa, Florida, USA
- Clinical Research Unit, Hillsborough Health Department, Tampa, Florida
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Soluble factors from IL-1β-stimulated astrocytes activate NR1a/NR2B receptors: implications for HIV-1-induced neurodegeneration. Biochem Biophys Res Commun 2010; 402:241-6. [PMID: 20933498 DOI: 10.1016/j.bbrc.2010.10.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Accepted: 10/02/2010] [Indexed: 11/20/2022]
Abstract
Astrocytes play an important role in astrocyte-neuron homeostasis. In HIV-1-infected brain, interleukin 1 beta (IL-1β) activation of astrocytes contributes to neurodegeneration. However, the molecular mechanisms underlying IL-1β-activated-astrocytes-induced neurodegeneration in HIV-1-infected brain are largely unknown. We hypothesize that secretory factors from the activated astrocytes affect N-methyl-d-aspartate (NMDA) receptor, a major pathway implicated in HIV-1-associated neurodegeneration. To test this hypothesis, we studied effects of IL-1β-stimulated astrocyte conditioned medium (ACM+) for its ability to activate NR1a/NR2B receptors expressed on Xenopus oocytes. Astrocytes treated with IL-1β 20ng/ml for 24h induced CXCL8, CCL2, MMP1 and MMP7. Pressure ejection of the ACM(+) produced an inward current in NR1a/NR2B-expressing oocytes. The inward current produced by ACM(+) was blocked by NMDA receptor antagonist, APV but not by non-NMDA receptor antagonist, CNQX. These results suggest that IL-1β stimulated astrocytes activate NR1a/NR2B receptors which may have implications in HIV-1-associated neurodegeneration.
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26
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Marchesi F, Locatelli M, Solinas G, Erreni M, Allavena P, Mantovani A. Role of CX3CR1/CX3CL1 axis in primary and secondary involvement of the nervous system by cancer. J Neuroimmunol 2010; 224:39-44. [PMID: 20630606 DOI: 10.1016/j.jneuroim.2010.05.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 05/04/2010] [Indexed: 12/12/2022]
Abstract
CX3CL1 or Fractalkine is a peculiar chemokine that can exist either in a soluble form, like all the other chemokines, and as a cell membrane molecule. CX3CL1 is one of the most expressed chemokines in the central nervous system, where it regulates the communication between neurons, glia and microglia. CX3CR1-expressing microglia may have an important role in limiting tissue injury during inflammation and neuro-degeneration. Recent evidence has implicated CX3CL1 and its cognate receptor CX3CR1 in cancer. Tumors of neural origin (glioma, neuroblastoma) express CX3CR1 which is involved in the adhesion, transendothelial migration and mobilization of tumor cells. In addition, tumors of non-neural origin, like prostate, pancreas and breast carcinoma express high levels of the CX3CR1 receptor. As for other chemokine receptors, CX3CR1 expression is associated with increased migration and site specific dissemination. In pancreatic cancer, receptor expression is involved in the perineural invasion and dissemination of neoplastic cells along intra- and extra-pancreatic nerves. This peculiar route of tumor spread is used also by other carcinomas (e.g. prostate, head and neck) and may represent a target for therapeutic intervention.
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Affiliation(s)
- Federica Marchesi
- Department of Immunology and Inflammation, IRCCS Humanitas Clinical Institute, Via Manzoni 56, 20089, Rozzano, Milan, Italy
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27
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Lauro C, Cipriani R, Catalano M, Trettel F, Chece G, Brusadin V, Antonilli L, van Rooijen N, Eusebi F, Fredholm BB, Limatola C. Adenosine A1 receptors and microglial cells mediate CX3CL1-induced protection of hippocampal neurons against Glu-induced death. Neuropsychopharmacology 2010; 35:1550-9. [PMID: 20200508 PMCID: PMC3055460 DOI: 10.1038/npp.2010.26] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fractalkine/CX3CL1 is a neuron-associated chemokine, which modulates microglia-induced neurotoxicity activating the specific and unique receptor CX3CR1. CX3CL1/CX3CR1 interaction modulates the release of cytokines from microglia, reducing the level of tumor necrosis factor-alpha, interleukin-1-beta, and nitric oxide and induces the production of neurotrophic substances, both in vivo and in vitro. We have recently shown that blocking adenosine A(1) receptors (A(1)R) with the specific antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) abolishes CX3CL1-mediated rescue of neuronal excitotoxic death and that CX3CL1 induces the release of adenosine from microglia. In this study, we show that the presence of extracellular adenosine is mandatory for the neurotrophic effect of CX3CL1 as reducing adenosine levels in hippocampal cultures, by adenosine deaminase treatment, strongly impairs CX3CL1-mediated neuroprotection. Furthermore, we confirm the predominant role of microglia in mediating the neuronal effects of CX3CL1, because the selective depletion of microglia from hippocampal cultures treated with clodronate-filled liposomes causes the complete loss of effect of CX3CL1. We also show that hippocampal neurons obtained from A(1)R(-/-) mice are not protected by CX3CL1 whereas A(2A)R(-/-) neurons are. The requirement of functional A(1)R for neuroprotection is not unique for CX3CL1 as A(1)R(-/-) hippocampal neurons are not rescued from Glu-induced cell death by other neurotrophins such as brain-derived neurotrophic factor and erythropoietin, which are fully active on wt neurons.
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Affiliation(s)
- Clotilde Lauro
- Istituto Pasteur, Fondazione Cenci Bolognetti, Rome, Italy,Centro di Eccellenza BEMM, Rome, Italy,Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy
| | - Raffaela Cipriani
- Istituto Pasteur, Fondazione Cenci Bolognetti, Rome, Italy,Centro di Eccellenza BEMM, Rome, Italy,Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy
| | - Myriam Catalano
- Istituto Pasteur, Fondazione Cenci Bolognetti, Rome, Italy,Centro di Eccellenza BEMM, Rome, Italy,Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy
| | - Flavia Trettel
- Istituto Pasteur, Fondazione Cenci Bolognetti, Rome, Italy,Centro di Eccellenza BEMM, Rome, Italy,Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy
| | - Giuseppina Chece
- Istituto Pasteur, Fondazione Cenci Bolognetti, Rome, Italy,Centro di Eccellenza BEMM, Rome, Italy,Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy
| | - Valentina Brusadin
- Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy
| | - Letizia Antonilli
- Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy
| | - Nico van Rooijen
- Department of Molecular Cell Biology, Free University Medical Center, Amsterdam, The Netherlands
| | - Fabrizio Eusebi
- Istituto Pasteur, Fondazione Cenci Bolognetti, Rome, Italy,Centro di Eccellenza BEMM, Rome, Italy,Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy,IRCSS NeuroMed, Pozzilli, Italy
| | - Bertil B Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Cristina Limatola
- Istituto Pasteur, Fondazione Cenci Bolognetti, Rome, Italy,Centro di Eccellenza BEMM, Rome, Italy,Dipartimento di Fisiologia e Farmacologia, Università Sapienza, Rome, Italy,IRCSS NeuroMed, Pozzilli, Italy,Dipartimento di Fisiologia e Farmacologia, Università di Roma Sapienza, Piazzale Aldo Moro, 5, Rome 00185, Italy. Tel: +39 06 49690243; Fax: +39 06 49910851; E-mail:
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28
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Yadav A, Collman RG. CNS inflammation and macrophage/microglial biology associated with HIV-1 infection. J Neuroimmune Pharmacol 2009; 4:430-47. [PMID: 19768553 PMCID: PMC5935112 DOI: 10.1007/s11481-009-9174-2] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 09/03/2009] [Indexed: 10/20/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection of the central nervous system (CNS) can result in neurological dysfunction with devastating consequences in a significant proportion of individuals with acquired immune deficiency syndrome. HIV-1 does not infect neurons directly but induces damage indirectly through the accumulation of activated macrophage/microglia (M/M) cells, some of which are infected, that release neurotoxic mediators including both cellular activation products and viral proteins. One mechanism for the accumulation of activated M/M involves the development in infected individuals of an activated peripheral blood monocyte population that traffics through the blood-brain barrier, a process that also serves to carry virus into CNS and establish local infection. A second mechanism involves the release by infected and activated M/M in the CNS of chemotactic mediators that recruit additional monocytes from the periphery. These activated M/M, some of which are infected, release a number of cytokines and small molecule mediators as well as viral proteins that act on bystander cells and in turn activate them, thus amplifying the cascade. These viral proteins and cellular products have neurotoxic properties as well, both directly and through induction of astrocyte dysfunction, which ultimately lead to neuronal injury and death. In patients effectively treated with antiretroviral therapy, frank dementia is now uncommon and has been replaced by milder forms of neurocognitive impairment, with less frequent and more focal neuropathology. This review summarizes key findings that support the critical role and mechanisms of monocyte/macrophage activation and inflammation as a major component for HIV-1 encephalitis or HIV-1 associated dementia.
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Affiliation(s)
- Anjana Yadav
- Department of Medicine and Center for AIDS Research, University of Pennsylvania School of Medicine, 522 Johnson Pavilion, 36th & Hamilton Walk, Philadelphia, PA 19104, USA
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New evidences for fractalkine/CX3CL1 involved in substantia nigral microglial activation and behavioral changes in a rat model of Parkinson's disease. Neurobiol Aging 2009; 32:443-58. [PMID: 19368990 DOI: 10.1016/j.neurobiolaging.2009.03.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 02/13/2009] [Accepted: 03/05/2009] [Indexed: 11/23/2022]
Abstract
Activated microglia are instrumental to neurodegeneration in Parkinson's disease (PD). Fractalkine, as an exclusive ligand for CX3CR1 expressed on microglia, has recently been reported to be released out by neurons, and induce microglial activation as a neuron-to-glia signal in the spinal cord. However, the role of fractalkine-induced microglial activation in PD remains unknown. In our study, we injected 1-methyl-4-phenylpyridinium (MPP(+)) into unilateral substantia nigra (SN) which induced ipsilateral endogenous fractalkine expression on neuron and observe the increase of CX3CR1 expression in response to MPP(+) by Western blotting analysis. Moreover, pre-administration of anti-CX3CR1 neutralizing antibody which potentially blocked microglial activation can promote rotation behaviors. To further investigate the role of fractalkine in PD, we injected exogenous fractalkine in unilateral SN, and observed microglial activation, dopaminergic cell depletion, and motor dysfunction. All these effects can be totally abolished by cerebroventricular administration of anti-CX3CR1. Intracerebroventricular administration of minocycline, a selective microglia inhibitor, can prevent fractalkine-induced rotation behaviors, and inhibit dopaminergic neurons from degeneration in the way of dose-dependent. Our studies demonstrate that fractalkine-induced microglial activation plays an important role in the development of PD, and provide an evidence of fractalkine and CX3CR1 as new therapeutic targets for PD treatment.
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30
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WIN55,212-2 inhibits production of CX3CL1 by human astrocytes: involvement of p38 MAP kinase. J Neuroimmune Pharmacol 2009; 4:244-8. [PMID: 19214751 DOI: 10.1007/s11481-009-9147-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 01/27/2009] [Indexed: 10/21/2022]
Abstract
CX3CL1 (fractalkine) has been shown not only to be neuroprotective but also may play a role in HIV-1-associated neuropathogenesis. In this study, we found that production of CX3CL1 by human astrocytes stimulated with interleukin (IL)-1beta was inhibited in a concentration-dependent manner following pretreatment with the synthetic cannabinoid WIN55,212-2. The CB(2) receptor selective antagonist SR144528 significantly inhibited WIN55,212-2-mediated suppression of CX3CL1, suggesting a CB(2)-receptor-related mechanism. IL-1beta triggered the activation of p38 and ERK1/2 (p44/42) MAP kinase (MAPK) signaling pathways, but WIN55,212-2 mainly inhibited p38 MAPK phosphorylation. This finding was mirrored in experiments using known inhibitors of these MAPKs, suggesting that the suppression of CX3CL1 production by WIN55,212-2 involves inhibition of signaling via p38 MAPK. Our results support the concept that synthetic cannabinoids have anti-inflammatory properties and that these agents may have therapeutic potential for certain neuroinflammatory disorders.
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31
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MFG-E8 regulates microglial phagocytosis of apoptotic neurons. J Neuroimmune Pharmacol 2008; 3:246-56. [PMID: 18670887 PMCID: PMC2832904 DOI: 10.1007/s11481-008-9118-2] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 07/07/2008] [Indexed: 11/21/2022]
Abstract
Phagocytosis is an essential mechanism for clearance of pathogens, dying cells, and other unwanted debris in order to maintain tissue health in the body. Macrophages execute this process in the peripheral immune system but in the brain microglia act as resident macrophages to accomplish this function. In the peripheral immune system, macrophages secrete Milk Fat Globule Factor-E8 (MFG-E8) that recognizes phosphatidylserine “eat me” signals expressed on the surface of apoptotic cells. MFG-E8 then acts as a tether to attach the apoptotic cell to the macrophage and trigger a signaling cascade that stimulates the phagocyte development, allowing the macrophage to engulf the dying cell. When this process becomes disrupted, inflammation and autoimmunity can result. MFG-E8 resides in the brain as well as in the periphery, and microglia express MFG-E8. However, the function of MFG-E8 in the brain has not been elucidated. We measured MFG-E8 production in the BV-2 microglial cell line and the role of this protein in the recognition and engulfment of apoptotic SY5Y neuroblastoma cells. BV-2 cells produced and released MFG-E8, which apoptotic SY5Y cells and the chemokine fractalkine further stimulated. Furthermore, MFG-E8 increased phagocytosis of apoptotic SY5Y cells, and a dominant negative form of MFG-E8 inhibited phagocytosis by BV-2 cells. Finally, brain MFG-E8 levels were altered in a mouse model of Alzheimer’s disease. Our data suggest that MFG-E8 acts in the brain via microglia to aid in clearance of apoptotic neurons, and we hypothesize that a dysregulation of this process may be involved in neurodegenerative disease.
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32
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Milligan ED, Sloane EM, Watkins LR. Glia in pathological pain: a role for fractalkine. J Neuroimmunol 2008; 198:113-20. [PMID: 18547654 PMCID: PMC3289257 DOI: 10.1016/j.jneuroim.2008.04.011] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Accepted: 04/10/2008] [Indexed: 01/01/2023]
Abstract
Microglia and/or astrocytes play a significant role in the creation and maintenance of exaggerated pain states with inflammatory and/or neuropathic etiologies. The chemokine, fractalkine, has several functions, including the newly recognized role of mediating neuropathic pain conditions. Although constitutively expressed and released during inflammation, increased release of fractalkine binds to and activates microglia leading to pathological pain. We review the critical role of fractalkine in neuron-to-glial communication after peripheral nerve injury and inflammation and explore anti-inflammatory cytokines like interleukin-10 as a novel and effective approach for clinical pain control.
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Affiliation(s)
- E D Milligan
- Department of Neurosciences, University of New Mexico, Health Sciences Center, Albuquerque, NM 87131-0001 USA.
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33
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HIV-1-infected and/or immune-activated macrophages regulate astrocyte CXCL8 production through IL-1beta and TNF-alpha: involvement of mitogen-activated protein kinases and protein kinase R. J Neuroimmunol 2008; 200:100-10. [PMID: 18653246 DOI: 10.1016/j.jneuroim.2008.06.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 06/13/2008] [Accepted: 06/16/2008] [Indexed: 01/06/2023]
Abstract
Monocyte infiltration is an important pathogenic event in human immunodeficiency virus type one (HIV-1) associated dementia (HAD). CXCL8 (Interleukin 8, IL-8), a CXC chemokine that elicits chemotaxis of neutrophils, has recently been found to recruit monocytes or synergistically enhance CCL2-mediated monocyte migration. In this report, we demonstrate CXCL8 levels in the cerebrospinal fluid of HAD patients are higher than HIV-1 seropositive patients without neurological impairment. The underlying mechanisms regulating CXCL8 production during disease are not completely understood. We investigated the role of HIV-1-infected and immune-competent macrophages, the principal target cell and mediator of neuronal injury in HAD, in regulating astrocyte CXCL8 production. Immune-activated and HIV-1-infected human monocyte-derived-macrophages (MDM) conditioned media (MCM) induced production of CXCL8 by human astrocytes. This CXCL8 production was dependent on MDM IL-1beta and TNF-alpha production following viral and immune activation. CXCL8 production was reduced by inhibitors for mitogen-activated protein kinases (MAPKs), including p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases (ERK1/2). Moreover, prolonged IL-1beta or TNF-alpha treatment activated double-stranded RNA-activated protein kinase (PKR). Inhibition of PKR prevented elevated CXCL8 production in astrocytes. We conclude that IL-1beta and TNF-alpha, produced from HIV-1-infected and immune-competent macrophages, are critical in astrocyte CXCL8 production. Multiple protein kinases, including p38, JNK, ERK1/2, and PKR, participate in the inflammatory response of astrocytes. These observations will help to identify effective therapeutic strategies to reduce high-levels of CXCL8-mediated CNS inflammation during HAD.
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Neuron-microglia signaling: Chemokines as versatile messengers. J Neuroimmunol 2008; 198:69-74. [DOI: 10.1016/j.jneuroim.2008.04.012] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 04/10/2008] [Indexed: 12/28/2022]
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35
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NeuroAIDS: characteristics and diagnosis of the neurological complications of AIDS. Mol Diagn Ther 2008; 12:25-43. [PMID: 18288880 DOI: 10.1007/bf03256266] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The neurological complications of AIDS (NeuroAIDS) include neurocognitive impairment and HIV-associated dementia (HAD; also known as AIDS dementia and HIV encephalopathy). HAD is the most significant and devastating central nervous system (CNS) complications associated with HIV infection. Despite recent advances in our knowledge of the clinical features, pathogenesis, and neurobiological aspects of HAD, it remains a formidable scientific and therapeutic challenge. An understanding of the mechanisms of HIV neuroinvasion, CNS proliferation, and HAD pathogenesis provide a basis for the interpretation of the diagnostic features of HAD and its milder form, HIV-associated minor cognitive/motor disorder (MCMD). Current diagnostic strategies are associated with significant limitations, but it is hoped that the use of biomarkers may assist researchers and clinicians in predicting the onset of the disease process and in evaluating the effects of new therapies.
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Abstract
In this review we critically assess biomarkers of the direct effects of HIV related brain disease. This area is becoming increasingly complex because of the presence of confounds and varying degrees of activity of HIV brain disease. Sensitive and specific biomarkers are urgently needed although existing biomarkers do have some utility. The review will focus on the practical implications of the more established biomarkers. We discuss blood, cerebrospinal fluid and neurophysiological biomarkers but not neuroimaging techniques as they are beyond the scope of this review.
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Affiliation(s)
- Bruce James Brew
- Departments of Neurology and HIV Medicine, St Vincent's Hospital, Sydney, Australia
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37
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Neuronal 'On' and 'Off' signals control microglia. Trends Neurosci 2007; 30:596-602. [PMID: 17950926 DOI: 10.1016/j.tins.2007.08.007] [Citation(s) in RCA: 550] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 07/18/2007] [Accepted: 08/03/2007] [Indexed: 11/24/2022]
Abstract
Recent findings indicate that neurons are not merely passive targets of microglia but rather control microglial activity. The variety of different signals that neurons use to control microglia can be divided into two categories: 'Off' signals constitutively keep microglia in their resting state and antagonize proinflammatory activity. 'On' signals are inducible and include purines, chemokines, glutamate. They instruct microglia activation under pathological conditions towards a beneficial or detrimental phenotype. Various neuronal signaling molecules thus actively control microglia function, thereby contribute to the inflammatory milieu of the central nervous system. Thus, neurons should be envisaged as key immune modulators in the brain.
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38
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de Haas AH, van Weering HRJ, de Jong EK, Boddeke HWGM, Biber KPH. Neuronal chemokines: versatile messengers in central nervous system cell interaction. Mol Neurobiol 2007; 36:137-51. [PMID: 17952658 PMCID: PMC2039784 DOI: 10.1007/s12035-007-0036-8] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Accepted: 01/17/2007] [Indexed: 01/07/2023]
Abstract
Whereas chemokines are well known for their ability to induce cell migration, only recently it became evident that chemokines also control a variety of other cell functions and are versatile messengers in the interaction between a diversity of cell types. In the central nervous system (CNS), chemokines are generally found under both physiological and pathological conditions. Whereas many reports describe chemokine expression in astrocytes and microglia and their role in the migration of leukocytes into the CNS, only few studies describe chemokine expression in neurons. Nevertheless, the expression of neuronal chemokines and the corresponding chemokine receptors in CNS cells under physiological and pathological conditions indicates that neuronal chemokines contribute to CNS cell interaction. In this study, we review recent studies describing neuronal chemokine expression and discuss potential roles of neuronal chemokines in neuron-astrocyte, neuron-microglia, and neuron-neuron interaction.
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Affiliation(s)
- A H de Haas
- Department of Medical Physiology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, Groningen, 9713 AV, The Netherlands
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Depboylu C, Eiden LE, Schäfer MKH, Reinhart TA, Mitsuya H, Schall TJ, Weihe E. Fractalkine expression in the rhesus monkey brain during lentivirus infection and its control by 6-chloro-2',3'-dideoxyguanosine. J Neuropathol Exp Neurol 2007; 65:1170-80. [PMID: 17146291 DOI: 10.1097/01.jnen.0000248550.22585.5e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Existing data concerning the role of the delta-chemokine fractalkine (CX3CL1) and its receptor (CX3CR1) in lentivirus-induced encephalitis are limited and controversial. We explored, by quantitative in situ hybridization and immunohistochemistry, the cell-specific changes of CX3CL1 and CX3CR1 in rhesus macaque brain during simian immunodeficiency virus (SIV) infection and antiretroviral treatment. Neuronal expression of CX3CL1 was significantly reduced in cortex and striatum of AIDS-diseased monkeys as compared with uninfected and asymptomatic SIV-infected monkeys. CX3CL1 mRNA was increased in some endothelial cells and newly induced in astrocytes and macrophages focally in areas of SIV burden and inflammatory infiltrates. In most CX3CL1-positive astrocytes and macrophages, the transcription factor NF-kappaB was translocated to the nucleus. CX3CR1 was upregulated in scattered, nodule, and giant cell-forming microglia/macrophages and mononuclear infiltrates close to CX3CL1-induced cells in the brain. Treatment of AIDS monkeys with the central nervous system-permeant 6-chloro-2',3'-dideoxyguanosine fully reversed SIV burden, productive inflammation, nuclear NF-kappaB translocation as well as focal induction of CX3CL1 in astrocytes and macrophages and downregulation in neurons. In contrast, diffuse CX3CR1-positive microgliosis and GFAP-positive astrogliosis were partially reversed by 6-chloro-2',3'-dideoxyguanosine. Thus, focally induced CX3CL1 may be a target for therapeutic intervention to limit ongoing inflammatory infiltration into brain in lentivirus infection.
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MESH Headings
- Active Transport, Cell Nucleus/drug effects
- Active Transport, Cell Nucleus/immunology
- Animals
- Anti-Retroviral Agents/therapeutic use
- Astrocytes/immunology
- Astrocytes/pathology
- Astrocytes/virology
- Brain/immunology
- Brain/pathology
- Brain/virology
- CX3C Chemokine Receptor 1
- Chemokine CX3CL1
- Chemokines, CX3C/genetics
- Chemokines, CX3C/metabolism
- Chemotaxis, Leukocyte/immunology
- Dideoxynucleosides/therapeutic use
- Disease Models, Animal
- Disease Progression
- Encephalitis, Viral/complications
- Encephalitis, Viral/drug therapy
- Encephalitis, Viral/immunology
- Endothelial Cells/immunology
- Endothelial Cells/pathology
- Endothelial Cells/virology
- Gene Expression Regulation/drug effects
- Gliosis/drug therapy
- Gliosis/immunology
- Gliosis/physiopathology
- Immunohistochemistry
- In Situ Hybridization
- Macaca mulatta
- Macrophages/immunology
- Macrophages/pathology
- Macrophages/virology
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- NF-kappa B/metabolism
- RNA, Messenger/analysis
- RNA, Messenger/metabolism
- Receptors, Chemokine/genetics
- Receptors, Chemokine/metabolism
- Simian Acquired Immunodeficiency Syndrome/complications
- Simian Acquired Immunodeficiency Syndrome/drug therapy
- Simian Acquired Immunodeficiency Syndrome/immunology
- Simian Immunodeficiency Virus/drug effects
- Simian Immunodeficiency Virus/immunology
- Treatment Outcome
- Viral Load
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Affiliation(s)
- Candan Depboylu
- Department of Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University, Robert-Koch-Strasse 8, 35032 Marburg, Germany
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Cinque P, Brew BJ, Gisslen M, Hagberg L, Price RW. Cerebrospinal fluid markers in central nervous system HIV infection and AIDS dementia complex. HANDBOOK OF CLINICAL NEUROLOGY 2007; 85:261-300. [PMID: 18808988 DOI: 10.1016/s0072-9752(07)85017-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Paola Cinque
- Clinic of Infectious Diseases, San Raffaele Scientific Institute, Milan, Italy
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Becker Y. The spreading of HIV-1 infection in the human organism is caused by fractalkine trafficking of the infected lymphocytes—a review, hypothesis and implications for treatment. Virus Genes 2006; 34:93-109. [PMID: 17151939 DOI: 10.1007/s11262-006-0056-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The reviews on HIV-1/AIDS [1-8] highlighted the mechanism by which HIV-1 virions utilize dendritic cells (DCs) for transport from the genitals, the portal of virus infection, to the draining lymph nodes where DCs carry HIV-1 virions and present viral antigens by HLA class I and II to CD4(+) T cells. Interaction of the T cells with viral antigens presented by HLA class II molecules polarizes them to become Th2 cells, the targets of HIV-1 infection and producers of HIV-1 progeny virions. The T cells which interact with viral antigen presented by HLA class I polarize to become Th1 cells, which stimulate the CD8(+) T cell precursors to develop into antiviral cytotoxic T cells. In addition, HIV-1 virions shed gp120 glycoprotein molecules which bind to IgE immunoglobulin molecules bound to FCepsilonRI+ innate system cells (basophils, mast cells and monocytes) and induce them to release large amounts of Th2 cytokines (IL-4, IL-5, IL-10, IL-13), thereby creating an allergy-like condition. The present review attempts to define the role of chemokine receptors like CCR5 and CXCR4, and especially fractalkine receptor CX3CR1 in the trafficking of lymphocytes in healthy individuals and HIV-1/AIDS patients. The role of chemokine receptors as co-receptors for HIV-1 virion gp120 glycoprotein has been defined, but the role of fractalkine and fractalkine receptor has been clarified only recently [9-19]. In healthy individuals fractalkine is expressed by blood vessel endothelial cells and the CX3CR1 receptors are expressed on leukocytes that migrate in the peripheral blood in the direction of increased fractalkine concentration. In HIV-1/AIDS patients the virus-infected CD4(+) Th2 cells migrate to organs that harbor the adaptive immune system cells in the thymus, genitals, gastrointestinal tract, and to the brain. A most significant finding which revealed the importance of the human CX3CR1 gene expression to the progression of the infection to the stage of AIDS was recently reported by Faure and collaborators [20, 21] who showed that the delayed or rapid progression to AIDS was affected in HIV-1-infected individuals who had inherited a fractalkine receptor gene with the polymorphisms V249I or T280M, respectively, located in the sixth and seventh transmembrane domains of CX3CR1 protein. The T280M mutation in the CX3CR1 gene caused a rapid progression to AIDS, while in patients with the V249I mutation progression to AIDS was much slower. These studies led to the idea that it might be possible to slow or prevent HIV-1/AIDS progression in HIV-1 patients by treating them with fractalkine antagonists that will bind to and inhibit the activity of the fractalkine receptor. It is hypothesized that treatment of HIV-1/AIDS patients with a combination of fractalkine antagonists, IL-4 antagonist IL-4delta2 and the adjuvant CpG ODN induced release of type I IFN from PDF, and may inhibit HIV-1 infection, especially in HAART-treated patients infected with drug-resistant HIV-1 mutants due to prevention of the availability of immune cells needed for the viral evasion of the immune response. The hypothesis implies that the advantage of the suggested mode of treatment of HIV-1-infected people is prevention of cellular processes that are used by the viral protein to cause immunodeficiency, and prevention of HIV-1 replication without induction of resistant mutants.
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Affiliation(s)
- Yechiel Becker
- Department of Molecular Virology, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
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Sun S, Cao H, Han M, Li TT, Pan HL, Zhao ZQ, Zhang YQ. New evidence for the involvement of spinal fractalkine receptor in pain facilitation and spinal glial activation in rat model of monoarthritis. Pain 2006; 129:64-75. [PMID: 17123734 DOI: 10.1016/j.pain.2006.09.035] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 08/23/2006] [Accepted: 09/28/2006] [Indexed: 10/23/2022]
Abstract
Fractalkine, a chemokine binding to only one known receptor CX3CR1, has recently been proposed to be a neuron-to-glia signal in the spinal cord leading to microglial activation and glially dependent pain facilitation. The previous studies explored that blockade of endogenous fractalkine, using anti-CX3CR1 neutralizing antibody, dose-dependently attenuated neuropathic pain. The present study examined the role of endogenous fractalkine in inflammatory pain. Intra-articular injection of complete Freund's adjuvant (CFA)-induced rat ankle joint monoarthritis (MA) model was used. Western blot analysis revealed that CX3CR1 expression in the spinal cord was significantly increased following CFA-induced MA. Intrathecal injection of anti-CX3CR1 neutralizing antibody both delayed the development of mechanical allodynia and thermal hyperalgesia, and reversed established pain facilitation. Furthermore, blockade of CX3CR1 significantly suppressed activation of spinal glia, especially microglia, evoked by MA. These data provided new evidence for the contribution of endogenous fractalkine to the initiation and early maintenance of inflammatory pain facilitation via activating spinal microglia.
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Affiliation(s)
- Shan Sun
- Institutes of Brain Science, Institute of Neurobiology, Fudan University, 138 Yixueyuan, Shanghai 200032, China
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43
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PENG HUI, ERDMANN NATHAN, WHITNEY NICHOLAS, DOU HUANGYU, GORANTLA SANTHI, GENDELMAN HOWARDE, GHORPADE ANUJA, ZHENG JIALIN. HIV-1-infected and/or immune activated macrophages regulate astrocyte SDF-1 production through IL-1beta. Glia 2006; 54:619-29. [PMID: 16944452 PMCID: PMC1919406 DOI: 10.1002/glia.20409] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Stromal cell-derived factor 1 alpha (SDF-1alpha) and its receptor CXCR4 play important roles in the pathogenesis of human immunodeficiency virus type one (HIV-1)-associated dementia (HAD) by serving as a HIV-1 co-receptor and affecting cell migration, virus-mediated neurotoxicity, and neurodegeneration. However, the underlying mechanisms regulating SDF-1 production during disease are not completely understood. In this report we investigated the role of HIV-1 infected and immune competent macrophage, the principal target cell and mediator of neuronal injury and death in HAD, in regulating SDF-1 production by astrocytes. Our data demonstrated that astrocytes are the primary cell type expressing SDF-1 in the brain. Immune-activated or HIV-1-infected human monocyte-derived-macrophage (MDM) conditioned media (MCM) induced a substantial increase in SDF-1 production by human astrocytes. This SDF-1 production was directly dependent on MDM IL-1beta following both viral and immune activation. The MCM-induced production of SDF-1 was prevented by IL-1beta receptor antagonist (IL-1Ra) and IL-1beta siRNA treatment of human MDM. These laboratory observations were confirmed in severe combined immunodeficient (SCID) mice with HIV-1 encephalitis (HIVE). In these HIVE mice, reactive astrocytes showed a significant increase in SDF-1 expression, as observed by immunocytochemical staining. Similarly, SDF-1 mRNA levels were increased in the encephalitic region as measured by real time RT-PCR, and correlated with IL-1beta mRNA expression. These observations provide direct evidence that IL-1beta, produced from HIV-1-infected and/or immune competent macrophage, induces production of SDF-1 by astrocytes, and as such contribute to ongoing SDF-1 mediated CNS regulation during HAD.
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Affiliation(s)
- HUI PENG
- Laboratory of Neurotoxicology, Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - NATHAN ERDMANN
- Laboratory of Neurotoxicology, Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - NICHOLAS WHITNEY
- Laboratory of Neurotoxicology, Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - HUANGYU DOU
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - SANTHI GORANTLA
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - HOWARD E. GENDELMAN
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - ANUJA GHORPADE
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pathology/Microbiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - JIALIN ZHENG
- Laboratory of Neurotoxicology, Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Pathology/Microbiology, University of Nebraska Medical Center, Omaha, Nebraska
- *Correspondence to: Department of Pharmacology/Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198–5880, USA. E-mail:
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Abstract
Human immunodeficiency virus-1 (HIV-1)-infected and immune-activated macrophages and microglia secrete neurotoxins. Two of these neurotoxins are the pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), which are thought to play a major role in inducing neuronal death. Both TNF-alpha and IL-1beta increase the permeability of the blood-brain barrier, through which subsequently HIV-infected monocytes can enter the brain. They both induce over-stimulation of the NMDA-receptor via several pathways, resulting in a lethal neuronal increase in Ca(2+) levels. Additionally, TNF-alpha co-operates with several other proinflammatory mediators to enhance their toxic effects. Although most research has focused on the neurotoxic effects of TNF-alpha and IL-1beta in HAD, there is also evidence that these cytokines can be neuroprotective. In this paper the effect of TNF-alpha and IL-1beta on neuronal life and death in HAD is discussed.
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Affiliation(s)
- N A C H Brabers
- Department of Virology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, the Netherlands
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Kadiu I, Glanzer JG, Kipnis J, Gendelman HE, Thomas MP. Mononuclear phagocytes in the pathogenesis of neurodegenerative diseases. Neurotox Res 2006; 8:25-50. [PMID: 16260384 DOI: 10.1007/bf03033818] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Brain mononuclear phagocytes (MP, bone marrow monocyte-derived macrophages, perivascular macrophages, and microglia) function to protect the nervous system by acting as debris scavengers, killers of microbial pathogens, and regulators of immune responses. MP are activated by a variety of environmental cues and such inflammatory responses elicit cell injury and death in the nervous system. MP immunoregulatory responses include secretion of neurotoxic factors, mobilization of adaptive immunity, and cell chemotaxis. This incites tissue remodelling and blood-brain barrier dysfunction. As disease progresses, MP secretions engage neighboring cells in a vicious cycle of autocrine and paracrine amplification of inflammation leading to tissue injury and ultimately destruction. Such pathogenic processes tilt the balance between the relative production of neurotrophic and neurotoxic factors and to disease progression. The ultimate effects that brain MP play in disease revolves "principally" around their roles in neurodegeneration. Importantly, common functions of brain MP in neuroimmunity link highly divergent diseases (for example, human immunodeficiency virus type-one associated dementia, Alzheimer's disease and Parkinson's disease). Research into this process from our own laboratories and those of others seek to harness MP inflammatory processes with the intent of developing therapeutic interventions that block neurodegenerative processes and improve the quality of life in affected people.
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Affiliation(s)
- I Kadiu
- Laboratory of Neuroregeneration, Department of Pharmacology and Experimental Neuroscience, Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA
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Milligan E, Zapata V, Schoeniger D, Chacur M, Green P, Poole S, Martin D, Maier SF, Watkins LR. An initial investigation of spinal mechanisms underlying pain enhancement induced by fractalkine, a neuronally released chemokine. Eur J Neurosci 2005; 22:2775-82. [PMID: 16324111 DOI: 10.1111/j.1460-9568.2005.04470.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fractalkine is a chemokine that is tethered to the extracellular surface of neurons. Fractalkine can be released, forming a diffusible signal. Spinal fractalkine (CX3CL1) is expressed by sensory afferents and intrinsic neurons, whereas its receptor (CX3CR1) is predominantly expressed by microglia. Pain enhancement occurs in response both to intrathecally administered fractalkine and to spinal fractalkine endogenously released by peripheral neuropathy. The present experiments examine whether fractalkine-induced pain enhancement is altered by a microglial inhibitor (minocycline) and/or by antagonists/inhibitors of three putative glial products implicated in pain enhancement: interleukin-1 (IL1), interleukin-6 (IL6) and nitric oxide (NO). In addition, it extends a prior study that demonstrated that intrathecal fractalkine-induced mechanical allodynia is blocked by a neutralizing antibody to the rat fractalkine receptor, CX3CR1. Here, intrathecal anti-CX3CR1 also blocked fractalkine-induced thermal hyperalgesia. Furthermore, blockade of microglial activation with minocycline prevented both fractalkine-induced mechanical allodynia (von Frey test) and thermal hyperalgesia (Hargreaves test). Microglial activation appears to lead to the release of IL1, given that pretreatment with IL1 receptor antagonist blocked both fractalkine-induced mechanical allodynia and thermal hyperalgesia. IL1 is not the only proinflammatory cytokine implicated, as a neutralizing antibody to rat IL6 also blocked fractalkine-induced pain facilitation. Lastly, NO appears to be importantly involved, as l-NAME, a broad-spectrum NO synthase inhibitor, also blocked fractalkine-induced effects. Taken together, these data support that neuronally released fractalkine enhances pain via activation of spinal cord glia. Thus, fractalkine may be a neuron-to-glia signal triggering pain facilitation.
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Affiliation(s)
- E Milligan
- Department of Psychology & Center for Neuroscience, University of Colorado at Boulder, Boulder, CO 80309-0345, USA
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Abstract
Since identification of the human immunodeficiency virus-1 (HIV-1), numerous studies suggest a link between neurological impairments, in particular dementia, with acquired immunodeficiency syndrome (AIDS) with alarming occurrence worldwide. Approximately, 60% of HIV-infected people show some form of neurological impairment, and neuropathological changes are found in 90% of autopsied cases. Approximately 30% of untreated HIV-infected persons may develop dementia. The mechanisms behind these pathological changes are still not understood. Mounting data obtained by in vivo and in vitro experiments suggest that neuronal apoptosis is a major feature of HIV associated dementia (HAD), which can occur in the absence of direct infection of neurons. The major pathway of neuronal apoptosis occurs indirectly through release of neurotoxins by activated cells in the central nervous system (CNS) involving the induction of excitotoxicity and oxidative stress. In addition a direct mechanism induced by viral proteins in the pathogenesis of HAD may also play a role. This review focuses on the molecular mechanisms of HIV-associated dementia and possible therapeutic strategies.
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Affiliation(s)
- Hakan Ozdener
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
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Navia BA, Rostasy K. The AIDS dementia complex: clinical and basic neuroscience with implications for novel molecular therapies. Neurotox Res 2005; 8:3-24. [PMID: 16260383 DOI: 10.1007/bf03033817] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The AIDS dementia complex (ADC, also referred to as HIV-associated cognitive impairment) is a common disorder among HIV-infected patients associated with both inflammatory and neurodegenerative processes. This review describes recent advances in the clinical and basic neurosciences of HIV infection and discusses the multivariable nature of what has become a chronic disorder in the context of highly active antiretroviral therapies (HAART). Since its initial description twenty years ago, advances in cell and molecular biology along with those in neuroimaging have furthered our understanding of the underlying pathogenic mechanisms. The clinical and neuropsychological profile of ADC is generally consistent with a "frontal-subcortical" pattern of injury. Neuropathogenesis is largely driven by indirect mechanisms mediated by infected, or more commonly, immune activated macrophages, which secrete viral and host-derived factors. Magnetic resonance spectroscopy (MRS) provides a robust in vivo method to measure the inflammatory and neurotoxic events triggered by these factors and their associated signals. Although the use of combined or highly active antiretroviral therapies (HAART) has significantly improved survival rates, cerebral injury and cognitive impairment remain common events. Factors such as aging and chronic infection will likely impact the course of this disease, its pathogenesis, and treatment. The combined observations presented in this review suggest a number of critical areas for future inquiry.
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Affiliation(s)
- B A Navia
- Department of Community Medicine, Tufts University School of Medicine, Boston MA, USA.
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Limatola C, Lauro C, Catalano M, Ciotti MT, Bertollini C, Di Angelantonio S, Ragozzino D, Eusebi F. Chemokine CX3CL1 protects rat hippocampal neurons against glutamate-mediated excitotoxicity. J Neuroimmunol 2005; 166:19-28. [PMID: 16019082 DOI: 10.1016/j.jneuroim.2005.03.023] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Accepted: 03/09/2005] [Indexed: 11/25/2022]
Abstract
Excitotoxicity is a cell death caused by excessive exposure to glutamate (Glu), contributing to neuronal degeneration in many acute and chronic CNS diseases. We explored the role of fractalkine/CX3CL1 on survival of hippocampal neurons exposed to excitotoxic doses of Glu. We found that: CX3CL1 reduces excitotoxicity when co-applied with Glu, through the activation of the ERK1/2 and PI3K/Akt pathways, or administered up to 8 h after Glu insult; CX3CL1 reduces the Glu-activated whole-cell current through mechanisms dependent on intracellular Ca2+; CX3CL1 is released from hippocampal cells after excitotoxic insult, likely providing an endogenous protective mechanism against excitotoxic cell death.
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Affiliation(s)
- Cristina Limatola
- Istituto Pasteur-Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza BEMM, Università di Roma La Sapienza, P.le A. Moro 5, I00185 Rome, Italy.
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Yajima N, Kasama T, Isozaki T, Odai T, Matsunawa M, Negishi M, Ide H, Kameoka Y, Hirohata S, Adachi M. Elevated levels of soluble fractalkine in active systemic lupus erythematosus: potential involvement in neuropsychiatric manifestations. ACTA ACUST UNITED AC 2005; 52:1670-5. [PMID: 15934075 DOI: 10.1002/art.21042] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To determine levels of the soluble form of the chemokine fractalkine (sFkn) and its receptor, CX(3)CR1, in patients with systemic lupus erythematosus (SLE) with neuropsychiatric involvement (NPSLE) and in SLE patients without neuropsychiatric involvement, and to assess their relationship with disease activity and organ damage. METHODS Levels of sFkn in serum and cerebrospinal fluid (CSF) were measured by enzyme-linked immunosorbent assay. Expression of Fkn and CX(3)CR1 was quantified using real-time polymerase chain reaction. Surface expression of CX(3)CR1 on peripheral blood mononuclear cells (PBMCs) was determined by flow cytometry. Disease activity and organ damage were assessed using the SLE Disease Activity Index (SLEDAI) and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index, respectively. RESULTS Serum sFkn levels were significantly higher in patients with SLE than in patients with rheumatoid arthritis (RA) or healthy controls. In addition, significant correlations between serum sFkn levels and the SLEDAI, the SLICC/ACR Damage Index, anti-double-stranded DNA and anti-Sm antibody titers, immune complex levels (C1q), and serum complement levels (CH50) were observed. Expression of CX(3)CR1 was significantly greater in PBMCs from patients with active SLE than in those from RA patients or healthy controls. Levels of sFkn were also significantly higher in CSF from untreated patients with newly diagnosed NPSLE than in SLE patients without neuropsychiatric involvement; treatment reduced both serum and CSF levels of sFkn in patients with SLE. CONCLUSION Soluble Fkn and CX(3)CR1 may play key roles in the pathogenesis of SLE, including the neuropsychiatric involvement. Soluble Fkn is also a serologic marker of disease activity and organ damage in patients with SLE, and its measurement in CSF may be useful for the diagnosis of NPSLE and followup of patients with NPSLE.
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MESH Headings
- Adult
- Biomarkers
- CX3C Chemokine Receptor 1
- Chemokine CX3CL1
- Chemokines, CX3C/analysis
- Chemokines, CX3C/blood
- Chemokines, CX3C/cerebrospinal fluid
- Female
- Humans
- Lupus Erythematosus, Systemic/blood
- Lupus Erythematosus, Systemic/cerebrospinal fluid
- Lupus Erythematosus, Systemic/physiopathology
- Lupus Vasculitis, Central Nervous System/blood
- Lupus Vasculitis, Central Nervous System/cerebrospinal fluid
- Lupus Vasculitis, Central Nervous System/physiopathology
- Male
- Membrane Proteins/analysis
- Membrane Proteins/biosynthesis
- Membrane Proteins/blood
- Membrane Proteins/cerebrospinal fluid
- Receptors, Chemokine/biosynthesis
- Severity of Illness Index
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